The present invention relates to a power-assisted steering apparatus for turning the steerable wheels of a vehicle.
A known power-assisted steering apparatus includes a pinion gear, a valve sleeve, and a torsion bar. The pinion gear includes a recessed end for receiving an end of the torsion bar. The end of the torsion bar includes a spline for fixing the end of the torsion bar relative to the pinion gear. A pin connects the valve sleeve to the pinion gear. Care must be taken when assembling the torsion bar, the valve sleeve, and the pinion gear.
The present invention is a power-assisted steering apparatus for turning steerable wheels of a vehicle. The apparatus comprises a rack bar that is connectable with the steerable wheels of the vehicle. Linear movement of the rack bar turns the steerable wheels. The apparatus also includes a hydraulic motor for, when actuated, moving the rack bar linearly and a one-piece monolithic component. The one-piece monolithic component has a pinion gear portion for meshingly engaging the rack bar, a valve sleeve portion for cooperating with a valve core for actuating the hydraulic motor, and a torsion bar portion for connection with the valve core and twisting in response to rotation of the valve core relative to the valve sleeve portion to actuate the hydraulic motor.