Zf Friedrichshafen Ag

Zf Batavia L.l.c.

Other

Zf Transmission Technologies, L.l.c.

Stefan Sommer

Bernd Fessler

Andreas Piepenbrink

Hubert K&ouml;nig

Klaus Gessler

Todd R Brown

Peter Epe

Holger Bacher

Christian Fritzsche

Bernhard Fessler

Hebert Mozer

Steffen Braun

A hydraulic system of a CVT transmission of a motor vehicle is proposed, which has an oil pump for conveying oil from an oil sump to a variator comprising a first pulley set and a second pulley set. In each case, a valve mechanism is provided for controlling a pressure acting on the pulley set concerned. Between the valve mechanisms associated with the respective pulley sets is arranged a pressure selector valve, whose position determines which of the the valve mechanisms controls a main pressure to be delivered by the oil pump.

Hydraulic system for a CVT-transmission of a vehicle

A system for maintaining hydraulic pressure in a vehicle hydraulic system when the vehicle is stopped or idling. A hydraulic pressure reserve system includes a primary hydraulic circuit that includes a hydraulic pump and a hydraulic sump and that provides hydraulic pressure to at least a hydraulically actuated transmission and an accumulator tank and control valve connected from the primary hydraulic circuit for storing a reserve of hydraulic fluid at an accumulator pressure. An accumulator control valve, such as a bi-directional valve, allows a flow of hydraulic fluid between the primary circuit and the accumulator tank according to the primary circuit pressure to raise the primary circuit pressure towards a desired pressure. The hydraulic pressure reserve system may include a primary gear connected from a primary drive and driving an auxiliary secondary gear with a primary drive clutch for connecting the secondary gear to drive the hydraulic pump and an auxiliary drive clutch for connecting the auxiliary secondary gear or a drive chain to drive the hydraulic pump.

Method and apparatus for maintaining hydraulic pressure when a vehicle is stopped

A method of adjusting an operating temperature of a control device ( ) of a motor vehicle automatic transmission. The transmission control has a hydraulic unit ( ) and an electronic unit ( ) with electronic modules. The control device ( )is situated in a transmission housing which is partially filled with transmission oil and at least partly surrounded by transmission oil. The control device ( ) has a cooling device ( ) by which at least part of the electronic unit ( ) is cooled with the transmission oil. The transmission oil has a temperature &THgr; which is lower than a prevailing transmission oil temperature &THgr; . The electronic unit ( ) is impinged upon with a defined volume flow of the transmission oil.

Cooling a control device of the gearbox of a motor vehicle

The invention describes a method and a device for controlling a drive train of a motor vehicle with a drive assembly and a continuously variable automatic transmission with a variable speed gear, wherein an electronic control unit for controlling at least the continuously variable automatic transmission and an emergency device are provided, with this unit being activated in the event of failure of the electronic control unit and a constant pressure/force ratio being established in the variable speed gear. Pursuant to the invention, in the event of failure of the electronic control unit the frictional connection between the drive assembly and the continuously variable automatic transmission is interrupted before the emergency driving mode is made available through the emergency device by re-establishing the frictional connection.

Method and device for controlling a drive-line including a CVT

A plug-in connector for establishing an electrical connection between two regions separated by a wall having a mounting hole includes a connector part having electrical contacts and located on one side of the wall. A guide bushing is located on the other side of the wall. The lower end of the guide bushing passes through the mounting hole to bear the plug contacts. The connector part and the guide bushing connect when the guide bushing is rotated with respect to the connector part such that connector part and the guide bushing are aligned longitudinally. The connector part is held on the wall such that the connector part is aligned with the mounting hole and is movable along the longitudinal axis of the guide bushing. A stop limits the movement of the connector part away from the guide bushing which is affixed on the wall opposite the connector part.

Electric plug connector having holder for holding first connector part on first wall side and enabling rotation of guide sleeve on second wall side with respect to first connector part

In an assembly of an electronic element ( ) and a hydraulic element ( ) of a control device ( ) for the automatic transmission of a motor vehicle with a partially oil filled transmission housing wherein the control device ( ) is arranged in the transmission housing wherein said control device ( ) is arranged in the transmission housing and is at least partially surrounded by oil, the hydraulic element ( ) has a valve housing ( ) on which hydraulic valves ( ), speed sensors ( ) and pressure sensors ( ) are provided and is designed with a first housing part ( A) and a second housing part ( B). The first housing part ( A) has an at least approximately cuboid shape and is substantially arranged below a set of conical disks ( A) of a variator ( ).

Assembly for an electronic element and a hydraulic element of a control device for the automatic transmission of a motor vehicle

The invention is based on an electronic-hydraulic control unit ( ) for an automatic transmission of a motor vehicle wherein the control unit ( ) has one hydraulic unit ( ) with hydraulic valves ( ), sensors ( ) and pressure regulators ( ) and one electronic unit ( ) with a microprocessor, memories, sensors and power regulators ( ) which form a functional unit. To reduce the tolerances of the control unit, it is proposed that the pressure tolerances appearing in the operating range be detected by verifying characteristic lines and from the divergences relative to a set characteristic line, plotting and storing in a memory a corresponding characteristic line correction.

Electronic-hydraulic control unit for an automatic transmission for vehicles

A system for control of a CVT driven by a drive unit has an electromagnetically controlled pressure-control valve which actuates both a main pressure valve and a secondary valve for the secondary pulley wherein geometry and spring tension of a main pressure valve and the secondary valve provide different characteristic lines.

Hydraulic control system for a CVT

The electrical plug-in connection for connecting one electronic module within an automatic transmission for motor vehicles with a feed line provided outside the housing have a plug which penetrates a bore with play in the housing. A matching plug in the shape of a bushing wherein plug and matching plug are provided with grooves or ribs to form a bayonet interlocking. In the space between the plug and the bore is provided a molded seal which, when the matching plug is slipped on, becomes deformed and hermetically seals the bore.

Growing community of inventors

Saulgau, Germany

Stefan Sommer