MAGNETOSTRICTIVE TORQUE SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a magnetostrictive torque sensor advantageous to the improvement of mountability. SOLUTION: This torque sensor is composed of a rotary shaft circumferentially rotated by a rotating drive source; a first bearing 3 and a second bearing 4 for rotatably holding the rotary shaft 2; an exciting part 5 for exciting the surface part of the rotary shaft 3; and a first detecting part and a second detecting part 7. The first detecting part 6 faces a spiral region 25 provided at the outer peripheral part of the rotary shaft 2. The spiral region 25 has a plurality of grooves 26 running parallel in spiral shape, and a plurality of ridges 27 running parallel in spiral shape between the grooves 26. The second detecting part 7 faces a nonspiral region 29 which is the smooth peripheral surface part of the rotary shaft 2. When the shaft length direction distance of the first bearing 3 and second bearing 4 denotes A and the outer diameter of the rotary shaft 2 denotes D, the A/D value is suppressed to be small.