Wuhan University of Technology

Graduate Design of Undergraduate

GJ1092A2D2 Long Head Diesel Truck Drive Axle Design

School： International Education

Class：Automotive Engineering gj1302

Student Name： Wencan Mao

Instructor: Xin Xiong

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Abstract

The main function of the drive axle is to increase the torque from the drive shaft or transmission, assign it to the drive wheels, and assure the left and right drive wheels have the differential function required by the car. In this paper, the structure plan of the drive axle assembly is firstly selected; followed by the main reducer design, including the selection of structure plan and main reduction ratio, the calculation of loads, the design of gears and bearings, etc., with the use of MATLAB software; the next is the differential design, including the selection of structure plan, the design of differential gears, strength check and so on; the following is the drive wheel transmission design, including the half axle strength calculation, structure design, selection of materials and heat treatment, etc.; and then the design of the drive axle housing, including the structure plan selection, strength calculation, material selection and so on. Finally, CATIA is used to model the gear structure of drive axle.

Key Words：Truck; Drive Axle Design; MATLAB; CATIA

Catalogue

Chapter1. Introduction 1

1.1 Purpose and Significance 1

• 1. Vehicle Analysis 1

Chapter2. Structure Plan Selection 3

Chapter3. Main Reducer Design 4

3.1 Structure of the Main Reducer 4

3.1.1 Gear Type of the Main Reducer 4

3.1.2 Supporting Form of the Driving Bevel Gear 5

3.1.3 Supporting Form of the Driven Bevel Gear 6

3.1.4 Deceleration Form of the Main Reducer 6

3.2 Basic Parameters of the Main Reducer 7

3.2.1 Determination of the Main Reduction Ratio 7

3.2.2 Determination of Calculation Load of Main Reducer Gear 7

3.3 Basic Parameters of the Main Reducer Gear 9

3.3.1 Selection of Teeth Number of Driving and Driven Bevel Gears 9

3.3.2 Selection of the Diameter and Transverse Module of the Driven Bevel Gear 10

3.3.3 Selection of Tooth Width of Hyperboloid Gear 10

3.3.4 Selection of Offset and Offset Direction of Pinion Hypoid Gear 11

3.3.5 Selection of Nominal Helix Angle 11

3.3.6 Selection of Spiral Direction 12

3.3.7 Selection of Normal Pressure Angle 12

3.4 Geometric Dimension of the Main Reducer Gears 13

3.5 Strength Calculation of the Main Reducer Gears 14

3.5.1 Calculation of Circumferential Force on Unit Tooth Length 14

3.5.2 Calculation of Bending Strength of Gear Teeth 15

3.5.3 Calculation of Tooth Surface Contact Strength 16

3.6 Material and Heat Treatment of the Main Reducer Gears 17

3.7 Calculation of the Main Reducer bearings 17

3.8 Lubrication of the Main Reducer 19

Chapter4. Differential Design 20

4.1 Structure of the Differential 20

4.2 Basic Parameters of the Differential Gears 20

4.2.1 Selection of Planetary Gear Number 20

4.2.2 Selection of Spherical Radius of Planetary Gear 20

4.2.3 Selection of Teeth Number of Planetary and Half Shaft Gears 21

4.2.4 Selection of Gear Modulus and Pitch Diameter of Half Shaft Gear 21

4.2.5 Selection of Pressure Angle 22

4.2.6 Selection of Diameter and Depth of Planetary Gear Mounting Hole 22

4.3 Calculation of Geometric Dimensions of Differential Gears 22

4.4 Strength Calculation of Differential Gears 24

Chapter5. Drive Wheel Transmission Design 26

5.1 Structure of the Half Shaft 26

5.2 Calculation of the Half Shaft 26

5.2.1 Determination of the Calculation Load 27

5.2.2 Determination of the Diameter of the Shaft 28

5.2.3 Strength Calculation of the Half Shaft 30

5.3 Material and Heat Treatment of the Half Shaft 29

Chapter6. Drive Axle Housing Design 30

6.1 Structure of the Axle Housing 30

6.2 Strength Calculation of the Axle Housing 31

6.2.1 Calculation of the Static Bending Stress 31

6.2.2 Strength Calculation under Impact Load of Rough Road 32