Transmission apparatus and method

摘要

A transmission has a torque converter with an impeller, primary and secondary turbines and a stator. In a first planetary gear set the carrier is connected to the primary turbine, the sun gear is connected to the secondary turbine and the ring gear is connected to a one-way clutch. A second planetary gear set has a second carrier connected to the output shaft and a second ring gear connected to the first carrier. A brake is connected to the one-way clutch and to the second sun gear for low forward operation. The one-way clutch is used in the first phase of low forward and in reverse. A clutch locks up the second planetary gear set in drive operation. The one-way clutch is centrifically disabled before and during drive operation. A second brake brakes the primary turbine, the first carrier, and the second ring gear in reverse operation, causing the secondary turbine to drive the first sun gear and the first ring gear to drive the second sun gear through the one-way clutch to turn the output shaft slowly in reverse. A second one-way clutch connected to the stator provides phase differentiation in low forward and drive operations.