Abstract: A transmission unit comprises a planetary wheel set, which comprises a plurality of gearwheel elements and is designed as a pump which effects delivery of hydraulic fluid from a suction zone to a pressure zone of a pump casing containing the planetary wheel set by means of the gearwheel elements. A controllable throttling device is provided in order to selectively throttle a fluid flow pumped between the suction zone and the pressure zone and thereby to brake the gearwheel elements of the planetary wheel set relative to one another. A fluid reservoir, which can be connected simultaneously to the suction zone and to the pressure zone via the throttling device, is arranged in a pump casing interspace formed between a plurality of gearwheel elements of the planetary wheel set.

Abstract: A modification to the manual valve of an automatic transmission is provided which improves the shift quality of the automatic transmission when the transmission is shifted from a drive gear to either Park or Neutral. More particularly, the invention provides a control orifice which regulates the release of hydraulic fluid from one or more clutch circuits such that pressure to one or more clutches is gradually released. The gradual release of pressure form the one or more clutches provides an improved shift quality. In alternate embodiments, the present invention provides a further modification to an automatic transmission which allows the control orifice to be circumvented in situations where a rapid swap of pressure from on clutch control solenoid to another is required.

Abstract: A manual valve is provided between a mechanical oil pump and a clutch of an automatic transmission device for connecting an engine with the automatic transmission device, a first check valve is provided in a passage connecting the mechanical oil pump with the manual valve, and an electric oil pump is provided in parallel with the mechanical oil pump, wherein the electric oil pump is operated during an idling stop of the engine and an output side of the electric oil pump is connected to the passage between the first check valve and the manual valve so that the working fluid from the electric oil pump is supplied to the clutch of the automatic transmission device through the manual valve. Accordingly, the electric oil pump can be made smaller and the supply of the working fluid from the electric oil pump to the clutch can be prevented when it is not necessary.

Abstract: A torque transfer assembly for a motor vehicle comprises a ring gear subassembly and a differential subassembly rotatably supported in said ring gear subassembly, a friction clutch pack for coupling the ring gear subassembly to the differential subassembly, and a hydraulic clutch actuator for selectively frictionally loading the clutch pack. The hydraulic clutch actuator includes a variable pressure relief valve assembly to selectively control the friction clutch pack. The variable pressure relief valve assembly includes a valve closure member, a valve seat complementary to the valve closure member, and a electro-magnetic actuator for engaging the valve closure member and urging thereof against the valve seat with an axial force determined by a magnitude of an electric current supplied to the electro-magnetic actuator so as to selectively vary a release pressure of the pressure relief valve assembly based on the magnitude of the electric current.

Abstract: A drive axle assembly for use in an all-wheel drive vehicle having a first hydraulic coupling operable to automatically transfer drive torque to a secondary driveline in response to slip of the primary driveline and a second hydraulic coupling operable to bias torque and limit slip between the wheels of the secondary driveline.

Abstract: A pressure regulating valve regulates an original pressure outputted from a manual valve by means of a control pressure generated by a solenoid in a D range and supplies the regulated original pressure to an engaging element. An electronic control unit filters a current signal supplied to the solenoid to generate the control pressure by using a strong filter when a N range is switched to a D range during stoppage of a vehicle so that the control pressure has a gentle rise characteristic, switches the filtering process to a filtering process using a weak filter to rapidly move the pressure regulating valve in a working pressure discharge direction when the N range is switched to the D range during running of the vehicle and returns the filtering process to the filtering process using a strong filter after a predetermined time period. Thereby, occurrence of shock is suppressed when the D range is again selected after the N range is selected during running in the D range.

Abstract: A controlled type rotation speed difference sensitive coupling is disclosed, which is for use between first and second rotatable members. The coupling comprises a drive housing connected to the first rotatable member, a rotor connected to the second rotatable member and rotatably received in the housing, and driving pistons operatively carried by the rotor having head portions thereof slidably engaged with a cam surface wall formed on an inner surface of the drive housing. The rotor has at its center portion a spool chamber in which a spool is disposed. Balance passages and relief passages extend respectively between working chambers defined by the driving pistons and the spool chamber. Each balance passage has an orifice which is exposed to the spool chamber and closable by the spool. The orifice is non-circular in shape.