844 Hydraulics Course Notes — Page 88

- Yo fulfil this function, the system just described is used. When the driver lets go of the steering wheel, the torque which was acting against his turning motion then acts on the control shaft. This torque operates the power assistance, i.e. it replaces the effort of the driver on the steering wheel by a mechanical force acting directly on the control shaft, and brings the steering back to the straight ahead position where the torque is no longer exerted.