| 摘要 |
Provided are: a retainer which is of low cost and which can provide the effect of low torque; and a ball bearing (deep groove ball bearing) in which the retainer is installed. A retainer is formed by combining two annular retaining plates (27A, 27B) having semispherical bulges (26) arranged at predetermined intervals in the circumferential direction and the opposing semispherical bulges (26, 26) form ring shaped pockets (30) for retaining balls (16). A section (32) which is not in contact with a ball (16) and which comprises a recess (34) extending in the circumferential direction of a pocket (30) is formed at the central part in the axial direction of the pocket (30) of the surface of the pocket (30) the surface facing the ball (16). If the length of the section (32) not in contact with the ball the length being measured in the circumferential direction of the pocket is A the diameter of the ball (16) is B and the size of the gap between the ball (16) and the surface of the pocket (30) which faces the ball (16) is C A/(B+C) is set in the range of 0.70 to 0.90. |
