chuyên đề hệ thống truyền lực bản tiếng anh

chuyên đề hệ thống truyền lực khoa công nghệ ô tô trường đại học công nghiệp hà nội tính toán hộp số cơ khí 5 tiến 1 lùi xe toyota vios 2021 1.1. Reasons for choosing the topic In Group 1, we chose the research topic on mechanical gearboxes for the following purposes: In order to apply knowledge about the structure, the principle of movement of mechanical gearboxes to apply and calculate and analyze. Present the principle of operation, structure, details and assemblies of mechanical gearboxes. In order to analyze, evaluate and compare the development trend of mechanical gearboxes compared to automatic or stepless automatic transmissions. With the strong development of informatics in the leading role, automation has penetrated deeply into manufacturing industries and their products, one of which is automobiles, not only making users feel comfortable, close to their cars, Show the style of the person who owns them. But automation also improves the safety factor in use. This is why automatic systems are always equipped for highend cars and gradually applied to popular vehicles. Therefore, with the chosen topic of research, survey of mechanical gearboxes, we hope that this topic will better consolidate the knowledge that has been passed on so that when we graduate, we can participate in Vietnams automobile industry, contributing to the overall development of the industry. The content of the big exercise consists of 3 parts: PART 1: PROLOGUE PART 2: RESEARCH RESULTS PART 3: CONCLUSIONS AND LESSONS LEARNED. The content of the big exercise was completed under the guidance of Mr. Bui Van Hai, Faculty of Automotive Technology, Hanoi University of Industry 1.2. Objectives of the project Surveying mechanical gearboxes helps us equip more about the structure and working principle of a specific mechanical gearbox in terms of gear ratio creation mechanism. In addition, the topic also helps us see the repair inspection process of vehicles equipped with mechanical transmissions, from how to receive complaints from users to the vehicle testing process to identify the area where the failure occurs and parts that may occur. This helps us not only understand the features and principles of a mechanical transmission but also help us repair it and pay appropriate attention when using vehicles equipped with mechanical transmissions.

TABLE OF CONTENTS

LIST OF TABLES 5

IMAGE BIBLIOGRAPHY 6

TABLE OF CONTENTS 7

LIST OF TABLES 10

IMAGE BIBLIOGRAPHY 11

PART 1 BEGIN 12

1.1 Reasons for choosing the topic 12

1.2 Objectives of the project 12

PART 2 RESEARCH RESULTS 14

2.1 Overview of mechanical gearboxes 14

2.1.1 The history of the development of mechanical gearboxes in cars: 14

2.1.1.1 Basic changes of mechanical gearbox: 14

2.1.1.2 The development of mechanical gearboxes and its role in the powertrain: 15

2.1.1.3 Development stages of mechanical gearboxes: 16

2.1.1.4 Common types of mechanical transmissions in cars: 17

2.1.1.5 The development of components and mechanisms in mechanical gearboxes: 18

2.1.2 Basic elements of a mechanical transmission in a car: 20

2.1.2.1 Principle of operation of mechanical gearbox: 20

2.1.2.2 Main and auxiliary functions of mechanical gearboxes: 21

2.1.2.3 The relationship between revolutions, gear ratio and torque in mechanical gearboxes: 22

2.1.2.4 Impact of mechanical transmission on driving mode and vehicle performance: 23

2.1.2.5 Advantages and limitations of mechanical gearboxes: 24

2.1.3 New features and technologies in mechanical gearboxes: 25

2.1.3.1 Clutch systems and actuators in mechanical gearboxes: 25

2.1.3.4 Advanced technologies in mechanical gearboxes: 27

2.1.4 Developments and trends in mechanical transmissions in cars: 27

2.1.4.1 Improved performance and fuel efficiency in mechanical gearboxes: 27

2.1.4.2 Integration of intelligent and connected technologies in mechanical gearboxes: 28

2.1.4.3 Direction of mechanical gearbox technology in the future: 29

2.2 Force to choose the design plan and design the calculation of the gearbox 29

2.2.1 Selection of design plan 29

2.2.2 Gearbox calculation design 31

2.2.2.1 Calculation of the gear ratio 31

2.2.2.2 Determine the No 1 hand transmission ratio 32

2.2.2.3 Calculation of the basic parameters of gears 33

2.3 Gearbox wheel durability 38

2.3.1 Payload mode 38

2.3.1.1 Gear durability 39

2.3.2 Calculation of the gearbox shaft 41

2.3.2.1 Choosing shaft material 41

2.3.2.2 Preliminary calculation of gearbox shaft dimensions 41

2.3.2.3 Axial strength 41

2.3.3 Rolling bearing calculation 47

2.4 Durability of the No 2 gear pair on the Inventor 49

2.5 Check maintenance and repair of gearbox 55

2.5.1 Repair inspection 55

2.5.1.1 Check the gearbox housing 55

2.5.1.2 Check the tooth surface of the gears 55

2.5.1.3 Inspection of bearings 55

2.5.1.4 Check the accelerator mechanism 55

2.5.1.5 Check the gear lever 55

2.5.1.6 Check the lever fork 56

2.5.1.7 Check the positioning mechanism and the two-digit anti-mounting

mechanism 56

2.5.2 Attention when disassembling 56

2.5.2.1 Attention when removing 56

2.5.2.2 Attention when mounting 56

PART 3 CONCLUSIONS AND LESSONS LEARNED 57

3.1 Knowledge 59

3.2 Skills 59

3.3 Attitude 59

3.4 Lessons learned 60

BIBLIOGRAPHY 61

BIBLIOGRAPHY 62

LIST OF TABLES

Table 2.1: Working states of gearbox 30

Table 2.2: Calculation data table 31

Table 2.3: Number of teeth of active and passive gears 34

Table 2.4: Correct gear ratios in gear handles 35

Table 2.5: Precision shaft spacing at gear arms 35

Table 2.6: Table of coefficient of adjustment of each pair of gears 37

Table 2.7: Basic dimensions of forward gears 37

Table 2.8: Basic dimensions of reverse gears 38

Table 2.9: Force acting on gears 39

Table 2.10: Bending stress value at each gear 40

Table 2.11: Contact stress values at each pair of gears 41

Table 2.12: Distance of force setpoints (N) 43

Table 2.13: Jets at support pillows (N) 44

Table 2.14: Moment at force setpoints (Nmm) 45

Table 2.15: Equivalent torque at force setpoints (Nmm) and diameter selection calculation d (mm) 46

Table 2.16: Glass guide load (N) 48

Table 2.17: Rtd equivalent force (N) and calculated dynamic load capacity C (kN) 49

IMAGE BIBLIOGRAPHY

Figure 2.1: Diagram of a 5-speed gearbox 20

Figure 2.2: Number hand 21

Figure 2.3: Diagram of a 5-speed 2-axis gearbox 30

Figure 2.4: General force laying diagram for number hands from 1 to 4 42

Figure 2.5: General force laying diagram for hand 5 42

Figure 2.6: Axis torque chart 1(left), axis 2(right) hands 1 to 4 44

Figure 2.7: Axis torque diagram 1(left), axis 2(right) hand No 5 45

TABLE OF CONTENTS

LIST OF TABLES 5

LIST OF IMAGES 6

PART 1 INTRODUCTION 7

1.1 Reason for choosing topic 7

1.2 Objectives of implementing topic 7

PART 2 RESEARCH RESULTS 9

2.1 Overview of mechanical gearboxes 9

2.1.1 History of development of mechanical transmissions in cars: 9

2.1.1.1 Basic changes of mechanical gearbox: 9

2.1.1.2 The development of the mechanical gearbox and its role in the power transmission system: 10

2.1.1.3 Stages of development of mechanical gearboxes: 11

2.1.1.4 Common types of mechanical transmissions in cars: 12

2.1.1.5 Development of components and mechanisms in mechanical gearboxes: 13

2.1.2 Basic elements of mechanical transmissions on cars: 15

2.1.2.1 Operating principle of mechanical gearbox: 15

2.1.2.2 Main and auxiliary functions of mechanical gearbox: 16

2.1.2.3 Relationship between number of revolutions, gear ratio and torque in mechanical gearbox: 18

2.1.2.4 Impact of mechanical transmission on driving mode and vehicle performance: 18 2.1.2.5 Advantages and limitations of mechanical gearboxes: 19

2.1.3 New features and technologies in mechanical gearboxes: 20

2.1.3.1 Clutch and transmission systems in mechanical transmissions: 20

2.1.3.2 Mechanical transmission and performance enhancing technology: 21

2.1.3.3 Automatic and semi-automatic transmission systems: 21

2.1.3.4 Advanced technologies in mechanical gearboxes: 22

2.1.4 Developments and trends in mechanical transmissions in cars: 23

2.1.4.1 Improved performance and fuel efficiency in mechanical transmissions: 23

2.1.4.2 Integrating smart and connected technologies in mechanical gearboxes: 23

2.1.4.3 Future direction of mechanical gearbox technology: 24

2.2 Force for selecting design options and designing and calculating gearbox 25

2.2.1 Select design option 25

2.2.2 Design and calculation of gearbox 26

2.2.2.1 Calculate gear ratio 27

2.2.2.2 Determine the 1st gear ratio 27

2.2.2.3 Calculate basic parameters of gear 29

2.3 Durability of gear box 34

2.3.1 Load mode 34

2.3.1.1 Gear durability 35

2.3.2 Calculate gearbox shaft 37

2.3.2.1 Select shaft material 37

2.3.2.2 Preliminary calculation of gearbox shaft size 37

2.3.2.3 Axial durability 37

2.3.3 Bearing calculation 43

2.4 Check the durability of the number 2 gear pair on the Inventor 45

2.5 Check, maintain and repair gearbox 51

2.5.1 Check and repair 51

2.5.1.1 Check box number 51

2.5.1.2 Check the tooth surface of gear 51

2.5.1.3 Check bearings 51

2.5.1.4 Check the synchronizer mechanism 51

2.5.1.5 Check gear lever 51

2.5.1.6 Check the lever 52

2.5.1.7 Check the positioning mechanism and the two-digit anti-engagement mechanism 52

2.5.2 Pay attention when disassembling 52

2.5.2.2 Pay attention when installing 52

PART 3 CONCLUSION AND LESSONS LEARNED 53 3.1 Knowledge 55

3.2 Skill 55

3.3 Attitude 55

3.4 Lessons learned 55

REFERENCES 56

LIST OF TABLES

Table 2.1 Working states of gearbox 26

Table 2.2 Calculation Data Sheet 26

Table 2.3 Number of teeth of active, passive gears 30

Table 2.4 Precision gear ratios in gear hands 30

Table 2.5 Precision shaft spacing at the number arms 31

Table 2.6 Table of translation coefficients for each pair of gears 33

Table 2.7 Basic dimensions of forward gears 33

Table 2.8 Basic dimensions of reverse gears 34

Table 2.9 Force acting on gears 35

Table 2.10 Bending stress values at each gear 35

Table 2.11: Contact stress values at each pair of gears 37

Table 2.12 Force setpoint distances (N) 39

Table 2.13 Jets at Pillows (N) 40

Table 2.14 Moment at force setpoints (Nmm) 41

Table 2.15 Equivalent torque at force setpoints (Nmm) and diameter selection calculation d(mm) 42

Table 2.16 Glass Guide Load (N) 44

Table 2.17 Rtd equivalent force (N) and calculated dynamic load capacity C (kN) 45

IMAGE BIBLIOGRAPHY

Figure 2.1: Diagram of the 5-speed 20 gearbox Figure 2.2: Hand No 21 Figure 2.3: Diagram of the 30-speed 5-axis 2-axis gearbox Figure 2.4: General force laying diagram for numbers 1 to 4 42 Figure 2.5: General force laying diagram for hand number 5 42 Figure 2.6: Axis torque diagram 1(left), axis 2(right) hands No 1 to 4 44 Figure 2.7: Axis torque chart 1(left), axis 2(right) hand No 5 45

PHẦN 1 BEGIN 1.1 Reasons for choosing the topic

In Group 1, we chose the research topic on mechanical gearboxes for the followingpurposes:

-In order to apply knowledge about the structure, the principle of movement ofmechanical gearboxes to apply and calculate and analyze

-Present the principle of operation, structure, details and assemblies ofmechanical gearboxes

-In order to analyze, evaluate and compare the development trend ofmechanical gearboxes compared to automatic or stepless automatic transmissions With the strong development of informatics in the leading role, automation haspenetrated deeply into manufacturing industries and their products, one of which isautomobiles, not only making users feel comfortable, close to their cars, Show the style

of the person who owns them But automation also improves the safety factor in use.This is why automatic systems are always equipped for high-end cars and graduallyapplied to popular vehicles Therefore, with the chosen topic of research, survey ofmechanical gearboxes, we hope that this topic will better consolidate the knowledge thathas been passed on so that when we graduate, we can participate in Vietnam'sautomobile industry, contributing to the overall development of the industry

The content of the big exercise consists of 3 parts:

-PART 1: PROLOGUE

-PART 2: RESEARCH RESULTS

-PART 3: CONCLUSIONS AND LESSONS LEARNED

The content of the big exercise was completed under the guidance of Mr Bui VanHai, Faculty of Automotive Technology, Hanoi University of Industry

1.2 Objectives of the project

Surveying mechanical gearboxes helps us equip more about the structure and

vehicles equipped with mechanical transmissions, from how to receive complaints fromusers to the vehicle testing process to identify the area where the failure occurs and partsthat may occur This helps us not only understand the features and principles of amechanical transmission but also help us repair it and pay appropriate attention whenusing vehicles equipped with mechanical transmissions

PHẦN 2.RESEARCH RESULTS 2.1 Overview of mechanical gearboxes

2.1.1 The history of the development of mechanical gearboxes in cars:

2.1.1.1 Basic changes of mechanical gearbox:

The mechanical gearbox (also known as mechanical transmission, hydraulicgearbox or mechanical gearbox) has undergone many changes and improvementsthroughout its development history Here are some important fundamental changes:

- Gear level: Initially, the mechanical gearbox had only a single gear level,meaning that it could only switch between two states: forward and backward However,over time, the gearbox has been improved to be able to switch between many differentgear levels The gearbox number is usually represented by a number, for example 4, 5 or

6 gear levels, depending on the type of gearbox

- Internal mechanism: The mechanism inside the mechanical gearbox hasundergone many changes to both improve performance and durability The design ofcomponents such as serrations, gears, drive shafts and clutches has been optimised toprovide smooth and precise transitions between gear levels

- Synchronization mechanism: Synchronization is an important component inmechanical gearboxes It helps the gears and drive shafts to be connected consistently,ensuring smooth transmission and avoiding slipping or sucking each other Thesynchronization mechanism has been improved to increase accuracy and durability

- Improved performance: New technologies have been applied in mechanicalgearboxes to improve performance and save energy For example, using lightweight andhigh-quality materials in gearbox manufacturing can reduce weight and increaseaccuracy The lubrication and cooling systems have also been improved to increase thelife and performance of the gearbox

- Integrated electronic technology: Electronic technology has been integrated inthe mechanical gearbox to provide automatic functions, mode selection, electroniccontrol system

- Dual gearbox: Some advanced mechanical gearboxes have been equippedwith dual transmissions Instead of having just one pair of gears, dual gearboxes use two

pairs of parallel gears to provide additional gear level This allows for smoothertransitions and increased gearbox flexibility

- Load balancing system: Today's mechanical gearboxes are often equippedwith a load balancing system, which distributes the load force evenly to the gears andcomponents in the gearbox This increases the service life and durability of the gearbox,while improving performance and smooth transmission

- Automatic transmission: Another major improvement of mechanicaltransmissions is the appearance of automatic transmissions Automatic transmissions use

a power or electronic system to automatically switch between gear levels, reducingdriver intervention and providing an easier driving experience

- Smart technology integration: Some modern mechanical gearboxes areintegrated with intelligent technology, including automatic control systems, sport drivingmodes and fuel economy modes These technologies help customize performance anddriving experience according to driver preferences

2.1.1.2 The development of mechanical gearboxes and its role in the powertrain:

The mechanical transmission has undergone significant development through thestages and plays an important role in the vehicle's powertrain Here's an overview of theevolution of mechanical gearboxes and their role in powertrains:

- Classic mechanical transmission: Initially, cars used simple mechanicaltransmissions with one forward and one reverse gear levels This gearbox allows power

to be adjusted from the engine to the wheels through gears, rollers and tapers It plays amajor role in driving from the engine to the active drive system (main drive shaft or rearaxle)

- Increased gear levels: With the development of technology and operatingrequirements, mechanical gearboxes have been improved by increasing gear levels.Increasing gears in mechanical transmissions provides a wider speed range and helpsoptimize engine performance under different driving conditions This can be achieved byadding the right actuators and gears

- Other innovative technologies: In addition to increasing gear levels,mechanical gearboxes have also undergone other improvements such as improvedmaterial quality, increased machining accuracy, fuel-efficient design, and reduced

friction This boosts the overall powertrain performance and reduces the vehicle's fuelconsumption

- Integrated electronic technology: Electronic technology has been integrated inthe mechanical gearbox to provide automation functions and increase the intelligence ofthe system Functions such as automatic mode, intelligent driving mode and electroniccontrol system have been added to the mechanical transmission to enhance performanceand driving experience

The mechanical transmission plays an important role in the car's powertrain Itsmain role is to drive from the engine to the active drive system (main or rear drive shaft)and regulate the power transmitted to the wheels Here are the main roles of mechanicalgearboxes in the powertrain:

- Torque and power adjustment: The mechanical gearbox allows adjustment oftorque and power from the engine to the wheels By selecting the right gear level, thetransmission can increase or decrease the torque and power transmitted from the engine

to the active drive, depending on the operating conditions and driver requirements

- Provides a wide speed range: The mechanical transmission allows to provide

a wide speed range for the vehicle By having multiple gear levels, the gearbox providesspeed adjustment and provides optimum power in different road situations The widespeed range makes it possible to move from low speed to high speed efficiently

- Provides reverse gear: The mechanical transmission provides a reverse gear,allowing the vehicle to move in reverse Reverse gear makes parking or moving in theopposite direction easy and convenient

- Increased efficiency and fuel economy: Mechanical gearboxes can bedesigned to optimize performance and fuel economy By adjusting the gear levelaccordingly, the gearbox keeps the engine operating in the optimal velocity and loadrange, increasing efficiency and reducing fuel consumption

2.1.1.3 Development stages of mechanical gearboxes:

Mechanical gearboxes have gone through important stages of development in theevolution of the automotive industry Here are some notable stages of development ofmechanical gearboxes:

- First stage: Early mechanical transmissions were simple gearboxes withlimited gear levels, usually 2 or 3 gear speeds During this period, mechanical gearboxeswere used mainly in the first types of cars and were not fully optimized for performance

- Stage of increasing gear levels: As technology and operating requirementshave evolved, mechanical gearboxes have been improved by increasing gear levels.Instead of only having 2 or 3 gear speeds, the mechanical transmission has beenupgraded to 4, 5, 6 and possibly more The increase in gear increases the speed range andimproves performance and fuel economy

- Electronic technology integration stage: Another important development ofmechanical gearboxes is the integration of electronic technology Electronic technology

is used to improve the performance and performance of gearboxes Modern mechanicalgearboxes often integrate electronic control systems, intelligent driving modes andautomatic modes Electronic technology enhances the driving experience and improvesthe responsiveness and performance of the transmission

- Stage of optimizing performance and driving experience: Car manufacturerscontinuously research and develop mechanical gearboxes to optimize performance anddriving experience They focused on improving material quality, reducing friction,increasing machining precision, and improving the overall design of gearboxes The goal

is to create lightweight, efficient and smooth mechanical transmissions to provide thebest driving experience

- The next stage in the development of mechanical gearboxes is to optimizeperformance and driving experience Automakers are focusing on improving variousaspects of gearboxes to meet the increasing demands of users

- Improved material quality: The manufacturing technology and materials used

in the gearbox have been enhanced to increase durability, reduce weight and ensuresmooth operation throughout the life of the gearbox Using materials such as high-strength steel, aluminum alloy and carbon fiber has improved the mechanical propertiesand bearing strength of the gearbox

- Reduced friction: The elements inside the gearbox are designed to reducefriction and energy loss Using anti-friction materials, precision-machined parts andeffective lubrication use reduce friction and increase gearbox performance

- Increased machining accuracy: The machining and assembly processes of thegearbox have been improved to achieve high precision This ensures a perfect matchbetween components and minimizes vibration and noise during operation

- Overall design improvements: The overall design of the gearbox is optimized

to increase powertrain, reduce size and weight, and provide a smoother drivingexperience Using technologies such as streamlined cutting gears, a good clutchmechanism and a precision gear lever system has contributed to the improvement ofperformance and driving experience

2.1.1.4 Common types of mechanical transmissions in cars:

Depending on the criteria, mechanical gearboxes are classified as follows:

- According to the state of the gearbox shaft during work

+ Gearbox with fixed shaft

+ Gearbox with mobile shaft (planetary gearbox)

- According to the axis of the gearbox (excluding the reverse axis)

+ By brake and clutch (for hydromechanical gearbox)

2.1.1.5 The development of components and mechanisms in mechanical gearboxes:

Likened to the heart of the powertrain, the transmission transforms the torque, theworking speed of the engine to suit the working conditions of the wheels on the road.Since George Selden's famous invention of front-wheel drive combined with ahorizontally placed 3-cylinder engine became a car design, few new ideas have fit

Introduced in 1894, the first sketch of the modern gearbox by two Frenchengineers, Louis-Rene Panhard and Emile Levashor, did not bring them glory but insteadreceived criticism

The presentation was unsuccessful, the model car stalled, the content was truncated

to be presented only on the blackboard One newspaper wrote that "the charlatan usedmany tricks to deceive the public with the new car." Perhaps inventors should skip thetech talk and use the description just enough What they did was gross

At that time, the drive structure was quite simple with a belt transmission or taperedgear transmission The car can only run at a maximum speed of 32 km/h Whenencountering obstacles on the road, the driver must stop in low gear

F W Lanchester, one of the pioneers of automobiles in England, described his car

as consisting of two belt transmission levels, one for low speeds, requiring large torqueand one for high speeds, small torque

A year after the infamous press conference, the famous Panhard and Levassorreturned not only with the transmission itself, but also the entire powertrain This time,they had their first car ready to run when stepping on the accelerator Besides, they havealso made a lot of changes in ideas In fact, it is a model that has met most of therequirements of cars built in the 90s and also in later years

Unlike the current model, the new design has an engine located along the front,transmitting power to the rear axle via a clutch and a 3-speed sliding gearbox and chain-driven bridge It is almost the same as the powertrain on modern cars, but without anactive differential and semi-axle However, in 1898, this became a reality whenmillionaire Louis Renault successfully connected power from the longitudinal engine,through the gearbox to the "live" rear axle using a metal shaft

The "live" rear axle, or rear differential, was something Renault did in line with theidea developed by an American named C E Duryea in 1893 Since it overcame theproblem of tire wear, this invention was adopted by most automakers The differentialconsists of an articular gear assembly that is responsible for dividing power between thetwo wheels of the rear axle It allows the outer wheel to spin faster than the wheel whilethe car rotates

In 1904, the manual transmission of the slip shift of Panhard-Levassor was realized

by most automakers Whether they exist in one form or another, they are still in use untilrecent times Obviously, there have been improvements, the most important changebeing the synchronization system that allows the process of matching the gear waysmoothly, without shocks Gearboxes equipped with accelerators were first used byCadillac in 1928 After being developed by Porsche, this invention has become popular

to this day

The period between the appearance of the manual transmission and the moment ofthe invention of the accelerator, there was another attempt to simplify the process ofshifting gears It is a gearbox made of a planetary gear transmission, which first appeared

on the 1908 Ford Model T

The planetary gear transmission consists of a central gear or also known as a solargear, several planetary gears that fit around Today, planetary transmissions are usedmore on automatic transmissions than on manuals

Several types of complex manual gears using planetary gears have been introduced,the Wilson Preselector being one such transmission It used to be used in the 30s Thesystem uses 4 separate planetary gear transmissions, allowing the driver to pre-select agear ratio by moving the small joystick next to the steering axle

2.1.2 Basic elements of a mechanical transmission in a car:

2.1.2.1 Principle of operation of mechanical gearbox:

5-speed gearbox:

The gearbox belongs to the mechanical type with 5 gear levels, including 5 forwardand 1 reverse gear It works as follows:

+ Number 1:

We flipped the rear joystick so that the number 1 gear matched the number 10 gear

At this time the torque from the engine passes through the digital primary shaft (I), to 5thgear, through 6th gear to the digital intermediate shaft (III), to 10th gear, to 1st gearthrough the digital secondary shaft (II) and transmitted to the rear powertrain

+ Number 2:

We flip the rear joystick so that the accelerator ring B matches gear 2 At this time,the torque from the engine passes through the primary shaft number (I), to gear 5, gear 6

to the intermediate shaft number (III), to gear 9, to gear 2, through the accelerator ring B,

to the secondary shaft number (II) and transmits to the rear powertrain

+ Number 3:

We flip the rear joystick so that the B accelerator ring matches gear 3 At this timethe torque from the engine passes through the digital primary shaft (I), to gear 1, throughgear 6 to the intermediate shaft number (III), through gear 8, through gear 3, through theaccelerator ring B, to the secondary shaft number (II) and transmitted to the rearpowertrain

through gear 6 to the intermediate shaft (III), through gear 7, to gear 4, through theaccelerator ring A, to the secondary shaft number (II) and transmitted to the rearpowertrain

+ No 5:

We flip the rear joystick so that the accelerator ring A matches gear 5 At this time,the torque from the engine passes through the primary shaft number (I) to gear 5, throughthe co-speed ring A transmits to the secondary shaft number (II) and transmits to the rearpowertrain

+ Reverse gear:

We flip the rear joystick so that gear 11 matches gear 10 At this time the torquefrom the engine passes through the digital primary shaft (I), through gear 6 to the gearintermediate shaft (III), to gear 10, through gear 11, to the reverse gear shaft, to gear 12,

to gear 12, to gear 1, through the secondary shaft number (II) and transmitted to the rearpowertrain

2.1.2.2 Main and auxiliary functions of mechanical gearboxes:

The gearbox converts the rotational energy of the motor into the appropriaterotational speed for the wheels Mechanical gearboxes do so with simple gears.Automatic transmissions use more complex planetary gears

The engine of a car cannot be attached directly to the wheel Car engines can onlyoperate in a relatively small RPM range, and the maximum speed they can achieve in thisrange is quite low The gearbox changes the ratio between the rotational speed of theengine and the speed of rotation of the wheels At low speeds, cars rely on small gears

At higher speeds, larger gears are required

Manual transmissions require the driver to select gears to use manually On theother hand, the automatic transmission will automatically switch to new gears When thespeed of the engine drops in an automatic car, its gear shifting is being changed.Traditionally, manual transmissions are significantly more efficient than automatictransmissions Modern automatic transmissions are much more efficient

Some new cars rely on a continuously variable transmission, which moves the belt

or chain along the cone to always deliver the ideal gear ratio Electric cars do not needgearboxes because electric motors can operate in a wide RPM range and in-wheel motors

do not need different gears that are expected to hit the market in the coming years

A mechanical transmission (also known as a mechanical transmission) is animportant part of a vehicle's powertrain The main function of a mechanical transmission

is to regulate the speed and torque between the engine and the wheels To do this, thegearbox uses parts such as gears, camshafts, clutch discs and transmission shafts

In particular, mechanical gearboxes have the following functions:

Form 2.2: Hand number

- Speed adjustment: The mechanical transmission can control the unique inch

of the engine to suit the road conditions It offers many gears of different sizes, whichallows the output speed of the wheel hub to be adjusted

- Torque adjustment: The mechanical transmission can also adjust the torquebetween the engine and wheels It can reduce torque to ensure a stable speed when thecar is on a flat road or increase torque to help the vehicle overcome mountainous terrain

or heavy loads

- Power supply to the vehicle: The mechanical transmission provides power tothe vehicle through the drive shaft and other parts of the powertrain

In addition, the mechanical gearbox has the following auxiliary functions:

- Reduce the number of emissions: By reducing engine speed, the mechanicaltransmission reduces the emissions emitted by the vehicle

- Increased fuel efficiency: Mechanical gearboxes can increase fuel efficiency

by adjusting torque to achieve better engine performance

- Increase engine life: Mechanical gearboxes can reduce the speed of the engineand help it operate at a lower productivity level, which extends the life of the motor

2.1.2.3 The relationship between revolutions, gear ratio and torque in mechanical gearboxes:

In mechanical gearboxes, there is a direct relationship between revolutions, gearratios and torque

The number of revolutions of the engine is measured in units of rpm (RPM), whiletorque is measured in Newton-meters (Nm) The gear ratio is calculated by dividing thenumber of revolutions of the shaft by the number of revolutions of the motor

The gear ratio is usually understood as the ratio between the revolution of theoutput shaft of the gearbox (output gear) and the rotation of the input shaft (motor) Asthe gear ratio increases, the number of revolutions of the engine decreases and the torqueincreases, and vice versa

Specifically, when the gear ratio is greater than 1, the motor will rotate more slowlythan the output shaft of the gearbox This leads to an increase in torque at the output gear

of the gearbox When the gear ratio is less than 1, the motor rotates faster than the output

shaft of the gearbox, which leads to a decrease in torque at the output gear of thegearbox

2.1.2.4 Impact of mechanical transmission on driving mode and vehicle performance:

The mechanical transmission has a great impact on the driving mode and performance ofthe car

In driving mode, the mechanical transmission allows the driver to adjust the speedand torque of the car by selecting different gear ratios When the car needs to increasespeed, the driver can switch to a higher gear level to achieve the desired speed.Conversely, when the car needs to slow down or face steep terrain, the driver can switch

to a lower gear level to increase torque and slow down

- In addition, the mechanical transmission also affects the performance of thecar When the vehicle uses the appropriate gear ratios, the vehicle's productivity and fuelefficiency are improved However, when the driver does not select the proper gear level

or uses too many gears, the engine can become overloaded and lead to increased fuelconsumption and reduced efficiency

- Moreover, the mechanical transmission also affects the smoothness andstability of the car When using the appropriate gear ratios, the car can move moresmoothly and stably Conversely, when the driver does not change gears properly orselects an inappropriate gear level, the car may shake or jerk sharply, reducing thestability of the vehicle

So, the proper use of a mechanical transmission will help improve the driving modeand performance of the car

* The impact of the gearbox on the driving mode and performance of the vehicle can be further detailed as follows:

+) Impact on driving mode:

- Speed control: The mechanical transmission allows the driver to adjust thespeed of the vehicle by selecting different gear ratios When the car needs to increasespeed, the driver can switch to a higher gear level to achieve the desired speed.Conversely, when the car needs to slow down or face steep terrain, the driver can switch

to a lower gear level to increase torque and slow down

- Torque control: The mechanical transmission also allows the driver to controlthe engine's torque by selecting the appropriate gear levels When the driver switches to

a higher gear level, the torque will decrease but the speed of the car will increase.Conversely, when switching to a lower gear, the torque will increase and the speed willdecrease

- Enhanced control: Mechanical transmissions can also give drivers bettercontrol over different road conditions, terrain, and traffic situations By shifting gearsappropriately, drivers can meet different requirements of the road, making the car gosmoother, minimizing collisions, and maintaining passenger and driver safety

+) Impact on vehicle performance:

- Increased productivity efficiency: With the use of appropriate gear ratios, thevehicle's productivity and fuel efficiency are improved This means that the engine willoperate more efficiently, consume less fuel and increase the vehicle's productivityefficiency

- Reduced fuel consumption: If the driver does not select the appropriate gearlevel or uses too many gears, the engine can be overloaded and result

2.1.2.5 Advantages and limitations of mechanical gearboxes:

+) Pros:

• Often more fuel efficient than automatic or CVT transmissions

• The price is cheaper than other types of gearboxes

• Maintenance is usually easier and less expensive

• Help the driver control the car better in many situations

• Having to use many operations to control the taper and reasonable gearhelps the driver concentrate more

• Bring a more realistic and interesting control feeling

+) Cons:

• Controlling and handling situations with a manual transmission is moredifficult than with an automatic car Besides, the "weak drivers" may feelstressed when they have to focus on observing the road, while having toperform quite a lot of operations of the manual transmission

• Causing inconvenience and discomfort in case of traffic jams, traffic jamsbecause the driver will have to regularly perform operations with the

gearbox, especially "taper clearing" to keep the car from shutting downwhen the road is crowded

2.1.3 New features and technologies in mechanical gearboxes:

2.1.3.1 Clutch systems and actuators in mechanical gearboxes:

In mechanical transmissions, clutch systems and transmissions are importantcomponents to drive power from the engine to the vehicle's powertrain

- The clutch system is used to disconnect or connect the engine to the gearbox.When the transmission is disconnected, the driver can shift gears or stop the car withouthaving to turn off the engine The clutch system consists of a clutch, a clutch disc and aclutch damper When the clutch is compressed, the clutch disc adheres to the gearbox fortransmission When the clutch is released, the clutch disc stops adhering to the gearboxand disconnects the engine from the gearbox

- The actuator consists of a system of gears, wand shaft and glass shaft Whenthe engine is running, it drives the gear system, which sets the car in motion The gears

in the transmission are designed to create different speed ratios, which help the car run atdifferent speeds The wand shaft and glass shaft help drive from the gearbox to thewheels

* Attention: The components in the clutch system and transmission all needperiodic maintenance and replacement to ensure the proper operation of the transmissionand vehicle

2.1.3.2 Mechanical gearbox and performance enhancing technology:

The mechanical transmission is an important part of a vehicle's powertrain and isresponsible for converting and adjusting torque from engine to wheels Traditionalmechanical transmissions often have quite limited gear ratios, low accuracy and manyother impacts on the performance of the car

In order to enhance the performance of mechanical transmissions, new technologiessuch as automatic transmissions, dual-clutch transmissions, sports transmissions and dualtransmissions are developed and widely used in the automotive industry at present The automatic transmission is designed to automatically shift gears to increaseefficiency and save fuel The dual-clutch transmission uses two clutch discs fortransmission, which increases load carrying capacity and reduces fuel consumption The

sports transmission can accelerate faster and provide a sportier driving experience Thedual transmission also uses two clutch discs but is capable of faster gear changes,increasing acceleration and reducing gear shift time

In addition, new technology such as electronic transmissions and dual automatictransmissions are used to reduce breakdowns and increase gearbox durability Thesetechnologies make the transmission smoother, more responsive and provide a betterdriving experience

=> In order to enhance the performance of mechanical gearboxes, new technologiessuch as automatic transmissions, dual-clutch transmissions, sports transmissions and dualtransmissions are widely used in the automotive industry at present These newtechnologies increase load capacity, reduce fuel consumption and provide a betterdriving experience

2.1.3.3 Automatic and semi-automatic gear shift systems:

Automatic (AT) and semi-automatic (AMT) gear shifting systems are twoadvanced gear shifting technologies widely used in cars today Both of thesetechnologies enhance performance and utility while driving

The automatic gear shift system is a fully automatic gear shift system, which doesnot need to be manually manipulated This system uses sensors to determine speed andcontrol gear shifts When the vehicle's speed increases or decreases, the AT systemautomatically adjusts the amount of lubricant and shifts gears to ensure the vehicleperforms at its best AT systems are commonly used in high-end vehicles and sports cars

A semi-automatic system is an automatic gear shift system controlled by anelectronic control unit The driver can shift gears using the buttons or steering wheel.AMT systems are commonly used in trucks and buses

Both of these technologies have their own advantages The AT system makesdriving easier and more fuel-efficient in urban conditions and traffic jams Meanwhile,the AMT system can shift gears faster and provide greater customization for the driver However, both of these technologies also have disadvantages The AT system maycost more than a manual gear shift system and may not perform gear shifts exactly as thedriver desires Meanwhile, the AMT system may not perform smooth gear shifts and

=> Automatic and semi-automatic gear shifting systems are two advanced gearshifting technologies widely used in cars today Each technology has its own advantagesand disadvantages, depending on the conditions of use and the preferences of the driver

2.1.3.4 Advanced technologies in mechanical gearboxes:

Advanced technologies in mechanical gearboxes include:

- 6-speed transmission: A 6-speed transmission allows the car to run at higherspeeds and is more fuel efficient than a 5-speed transmission Automakers are activelyresearching and using 7- or 8-speed gearboxes to further improve performance and fueleconomy

- Dual transmission: The dual transmission allows the car to switch betweentwo different transmissions This gearbox also enhances performance and is more fuelefficient than the basic gearbox

- Stepless gearbox: Stepless gearboxes use a chain system to control movement.This system enhances efficiency and fuel economy compared to the basic gearbox

- Semi-stepless gearbox: Semi-stepless gearboxes use a stepless system andseveral basic gearboxes to create gear levels This system enhances efficiency and fueleconomy compared to the basic gearbox

- Robot gearbox: A robot gearbox is a type of mechanical gearbox controlled

by an electronic control unit This type of gearbox allows for faster and smoother gearchanges than the basic gearbox

- Dual automatic transmission: Dual automatic transmissions use two tapers tocontrol movement This type of transmission enhances performance and is more fuelefficient than the basic automatic transmission

=> The advanced technologies in mechanical gearboxes are all aimed at enhancingthe performance and fuel economy of the car Each type of gearbox has its ownadvantages and disadvantages, depending on the conditions of use and the preferences ofthe driver

2.1.4 Developments and trends in mechanical transmissions in cars:

2.1.4.1 Improved performance and fuel efficiency in mechanical gearboxes:

There are many improvements to improve efficiency and fuel efficiency inmechanical gearboxes Here are some common improvements:

- Increased gear levels: A simple way to improve fuel efficiency and reduceengine operating at low revs is to increase gear exponentially Modern mechanicaltransmissions can have up to 7 or 8 gear speeds, which allows the engine to operate atlower rpm, reducing fuel consumption and engine noise

- Use clutch split system: The clutch split system reduces the wear of parts inthe mechanical gearbox, increases the service life of the gearbox and reduces repaircosts In addition, the clutch split system reduces traction between the engine andgearbox, improving fuel efficiency

- Use good grease: Using good grease can help reduce friction, improveperformance and reduce fuel consumption in mechanical gearboxes

- Use of advanced technologies: Advanced technologies such as autopilot modeand Electronic Limited Slip Differential can help increase the performance ofmechanical gearboxes and improve fuel efficiency and efficiency

- Optimal gearbox design: Optimal gearbox design with lightweight, high-loadcomponents and good heat dissipation can help improve performance and reduce fuelconsumption of mechanical gearboxes

2.1.4.2 Integration of intelligent and connected technologies in mechanical gearboxes:

Currently, with the development of technology, mechanical gearboxes are alsointegrated with smart and connected technologies to improve operating efficiency andfuel economy Here are some examples:

Smart Transmission: Smart transmissions use sensors to measure fuel volume,speed and road conditions From there, the gearbox will automatically adjust the speedand gear to save fuel

Automatic Transmission: Automatic transmissions are integrated with connectedtechnologies to optimize gear shifting, acceleration and reduce engine operation at lowerrpm, helping to save fuel and improve performance

GPS-linked transmission: GPS-linked transmissions use positioning information todetermine the slope and curvature of the road ahead From there, the gearbox willautomatically adjust gears to reduce fuel consumption and increase efficiency

transmission and performance indicators, helping the driver adjust the driving style andfuel economy

Transmission-Connected Telematics System: Mechanical transmissions are linked

to the cruise monitoring system to provide information about engine speed, positioningand operation From there, the cruise monitoring system automatically adjusts thegearbox to save fuel and improve performance

2.1.4.3 Direction of mechanical gearbox technology in the future:

In the future, mechanical gearbox technology will continue to evolve and beintegrated with other advanced technologies to improve performance, increase safety andreduce environmental impact Some directions of future mechanical gearbox technologyinclude:

Fully Automatic Transmission: A fully automatic transmission will not require ahuman operator, but will be controlled by an intelligent electronic system This will helpincrease safety and reduce human error

Using Super-Lightweight and Super-Strong Materials: Using ultra-light and strong materials such as carbon fiber, aluminum, titanium to reduce gearbox weightand increase operational efficiency, while reducing emissions and environmental impact Integrated Engine Stability Technology: This technology will help adjust engineoperation to optimize performance and fuel economy, while reducing operating noise andvibration

super-Electric Transmission: super-Electric transmissions use electric motors to replacetraditional internal combustion engines This will reduce emissions and noise, whileincreasing performance and functionality

Electronic Automatic Transmission: The electronic automatic transmission will beintegrated with sensors and controllers to automatically adjust the gear to suit the speedand road conditions, helping to optimize performance and fuel economy

2.2 Force to choose the design plan and design the calculation of the gearbox

2.2.1 Selection of design plan

Based on the classification of conventional mechanical gearboxes by number ofaxles, there are two options:

- 3-axis gearbox

- 2-axis gearbox

The subject topic I chose was "Design of a 5-seater mechanical transmission",reference parameters for Vios 2016 assembled in Vietnam Vios 2016 has a front-engine,active front-wheel drive Based on the analysis of advantages and disadvantages of 2-axis and 3-axis gearboxes, I choose 2-axis gearboxes

The 2-axle gearbox can be arranged with 4, 5 or more gear speeds The greater thenumber of gear levels, the better the use of engine power, higher fuel economy.However, the manual control gearbox, gearbox structure, gear shift control unit arecomplicated So choose a 5-speed transmission transmission for cars

Based on the design requirements of the problem and according to the referencecar, we choose a 2-axle 5-gear forward gearbox:

Form 2.3: 5-speed 2-axis gearbox diagram

Table 2.1: The working state of the gearbox

2.2.2 Gearbox calculation design

Based on some parameters according to the reference car Vios 1.5E (MT)

Table 2.2: Calculation data sheet

2.2.2.1 Calculation of the gear ratio

a Determine the gear ratio of the main power transmission (i0)

Gear ratio of main power transmission 𝑖* determined from guaranteed conditionsfor cars

reaches the maximum velocity, determined by the formula: