Experimental Study on Contact Force in a Slewing Bearing

Measuring and verification of contact force in a rolling element bearing is a big problem. In this study, a new measuring method for contact force in a large-scale ball bearing is developed. The idea is to measure the deformation under the ball–race contact by displacement sensor at first, and the displacement of the end face of load bearing ring is also measured to determine the contact angle of ball–race contact. Then, the corresponding theory is developed to calculate the contact angle of ball–race contact by the displacement of the end face of load bearing ring. At last, the ball–race contact force is determined by accurately calculating through finite element method (FEM). Results show that the relation between contact force and deformation of measuring surface which is under ball–race contact is linear. The position of ball greatly affects the contact angle of ball–race contact. The contact angle of the ball which is near the arm of force is larger than that of the ball which is far from the arm of force. On the contrary, the measuring deformation of ball–race contact that is near the arm of force is less than that of ball–race contact that is far from the arm of force. The method developed here is only suitable for large-scale rolling element bearing because of the size constraint of the sensor.