Patent ID: 8418570
Filing Date: 2013-04-16
Classification: B62D,G01L

Abstract:
1. A torque sensor that comprises a torsion bar that transmits a torque between a first shaft and a second shaft disposed coaxially, a magnetism generating portion fixed to the first shaft, and a rotating magnetic circuit portion fixed to the second shaft and detects a torque acting on the torsion bar based on a magnetic flux density led to the rotating magnetic circuit portion from the magnetism generating portion; the magnetism generating portion comprising: a back yoke that is fitted onto the first shaft; and a ring magnet that is joined to an end surface of the back yoke; and the back yoke comprising: a fitting portion that is fitted onto the first shaft; a projecting portion that projects from an end portion of the fitting portion in an axial direction of the first shaft; a joint portion to which the ring magnet is joined and that is formed on the projecting portion in a position offset from the fitting portion in the axial direction of the first shaft; and a stress reduction cutout that is a gap defined between the projecting portion and the first shaft and that is configured to suppress a transmission of a deformation stress generated in a radial direction of the fitting portion to the joint portion.