Fluid Pump And Reservoir Tank: Notes
The fluid pump is a vane type driven by the engine via belt.
The reservoir tank is mounted on the vehicle body.
The fluid pump incorporates the flow control valve and relief valve, each performing the following functions:
- The flow control valve regulates the flow rate of discharged fluid to a constant level irrespective of the engine speed.
- The relief valve protects the system from excessively high pressures that may occur, for example, when the steering wheel is turned all the way.
- To stabilize the fluid temperature, an oil cooler is installed between the reservoir tank and gearbox.
- The fluid pump is belt-driven by the engine. The fluid flow is controlled according to the engine speed so that an adequate steering resistance is given during high-speed operation.
The fluid pump is a variable capacity type vane pump whose delivery rate per rotation decreases as the engine speed increases. The pump is integral with a pump control valve and relief valve.
- The vane pump consists of a rotor, a cam ring, and 11 vanes.
When the rotor rotates, the vane in each slot of the rotor is moved out by centrifugal force in radial directions and pressed against the cam ring. The fluid from the suction port is confined in chambers formed between two adjacent vanes and carried to the discharge port. Since the cam ring is movable in relation to the rotor, the volume of each chamber is variable. This enables the delivery rate per rotation of the pump to be changed.