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:
Oct. 06, 2020
Filed:
Feb. 17, 2017
Zf Friedrichshafen Ag, Friedrichshafen, DE;
Markus Herrmann, Scheidegg, DE;
Thilo Schmidt, Meckenbeuren, DE;
Armin Haugg, Friedrichshafen, DE;
Alexander Haberstock, Ravensburg, DE;
Christian Popp, Kressbronn, DE;
ZF FRIEDRICHSHAFEN AG, Friedrichshafen, DE;
Abstract
A hydraulic system for a transmission of a motor vehicle, the system having first and second pumps for conveying hydraulic fluid into primary and/or system-pressure circuits so that an intended pressure prevails in the circuits. The system further including liquid retention means preventing a flow of hydraulic fluid conveyed by the second pump from being conducted through the first pump when the first pump is not conveying and the second pump is conveying, and preventing a flow of hydraulic fluid conveyed by the first pump from being conducted through the second pump when the second pump is not conveying and the first pump is conveying. The system additionally including a sailing-mode lubricating valve for controlling, by an open-loop system, a flow rate of hydraulic fluid conveyed by the second pump into the primary and/or secondary system-pressure circuits such that the intended pressure is set in the system-pressure circuits.