Patent ID: 9709095
Date: 2017-07-18
CPC Classifications: F16C

Claim:
1. A retainer, comprising two annular retaining plates combined with each other, the two annular retaining plates each having semispherical bulging portions arranged at predetermined intervals along a circumferential direction of the retainer, the semispherical bulging portions of the two annular retaining plates, which face each other, forming a pocket having a ring-like shape, for retaining a ball, wherein the pocket comprises a ball non-contact portion formed in a ball facing surface of the pocket at a center portion in a pocket axial direction, the ball non-contact portion being defined by a recess extending in a pocket circumferential direction, wherein an opening edge of the recess in the pocket axial direction, which defines the ball non-contact portion, has a rounded shape, wherein a curvature of the rounded shape is set to 0.05 to 0.30 mm, wherein the following relationship is set: where “A” represents a pocket circumferential length of the ball non-contact portion, “B” represents a diameter of the ball, and “C” represents a gap formed between the ball and the ball facing surface of the pocket, wherein the following relationship is set: where “D” represents a pocket axial length of the ball non-contact portion, and “E” represents an entire length of the pocket in an axial direction, and wherein the following relationship is set: where “F” represents a depth of the recess, which defines the ball non-contact portion, and “G” represents a thickness of each of the semispherical bulging portions of the two annular retaining plates.