| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball bearing and a retainer thereof which inhibit deformation of a retainer during high speed rotation, stabilize a contact state between the retainer and balls, and is excellent also in acoustic aspects.SOLUTION: In a ball bearing consisting of an outer ring, an inner ring, a plurality of balls, and a retainer 5 that accommodates balls in pockets 18, the retainer is a coronary retainer which comprises an annular part 16 of one end side 15 in a shaft direction and pillar parts 19 which extend to other end side 17 in the shaft direction from the annular part to form a pocket in multiple places in a circumference direction, the pockets have an opening parts at another end side in the shaft direction, the entrance sizes of the opening parts are made smaller than ball diameters, and the outer periphery of the retainer has a cylindrical surface 21 from one end side in the shaft direction to a middle position in the shaft direction, and a sloping surface 22 which reduces the diameter toward the apex of the pillar part at the other end side in the shaft direction from the middle position. While the external diameter C at the apex of the pillar part are made smaller than ball PCD, the balls are made in touch with the pockets at points nearer the bearing center side than the ball PCD. |
