| 摘要 |
PURPOSE:To improve the torque transmission performance of a bearing unit by simultaneously grinding four stripes of ball traveling surfaces arranged onto the both sides, needless to say two stripes of ball traveling surfaces arranged on one side of a hollow concaved part. CONSTITUTION:A bearing body 1 is loaded onto a working standard surface S, setting the hollow concaved part 2 on the upper side, and a cutting edge G1 is advanced at an entering angle alpha of about 50-65 deg. into the hollow concaved part 2, onto a pair of abrasive wheels G having a thickness and width T which are dressed to the equal curvature to that of a ball. In this case, each abrasive wheel G is arranged with a different phase in the longitudinal direction of the bearing body 1, and two stripes of ball traveling surfaces 7, 8 and 9, 10 can be ground at a same time, since the entering angle is reverse each other. Therefore, the finishing precision of the ball traveling surface can be increased, and torque transmission performance is improved, and noiseless traveling is permitted. |
