摘 要

总体方案设计包括：分析给定的技术参数及工作条件，进行调查研究、收集资料确定各个部分的结构形式、主要尺寸及估重，并做布置位置草图；

驱动系统设计包括：

⑴驱动系统传动方案的确定。采用单电机集中式电驱动系统，由减速箱总成、差速器总成及驱动桥组成，驱动电机与减速器主动齿轮直接相连，通过两级减速及差速器，将扭矩传送到左右两个驱动轮。电机轴线与车轮轴线平行，因此减速器采用两极圆柱齿轮传动。半轴采用全浮式结构，与轮毂用螺钉连接传递转矩。桥壳采用整体式结构，一端由轮毂轴承支承在车轮上，另一端与减速器相连^[1]。

⑵减速器的设计。分配传动比，计算动力和运动参数；按轮齿弯曲疲劳强度进行设计，计算齿轮的主要参数；按扭转强度设计轴的尺寸，按弯扭合成校核轴的强度；减速器箱体的设计；轴承的寿命校核。

⑶差速器、半轴、桥壳等零件的结构设计与强度校核。

关键词：驱动系统；减速器；驱动桥壳；差速器

abstract

The overall scheme design includes: analyzing the given technical parameters and working conditions, conducting investigation and research, collecting data to determine the structural form, main dimensions and weight of each part, and making layout sketches;
The drive system design includes:
(1) Determination of the drive system transmission scheme. The single-motor centralized electric drive system consists of a reduction gearbox assembly, a differential assembly and a drive axle. The drive motor is directly connected to the drive gear of the reducer, and the torque is transmitted to the left and right through two-stage deceleration and differential. Drive wheels. The motor axis is parallel to the wheel axis, so the reducer is driven by a two-pole cylindrical gear. The half shaft adopts a full floating structure, and the hub is screwed to transmit torque. The axle housing has a monolithic structure, one end is supported by the wheel bearing on the wheel and the other end is connected to the reducer ^[1].
(2) Design of the reducer. Distribute the transmission ratio, calculate the power and motion parameters; design according to the bending fatigue strength of the gear teeth, calculate the main parameters of the gear; design the shaft size according to the torsional strength, and synthesize the strength of the shaft according to the bending and torsion; the design of the reducer box; Bearing life check.
(3) Structural design and strength check of parts such as half shaft and axle housing.

Key words: drive system; reducer; drive axle housing; differential

Catalog

Chapter 1 Introduction 1

1.1 Introduction 1

1.2 Development trend of new energy vehicles 1

1.3 The composition of the electric vehicle drive system 2

Chapter II Overall Design of Electric Vehicle 4

2.1 Technical parameters 4

2.2 Construction form and working conditions 4

2.3 Main parameters of the car 4

2.3.1 Main dimensions of the body 4

2.3.2 Motor parameters 5

2.3.2.1 Motor power 5

2.3.2.2 Motor speed 6

2.3.2.3 Motor torque 7

2.3.2.4 Motor parameters 7

Chapter III Structural Design of Electric Drive System 8

3.1 Drive system overall design 8

3.2 Reducer design 8

3.2.1 Transmission ratio allocation 9

3.2.1.1 Transmission speed ratio upper limit: 9

3.2.1.2 The lower speed ratio of the transmission: 10

3.1.2.3Transmission ratio 10

3.2.2 Calculation of motion and dynamic parameters 11

3.2.3 Gear parameter calculation 11

3.2.3.1 High-speed gear calculation. 11

3.2.3.2 Low speed gear calculation 14

3.2.4 Design of high speed shaft 16

3.2.4.1 High speed shaft design 16

3.2.4.2 Check of high speed shaft 17

3.2.5 Intermediate shaft design 22

3.2.5.1 Intermediate shaft design 22

3.2.5.2 Intermediate axis check 23

3.2.6 Reducer box design 27

3.3 Differential design 28

3.3.1 Differential structure selection 28

3.3.2 Differential design calculation 29

3.3.3 Differential gear strength calculation 31

3.3.4 Differential bearing selection 32

3.4 Half shaft design 33

3.4.1 Determination of the shaft diameter of the half shaft 33

3.4.2 Spline design 34

3.4.3 Half shaft connection screw design calculation 34

3.5 Drive axle housing design 35

3.5.1 Drive axle shell structure scheme 35

3.5.2 Calculation of drive axle strength 35

Conclusion 39

Refrence 40

Acknowledgement 41

Chapter 1 Introduction

1.1 Introduction

Oil shortage, environmental pollution and climate warming are common challenges facing the global auto industry. Governments and industries have put forward their own development strategies and actively responded to maintain the sustainable development of their auto industry and improve future international competition. force. New energy vehicles have become a hot spot in the development of the automotive industry in the 21st century.

The automobile industry is an important pillar industry of the national economy and plays an important role in the national economy and social development. The new energy automobile industry is a strategic emerging industry. The development of energy-saving vehicles is an effective measure to promote energy conservation and emission reduction. At present, energy and environmental problems are becoming more and more serious, and public opinion pressure is unprecedented. Vigorously developing energy-saving and new-energy vehicles is an effective way to solve energy and environmental problems, and is also a powerful measure to realize national ecological civilization construction.

Pure electric vehicles can achieve zero pollution during operation and do not emit harmful gases that pollute the atmosphere. Even if the electricity consumption is converted into power plant emissions, the pollution is less than that of traditional cars, because the energy conversion rate of power plants is higher, and centralized emissions can more easily install to reduce pollution control equipment.

The noise and vibration levels of the motor during operation are much smaller than those of conventional internal combustion engines. At idle and low speeds, the comfort of an electric car is much higher than that of a conventional car. As the speed increases, the tire noise and wind noise become the main source of noise, and the two return to the same level. This feature of electric vehicles will undoubtedly help to improve the NVH performance of the car.

1.2 Development trend of new energy vehicles

(1) Breaking through battery technology is the key. As a power source, there is no battery that can be compared with oil. Power batteries have become a bottleneck restricting the development of electric vehicles ^[2].

(2) Diversified development of drive motors. The United States tends to use AC induction motors. In Japan, permanent magnet brushless DC motors are used. Germany and the United Kingdom have developed switch reluctance motors.