Patent ID: 9302700
Filing Date: 2016-04-05
CPC Classification: B62D,G01L

Claim Text:
1. A torque sensor detecting a torque generated in a rotation member that is formed by a First shaft member and a second shaft member both of which are connected through a torsion bar, the torque sensor comprising: a magnetic member provided at the first shaft member so as to rotate integrally with the first shaft member and having different magnetic poles that are alternately arranged in a circumferential direction concentrically with a rotation axis of the rotation member; a first yoke member formed by magnetic material and provided at the second shaft member so as to rotate integrally with the second shaft member, the first yoke member having; (a) a plurality of first nail portions that are arranged concentrically with the rotation axis so as to face the magnetic member in a radial direction of the rotation axis; and (b) a first ring portion that connects the first nail portions together, a second yoke member formed by magnetic material and provided at the second shaft member so as to rotate integrally with the second shaft member the second yoke member having; (c) a plurality of second nail portions that are arranged concentrically with the rotation axis in such a way that the first nail portions and the second nail portions are alternately arranged in the circumferential direction and the second nail portions face the magnetic member in the radial direction of the rotation axis; and (d) a second ring portion that is arranged at an outer circumferential side of the first ring portion so as to be separated from and face the first ring portion and connects the second nail portions together, a first magnetic flux concentration ring formed by magnetic material and having a substantially arc-shape in a horizontally-cut cross section, the first magnetic flux concentration ring provided between the first ring portion and the second ring portion so that the first magnetic flux concentration ring and the first ring portion are arranged in layers each other in the radial direction and generating thereinside magnetic field by magnetic field generated in the first ring portion; a second magnetic flux concentration ring formed by magnetic material and having a substantially arc-shape in a horizontally-cut cross section, the second magnetic flux concentration ring provided between the second ring portion and the first magnetic flux concentration ring so that the second magnetic flux concentration ring and the second ring portion are arranged in layers each other in the radial direction and generating thereinside magnetic field by magnetic field generated in the second ring portion; and a magnetic sensor arranged between the first and second magnetic flux concentration rings and having a Hall device that detects a change of internal magnetic field between the first and second magnetic flux concentration rings which occurs by receiving the magnetic field between the first and second ring portions which changes according to a change of a relative angle between the first and second nail portions and the magnetic member in response to torsion deformation of the torsion bar, and the torque generated in the rotation member being detected on the basis of an output signal of the magnetic sensor.