VEHICLE TRANSMISSIONS AND VEHICLES INCORPORATING TRANSMISSIONS

摘要

The vehicle engine drives a gearbox (90) which drives road wheel via half-shafts (66) and axle (final reduction) gears (68). In order to reduce manufacturing costs without introducing excessive wear, the gearboxes of a range of vehicles (covering say a 2:1 power range) are alike. The increased power up the range is transmitted by driving the gearbox faster via an equalizing gear (16) which may be separate or an input stage of the gearbox (90) itself. The torques at the output (12) of the equalizing gears are the same throughout the range. The axle gears (68) have different ratios gA such as to establish the correct wheel speed nW throughout the range, taking into account also different wheel diameters. The axle gears (68) are two stage planetary units capable of high reductions needed at the top of the power range. The gears (68) preferably have two stages with rotationally fast planet wheels in a common carrier which also forms the wheel hub. The first stage has only an input wheel (sun wheel) while the second stage has only a fixed wheel which may be a sun wheel (lower power vehicle) or an annulus (higher power vehicle).