Graduation Design of Wuhan

University of Technology (Thesis)

Design of Double Wishbone Independent Suspension for Passenger Vehicle

College (Department)：School of International Education

Class： Class 1 grade 15 Auto gj

Student name： Weike Fu

Supervisor： Ying Yang

Originality Statement of Dissertation

I solemnly declare that the papers submitted are the results of my independent research under the guidance of my supervisor. In addition to the content cited in the paper, this paper does not include any other works published or written by individuals or groups. I am fully aware that the legal consequences of this statement are borne by me.

Author signature：

Date：

Authorization for Copyright Use of Dissertations

The author of this dissertation fully understands the regulations of the school concerning the guarantee and use of the dissertation. He agrees that the school shall retain and submit copies and electronic versions of the dissertation to the relevant dissertation management departments or institutions, allowing the dissertation to be consulted and borrowed. I authorize the provincial excellent bachelor's dissertation selection institutions to compile all or part of this dissertation into relevant data for retrieval, and can use photocopying, abbreviation or scanning to save and compile this dissertation.

This dissertation is1、Classified 囗,This Authorization shall apply in years

2、Unclassified 囗.

（Please type "√" in the corresponding box above）

Author signature： Date：

Supervisor signature： Date：

Abstract

Driving axle parts, structure is complex. Drive bridge as the four major automobile assembly, its performance has a direct impact on vehicle performance. This paper is mainly about the design of NISSAN 2.0T drive axle.

The basic function is to drive axle drive shaft or transmission to increase the torque and properly reduce speed assigned to the left and right drive wheels, drive axle is also under the second road and the frame or body between the vertical force, longitudinal force and lateral force, and the braking force and the reaction torque. Drive axle is composed of main reducer, differential, half shaft, universal joint, drive axle bridge shell. Drive axle is in the automobile power transmission assembly of. Driving axle design is reasonable or not directly related to automobile use performance is good or bad, drive axle is an important vehicle component. it suffered from a road surface and suspension of all forces and moments, is in the automobile the worst working conditions of one of the assembly, if designed properly it will cause serious consequences.

Based on the driving axle of traditional design method for the foundation, a detailed study of the NISSAN 2.0T car driving axle design method, put forward some feasible design ideas. According to this train of thought, design and calculate data and draw the steering driving axle parts diagram. At the same time, I also find the existing NISSAN 2.0T car driving axle structure principle, from the vehicles on the drive axle of the whole structure to deepen understanding, combined with the atest information about driving bridge and vehicle design book knowledge to design, sketch, and then using AUTOCAD software to provide the general assembly drawing, design work efficiency.

Key words: automobile driving axle main reducer differential half axle

Catalog

Chapter 1 Introduction 1

1.1overview 1

1.2 Theoretical Research Status of Drive Bridge Design and Analysis 2

1.3 When designing the driving axle, the following basic requirements should be met 2

Chapter 2 Driving Axle Structural Scheme 4

2.1 Structural Scheme Analysis 4

Chapter 3 Design of Main Reducer 5

3.1 Structure of Main Reducer 5

3.2 Types of Main Reducer 6

3.3 Supporting Forms of Main and Following Helical Cylindrical Gears of Main Reducer 7

3.4 Selection and calculation of basic parameters of main reducer 8

3.4.1Determination of Main Deceleration Ratio () 8

3.4.2 Determination of Calculating Load of Main Reducer Gear 9

3.5 Selection of Basic Gear Parameters of Main Reducer 13

3.5.1 Selection of Tooth Number of Main and Following Gears 14

3.5.2 Design and calculation of helical gears 14

3.5.3 Gear Parameter Table of Main Reducer 16

Chapter 4 Design of Differential 18

4.1 Differential Structure Selection 18

4.2 Gear Design of Common Bevel Gear Differential 19

4.2.1Selection of Basic Parameters of Differential Gear 19

4.2.2 Geometry calculation and strength calculation of differential gears 20

4.2.3 Parameter table of car planetary gears and half shaft gears 23

Chapter 5 Transmission Design of Drive Wheels 25

5.1 Half shaft type 25

5.2 Half-axis design calculation 26

5.3 Half shaft strength is stronger than core 26

5.3.1 Three possible conditions 26

5.3.2 Determination of semi-floating half-axis calculation load 26

5.4 Semi-axial structural design and materials and heat treatment 29

Chapter 6 Universal joint design 30

6.1 Universal joint structure selection 30

6.2 Universal joint material and heat treatment 31

Chapter 7 Design of Driving Axle Shell 31

7.1 Introduction to the axle housing 31

7.2 Design of the drive axle housing 32

conclusion 33

Thank 34

Chapter 1 Introduction

1.1 overview

The driving axle is at the end of the automobile transmission system. Its basic function is to increase the torque transmitted by the transmission shaft or directly by the transmission, distribute the torque to the left and right driving wheels, and make the left and right driving wheels have the differential function required by the kinematics of the automobile. At the same time, the driving axle also bears the vertical force, longitudinal force and lateral force acting on the road surface and between the frame or carriage.

In the general automobile structure, the drive axle includes the main reducer (also known as the main drive), differential, drive device for driving wheels and axle housing and other components.

The structure of driving axle is closely related to the suspension form of driving wheel. When the wheel is suspended independently, for example, on most trucks and some cars, the non-disconnected driving axle is used; when the driving wheel is suspended independently, the disconnected driving axle is used.

The general task of the automobile transmission system is to transfer the power of the engine so as to adapt it to the needs of the automobile. In the mechanical transmission of general automobiles, the contradiction between engine characteristics and driving requirements and the problem of structure arrangement can’t be completely solved with transmission (sometimes auxiliary transmission and transmission). Firstly, most of the engines are installed longitudinally in automobiles. In order to transmit the torque to the left and right driving wheels, the main reducer of the driving axle must change the direction of the transmission of the torque. At the same time, the differential of the driving axle must solve the problem of the distribution of the torque between the left and right driving wheels and the differential problem. Secondly, the main task of the transmission is to make the speed-torque characteristic of the internal combustion engine adapt to the power and economy requirements of the vehicle under various driving resistance by choosing proper gear number and transmission ratio, while the function of the main reducer of the drive axle (sometimes wheel-side reducer) is that when the transmission is in the highest gear position (usually in direct gear, sometimes in other cases). In overdrive, the car has enough traction, proper maximum speed and good fuel economy. Therefore, the power transmitted through the transmission and transmission shaft should be further increased by the main reducer of the driving axle to reduce the change of speed. Therefore, in order to make the design of automobile transmission system reasonable, first of all, it is necessary to properly select the total transmission ratio of the automobile, and properly allocate it to the transmission and drive axle. The deceleration ratio of the latter is called the main deceleration ratio. When the transmission is in the highest gear, the power and fuel economy of the vehicle mainly depend on the main deceleration ratio. In the general layout design of the vehicle, the appropriate main deceleration ratio should be selected according to the working conditions of the vehicle and the relevant parameters of the engine, transmission system and tire to ensure that the vehicle has good power and fuel economy. Due to the improvement of engine power, the reduction of vehicle quality and the improvement of road condition, the main deceleration ratio tends to be smaller. When choosing the main deceleration ratio, we should take into account that the vehicle can not only meet the requirements of high-speed driving, but also reduce the engine speed, reduce the consumption of suspected materials, improve the engine life and improve the vibration and noise within the range of commonly used speed.

The characteristics of sound.