TORQUE SENSOR AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a torque sensor with a simple constitution reducing influence of a temperature drift for enhancing detection accuracy of torque. SOLUTION: This torque sensor 1 is provided with a cylindrical magnetostrictive material 3 externally fitted onto a shaft 2 and a stator 5 supported so as to rotate relatively to the shaft 2 via two bearings 4 fitted on both end parts of the magnetostrictive material 3. The stator 5 comprises a substantially cylindrical yoke 6 and two coil components 7 attached in an inner circumferential face of the yoke 6 in an embedded state. The yoke 6 is composed of a yoke main body 8 made of dust core material and two yoke rings 9 loosely fitted into both ends of the yoke main body 8. The yoke rings 9 are fixed in a state abutting to outer rings 4a of the bearings 4. Inner rings 4b of the bearings 4 are fixed by nuts 10 threadably attached to screw parts 3b formed on both end parts of the magnetostrictive material 3.