A hydraulic control system includes a hydraulic pump driven by an electric motor, a solenoid valve having an output that controls the positions of a pressure regulator valve and a third, stator shift valve. The solenoid valve is a normally high, variable force solenoid valve which provides a control signal to the second and third valves. The second, pressure regulator valve is a multiple port valve which controls hydraulic fluid flow both to a transmission oil cooler (ATOC) and to an exhaust port, thereby maintaining a desired system pressure. The third, stator shift valve is also a multiple port valve and it controls fluid flow to the stator of the electric pump motor to provide cooling and to a dog clutch of the transmission to disengage it.

A hydraulic control system includes a hydraulic pump driven by an electric motor, a solenoid valve having an output that controls the positions of a pressure regulator valve and a third, stator shift valve. The solenoid valve is a normally high, variable force solenoid valve which provides a control signal to the second and third valves. The second, pressure regulator valve is a multiple port valve which controls hydraulic fluid flow both to a transmission oil cooler (ATOC) and to an exhaust port, thereby maintaining a desired system pressure. The third, stator shift valve is also a multiple port valve and it controls fluid flow to the stator of the electric pump motor to provide cooling and to a dog clutch of the transmission to disengage it.

A turbocompound unit for converting energy of an exhaust gas from an internal combustion engine to torque increase of a crankshaft of the internal combustion engine includes a turbine arrangement and an arrangement configured to operatively connecting the turbine arrangement to the crankshaft is a hydrodynamic coupling and freewheeling arrangement. The turbocompound unit further includes a brake arrangement, wherein the brake arrangement and the freewheeling arrangement are located on an opposite side of the hydrodynamic coupling in relation to the turbine arrangement.

At the time when a hydraulic actuator is operated to engage a dog clutch, after it is detected that a hydraulic pressure for operating the hydraulic actuator is higher than or equal to a predetermined hydraulic pressure, it is determined whether the dog clutch is not engaged. Therefore, non-engagement determination due to insufficient hydraulic pressure for operating the hydraulic actuator is prevented. Thus, at the time when the hydraulic actuator is operated to engage the dog clutch, it is possible to prevent consumption of time to engage the dog clutch due to unnecessary re-engagement operation.

The clutch piston assembly includes a one piece piston body which extends about an axis and has at least one radially inwardly facing surface and at least one radially outwardly facing surface. At least one seal is engaged with the piston body and extends either radially outwardly from the radially outwardly facing surface or radially inwardly from the radially inwardly facing surface. The seal is made of polyetheretherketone (PEEK) or polyaryletherketone (PAEK) for establishing a low friction and fluid tight seal between the piston body and a wall in the automatic transmission.

A master cylinder for a hydraulic brake system or clutch system, in particular of a vehicle steered by handlebars, in particular of a bicycle, includes a housing containing a piston chamber. The housing accommodates a piston slidable therein and a pressure chamber. A compensating chamber communicates with the pressure chamber through at least one compensating bore. The housing has an attachment portion for attachment to a handlebar tube and the compensating chamber extends to the attachment portion and has a separating member for separating the hydraulic fluid from a compensating volume. The attachment portion has a clamping part made and arranged to attach the separating member to the attachment portion.

A clutch release bearing (17), in particular for a motor vehicle, having: a tubular body (30) through which at least one input shaft (11) of a gearbox is intended to pass; at least one actuator having a part, movable in translation along the axis (X) of the body (30), intended for actuation of a clutch diaphragm; a target (28a, 28b) whose position is representative of the position of the movable part of the actuator; and a detector (29a, 29b) capable of detecting the position of the target (28a, 28b). The target (28a, 28b) is offset angularly from the detector (29a, 29b) with respect to the axis (X) of the body (30).

A clutch release bearing (17), in particular for a motor vehicle, having: a tubular body (30) through which at least one input shaft (11) of a gearbox is intended to pass; at least one actuator having a part, movable in translation along the axis (X) of the body (30), intended for actuation of a clutch diaphragm; a target (28a, 28b) whose position is representative of the position of the movable part of the actuator; and a detector (29a, 29b) capable of detecting the position of the target (28a, 28b). The target (28a, 28b) is offset angularly from the detector (29a, 29b) with respect to the axis (X) of the body (30).

A hollow double-acting cylinder assembly may be mounted over a shaft and to a housing. A moveable piston of the cylinder assembly connects to a sliding sleeve of an over-center mechanism and the sliding sleeve with a thrust bearing allowing it to push and pull the sleeve mechanism with cylinder action. A toggle action of the over-center mechanism locks clutch without the need to sustain pressure on the cylinder after engagement/disengagement motion. As the clutch is typically engaged for sustained periods of time, this prevents constant hydraulic pressure applied to the over-center mechanism and significantly reduces wear. Hydraulic/pneumatic hoses may pass through the housing and connect to engage and disengage bores of the cylinder via remotely actuated control valve(s).

The present invention relates to a hydrostatic clutch actuator (1) for a clutch, in particular a wet clutch, of a motor vehicle, wherein the clutch actuator (1) has a drive unit (2, 3), a master cylinder-piston-cylinder unit (4, 5) driven thereby, a hydraulic reservoir (6) fluidically connected to the master cylinder-piston-cylinder unit, and a hydraulic system for actuating the clutch, wherein, by use of the master cylinder-piston-cylinder unit (4, 5), hydraulic medium can be conveyed out of the hydraulic reservoir (6) into the hydraulic system and the hydraulic system can be pressurized, and the hydraulic reservoir (6) has an overflow (10), via which hydraulic medium can be discharged from the hydraulic reservoir (6) and the hydraulic system.