| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball screw device which can prevent the contact of a piston and a clutch at the block of power.SOLUTION: A ball screw device comprises: a piston 18 which is arranged at an external peripheral side of a nut 16 coaxially with the nut 16; a thrust bearing 22 which is arranged between the nut 16 and the piston 18 in an axial direction of a screw shaft 10; a nut-side lace salient part 38c and a nut-side recess 16d which regulate the relative movement of the nut 16 and the thrust bearing 22 to the axial direction of the screw shaft 10; and a piston-side lace salient part 40c and a piston-side recess 18d which regulate the relative movement of the piston 18 and the thrust bearing 22 to the axial direction of the screw shaft 10. The thrust bearing 22 comprises a bearing constitution holding mechanism which holds the integration of constituent components of the thrust bearing 22 even at the movement of the nut 16 to a direction in which the piston 18 separates from the clutch 6.SELECTED DRAWING: Figure 1 |
