Zf Friedrichshafen Ag

Friedrichshafen Ag

Tobias Zollner

Bernd Allgaier

Holger Bacher

Patrick Peter

Anton Fritzer

Thomas Lemp

Christian Schwemer

Clemens Kuhn

Christoph Ommer

Alexander Pfau

Lorenz Fehrenbach

Stefan-Ulrich Prange

Stefan Gierer

Jakob Scholz

A method of controlling an auxiliary pump for supplying the hydraulic fluid of a hybrid transmission of a vehicle. The auxiliary pump, after the expiration of a predetermined time interval of deactivation, is activated to prevent accumulation of air in the intake area of the auxiliary pump. In addition, a device for the execution of the method, in which a control device is provided which has its signals connected with the electric auxiliary pump for the purpose of controlling the auxiliary pump in order to prevent accumulation of air in the intake area of the auxiliary pump.

Method and device for controlling an auxiliary pump for a transmission

A method of controlling a hybrid drive-train of a vehicle having a combustion engine with a driveshaft, a transmission with an input shaft and an output shaft that drives a transfer box. An electric machine has a rotor that is connected to the transmission input shaft. A separator clutch is arranged between the engine driveshaft and the transmission input shaft. For coupling of the engine, the engine is first accelerated, with a rotational speed regulation, toward a target speed until a reference speed is reached or exceeded while the clutch remains disengaged, then, with continuous speed regulation, the engine is adjusted to a corrected target speed while the clutch is engaged until a target torque is obtained, then, with torque control, the engine is adjusted to the target torque while the clutch, with differential rotational speed regulation, is regulated to a target speed difference, and finally the clutch is engaged.

Method for controlling a hybrid drive train of a motor vehicle

A method of operating a drive-train of a hybrid vehicle which comprises at least a hybrid drive with an internal combustion engine and an electric machine, an automatic or automated change-speed transmission connected between the hybrid drive and a drive output, and a clutch connected between the internal combustion engine and the electric machine. When starting the internal combustion engine from a purely electric driving mode, the clutch is initially disengaged. To start the internal combustion engine, the clutch is at least partially engaged and the internal combustion engine is drag-started by the electric machine, and, in parallel with starting the internal combustion engine, a downshift in the transmission is initiated once a rotational speed of the internal combustion engine reaches or exceeds an applicable threshold value.

Method and control unit for operating a drive train of a hybrid vehicle

A method of operating a vehicle hybrid drive-train in which, depending on the operating situation, the engine and electric machine either operate individually or together. The engine and the electric machine can be coupled or separated by a clutch. The engine can be started by the electric machine or a separate starting device. To co-ordinate transmission shifts and required engine starts, during a transmission shifting process, if the engine needs to be started, then based on whether the shift is an upshift, a downshift, a traction shift or an overdrive shift and also depending on the type of engine start required, it is first determined whether the shift should be completed, at least partially completed or discontinued before carrying out the start and, based on this determination, measures for continuing, at least partially continuing or discontinuing the shift process are initiated.

Method for operating a hybrid drive train of a vehicle

A method of operating a motor vehicle having a drive aggregate, a transmission and a hydraulic system. The transmission has shift elements and, for each gear, only a portion of the elements are engaged while a remainder are disengaged. The hydraulic system has main pump driven by the drive aggregate and an auxiliary pump. The method tests the functionality of the auxiliary pump. The drive aggregate and the main pump are insufficiently driven such that the shift elements can not engage. The auxiliary pump is driven to provide required pressure such that all but one of the shift elements fully engages. The remaining shift element is then first engaged up to its engagement point and then either engaged beyond its engagement point or another unengaged shift element is engaged beyond its engagement point. The functionality of the auxiliary pump is determined based on changes in the drive aggregate's rotational speed.

Method for operating a motor vehicle and a control device for said vehicle

A method for operating a hydraulic system of an automatic transmission, in particular in a hybrid drivetrain, in which the hydraulic system comprises a main pump that is powered by an internal combustion engine and/or an electric drive motor, an electric auxiliary pump and a system pressure valve for setting a system pressure, to ensure various operating functions. In addition to the main pump, the electric auxiliary pump also supplies the hydraulic system with a volume flow of an operating medium. The loading of the electric auxiliary pump is determined in an electronic control unit with regard to the value of the system pressure and the loading of the electric auxiliary pump is limited, by the electronic control unit, with regard to the selected operating function.

Growing community of inventors

Lindau, Germany

Tobias Zollner