A hydrostatic transmission system includes a hydraulic motor and at least one proportional control valve and at least one pump connected to the hydraulic motor to provide fluid to operate the hydraulic motor. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The hydrostatic transmission system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of a flow and a pressure in the hydrostatic transmission system to an operational set point.

A hydraulic arrangement for supplying a consumer or actuator includes a first supply device that has at least one pump with an adjustable delivery volume. The hydraulic arrangement further includes a second supply device that is connected in parallel to the first supply device. The second supply device includes a loadable accumulator and a digitally regulated switching valve arrangement.

A hydraulic arrangement for supplying a consumer or actuator includes a first supply device that has at least one pump with an adjustable delivery volume. The hydraulic arrangement further includes a second supply device that is connected in parallel to the first supply device. The second supply device includes a loadable accumulator and a digitally regulated switching valve arrangement.

A hydrostatic transmission device of a mobile machine having —at least one first motor and at least one second motor, —at least one first dual motor and at least one second dual motor each having first and second elementary motor, —the second elementary motor of the first dual motor is linked with the first motor by a serial duct, —the second elementary motor of the second dual motor is linked with the second motor by a serial duct, —each serial duct has a valve having an opening for passage of the fluid into the serial duct, said valve having a first position in which said opening has a maximum cross-section, and a second position in which said opening has a reduced cross-section, the movement of said valve between these two positions activated a control instruction generated when the machine is travelling on a slope.

A hydrostatic transmission device of a mobile machine having —at least one first motor and at least one second motor, —at least one first dual motor and at least one second dual motor each having first and second elementary motor, —the second elementary motor of the first dual motor is linked with the first motor by a serial duct, —the second elementary motor of the second dual motor is linked with the second motor by a serial duct, —each serial duct has a valve having an opening for passage of the fluid into the serial duct, said valve having a first position in which said opening has a maximum cross-section, and a second position in which said opening has a reduced cross-section, the movement of said valve between these two positions activated a control instruction generated when the machine is travelling on a slope.

A working machine includes a prime mover, a traveling pump driven by power of the prime mover to deliver hydraulic fluid, a traveling motor rotated by the hydraulic fluid delivered from the traveling pump, an operation valve configured to change a pilot pressure of pilot fluid output therefrom to the traveling pump according to operation of an operation member, an actuation valve to be activated according to a control signal so as to change a primary pressure supplied to the operation valve, a controller to perform setting of the control signal to be output to the actuation valve, and a pressure detection device to detect a secondary pressure output from the operation valve. The controller includes a setting change unit to change, based on the primary pressure and the secondary pressure, the setting of the control signal to be output to the actuation valve.

A working machine includes a prime mover, a traveling pump driven by power of the prime mover to deliver hydraulic fluid, a traveling motor rotated by the hydraulic fluid delivered from the traveling pump, an operation valve configured to change a pilot pressure of pilot fluid output therefrom to the traveling pump according to operation of an operation member, an actuation valve to be activated according to a control signal so as to change a primary pressure supplied to the operation valve, a controller to perform setting of the control signal to be output to the actuation valve, and a pressure detection device to detect a secondary pressure output from the operation valve. The controller includes a setting change unit to change, based on the primary pressure and the secondary pressure, the setting of the control signal to be output to the actuation valve.

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 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.

The present disclosure relates to a hydraulic drive system having a hydraulic circuit architecture operable in first and second modes. In a first mode, a main hydraulic pump (22) is used to drive a hydraulic actuator (24) via a closed hydraulic circuit, and a charge pump (42) provides charge flow to the closed hydraulic circuit. In a second mode the main pump set to zero displacement and the charge pump (42) is used to drive the hydraulic actuator (24).