Function

POWER STEERING PUMP
Power steering assists the driver during steering and must therefore apply a large part of the steering moment.

Any power steering requires an energy source for this.

The hydraulic energy is produced by a power steering pump which is driven by the engine.

The power steering pump is designed as a vane-type pump.

It meets the requirements which are placed on a power steering system in the vehicle particularly well.

Higher volumetric efficiency at idle speed, low output at high speeds, low noise and low pulsation delivery as well as producing higher pressures are the most important points which characterize the vane-type pump.

The flow rate of the vane-type pump is designed so that full power steering assistance is achieved at engine idle speed.

The flow rate is controlled via the flow rate control valve.

The max. pump pressure is controlled via the pressure limiting valve which is integrated in the flow rate control valve.

STEERING GEAR
The steering gear is designed as a recirculating ball steering system.

The servo section in the steering gear comprises a power piston, which is located as a modular design around the mechanical transmission part in a cylindrical housing and represents the connection to the steering wheel and the wheels.

The oil circuit between the power steering pump and steering gear is created by a high pressure and return hose. When the engine is running, oil is delivered through the oil circuit via circulation pressure.

The oil pressure required for steering assistance is supplied by a servo valve spool which throttles the oil flow rate and at the same time directs the pressure oil to the correct side of the power piston.

The other side of the power piston is simultaneously connected in a depressurized condition to the power steering pump reservoir via the spool valve.