Graduation Design of Wuhan University of Technology

Design of Motor-drive Bridge Integrated Drive System for Low Speed Electric Logistics Vehicle

College： International Institute Of Education

Major and Class： Automotive Engineering Class 4

Student： Li Gongbo

Supervisor： Deng Jiadong

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Abstract

With the increasing of energy problems and environmental pollution problems,the gradual replacement of traditional fuel vehicles by new energy vehicles has become an inevitable trend in the development of automobile industry.This shift takes place not only in passenger cars,but also in commercial vehicles that require higher endurance and carrying capacity.The main purpose of this paper is to provide a design scheme for the power system of low speed electric logistics vehicle which is very popular nowadays.

In the aspect of automobile electric drive,there are many more mature driving system arrangement schemes.By comparing the advantages and disadvantages of many different schemes,this paper finally determines that the wheel hub motor of planetary gear reducer reducer is the most suitable driving scheme for the design goal,and designs and calculates it,the main contents of which are as follows：

1. In view of the advantages and disadvantages of the current popular driving arrangement scheme,the most suitable layout scheme for low speed electric logistics vehicle is selected,that is,the hub motor driving mode is adopted.At the same time,according to the main parameters and dynamic requirements of the vehicle,select the appropriate motor model.
2. According to the requirements of the target,the NGW planetary gear reducer is chosen as the main deceleration mechanism,the central wheel is driven by motor,and then the planetary wheel is driven.Finally,the vehicle is driven directly by the rotating arm connected with the planetary wheel to connect the output of the hub,and the parameters of the gear structure are calculated and checked.
3. The main parts of the transmission system,such as center wheel,planetary wheel,gear ring and other parts,are designed and catia 3D modeling.At the same time,the force analysis of the center the largest load is carried out to confirm that its structure meets the strength requirements,and finally the virtual assembly is carried out with the catia.

Key Words ：Low-speed electric;logistics vehicle;power system;structure design;parameter calculation

Content

Introduction 1

Abstract 3

Content 4

Chapter 1 Introduction 6

1.1 Background 6

1.2 Status of research 7

1.2.1 Foreign Studies 7

1.2.2 Domestic development and current situation 8

1.3 Main design contents and significance of the project 9

1.3.1 main design content 9

1.3.2 technical programmes and measures 9

Chapter 2 Selection of Transmission Structure and Parameter Design of Power System 10

2.1 Selection and Design of Transmission Structure 10

2.1.1Comparison of Transmission Structure Scheme 10

2.1.2 Final programme determination 13

2.2 Power system parameter matching and selection 13

2.2.1 vehicle performance requirement analysis 13

2.2.2 Calculation of Drive Motor Parameters 14

2.2.3 Determination of Motor Torque and Speed 15

Chapter 3 Structure Design and Parameter Calculation of Main Reducer 17

3.1 Structure selection of main reducer 17

3.2 Gear parameter design of main reducer 17

3.2.1 Gear Condition Requirements 17

3.2.2 Gear Parameter Design 18

3.2.3 meshing parameter calculation 19

3.2.4 Gear Strength Check 21

3.3 Design calculations for other components 25

3.3.1 input shaft design 25

3.3.2 planetary axis design 26

Chapter 4 3D Virtual Design of Transmission System 30

4.1 Structural design of transmission key parts 30

4.1.1 Central Wheel Structure Design 30

4.1.2 Design of planetary wheel 30

4.1.3 Design of ring structure 31

4.1.4Design of swivel arm 31

4.2 Motion Simulation of Transmission Parts 32

4.3 3D Simulated Assembly of Transmission System 33

Summary and Prospect 35

References 37