| 摘要 |
A return passage (R2) that connects two points of a rolling passage (R1) to allow each ball (32) that rolls in the rolling passage (R1) to endlessly circulate is formed in a ball screw nut (33) by attaching a circulation member (41) to fitting holes (42, 43). A protrusion (61) is formed on an outer surface (41a) of the circulation member (41) at a position offset from a raceway of the balls (32) that circulate in the return passage (R2). The circulation member (41) is fixed to the ball screw nut (33) when the protrusion (61) contacts an inner periphery of an inner ring (35a) of a second bearing (35). |
