05 June 2016

PHASE 1

AUTOMATIC DIFFERENTIAL LOCKING SYSTEM


BACHELORS OF ENGINEERING
in

 AUTOMOBILE ENGINEERING


                  ACKNOWLEDGEMENT

At this pleasing moment of having successfully completed our project, we wish to convey our sincere thanks and gratitude to the management of our college and our beloved chairman M. V. Muthuramalingam  who provided all the facilities   to us.


We would like to express our sincere thanks to our principal , for forwarding us to do our project and offering adequate duration in completing our project.

We are also grateful to the Head of Department Prof. Balasubramaniam for His constructive suggestions & encouragement during our project.

With deep sense of gratitude, we extend our earnest & sincere thanks to our guide, Mr. Frank Gladson, Department of Mechanical engineering, for his kind guidance & encouragement during this project.

We also express our indebt thanks to our Teaching and Non Teaching staffs of Mechanical Engineering Department, of  Velammal  Engineering College.


TABLE OF CONTENTS


CHAPTER NO.                                TITLE                                                         PAGE NO.

                                             LIST OF FIGURES                                                         x
                                             LIST OF ABBREVIATIONS                                          xi
                  
           1.                             INTRODUCTION                                                              8
                                                   1.1  SYNOPSIS                                                          8
                                                   1.2 INTRODUCTION                                                  9
                                                         1.2.1  PROBLEM DEFINITION                             9
                                                         1.2.2  EXISTING MECHANISM                            9
                                                  1.3  FEASIBILITY STUDY                               
                                                         1.3.1 TECHNICAL FEASIBILITY                        10
                                                         1.3.2 ECONOMIC FEASIBILITY                         11
                                                         1.3.3 OPERATIONAL FEASIBILITY                    11
             2.                          LITERATURE SURVEY                                                    12 
              
                                2.1 DIFFERENTIAL WITH IMPROVED TRACTION                    12
                                       2.1.1  INTRODUCTION                                                         12 
                                       2.1.2  CHARACTERISTIC FUNCTIONS
                                       2.1.3   DIFFERENTIAL TORQUE TRANSFERS
                               2.2 LOKKA DISCUSSION – JOURNAL PAPER                              17
                                            2.2.1 DIFFERENCE TO A NORMAL DIFFERENTIAL      17
                                                    2.2.2  SIMPLE EXPLANATION OF
                                                               LOKKA'S OPERATION                                  19
                                            2.2.3 100% POSITIVE LOCKING MECHANISM           21
                                         2.3.3 AUTOMATED INTER-AXLE DLS
                                              ACTUATION  ENHANCEMENT – JOURNAL              
                                                 
                                                   2.3.3.1 INVEX GEARING                                       23
                                                   2.3.3.2 TORQUE BIAS RATIO                              24
                                                   2.3.3.3 STRUCTURE FOR ACHIEVING              26
                                                           TORQUE BIAS                                                
                                                   2.3.3.4 OVERALL BIAS CONTROL                     29
                                                   2.3.3.5 BIAS RATIOS BETWEEN
           DIFFERENT MODES
       
3.                    COMPONENTS AND DESCRIPTION                                                        30  
                                       3.1   WHAT'S A DIFFERENTIAL?
                                    3.1.1 THE FUNCTION OF A DIFFERENTIAL                 32
                                    3.1.2 TYPES OF DIFFERENTIALS
   
                           3.2 PNEUMATIC COMPONENTS
                                                3.2.1 PRODUCTION OF COMPRESSED AIR          34
                                                3.2.2 PNEUMATIC SINGLE ACTING CYLINDER  34
                                                3.2.1.1 CYLINDER TECHNICAL DATA                   34
                                                3.2.1.2 SOLENOID VALVE                                       35
                                               3.2.1.3 WORKING OF 3/2 SINGLE ACTING
                                                       SOLENOID VALVE                                           37
                                               3.2.1.4  FLOW CONTROL VALVE                            38                 
         
              4.           WORKING PRINCIPLE & DESIGN CALCULATIONS    40        
                                       4.1 WORKING PRINCIPLE                                                  41
                                       4.2 DESIGN AND DRAWINGS                                            42
                                               4.2.1 DESIGN OF PNEUMATIC CYLINDER                               
                                               4.2.2 DESIGN OF PISTON ROD                                      43
                                 
                                       4.3 TECHNICAL DATA                                                       45             
                                               4.3.1 SINGLE ACTING CYLINDER                                              
                                               4.3.2 3/2 SOLENOID VALVE                                           46
                                               4.3.3 FLOW CONTROL VALVE                                      48
 5.              PERFORMANCE OF DIFFERENTIAL UNIT                       52
                                              5.1 TORSION DIFFERENTIAL PERFORMANCE         54 
                                           5.2  VEHICLE TRAVEL ON STRAIGHT ROADS              57
                                        5.3 VEHICLE TRAVEL THROUGH TURNS                          58
                                   5.4 CENTER BOX APPLICATION                                             61
                                      5.5 CONCLUSION                                                                   65
             6.             COST ESTIMATION & CONCLUSION                                             66
             7.              REFERENCES                                                                                  69


LIST OF FIGURES

3.1.1        WORKING OF A DIFFERENTIAL UNIT                                           
4.1.1        BLOCK DIAGRAM OF THE WORKING UNIT
4.3.2        PNEUMATIC OPERATED SINGLE ACTING CYLINDER               
4.3.3       SOLENOID CONTROL VALVE                                                         
4.3.4       FLOW CONTROL VALVE                                                                  
4.3.5        ASSEMBLY LAYOUT OF THE AUTOMATIC DIFFERENTIAL
                UNIT LOCK SYSTEM                                          



LIST OF ABBERVIATIONS


            σy –         DESIGN STRESS in N/m2. 
                    
            d -       DIAMETER OF THE PISTON in  mm.
         
            ft –           WORKING STRESS in  N/m2.
   
                   t -       MINIMUM THICKNESS OF THE CYLINDER in  mm.

            ri -      INEER RADIUS OF THE CYLINDER in  mm.
            p -      WORKING PRESSURE  in  N/m2.
          
           dp  -         DIAMETER OF THE PISTON ROD in  mm.





CHAPTER – 1

1.1 SYNOPSIS
The proposed mechanism is to lock the differential. By locking the differential the differential is disengaged from the axle. Thus the power is directly transmitted to the axle and hence to the wheels. This will considerably reduce the power loss in some occasions when unwanted loss is happening due to the transmission if power from the shaft to the differential and then to the axle and hence to the wheels. So in mechanism the unwanted power loss in the due course of transmission through the differential is reduced.                  
There are some drawbacks in the existing mechanism and we overcome it in the proposed project. The first is while climbing in steep hills the differential is not really needed as the speed of the vehicle is low. And also there are some transmission loses in the differential. So at this time the unit is locked and the loss is overcome. Then when a heavy truck is struck in a pit or mud it is very difficult to recover the truck as the differential unit cuts the power which is to be transmitted to the wheel struck. So in this project the unit is disengaged and power is directly given to the axle by pneumatic means and so the recovery is made easier. This is even made use in the vehicle to be driven in the dense forests and even in dessert.

     1.2 INTRODUCTION

1.2.1 PROBLEM DEFINITION

EXISTING MECHANISM
A differential is a device which is used in vehicles over a few decades and when a vehicle is negotiating a turn, the outside wheel travels a greater distance and turns faster than the inside wheel. The differential is the device transmitting the power to each wheel, allows one wheel to turn faster than the other. It splits the engine torque two ways, allowing each output to spin at a different speed. The differential is found on all modern cars and trucks, and also in many all-wheel-drive (full-time four-wheel-drive) vehicles.
These all-wheel-drive vehicles need a differential between each set of drive wheels, and they need one between the front and the back wheels as well, because the front wheels travel a different distance through a turn than the rear wheels. Part-time four-wheel-drive systems don't have a differential between the front and rear wheels; instead, they are locked together so that the front and rear wheels have to turn at the same average speed. This is why these vehicles are hard to turn on concrete when the four-wheel-drive system is engaged.




to be continue in phase 2 ...!!!!!














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