| 摘要 |
PROBLEM TO BE SOLVED: To reduce a torque required for the self-rotation of a ball without increasing the movement of the ball on the inner side of a pocket. SOLUTION: Notches 6, 6 are formed in the inner surface of a pocket 3. An oil film may not be formed in a part where the inner surface of the pocket 3 and the rolling contact surface of a ball 4 are opposed to each other, and corresponds to the notches 6, 6, or if the oil film is formed therein, its thickness is thickened. The resistance of the ball 4 against its self-rotation, on the basis of the shearing resistance of the oil film, becomes small by the part of the oil film. Also, a lubricant flows through the notches 6, 6, therefore a lubrication condition can be stabilized. |
