Study on the running torque of angular contact ball bearings subjected to angular misalignment

Angular misalignment is unavoidable in most applications of rolling-element bearings. The goal of this study is to examine the effects of angular misalignment on the running torque of angular contact ball bearings. A computational method to calculate the running torque of misaligned angular contact ball bearings was introduced. Then, the effects of angular misalignment, along with radial and axial loading, on the running torque of angular contact ball bearings were investigated for two representative preloading methods: constant-force preload and constant-displacement preload. The simulation results showed that (1) the angular misalignment, irrespective of bearing loading, significantly increases the angular contact ball bearing running torque when the constant-displacement preload method was implemented, and (2) the angular misalignment has an insignificant effect on the angular contact ball bearing running torque when the constant-force preload method was adopted. Furthermore, an extensive simulation was performed to examine the effect of load-induced angular misalignment on the running torque of angular contact ball bearings implemented in a geared shaft system. The simulation results showed that the radial load-induced angular misalignment requires additional running torque to the actual rotor-bearing systems, especially when using the constant-displacement preload.