Bearing Damage Detection in Permanent Magnet Synchronous Machines.pdfVIP

Bearing Damage Detection in Permanent Magnet Synchronous Machines Mario Pacas Senior Member, IEEE Universitaet Siegen H?lderlinstrasse 3, 57068 Siegen, GERMANY jmpacas@ieee.org Sebastian Villwock Member, IEEE Baumüller Nürnberg Ostendstra?e 80-90, 90482 Nürnberg, GERMANY S.Villwock@baumueller.de Ralf Dietrich Baumüller Nürnberg Andernacher Str. 19, 90411 Nürnberg GERMANY R.Dietrich@bmr.baumueller.de Abstract -- The present work was performed in the frame of cooperation between Baumüller Nürnberg and the University of Siegen. This paper addresses the detection of damages of the bearings in servo motors and presents new results of the industrial application of a new developed diagnosis method for detecting such based on frequency response analysis. In the experimental work a permanent magnet synchronous machine (PMSM) is used and two different cases are considered: first, only the machine under no-load condition is investigated, afterwards the driving machine was installed in a two-mass- system simulating real conditions. The experimental results show that the method for damage detection works in both cases. In contrast to former publications the present paper shows results obtained on bearing faults in motors coming from the field to the repair shop. The measurement of the required signals (current and speed) can be accomplished during operation of the plant in closed loop speed control. The system is excited by pseudo random binary test-signals (PRBS). The deviations between the frequency response obtained during the commissioning of the plant and the curve measured under fault condition serve as indicators for the damage. Index Terms—Bearings, condition monitoring, electrical drives, fault diagnosis, frequency response. I. NOMENCLATURE dc: pitch diameter db: ball diameter di: bearing inner diameter do: bearing outer diameter z: number of rolling elements θ: ball contact angle JM: