VIHICLE TRANSMISSION SYSTEM

摘要

A transmission system for a vehicle includes an input shaft 2 connected to a differential mechanism 4, 6, 8, 10, which has two output shafts 12, 20. The two output shafts carry first and second coaxially mounted sunwheels S1, S2, respectively of an epicyclic gear system which mesh with first and second sets of planet wheels P1, P2, respectively. The gear ratio of the first sunwheel with the first set of planet wheels and the second sunwheel with the second set of planet wheels are different. Each first planet wheel is connected to a respective second planet wheel to rotate therewith about a respective common planet shaft 22. The planet shafts 22 are connected to a common carrier 24 which is rotatably mounted coaxially with the first and second sunwheels. A single selectively operable speed changing means 26, 28 is provided which is connected to the carrier 24 and is arranged to increase or decrease the speed of rotation of the carrier about its axis. The transmission system also includes at least one sensor 38 arranged to produce a single indicative of an operating parameter of the vehicle or its engine and a controller 36 connected to the sensor 38 and to the speed changing device 26, 28 and arranged to operate the speed changing device in response to the signal.