Patent ID: 8339127
Filing Date: 2012-12-25
Classification: F16C,G01D,G01P

Abstract:
1. A rotation sensor unit comprising: a housing, a rolling bearing having an inner race, an outer race, and rolling elements disposed between the inner race and the outer race, the outer race of the rolling bearing being fitted in the housing; a shaft supported by the rolling bearing; a magnetic encoder for detecting rotation of the shaft; a lid facing one axial end surface of the shaft and axially pressed against one end of the housing; wherein said lid axially presses against one end surface of the outer race of the rolling bearing over an entire circumference thereof, thus applying a preload to the rolling bearing; wherein the magnetic encoder includes an encoder supported on the shaft, and a magnetic sensor element supported on the lid and disposed between the lid and the one axial end surface of the shaft; wherein the lid and the shaft are made of magnetic material; wherein the inner race, the outer race, and the rolling elements of the rolling bearing are made of magnetic material; and wherein a magnetically shielded space is defined by the lid, the one axial end surface of the shaft and the outer race of the rolling bearing, the magnetic sensor element being mounted in the magnetically shielded space.