A first valve is disposed in an oil passage through which the engaging pressure generated by a linear solenoid valve is supplied to A second brake. The first valve is closed when the second brake is released, so as to close the oil passage, and is opened when the second brake is engaged, so as to open the oil passage. A second valve is disposed in a lubricating oil passage through which lubricating oil is supplied to the second brake, and communicates with the linear solenoid valve. The second valve is opened when the engaging pressure is supplied from the linear solenoid valve, so as to open the lubricating oil passage, and is closed when no engaging pressure is generated by the linear solenoid valve.

A transmission where a first shaft is rotationally fixable to a third shaft and to a second shaft, the second and third shafts are rotationally connectable to a fourth shaft, the second shaft is rotationally connectable to a fifth shaft, the fourth shaft is rotationally connectable to the fifth shaft, the third shaft is rotationally connectable to the fifth shaft, fixed gears of the fourth and fifth shafts are rotationally connected to a drive output, a first gearwheel of the sixth shaft meshes with a fixed gear of the second shaft, and a second gearwheel of the sixth shaft meshes with a fixed gear of the third shaft. Moreover, a first gearwheel of the sixth shaft is an idler gear and a second gearwheel of the sixth shaft is a fixed gear, or vice versa. Additionally, the idler gear of the sixth shaft is rotationally fixable to the sixth shaft.

A transmission having planetary gearsets (RS1, RS2, RS3, RS4, RS5). Elements (ST2, ST4) of gearsets (RS2, RS4) form input and output shafts, respectively. Element (SO1) of gearset (RS1) couples element (HO5) of gearset (RS5) and can be immobilized by shift element (A). Element (ST1) of gearset (RS1) couples element (HO4) of gearset (RS4). Element (HO1) of gearset (RS1) can be immobilized by shift element (B). Elements (SO4, ST2) of gearsets (RS4 RS2) can connect by shift element (C). Elements (HO2, SO3, SO5) of gearsets (RS2, RS3, RS5) couple and can couple element (SO4) of gearset (RS4) by shift element (E). An element of gearset (RS4) is connected to an element of gearset (RS3), while another element of gearset (RS4) can be connected by shift element (D) to another element of gearset (RS3). Elements (SO2 ST5) of gearsets (RS2, RS5) are connected and can be immobilized by shift element (F).

A system for a driveline is provided. In one example a driveline may include a first and a second input shaft gear disposed on an input shaft. In one example, the first input shaft gear may selectively drivingly engage with the input shaft via a first clutch and the second input shaft gear may selectively drivingly engage with the input shaft via a second clutch. In another example, a first and a second counter shaft gear may be disposed on a countershaft and drivingly engage with the countershaft, wherein the first input shaft gear drivingly engages with the first countershaft gear and the second input shaft gear is drivingly engages with the second countershaft gear via an idler gear.

A dual-clutch transmission for use in a vehicle has a housing, a clutch pack drum adapted to rotate inside the housing, a central clutch gear connected to the clutch pack drum, a first clutch pack, a first clutch hub, a first pressure plate disposed on the first side of the central clutch gear, and a first shaft connected to the first clutch hub. The first shaft drives at least one first transmission gear when the first pressure plate squeezes the first clutch pack. The dual-clutch transmission further includes a second clutch pack, a second clutch hub, a second pressure plate disposed on the second side of the central clutch gear, and a second shaft connected to the second clutch hub. The second shaft drives at least one second transmission gear when the second pressure plate squeezes the second clutch pack. A vehicle having a dual-clutch transmission is also encompassed.

Methods and systems for transmission control are provided. In one example, a transmission system operating method includes maintaining a displacement set-point of a variable displacement hydraulic motor in a hydrostatic assembly within a working zone, where at least a portion of a boundary of the working zone is determined based on a torque constraint of the hydrostatic assembly. The transmission system includes the hydrostatic assembly that includes the hydraulic motor that is hydraulically coupled in parallel with a variable displacement hydraulic pump and a gearbox mechanically coupled to the hydrostatic assembly and including one or more clutches.

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 powertrain for an electric vehicle, may include: an input shaft and an output shaft mounted in parallel to each other; first and second power transmission mechanisms provided to transmit power from the input shaft to the output shaft at two gear ratios different from each other; a one-way clutch included in the first power transmission mechanism; a friction clutch included in the second power transmission mechanism; and a bypass mechanism provided to form a power transmission path that bypasses the one-way clutch and a power transmission path that bypasses the friction clutch.

A drive assembly for a work vehicle includes a drive housing, a drive shaft rotatable about a drive axis, an inner hub rotationally fixed to the drive shaft, and a planetary gear set coupled to the drive shaft and configured to selectively rotate an output element. The drive assembly also includes a clutch arrangement having a clutch ring configured to selectively engage the planetary gear set. The clutch arrangement further includes a guide assembly mounted on the clutch ring and configured to selectively interact with the planetary gear set to effect disengagement of the clutch ring from the planetary gear set. A clutch actuation assembly is configured to effect movement of the clutch arrangement along the drive axis to engage the planetary gear set, and a guide actuation assembly is configured to operate the guide assembly to interact with the planetary gear set.

A seal structure between an oil outlet formed in a first case and an oil inlet formed in a second case and having an end face facing an end face of the oil outlet with a clearance between the end faces, the seal structure including an annular first seal disposed in an increased-diameter hole, which is formed on an outlet side or an inlet side of an oil passage in one of the oil outlet and the oil inlet and has a larger diameter than the oil passage, such that the first seal contacts a step surface located at a boundary between the oil passage and the increased-diameter hole; and an annular second seal harder than the first seal and disposed in the increased-diameter hole such that the second seal contacts the first seal and the end face of the other of the oil outlet and the oil inlet.