Abstract: A hydraulic clutch includes friction plates to transmit motive power, a piston movable between (i) a pressing position, at which the piston presses the friction plates for the hydraulic clutch to be engaged to transmit motive power, and (ii) a separated position, at which the piston is spaced apart from the friction plates for the hydraulic clutch to be disengaged to block motive power, the piston being movable into the pressing position in response to receiving hydraulic fluid to move the piston toward the pressing position, and a holder to (i) hold the piston at an intermediate position between the pressing position and the separated position in response to the piston coming into contact with the holder and (ii) release the piston from the intermediate position.

Abstract: A clutch device for a motor vehicle includes a disc pack and an actuation device. The disc pack includes an outer disc pack and an inner disc pack arranged. The actuation device includes a retaining element, a primary piston, a secondary piston and a spring element. The primary piston and the secondary piston are each arranged on the retaining element in an axially displaceable manner and delimit respective pressure chambers. The spring element is integrally formed with the secondary piston and connects the primary and secondary pistons. When a pressure is applied to a pressure medium in the primary pressure chamber, the primary piston is arranged to move the outer disc pack against the inner disc pack and frictionally transmit torque. When a pressure is applied to a pressure medium in the secondary pressure chamber, the secondary piston is arranged to move the primary piston against the outer disc pack.

Abstract: A wet clutch system includes fluid-flow apertures in the clutch piston which allow for reduction of oil shear forces between rotating clutch plates and a stationary piston. In particular the apertures pass through the piston in the area of the piston's engagement with the clutch plates. When the piston is in its deactivated position and spaced from the clutch plates, the radially-outward position of these apertures allows high-pressure, centrifugally-driven clutch fluid to migrate away from the clutch plates through the piston to a backfill cavity on the opposite side of the piston. An air-inlet aperture may be provided in or near the clutch hub to facilitate this oil migration.

Abstract: A piston (50), comprising: •a shaft side (52) with a first circumferential groove, said first circumferential groove (90) bounded by a continuous circumferential seal plateau (88), said seal plateau extending axially outward from said first circumferential groove, wherein a planar outboard surface (96) extends radially outboard from said seal plateau; •a clutch side (54) having two grooves alternating with two lands (102, 108); •an inner circumferential surface (56) having a seal groove (62) formed therein; and an outer circumferential surface (58) with a having a seal groove (76) formed therein, wherein the sides and surfaces form a ring shape.

Abstract: A powertrain module includes an input, a bulkhead supporting the input, a rotor support, a torque converter casing driveably connected to the rotor support, an electric machine including a stator supported on the bulkhead and a rotor connected to the rotor support, a clutch hub driveably connected to the input, and a clutch for alternately opening and closing a drive connection between the clutch hub and the rotor support.

Abstract: A hydraulic valve assembly for controlling a clutch in a vehicle transmission. The valve assembly includes a housing with a first port for connection to a source of pressurized hydraulic fluid, a displaceable sealing piston disposed within the housing, a valve spring for displacing the sealing piston, a snap-spring having first and second equilibrium positions, and an overstroke spring. In the first equilibrium position a spring force displaces the sealing piston to uncover the first port to enable fluid flow through the valve, and in the second equilibrium position the valve spring displaces the sealing piston to block the first port to block fluid flow through the valve. Moving from the first equilibrium position to the second equilibrium position includes displacing the overstroke spring.

Abstract: A torque converter assembly includes a cover for driving engagement with a prime mover, a piston plate including an annular surface for engaging a clutch, and a first seal disposed radially inward of the annular surface. In a lockup mode for the torque converter, the first seal blocks fluid flow through an orifice in the piston plate or between the cover and the piston plate and, in a release mode for the torque converter, the first seal is deflectable to enable a fluid flow through the orifice or between the cover and the piston plate and around the first seal. In an example embodiment, the torque converter assembly includes an apply chamber, the piston plate is displaceable in response to fluid pressure in the apply chamber, and the first seal is arranged to be deflected by the fluid pressure in the apply chamber.

Abstract: A clutch device for a vehicle includes an input shaft, an output shaft coaxially arranged with a rotational axis of the input shaft, first clutch plates, second clutch plates, a piston fitted to a cylindrical portion integrally formed with the output shaft or the input shaft, an elastic member arranged between the piston and the cylindrical portion, a hydraulic chamber defined by the cylindrical portion and the piston, a canceller chamber defined by the cylindrical portion and the piston to connect to an outer side of the cylindrical portion via a discharge hole formed at a portion of the cylindrical portion, the portion being located at a predetermined radial distance from the rotational axis, and a throttle hole formed in a portion of the piston to connect the hydraulic chamber to the canceller chamber, the portion being located at a radially inward side of the portion of the cylindrical portion.

Abstract: A clutch arrangement includes a housing filled with fluid, a first friction surface formation rotatable with the housing around an axis of rotation, a second friction surface formation rotatable with a driven element around the axis of rotation, a pressing element rotatable with the housing around the axis of rotation and which divides an interior space of the housing into a first spatial area and a second spatial area. Depending on fluid pressure in the first and fluid pressure in the second spatial areas, the pressing element is movable with respect to the housing for producing and canceling a frictional engagement between the and the second friction surface formations. A fluid supply system for the first spatial area and/or the second spatial area includes at least a first fluid flow path. The fluid can be supplied to the associated spatial area via at least one fluid flow path and fluid can be removed from the associated spatial area via at least one fluid flow path.

Abstract: A clutch can comprise driving clutch plates spline-fitted on an input member, driven clutch plates arranged alternately with the driving clutch plates and spline-fitted on an output member, a clutch piston having one surface facing an oil pressure chamber and another surface facing the clutch plates and adapted to be displaced toward the plates by supplying oil to the oil pressure chamber and to be returned by discharging the oil from the chamber. A valve can pass through the clutch piston and be adapted to be closed for preventing oil from exiting the chamber to the other side of the clutch piston when the clutch is clutched-on and to be opened and allow airflow to the oil pressure chamber when the clutch is clutched-off. One or more weight reduction recesses can be formed on one surface of the clutch piston near the outer circumference further radially outward than the valve.

Abstract: A wet type multiple disc clutch transmits torque from an engine a transmission and a clutch engaging portion, a piston, a first oil passage, a second oil passage, and an operating oil supply unit. The clutch engaging portion includes a plurality of plate members. The first oil passage has one end on the piston side. The second oil passage has one end on the clutch engaging portion side. The operating oil supply unit switches a clutch engaged state, in which operating oil is supplied to the first oil passage from the outside and the operating oil in the second oil passage is drained to the outside, to a clutch disengaged state.

Abstract: A clutch assembly for an agricultural work vehicle having a piston slidably disposed within a chamber having a first portion and a second portion. The piston is positionable between a first position and a second position in response to a fluid pressure within the first portion of the chamber to actuate a clutch mechanism. A sealing ring is associated with the piston to substantially prevent flow of fluid between the first portion and the second portion when the piston is in the first position. A bleed assembly is configured to permit flow of fluid between the first portion and the second portion when the piston is in the first position. The bleed assembly allows sufficient flow to substantially prevent unintentional engagement of the clutch mechanism.

Abstract: A transmission having a shaft driven by a prime mover such as an engine or motor is provided. The transmission includes a first stationary element for supporting the shaft for rotation, and a torque transmitting device connectable to the shaft and rotatable about an axis. The torque transmitting device is actuated by a hydraulic fluid. A first passage is connected to the torque transmitting device and is in communication with the hydraulic fluid. The first passage extends radially inward from the torque transmitting device. A vent passage is located within the first stationary element and is in communication with the first passage. Rotation of the torque transmitting device about the axis separates entrained air from the fluid and urges air radially inward through the first passage and into the vent passage, thereby removing air from the hydraulic fluid and circuit.