Wuhan University of Technology graduation design (thesis)

Design of drive axle for unmanned pure electric logistics vehicle

College (Department): School of International Education

Professional class: Automobile Engineering gj1503

Student Name: Ke Jun

Supervisor: Yu Houyu

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Abstract

With the increasing awareness of energy crisis and environmental protection, people pay more attention to pure electric vehicles. Some potential traditional automobile manufacturers at home and abroad often position their products in a high level, so it is difficult to popularize them among majority consumers. As a supplement to middle and high level pure electric vehicles, small and micro pure electric vehicles will reveal a great development potential. This kind of pure electric vehicle has the advantages of compact structure, light weight and low cost.

In this paper, the driving axle of an unmanned electric logistics vehicle based on XinShiQi Company is designed with the help of three-dimensional modeling software CATIA, and finite element analysis software ANSYS. In the design, the characteristics of the drive axle are explained firstly. According to the given data, the structure types and parameters of the final drive, differential, half shaft and universal joint are determined, and the strength is checked. Through calculating the size and referring to the similar parts of the existing vehicle, carry out the 3D model. Then import the model into finite element analysis software to obtain stress nephogram. The results are of great significance to the design and development of the driving axle of the electric logistics vehicle.

Key words: drive axle; electric logistics vehicle; final drive; differential

Contents

Chapter 1 Introduction 1

1.1 The purpose and significance of the research 1

1.2 Overview of research status in China and abroad 2

Chapter 2 Drive axle design 4

2.1 Drive axle type selection 5

2.2 Final drive design 6

2.2.1 Final drive structure technical solution 6

2.2.2 Final drive gear design 8

2.2.3 Strength check of shaft and key 15

2.3 Differential design 20

2.3.1 Main parameters selection of differential gear 20

2.3.2 The material of the differential gear 23

2.3.3 Differential gear geometry calculation 24

2.3.4 Differential gear strength calculation 25

2.4 Half shaft design 26

2.5 Universal joint design 28

2.5.1 Universal joint selection 28

2.5.2 Universal joint size selection 29

Chapter 3 CATIA 3D modeling 31

3.1 Software Introduction 31

3.2 Final drive modeling 31

3.3 Differential Modeling 32

3.4 Drive half shaft modeling 33

3.5 Axle case modeling 34

3.6 Drive axle overall 3D model 34

Chapter 4 ANSYS finite element analysis 36

4.1 Material Settings 36

4.2 Contact and grid settings 36

4.3 Constraints And Loading Settings 37

4.4 Analysis and comparison of results 37

4.5 Summary 39

Chapter 5 Conclusion 40

References 41

Acknowledgement 43

Appendix 44

Chapter 1 Introduction

1.1 The purpose and significance of the research

The design and manufacturing process of the drive axle are constantly improving and perfecting in a wake of the rapid development of the entire automotive industry. The development of parts and related industries has also promote the progress of the automobile industry. The automobile drive axle, which is one of the key components of automobiles, has also been developed accordingly. Each manufacturer has basically formed a situation of specialization serialization and batching in the process of research, development and production^[1].

China's research and manufacture of traditional vehicles are relatively backward in the world. It is almost impossible to catch up with those big automobile manufacturing countries in a short period of time. However, in the study of pure electric vehicles, our progress is not too late. Our experience and research and development capabilities allow us to stay ahead of the world. In addition, petroleum, as a non-renewable energy source, if we can promote and use pure electric vehicles, it will be of great help to solve energy problems. For pure electric logistics vehicles, market requirement has always existed, and as more and more cities impose restrictions on fuel vehicles, the market faced a huge potential^[2].

In addition, the drive axle is the end part of the automobile transmission system. It is generally composed of final drive, differential, half shaft, axle case and other components. It has the following functions: deceleration and torque increase through the final drive; The direction of torque transfer is changed by the bevel gear pair or the hypoid gear pair of the final drive; The inner and outer wheels are turned at different speeds by the differential, and the load-carrying and force-transmitting effects are realized by the axle shell and the wheel. The structural and parameters of drive axle have a great influence on the reliability and durability of the vehicles, and also have great effects on the performance of the car such as dynamic, economy, ride comfort, passing ability, maneuverability and steering stability. The detection of these properties can be detected by virtual prototype technology^[3]. Therefore, research on the design method of the drive axle is relatively important^[4].