A sickle knife drive for an agricultural vehicle generally includes a first pump, a first motor, a second motor and a drive manifold having a plurality of connections used for connecting to other devices of the sickle knife drive and/or to devices outside of the sickle knife drive. Operation of the first pump in a forward direction causes the first motor to drive a sickle knife gearbox to cut a crop. During the forward direction, the second motor provides cooling to the fluid circuit. When the first pump direction is reversed, the agricultural vehicle supplements a fluid flow to the fluid circuit to clear any jammed crop from the sickle knives.

A soil processing machine includes a hydraulic drive system including an electrohydraulic pressurized fluid source with at least one electric motor and at least one hydraulic drive pump, a hydraulic drive circuit fed with pressurized fluid by the at least one hydraulic drive pump, at least one hydraulic drive motor fed with pressurized fluid from the hydraulic drive circuit, and a discharge valve assembly for discharging fluid from the hydraulic drive circuit to a fluid reservoir. The hydraulic drive system is designed to operate the discharge valve assembly as a function of at least one of the following parameters: a temperature of the fluid in the hydraulic drive circuit, an ambient temperature, a viscosity of the fluid in the hydraulic drive circuit, a degree of contamination of the fluid in the hydraulic drive circuit, a period of time since the last start-up of the hydraulic drive system, a period of time since the last fluid was discharged from the hydraulic drive circuit.

Methods and systems for a transmission are provided herein. In one example, a hydraulic system is provided that includes a boost pump, a relief valve in fluidic communication with the boost pump and a reservoir, and a plurality of control valves in fluidic communication with the boost pump, positioned downstream of the relief valve, and in fluidic communication with a plurality of hydraulic devices. The hydraulic system further includes a controller designed to actively adjust a position of the relief valve based on an aggregate hydraulic pressure demand of the plurality of hydraulic devices to alter a boost pressure of a hydraulic fluid supplied to the plurality of control valves.

The invention concerns a hydrostatic drive with a closed hydraulic fluid circuit comprising a hydraulic motor and a variable displacement pump. A feed pump feeds hydraulic fluid under pressure. A control device regulates pressure to a double-sided servo control unit comprising a control piston in a double-sided control cylinder so that the control piston can open a feed line for hydraulic fluid to one side while opening a discharge line on the other. The control device comprises an actuator at the cylinder by means of which force can be exerted onto the piston. A preload element exerts force onto the piston. The pressure generated by the variable displacement pump returns via a return line such that force is exerted in the direction of the piston, if inactive, the piston is maintained by the preload element and the pressure of the variable displacement pump.

The present invention relates to a hydraulic system with a feed pump for feeding hydraulic fluid, wherein the feed pump is driven by a hydraulic drive motor. The invention furthermore comprises a method for feeding hydraulic fluid into a hydraulic system via a feed pump, wherein the feed pump is driven by a hydraulic drive motor.

The present invention relates to a hydraulic system with a feed pump for feeding hydraulic fluid, wherein the feed pump is driven by a hydraulic drive motor. The invention furthermore comprises a method for feeding hydraulic fluid into a hydraulic system via a feed pump, wherein the feed pump is driven by a hydraulic drive motor.

A booster device for a hydraulic circuit comprising a high-pressure circuit (12) and a low-pressure circuit (16) connected to a system generating the high pressure and to receivers, said booster device maintaining a minimum pressure in the low-pressure part, characterized in that it comprises a hydraulic motor (30) of which the inlet is connected to the high-pressure circuit (12) and the outlet to the low-pressure circuit (16), which drives a booster pump (20) sucking the fluid from a reservoir (24), in order to discharge it into this low-pressure circuit.

A booster device for a hydraulic circuit comprising a high-pressure circuit (12) and a low-pressure circuit (16) connected to a system generating the high pressure and to receivers, said booster device maintaining a minimum pressure in the low-pressure part, characterized in that it comprises a hydraulic motor (30) of which the inlet is connected to the high-pressure circuit (12) and the outlet to the low-pressure circuit (16), which drives a booster pump (20) sucking the fluid from a reservoir (24), in order to discharge it into this low-pressure circuit.

A travel control device is provided with hydraulic pumps of a variable capacity type that are driven by an engine; hydraulic motors that are driven by discharged oil from the hydraulic pumps; traveling devices that are rotation-driven by the hydraulic motors; a travel operation lever that is operated so as to instruct a traveling operation; a first control valve for generating a charged hydraulic pressure by adjusting the discharged oil from a charge pump and a second control valve for generating a capacity control hydraulic pressure in accordance with the operation of the travel operation lever. The first control valve is designed to pressure-adjust and generate a charged hydraulic pressure in accordance with the rotation speed of the engine, and the hydraulic pump is subjected to a variable capacity control process by a capacity control hydraulic pressure that is pressure-adjusted and generated by the second control valve.

A transaxle for use as a drive apparatus of a vehicle is provided. The transaxle includes a main housing joined to a gear housing to enclose a transmission and a reduction gear set. The transmission includes a pump assembly and a motor assembly arranged in a parallel configuration on one side of a center section. A charge pump is contained within a pocket on an opposing side of the center section. A charge pump cover assembly secures the charge pump in the pocket and has a charge relief assembly that extends into a void volume defined by a ring gear of the gear reduction set. The gear reduction set drives an axle extending from the gear housing.