| 摘要 |
PROBLEM TO BE SOLVED: To increase the freedom of selection of the material for a rotating shaft and to reduce the cost of a magnetostrictive torque sensor. SOLUTION: This magnetostrictive torque sensor 110 comprises a magnetostrictive film 71 having a magnetostrictive characteristic changed according to working torque, which is provided on a rotating shaft 31 in a prescribed width W over the whole circumference; a substantially U-shaped exciting magnetic core 112 having an exciting coil 111 wound thereon, which is arranged opposite to the magnetostrictive film 71; and a substantially U-shaped detecting magnetic core 114 having a detecting coil 113 wound thereon, which is arranged in the state where the phase is shifted 90 deg. to the exciting magnetic core 112. A magnetic circuit is formed by the magnetic path passing the magnetostrictive film 71, the exciting coil 111 and the detecting coil 113. A bridge circuit is formed by the exciting coil 111 and the detecting coil 113. When a torque acts on the magnetostrictive film 71 through the rotating shaft 31, the magnetostrictive effect caused in the magnetostrictive film 71 according to this torque can be electrically detected in the bridge circuit. |
