Patent ID: 7928726
Filing Date: 2011-04-19
Classification: F16C,G01D,G01P

Abstract:
1. A rotation sensor unit comprising a rolling bearing having an outer race and an inner race, a housing in which said outer race of said rolling bearing is fitted, a shaft supported by said rolling bearing, a magnetic encoder for detecting rotation of said shaft, said magnetic encoder having an encoder and a magnetism detection element, said encoder being a magnet comprising north and south poles provided alternately in a circumferential direction around an axis of said shaft and rotatable coaxially and integrally with said shaft, said magnetism detection element axially facing said encoder, and a holder provided to position said encoder radially; wherein said inner race of said rolling bearing has an inner diameter surface fitted around said shaft with one end of said inner race protruding from a first end of an outer diameter surface of said shaft, wherein said encoder is positioned coaxially with said shaft by fitting said holder to said inner diameter surface of said inner race at said one end of said inner race; wherein said holder is made of a non-magnetic material; and wherein said holder comprises a retaining portion that retains said encoder and a screwed portion that extends between said retaining portion and the inner diameter surface of said inner race at said one end of said inner race, and wherein said screwed portion and said shaft are fixed to each other with non-magnetic screw members.