Abstract: A valve for controlling a clutch in a motor vehicle transmission. The valve includes a control spool that is movably received in a bore of a valve housing to control hydraulic flow to and from control channels in the housing and that open into the bore. The control spool is provided with a coating that includes at least one metal of the eighth sub-group and with a non-metal of the fifth main group of the periodic table.

Abstract: An active roll stabilization system of a vehicle having an axle with at least two wheels, wherein the axle is provided with a roll stabilizer that is actuated by means of a hydraulic device. The hydraulic device is actuated and controlled by at least one pressure control valve with a preselected pressure level by a pressure supply device, such as a pump. In order to reduce the costs for producing such an active roll stabilization system, the pressure control valve is pilot-operated by a pressure control pilot valve.

Abstract: A pressure limiting valve having a spool with raised spool lands. The spool is slidably received in a spool bore having inflow and outflow grooves that form control edges. The valve has two control edges, and a hydraulic resistance is connected in series with one of the control edges. Increasing static pressure losses at the control edges during flow, so-called flow forces, can be offset by an increasing back pressure on the valve spool, which is produced by the hydraulic resistance.

Abstract: The present invention broadly comprises a cone connection assembly for a torque converter, including: a first surface operatively arranged for connection to a crankshaft and a second surface on a cover of the torque converter. The first and second surfaces are arranged to be engaged and the first surface is arranged to transfer torque to the second surface via the engagement of the first and second surfaces. In some aspects, the crankshaft comprises a longitudinal axis, the first surface is disposed about the longitudinal axis, the cover comprises an outside surface, and the outside surface comprises the second surface. In some aspects, the first and second surfaces are arranged to be frictionally engaged or the first and second surfaces have complementary surface features and the first and second surface features are arranged to interlockingly engage.

Abstract: A multiple clutch assembly for use in the power train of a motor vehicle between a prime mover and a change-speed transmission. A hub is coupled to a pumping device for an operating fluid. The pumping device is located radially outwardly of two coaxial, interfitted input shafts of the transmission. Each of the transmission shafts is associated with a discrete one of two clutches. The placing of the pump radially outwardly of the input shafts of the transmission contributes to simplicity and lower cost of the multiple clutch assembly.

Abstract: An active roll stabilization system of a vehicle having an axle with at least two wheels, wherein the axle is provided with a roll stabilizer that is actuated by means of a hydraulic device. The hydraulic device is actuated and controlled by at least one pressure control valve with a preselected pressure level by a pressure supply device, such as a pump. In order to reduce the costs for producing such an active roll stabilization system, the pressure control valve is pilot-operated by a pressure control pilot valve.

Abstract: A method and apparatus for cooling a clutch of a motor vehicle by controlling a valve through which a coolant circuit is coupled with a pump circuit. The valve includes a control piston that is movable at least to actuate a connection between the coolant circuit and the pump circuit.

Abstract: A device for driving a plurality of hydraulic shift cylinders, especially shift cylinders for shifting gears of a twin-clutch transmission, includes a first slide valve having a control intake to which control pressure is applied, a system pressure intake to which system pressure is applied, two outlets and at least one return outlet, the one outlet being connected to the system pressure intake and the other outlet being connected to the return outlet, as desired, and a valve device connected to the outlets of the slide valve via which the shift cylinders may be selectively actuated.

Abstract: The invention relates to a hydraulic system comprising a multi-flow, especially dual-flow, hydraulic pressure supply unit, such as a pump, by which means a volume flow is supplied to a consumer. The invention is characterised in that a valve arrangement is provided for switching between the individual pump flows and/or for interconnecting the individual pump flows.

Abstract: A method for regulating or controlling the transmission ratio of an automatic power-branched transmission. Power is transmitted through a shaft driven by an engine, a variable speed drive, a gear transmission, a driven shaft, and at least two control clutches. The variable speed drive and the gear transmission are connected to each other in such a way that the regulating range of the variable speed drive is traversed in one direction within a first range of transmission ratios, and is traversed in the opposite direction within a second range of transmission ratios during traversing of the entire range of transmission ratios. The shifting strategies result in reduced wear of the endless belt device and allow for comfortable changing between the transmission ratio ranges.

Abstract: A multiple clutch assembly for use in the power train of a motor vehicle between a prime mover and a change-speed transmission. A hub is coupled to a pumping device for an operating fluid. The pumping device is located radially outwardly of two coaxial, interfitted input shafts of the transmission. Each of the transmission shafts is associated with a discrete one of two clutches. The placing of the pump radially outwardly of the input shafts of the transmission contributes to simplicity and lower cost of the multiple clutch assembly.

Abstract: A hydraulically operated automatic transmission assembly wherein a group of dynamic fluid consumers including a continuously variable transmission or a planetary change-speed transmission and a clutch is regulated by a unit which receives pressurized hydraulic fluid from a pump. The pump further serves to supply fluid to several static consumers, such as a torque converter and one or more cooling and/or lubricating units. The fluid which is supplied to the static consumers is influenced by a hydraulic resistor, such as a diaphragm or a throttle, and the quantity of such fluid is maintained within an acceptable range irrespective of eventual leakage of fluid which is being conveyed to the dynamic consumers and irrespective of pronounced fluctuations in the quantity of fluid being necessary for certain modes of operation of the dynamic consumers.

Abstract: A fluid pressure regulating valve, particularly for an automated clutch in the power train of a motor vehicle with a manually shiftable transmission, is adjustable by an electronic control unit which regulates the strength of alternating current being supplied to one or more electromagnets of the valve. The control unit receives signals from sensors which monitor the fluid pressure, the temperature and/or the RPM of one or more constituents of the motor vehicle, and such signals are processed into signals denoting differences between existing and desired pressures of fluid being supplied to and/or by the valve. These signals are compared with information stored in at least one memory of the control unit and denoting memorized differences between actual and desired current strengths. The memorized signals are altered when a comparison in the control unit indicates that the differences ascertained on the basis of signals transmitted by the sensors depart from differences denoted by the memorized information.

Abstract: A hydraulic system for a motor vehicle has at least one pressure restricting valve with a housing that has two or more connections. At least one conduit cross-section in the housing can be closed by means of a closing body that is movable axially against the action of an energy accumulator. At least a part of the axial travel of the closing body is damped by means of a damping device.

Abstract: A transmission for use in the power train of a motor vehicle has a rotary first component (such as a shaft), a second component which may but need not be rotatable, a fluid-conveying conduit having a first end portion extending into a first socket provided in the first component and a second end portion extending into a socket of the second component, a split-ring piston packing located in an external groove of the first end portion, and an O-ring received in an external groove of the second end portion. The O-ring prevents the conduit and the second component from rotating relative to each other.

Abstract: The invention relates to a pressure medium system with at least one valve and one pressure medium supply, whereby a differential pressure can be purposely controlled in a positive and negative pressure area, especially for controlling a torque converter lockup clutch of a hydrodynamic torque converter.

Abstract: A hydraulic system for a motor vehicle has at least one pressure restricting valve with a housing that has two or more connections. At least one conduit cross-section in the housing can be closed by means of a closing body that is movable axially against the action of an energy accumulator. At least a part of the axial travel of the closing body is damped by means of a damping device.

Abstract: A valve for regulating the rate of flow and/or the pressure of oil flowing to a transmission or another consumer in the power train of a motor vehicle has a piston which defines with the valve housing a chamber for one or more springs and for oil being admitted through a first inlet by way of a first conduit containing a first throttle. A second inlet admits pressurized oil from a pump, and such oil can be admitted into the consumer by way of a first outlet and a second conduit containing a second throttle and supplying oil to the first conduit. A second outlet can deliver oil from the second inlet to the sump in response to shifting of the piston. A hydraulic seal is established between the piston and the housing intermediate the chamber and the second outlet to prevent leakage of oil from the chamber into the second outlet. Oil leaking from the chamber could adversely influence the characteristics of oil flowing into the consumer.

Abstract: A transmission for use in the power train of a motor vehicle has a rotary first component (such as a shaft), a second component which may but need not be rotatable, a fluid-conveying conduit having a first end portion extending into a first socket provided in the first component and a second end portion extending into a socket of the second component, a split-ring piston packing located in an external groove of the first end portion, and an O-ring received in an external groove of the second end portion. The O-ring prevents the conduit and the second component from rotating relative to each other.

Abstract: A fluid-operated regulating apparatus for use in a motor vehicle, particularly to control the operation of a consumer, such as a clutch which transmits torque between an engine and a transmission in the power train of a vehicle as a function of one or more parameters, comprises at least one pump which supplies a flow of pressurized hydraulic or pneumatic fluid to the consumer by way of a valve controlled by an electronic unit which receives signals from a plurality of sensors. The signals which the electronic unit transmits to the valve are dependent upon at least one variable parameter which is generated by a plurality of components. One of these components is modulated or modulatable at a first frequency, and another of these components is modulated or modulatable at a second frequency which can be higher or lower than the first frequency.