Thermal compensating bearing support structure for transmission case

Abstract

Abstract An improved structure supports a bearing in a bore provided in a portion of a transmission case and prevents relative rotation therebetween. In a preferred embodiment, the clutch housing portion of a transmission case is made from aluminum and includes an interior wall having a bore formed therein. A circumferential groove is formed in the side wall of the bore, and a compressible or elastomeric O-ring is disposed in the groove. A bearing is made from steel and includes an inner race, an outer race, and a plurality of rollers disposed between the races. As the bearing is pressed into the bore, the O-ring is compressed completely within the groove. So long as both the aluminum clutch housing and the steel outer race of the bearing remain in a relatively cold condition, the outer race will frictionally engage the inner surface of the bore, thus preventing any relative rotational movement therebetween. However, after operation of the transmission, the temperatures of both the aluminum clutch housing and the steel outer race of the bearing will increase. Because aluminum expands at a greater rate per unit temperature than steel, the inner diameter defined by the bore will increase at a greater rate than the outer diameter defined by the outer race. As a result, a small gap may be created therebetween. When this gap is created, the O-ring expands out of the groove formed in the inner surface of the bore to maintain a frictional engagement with the outer race of the bearing. Consequently, relative rotation between the two is prevented. This avoids premature wear and failure which can result from such relative rotational movement.

Inventors

• 👤 George F. Schetter
• 👤 Steven N. Tucker, Jr.

Bibliographic Details