Motor-driven power steering unit

摘要

A motor-driven power steering unit which can easily be added to an automobile. The motor-driven power steering unit includes a case fixed to the automobile body. A first shaft rotatably is supported in the case and has one end connected to a first lever for being operatively coupled to the steering wheel. A second shaft is rotatably supported in the case coaxially with the first shaft and has one end connected to a second lever for being coupled to the tie rods. A torsion bar is interposed between the first and second shafts and interconnects the first and second shafts. The power steering unit also includes a torque detecting mechanism interposed between the first and second shafts for detecting the steering torque applied from the steering wheel to the first shaft to generate a signal indicative of the detected torque. A motor is disposed in the casing for applying an assistive torque to the second shaft a power supply energizes the motor. A control circuit is responsive to the signal from the torque detecting mechanism for controlling the torque generated by the motor.