Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing
Bearing damage in modern inverter-fed AC drive systems is more common than in motors working with 50 or 60 Hz power supply. Fast switching transients and common mode voltage generated by a PWM inverter cause unwanted shaft voltage and resultant bearing currents. Parasitic capacitive coupling creates...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Conference Paper |
| Published: |
Institute of Electrical and Electronics Engineers ( IEEE )
2008
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| Online Access: | http://hdl.handle.net/20.500.11937/3466 |
| _version_ | 1848744239819653120 |
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| author | Adabi, J. zare, F. Ledwich, G. Ghosh, Arindam lorenz, R. |
| author2 | Unknown |
| author_facet | Unknown Adabi, J. zare, F. Ledwich, G. Ghosh, Arindam lorenz, R. |
| author_sort | Adabi, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Bearing damage in modern inverter-fed AC drive systems is more common than in motors working with 50 or 60 Hz power supply. Fast switching transients and common mode voltage generated by a PWM inverter cause unwanted shaft voltage and resultant bearing currents. Parasitic capacitive coupling creates a path to discharge current in rotors and bearings. In order to analyze bearing current discharges and their effect on bearing damage under different conditions, calculation of the capacitive coupling between the outer and inner races is needed. During motor operation, the distances between the balls and races may change the capacitance values. Due to changing of the thickness and spatial distribution of the lubricating grease, this capacitance does not have a constant value and is known to change with speed and load. Thus, the resultant electric field between the races and balls varies with motor speed. The lubricating grease in the ball bearing cannot withstand high voltages and a short circuit through the lubricated grease can occur. At low speeds, because of gravity, balls and shaft voltage may shift down and the system (ball positions and shaft) will be asymmetric. In this study, two different asymmetric cases (asymmetric ball position, asymmetric shaft position) are analyzed and the results are compared with the symmetric case. The objective of this paper is to calculate the capacitive coupling and electric fields between the outer and inner races and the balls at different motor speeds in symmetrical and asymmetrical shaft and balls positions. The analysis is carried out using finite element simulations to determine the conditions which will increase the probability of high rates of bearing failure due to current discharges through the balls and races. |
| first_indexed | 2025-11-14T05:58:19Z |
| format | Conference Paper |
| id | curtin-20.500.11937-3466 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T05:58:19Z |
| publishDate | 2008 |
| publisher | Institute of Electrical and Electronics Engineers ( IEEE ) |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-34662017-02-28T01:28:56Z Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing Adabi, J. zare, F. Ledwich, G. Ghosh, Arindam lorenz, R. Unknown Bearing damage in modern inverter-fed AC drive systems is more common than in motors working with 50 or 60 Hz power supply. Fast switching transients and common mode voltage generated by a PWM inverter cause unwanted shaft voltage and resultant bearing currents. Parasitic capacitive coupling creates a path to discharge current in rotors and bearings. In order to analyze bearing current discharges and their effect on bearing damage under different conditions, calculation of the capacitive coupling between the outer and inner races is needed. During motor operation, the distances between the balls and races may change the capacitance values. Due to changing of the thickness and spatial distribution of the lubricating grease, this capacitance does not have a constant value and is known to change with speed and load. Thus, the resultant electric field between the races and balls varies with motor speed. The lubricating grease in the ball bearing cannot withstand high voltages and a short circuit through the lubricated grease can occur. At low speeds, because of gravity, balls and shaft voltage may shift down and the system (ball positions and shaft) will be asymmetric. In this study, two different asymmetric cases (asymmetric ball position, asymmetric shaft position) are analyzed and the results are compared with the symmetric case. The objective of this paper is to calculate the capacitive coupling and electric fields between the outer and inner races and the balls at different motor speeds in symmetrical and asymmetrical shaft and balls positions. The analysis is carried out using finite element simulations to determine the conditions which will increase the probability of high rates of bearing failure due to current discharges through the balls and races. 2008 Conference Paper http://hdl.handle.net/20.500.11937/3466 Institute of Electrical and Electronics Engineers ( IEEE ) restricted |
| spellingShingle | Adabi, J. zare, F. Ledwich, G. Ghosh, Arindam lorenz, R. Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing |
| title | Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing |
| title_full | Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing |
| title_fullStr | Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing |
| title_full_unstemmed | Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing |
| title_short | Bearing Damage Analysis by Calculation of Capacitive Coupling between Inner and OuterRaces of a Ball Bearing |
| title_sort | bearing damage analysis by calculation of capacitive coupling between inner and outerraces of a ball bearing |
| url | http://hdl.handle.net/20.500.11937/3466 |