Types and working of Power Steering

There are 2 types of power steering currently in use. These are integral and linkage booster types. Both are operated by hydraulic pressure produced by an engine driven pump to assist in turning the steering mechanism. The integral power steering is explained below :

Integral Power Steering : figure shows the integral power steering when the vehicle moves in the straight head position. the oil pump is belt driven from the engine crankshaft pulley. It consists of a solid cylinder with 2 grooves cut called valve spool which slides within the valve housing. The housing has three internal grooves is connected to the pump and the other are connected to the reservoir.

 

 

The two additional opening are connected to the two sides of the cylinder fitted with piston. When the valve spool is in the position as shown is figure , the pump delivers the oil in the central part of the housing which flows back to the reservoir by the passage shown by the arrows. In this position, there is no oil pressure in the cylinder and there is no tendency for the position to slide in any direction. There is no steering action and the vehicle moves in the straight-head position.

Figure 2nd shows that when the valve spool is moved towards right side, the direct return supply from the pump to the reservoir is closed. The oil flows into the cylinder by the right side passage and pushes the piston to the left side as shown in the figure. The oil on the left side of the piston flows back to the reservoir through the valve housing under this position. The left side outward movement of the piston rod turns towards left side of the road, the vehicle can be turned to the right side by reversing the steering operation.