Zf Friedrichshafen Ag

Zahnradfabrik Friedrichshafen, Ag.

Zf Freidrichshafen Ag

Georg Gierer

Thilo Schmidt

Christian Popp

Klaus Steinhauser

Peter Schiele

Markus Herrmann

Anton Fritzer

Karlheinz Mayr

Bernd Allgaier

Hubert Remmlinger

Herbert Kiebler

Uwe R&uuml;hringer

Peter Ziemer

Josef Haupt

Gert Bauknecht

Wolfgang Schmid

Markus Moosmann

Christian Schwemer

Wolfgang Runge

Eberhard Biermann

Willy Holdenried

Tobias Rolser

Walter Frei

Horst Furtner

Hubert Friedrich

Ralph Böhm

J&uuml;rgen Mittelberger

Harald Deiss

Thomas Lindner

Stefan Meschenmoser

Eugen Gerteiser

Ruben Cüppers

Uwe Ruhringer

Wolfgang Wiest

A transmission device has at least one electro-hydraulic transmission control unit and a method of operating the transmission device having a plurality of gear wheel that can be engaged and disengaged from a force flow by fluidically actuated shifting elements. A piston space of a first shifting element, delimited by a second functional surface of the actuating piston of the first shifting element, is made separate from a piston space of a second shifting element, delimited by the first functional surface of the actuating piston, and an area of the second shifting element, that carries an actuating pressure, or an area of the first shifting element, that carries an actuating pressure, is, or can be, connected to the piston space delimited by the second functional surface of the actuating piston of the first shifting element.

Transmission device and method for operating a transmission device

A hydraulic transmission unit comprises at least one pressure regulation valve () and a pilot control valve () which is connected to the pressure regulation valve () by a pilot control line (). A pre-filling valve () sets a pre-filling pressure (p) to avoid draining of a clutch () and the lines () connected to the clutch () in an operating condition in which the clutch () is not actuated. To avoid draining when the clutch when in the operating condition, the pilot control line () is also connected to at least one line () which is pressurized with a second pre-filling pressure (p).

Hydraulic transmission control

An actuating device for a shift element of a transmission which is acted upon by a hydraulic actuating pressure (p_B) and comprises a valve device. To vary the actuating pressure (p_B), the valve device is acted upon by a control pressure (p_EDS) in an area of active surfaces (A, A) of at least a first and a second valve slides. An active surface (A) of the first valve slide (A) is acted upon by a hydraulic pressure (p_B) which is equivalent to the actuating pressure (p_B), acts in opposition to the control pressure (p_EDS) and can be adjusted as a function of the control pressure (p_EDS) applied, such that a smaller variation of the actuating pressure (p_B) results from a change of the control pressure (p_EDS) within a first pressure range of the control pressure (p_EDS) than within a second pressure range of the control pressure (p_EDS).

Actuating device for a shift element of a transmission device which can be applied with an actuating pressure

A transmission oil pump for an automatic transmission of a motor vehicle. The speed of the oil pump can be shifted by a transmission (), that is arranged between the drive motor of the motor vehicle and the transmission oil pump, to a fast-running mode or a slow-running mode so that the oil pump can be operated at two different speed levels.

Oil pump for an automatic transmission and control method thereto

A process for monitoring a direction of drive from an automatic or automated vehicle transmission at near-zero vehicle speed via an engaged gear. A desired direction of drive of the transmission is determined from an engaged gear at the time the vehicle begins motion. An actual direction of drive is determined from the transmission and if different from the desired direction of drive, an error signal is produced. The process including determining the actual drive either from a sensed rotational direction of a transmission input shaft and a sensed rotational direction of a transmission output shaft or a sensed valve setting, a sensed pressure in an transmission electro-hydraulic control system or on a transmission shifting element or from a sensed direction of rotation of a transmission gearset element or from axial movement or force of a transmission constructional element.

Process for monitoring the direction of frictional drive from a vehicle transmission at near-zero vehicle speed

A method for monitoring frictional engagement in an automatic or automated motor vehicle transmission having a hydrodynamic starter element when the transmission is in a preset neutral or parking position and the automatic or automated motor vehicle transmission controlled by this method. When the motor vehicle is at or close to a standstill in a preset neutral or parking position, the current transmission rotational input speed and a current engine rotational speed of the drive motor are determined and based on the speed ratio between the current transmission rotational input speed and the current engine rotational speed an error is found to be present if the speed ratio is less than a predefined threshold value, which is less than/equal to 1.

Motor vehicle transmission and method for monitoring frictional engagement in same in a preset neutral or parking position

A process of monitoring a drive direction of an automatic or automated vehicle transmission at near-zero vehicle speed via an engaged gear. A desired direction of drive of the transmission is determined from an engaged gear at the time the vehicle begins motion. An actual direction of drive is determined from the transmission and, if different from the desired direction of drive, an error signal is produced. The process includes determining the actual drive either from a sensed rotational direction of a transmission input shaft and a sensed rotational direction of a transmission output shaft or a sensed valve setting, a sensed pressure in an transmission electro-hydraulic control system or on a transmission shifting element or from a sensed direction of rotation of a transmission gearset element or from axial movement or force of a transmission constructional element.

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

An electrohydraulic control device () of an 8-speed transmission having several electrically controllable pressure control valves (-) for hydraulically actuating five switching elements (A-E) and an electric gear control unit via which different operating states of the transmission may be adjusted. Three of the switching elements are connected in the force flow of the transmission for representing a gear ratio ('1' to 'R') of the transmission. When the gear control unit is de-activated and the power supply to the solenoid valve and pressure control valves is interrupted, and when the transmission is in the operating state, in which a gear ratio (&#x201c;1&#x201d;; &#x201c;2&#x201d;; &#x201c;3&#x201d;; &#x201c;4&#x201d;; &#x201c;5&#x201d;; &#x201c;6&#x201d;; &#x201c;7&#x201d;; &#x201c;8&#x201d;; &#x201c;R&#x201d;) is engaged, a predefined emergency transmission (&#x201c;6&#x201d;; &#x201c;R&#x201d;) is represented by three simultaneously hydraulically connected switching elements (C, D, E, A, B, D).

Electroyhydraulic control device of a gear unit

An electrohydraulic transmission controller (), a transmission device with an electrohydraulic transmission controller and a vehicle drive train that features an electrohydraulic transmission controller are disclosed. The electrohydraulic transmission controller is constructed with a plurality of electrically actuatable pressure control valves (to), as well as with a plurality of valve arrangements (to) that can be acted on in each case by an hydraulic precontrol pressure depending upon the actuation of the pressure valves, by way of which valve arrangements switching elements (A to E) of a transmission device can be acted on in each case with a control pressure to produce a required operating state of the transmission device. An additional pressure control valve () is provided to adjust a precontrol pressure (p_VS) of an additional valve arrangement (), whereby downstream of the additional valve arrangement, the sub-assembly () of a vehicle drive train can be acted on by a cooling oil volume flow subject to the precontrol pressure of the additional valve arrangement and an operating state of the additional valve arrangement () corresponding to it.

Electrohydraulic transmission controller, transmission device, and a motor vehicle drive train

A device for controlling a hydraulically operable switching element () of an automatic transmission of a vehicle with a position valve mechanism () having a main switch piston () which is spring biased into a first switch position and a second switch position with a pilot pressure (P_MV) which is adjustable through an electrically operated actuator (). An additional switch piston () and the main switch piston () are axially actuated in a valve housing (). Depending on the position of the pistons (), faces (A,A) of the respective pistons are either spaced apart or adjacent. The additional switch piston () is adjustable depending on a pilot pressure (p_K) of a switching element which engages a gear for forward drive.

Device for the control at least of a hydraulically operable switching element of an automatic transmission

Description of a hydraulic control system (A) for a hydrodynamic torque converter () with a controlled torque converter lockup clutch () of an automatic transmission for controlling a supply pressure (p_WD_zu) of the torque converter () and a supply pressure (p_WK_zu) of the torque converter lockup clutch (). The torque converter lockup clutch () is engaged when the supply pressure (p_WD_zu) of the torque converter () is lower than a predefined pressure level of the supply pressure (p_WK_zu) of the torque converter lockup clutch. A converter pressure valve (WDV) is provided for controlling the supply pressure (p_WD_zu) of the torque converter (), and a converter coupling valve (WKV) for controlling the supply pressure (p_WK_zu) of the torque converter lockup clutch, where their valve slides (WDV_S, WKV_S) can be acted upon by at least one pre-control pressure (p_VS) and one system pressure (p_sys). When the torque converter lockup clutch () is disengaged, the valve slide (WKV_S) of the converter coupling valve (WKV) is acted upon in such a way on an active surface () by the reverse pressure (p_WD_ab) of the torque converter (), and when the torque converter lockup clutch () is engaged, is acted upon in such a way on the active surface () by the reverse pressure (p_WK_zu) of the torque converter lockup clutch (), that at least either the supply pressure (p_WD_zu) of the torque converter () or the supply pressure (p_WK_zu) of the torque converter lockup clutch () is higher than a predefined pressure level (p) over the entire operational area of the torque converter ().

Hydraulic control system for a hydrodynamic torque converter comprising a controlled torque converter lockup clutch

An automatic transmission control device with a hydraulic control system controlled by an electric transmission control device. The system including several pressure control valves, actuated electrically by the transmission control device, and several switching valves and pressure regulation valves, actuated by hydraulic pilot pressure, which is adjustable with the pressure control valves. Each shift element is associated with one of the pressure control valve. An engagement prevention valve is actuated by one of a control pressure of the first shift element and a pressure signal equivalent to the control pressure of the first shift element to engage the reverse drive gear. A pressure supply line of the second shift element for obtaining the reversing gear is blocked when the engagement prevention valve is in its first switch position and open when the engagement prevention valve is in its second switch position.

Gear control device

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

A valve assembly for controlling actuation of at least one starting clutch of an automatic transmission includes at least one clutch control valve through which a supply pressure is directed to a clutch actuation device, a pressure control valve controlled by a control device to supply at least one control valve of the valve assembly with a pilot pressure, a self-maintained hydraulic unit to maintain operation of an engaged starting clutch upon failure of the control device and loss of the pilot pressure. The valve assembly has a self-maintained valve and an activation valve. The self-maintained valve directs an activation pressure or control pressure, depending on the engine or transmission speed, to the activation valve. The actuation valve directs the activation to at least one clutch-regulating valve. The valve assembly also controls actuation or de-activation of the emergency operation function with a clutch actuation pressure.

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Kressbronn, Germany

Georg Gierer