Hydraulic control system for a clutch and transmission

US4515255A · kind A · utility

Assignee

• BorgWarner Inc. · US

Inventors

• William J. Haley · Ithaca, US
• Guenter Neumann · Bad Salzdetfurth, DE

Key dates

• Filing date: Aug 6, 1982
• Grant date: May 7, 1985
• Expiry date: Aug 6, 2002

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60W10/10
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A fluid control system for a continuously variable transmission utilizing a first valve which is manually operable, and a second valve operable by a fluid motor which fluid motor also provides engagement and disengagement of two gear ratios. The first valve directs fluid flow from a fluid source to the fluid motor and to the second valve for communication to a fluid actuated starting clutch. Fluid for the clutch and fluid motor are only provided when the first valve is selectively engaged to the first or second operable gear ratios thereby directing fluid from the fluid source to the fluid actuated motor. The fluid motor is operable to move a gear engaging means and simultaneously move the second valve to an aligned port position permitting fluid flow to the starting clutch. The clutch is only engaged when the manually operated valve is in the first or second gear ratio position, therefore, independent park and neutral positions have been obviated by the fact that such a starting clutch is no longer providing power to an output means. In an alternative embodiment a pressure modulator valve is interposed between the fluid source and the first valve to control the line pressure to th…