Graduation Design (Thesis) of Wuhan University of Technology

Design of Active Radial Bogie Frame Based on DF (8B) Type Three Axle Locomotive

School: International Education College

Specialty amp; Class: Vehicle Engineering Class 1302

Student name: Wang Piao

Tutor: Xu Lin

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Abstract

The DF (8) B locomotive introduced, digested and absorbed some of the HTCR radial bogies from the United States during the course of its development, and made new progress in the research work of bogies in China.But up to now, many bogies in the world have been used for self steering,it drives the radial adjustment mechanism through the creep sliding moment between the wheel and rail,but the self steering bogie will suffer greater energy losses during the kinematic coupling of the end wheel-set, and the steering angle is not accurate enough to accelerate the unnecessary wear between the wheel and rail.The active radial bogie has broken the traditional radial bogie work, through computer control system, analyzing the curve passing path . Further, the direction of the radial mechanism is adjusted. Meanwhile,it can balance creep force between wheel and rail to achieve the optimal steering effect.

Key Words：Radial bogie；Active radial；Framework；Radial mechanism

Contents

Abstract I

Chapter 1 Introduction 1

1.1 Research background and significance 1

1.2 Brief introduction of radial bogies 2

1.2.1 Principle of radial bogie 2

Chapter 2 Design of Active Radial Steering Frame 5

2.1 Design of main frame 5

2.2 Design of sub frame 7

Chapter 3 Structure Analysis of Active Radial Steering Frame 9

3.1 Static strength analysis of main frame 9

3.2 Static strength analysis of sub frame 13

3.3 Optimization model 22

3.4 Summary of this chapters 26

Chapter 4 Design of an Active Radial Adjustment Device 27

4.1 Reasonable spatial arrangement 27

4.2 Design of an active radial mechanism 27

4.3 Selection of roller screw and motor 29

4.3.1 Selection of roller screw 30

4.3.2 Motor selection 31

Chapter 5 Conclusion 33

References 35

Appendix 37

Acknowledgment 39

Chapter 1 Introduction

1.1 Research background and significance

From the beginning of the founding of China, the locomotive bogie has been in continuous evolution. By now, the main line of the highest speed is up to 180km/h, however, people are still in the pursuit of higher speed, the open line of mangle suspension train is embodied. Therefore, the arrival of the sixth railway speed can also be predicted. As one of the most important parts of the locomotive, the development of a new type of high speed bogie can find a new breakthrough in the speed limit. The use of the new bogie and the application of advanced technology, will greatly improve the operational convenience of the vehicle. Various parameters of the bogie can play a direct role in the stability and ride comfort of the vehicle . A good bogie not only can improve the locomotive running speed, but also can ensure the safety of the locomotive, improve the operation quality, improve the comfort and reduce the environmental pollution . China's locomotive industry started relatively late, and by 1950s, China had designed its own bogies --Y25 bogies for the first time, this is a welded frame type self steering radial bogie. After then,Chinese experts were constantly importing advanced technology from abroad, in the end of 90s, on the basis of radial bogie has been widely used, China leased a X2000 tilting train from Swedish in 1998. According to the characteristics of our own, in 1999, China developed the first tilting train with independent intellectual property rights . In 2002, China's first 220km/h high-speed passenger car bogies successfully carried out line dynamic test.

The earliest radial bogies of the world can date back to the nineteenth Century, when the carriages used a cross braced structure, the predecessor of the bogies. By the 70s of last century, South African Railway engineers designed self steering radial bogies on the transport cars, which officially opened the prelude to the development of radial bogies.Later, the radial bogies began to be further improved in countries such as North America and Japan, meanwhile,DR-1, DR-2 Bogies, Devine-Scale bogies in the United States and Frame-Braced bogies of British are all begin to be popularized.

According to the foreign related data show that the radial bogie angle on the small radius curve can be reduced to the traditional bogie below 1/3, the lateral force can be reduced nearly half, while the adhesion coefficient curve can reach 0.3 (maximum starting adhesion coefficient is more than 0.4), round edge friction reduced 20%.The use of radial bogie greatly solved the problem between wheel and rail wear engineer stores, and significantly improved the adhesive performance, especially in the three axle locomotive heavy transport steering rack through small curve and the curve of the traction ability and speed. There were some typical radial bogie structure in foreign countries, such as radial bogie for E120 locomotive in Germany, steering frame on Swiss Re4/4 and 460 series locomotives, HTCR radial bogie on American SD60MAC Series Locomotive and so on.

Because of the large number of China's mountains, built railway lines are mostly winding curves. In order to meet the requirements of high speed and heavy load, as far as possible to reduce the cost of railway maintenance, the development of a new type of three axle radial bogie has become the inevitable trend of the times. Combined with the characteristics of various forms of radial bogie, the situation of China and the actual situation of the factory, Chinese locomotive bogie DF is similar to the radial bogie for HTCR locomotive, therefore, the structural form of HTCR radial bogie is used for reference.On this basis, we can make further improvement on the active radial bogie of three axle locomotive and optimize it.

1.2 Brief introduction of radial bogies

1.2.1 Principle of radial bogie

The radial bogies are based on that conventional bogies could not change the thrust angle between wheel set and rail when the curve is passed. The radial bogie establishes a bar structure between the wheel set and eliminates the shake head restraint of the end wheel set. The free rotation of the end wheel set is favorable for the locomotive to rotate the radial mechanism under the creep sliding moment of the wheel and rail during the passing of the curve so as to achieve the radial position of the wheel set.

Radial bogies can be divided into two major categories: forced steering and self guided steering. Nowadays, many of the products on the market are self guided radial bogies, because radial steering engines are more simple than radial bogies. The working principle of the self guided radial bogies is that the front and rear wheel set of the bogie is connected by a radial pull rod, and the shaking head restraint of the wheel set is simultaneously relieved, and the steering function of the bogie is simply supported by the creep torque between the wheel and rail. The force transfer direction of self steering radial bogie is controlled by the torque generated by the path curve to the wheel, and the deflection of the radial mechanism is controlled, and then the feedback is used to control the steering of the wheel set. This bottom-up force transmission route is too complex, especially when the wheel set enters the curve path, there will still be considerable friction loss between the wheel and rail. When bogie of this kind of locomotive passes through the curve path, the bar structure between the bogies will rotate the front and rear wheels at the same time and tend to the position of steering so as to smoothly pass through the curve. This also means that the wheel alignment of the radial bogie is very serious, so wear resistant material must be used as the tread, and the wheel should be elastic connected directly with each other.The minimum radius of the radial steering bogie shall not be less than 600m..