Search Results

Tapered roller bearings have proven successful in a number of high-volume automatic transaxle designs. Typically, tapered roller bearings are required to carry high loads generated by helical and hypoid gears. To meet the demands of a successful design, a number of factors must be considered in the selection and application of tapered roller bearings. This paper presents a discussion of these factors as well as results from Chrysler's transaxle testing. Selection of tapered roller bearings is based on the transmission duty cycle developed using load and speed histograms, gear data, size constraints, and life requirements. A bearing life analysis considering the total transaxle system is conducted using a sophisticated computer program. Various system effects are analyzed including the load/speed cycle, housing and shaft rigidity, lubrication, bearing setting, thermal effects, and bearing internal design.

A new electronically controlled transaxle has been put into production for Chrysler's family of LH cars. Among the attributes of this new transaxle are its ability to handle engines of high torque and high power coupled with high-speed shifts. Engine torque management is used in specific operating regimes. A feature of the transaxle is electronic modulation of the converter clutch. A number of logic features have been combined with hardware to provide good performance and shift quality over a wide operating range. An output transfer chain and a hypoid gear set are used to provide torque to the front wheels in a longitudinal power train orientation. Obtaining acceptable endurance life of the hypoid gears within an aluminum housing presented a significant challenge. New approaches were required to provide a chain-sprocket system with acceptable noise characteristics.