| CPC F16C 33/416 (2013.01) [F16C 33/418 (2013.01); F16C 33/6629 (2013.01)] | 38 Claims |

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1. A crown type cage for a ball bearing, which is made of resin, comprising:
an annular main portion;
a plurality of pillar portions protruding in an axial direction from the main portion at predetermined intervals in a peripheral direction; and
a spherical pocket formed between the adjacent pillar portions and capable of holding a ball, wherein
each pillar portion has a pair of claw portions of which tip end portions are spaced apart from each other and a connection portion that connects the pair of claw portions, and
a first surface of the main portion is provided with a first projection portion protruding in the axial direction, wherein
an inlet having a width shorter than a diameter of the ball and for inserting the ball is provided between the tip end portions of the two adjacent claw portions forming the pocket,
a radius of curvature of a spherical recessed surface of at least one pocket is greater than a radius of curvature of a rolling surface of the ball,
an outer diameter of at least one claw portion is smaller than an outer diameter of the main portion,
a radial width of at least one claw portion is ½ or less of a radial width of the main portion, and
an axial width from a first surface of the connection portion of at least one pillar portion to the first surface of the main portion is ½ or less of an axial width of the crown type cage for the ball bearing.
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