CONTINUOSLY VARIABLE DUAL MODE TRANSMISSION

摘要

A dual mode continuously variable transmission for use with motor vehicles includes a transmission input shaft, a transmission output shaft, and a variator disposed between the transmission input shaft and the transmission output shaft. A mixer gear set is operably disposed between the transmission input shaft and the variator output shaft. A clutching element is operably disposed between the input shaft the mixer gear set. The variator is configured to continuously vary a ratio of input torque to output torque between the variator shafts responsive to commands from an electronic control unit. The variator input shaft is drivingly connected to the input shaft and the variator output shaft is drivingly connected to the output shaft. The clutching element selectively connects and disconnects the input shaft and the mixer gear set to operate the transmission in a power splitting mode of operation and a variator only mode of operation. An electronic control unit incorporates logic rules by which the clutching element maintains the transmission in a variator-only mode of operation in a first vehicle speed range, and maintains the transmission in a power splitting mode of operation in a second vehicle speed range greater than the first vehicle speed range.