Zf Friedrichshafen Ag

Martin Miller

Josef Bader

Mario Steinborn

Bernd Doebele

Thomas Hafen

Andreas Graf

Rainer Petzold

Franz Bitzer

Karl-Fritz Heinzelmann

Peter Herter

Jochen Breuer

Gerhard Höring

Bernd Lutz

Gerhard Hoering

Jürgen Rauter

Johannes Ehrminger

Bernd Woelfle

A detent device for a transmission, having a shifting element, first and second end-position retaining configurations arranged at first and second positions, respectively on the shifting element, the second position is different from the first, and a neutral retaining configuration arranged on the shifting element at a third position different from the first and second positions. A latching first detent element which, depending on the position of the shifting element, latches either at the first or second end positions in the first or second end-position retaining configurations, respectively, and another latching detent element, which latches in the neutral retaining configuration when the shifting element is in its neutral position. The neutral retaining configuration has a retaining contour which is designed and/or orientated differently on the shifting element from the first end-position retaining configuration and from the second end-position retaining configuration. A transmission with a detent device.

Detent device and transmission

An arrangement of a shift rocker (), in a transmission housing, comprising a sliding sleeve () and a shift rod (). The shift rocker () is mounted to pivot relative to the housing about a pivot axis, can be actuated by the shift rod (), and engages with an annular groove of the sliding sleeve (), via sliding blocks (). The pivot axis of the shift rocker is substantially vertically orientated and the shift rocker () has at least one supporting element (), located outside the vertically orientated pivot axis, which rests on the shift rod ().

Arrangement of a gear shift fork in a transmission

A method of operating a drivetrain of a motor vehicle. The drivetrain comprises a transmission arranged between a drive assembly and an axle drive, such that an input shaft of the transmission is connected, via a controllable separator clutch, to the drive assembly and an output shaft of the transmission is connected to the axle drive, and such that the transmission comprises at least one shifting element formed as a claw clutch. To reduce the probability that a tooth-on-tooth position may occur in a shifting element formed as a claw clutch, a torque is applied thereto by at least one transmission-internal assembly and/or at least one transmission-external assembly so that a speed difference at the claw clutch approaches a predetermined nominal value, and engagement of the claw clutch is only started when the speed difference of the claw clutch reaches the nominal value.

Method for operating a drive train

An automated group transmission having a multi-stage main transmission (HG), a splitter group (VG) connected upstream from the main transmission (HG) and a two-stage range-change group (BG) connected downstream of the main transmission (HG), such that the splitter group (VG) is connected, via a controllable separator clutch, to a drive motor. The main transmission (HG) and the range-change group (BG) are of either a synchronized or an unsynchronized design and the shifting clutches of two respective transmission ratio steps, in at least one of the partial-transmissions (VG, HG, BG), are respectively combined in a common shifting packet with two shift positions and a neutral position. To speed up most range shifts, it is provided that in the main transmission (HG) the shifting clutches associated with the lowest transmission ratio step (G) and with the highest transmission ratio step (Gor G) are combined in a common shifting packet (Sor S).

Automatic group transmission

A clutch system for producing and interrupting a force flow between the engine and transmission of a motor vehicle, with a clutch, which is disengaged unless actuated, and one or more valves, which regulate the flow of pressure medium and which are electrically actuated by a control and regulation unit. If there is electrical failure while driving and when a gear is engaged or when the vehicle is stationary, the engine is running and a transmission gear is engaged, unintended clutch engagement is prevented. The valves are designed such that if there is a failure of the voltage supply and consequently also of the actuation of the valves by the electronic control and regulation system, the operating condition of the clutch existing at the time of failure, namely the disengaged or engaged operating condition, remains as it is.

Clutch system

A method for controlling shifts in an automated group transmission that comprises a multi-stage main transmission, a multi-stage splitter group connected upstream from the main transmission and a multi-stage range-change group connected downstream from the main transmission. The method includes the steps of disengaging the separator clutch to relieve the load of the motor; shifting range-change group to neutral and bringing the speed of the motor to the synchronous speed of the target gear; braking the main transmission and the splitter or upstream group via a transmission brake; changing the transmission ratios in the main transmission and in the splitter group; synchronizing the range-change group by partially engaging the separator clutch; engaging the desired transmission ratio in the range-change group; and simultaneously increasing the load on the drive motor and fully engaging the separator clutch.

Shift control method for an automatic group transmission

A method for controlling an automated friction clutch arranged in a drive train of a motor vehicle in the force flow between a drive engine () and a drive transmission (), which is configured to close passively by spring pressure and can be disengaged and engaged by way of a pressure-medium-actuated clutch actuator (), such that the actuation position x_K of the clutch actuator () or of an associated transmission element is determined and used for controlling the friction clutch (). To improve the accuracy and reliability of the clutch actuation it is provided that in addition, an actuating pressure p_K of the clutch actuator () is determined and that a required change of the clutch torque M_K to a new nominal value M_K_soll takes place under pressure control, in that the actuating pressure p_K of the clutch actuator () is set to a nominal value p_K_soll which corresponds to the nominal value M_K_soll of the clutch torque M_K.

Method for controlling an automated friction clutch

A method for controlling an actuating device in an automated shifting system of a motor vehicle. The position of the actuating device is determined by a path measurement system. The actuating device can be controlled by a pressure regulation device, including a pressure medium reservoir, at least two pressure lines and a switching valve for connecting a first pressure line to a pressure medium line leading to the pressure chamber of the actuating device, and a pressure regulating device for adapting the pressure level of the main pressure line to the control pressure level of the actuating device. By appropriately controlling the pressure regulation device before the piston of the actuating device moves in the intended direction, it is moved in the direction opposite to the intended movement direction. When this movement direction is registered the movement direction is changed to the intended movement direction.

Method for activating an actuating means

A method for shifting an automated transmission situated in a drive train of a motor vehicle between an engine and a drive axle and having at least one multi-speed main transmission and a two-speed range change group rear-mounted thereon. The main transmission has at least one counter shaft with a transmission brake. A clutch engages the prime mover and the main transmission and the range change group is shifted via unsynchronized dog clutches which are combined in pairs in a common shift set and have two shift positions and one neutral position such that, during a range change gear shift both in the main transmission and the range change group a change between two ratio stages occurs. A range change up-shift includes synchronizing the input shaft and the target gear utilizing the transmission brake and passively synchronizing the dog shifted transmission parts by the edge beveling of the concerned dog clutches.

Method for shifting actuation of an automated group transmission

A method for shifting an automated transmission situated in a drive train of a motor vehicle between an engine and a drive axle and having at least one multi-speed main transmission and a two-speed range change group rear-mounted thereon. The main transmission has at least one counter-shaft with an transmission brake. A clutch engages the prime mover and the main transmission and the range change group is shifted via unsynchronized dog clutches, which are combined in pairs in a common shift set having two shift positions and one neutral position such that during a range change gearshift, both in the main transmission and in the range change group, a change between two ratio stages occurs. A range change up-shift and down-shift each include active synchronization of the dog clutch by way of the transmission brake and of the separating clutch.

Method for shifting actuation of an automated transmission

A method for actuating a shift cylinder () of an electro-pneumatic control unit for the gearbox of a motor vehicle. The gearbox comprising a main gearbox, a group gearbox or other shifting elements with detents in at least one of a neutral position and/or a final position(s). The shift cylinder () is prefilled with a pressure below the detent actuating force, prior to a gearshift phase of the control unit, such that the gearshift time is reduced.

Method for operation of a selector cylinder of an electro-pneumatic selector unit for a motor vehicle gearbox

In a shifting unit () for a vehicle transmission gearbox, the switching unit comprising valves which are connected between with one another by a pressure supply line conduit () and by a pressure exhaust line () associated with a switch chamber () of a switch cylinder (). The switch chamber () of switch cylinder () has exhibits at least one opening valve () and at least one closing valve () through additional valves (); and the pressure supply line () and the pressure exhaust line () are separately closed, opened, blocked and/or swapped.

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Immenstaad, Germany

Martin Miller