Steering unit

The central control element of hydrostatic steering is called a steering unit , also known as a servostat or orbitrol .

function

In contrast to conventional power steering , these steering systems have no mechanical connection between the steering wheel and the steered wheels. The steering unit passes the by a hydraulic pump supported volume flow rate of the movement on the steering wheel according to the working spaces of a hydraulic cylinder which actuates the axle steering. The steering angle and the steering direction are important. A priority valve is used to ensure that the steering works under all circumstances, provided that the hydraulic pump also supplies other systems (e.g. the lifting gear on forklifts ) .

Areas of application

Hydrostatic steering systems and thus steering units are used today primarily in heavy commercial vehicles, such as. E.g .: forklifts and tractors . Since the steering would fail if the hydraulic pump failed, modern steering units usually have an emergency steering function , the control element then acting as a manually controlled hydraulic pump. In order to reduce the steering force to be applied, the delivery volume is reduced in some of these systems, which causes a change in the ratio .