White-Etching-Cracks-Detektion an Wälzlagern mit Laser-Doppler-Vibrometer
Failure modes, White Etching Cracks (WECs) and White Etching Areas (WEAs), ap-pear prevalently in rolling contact bearings. There is still a lack of efficient methods to identify such failure modes as early as possible before the visible crack appears on the bearing surface. In this article, a comparison was done between the measured opera-tional deflection shapes (ODS) from a rolling contact bearing with and without WECs and WEAs. The measurement was obtained by using a self-designed vibrometer robot system. A modal shaker was used to excite the bearing. The comparison was done by using the Cross Signature Assurance Criterion (CSAC), which checks the correlation between two ODS’s. The results show that the ODS’s from the bearing with and with-out WECs and WEAs are not correlated in the frequency spectrum. Therefore monitor-ing the ODS’s of the bearing by using the CSAC criterion seems to be feasible to de-tect the existence of WECs and WEAs in bearings. In order to check the applicability of the CSAC method, a further test was performed on a small-scaled bearing test bench by using a multipoint vibrometer. The results show that the CSAC method is applicable to detect changing of vibration behavior of the system even with influence from the drive unit of the test bench.