Vehicle gearbox for drive train of vehicle, comprises three forward gears, where progression in between transmission ratios of two adjacent forward gears decreases with increasing pitch around grade difference

摘要

The vehicle gearbox comprises three forward gears, where the transmission ratios of the forward gears are determined, such that the progression in between the transmission ratios of the two adjacent forward gears decreases with increasing pitch around a grade difference. The differentiation between the transmission ratio of the former forward gear and the transmission ratio of the higher forward gear is given a polynomial in the grade difference, whose degree is determined by the number of forward gears. Independent claims are also included for the following: (1) a drive train with an engine and a vehicle gearbox; (2) a method for determination of ratios of forward gears in a stepped transmission; and (3) a method for dimensioning of gear wheels of forward gears.