Power Steering Pumps for Commercial Vehicle

Steering operating principle
During steering, the driver transmits the steering torque to the input shaft of the steering gear through the steering wheel. The input shaft and the steering screw are connected together through a torsion bar. The steering screw is connected to the wheel through a steering nut (rack piston), steering rocker shaft, steering rocker arm, and steering straight link. The steering torque from the input shaft is transmitted to the screw through a torsion bar. Due to the above circular ball mechanism, the screw attempts to make the rack piston move axially along the cylinder bore, but the ground resistance from the wheel restricts the axial movement of the rack piston through the rocker arm system. Therefore, the torsion bar is twisted, and the relative position of the oil groove on the input shaft and the oil groove on the valve sleeve changes - that is, the control valve functions, The high-pressure oil is directed to the designated oil cylinder, namely, the upper or lower oil cylinder, which generates a hydraulic force on the corresponding rack piston end face, and pushes the rack piston to move axially, causing the rocker shaft to rotate, achieving vehicle steering.

Critical parameters:

Dismantling Process

1. Fix the Power Steering Pump, use a torque wrench to loosen the relief valve plug, manually open the relief valve to take out the valve spring with snap ring pliers.

2. Place the pump body on the press machine. Use the press machine to gently press the rear cover of the pump body and fix the position. Use a self-made screwdriver to remove the back-up ring. Remove the Steering Pump from the press machine and turn the pump cover down, tap the rear cover. Remove the rear cover and the spring with the action of the spring under the rear cover and remove the internal components of the steering pump, including the pressure plate, side plate, stator, rotor and vanes.

For more details, see videos.