Torque sensor

Abstract

Abstract PURPOSE:To detect the change in torque of a rotary shaft with small power consumption in a simple structure, by providing a magnetic flux generating part on the rotary shaft, and providing a magnetic sensor comprising a plurality of magnetoresistance effect elements in the vicinity of the rotary shaft. CONSTITUTION:In the vicinity of a rotary shaft 1, a magnetic field generating means 25 such as a permanent magnet 25 is arranged so that the magnetizing direction is aligned with the direction of the diameter of the shaft. Magnetoresistance effect (MR) elements 21-24 are arranged around the means 25 along the logitudinal direction of the rotary shaft 1. The magnetic flux from the magnetic field generating means 25 is flowed into the MR elements 21-24 through the rotary shaft 1. Torque change is generated in the rotary shaft 1. Compressive stress is yielded in the directions shown by arrows 2 and 9, and tensile stress is yielded in the directions of 22 and 24. The magnetic flux, which is flowed to the MR elements 21 and 23 and 22and 24 that are arranged in the diagonal directions, is changed owing to the magnetic strain effect. The resistance values of the elements 21 and 23 and the resistance values of 22 and 24 are changed in the reverse directions. The outputs, which are proportional to the compressive and tensile stresses are obtained at a terminal 36 of a differential amplifier 33. Thus, the change in torque of the rotary shaft 1 can be measured by a simple constitution.

Inventors

• 👤 Takao Tsuji
• 👤 隆男 辻
• 👤 Makoto Shimokooriyama
• 👤 下郡山　信
• 👤 Morimi Hashimoto
• 👤 母理美 橋本

Bibliographic Details