Zf Batavia L.l.c.

Zf Friedrichshafen Ag

Friedrich Reiter

Wolfgang Danz

Ralf Vorndran

Andreas Piepenbrink

Andreas Schwenger

Friedemann Jauch

Markus Eisele

Ulf Lang

Bernd Fessler

Peter Wendel

Manfred Escher

Ralf Baus

Wolf Dieter Gruhle

A method for operating a drive-train of a motor vehicle. The drive-train having a transmission connected between a drive aggregate and a drive output. A hydrodynamic starting element is connected between the drive aggregate and transmission. The starting element includes a converter and converter lock-up clutch. A Power Take-Off (PTO) can be coupled to the drive aggregate on the drive aggregate side to take up drive torque delivered by the drive aggregate. In order to determine the torque taken up by the PTO, the lock-up clutch is operated in a rotational-speed-regulated manner at least when the PTO is coupled to the drive aggregate in order to set a defined target slip at the lock-up clutch. As a function of the actuation pressure of the lock-up clutch required for setting the target slip when the PTO is coupled, the torque taken up by the PTO is determined.

Method and control unit for operating a drivetrain of a motor vehicle comprising a power take-off

The invention concerns an oil supply system for an automatic transmission of a motor vehicle having one hydrodynamic starting element. It has one oil pump ( ) to convey oil to a variator ( ) and/or to shifting elements ( ), to a converter unit ( ) that can be supplied with oil via two oil lines ( ), especially a hydrodynamic torque converter ( ) having a converter lock-up clutch ( ), and to a lubrication device ( ), the same as at least one filter device ( ) and one oil cooling device ( ). Here are provided one prioritized primary circuit ( ) with a main pressure adjusted by a main pressure valve ( ) for pressure supply of the variator ( ) and/or of the shifting elements ( ) and a secondary circuit ( ) for oil supply of the lubrication device ( ). It is proposed according to the invention that the converter unit ( ) be tied to the primary circuit ( ) and to the secondary circuit ( ) so that the converter lock-up clutch ( ) be supplied with a minimum pressure required for torque transmission via the primary circuit ( ) parallel to the supply of the lubrication device ( ) via the secondary circuit ( ) when on the converter lock-up clutch ( ) a closing or slipping state is adjusted and that otherwise the converter unit ( ) is supplied with oil via the secondary circuit ( ).

Oil supplying system for an automatic transmission with a hydrodynamic starting device

In a method for controlling the multiplication for a continuously variable transmission with electrohydraulic control by means of a control loop having a linear PID controller with the specified multiplication of the variator iv_soll as command variable, the actual multiplication iv as regulating variable and the multiplication changing speed as correcting variable, the correcting variable delivered by the PID controller is limited to limiting values determined by the design for an upshift and downshift wherein said limiting values are calculated form the limits determined by construction and from the operating-point dependent limits determined by volume flow and the intersection of both admissible intervals determined by construction and by volume flow is defined as admissible multiplication changing speed range.

Method for determining adjusting speeds in a continuously variable transmission

Within the scope of the method for including the temperature in the calculation of the definite, operating-point dependent maximum and minimum adjustment speeds in a continuously variable belt-drive transmission, the actual limiting values for the maximum possible adjustment gradient are continuously calculated in every operating state by a physical-mathematical pattern wherein the hydraulic routes of the variator, the clutches integrated in the transmission and the lubrication are modeled as laminar inserts and the route of the control unit leakage as coupled laminar and turbulent hydraulic transmission elements.

Method of calculating for the speed control of a CVT

Process for controlling an automatic gearbox

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Kressbronn, Germany

Friedrich Reiter