Power transmission unit for motor vehicles.

摘要

A power transmission unit (100) for a motor vehicle comprises an auxiliary transmission (110) for selectively completing low and high speed drive power trains, the auxiliary transmission (110) having an input shaft (111) drivingly connected to an output shaft of an engine through a disengageable coupling (20), a primary transmission (30) arranged between the disengageable coupling (20) and the auxiliary transmission (110) and having a main sleeve shaft (131) in surrounding relationship to the input shaft (111) and a countershaft (32) arranged in parallel with the main sleeve shaft (131), the main sleeve shaft (131) being connected with an output member (113) of the auxiliary transmission (110) and integrally provided with a plurality of drive gears (31a - 31d) for selectively driving a respective change-speed gears (32a - 32d) on the countershaft (32), and a final drive gearing (70) drivingly connected to the countershaft (32) to drive a differential gear unit (80).