Volkswagen Ag

Carsten Adomeit

Rainer Hofmann

Georg Kruse

Ansgar Damm

Shaun E Mepham

Lloyd Storey

Robert Robinson

John Lipman

Wolf-Rüdiger Lutz

Peter Merk

Axel Zergiebel

Stuart Holden

Dirk Nicke

Richard G Griffiths

A hydraulic circuit for a motor vehicle transmission, preferably a twin-clutch transmission, is connected for cooling at least one clutch of the transmission. The hydraulic circuit is preferably a low-pressure circuit and it includes at least one hydraulic pump, at least one filter element, for filtering the hydraulic oil, and at least one pressure-regulating valve. The circuit-related control sequence and the power consumption of the hydraulic pump are optimized in that at least one adjusting valve is provided in order to control the volume flow of cooling oil flowing to the clutch, in that a pressure-compensation valve is provided in addition, and in that the pressure-regulating valve, the adjusting valve and/or the pressure-compensation valve are arranged and/or formed within the hydraulic circuit such that the pressure difference between the supply pressure and the establishing cooling-oil pressure is essentially constant.

Hydraulic circuit for a transmission of a motor vehicle

A transmission, in particular an automated shift transmission, includes a plurality of selectable and deselectable gear stages for implementing gear changes. The selection and deselection of the gear stages is achieved with the aid of coupling units, in particular with the aid of engageable and disengageable sliding collars. The coupling units are activatable via respective shift rails and respective actuators. The shifting times are reduced and a compact construction of the transmission is achieved by virtue of the fact that a plurality of gear stages is assigned to at least two different shift rails in such a way that respective successive gear stages are assigned to respective different shift rails. As a result, the respective shift rails can be activated at least partially simultaneously in the case of a sequential gear change. A method for controlling a transmission is also provided.

Transmission and method for controlling a transmission for a motor vehicle

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Hannover, Germany

Carsten Adomeit