Zf Friedrichshafen Ag

Thomas Kurz

Hans Hofler

Andreas Schwarz

Sven Bieber

Hans Höfler

A method for calibrating an actuation of a converter lock-up clutch of a hydrodynamic torque converter having a pump wheel and a turbine wheel connected to a power-split transmission. The transmission has at least two clutches each connected to a respective power-split shaft assembly and each configured be actuated separately to close and open in order to apply a clutch torque to the turbine wheel so that a rotation speed difference between the pump wheel and the turbine wheel changes. The method includes opening the converter lock-up clutch and the at least two clutches each connected to a respective power-split shaft assembly of the transmission, rotating the pump wheel with a specified rotation speed, and applying a clutch torque to the turbine wheel as a function of an actual rotation speed difference. Clutches connected to a different respective power-split shaft assembly of the transmission are actuated in the closing direction.

Control method for calibrating an actuation of a converter lock-up clutch of a hydrodynamic torque converter

A method for holding a vehicle on a gradient. The vehicle has a transmission with an output, a first clutch and a second clutch. The primary sides of the first and second clutches are mechanically operatively connected to one another. The secondary sides of the first and second clutches are mechanically operatively connected to one another and to the output of the transmission. Different transmission ratios can be engaged by way of the first clutch and the second clutch, and the first clutch is in an engaged state. The method includes the additional closure of the second clutch in order to block the transmission and thus hold the vehicle at a standstill on a gradient.

Method for holding a vehicle on a gradient

A method of shifting a transmission in which a clutch, located in the torque flow, in a first gear and in a second gear is controlled in such manner that, in the first gear, the clutch slips and transmits a first torque and, in the second gear, the clutch slips and transmits a second torque. The second torque is chosen such that an output torque of the transmission remains the same when shifting from the first gear to the second gear.

Smooth gear change during inching

A control unit () that outputs a shift signal to a transmission () when the control unit recognizes that the bucket () is in a loading position, such that the transmission () shifts not to the next-higher gear ratio, but to a further, even higher, gear ratio.

Method for operating a transmission

A method for controlling the transmission of a working machine, by which, with at least one sensor of the working machine, at least one specific parameter is determined and transmitted to a control unit for controlling the transmission. The working machine has a lifting mechanism and the at least one specific parameter which characterizes an actuation condition of the lifting mechanism. A predetermined shifting strategy is adapted, by the method, as a function of the at least one specific parameter.

Method and device for controlling a transmission of a working machine

A rotational speed-regulated internal combustion engine in a working machine, for example a wheel loader, shortly before the engaging a bridging clutch of a hydrodynamic torque converter, is switched over in such manner that the internal combustion engine operates under torque regulation when the bridging clutch of the hydrodynamic torque converter is engaged.

Method for operating a drive train

During reversal of drive of a vehicle, particularly a work machine with a hydrodynamic torque converter and a bypass clutch, the bypass clutch is first disengaged, during the reversal process. Next, a previously engaged first driving direction clutch, driving the vehicle in the first driving direction, is disengaged and a second driving direction clutch, for driving the vehicle in the second driving direction, is engaged so that a speed of the vehicle, in the first driving direction, is reduced and a speed of the vehicle, in the second driving direction, is subsequently accelerated, whereby the drive motor is operated at a higher rotational speed during the reversal process.

Method for reversing the direction of travel of a vehicle

A method of actuating a clutch of a hydrodynamic torque converter in a self-propelling working machine such that when the clutch is engaged and thereby connects a drive input of the hydrodynamic torque converter to a drive output of the hydrodynamic torque converter, and when a service brake is actuated, the clutch is disengaged thereby separating a drive input of the hydrodynamic torque converter from a drive output of the hydrodynamic torque converter. The method comprises the steps of, when the service brake is actuated, actuating the clutch in the engaging direction, and maintaining engagement of the clutch if a device for recognizing a driving status of the working machine detects that the working machine is driving downhill.

Method for actuating a clutch of a hydrodynamic torque converter

A clutch of a hydrodynamic torque converter, which connects the drive input of the hydrodynamic torque converter to the drive output of the hydrodynamic torque converter, is actuated in a disengaging direction when a power at an auxiliary power take-off in a vehicle exceeds a predefined value.

Method for the operation of a clutch of a hydrodynamic torque converter

A clutch of a hydrodynamic torque converter in which the input drive of the hydrodynamic torque converter can be connected to the output drive of the hydrodynamic torque converter. The clutch of the hydrodynamic torque converter is only engaged if a difference between the rotational speeds of the pump and the turbine of the hydrodynamic torque converter is not reached and a predefined distance traveled by the accelerator pedal is exceeded.

A lock-up clutch of a hydrodynamic torque converter remains disengaged during shifts of a downstream transmission, when the drive motor is operated in the partial load range, and remains engaged during shifts of the downstream transmission, when drive motor is operated in a full load range.

Method for controlling a lock-up clutch of a hydrodynamic torque converter

A method of operating the torque converter lock-up clutch in a power transmission of a working machine comprising at least one hydraulically actuated lifting device. The torque converter lock-up clutch is actuated for disengagement when a predefined limit value for the position of the lifting hydraulic mechanism of the at least one lifting device is exceeded. When the position of the lifting hydraulic mechanism falls below a predefined limit value and when the turbine rotational speed exceeds a predefined threshold value, the torque converter lock-up clutch is reengaged.

Method for operating the torque converter lock-up clutch in a power transmission of a mobile machine comprising at least one hydraulically actuated lifting device

A method of actuating an interwheel differential lock of a mobile vehicle. The interwheel differential lock is actuated to engage depending on the speed of the vehicle, the accelerator pedal position and the gradient of the torque at the transmission output.

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Langenargen, Germany

Thomas Kurz