Technical Paper
Thermal Compensating Tapered Roller Bearing for Enhancement of Transmission and Transaxle Performance
1991-02-01
910799
Automotive transmissions and transaxles use aluminum housings for weight reduction and tapered roller bearings for increased reliability. The initial bearing setting is obtained by using selective shims to account for tolerance variations of the transmission or transaxle components. Aluminum transmission and transaxle housings have a coefficient of thermal expansion approximately twice that of steel shafts and bearings. This difference results in a change to the initial bearing setting, as temperatures vary. For a direct bearing mounting arrangement (cup adjusted), the bearing setting becomes looser as the operating temperature increases, and tighter as the temperature decreases. Improved operating bearing setting is achieved through the use of a thermal compensating bearing.