| 摘要 |
PURPOSE:To improve transmission efficiency of torque by disposing retainers in front and in rear of an inner race and deepening a groove in a concave portion and a groove of an inner race. CONSTITUTION:A plurality of grooves 4b, 3c extending in the axial direction at spaces along the periphery are bored in the outer periphery of an inner race 4 and in the inner periphery of a concave portion 3a of an outer race 3. Thus, the concave spherical surface 3b of the outer race 3 and a convex spherical surface 4a of the inner race 4 are brought into sliding contact with each other to make the grooves 3c, 4b deep. Accordingly, an angle of the contact point (a) of the groove 3c with the ball 5 with a reference line passing the center of the ball 5 is increased about 65 deg.C to heighten transmission efficiency of torque. |
