Patent ID: 9435703
Filing Date: 2016-09-06
CPC Classification: B62D,G01D,G01L

Claim Text:
1. A torque sensor that detects torque acting on a torsion bar that connects a first shaft and a second shaft, which are supported in a housing to be free to rotate, comprising: a magnetism generation portion that rotates together with the first shaft; a rotating magnetic circuit portion that rotates together with the second shaft; a fixed magnetic circuit portion fixed to the housing; a magnetism detector that detects a magnetic flux density guided from the magnetism generation portion to the fixed magnetic circuit portion through the rotating magnetic circuit portion in accordance with torsional deformation of the torsion bar; and a shield disposed between the rotating magnetic circuit portion and the magnetism detector, the shield being configured to shield the magnetism detector magnetically, wherein the rotating magnetic circuit portion comprises a first soft magnetic ring and a second soft magnetic ring to which magnetic flux generated by the magnetism generation portion is guided in accordance with the torsional deformation of the torsion bar, the fixed magnetic circuit portion comprises a first magnetic flux collecting yoke and a second magnetic flux collecting yoke disposed to face each other via a magnetic gap in which the magnetism detector is disposed, the shield is disposed between the first magnetic flux collecting yoke and the second magnetic flux collecting yoke via respective predetermined gaps, the shield is configured to guide flux leakage generated in the rotating magnetic circuit portion between the first magnetic flux collecting yoke and the second magnetic flux collecting yoke, and the shield, the first magnetic flux collecting yoke, and the second magnetic flux collecting yoke are arranged outside the first soft magnetic ring and the second soft magnetic ring in a radial direction.