QUT ePrints

Bearing damage analysis by calculation of capacitive coupling between inner and outer races of a ball bearing

Adabi Firouzjaee, Jafar, Zare, Firuz, Ledwich, Gerard, Ghosh, Arindam, & Lorenz, Robert (2008) Bearing damage analysis by calculation of capacitive coupling between inner and outer races of a ball bearing. In Power Electronics and Motion Control Conference, 2008. EPE-PEMC 2008. 13th, IEEE, Poland, pp. 903-907.

[img] Published Version (PDF 229kB)
Administrators only | Request a copy from author

    View at publisher

    Abstract

    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.

    Impact and interest:

    6 citations in Scopus
    Search Google Scholar™
    1 citations in Web of Science®

    Citation countsare sourced monthly from Scopus and Web of Science® citation databases.

    These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

    Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

    ID Code: 37663
    Item Type: Conference Paper
    Keywords: bearing failure , capacitive coupling , discharge current , shaft voltage , symmetrical and asymmetrical shaft position
    DOI: 10.1109/EPEPEMC.2008.4635382
    ISBN: 9781424417421 (elec.) 9781424417414 (print)
    Subjects: Australian and New Zealand Standard Research Classification > ENGINEERING (090000) > ELECTRICAL AND ELECTRONIC ENGINEERING (090600) > Power and Energy Systems Engineering (excl. Renewable Power) (090607)
    Divisions: Past > QUT Faculties & Divisions > Faculty of Built Environment and Engineering
    Past > Schools > School of Engineering Systems
    Copyright Owner: Copyright 2008 IEEE
    Deposited On: 30 Sep 2010 15:39
    Last Modified: 11 Dec 2013 14:53

    Export: EndNote | Dublin Core | BibTeX

    Repository Staff Only: item control page