Power steering device

A power steering device, comprising:

• an input shaft configured to be rotated by a steering operation on a steering wheel;
• an output shaft connected to the input shaft via a torsion bar;
• a power cylinder including a pair of hydraulic chambers partitioned by a piston, and configured to generate a steering assist force for a steered wheel;
• a conversion mechanism configured to convert rotation of the output shaft into an axial motion of the piston;
• a transmission mechanism configured to transmit the axial motion of the piston to the steered wheel;
• a pump device configured to be driven through control by a first electric motor and configured to discharge working fluid;
• a rotary valve configured to selectively supply the working fluid supplied from the pump device to the pair of hydraulic chambers of the power cylinder in accordance with relative rotation between the input shaft and the output shaft;
• a hollow second electric motor provided so as to surround at least a part in an axial direction of the input shaft and configured to control the rotation of the input shaft;
• a control device including a microcomputer configured to control driving of the hollow second electric motor;
• a first motor revolution number signal reception part installed in the control device and configured to receive a revolution number signal of the first electric motor;
• and
• a second electric motor control part installed in the control device and configured to output a control signal for controlling driving of the second electric motor based on the revolution number signal of the first electric motor.