Patent ID: 7311482
Filing Date: 2007-12-25
Classification: B23B,B23Q,Y10T

Abstract:
1. A spindle apparatus comprising: an outer cylinder having a stator; a rotatable rotating shaft having a rotor; a front side bearing having an outer ring fixed to a front housing and an inner ring fitted over one end of the rotating shaft; a bearing sleeve disposed on another end side of the rotating shaft and fitted in the outer cylinder so as to be movable in an axial direction of the rotating shaft; and a rear side bearing having an inner ring fitted over the other end of the rotating shaft and an outer ring fixed to the bearing sleeve to rotatably support the rotating shaft in cooperation with the front side bearing, wherein the diameter becomes smaller in the order of an inner peripheral diameter of the outer cylinder, an inside diameter of the stator, and an outside diameter of the bearing sleeve, wherein a sub-assembly made up of the front housing, the rotating shaft, and the bearing sleeve is withdrawable from the outer cylinder, wherein a radius of a rotating part in an arbitrary section located rearwardly of the bearing sleeve is smaller than a minimum radius of a non-rotating part between a rear end of the bearing sleeve and the section, and wherein the front housing is fitted to the outer cylinder with an interference fit.