Patent ID: 7246531
Filing Date: 2007-07-24
Classification: G01L

Abstract:
1. A torque sensor, comprising: a first shaft; a second shaft connected coaxially with the first shaft; a torsion bar of which one end is connected to the first shaft and the other end is connected to the second shaft, the torsion bar converting a torque applied between the first shaft and the second shaft into a torsion displacement; a multipolar magnet fixed to the first shaft or to the one end of the torsion bar; a pair of magnetic yokes fixed to the second shaft or to the other end of the torsion bar and disposed in a magnetic field generated by the multipolar magnet, the magnetic yokes being opposed to each other via an air gap in its axial direction; a magnetic sensor, disposed in the air gap of the magnetic yokes, which detects the density of the magnetic flux generated in the air gap; and a collar having a molding resin, wherein the magnetic yokes are fixed to the first or second shaft via the collar, a non-magnetic spacer is disposed between the magnetic yokes as a means for positioning the pair of magnetic yokes, the spacer and the pair of magnetic yokes are integrated by resin molding, the spacer has a single annular body, the pair of magnetic yokes are assembled to both end surfaces of the single annular body of the spacer, and the spacer has at least one positioning portion for positioning the pair of magnetic yokes.