A work vehicle that includes a hydraulic system. The hydraulic system includes a hydraulic motor that generates rotational power for one or more wheels on the work vehicle. A hydraulic pump couples to the hydraulic motor. The hydraulic pump pumps hydraulic fluid to the hydraulic motor. A hydraulic shift control system controls shifting of the hydraulic system. The hydraulic shift control system includes a controller that controls a hydraulic motor volume of the hydraulic motor and a fluid volume pumped by the hydraulic pump to gradually change a speed of the work vehicle during a shift.

A milling machine may have a frame, first and second ground engagement members connected through respective, vertically adjustable leg columns to a front end of the frame, and third and fourth ground engagement members connected through respective, vertically adjustable leg columns to a rear end of the frame. Each vertically adjustable leg column includes a hydraulic cylinder connecting the frame and the associated ground engagement member. A milling drum is attached to the frame between the front and rear ends. At least one pair of the leg columns connected to the front end of the frame or the leg columns connected to the rear end of the frame includes an accumulator associated with each of the at least one pair of leg columns, a fluid conduit fluidly connecting a bore end of each of the hydraulic cylinders to the associated accumulator, and a control valve disposed in the fluid conduit and configured to control a flow of fluid between the hydraulic cylinders and the associated accumulators.

The invention relates to a compressed-air supply system for operating a pneumatic installation in a pneumatic system of a vehicle, comprising: a compressed-air feed; a compressed-air connection point to the pneumatic installation; a venting connection point to the environment; a pneumatic main line between the compressed-air feed and the compressed-air connection point, which pneumatic main line has an air dryer; a venting valve, which is arranged on the pneumatic main line and is designed as a pilot valve and has a pilot connection point; a compressor having at least one compressor stage; and, in addition to the pneumatic main line, a pilot valve and a pneumatic pilot channel that connects the pilot valve to the pilot connection point of the venting valve. With respect to the compressed-air supply system, according to the invention, a pressure-holding pneumatic reservoir device is connected to the pilot connection point, which reservoir device is designed to provide a control pressure for the pilot connection point, in particular independently of a pressure in the pneumatic main line during venting of the pneumatic system, and the pressure-holding pneumatic reservoir device has at least one separate pilot pressure accumulator, which can be pneumatically connected to the pilot connection point via the control line.

An integrated hybrid energy recovery and storage system for recovering and storing energy from multiple energy sources is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system further includes two or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes two or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.

Passenger restraint systems are provided. The restraint systems can include: a passenger seat supported by a frame; a restraint bar pivotably attached to the frame; and at least one piston operably engaged between the restraint bar and the frame. Restraint system pistons are provided. The pistons can include: a central chamber housing a piston head and rod; a fluid reservoir in fluid communication with the central chamber; and at least one electromechanical valve operable between an open and a closed position. Methods for restraining a passenger within a seat are also provided.

An exemplary method generally includes charging hydraulic fluid into or out of a cavity of an accumulator at a controlled flowrate, detecting movement of a machine component from a first position toward a second position, determining an idle time spanning from a start of the charging to detection of the movement of the machine component, and determining a pre-charge of the accumulator based upon the idle time and a flowrate value of the controlled flowrate.

Some embodiments of the disclosure provide an advance and retreat automatic control method based on hydraulic sensing conversion and an advance and retreat automatic control system based on hydraulic sensing conversion, which includes an automatic advance and retreat device based on hydraulic sensing conversion, a motor, an oil cylinder, and/or an electric generator. When the digging motor encountered an overlarge resistance force, a pressure on the digging motor is instantaneously increased and exceeds a setting pressure value, hydraulic oil enters a hydraulic operated directional valve and pushes a valve rod to make the walking motor is reverse and retreat, an ultrahigh pressure state of the digging motor is released to restore to a normal pressure value to make reciprocated impact, the valve rod of the hydraulic operated directional valve is reset, and the walking motor is forwards rotated for advancing.

A hydraulic block of a slip control system of a hydraulic vehicle brake system includes receptacles for the hydraulic accumulator and receptacles for outlet valves arranged on opposite sides of each other in the hydraulic block. The sides of the hydraulic block, which comprise the receptacles for the outlet valves and the hydraulic accumulators, are connected to one another by bores perpendicular thereto.

The present invention relates to An open center hydraulic system (100), the open center hydraulic system (100) comprising a tank configured to hold hydraulic fluid, a pump configured to provide pressurized hydraulic fluid from the tank, a shunt valve configured to adapt an first opening area between a first input port and a first output port of the shunt valve dependent on a first control signal, wherein the first input port is coupled to the pump and the first output port is coupled to the tank, a first actuator valve coupled to the first input port and configured to adapt a second opening area of the first actuator valve dependent on a second control signal, a hydraulic valve control unit configured to determine a first opening area value and a second opening area value based on user input data and a predetermined relation dependent on the user input data, sending the first control signal, indicative of the first opening area value and sending the second control signal indicative of the second opening area value.

A servohydraulic drive includes a hydrostatic displacement machine, an electric machine that is mechanically speed-coupled with the displacement machine, a hydraulic cylinder that is fluidically connected to the displacement machine via first and second working lines, a hydraulic accumulator, and a supply unit. The displacement machine has a stroke that is adjustable via a hydraulic adjustment device. The cylinder is configured to be activated by reversal of the fluid flow through the displacement machine in opposite directions. The accumulator is preset to a low pressure and is fluidically connected via a valve assembly in each case to the lower pressure working line. The supply unit is configured to supply the adjustment device with pressurized fluid under the necessary pressure for the adjustment regardless of the present pressure in the working lines such that the displacement machine is configured for an active and load pressure-independent adjustment of its stroke volume.