Impact of axial loads on the sound directivity of angular contact ceramic ball bearings

This paper mainly focuses on the sound directivity of the angular contact ceramic ball bearing applied to the ceramic motorized spindle. The nonlinear dynamic model is proposed with consideration of axial load, nonlinear hydrodynamic forces and interaction between balls and cage. Then the sub-source decomposition method is introduced for the establishment of an acoustic radiation model. Sound pressure levels along the circumferential direction are used as evaluation indexes of sound directivity, and the sound directivity with axial loads at different rotation speed are analyzed. Results indicate that the sound directivity tends to be obvious with the increase of rotation speed, and the axial loads have significant influence on the deviation angles of directivity performance. This work provides insights into monitoring the acoustic performance of ceramic bearings, and can guide further research and development. (paper)