New Energy City Bus Integral Power Train Development

Auto industry of China has entered a new era of new energy,especially in the field of commercial bus has fully switched from traditional internal combustion engine as the power supply to the motor for driving the vehicle.The purl electric power train technology has entered the mature period gradually in nearly five years through market pull.Considering the actual working condition,the drive system is mainly divided into two types.The motor direct drive and motor plus gearbox drive.Their power output are based on the characteristic curve of the traditional diesel engine driven system,is characterized by low rotation speed and high torque.It can by quickly transform into a product through this inheritance design and can also meet the operation needs of the vehicle,so as to obtain a better driving experience which is easier to be accepted by the market.This topic's mainly thinking is how to transfer the design concept of passenger car drive system into purl electric bus through the research of the whole vehicle industry drive system technology.We can gain higher driving efficiency and better performance price rate by this solution.We use high rotation speed permanent magnet synchronous motor plus reduction gear's solution of purl electric passenger car to replace directly drive system by low rotation speed motor.At the same time we integrated the drive motor and planetary gear reducer to save the installation space and make it lighter.It can be much better solution for the purl electric bus than currently power train.Mainly project implementation process is as below:Firstly,we confirmed the product segment and made the general solution design.Accor ding to the development of the local domestic bus market situation,the electric city bus of 8~10 meters in length has the maximum demand.So we selected this product as the prototype to verification the new drive system.Base on that the detailed performance calculation and analysis of the product are carried out and finally we determined this drive system's technical parameters and layout.A prototype is made in Yangzhou accordingly.Secondly,the integrated drive system is developed including high speed permanent magnet synchronous motor planetary gear reducer\drive system controller\integrated structural design and lightweight design.Finally,several rounds of detailed road comparison tests were carried out.This paper fully verifies the design objective of the integrated drive system and the feasibility of replacing the traditional direct drive system.