A method is provided for actuating an electric motor of a pump device of a steering device, having a step of reading the current rotational angle of the electric motor of the pump device and a correction value which represents a relationship between an output pressure of the pump device and/or the rotational speed of the electric motor of the pump device on the basis of the rotational angle of the electric motor, and a step of outputting an actuation signal to the electric motor using the correction value.

A pump apparatus for an electrohydraulic power steering mechanism for a vehicle includes a hydraulic pump, a working line, a pressure generator, a first control line, a preliminary pressure line, a compensation tank, a shut-off valve having a control inlet, and a second control line. The hydraulic pump is designed to pump a hydraulic oil out of a pump chamber to a pump outlet of the hydraulic pump. The pressure generator has a pressure generation inlet and a pressure generation outlet, and the pressure generator is designed to generate, using an inlet pressure present at the pressure generation inlet, an outlet pressure which can be provided at the pressure generation outlet and is lower than the inlet pressure. As a result, a preliminary pressure can be generated in the pump chamber.

A valve device for a steering device of a vehicle includes a pump device with a pump for pumping a working medium to a first discharge connection or a second discharge connection of the pump device and a motor for driving the pump. The valve device further has a valve and/or a storage container, wherein the valve and/or the storage container are switched between the first discharge connection of the pump device and the second discharge connection of the pump device.

A pump device for a steering device of a vehicle includes a pump for pumping a working medium to a first outlet connection or alternatively to a second outlet connection, an electric motor for driving the pump, and a housing, through which the first outlet connection and the second outlet connection are guided. The housing is arranged about the pump and the electric motor.

An electrohydraulic power steering device for a vehicle includes a hydraulic pump, a drive, a first working line, a second working line, and a heat exchanger. The hydraulic pump is designed, in a first rotation direction, to pump a hydraulic oil to a first pump output of the hydraulic pump and, in a second rotation direction, to pump said oil to a second pump output of the hydraulic pump. The drive is coupled to the hydraulic pump and is designed to drive the hydraulic pump selectively in the first rotation direction or second rotation direction. The first working line is shaped to connect the first pump output fluidically to a first working chamber, the first working chamber being suitable for moving a piston, which is couplable to a steering bar of a steering system, in a first direction. The heat exchanger is designed to transfer heat that is generated during operation of the drive to at least one of the working lines in order to heat the hydraulic oil flowing through the working line.

A hydraulic system, a mobile mining machine and to a method of controlling a hydraulic actuator is provided. The hydraulic system includes two hydraulic pumps (P1, P2) for generating hydraulic power for a hydraulic actuator. The pumps are powered by means of a common electric motor. Operation of the actuator is controlled by controlling speed and direction of the motor, whereby hydraulic lines (19a, 19b) may be without actively controlled control valves.

A method for turning steerable wheels of a vehicle includes supplying fluid under pressure to a hydraulic power steering motor with a pump driven by an engine of the vehicle to turn the steerable wheels during operation of the engine. It is determined if the engine of the vehicle is shut down. An electric motor applies power assist to turn the steerable wheels when the engine is shut down. An apparatus for turning steerable vehicle wheels includes a hydraulic power steering motor assembly connected with the steerable vehicle wheels. A pump connected with the power steering motor assembly is driven by an engine of the vehicle to supply fluid under pressure to the power steering motor assembly during operation of the engine. An electric motor connected with the steerable vehicle wheels applies power assist to turn the steerable vehicle wheels. A controller operates the electric motor to apply the power assist when the engine is shut down.

A vehicle steering assist system, including an engine pump, a flow-rate restricting mechanism, a motor pump, a motor-pump controller, and a steering-force assist device, wherein the steering assist system is configured to restrict an engine-pump ejection flow rate to be lower than a required receiving flow rate to be received by the assist device when the engine pump is operated by being driven by an engine rotating at an idling speed, the engine-pump ejection flow rate being a flow rate of a working fluid ejected from the engine pump to the assist device via the restricting mechanism, and wherein the motor-pump controller is configured to control a motor-pump ejection flow rate such that an insufficient flow rate of the working fluid is covered by the motor-pump ejection flow rate, the insufficient flow rate being a shortage in the required receiving flow rate not covered by the engine-pump ejection flow rate.

A steering assist system for a hybrid vehicle capable of being driven by both of an engine and a drive motor, including a first assist portion and a second assist portion configured to assist a steering force respectively utilizing the engine and an electric motor each as a drive source, wherein the steering force is assisted only by the second assist portion in a motor-driven state in which the vehicle is driven only by the drive motor, and wherein the steering assist system is configured to, upon occurrence of a failure of the second assist portion in the motor-driven state, drive the engine, execute assist switching from an assist by the second assist portion to an assist by the first assist portion, and gradually increase, in the assist switching, an assist force by the first assist portion up to a set assist force when the vehicle is being steered.

This invention is a steering system for a trailing or leading axle of a vehicle including a steering angle sensor, a driving speed sensor, an electric motor that drives a hydraulic pump, a working cylinder for steering wheels of the axle, which is joined to the hydraulic pump, a control device which determines a trailing angle of the wheels and which controls the electric motor, wherein the working cylinder has a center position borehole via which hydraulic fluid is emitted, and a piston seals the center position borehole in the straight position of the wheels, wherein the working cylinder is connected to return valves, via which hydraulic fluid can flow back into a tank, wherein the center position borehole is connected to a center position valve, via which hydraulic fluid can flow back into a tank, and wherein the return valves and the center position valve are poppet valves.