TORQUE SENSOR, ELECTRIC POWER STEERING DEVICE, METHOD OF PRODUCING CLAW POLE, AND METHOD OF PRODUCING TORQUE SENSOR

摘要

A torque sensor and an electric power steering device that are reduced in size and have significantly improved material efficiency. The torque sensor has first and second shafts coaxially connected together through a connection shaft, a ring-shaped permanent magnet fixed to the second shaft and circumferentially magnetized with multiple poles, a sensor yoke fixed to the first shaft and forming a magnetic circuit together with the permanent magnet, a magnetism collecting yoke placed on the other side, in the axial direction, of the sensor yoke from the permanent magnet and forming a magnetic circuit together with the permanent magnet and the sensor yoke, and a magnetic flux sensor for sensing magnetic flux induced by the sensor yoke and the magnetism collecting yoke. The torque sensor senses, based on an output of the magnetic flux sensor, torque applied to either of the first and second shafts.The sensor yoke is constructed from claw poles arranged on the same or substantially the same plane, and at least some of the claw poles are formed separated from each other.