Joseph E Muhleisen

US Patent:

20030141479, Jul 31, 2003

Filed:

Jan 31, 2002

Appl. No.:

10/062028

Inventors:

Donald Witzel - Pittsford NY, US
Joseph Muhleisen - Livonia NY, US

International Classification:

F16K001/22

US Classification:

251/305000

Abstract:

An improved planetary traction drive mechanism for use in actuating a throttle valve assembly. An electric drive motor supports a cup-shaped member defining the outer ring of the mechanism. The drive shaft of the motor extends into the cup-shaped member to define a sun roller and forming an annular space between the sun roller and the outer ring. An output plate is rotatably supported on the drive shaft, and one or more planetary friction rollers disposed in radial compression between the outer ring and the sun roller are mounted on the plate. An output shaft extends from the plate and may or may not be coaxially aligned with the sun roller. The output shaft may be connected via a link to a lever arm on the throttle shaft of the throttle valve, which may be used on an internal combustion engine. The planetary rollers are formed from a resilient composite polymer which is mildly compressible, has a suitably high coefficient of sliding friction against metal, a low coefficient of wear, and a high resistance to flexural fatigue. The rollers may be formed as solid disks of resilient polymer but preferably include deformable cylinders of resilient polymer loosely positioned on the pins. The rollers have unstressed diameters greater than the radial distance between the sun roller and the outer ring, so that the rollers must be compressed in order to be installed therein, thereby creating tractive friction with the sun roller and the outer ring.