Measuring the roller skew angle in the loading zone of a cylindrical roller bearing with strain gauges for long-term monitoring

Roller skew in roller bearings can cause heat generation in roller-race and roller-rib contacts, thus reducing bearing life. It is significant to obtain the roller skew angle in situ for guiding the bearing design and adjusting the operating conditions. In this study, a method for measuring the roller skew angle in the loading zone of a cylindrical roller bearing with strain gauges is presented. The measurement principle is that the roller skew angle is related to the movement of the contact line between the roller and raceway. The strain gauge array on the outer surface of the outer ring shows temporally separated responses when roller skew occurs. An experimental system is developed to validate the effectiveness of the proposed method for cylindrical roller bearing measurements. A laser measurement system is incorporated into the experimental system to detect the horizontal displacement of the reflected spot using a high-speed camera, which is then converted into the roller skew angle. The calculated roller skew angle from the time shift of the strain response agrees well with the value of a specially modified roller independently measured with the laser detection system. Compared with other measurement methods, the proposed method provides a potential way to achieve the nondestructive measurement of the roller skew angle in actual service for long-term purposes.