A vehicle drive device includes a drive shaft to be driven by a drive source, a rotation transmission unit that transmits rotation input from the drive shaft to a wheel, a mechanical oil pump that generates a hydraulic pressure by the rotation of the drive shaft, an electric oil pump that electrically generates a hydraulic pressure, a hydraulic control device that supplies lubricating oil to the rotation transmission unit based on the hydraulic pressures generated by the mechanical oil pump and the electric oil pump, a drive circuit that controls electric power to be supplied to the electric oil pump, and a control unit that controls a drive condition of the drive circuit. The control unit stops the drive circuit and shuts down the electric oil pump when a temperature of refrigerant for cooling the drive circuit is equal to or higher than a third start temperature.

Proposed is a system for operating and lubricating a clutch of a work vehicle. The system includes a forward-backward switching clutch portion connected to a first transmission hydraulic line, a main transmission clutch portion connected to the first transmission hydraulic line so as to be disposed in parallel with the forward-backward switching clutch portion, an auxiliary transmission clutch portion connected to a second transmission hydraulic line disposed in parallel with the first transmission hydraulic line, and a lubricating oil supply portion configured to supply oil as a lubricant to each clutch friction element. The lubricating oil supply portion includes a clutch lubrication valve unit, and is configured to always allow oil supply to the clutch friction elements of each of the main transmission clutch portion and the auxiliary transmission clutch portion, and is configured to intermittently allow oil supply to the clutch friction element of the forward-backward switching clutch portion.

A compact transaxle is provided with a multi-speed transmission mechanism having transmission shafts extended in a longitudinal direction so that the transaxle can be combined with an engine having a crankshaft in the longitudinal direction. A bevel gear serving as an output member of the multi-speed transmission mechanism having the transmission shafts meshes with a bevel gear provided on a speed-reduction intermediate shaft extended parallel to a pair of differential yoke shafts of a differential mechanism extended in a lateral direction. A single transaxle casing incorporates the multi-speed transmission mechanism, the differential mechanism, and a speed-reduction mechanism including the speed-reduction intermediate shaft, thereby constituting the transaxle.

A transfer gearbox device, comprising a differential gear with a crown wheel in a first oil chamber, and a friction clutch in a second oil chamber. The first oil chamber comprises a first oil sump and the second oil chamber comprises a second oil sump. A valve is between the first oil chamber and the second oil chamber. When the valve is open, oil can pass via the valve out of the first oil chamber into the second oil chamber. When the valve is closed, oil cannot pass via the valve out of the first oil chamber. When the valve is open, by rotating the crown wheel, oil is conveyed by the crown wheel from the first oil sump into a first oil collector and is guided therefrom via a first oil guide and via the valve to the friction clutch cool and/or to lubricate the friction clutch.

An automatic transmission includes: a frictional engagement element including first and second annular friction plates; a pressing member moving in the axial direction relative to the transmission case and press the frictional engagement element in the axial direction; and a lubricating oil. Further, the transmission case includes a contact portion on the inner wall so that the contact portion is separated from a back surface of the pressing member when the frictional engagement element is in an engagement state and comes into contact with the back surface of the pressing member when the frictional engagement element is in a disengagement state.

A hydraulically actuated transmission includes a selecting switching valve configured to selectively switch between a first switching valve and a second switching valve as a valve to be connected with an outlet port of a solenoid valve. The selecting switching valve is configured to operate in response to a hydraulic pressure applied to a specific frictional coupling element (second brake) in accordance with coupling and releasing of the specific frictional coupling element, and is configured to connect the outlet port with the first switching valve while the hydraulically actuated transmission is in high gear which is higher than or equal to a predetermined gear, and connect the outlet port with the second switching valve while the hydraulically actuated transmission is in the low gear which is lower than the predetermined gear.

The present invention discloses a dual-clutch automatic transmission cooling and lubrication hydraulic control system and a vehicle. The dual-clutch automatic transmission cooling and lubrication hydraulic control system comprises a clutch lubrication control valve whose outlet end is connected with a clutch lubricating oil circuit, a gear lubrication control valve whose outlet end is connected with a gear and bearing lubricating oil circuit, the inlet end of the gear lubrication control valve being connected with the inlet end of the clutch lubrication control valve in parallel at the first common end, further comprises a mechanical pump and an electronic pump whose inlet ends are connected to an oil tank respectively. The outlet end of the mechanical pump and the outlet end of the electronic pump are connected in the second common end in parallel, and a cooler disposed between the first common end and the second common end. The dual-clutch automatic transmission cooling and lubrication hydraulic control system disclosed herein have a variety of working modes, reducing the defects such as large displacement of the mechanical pump when working alone.

A vehicular power transmitting system including a power transmitting member, an oil pump, and an oil piping assembly, and the oil piping assembly includes an oil piping body having an oil inlet and fixed, and a branch pipe. The branch pipe has a width direction parallel to a longitudinal direction of the oil piping body, and includes proximal and distal end portions. The proximal end portion is connected to the oil piping body, and the distal end portion has a delivery nozzle from which the oil is delivered toward the lubricated portion. The branch pipe has an opening formed in the proximal end portion, for communication of the branch pipe with the oil piping body, the opening having a dimension in a width direction of the branch pipe, which dimension is larger than a dimension of the distal end portion in the width direction of the branch pipe.

A hydraulic control device (1) for an automatic transmission includes: a variable displacement oil pump (10); a regulator valve (30); and a lubrication control valve (50) configured to select whether or not oil discharged from the variable displacement oil pump (10) is to be supplied to a to-be-lubricated portion. The lubrication control valve (50) has a control port (54) connected to an open/close port (38) of the regulator valve (30). A controlled pressure at the control port (54) is changed in response to opening and closing of the open/close port (38) to select whether or not the oil is to be supplied to the to-be-lubricated portion.

An engine clutch device includes first and second alternately stacked frictional power transmitting members and a clutch pressure member for axially bringing the frictional power transmitting members into pressure contact. The clutch device includes an oil supply portion adjacent to a distal end of power transmission shaft. The clutch device has an oil supply structure including a clutch lifter member with a flange portion axially facing the distal end of power transmission shaft, to axially shift the clutch pressure member to release the pressure contact of the frictional power transmitting members. The flange portion has a bowl-shaped portion extending axially to surround the one end portion of the power transmission shaft. The bowl-shaped portion including the flange portion functions to guide oil axially inward along the power transmission shaft and serves to provide an improved oil supply effect to the frictional power transmitting members.