A hydraulic system for an automatic transmission of a motor vehicle, with which hydraulic cylinders of at least one clutch, and of gear selectors can be actuated, which hydraulic system includes a pressure accumulator for providing an accumulator pressure in the hydraulic system. In at least one clutch path leading from the pressure accumulator to the clutch hydraulic cylinder, a clutch valve, which can be operated by an electronic control unit, and with which a hydraulic pressure applied to the clutch hydraulic cylinder can be adjusted, and a pressure sensor, with which the hydraulic pressure applied to the clutch hydraulic cylinder can be detected, are arranged, and having a charging hydraulic pump, which delivers hydraulic fluid into the hydraulic system in a charging process to increase the actual accumulator pressure.

A mechanical one way clutch, also known as a mechanical diode, is provided with a variable friction clutch that can be applied to smooth the engagement. An automobile or other wheeled vehicle includes various hydraulic components, including a hydraulic gearbox, transmission, clutch, and brake energy recovery system. Such hydraulic components supplement or replace traditional mechanical components of the automobile or other wheeled vehicle to improve the overall operational efficiency thereof.

A drop-in signal accumulator piston assembly replaces an original equipment (OE) signal accumulator piston in a vehicle transmission hydraulic circuit. The OE signal accumulator piston is positioned in a bore in a valve body that has an open end and a fluid port. The drop-in signal accumulator piston assembly includes a cylindrical sleeve having open first and second ends, one of the first and second ends defining a reduced diameter region, and a piston positioned in the sleeve. A spring is positioned in part in the piston and in part extending beyond and end of the piston. The sleeve is positioned in the valve body bore, with the piston, and the spring. A method for replacing an original equipment (OE) signal accumulator piston in a transmission hydraulic circuit is also disclosed.

A hydraulic fluid pressure amplifier system includes a boost cylinder assembly, an energy storage device in fluid communication with the boost cylinder assembly, and a working cylinder assembly. The boost cylinder assembly is configured to selectively receive a plunger member into a boost cylinder, wherein movement of the plunger member received in the boost cylinder compresses a charge fluid within a blind side volume of the boost cylinder from a first fluid pressure to an amplified fluid pressure greater than the first pressure. The working cylinder assembly is selectively operable responsive to receiving a source hydraulic fluid having a nominal fluid pressure less than the amplified fluid pressure for effecting the movement of the plunger member into the boost cylinder. The energy storage device is operable to selectively receive and store a portion of the charge fluid compressed to the amplified fluid pressure.

A work vehicle includes an engine, a speed changing apparatus that includes a hydrostatic stepless speed changing mechanism and is configured to subject motive power transmitted from the engine to speed changing and output the motive power, a travelling apparatus configured to travel on the motive power received from the speed changing apparatus, a speed detector configured to detect a speed of the travelling apparatus, a pressure detector configured to detect a hydraulic pressure in a closed circuit of the hydrostatic stepless speed changing mechanism, and a controller.

A hydraulic controlling system including: a cooling and lubricating oil line and a main controlling oil line; an oil-liquid storage; a first pump, wherein an inlet of the first pump is connected to the oil-liquid storage and an outlet of the first pump is connected to the main controlling oil line; a second pump, wherein an inlet of the second pump is connected to the oil-liquid storage and an outlet of the second pump selectively communicates with the cooling and lubricating oil line or the main controlling oil line; and a gearbox-gear-shifting oil line including a gear-shifting-pressure regulating valve, a plurality of gear-shifting-flow-rate controlling valves and a plurality of gear-shifting selector valves. The gear-shifting-flow-rate controlling valves are connected to the main controlling oil line via the gear-shifting-pressure regulating valve. At least some of the gear-shifting-flow-rate controlling valves are connected to a gear-shifting executing piston via the gear-shifting selector valves.

A hydraulic system for an automatic transmission of a motor vehicle, including a high pressure circuit in which a pressure accumulator, at least one clutch and a gear selector are connected, and comprising a low pressure circuit for cooling the clutch, wherein the high pressure circuit and the low pressure circuit have at least one hydraulic pump that can be driven by an electric motor, and including a control unit that actuates the electric motor of the hydraulic pump when a pressure accumulator charging requirement is detected, wherein the high and low pressure circuits are connected via a bypass line to an integrated accumulator charging valve.

A hydraulic control unit comprises a housing, an accumulator, a gear pump assembly, and a motor. The housing comprises an accumulator compartment, a gear pump compartment, and a flow path section connecting the gear pump compartment and the accumulator compartment, the flow path section comprising at least a supply path and a pressurizing path. The accumulator in the accumulator compartment comprises a movable piston dividing the accumulator compartment into a high pressure reservoir and a low pressure reservoir. A gear pump assembly is in the gear pump compartment. The gear pump assembly is configured to draw return fluid from the low pressure reservoir via the supply path and to pump pressurized fluid through the pressurizing path to accumulate in the high pressure reservoir. A motor assembly is connected to the gear pump compartment of the housing and is configured to power the gear pump assembly.

A hydro-mechanical hybrid transmission device with an energy management mechanism includes an input member, a mechanical transmission mechanism, an energy management mechanism, a power output mechanism, an output member, a convergence mechanism, a start mechanism, a hydraulic transmission mechanism, a clutch assembly, and a brake assembly. The clutch assembly connects the input member to the mechanical transmission mechanism, the power output mechanism, and the hydraulic transmission mechanism, and connects the energy management mechanism to the mechanical transmission mechanism and the power output mechanism. The clutch assembly and the brake assembly provide a continuous transmission ratio between the input member and the output member and/or the power output mechanism, between the energy management mechanism and the output member and/or the power output mechanism, and between the energy management mechanism together with the input member and the output member and/or the power output mechanism.

A transmission system includes a transmission assembly having clutches to transmit power from an input shaft to an output shaft at a plurality of gear ratios. A traction motor drives the input shaft and propels the work vehicle, while a controller controls operation of the transmission assembly and the traction motor. A hydraulic circuit controls actuation of the clutches responsive to commands from the controller. The hydraulic circuit includes a hydraulic pump driven by the traction motor, an accumulator connected to the hydraulic pump and that holds hydraulic fluid therein under pressure, and an unloading valve positioned in a secondary fluid path running from an outlet of the hydraulic pump to a sump. The unloading valve operates in a closed state to direct hydraulic fluid from the hydraulic pump to the accumulator and operates in an open state to direct hydraulic fluid from the hydraulic pump to the sump.