Patent ID: 6603305
Filing Date: 2003-08-05
Classification: G01D

Abstract:
A rotary encoder, comprising:a casing; a detection element attached to the casing; and a rotatable rotor having a mounting aperture for inserting a shaft at the center thereof and being provided with a code member opposing to the detection element, wherein an inner peripheral surface of the mounting aperture is provided with a spring member having a base and a plurality of tongues for energizing the shaft toward the center of the mounting aperture so as to set a position of the shaft at the center of the mounting aperture, and wherein the spring member is formed of a long hoop-shaped metal plate, the plurality of tongues are in series with the base of the spring member so as to project from the base, and the spring member has a cylindrical shape due to a cutting operation on a hoop material to a length corresponding to a length in a direction of the diameter of the shaft and the cylindrical spring member is disposed so as to be wound around the shaft.