TORQUE SENSOR UNIT

摘要

Disclosed is a torque sensor unit including a magnetic member fixed to a first output shaft member, a pair of first and second yoke members fixed to an input shaft member and surrounding an outer circumferential side of the magnetic member and a magnetic sensor adapted to detect a magnetic flux passing through between the yoke members. The magnetic member is provided with a sleeve and a permanent magnet. The sleeve is formed of a metal material in a substantially cylindrical shape and has a plurality of radially extending support portions and a plurality of axially extending engagement protrusions between the support portions. The permanent magnet is formed into an annular shape and has a plurality of axially extending engagement grooves cut in an inner circumferential surface thereof. The permanent magnet and the sleeve are coupled via a resin-based filling material.

主权项

1. A torque sensor unit for detecting a torque applied to a rotating element, the rotating element having first and second shaft members formed of a metal material and connected to each other through a torsion bar, the torque sensor unit comprising:
a sleeve formed of a metal material and including: an annular or arc-shaped sleeve body surrounding the first shaft member; a fixing part provided on the sleeve body and fixing the sleeve body to the first shaft member; an axial position restricting part provided on the sleeve body and having a support surface directed vertically upward during use of the torque sensor unit; and a radial position restricting part provided on the sleeve body and extending in a direction of a rotation axis of the rotating element; an annular magnet formed of a composite material of resin and magnetic materials, with different magnetic poles alternately arranged in a circumferential direction, and surrounding the first shaft member, the magnet being placed on the support surface and thereby restricted in position in the direction of the rotation axis of the rotating element while being restricted in position in a radial direction by the radial position restricting part; a filling material formed from a resin material having a smaller Young's modulus than that of the magnet and held in intimate contact with the magnet and the radial position restricting part; a first yoke member formed of a magnetic material, fixed to the second shaft member so as to rotate together with the second shaft member and including: a plurality of first claw portions facing the magnet; and a first annular portion connecting the first claw portions; a second yoke member formed of a magnetic material, fixed to the second shaft member so as to rotate together with the second shaft member and including: a plurality of second claw portions circumferentially alternated with the first claw portions and facing the magnet; and a second annular portion connecting the second claw portions; and a magnetic sensor having a hall element to detect a change in magnetic field between the first and second yoke members and generate an output signal such that the torque applied to the rotating element can be detected based on the output signal from the magnetic sensor.