Patent ID: 7281851
Filing Date: 2007-10-16
Classification: F16C,G01D

Abstract:
1. A spindle device utilizing an externally pressurized gas bearing assembly, comprising: externally pressurized gas bearings to rotatably support a shaft of the spindle device; a motor to drive the shaft; and a rotary encoder to detect a rotational position of the shaft, wherein a pulse disc of the rotary encoder is fixed on a mounting surface, arranged in the vicinity of one end of the shaft and lying perpendicular to a central axis of the shaft, by a fastening member removably inserted through a fastening member inserting portion provided in the pulse disc, the mounting surface on which the pulse disc is fixed is an end face of a mounting base fixed to that end of the shaft and said mounting base is fixed to the shaft by a plurality of radially extending set screws, and screw holes for respective balance correcting members are provided on an end face or an outer peripheral surface of an outer peripheral portion of the mounting base and spaced an equal distance from each other along the circumference of the mounting base.