STEERING (Description): DESCRIPTION AND OPERATION (page 9 of 11)

STEERING

DESCRIPTION AND OPERATION

57-13

The internal 'cam' shape of the pump housing causes the rollers to move closer together as the pump rotor rotates 
towards the outlet port. The reduced volume of the chamber between the roller vanes causes the fluid to become 
pressurised. When the chamber is opened to the outlet port of the pump the fluid escapes at high pressure. The roller 
vanes continue turning and go past the outlet port, closing off the chamber between the two roller vanes.

As rotation continues the inlet sequence begins again. The inlet and pressurisation/outlet sequences continue as the 
pump rotates, and is repeated between each two roller vanes. The pump is a positive displacement type and the 
potential pump output increases with engine (drive pulley) speed. The pressure relief and flow control valve regulates 
flow/pressure by diverting fluid back to the pump inlet through internal recirculation passages in the pump body.