Servo-assisted steering system for motor vechicles

A servo assisted steering system for motor vehicles, comprising a steering gear housing (1) a steering wheel shaft (2) connected through a torque rod (2A) to a steering wheel a flow control rotary slide valve (6, 7, 8) connected to input member worm gear shaft (4) of a steering gear (5) including a servo motor piston (15) operatively connected to a servo pump (11), so that rotation of a steering wheel with respect to that input member effects flow of oil under pressure from said servo pump via said rotary valve to at least one chamber (13, 14), a power take up shaft (20) at the end of said torque rod, an electric motor (21) in operational connection with the rotary slide (7) of said rotary slide valve and said steering gear, further including a motor control means (23) including a sensor (22) responsive to steering wheel rotation, said control means operates said electric motor (21) to generate a torque opposite to that of steering wheel torque on said torque rod (2A) to counter rotate said rotary slide (7) and upon release of the steering wheel effects a move of said servo motor piston towards neutral position.