Zf Friedrichshafen Ag

Mannesmann Sachs Ag

Zf Sachs Ag

Volkswagen Ag

Dr. Ing. H.c. F. Porsche Aktiengesellschaft

Thomas John

Jochen Kuhstrebe

Axel Rohm

Rainer Reuthal

Hans-Jürgen Schneider

Olaf Moseler

Thomas Strasser

Wolfgang Grosspietsch

Wolfgang Kundermann

Jörg Sudau

Wolfgang Reisser

Eduard Steiner

Angelika Ebert

Andreas Dau

Markus Heiartz

Paul Kraus

Robert Seufert

Gerhard Gumpoltsberger

Markus Herrmann

Dieter Kraxner

Markus Terwart

Michael Ebenhoch

Thomas Wirth

Jens Dorfschmid

Alexander Hoffmann

Thomas Busold

Mario Bühner

Andreas Feiner

Rainer Brand

Markus Maier

Thomas Rauber

Hans-J&uuml;rgen Schneider

A method for operating a dual-clutch transmission with two clutches. During realization of a ratio, a first clutch is closed and a second clutch is open. During a ratio change, the first clutch is opened and the second clutch is closed. During a ratio change within short operating times, a target actuating pressure of the clutch for engagement is set to a fast-charging pressure level and subsequently adjusted to a closing pressure level, while a target actuating pressure of the clutch for disengagement is adjusted to an opening pressure level before setting the closing pressure level of the clutch for engagement. At least during a ratio change, an actual actuating pressure of the clutch for engagement is monitored and the target actuating pressure of the clutch for disengagement is adjusted to the opening pressure level if the actual actuating pressure of the clutch for engagement exceeds a pressure threshold.

Control method for a dual-clutch transmission

A method for disengaging a parking lock of a dual-clutch transmission of a motor vehicle with at least one drive unit is provided. The method includes, upon detection of an absolute value of a road inclination along a longitudinal axis of the motor vehicle exceeding a predetermined threshold and upon actuation of a selector lever for disengaging the parking lock prior to disengagement of the parking lock, issuing a torque request to the drive unit and closing a power-shifting clutch of the dual-clutch transmission with an engaged gear in a sub-transmission to which the power-shifting clutch is allocated. A torque transferred by the power-shifting clutch as a consequence of closing the power-shifting clutch and the torque request to the drive unit is a relief torque. The torque request to the drive unit and the closed power-shifting clutch are selected to counteract a torque, supported by a parking lock pawl, applying with an engaged parking lock by drive wheels on an output side at the transmission.

Dual-clutch transmission parking brake disengaging method of a vehicle

Method for shifting a neutral state of an automatic multi-stage transmission of a motor vehicle, where, to engage and to disengage gear stages of the transmission, shift couplings, at least one of which is equipped with a synchronizing device, can be actuated by a transmission actuator.

Method for shifting a neutral state of an automatic multi-stage transmission

A pressure medium-actuated control device of an automated step-by-step variable speed transmission. The device having a control valve for controlling an actively engaged disconnectable type clutch which is disposed along a power flow path between a motor and a transmission input shaft, and a self-retaining valve located in the pressure supply of the clutch control valve for a rotational speed-dependent emergency actuation of the disconnectable type clutch. An electrical switch-off actuator is connected to the self-retaining valve such that the valve piston, of the self-retaining valve, can be moved into an idle position to lock the pressure supply of the clutch control valve in a powered state of the switch-off actuator, and into an operating position determined by the applied control pressures in the power-off state of the switch-off actuator.

Pressure medium-actuated control device of an automated step-by-step variable speed transmission

A gearbox arrangement for a drive train of a motor vehicle, such as a double clutch gearbox arrangement or a power shift gearbox arrangement, has at least one group of gear-shifting elements () which can be actuated for engaging and disengaging at least one respective gear of the gearbox arrangement in that they are moved relative to a gearbox housing between at least one neutral position, in which no gear associated with the gear-shifting element is engaged, and at least one engaged-gear position, in which a gear associated with the gear-shifting element and the engaged-gear position is engaged. The arrangement according to the invention is characterised by at least one safety device () associated with the gear-shifting elements or with a group of gear-shifting elements, which takes a release position when all the gear-shifting elements are in their neutral position, and which can be moved from the release position to a safety position when one of the gear-shifting elements is moved into one of the engaged-gear positions, the safety device preventing the other gear-shifting elements from moving from their neutral position to an engaged-gear position.

Gear box arrangement with a gear-shifting element safety device for preventing the engagement of multiple gears of a gearbox

A motor vehicle includes a drive train having a drive unit, a gearbox having a first gearbox input shaft and a second gearbox input shaft, and a clutch having a first clutch device which is associated with the first gearbox input shaft, and a second clutch device which is associated with the second gearbox input shaft, for transferring torque between the drive unit and the gearbox. The first and second clutch devices are plate clutches to which an operating fluid, such as a cooling oil, is supplied to operate the same. The gearbox is associated with an actuator device and a control device for controlling the actuator device, the arrangement of which enables the gears associated with the first and second gearbox input shafts to be engaged and disengaged. The control device is designed such that at least one gear is automatically engaged by the actuator device, as a result of the clutch release of the vehicle.

Motor vehicle comprising a drive train having a multiple clutch drive

A dual clutch transmission with two clutches, two relative coaxial input shafts, two relative coaxial countershafts, two drive constants (gear trains, as well as one concentric transmission output shaft to the two drive shafts. Such a transmission structure is to be further embodied in such a way that through minor variations of gear mechanisms based on a construction module concept, seven-speed and eight-speed dual clutch transmissions with different direct gears, a different number of overdrive gears as well as different overall gear ratios can be manufactured. In accordance with a generic dual clutch transmission, the two countershafts by way of a coupling device can be rotationally connected with each other, and that on the countershaft embodied as hollow shaft, an idler gear is rotationally mounted, which meshes with a fixed gear on the transmission output shaft.

Double clutch transmission

A power train for a motor vehicle is configured with a control unit operable to increase or decrease the flow of operating fluid as a function of the instantaneous demand for the supply of the operating fluid to at least one of multiple clutch arrangements in such a way that the control unit decreases or interrupts the flow of operating fluid when the supply demand is low and increases the flow of operating fluid unit when the supply demand is high.

In either a pull-mode operating state or a push-mode operating state, a clutch arrangement assigned to the first gearbox input shaft and a clutch arrangement assigned to the second gearbox input shaft are actuated in such a way and a torque-generating arrangement comprising a drive unit is controlled in such a way that, when a shift is to be made between a first gear assigned to a first gearbox input shaft and a second gear assigned to a second gearbox input shaft, at least one of the following criteria with respect to the shifting sequence comprising the shift in question is fulfilled: (1) during the shifting sequence, the torque present at the gearbox output shaft is at least approximately constant or changes monotonically; (2) during the shifting sequence, the vehicle accelerates in an essentially monotonically increasing or in an essentially monotonically decreasing manner.

Method for the operation of a multiple clutching device and a power shift transmission

A clutch system includes a clutch device with at least one clutch arrangement for installation in a motor vehicle drive train between a drive unit and a transmission. The at least one clutch arrangement is actuated by a slave cylinder using a pressure medium which is supplied to the clutch device by a first pump. A further medium is also supplied to the clutch device by a second pump arrangement as an operating medium used during operation of the clutch device. The further medium is selectively supplied as a pressure medium to the slave cylinder.

Clutch system

A clutch operator arrangement for introducing an actuating force into a friction clutch includes a ball screw arrangement.

Clutch operator arrangement

A ball screw includes a spindle element which has a first groove arrangement on an outer circumferential surface, a nut element which surrounds the spindle element and has a second groove arrangement on an inner circumferential surface, and a plurality of balls, at least some of which engage into the first groove arrangement and the second groove arrangement. The nut element is rotatable about an axis of rotation with respect to the spindle element, and, during the rotation of the nut element about the axis of rotation with respect to the spindle element, the balls which engage into the first groove arrangement and the second groove arrangement roll in the first and the second groove arrangement, while at the same time rotate about respective ball axes of rotation. In this case, there is provision, with respect to the ball axis of rotation, for an effective ball rolling radius with which the balls roll in the first groove arrangement to be smaller than the effective ball rolling radius with which the balls roll in the second groove arrangement.

Ball screw

An actuating element for a clutch includes a stop which is adjustable by an automatic adjusting device for ensuring that the actuating stroke of a piston increases in the releasing direction of the clutch and that the actuating stroke is displaced away from the clutch in response to wear of the clutch linings when the clutch is engaged.

Actuating element for a clutch actuated by pressure medium

An actuating drive for actuating a friction clutch and an automated shift transmission, having valve units which enable a switching operation, on the one hand, of the friction clutch, and on the other hand, of the shift transmission. It is possible for a change to the switching state at the friction clutch to be triggered by a gear selection device. The valve unit that is assigned to the friction clutch is assigned a switching device which has a link between the actuating cylinder for the slot selection and the hydraulic circuit that is connected to the actuating cylinder for actuating the friction clutch and enables the driving, as required, of one or the other actuating cylinder.

Growing community of inventors

Sulzheim, Germany

Thomas John