Zf Friedrichshafen Ag

Luk Lamellen Und Kupplungsbau Beteiligungs Kg

Luk Lamellen Und Kupplungsbau Gmbh

Anton Fritzer

Thilo Schmidt

Markus Herrmann

Stefan Beck

Johannes Kaltenbach

Peter Ziemer

Matthias Reisch

Martin Brehmer

Wolfgang Rieger

Michael Wechs

Georg Gierer

Michael Reuschel

Matthias Horn

Jens Moraw

Thomas Rosemeier

Gerhard Niederbrucker

Raffael Kuberczyk

Viktor Warth

Franz Bitzer

Tobias Pfleger

Hans-Joachim Martin

Bernd Unseld

Martin Rattay

Lara Ruth Turner

Suryanto Hendrawan

Michael Roske

Juri Pawlakowitsch

Max Bachmann

Rainer Eidloth

Carsten Weinhold

Wolfgang Reik

Christian Popp

Martin Vornehm

Bernhard Walter

Andreas Schmidt

Andreas Deimel

Thomas Lemp

Tobias Zollner

Mario Hasel

Oliver Bayer

Christoph Köhler

Jonas Knör

Georg Ege

Derk Langenkaemper

Valentine Vincent

Patrick Peter

Michael Miller

Jakob Mayer

Ulrich Mair

Florian Mayer

Adolf Bucher

Alexander Pfau

Hans-Ulrich Nonnast

Joost Peeters

Hans-J&uuml;rgen Renk

Felix Klünder

Andreas Abele

Harald Mueller

Stefan Gierer

Tobias Zöllner

Christian Hunger

Fabian Schöniger

A vehicle transmission includes a hydraulic circuit and a control unit. The control unit is configured to: obtain () a target pressure specification; convert () the target pressure specification into a target volume flow rate; determine () a valve volume flow rate as a function of the target volume flow rate and as a function of parameters that represent system properties of the hydraulic circuit; determine () a pressure drop at a valve due to flow forces as a function of the valve volume flow rate; determine () a compensated valve output pressure as a function of the valve volume flow rate and the pressure drop; determine () the electric control current as a function of the compensated valve output pressure; and activate a valve with the electric control current.

Method for the open-loop control of an electrically controllable valve in a vehicle transmission

A transmission (G) includes an input shaft (GW), an output shaft (GW), an electric machine (EM), a plurality of planetary gear sets (P-PP-P), and gear-implementing shift elements (S-SS-S). Via engagement of a first of the gear-implementing shift elements (SS), which is a force-locking shift element having a variable torque transmission capacity, the input shaft (GW) and an element (EE) of one of the planetary gear sets (PP) can be brought into a fixed rotational speed relationship with respect to each other. Another element (EEE) of one of the planetary gear sets (PPP) is permanently connected to a rotor (R) of the electric machine (EM). By engaging an auxiliary shift element (ZS,ZSa,ZSb), which is a form-locking shift element, the rotor (R) and the input shaft (GW) can be brought into a fixed rotational speed relationship with respect to each other.

Transmission for a motor vehicle, drive train and method for operating a transmission

A transmission for a motor vehicle wherein the drive shaft (An) is rotationally fixedly connectable by the first shift element (K) to the first shaft () and by the second shift element (K) to the second shaft (). The second shaft () is rotationally fixedly connectable by the fifth shift element (B) to the housing (). The third shaft () is rotationally fixedly connected to the third gear set element of the second planetary gear set (RS) and to the first gear set element of the third planetary gear set and is rotationally fixedly connectable by the sixth shift element (B) to the housing (). The second gear set element of the third planetary gear set (RS) is rotationally fixedly connected to the output shaft (Ab), and the third gear set element of the third planetary gear set (RS) is rotationally fixedly connected to the second shaft ().

Vehicle transmission

A transmission for a motor vehicle wherein the drive shaft (An) is rotationally fixedly connectable by the first shift element (K) to the first shaft () and the first shaft is rotationally fixedly connectable by the second shift element (B) to the housing (). A sun gear of the first planetary gear set (RS) is rotationally fixedly connectable by the third shift element (K) to the drive shaft (An). A carrier of the first planetary gear set (RS) is rotationally fixedly connected to the output shaft (Ab) and to a ring gear of the second planetary gear set (RS). A ring gear of the first planetary gear set (RS) is rotationally fixedly connected to the second shaft (), wherein the second shaft () is rotationally fixedly connectable by the fourth shift element (B) to the housing ().

A method for operating a drive train of a motor vehicle includes closing a frictional-locking shift element that serves as a starting element of a transmission in a slipping manner such that slip at the frictional-locking shift element is reduced by a defined pressure control of the frictional-locking shift element, determining a differential rotational speed at the frictional-locking shift element or a variable dependent on the differential rotational speed while the frictional-locking shift element is closing, and, when the differential rotational speed or the variable dependent on the differential rotational speed is less than a first limit value or reaches the first limit value, changing a rotational speed of the drive unit in such a manner that the differential rotational speed or the variable dependent on the differential rotational speed becomes less than a second limit value or reaches the second limit value within a defined time period.

Method and control unit to control a drivetrain

A method of operating a vehicle hybrid drive-train in which, depending on the operating situation, the engine and electric machine either operate individually or together. The engine and the electric machine can be coupled or separated by a clutch. The engine can be started by the electric machine or a separate starting device. To co-ordinate transmission shifts and required engine starts, during a transmission shifting process, if the engine needs to be started, then based on whether the shift is an upshift, a downshift, a traction shift or an overdrive shift and also depending on the type of engine start required, it is first determined whether the shift should be completed, at least partially completed or discontinued before carrying out the start and, based on this determination, measures for continuing, at least partially continuing or discontinuing the shift process are initiated.

Method for operating a hybrid drive train of a vehicle

A multi-disk shifting element of a motor vehicle transmission, which includes a plurality of outer disks () and a plurality of lining disks () which, when viewed axially, are arranged in alternation one after another. The outer disks include a number of flat outer disks (AL) and a number of corrugated outer disks (AL, AL).

Multidisk shifting element

A pressure medium supply device of a hydraulically actuated shifting element (K, K) comprises at least one pressure medium supply duct () in communication with a pump () and a line () for pre-filling of the shifting element. An additional pressure-retaining valve () or a check diaphragm is integrated in the pressure medium supply duct (), between the shifting element and the shifting element valve (), and can be closed in the draining direction of the pressure medium supply duct (). The pressure-retaining valve () is designed such that the shifting element can be drained and the pressure medium supply device can be vented.

Pressure medium supply device of a hydraulically actuated shifting element

A hydraulic control system for controlling a variable fluid volume flow to a consumer (), for example a flow of cooling oil to a wet-operating clutch, with a hydraulically pilot-controlled control valve connected to a fluid supply. The first control valve () is designed such that, in the absence of any pilot control pressure (pVST), the valve delivers a specified initial volume flow (Q) and, as the variable pilot control pressure (pVST) increases, the valve delivers a continuously increasing volume flow (Q). At least one second, independent, also hydraulically pilot-controlled valve () is designed such that this valve is activated in a specified range () of the variable pilot control pressure (pVST).

Hydraulic control arrangement for controlling a variable fluid volume flow

A hydraulic control device with a plurality of gear-actuating cylinders for engaging and disengaging the gears of an automated multi-step transmission, with pressure-controlled gear-regulating valves for controlling the pressure in one pressure chamber of the cylinders, and with a multiplex arrangement of singly switchable pressure-controlled selector valves for assigning the regulating valves to one pressure chamber of the actuating cylinders. The device includes a common pilot valve, designed as a regulating valve, for actuating one of the regulating valves and at least one of the selector valves. The pilot valve features a first control pressure range that contains the switching pressure of the selector valve and a second control pressure range that contains the regulating range of the gear-regulating valve.

Hydraulic control apparatus of an automated multi-step change-speed gearbox

A method for emergency actuation of an automated dual-clutch transmission of a vehicle with electrohydraulic control via a transmission control device. The method includes disengaging one clutch of the dual-clutch transmission, in order to realize emergency operation of the transmission and applying pressure on the other clutch after an error signal is transmitted indicating a malfunction of the transmission and/or the transmission control device. In order to keep the complexity of the hardware of the hydraulic system low, both clutches are disengaged, when an error signal occurs, and adjusted to a safe initial state, and an actuating pressure is only re-applied to one of the two clutches after the initial state is reached. In addition to the already existing elements of the hydraulic system, only one device or software is required which detects and selects the clutch that is more advantageous for continued driving operation.

Method for the emergency actuation of an automated double clutch transmission of a motor vehicle

A bypass valve for a cooler connected downstream from a hydraulic aggregate. The bypass valve includes a housing with ports for connection to the hydraulic aggregate and the cooler. A closure element is located in the housing for closing and opening a bypass. A spring pushes the closure element into a closing position, and thermo-sensitive means causes the closure element to open if the temperature of the hydraulic fluid is below a threshold temperature. The thermo-sensitive means are formed by the valve spring, which is made of a memory-metal alloy with a transition point close to the threshold temperature such that below the threshold temperature it no longer exerts a force and allows the closure element to open.

Bypass valve for a cooler connected downstream of a hydraulic unit

A temperature sensor arrangement in an automatic transmission in which the temperature sensor () is arranged such that oil leaked from the hydraulic system permanently flows around it.

Temperature sensor arrangement in an automatic gearbox

A bypass valve for blocking oil flow through a radiator from a transmission with low oil temperatures includes an oil supply from the radiator, an oil supply, via a bypass line, an oil outlet and a valve unit arranged inside the valve housing. The valve unit includes a compression spring and a heat sensitive element, which move depending on the oil temperature such that when the temperature falls below a threshold value, the oil supply from the radiator is closed and the supply, via a bypass line, is opened. When the oil temperature rises above the threshold value, the oil supply from the radiator is opened and the supply, via the bypass line, is closed. The valve unit can be axially moved against the force of the compression spring, when a predefined oil pressure is reached, thus opening the supply, via the bypass line.

Device for uncoupling the oil flow through a radiator

A control valve arrangement having a clutch regulation valve (), which pressurizes a device to actuate the clutch, and a valve that produces a controlled pilot pressure (P_VST). An electronic control unit (ECU) controls a valve to supply a control valve with the pressure (P_VST). The arrangement further having a hydraulic system which, if the ECU fails and the pressure (P_VST) ceases, the last shift condition of the clutch actuation device, prior to the ECU failure, can be maintained in an emergency. The arrangement includes a valve, which delivers an activation pressure (P_A), depending on an engine-speed-dependent control pressure (P_D), to an actuation valve (), which then delivers the pressure (P_A) to the valve () to prevent the emergency function initiation despite a lack of pressure (P_VST) and existence of the pressure (P_D) sufficiently high to initiate the emergency function.

Control valve arrangement for controlling a starting clutch of an automatic transmission

Growing community of inventors

Markdorf, Germany

Anton Fritzer