Patent ID: 8033195

Claim:
A low-noise screw device comprising: a screw shaft having a rolling-element rolling groove spirally formed on an outer peripheral surface thereof; a nut having a loaded rolling-element rolling groove spirally formed on an inner peripheral surface thereof, facing the rolling-element rolling groove of the screw shaft and having a rolling-element return path connecting an end of the loaded rolling-element rolling groove with an other end thereof; a plurality of rolling elements arranged in a loaded rolling-element rolling path between the rolling-element rolling groove of the screw shaft and the loaded rolling-element rolling groove of the nut and in the rolling-element return path; a flange provided at an axial end of the nut; and a plate having an outer diameter larger than an outer diameter of the nut and being provided over at least a part of an axial end surface of the flange that juts out from the nut so as to reduce noise generated from the end surface of the flange, wherein a step difference is provided between the end surface of the flange and an end surface of the nut, the plate has an outer-side plate part covering the end surface of the flange and an inner-side plate part provided to an inner side of the outer-side plate and covering the end surface of the nut, and the outer-side plate part is thicker than the inner-side plate part by a thickness corresponding to the step difference between the end surface of the nut and the end surface of the flange.