Zf Friedrichshafen Ag

Simon Geiger

Matthias Madlener

Matthias Duller

Sven Bieber

Stephan Schinacher

Robin Cramer

The invention relates to a method for accelerating a vehicle with a continuously variable transmission () where a gear ratio of the transmission is at first larger than a gear ratio of a virtual fixed gear. While the vehicle is accelerating, the gear ratio of the transmission is increased to the gear ratio of the virtual fixed gear. The transmission is then operated with the gear ratio of the virtual fixed gear.

Acceleration with virtual gear ratios from low speeds

A method of controlling a drive device of a construction machine with a split transmission, which is at least coupled, at an input side, to a drive force source and, on the output side, with a drive range change transmission so as to set at least two shiftable drive ranges. The method includes a detection step (S) for detecting drive dynamic requests for operation of the construction machine and a determination step (S) for determining whether a drive dynamic request with an increased drive dynamic is present. If a drive dynamic request with increased drive dynamics is determined, then a shifting step (S) is executed for shifting the drive range change transmission from a second, of the at least two drive ranges, to a first of the at least two drive ranges, to achieve increased driving dynamics of the construction machine.

Method for controlling a drive device of a construction machine

A power-split transmission which is designed to be operated with either first or second deceleration logics. The second deceleration logic has a higher deceleration dynamic than the first deceleration logic, and is designed to disengage an engaged range clutch immediately so as to reduce the transmission ratio by way of a hydrostatic unit with a maximum dynamic. A method of operating the transmission includes: monitoring various vehicle parameters while the vehicle is operated with the first deceleration logic; detecting that at least one set limit value has been exceeded while the vehicle operated with the first deceleration logic; activating the second deceleration logic, to immediately disengage an engaged range clutch; reducing a transmission ratio to a maximum using the hydrostatic unit, the hydrostatic unit being displaced with a maximum dynamic; and engaging the range clutch and activating the first deceleration logic.

Power split transmission and method for operating such power split transmission

A reversing method for reversing a travel direction of a working machine with a power-split transmission in which control signals are emitted by a control unit such that a reversing clutch, for the current travel direction, is disengaged and a reversing clutch for the new travel direction is engaged. The reversing clutches are controlled by control variables. If there is a difference between a reference control magnitude and a target control variable, the control variable is adapted. An adapted control signal is emitted, with which the reversing clutches are actuated, and for determining the target control variables for the disengaging and engaging of the reversing clutches, in addition to a translational factor and a rotational factor a load-dependent factor is determined and processed.

Method for reversing a direction of travel of a working machine comprising a power split transmission

During a shift from a first driving range to a second driving range in a continuously variable power-split transmission having a continuously variable branch and a mechanical branch, in which during the range shift, the synchronous rotation speed is kept constant, the range shift is discontinued if a predefined threshold of at least one driving requirement is exceeded.

Method for operating a power split transmission

A power-split transmission device for a vehicle, which connects a drive engine to a drive output, having a hydrostatic unit for continuous adjustment of the transmission ratio at a transmission unit, and two range clutches that alternately operate for respectively associated driving ranges with different transmission ratios. A control unit, during regular vehicle deceleration, implements the driving range change from a first range, with higher transmission ratios, to a second range, with lower transmission ratios, by switching from the first to the second range clutch in accordance with a synchronous point dependent deceleration control logic. In the special case of an unexpected increase of the deceleration dynamic at the beginning of an already initiated driving range change from the first to the second driving range, the control unit immediately forces the change by bypassing the synchronous point dependent deceleration control logic when other boundary conditions are fulfilled.

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Oberteuringen, Germany

Simon Geiger