Pic. 5.2. Power steering pump device
All models are equipped with power steering, the performance of which depends on the engine speed.
Power steering pump
Pic. 5.3. Power steering pump flow parameters
The control spool that regulates fluid flow at medium and high pump speeds has been replaced by a flow control valve stem that regulates the area of the orifice.
Low pump speed range (A)
Pic. 5.4. Low pump speed range (A)
The increase in flow is proportional to the increase in pump speed.
Medium speed range, steering not working (B)
Pic. 5.5. Medium speed range, steering not working (B)
As a result of the increase in flow generated by the vane pump, the flow control valve moves to the left and lowers the flow, reducing the orifice area around the conical surface of the stem.
High speed range, steering not working (WITH)
Pic. 5.6. High speed range, steering not working (WITH)
The flow control valve continues to move to the left and reduces flow by reducing the orifice with the cylindrical surface of the stem.
Work under load (under pressure) (D→D’)
Pic. 5.7. Work under load (under pressure) (D→D’)
If the steering gear is operating in the medium to high speed range, increasing pump pressure on the left side of the flow control valve moves the latter to the right, restoring the flow rate.