Process for actuating a transmission mechanism

US8088040B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Peter Schiele · Kreßbronn, DE
• Klaus Steinhauser · Kreßbronn, DE

Key dates

• Filing date: May 6, 2008
• Grant date: Jan 3, 2012
• Expiry date: May 1, 2030

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2312/14
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A process for actuating a transmission mechanism having hydraulic shifting elements for changing gear ratios by using electric actuators to adjust the actuating pressures of the shifting elements. Upon a request from an engine start/stop function for shutdown of an engine, the flow of electrical current to the actuators is changed from an operating level to a standby level depending upon the operating pressure of the shifting elements. Upon the request for startup of the engine, the flow or electrical current is changed from the standby level to the operating level. A system pressure in the hydraulic system is zero when the engine is shutdown, and the power consumption in the transmission mechanism is lower at the standby level than the operating level.