To prevent rotation of a nut member without requiring additional tightening of the nut member after the drag torque reaches a prescribed value and tightening of the nut member is stopped.

The bearing fixing device for fixing bearings 19 and 20 for supporting an turning output shaft 10 to a housing 15 includes the nut member 21 having a screw hole 21C and pressing the bearings 19 and 20 to the housing 15, a lock plate 41 having a spline part 41A fitted with a spline part 10C formed on the turning output shaft 10 and a bolt hole and fixed by the nut member 21, and a bolt 27 inserted into the bolt hole of the lock plate 41 and screwed into the screw hole 21C of the nut member 21 so as to fix the lock plate 41 to the nut member 21. The bolt hole of the lock plate 41 includes two oblong holes 41B extended along the circumferential direction of a circle drawn while having an axis of the turning output shaft 10 as a center.

COPYRIGHT: (C)2010,JPO&INPIT