| 摘要 |
PROBLEM TO BE SOLVED: To stably maintain the high lubricating performance of a ball bearing for a long period in spite of a less amount of grease by returning the grease scraped off by pockets to a raceway groove in the ball bearing. SOLUTION: Cutout portions 13 are provided between the pockets 12 of a crowned holder 11 where they are open to the other side face 17 of the holder in opposition to the opening sides of the pockets and overlapped with the bearing raceway groove 21, while one side face 11 of the holder with the open pockets is formed as a plane extending to the inside of the bearing raceway groove. The cutout portions 13 function as return passages for the grease during operation of the ball bearing to permit the return of the grease scraped off the surfaces of balls 20 of the ball bearing by the pockets 12 to the raceway groove 21 in the ball bearing with centrifugal force following the rotation of the crowned holder 11. |
