Variable speed transmission

US6186917A · kind A · utility

Assignee

• LuK Getriebe-Systeme GmbH · DE

Inventors

• Oswald Friedmann · Lichtenau, DE
• Bernhard Walter · Oberkirch, DE

Key dates

• Filing date: Nov 24, 1998
• Grant date: Feb 13, 2001
• Expiry date: Nov 24, 2018

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H61/662
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A continuously variable speed transmission with two adjustable sheaves and an endless chain trained over the sheaves has a torque transmitting and monitoring unit which is installed between a prime mover, such as the engine of a motor vehicle, and an axially movable flange of one of the sheaves. The monitoring unit has two annular plenum chambers which are sealed from each other while the ratio of the transmission is within a first range, and which communicate with each other when the ratio is within a second range. A check valve between the two chambers can employ a resilient annular seal having a U-shaped cross-sectional outline. A radially outer annular portion of the seal has a lip which normally bears against the internal surface of an annular member of the valve. The seal further comprises an annular radially inner portion, and the radially inner and/or outer portion of the seal can be provided with L-shaped, polygonal and/or otherwise configurated and/or profiled reliefs to further ensure proper operation of the valve.