A method (300) and control arrangement (210) for controlling a vehicle (100) to freewheel with engine off. The vehicle (100) has an engine (260) for propelling the vehicle (100) and a hydraulic power steering system (400). The hydraulic power steering system (400) comprises a primary power steering pump (270a) arranged to be driven by the engine (260) and a secondary power steering pump (270b). The method (300) includes: determining (301) when to start freewheeling the vehicle (100) with its engine off; and prior to starting the freewheeling of the vehicle (100) with engine off, determining (302) to start the secondary power steering pump (270b).

A steering system for a trailing axle of a motor vehicle includes an electric motor, a hydraulic pump, a first valve, and a working cylinder. The electric motor is configured to drive the hydraulic pump. The working cylinder has a central bore and a piston positioned in the working cylinder. The first valve is fluidically connected to the pump such that the first valve is configured to block flow between the central bore and the pump in response to pressure generated by the pump, and to release the flow in response to a non-pressurized state of the pump in order to divert hydraulic fluid from the working cylinder through the central bore via an adhesion-driven movement of the piston into a central position in the central bore. A method includes operating a steering system for a trailing axle of a motor vehicle of this type.

The present technology describes systems and methods for varying a pump speed of an electric truck. In examples, vehicle efficiency losses may be reduced by varying the speed of a hydraulic pump associated with a power steering gear. An electronic control unit (ECU) may receive a set of steering information from a torque overlay system (TOS). Based on the set of steering information, a power may be provided to a variable pump motor. The power provided to the variable pump motor may correspond with a speed of a hydraulic pump associated with a power steering gear of the vehicle. As new or additional steering information is received from the TOS, the ECU may adjust the power provided to the variable pump motor.

A soil processing machine, in particular a soil compactor, includes a hydraulic steering system with at least one steering element actuated with pressurized fluid and an electrohydraulic pressurized fluid source with at least one steering pressurized fluid pump that can be driven by at least one electric motor for feeding pressurized fluid into a steering pressurized fluid circuit.

A hydraulic system for a working machine includes a first electric machine connected to a first hydraulic machine; a second electric machine connected to a second hydraulic machine, an output side of the second hydraulic machine being connected to an input side of the first hydraulic machine; at least one hydraulic consumer hydraulically coupled to an output side of the first hydraulic machine via a supply line and configured to be powered by the first hydraulic machine; and a valve arrangement arranged between the hydraulic consumer and the first and second hydraulic machines, wherein the valve arrangement is configured to control a return flow of hydraulic fluid from the hydraulic consumer to either the input side of the first hydraulic machine or an input side of the second hydraulic machine based on a requested output pressure from the first hydraulic machine.

A hydraulic auxiliary axle steering control system is provided. In detail, there is provided a hydraulic auxiliary axle steering control system that can perform quick, precise, and safe control by changing an auxiliary axle steering control angle in accordance with a vehicle speed to problems with instability of driving, wear of tires, and a turning radius when a vehicle is driven at a low speed.

The present invention discloses a drive-by-wire electro-hydraulic steering system based on a double-winding motor and a hybrid control method. The steering system includes a steering wheel (1), a steering column assembly, a road sense assembly, an electro-hydraulic power-assisted module, a double-winding motor power-assisted module (28), a steering control unit, an electromagnetic clutch (8), a steering tie rod (17), a steering trapezoid (13) and steering wheels (12). The steering system can be switched among various steering work modes according to work conditions of a vehicle, meets steering requirements under various work conditions, uses a work mode that two sets of windings of the double-winding motor work at the same time, and has a motor winding redundancy function. When one set of windings fails, the other set of windings can drive the motor to provide power-assisted torque.

The invention relates to a steering system for at least one trailing or leading axle of a vehicle, comprising: a steering angle sensor for measuring a steering angle of wheels of a leading axle of the vehicle; a driving speed sensor for measuring a driving speed of the vehicle; an electric motor (1.2) that drives a hydraulic pump (2); a working cylinder (11) for steering the wheels of the trailing axle, which is joined to the hydraulic pump (2); a control device (1.1) which determines a trailing angle of wheels on the trailing axle of the vehicle, using the data of the steering angle sensor and the driving speed sensor, and which controls the electric motor in a corresponding manner, wherein the working cylinder (11) has a centre position borehole (1.3) via which hydraulic fluid can be emitted from the working cylinder (11), and a piston seals the centre position borehole (11.3) in the straight position of the wheels of the trailing axle, wherein the working cylinder (11) is connected to return valves (10 and 10.1), via which hydraulic fluid can flow back into a tank (6), wherein the centre position borehole (11.3) of the working cylinder (11) is connected to a centre position valve (12), via which hydraulic fluid can flow back into a tank (6), and wherein the return valves (10 and 10.1) and the centre position valve (12) are in the form of a poppet valve.

An electrohydraulic steer-by-wire steering system has an operator interface for specifying a turning angle, which is associated with a sensor for the acquisition of a position or movement of the operator interface. An electronic control device is connected to a first electrohydraulic circuit and to a second electrohydraulic circuit and set up in order to actuate the two electrohydraulic circuits as a function of a signal from the sensor. The system further includes a steering actuator for adjusting the turning angle of a steerable wheel. The steering actuator has two chambers each of which is connected simultaneously to the two electrohydraulic circuits.

The present technology describes systems and methods for varying a pump speed of an electric truck. In examples, vehicle efficiency losses may be reduced by varying the speed of a hydraulic pump associated with a power steering gear. An electronic control unit (ECU) may receive a set of steering information from a torque overlay system (TOS). Based on the set of steering information, a power may be provided to a variable pump motor. The power provided to the variable pump motor may correspond with a speed of a hydraulic pump associated with a power steering gear of the vehicle. As new or additional steering information is received from the TOS, the ECU may adjust the power provided to the variable pump motor.