Patent ID: 8424401

Claim:
A ball screw unit, comprising: a screw shaft that includes a screw groove; a ball screw nut that is screwed to the screw shaft via balls and that rotates to move the screw shaft linearly in an axial direction of the screw shaft; a hollow shaft that rotates together with the ball screw nut; a housing that rotatably supports the hollow shaft via a rolling bearing; and an elastic member that is provided at a position between the rolling bearing and the housing, such that the elastic member is sandwiched between the rolling bearing and the housing so as to allow the rolling bearing to move in an axial direction of the rolling bearing in relation to the housing, wherein a portion of a side face of the elastic member having a diameter less than an outer diameter of the rolling bearing abuts the rolling bearing and a portion of an opposite side face of the elastic member having a diameter less than the outer diameter of the rolling bearing abuts the housing.