Graduation project of Wuhan University of Technology（Thesis）

The design of drive axle of 1070 pure electric truck

College：Internationl Education College

Professionamp;class：Automotive gj1401

Name： Wujun

Mentor： Han aiguo

Dissertation Originality Statement

I solemnly declare that the submitted paper is the independent study conducted by the Institute under the guidance of my mentor. Except for the content specifically quoted and cited in the text, this paper does not include any results that have been published or written by any other individual or group. I fully realize that the legal consequences of this statement are my own responsibility.

Author Signature：吴俊

June ，6^th ，2018

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Author Signature吴俊

June ，6^th ，2018

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Abstract

The automobile axle is an important assembly of the automobile. Its structural type and design parameters not only have an important influence on the reliability and durability of the automobile, but also on the driving performance of the automobile such as dynamic performance, economy, smoothness, and passability. There is a direct impact on maneuverability and handling stability. Therefore, the structural type selection, design parameter selection and design calculation of the axle are important for the vehicle's complete vehicle design. This text mainly carries on the overall design to EQ1070TTBEV, introduces the structure principle of the drive axle, the choice of layout type and the design, calculation and drawing process of the main reducer, half shaft and axle housing, and chooses the spiral bevel gear main according to the characteristics of the EQ1070TTBEV truck. Reducer, rationally arrange all gear parts, design and calculate parameters of each gear, half shaft, etc., and check each part.

Key Words：EQ1070 truck；design；drive axle；pure electric vehicle

Contents

Chapter 1 Parameter calculation of vehicle 1

1.1 Number of axle, driving form, layout form 1

1.2 Design of main parameter 2

1.2.1 Main parameter 2

1.2.2 Distribution of axle load 2

1.3 The power, rotate speed and torque of electric motor 3

1.3.1 Maximum power P_max and corresponding rotate speed n_e 3

1.3.2 Maximum torque T_emax and corresponding rotate speed n_T 3

1.4 Choice of tyre 4

1.5 conforming the transmission ratio of main reducer 4

1.6 Conforming the maximum ratio of drive system and calculating the maximum ratio of gearbox 5

Chapter 2 Total design of drive axle 5

2.1 Structure type of drive axle 5

2.2 Gear type of main reducer 7

2.3 Deceleration form of the main reducer 8

2.4 Basic selection and calculation of parameters of reducer 9

2.4.1 Number of Main and driven bevel gear teeth—z₁ and z₂ 9

2.4.2 Selecting and calculating parameters of bevel gears 9

2.5 Calculation of bevel gear strength of main Reducer 12

2.5.1 Peripheral force on unit tooth length 12

2.5.2 The bending strength of gear teeth 12

2.5.3 Teeth tooth surface contact strength 14

2.6 Design of main reducer bearing 15

2.6.1 Force on bevel gear teeth 15

2.6.2 Bearing load of bevel gear 17

2.6.3 Determination of bevel gear bearing model 18

2.7 Design of differential 19

2.7.1 Selection of differential 19

2.7.2 Design of ordinary bevel gear differential gear design 20

2.7.3 Calculation of ordinary bevel gear differential gear strength 23

2.8 Design of drive wheel drive 24

2.8.1 Type of axle 24

2.8.2 Design and calculation of axle 25

2.8.3 Design calculation of Full-floating axle shaft 26

2.9 Design of drive axle housing 27

2.9.1 Structure type bridge shell 28

2.9.2 Analysis and strength calculation of axle shell force 28

Chapter 3 Conclusion 30

Reference 31

Acknowledgement 32

Appendix 33

Chapter 1 Parameter calculation of vehicle

• 1. Number of axle, driving form, layout form

The maximum total mass of EQ1070TTBEV is 7100kg, and the total mass is less than 19t. It adopts a two-shaft scheme with simple structure and low manufacturing cost. The driving mode adopts a 4×2 drive mode with simple structure and low manufacturing cost, and the rear axle has four wheels.

The layout of trucks can be divided into four types: flat head type, short head type, long head type and offset type, depending on the relative positions of the cab and the motor.

The flat head type features a cab above the engine, a high utilization of the area of the vehicle, a good field of vision, a small minimum turning radius, and good maneuverability; however, the front axle has a large load and thus the vehicle's passing performance deteriorates; the cab has a turnover mechanism and Locking mechanism, complex mechanism; entering and exiting the cab is not as convenient as the long head type truck; the heating and vibration in the cab are relatively large; when the frontal collision occurs, especially the miniature, light flat-head truck, the driver and the front row occupant are seriously injured. The possibility of increase.