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 power steering system includes a rack housing arranged to receive a longitudinally displaceable rack member. The system also includes an assist cover connected to the rack housing, the rack housing and the assist cover defining a cavity. The system further includes an assist assembly at least partially disposed within the cavity. The assist assembly includes a power pack connected to at least one of the rack housing and the assist cover, the power pack having a power pack shaft extending therefrom. The assist assembly also includes a drive pulley having a drive pulley shaft that extends between the rack housing and the assist cover, the drive pulley shaft and the power pack shaft separate shafts and operatively coupled to each other. The assist assembly further includes a driven pulley disposed about the rack member.

A power steering system for a motorcycle, such as a motorcycle trike. The power steering system includes a piston having a piston rod disposed within a cylinder. A distal end of the piston rod is pivotably coupled to a fork tube of a motorcycle fork. A power source drives the piston rod away from the cylinder and retracts the piston rod within the cylinder. A control switch controls the piston between a neutral position, a first turn position, and a second turn position. The neutral position includes the piston rod partially extended from the cylinder. The first turn position includes the piston rod extending further from the cylinder than the neutral position. The second turn position includes the piston rod retracted further within the cylinder than the neutral position.

A power steering system for a motorcycle, such as a motorcycle trike. The power steering system includes a piston having a piston rod disposed within a cylinder. A distal end of the piston rod is pivotably coupled to a fork tube of a motorcycle fork. A power source drives the piston rod away from the cylinder and retracts the piston rod within the cylinder. A control switch controls the piston between a neutral position, a first turn position, and a second turn position. The neutral position includes the piston rod partially extended from the cylinder. The first turn position includes the piston rod extending further from the cylinder than the neutral position. The second turn position includes the piston rod retracted further within the cylinder than the neutral position.

A hydraulic system includes a first electric machine connected to a first hydraulic machine and a second electric machine connected to a second hydraulic machine. An output side of the second hydraulic machine is connected to an input side of the first hydraulic machine. A hydraulic consumer is hydraulically coupled to an output side of the first hydraulic machine via a supply line and is powered by the first hydraulic machine. A return line hydraulically couples the hydraulic consumer to an input side of the first hydraulic machine. The second hydraulic machine provides a flow of hydraulic fluid to the input side of the first hydraulic machine if a requested flow from the first hydraulic machine exceeds a flow of the return line and recuperates energy if the requested flow from the first hydraulic machine is lower than the flow of the return line.

Method for controlling a hydraulic system for a working machine, the system including a first electric machine connected to a first hydraulic machine the first hydraulic machine including an input side and an output side a second electric machine connected to a second hydraulic machine the second hydraulic machine including a high-pressure side and a low-pressure side the high-pressure side connected to the input side; a hydraulic consumer coupled to the output side via a supply line and configured to be powered by the first hydraulic machine; a first return line hydraulically coupling the hydraulic consumer to the input side and to the high-pressure side; wherein the method includes detecting a return flow from the hydraulic consumer through the first return line; and controlling the second hydraulic machine to maintain a pressure in the first return line at a pressure level higher than a predetermined minimum pressure level.

A hydraulic steering arrangement (1) is described comprising a supply port arrangement (P, T) having a pressure port (P) and a tank port (T), a working port arrangement having two working ports (L, R), a main flow path (2) having a main orifice (A.sub.1), at least one further orifice (A.sub.2, A.sub.3, A.sub.4) downstream the main orifice (A.sub.1), and a measuring motor (3), the main flow path (2) being arranged between the pressure port (P) and the working port arrangement (L, R), a return flow path (4) arranged between the working port arrangement (L, R) and the tank port (T), an amplification flow path (6) having an amplification orifice (A.sub.U) and being arranged between the pressure port (P) and the working port arrangement (L, R), and an adjustable pressure source (9) connected to the pressure port (P) and having a load sensing port (18), wherein a main drain orifice (A.sub.md) is connected between the main flow path (2) downstream the main orifice (A.sub.1) and the return flow path (4). It should be possible to operate such a steering arrangement with a dynamic flow. To this end a flow divider (19) connects the load sensing port (18) with the main flow path (2) downstream the main orifice (A.sub.1) and the amplification flow path (6) downstream the amplification orifice (A.sub.U).

A utility vehicle such as a loader includes a drive control system that includes an electronic controller and a manually actuated drive command device, such as one or more joysticks. The electronic controller is configured to control the drive control system to supply propulsive power at a predetermined output that is lower than that which is commanded by the drive command device for so long as an output of the drive control system is beneath a designated threshold, maintaining vehicle speed lower than a commanded vehicle speed. The electronic controller is further configured to control the drive control system to ramp up the propulsive power supply toward that which is commanded by the drive command device when the output of the drive control system is above the designated threshold, causing the vehicle speed to approach a commanded vehicle speed. The vehicle may include a EH drive system such as a hydrostatic drive system.

A milling machine includes an engine that generates output power and a rotor that receives the output power from the engine. The milling machine further includes a drivetrain coupled with the engine and the rotor for transmitting the output power to the rotor based on a desired output of the rotor. The drivetrain includes a transmission system operatively coupled with the engine for varying an output of the rotor without altering a load on the engine. The transmission system includes a hydrostatic arrangement operatively coupled with the engine. The transmission system also includes a mechanical arrangement coupled with the engine and the rotor arrangement. The drivetrain also includes a power transmitting arrangement coupled with the transmission system. The drivetrain further includes a gearbox coupled to the power transmitting arrangement and the rotor, such that the power transmitting arrangement is disposed between the transmission system and the gearbox.

An electronic control unit (ECU) may receive, from an autonomous vehicle controller, an instruction to set a hydraulic steering actuator, of a vehicle, to a particular machine steering angle setting. The ECU may provide, to a steering controller torque device, a current to set a steering controller, of the vehicle, to a particular steering controller angle that corresponds to the particular machine steering angle setting. The ECU may provide, to a hydraulic control system, a current to set the hydraulic steering actuator to the particular machine steering angle setting.