| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of fretting on the raceway surfaces of inner and outer rings by sufficiently suppressing the slight slippage of a rolling element even when positive/reverse fine rotation is changed over at a high speed. SOLUTION: A ball 4 as the rolling element is formed of ceramic and carbonitrided layers are formed in the raceway surfaces 2a, 3a of the inner ring 2 and the outer ring 3. A urea compound is used as thickening agent for grease 7 to be filled in a bearing space to suppress the slight slippage of the balls 4. Even when the slight slippage of the balls 4 is caused by the change-over of the positive/reverse fine rotation at a high speed, sufficient thickness of oil films are formed on the raceway surfaces 2a, 3a of the inner and outer rings 2, 3 to prevent the occurrence of fretting on the balls 4 as well as the raceway surfaces 2a, 3a of the inner and outer rings 2, 3. COPYRIGHT: (C)2007,JPO&INPIT |
