Influence of uneven loading condition on the sound radiation of starved lubricated full ceramic ball bearings

The effect of ball diameter difference is quite obvious in full ceramic bearings due to the great stiffness, and leads to the problem of uneven loading in starved lubricated conditions. This paper takes the uneven loading condition into consideration in the dynamic model, and a verification experiment is carried out for the assessment of calculation accuracy. The factors of ball diameter tolerance, the arrangements of balls and the number of balls have impact on the interactions between the inner ring and the loaded balls, and the trends of sound radiation are studied in depth. The amplitude of sound radiation is used to show the interaction between the elements, and uneven loading conditions can be evaluated by the sound directivity. Results show that the tolerance is a key factor that has impact on the sound radiation, and the sound radiation and directivity have obvious change with the ball diameter tolerance. The arrangements of balls have impact on the sound radiation by changing the diameter difference between adjacent balls, and the loaded area of each loaded ball varies with the number of balls. The cases with different numbers of loaded balls are discussed, and the relations between the uneven loading conditions and sound radiation are investigated. This study proposes a method for the study of uneven loading conditions, and provides theoretical basis for the optimal design of full ceramic bearings.