Analytical and Numerical Calculations of the Gearshift Process Dynamics of Electric Vehicle Power Unit with a Shaft Gearbox

Abstract

The article is devoted to the study of dynamic processes in the power unit of electric vehicle when shifting gears in a two-shaft gearbox by means of a cone synchronizer. A two-mass dynamic model is used to obtain analytical dependences. This model of the power unit makes it possible to obtain a qualitative idea and a quantitative assessment of the electric vehicle gearshift process, to select parameters of the laws of engine torque and synchronizer friction moment change. For a more precise description of vibrations in a power unit, taking into account its elastic properties, a three-mass dynamic model is considered. An example of calculating the time of shifting from low gear to top one for the MAZ-4381EE delivery electric truck is given. The studies conducted have shown that the vibrational processes occurring in the power unit of electric vehicle do not significantly affect the dynamic loading of its elements.

Keywords

• electric vehicle
• power unit
• shaft gearbox
• dynamic model
• cone synchronizer
• electric motor mechanical characteristic
• gearshift time
• gearshift algorithm