Zf Friedrichshafen Ag

Otto Ebner

Marcus Gansohr

Christoph Rüchardt

Klaus Schweiger

Andreas Schwenger

Matthias Winkel

Thomas Knoblauch

Thomas Jäger

Florian Schneider

A method and a apparatus for operating an automatic synchronized transmission for motor vehicles. The transmission having a countershaft design, with a countershaft parallel to input and an output shafts, which communicate with each other and the countershaft by means of gear wheel pairs. The transmission further having at least one coupling and synchronization device for at least one idler gear, with the aid of which at least one idler gear can be rotationally fixed to a transmission shaft, such that when the motor vehicle is stationary and a starting gear is engaged, torque of the countershaft is not drive-effectively reduced. Thus, ensuring that when the starting gear is engaged, no undesired acceleration of the vehicle occurs.

Placing an automatic synchronized transmission into a starting speed

A method is proposed for determining a clutch application point in a transmission of a vehicle having a spring-actuated clutch system in which the clutch application point is adapted according to at least one adequate regulated quantity of the clutch system.

Method for determining the clutch application point

A known device for increasing the functional reliability for a hydraulic circuit of a hydraulic clutch having a pressure reservoir () and a release cylinder () which comprises a primary piston () and a secondary piston (). A compensation volume is developed in the sense that when the vehicle is at a standstill and the parking brake released, an unintentional release of the clutch is prevented. A pressure-monitoring/pressure-supply device () is used for determining a reference operating pressure and establishes a static pressure which, in case of any system error, only allows displacement of the secondary piston () such that the contact pressure of the clutch discs, against one another, is still sufficient to maintain the vehicle at a standstill.

Device for increasing the functional reliability of a hydraulic circuit of a hydraulically operable clutch

A method for clutch actuation at low temperatures for a motor vehicle having a hydraulically actuatable clutch, below a predetermined temperature a situation-dependent pre-opening of the clutch is executed when a braking is probable.

Method for actuating a clutch at low temperatures

A device for rendering a hydraulic actuating device operational. A motor vehicle clutch with an emitter-receiver system located in the transmission path of the actuating device comprising two pistons whose positions, relative to one another, can vary as a function of the desired operating behavior of the actuating device and is developed further such that in relation to the emitter-receiver system that is to be filled with fluid, operationality can be established comparatively quickly and by simple way. A fluid supply unit () comprises one impulse valve () that serves to release an essentially constant volume flow, acted upon by an impulse valve control device () which is constructed such that the fluid volume flow released by the fluid supply unit () and flowing into the emitter-receiver system () does not exceed a limiting volume flow Q.

Device for rendering operational a hydraulic actuating device

An operating time is determined by an approximation method within the scope of the method for determining the actual operating time of a hydraulic, electrohydraulic or electric component of a motor vehicle or of a working machine within a reference time or a monitoring period.

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Friedrichshafen, Germany

Otto Ebner