The invention relates to a power steering system for a working machine, said power steering system comprising at least one steering cylinder comprising two compartments separated by a piston, a tank, a steering unit comprising a steering valve and a metering device, for supplying one compartment of the steering cylinder with a metered liquid flow, a hydraulic pump for pumping liquid from the tank to the steering unit through a supply line (SL), a return line (RL) through which the liquid flows back to the tank, a recirculation line connecting the RL to the SL, a check valve being arranged on said recirculation line to prevent liquid from flowing from the SL to the RL, two control lines, respectively connecting the steering unit to the two compartments and a liquid accumulator connected through a branch to the RL. A relief valve is arranged on the RL between the tank and an accumulator connection point.

The invention relates to a power steering system for a working machine, said power steering system comprising at least one steering cylinder comprising two compartments separated by a piston, a tank, a steering unit comprising a steering valve and a metering device, for supplying one compartment of the steering cylinder with a metered liquid flow, a hydraulic pump for pumping liquid from the tank to the steering unit through a supply line (SL), a return line (RL) through which the liquid flows back to the tank, a recirculation line connecting the RL to the SL, a check valve being arranged on said recirculation line to prevent liquid from flowing from the SL to the RL, two control lines, respectively connecting the steering unit to the two compartments and a liquid accumulator connected through a branch to the RL. A relief valve is arranged on the RL between the tank and an accumulator connection point.

A variable ratio hydraulic steering device with two or more orbit displacers ensures steering with low actuating forces even in the event of a total or partial failure of the oil flow supply. In the event of a total or partial failure of the oil flow supply, the device is capable of switching from one orbit displacer to another, if necessary, independently of the pressure at the inlet connection of the steering device.

In the event of a malfunction in the supply of hydraulic fluid to the a braking device actuating device a hydraulic system has a manually actuated emergency-operation valve arrangement which is formed in such a way that, after the manual actuation thereof, a fluid connection is created between a steering device actuating device and the a pressure chamber of the braking device actuating device. The emergency-operation valve arrangement has a valve block in which flow paths are formed which can be shut off by means of shut-off screws.

In the event of a malfunction in the supply of hydraulic fluid to the a braking device actuating device a hydraulic system has a manually actuated emergency-operation valve arrangement which is formed in such a way that, after the manual actuation thereof, a fluid connection is created between a steering device actuating device and the a pressure chamber of the braking device actuating device. The emergency-operation valve arrangement has a valve block in which flow paths are formed which can be shut off by means of shut-off screws.

The present disclosure relates to redundant steering system, including a first steering knuckle rotatable with respect to a first steering axis, a first steering cylinder, a first steering rod coupled to the first steering cylinder, a second steering cylinder, and a second steering rod coupled to the second steering cylinder. The first steering rod and the second steering rod are each rotatably coupled to the first steering knuckle at a distance from the first steering axis and at different positions along the first steering axis.

The present disclosure relates to redundant steering system, including a first steering knuckle rotatable with respect to a first steering axis, a first steering cylinder, a first steering rod coupled to the first steering cylinder, a second steering cylinder, and a second steering rod coupled to the second steering cylinder. The first steering rod and the second steering rod are each rotatably coupled to the first steering knuckle at a distance from the first steering axis and at different positions along the first steering axis.

A hydraulic steering device hydraulically connects a steering cylinder to a supply system, wherein the supply system can be operatively connected hydraulically to the steering cylinder via a steering valve in order to configure a main flow connection, and the supply system can be operatively connected hydraulically to the steering cylinder via a flow control valve arrangement in order to configure an auxiliary flow connection which bypasses the main flow direction.

A hydraulic steering device hydraulically connects a steering cylinder to a supply system, wherein the supply system can be operatively connected hydraulically to the steering cylinder via a steering valve in order to configure a main flow connection, and the supply system can be operatively connected hydraulically to the steering cylinder via a flow control valve arrangement in order to configure an auxiliary flow connection which bypasses the main flow direction.

A hydraulic steering arrangement (1) is described comprising a supply port arrangement having a pressure port (P) and tank port (T), a working port arrangement having two working ports (L, R), a steering unit (2) arranged between the supply port arrangement and the working port arrangement and a steering valve (3) arranged between the supply port arrangement and the working port arrangement. Such a steering arrangement should have a safety means. To this end in a manual steering mode the steering valve (3) is connected to the working port arrangement through the steering unit (2).