The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 18, 2013
Filed:
Dec. 03, 2010
Tobias Zollner, Lindau, DE;
Bernd Allgaier, Kressbronn, DE;
Christian Schwemer, Sigmarszell, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
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.