| 摘要 |
PROBLEM TO BE SOLVED: To prevent the relative axial movement or slippage of a bearing ring providing a bearing body having a spindle having a circumferential surface having a guide groove and a wall section concentrically surrounding the circumferential surface, and providing a ball mechanism having an entrained ball. SOLUTION: Parallel guide grooves 5, 5' extending spirally around a vertical axial line 3 are provided on the circumferential surface of a spindle by machining. A stroke member 6 has a flange 7 connectable to a moving component and a bearing body 8. The bearing body 8 has a sleeve having a cylindrical wall section 9. A power transmission device has at least one entrained mechanism each constituted as ball mechanisms 10, 10'. A bearing ring 12 has a lock device as one inside shoulder. Since the lock mechanism is provided in this manner, the bearing ring 12 can never slip in parallel to the vertical axial line 3 relatively to the ball mechanisms 10, 10'. |
