Abstract: A power steering device has a hydraulic actuator that generates steering assistance power by using hydraulic fluid fed from a pump driven by a brushless electric motor. The device controls the motor's rotation speed to have a preset steering assistance speed in a steering assistance mode, and a preset standby speed in a steering assistance release mode. The motor rotation speed is set to the steering assistance speed after being set to a maximum speed that exceeds the steering assistance speed in the steering assistance mode.

Abstract: A torque sensor which includes two cylinders fixed to two shafts connected with each other through a torsion bar. The magnetic coupling state of the two cylinders is made variable corresponding to relative rotations of the two shafts. The magnetic coupling state thereof is detected by a coil impedance, which is indicative of a torque acting on the shafts. The two cylinders form at the opposite end edges thereof teeth provided with cutouts disposed circumferentially of the cylinders and are opposite to each other at portions of about half a width of each tooth. The two shafts are regulated by rotation so as to not put the teeth of the cylinders completely opposite or non-opposite to each other.

Abstract: A torque sensor which includes two cylinders fixed to two shafts connected with each other through a torsion bar. The magnetic coupling state of the two cylinders is made variable corresponding to relative rotations of the two shafts. The magnetic coupling state thereof is detected, which is indicative of a torque acting on the shafts. The two cylinders form at the opposite end edges thereof teeth provided with cutouts disposed circumferentially of the cylinders and are opposite to each other at portions of about half a width of each tooth. The two shafts are regulated by rotation so as to not put the teeth of the cylinders completely opposite or non-opposite to each other. This enlarges a rate of change in the magnetic coupling state, detecting the torque with high sensitivity, and reducing a lateral difference in the output.