Power Steering Gear

The input shaft in the steering gear has a torsion bar which connects the input shaft and the main shaft. As the steering wheel is turned, the input shaft turns, moving the spool valve according to how much the steering wheel is turned. This valve movement allows fluid to flow so that hydraulic pressure is applied to the piston, providing assistance to the steering effort.

When the steering wheel is in the straight-ahead position, the spool valve does not operate and the power steering fluid flows from the power steering pump through the short-circuit back to the oil tank.

When the steering wheel is turned to the right, the input shaft pushes the spool valve to the right, allowing hydraulic pressure to be applied to the right side of the cylinder.

When the steering wheel is turned the left, the input shaft pushes the spool valve to the left to allow the hydraulic pressure to be applied to the left side of the cylinder.