To surely prevent separation of two annular members even when a ball rotational speed fluctuates due to sudden deceleration of a vehicle.
The ball bearing holder is constructed such that a plurality of semicircular pockets 12 are formed to house balls in the opposing surfaces 11 of two annular members 10 facing each other in an axial direction, and the opposing surfaces 11 are collided with each other to connect the two annular members 10. In each annular member 10, a tongue piece 15 is formed on the outer diameter side of one circumferential end of the pocket 12; a notch 17 is formed on the inner diameter side; a notch 18 is formed on the outer diameter side of the other peripheral end, and a tongue piece 16 is formed in the inner diameter side. Thus, the tongue pieces 15 and 16 and the notches 17 and 18 are alternately formed at both peripheral ends of the pocket 12 to connect the two annular members 10, the two tongue pieces 15 and 16 are fitted to the notches 17 and 18 from opposite directions.
Kunihiko Shiromura
Tsuyoshi Kumano