Patent · US Active

Hydraulic system for an automatic transmission

US9726233B2 · kind B2 · utility

0Cited by

5References

16Claims

0Family size

Assignee

ZF FRIEDRICHSHAFEN AG · DE

Inventors

Christoph Margraf · Markdorf, DE
Stefan Brom · Friedrichshafen, DE

Key dates

Filing date	Dec 16, 2015
Grant date	Aug 8, 2017
Priority date	—
Expiry date	Dec 16, 2035

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF15B15/261
WIPO fieldMechanical elements
WIPO sectorMechanical engineering

Abstract

A hydraulic system for operating an automatic transmission for motor vehicles includes a hydraulic actuator for operating a clutch and a stop valve, whereas the actuator has a pressurizable actuating pressure chamber, which can be closed in a pressure-tight manner by means of the stop valve, such that the clutch pressure is maintained independent of the other pressures of the hydraulic system. The stop valve includes a closure device that is movable by means of a hydraulic control pressure (p_S) into a closed position, in which an actuating pressure chamber port, and thus the actuating pressure chamber, is closed by means of the closure device. The closure device is movable into an open position at least by means of the force of a spring, in which the actuating pressure chamber port is opened. Thereby, the stop valve features a shiftable locking device, by means of which the closure device can be fixed in the closed position.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.