Analysis of contact characteristics of rolling bearings under load fluctuation

On the basis of considering the dynamic effect of bearing moving parts, the interaction between the roller and the cage was simulated by a nonlinear spring. A dynamic analysis model of the cylindrical roller bearing was established to research the internal contact characteristics of the rolling bearing under variable load. The Runge-Kutta algorithm with fourth-order fixed step was used to solve the differential equations of motion. The contact characteristics between the inner ring and the roller and its influence law under variable amplitude and frequency, as well as the dynamic contact characteristics of the cage under different forms of periodic fluctuating load were obtained. Results show that the collision between the roller and the front of the cage occurred in load zone, reversely, the collision between the roller and the rear of cage occurred in non-load zone. With the increase of fluctuation amplitude, the contact force between the roller and the inner ring increases in load zone, but the influence is small when entering and leaving the load zone. Under the action of low-frequency load, the trajectory of inner ring centroid is relatively concentrated, with the increase of fluctuation frequency, the load of the inner ring increases slowly, simultaneously, the inner ring tends to move upward. Under high frequency load the centroid trajectory of the inner ring is disordered and dispersed and the contact between the inner ring and the roller is unstable, the inner ring vibrates in the vertical direction. When load fluctuates, the degree of collision between the roller and the front of cage intensifies. The peak value of cage collision force from large to small is square wave, sine wave, triangular wave, and stable working condition. © 2023 Chinese Vibration Engineering Society. All rights reserved.