PUBLIKACJE I PATENTY
2023
Breńkacz, A. Andrearczyk P. Bagiński Ł.
2023.
@patent{nokey,
title = {Sposób zmiany geometrii łożyska oraz łożysko folioweg [Patent application filed: The method of changing the geometry of the bearing and the foil bearing]},
author = {A. Andrearczyk P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=127},
year = {2023},
date = {2023-02-06},
urldate = {2023-02-06},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
2022
Breńkacz, P. Bagiński Ł.
2022.
@patent{nokeyb,
title = {Układ oraz sposób sterowania aktywnym łożyskiem foliowym [The arrangement and the method of controlling the active foil bearing]},
author = {P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=128},
year = {2022},
date = {2022-04-08},
urldate = {2022-04-08},
issue = {P.432715},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
Breńkacz, W. Janicki R. Kędra Ł.
Research on linear actuators for active foil bearings Journal Article
In: Materials, vol. 15, pp. 5694, 2022, ISSN: 19961944.
Abstract | Links | BibTeX | Tagi:
@article{nokeyc,
title = {Research on linear actuators for active foil bearings},
author = {W. Janicki R. Kędra Ł. Breńkacz},
url = {https://www.mdpi.com/1996-1944/15/16/5694},
doi = {10.3390/ma15165694},
issn = {19961944},
year = {2022},
date = {2022-01-01},
journal = {Materials},
volume = {15},
pages = {5694},
abstract = {Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings. Witanowski, N. Szewczuk-Krypa Ł. Breńkacz Ł.
Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 377-385, 2022, ISBN: 1507-2711.
Abstract | Links | BibTeX | Tagi:
@article{nokeyd,
title = {Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings},
author = {N. Szewczuk-Krypa Ł. Breńkacz Ł. Witanowski},
doi = {http://doi.org/10.17531/ein.2022.2.19},
isbn = {1507-2711},
year = {2022},
date = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {377-385},
abstract = {In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine. Breńkacz, M. Adamowicz P. Bagiński Ł.
Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 177-185, 2022, ISSN: 1507-2711.
Abstract | Links | BibTeX | Tagi:
@article{nokeye,
title = {Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator},
author = {M. Adamowicz P. Bagiński Ł. Breńkacz},
url = {https://ein.org.pl/Author-Marek-Adamowicz/212427},
doi = {https://doi.org/10.17531/ein.2022.1.20},
issn = {1507-2711},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {177-185},
abstract = {Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.2021
Breńkacz, N. Szewczuk-Krypa Ł.
Taking into account fluid-structure interactions in the basic control model of an active foil bearing Conference
Institute of Fluid Flow Machinery, Polish Academy of Sciences Wdzydze Kiszewskie, Poland, 2021.
@conference{nokeyf,
title = {Taking into account fluid-structure interactions in the basic control model of an active foil bearing},
author = {N. Szewczuk-Krypa Ł. Breńkacz},
editor = {B. Kraszewski P. Ziółkowski},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
address = {Wdzydze Kiszewskie, Poland},
organization = {Institute of Fluid Flow Machinery, Polish Academy of Sciences},
abstract = {The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed. Breńkacz, Ł.
Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications Book
John Wiley & Sons Ltd., 2021, ISBN: 9781119759263.
Abstract | Links | BibTeX | Tagi:
@book{nokeyg,
title = {Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications},
author = {Ł. Breńkacz},
url = {https://onlinelibrary.wiley.com/doi/book/10.1002/9781119759287},
doi = {10.1002/9781119759287},
isbn = {9781119759263},
year = {2021},
date = {2021-01-01},
publisher = {John Wiley & Sons Ltd.},
series = {Wiley-ASME Press},
abstract = {A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject. Breńkacz, M. Drosińska-Komor Ł. Witanowski Ł.
Research and applications of active bearings: A state-of-the-art review Journal Article
In: Mechanical Systems and Signal Processing, vol. 151, pp. 107423, 2021, ISSN: 0888-3270.
Abstract | Links | BibTeX | Tagi:
@article{nokeyh,
title = {Research and applications of active bearings: A state-of-the-art review},
author = {M. Drosińska-Komor Ł. Witanowski Ł. Breńkacz},
url = {https://www.sciencedirect.com/science/article/pii/S0888327020308098},
doi = {10.1016/j.ymssp.2020.107423},
issn = {0888-3270},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Mechanical Systems and Signal Processing},
volume = {151},
pages = {107423},
abstract = {Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).2020
Breńkacz, Ł. Witanowski N. Szewczuk-Krypa Ł.
The basic control model of an active foil bearing Conference
2020.
Abstract | Links | BibTeX | Tagi:
@conference{nokeyi,
title = {The basic control model of an active foil bearing},
author = {Ł. Witanowski N. Szewczuk-Krypa Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=151},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
abstract = {The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.
2023
Breńkacz, A. Andrearczyk P. Bagiński Ł.
2023.
@patent{nokey,
title = {Sposób zmiany geometrii łożyska oraz łożysko folioweg [Patent application filed: The method of changing the geometry of the bearing and the foil bearing]},
author = {A. Andrearczyk P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=127},
year = {2023},
date = {2023-02-06},
urldate = {2023-02-06},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
2022
Breńkacz, P. Bagiński Ł.
2022.
@patent{nokeyb,
title = {Układ oraz sposób sterowania aktywnym łożyskiem foliowym [The arrangement and the method of controlling the active foil bearing]},
author = {P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=128},
year = {2022},
date = {2022-04-08},
urldate = {2022-04-08},
issue = {P.432715},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
Breńkacz, W. Janicki R. Kędra Ł.
Research on linear actuators for active foil bearings Journal Article
In: Materials, vol. 15, pp. 5694, 2022, ISSN: 19961944.
Abstract | Links | BibTeX | Tagi:
@article{nokeyc,
title = {Research on linear actuators for active foil bearings},
author = {W. Janicki R. Kędra Ł. Breńkacz},
url = {https://www.mdpi.com/1996-1944/15/16/5694},
doi = {10.3390/ma15165694},
issn = {19961944},
year = {2022},
date = {2022-01-01},
journal = {Materials},
volume = {15},
pages = {5694},
abstract = {Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings.
Witanowski, N. Szewczuk-Krypa Ł. Breńkacz Ł.
Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 377-385, 2022, ISBN: 1507-2711.
Abstract | Links | BibTeX | Tagi:
@article{nokeyd,
title = {Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings},
author = {N. Szewczuk-Krypa Ł. Breńkacz Ł. Witanowski},
doi = {http://doi.org/10.17531/ein.2022.2.19},
isbn = {1507-2711},
year = {2022},
date = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {377-385},
abstract = {In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine.
Breńkacz, M. Adamowicz P. Bagiński Ł.
Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 177-185, 2022, ISSN: 1507-2711.
Abstract | Links | BibTeX | Tagi:
@article{nokeye,
title = {Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator},
author = {M. Adamowicz P. Bagiński Ł. Breńkacz},
url = {https://ein.org.pl/Author-Marek-Adamowicz/212427},
doi = {https://doi.org/10.17531/ein.2022.1.20},
issn = {1507-2711},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {177-185},
abstract = {Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.
2021
Breńkacz, N. Szewczuk-Krypa Ł.
Taking into account fluid-structure interactions in the basic control model of an active foil bearing Conference
Institute of Fluid Flow Machinery, Polish Academy of Sciences Wdzydze Kiszewskie, Poland, 2021.
@conference{nokeyf,
title = {Taking into account fluid-structure interactions in the basic control model of an active foil bearing},
author = {N. Szewczuk-Krypa Ł. Breńkacz},
editor = {B. Kraszewski P. Ziółkowski},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
address = {Wdzydze Kiszewskie, Poland},
organization = {Institute of Fluid Flow Machinery, Polish Academy of Sciences},
abstract = {The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed.
Breńkacz, Ł.
Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications Book
John Wiley & Sons Ltd., 2021, ISBN: 9781119759263.
Abstract | Links | BibTeX | Tagi:
@book{nokeyg,
title = {Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications},
author = {Ł. Breńkacz},
url = {https://onlinelibrary.wiley.com/doi/book/10.1002/9781119759287},
doi = {10.1002/9781119759287},
isbn = {9781119759263},
year = {2021},
date = {2021-01-01},
publisher = {John Wiley & Sons Ltd.},
series = {Wiley-ASME Press},
abstract = {A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.
Breńkacz, M. Drosińska-Komor Ł. Witanowski Ł.
Research and applications of active bearings: A state-of-the-art review Journal Article
In: Mechanical Systems and Signal Processing, vol. 151, pp. 107423, 2021, ISSN: 0888-3270.
Abstract | Links | BibTeX | Tagi:
@article{nokeyh,
title = {Research and applications of active bearings: A state-of-the-art review},
author = {M. Drosińska-Komor Ł. Witanowski Ł. Breńkacz},
url = {https://www.sciencedirect.com/science/article/pii/S0888327020308098},
doi = {10.1016/j.ymssp.2020.107423},
issn = {0888-3270},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Mechanical Systems and Signal Processing},
volume = {151},
pages = {107423},
abstract = {Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).
2020
Breńkacz, Ł. Witanowski N. Szewczuk-Krypa Ł.
The basic control model of an active foil bearing Conference
2020.
Abstract | Links | BibTeX | Tagi:
@conference{nokeyi,
title = {The basic control model of an active foil bearing},
author = {Ł. Witanowski N. Szewczuk-Krypa Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=151},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
abstract = {The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.
2023
Breńkacz, A. Andrearczyk P. Bagiński Ł.
2023.
@patent{nokey,
title = {Sposób zmiany geometrii łożyska oraz łożysko folioweg [Patent application filed: The method of changing the geometry of the bearing and the foil bearing]},
author = {A. Andrearczyk P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=127},
year = {2023},
date = {2023-02-06},
urldate = {2023-02-06},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
2022
Breńkacz, P. Bagiński Ł.
2022.
@patent{nokeyb,
title = {Układ oraz sposób sterowania aktywnym łożyskiem foliowym [The arrangement and the method of controlling the active foil bearing]},
author = {P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=128},
year = {2022},
date = {2022-04-08},
urldate = {2022-04-08},
issue = {P.432715},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
Breńkacz, W. Janicki R. Kędra Ł.
Research on linear actuators for active foil bearings Journal Article
In: Materials, vol. 15, pp. 5694, 2022, ISSN: 19961944.
@article{nokeyc,
title = {Research on linear actuators for active foil bearings},
author = {W. Janicki R. Kędra Ł. Breńkacz},
url = {https://www.mdpi.com/1996-1944/15/16/5694},
doi = {10.3390/ma15165694},
issn = {19961944},
year = {2022},
date = {2022-01-01},
journal = {Materials},
volume = {15},
pages = {5694},
abstract = {Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings. Witanowski, N. Szewczuk-Krypa Ł. Breńkacz Ł.
Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 377-385, 2022, ISBN: 1507-2711.
@article{nokeyd,
title = {Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings},
author = {N. Szewczuk-Krypa Ł. Breńkacz Ł. Witanowski},
doi = {http://doi.org/10.17531/ein.2022.2.19},
isbn = {1507-2711},
year = {2022},
date = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {377-385},
abstract = {In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine. Breńkacz, M. Adamowicz P. Bagiński Ł.
Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 177-185, 2022, ISSN: 1507-2711.
@article{nokeye,
title = {Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator},
author = {M. Adamowicz P. Bagiński Ł. Breńkacz},
url = {https://ein.org.pl/Author-Marek-Adamowicz/212427},
doi = {https://doi.org/10.17531/ein.2022.1.20},
issn = {1507-2711},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {177-185},
abstract = {Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.2021
Breńkacz, N. Szewczuk-Krypa Ł.
Taking into account fluid-structure interactions in the basic control model of an active foil bearing Conference
Institute of Fluid Flow Machinery, Polish Academy of Sciences Wdzydze Kiszewskie, Poland, 2021.
@conference{nokeyf,
title = {Taking into account fluid-structure interactions in the basic control model of an active foil bearing},
author = {N. Szewczuk-Krypa Ł. Breńkacz},
editor = {B. Kraszewski P. Ziółkowski},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
address = {Wdzydze Kiszewskie, Poland},
organization = {Institute of Fluid Flow Machinery, Polish Academy of Sciences},
abstract = {The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed. Breńkacz, Ł.
Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications Book
John Wiley & Sons Ltd., 2021, ISBN: 9781119759263.
@book{nokeyg,
title = {Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications},
author = {Ł. Breńkacz},
url = {https://onlinelibrary.wiley.com/doi/book/10.1002/9781119759287},
doi = {10.1002/9781119759287},
isbn = {9781119759263},
year = {2021},
date = {2021-01-01},
publisher = {John Wiley & Sons Ltd.},
series = {Wiley-ASME Press},
abstract = {A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject. Breńkacz, M. Drosińska-Komor Ł. Witanowski Ł.
Research and applications of active bearings: A state-of-the-art review Journal Article
In: Mechanical Systems and Signal Processing, vol. 151, pp. 107423, 2021, ISSN: 0888-3270.
@article{nokeyh,
title = {Research and applications of active bearings: A state-of-the-art review},
author = {M. Drosińska-Komor Ł. Witanowski Ł. Breńkacz},
url = {https://www.sciencedirect.com/science/article/pii/S0888327020308098},
doi = {10.1016/j.ymssp.2020.107423},
issn = {0888-3270},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Mechanical Systems and Signal Processing},
volume = {151},
pages = {107423},
abstract = {Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).2020
Breńkacz, Ł. Witanowski N. Szewczuk-Krypa Ł.
The basic control model of an active foil bearing Conference
2020.
@conference{nokeyi,
title = {The basic control model of an active foil bearing},
author = {Ł. Witanowski N. Szewczuk-Krypa Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=151},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
abstract = {The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.
2023
Breńkacz, A. Andrearczyk P. Bagiński Ł.
2023.
@patent{nokey,
title = {Sposób zmiany geometrii łożyska oraz łożysko folioweg [Patent application filed: The method of changing the geometry of the bearing and the foil bearing]},
author = {A. Andrearczyk P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=127},
year = {2023},
date = {2023-02-06},
urldate = {2023-02-06},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
2022
Breńkacz, P. Bagiński Ł.
2022.
@patent{nokeyb,
title = {Układ oraz sposób sterowania aktywnym łożyskiem foliowym [The arrangement and the method of controlling the active foil bearing]},
author = {P. Bagiński Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=128},
year = {2022},
date = {2022-04-08},
urldate = {2022-04-08},
issue = {P.432715},
keywords = {},
pubstate = {published},
tppubtype = {patent}
}
Breńkacz, W. Janicki R. Kędra Ł.
Research on linear actuators for active foil bearings Journal Article
In: Materials, vol. 15, pp. 5694, 2022, ISSN: 19961944.
@article{nokeyc,
title = {Research on linear actuators for active foil bearings},
author = {W. Janicki R. Kędra Ł. Breńkacz},
url = {https://www.mdpi.com/1996-1944/15/16/5694},
doi = {10.3390/ma15165694},
issn = {19961944},
year = {2022},
date = {2022-01-01},
journal = {Materials},
volume = {15},
pages = {5694},
abstract = {Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Active foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed based on different mechanical concepts. This paper provides an analysis of the linear mechanisms that are the base, and they are crucial for such developments. In the literature, there is a lack of characteristics of these actuators tested under real operating conditions of an active foil bearing. This article aims to fill this gap. New test rigs have been developed and used to precisely investigate the possibility of using actuators in active foil bearings. Since their geometry and control methods differ, the measurement systems have been adapted accordingly. The actuators studied were piezoelectrics, shape-memory alloys (SMAs) and stepper motors. Each of them was characterized by different operating characteristics. The results obtained allow for a comparison of the actuators. This approach is especially useful for the design and analysis of active foil bearings.
Witanowski, N. Szewczuk-Krypa Ł. Breńkacz Ł.
Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 377-385, 2022, ISBN: 1507-2711.
@article{nokeyd,
title = {Comparable analysis of PID controller settings in order to ensure reliable operation of active foil bearings},
author = {N. Szewczuk-Krypa Ł. Breńkacz Ł. Witanowski},
doi = {http://doi.org/10.17531/ein.2022.2.19},
isbn = {1507-2711},
year = {2022},
date = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {377-385},
abstract = {In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In comparison to the traditional solutions, active bearings offer great operating flexibility, ensure better operating conditions over a wider range of rotational speeds and are safe to use. In order to ensure optimum bearing performance a bearing control system is used that adapts different geometries during device operation. The selection of optimal controller parameters requires the use of modern optimization methods that make it possible to quickly achieve the assumed parameters. This article presents the method that has been employed to select the parameters of a proportional integral derivative (PID) controller, in which both stochastic algorithms and hybrid methods have been compared. The results show that all of the used algorithms were able to reach the global optimum but only the hybrid algorithm was repeatable in all runs within a low value of the standard deviation. The best solution will be proposed in the future to control an active foil bearing. Analysing of this paper would help to prevent failures of active foil bearing used in the designed rotating machine.
Breńkacz, M. Adamowicz P. Bagiński Ł.
Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator Journal Article
In: Eksploatacja i Niezawodnosc – Maintenance and Reliability, vol. 24, pp. 177-185, 2022, ISSN: 1507-2711.
@article{nokeye,
title = {Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator},
author = {M. Adamowicz P. Bagiński Ł. Breńkacz},
url = {https://ein.org.pl/Author-Marek-Adamowicz/212427},
doi = {https://doi.org/10.17531/ein.2022.1.20},
issn = {1507-2711},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Eksploatacja i Niezawodnosc – Maintenance and Reliability},
volume = {24},
pages = {177-185},
abstract = {Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Due to ongoing research work, a prototype test rig for testing high speed motors/generators has been developed. Its design is quite unique as the two high speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.
2021
Breńkacz, N. Szewczuk-Krypa Ł.
Taking into account fluid-structure interactions in the basic control model of an active foil bearing Conference
Institute of Fluid Flow Machinery, Polish Academy of Sciences Wdzydze Kiszewskie, Poland, 2021.
@conference{nokeyf,
title = {Taking into account fluid-structure interactions in the basic control model of an active foil bearing},
author = {N. Szewczuk-Krypa Ł. Breńkacz},
editor = {B. Kraszewski P. Ziółkowski},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
address = {Wdzydze Kiszewskie, Poland},
organization = {Institute of Fluid Flow Machinery, Polish Academy of Sciences},
abstract = {The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The main objective of the paper is to present the control model of an active foil bearing, in which fluid-structure interactions are taken into account. The active foil bearing is a modification of the classic foil bearing [1]. In the presented system, changes in the geometry of the bearing bush are enabled by actuators. The analysed radial foil bearing has a variable geometry. The changes influence the lubrication gap and the shape of the foil. Such a bearing allows for optimizing the dynamic properties [2]. To enable proper operation, the displacement of the shaft needs to be measured by two displacement sensors. Based on the measurements, the trajectory of the rotating shaft can be obtained. The control system is based on a PID controller [3] which connects the measurement sensors with the actuators. The data from the measurement sensors are compared with the maximum allowed value of the vibration amplitude and, if necessary, the vibration level can be reduced to eliminate resonant vibrations. The possibilities of applying the proposed model are discussed.
Breńkacz, Ł.
Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications Book
John Wiley & Sons Ltd., 2021, ISBN: 9781119759263.
@book{nokeyg,
title = {Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications},
author = {Ł. Breńkacz},
url = {https://onlinelibrary.wiley.com/doi/book/10.1002/9781119759287},
doi = {10.1002/9781119759287},
isbn = {9781119759263},
year = {2021},
date = {2021-01-01},
publisher = {John Wiley & Sons Ltd.},
series = {Wiley-ASME Press},
abstract = {A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
A guide to bearing dynamic coefficients in rotordynamics that includes various computation methods
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.
Bearing Dynamic Coefficients in Rotordynamics delivers an authoritative guide to the fundamentals of bearing and bearing dynamic coefficients containing various computation methods. Three of the most popular and state-of-the-art methods of determining coefficients are discussed in detail. The computation methods covered include an experimental linear method created by the author, and numerical linear and nonlinear methods using the finite element method. The author—a renowned expert on the topic—presents the results and discusses the limitations of the various methods.
Accessibly written, the book provides a clear analysis of the fundamental phenomena in rotor dynamics and includes many illustrations from numerical analysis and the results of the experimental research. Filled with practical examples, the book also includes a companion website hosting code used to calculate the dynamic coefficients of journal bearings. This important book:
Covers examples of different computation methods, presents results, and discusses limitations of each
Reviews the fundamentals of bearing and bearing dynamic coefficients
Includes illustrations from the numerical analysis and results of the experimental research
Offers myriad practical examples and a companion website
Written for researchers and practitioners working in rotordynamics, Bearing Dynamic Coefficients in Rotordynamics will also earn a place in the libraries of graduate students in mechanical and aerospace engineering who seek a comprehensive treatment of the foundations of this subject.
Breńkacz, M. Drosińska-Komor Ł. Witanowski Ł.
Research and applications of active bearings: A state-of-the-art review Journal Article
In: Mechanical Systems and Signal Processing, vol. 151, pp. 107423, 2021, ISSN: 0888-3270.
@article{nokeyh,
title = {Research and applications of active bearings: A state-of-the-art review},
author = {M. Drosińska-Komor Ł. Witanowski Ł. Breńkacz},
url = {https://www.sciencedirect.com/science/article/pii/S0888327020308098},
doi = {10.1016/j.ymssp.2020.107423},
issn = {0888-3270},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Mechanical Systems and Signal Processing},
volume = {151},
pages = {107423},
abstract = {Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Controllable/active bearings are mainly associated with active magnetic bearings (AMBs), whereas active bearing control is also found in many types of bearings, e.g. fluid, gas and hybrid bearings. The article presents a review of the literature describing the structure and results of studies of active bearings. Active control brings a number of benefits resulting in the fact that their use as a support for rotors becomes increasingly common. This article introduces readers to the different methods of controlling radial bearings and provides detailed information on various technical solutions. Furthermore, the paper presents the characteristics of bearings as well as the basic advantages, disadvantages and possibilities offered by active control of various types of bearings. The influence of active control on rotor dynamics as well as on bearing friction, temperature control, permissible operating time, the environment (possibility of using safer lubricants) and operating safety is presented. The final part of the article presents possible directions of development of active bearings (ABs).
2020
Breńkacz, Ł. Witanowski N. Szewczuk-Krypa Ł.
The basic control model of an active foil bearing Conference
2020.
@conference{nokeyi,
title = {The basic control model of an active foil bearing},
author = {Ł. Witanowski N. Szewczuk-Krypa Ł. Breńkacz},
url = {http://www.brenkacz.com/index.php/extensions-3/roksprocket-3/artykuly-naukowe-2?view=publication&task=show&id=151},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
abstract = {The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The article presents the conception of a foil bearing control system, in which a feedback loop is used. The purpose of this system is to improve the dynamic properties of the active foil bearing by changing its geometry. In the system presented, the change in the geometry relates to the size of the lubrication gap and the bearing foils. The system consists of a shaft driven by an electro spindle and radial foil bearings with variable geometry. The system whose main task is to optimise the dynamic properties of a bearing consists of three integrated subsystems. The first subsystem is used to measure the position of the bearing and consists of displacement sensors which are arranged in pairs, perpendicularly to the rotor axis. This arrangement of the sensors makes it possible to determine the displacements of the bearing bush in two directions perpendicular to each other. This subsystem also enables signal processing, which allows to calculate the maximum vibration amplitude (based on measured displacements) in two mutually perpendicular directions. A properly processed signal is analysed by the control subsystem to determine the displacements of the bearing components, which can ensure the change of the dynamic properties of the rotor-bearing system during operation. At the initial stage of the research, it was assumed that the control system would be implemented through the appropriate type of controller. The change of the bearing bush is carried out by the executive subsystem that uses actuators. The changes introduced indirectly, by changing the dynamic properties of the gas film and the supporting foils of the foil bearing, make it possible, among other things, to reduce the vibration level and eliminate resonance vibrations.