Methods for Calculating the Load of Electric Vehicle Gearboxes Using their Dynamic Models

Abstract

A two-mass dynamic model of an electric vehicle is considered to obtain analytical dependences describing the gearshift process in a shaft-planetary gearbox. The calculations are based on the optimal diagram of shifting gears from low to high without interruption of the power flow from the electric motor. At the stage of gear shifting, at which the kinematic gear ratio of the gearbox changes from u1 to u2, Lagrange equations of the second kind are used to determine the time dependences of angular velocities of the input and output shafts of gearbox. An example is given for calculating the gearshift time from low gear to high one for the MAZ-4381EE delivery electric truck, as well as a refined calculation for a multi-mass dynamic scheme is carried out.

Keywords

• electric truck
• gearbox
• electric motor
• diagram of shifting gears
• power circulation
• dynamic model
• friction clutch
• lagrange equations of the second kind
• slipping time