Automotive Power Transmission Systems (Automotive Series)

Provides technical details and developments for all automotive power transmission systems The transmission system of an automotive vehicle is the key to the dynamic performance, drivability and comfort, and fuel economy. Modern advanced transmission systems are the combination of mechanical, electrical and electronic subsystems. The development of transmission products requires the synergy of multi-disciplinary expertise in mechanical engineering, electrical engineering, and electronic and software engineering. Automotive Power Transmission Systems comprehensively covers various types of power transmission systems of ground vehicles, including conventional automobiles driven by internal combustion engines, and electric and hybrid vehicles. The book covers the technical aspects of design, analysis and control for manual transmissions, automatic transmission, CVTs, dual clutch transmissions, electric drives, and hybrid power systems. It not only presents the technical details of key transmission components, but also covers the system integration for dynamic analysis and control. Key features: Covers conventional automobiles as well as electric and hybrid vehicles. Covers aspects of design, analysis and control. Includes the most recent developments in the field of automotive power transmission systems. The book is essential reading for researchers and practitioners in automotive, mechanical and electrical engineering. Title Page......Page 5 Copyright Page......Page 6 Contents......Page 7 Series Preface......Page 13 Preface......Page 15 1.1 Introduction......Page 19 1.2.1 Engine Output Power and Torque......Page 20 1.2.2 Engine Fuel Map......Page 22 1.2.3 Engine Emission Map......Page 23 1.3 Road Load, Driving Force, and Acceleration......Page 24 1.3.1 Axle Loads......Page 25 1.3.2 Road Loads......Page 26 1.3.3 Powertrain Kinematics and Traction......Page 27 1.3.4 Driving Condition Diagram......Page 31 1.3.5 Ideal Transmission......Page 33 1.3.6 Power–Speed Chart......Page 35 1.4.1 Highest Gear Ratio......Page 36 1.4.2 First Gear Ratio......Page 37 1.4.3 Intermediate Gear Ratios......Page 38 1.4.4 Finalization of Gear Ratios......Page 41 Problem......Page 44 2.1 Introduction......Page 47 2.2 Powertrain Layout and Manual Transmission Structure......Page 48 2.3 Power Flows and Gear Ratios......Page 55 2.4.1 Clutch Structure......Page 58 2.4.2 Clutch Torque Capacity......Page 61 2.4.3 Clutch Design......Page 62 2.5.1 Shift without Synchronizer......Page 63 2.5.2 Shift with Synchronizer......Page 65 2.6 Dynamic Modeling of Synchronization Process......Page 70 2.6.1 Equivalent Mass Moment of Inertia......Page 71 2.6.2 Equation of Motion during Synchronization......Page 73 2.6.3 Condition for Synchronization......Page 74 2.7 Shifting Mechanisms......Page 77 Problems......Page 80 3.1 Introduction......Page 83 3.2.1 Conjugate Motion and Definitions......Page 84 3.2.2 Property of Involute Curves......Page 85 3.2.3 Involute Curves as Gear Tooth Profiles......Page 86 3.2.4 Characteristics of Involute Gearing......Page 87 3.3.2 Standardization of Tooth Dimensions......Page 90 3.3.4 Contact Ratio......Page 92 3.3.5 Tooth Thickness and Space along the Tooth Height......Page 94 3.4.1 Standard and Non-Standard Cutter Settings......Page 96 3.4.2 Avoidance of Tooth Undercutting and Minimum Number of Teeth......Page 97 3.4.3 Systems of Non-standard Gears......Page 99 3.4.5 Design of General Non-Standard Gear System......Page 101 3.5 Involute Helical Gears......Page 104 3.5.2 Design Parameters on the Normal and Transverse Sections......Page 105 3.5.4 Minimum Number of Teeth for Involute Helical Gears......Page 107 3.5.5 Contact Ratio of Involute Helical Gears......Page 108 3.6.1 Determination of Gear Forces......Page 109 3.6.3 Pitting Resistance......Page 111 3.6.4 Bending Strength......Page 112 3.7 Design of Automotive Transmission Gears......Page 113 3.8 Planetary Gear Trains......Page 121 3.8.1 Simple Planetary Gear Train......Page 124 3.8.3 Ravigneaux Planetary Gear Train......Page 125 References......Page 126 Problems......Page 127 4.1 Introduction......Page 129 4.2 Torque Converter Structure and Functions......Page 130 4.2.1 Torque Multiplication and Fluid Coupling......Page 132 4.2.2 Torque Converter Locking up......Page 133 4.3.1 Terminologies and Definitions......Page 134 4.3.2 Velocity Diagrams......Page 137 4.3.3 Angular Momentum of ATF Flow and Torque Formulation......Page 140 4.4 Torque Capacity and Input–Output Characteristics......Page 142 4.4.1 Torque Converter Capacity Factor......Page 143 4.4.2 Input–Output Characteristics......Page 145 4.4.3 Joint Operation of Torque Converter and Engine......Page 146 4.4.4 Joint Operation of Torque Converter and Vehicle Powertrain......Page 147 References......Page 151 Problem......Page 152 5.1 Introduction......Page 155 5.2 Structure of Automatic Transmissions......Page 157 5.3.1 Ford FWD Six-Speed AT......Page 171 5.3.2 Ford six-speed RWD Ravigneaux AT......Page 178 5.3.3 ZF RWD Eight-Speed AT......Page 180 5.4 Transmission Dynamics......Page 182 5.4.1 Ford FWD Six-Speed AT......Page 183 5.4.2 Ford RWD Six-Speed AT......Page 188 5.4.3 ZF RWD Eight-Speed AT......Page 190 5.5 Qualitative Analysis on Transmission Shifting Dynamics......Page 193 5.6 General Vehicle Powertrain Dynamics......Page 204 5.6.1 General State Variable Equation in Matrix Form......Page 205 5.6.2 Specific State Variable Equation......Page 206 5.6.3 Solution of State Variables by Variable Substitution......Page 210 5.6.4 Vehicle System Integration......Page 211 5.7 Simulation of Vehicle Powertrain Dynamics......Page 213 Problems......Page 216 6.1 Introduction......Page 219 6.2 Components and Hydraulic Circuits for Transmission Control......Page 221 6.3.1 System Hydraulic Circuitry for the Previous Generation of ATs......Page 234 6.3.2 System Hydraulic Circuitry for ATs with Independent Clutch Pressure Control......Page 236 6.3.3 System Hydraulic Circuitry for ATs with Direct Clutch Pressure Control......Page 241 6.4.1 Transmission shift schedule......Page 243 6.4.2 Torque Converter Lock Control......Page 246 6.4.3 Lock-Release Schedule......Page 247 6.4.4 Lock-Release Operation......Page 249 6.4.5 Engine Torque Control During Shifts......Page 251 6.4.6 Shift Process Control......Page 254 6.4.7 Initial Clutch Pressure Profiles......Page 256 6.4.9 Feedback Shift Control......Page 257 6.4.10 Torque Based Shift Control......Page 259 6.5 Calibration of Transmission Control System......Page 263 6.5.1 Component Level Calibration......Page 264 6.5.2 System Level Calibration......Page 265 References......Page 267 Problem......Page 268 7.1 Introduction......Page 269 7.2 CVT Layouts and Key Components......Page 271 7.2.2 Input and Output Pulleys......Page 272 7.2.3 Basic Ratio Equation......Page 273 7.3.1 Forces Acting on a Metal Block......Page 275 7.3.2 Forces Acting on Pulley Sheaves......Page 276 7.3.3 Block Compression and Ring Tension......Page 280 7.3.4 Torque Transmitting Mechanism......Page 281 7.3.5 Forces Acting on the Whole Belt......Page 285 7.3.6 Relation between Thrusts on Input and Output Pulleys......Page 286 7.3.7 Ratio Changing Mechanism......Page 290 7.4 CVT Control System Design and Operation Control......Page 291 7.4.1 VBS Based Control System......Page 292 7.4.2 Servo Mechanism Control System......Page 295 7.4.3 Comparison of the Two Control System Designs......Page 303 7.5.1 Line Pressure Control......Page 305 7.5.2 Continuous Ratio Control Strategy......Page 306 7.5.3 Stepped Ratio Control Strategy......Page 310 7.5.4 CVT Control Calibration......Page 311 References......Page 313 Problems......Page 314 8.1 Introduction......Page 317 8.2 DCT Layouts and Key Components......Page 318 8.2.1 Dry Dual Clutch Transmissions......Page 319 8.2.2 Wet Dual Clutch Transmissions......Page 324 8.3.1 Equations of Motion during Launch and Shifts......Page 325 8.4 DCT Clutch Control......Page 331 8.5.1 Correlation on Clutch Torque and Control Variable......Page 340 8.5.2 Case Study on Clutch Torque and Control Variable Correlation......Page 343 8.5.3 Algorithm for Clutch Torque Calculation under Real Time Conditions......Page 345 8.5.4 Case Study for the Clutch Torque Algorithm......Page 346 References......Page 348 Problems......Page 349 9.2 Current Status and Trends for EVs......Page 351 9.3 Output Characteristic of Electric Machines......Page 354 9.4 DC Machines......Page 355 9.4.1 Principle of DC Machines......Page 356 9.4.2 Excitation Types of DC Machines......Page 360 9.4.3 Speed Control of DC Machines......Page 361 9.5 Induction Machines......Page 365 9.5.1 Principle of Induction Motors......Page 366 9.5.2 Equivalent Circuit of Induction Motors......Page 367 9.5.3 Speed Control of Induction Machine......Page 370 9.5.4 Variable Frequency, Variable Voltage Control of Induction Motors......Page 372 9.5.5 Efficiency and Losses of Induction Machine......Page 373 9.5.6 Field-Oriented Control of Induction Machine......Page 374 9.6.1 Basic Configuration of PM Motors......Page 379 9.6.2 Basic Principle and Operation of PM Motors......Page 382 9.7 Switched Reluctance Motors......Page 388 9.8.1 Single-Speed EV Transmission......Page 390 9.8.2 Multiple Ratio EV Transmissions......Page 392 9.9 Conclusions......Page 397 Bibliography......Page 398 Chapter 10 Hybrid Powertrains......Page 407 10.1 Series HEVs......Page 408 10.2 Parallel HEVs......Page 409 10.3 Series–Parallel HEVs......Page 412 10.4.1 GM Two-Mode Hybrid Transmission......Page 418 10.4.2 Dual Clutch Hybrid Transmissions......Page 425 10.4.3 Hybrid Transmission Proposed by Zhang, et al.......Page 431 10.4.4 Renault IVT Hybrid Transmission......Page 433 10.4.5 Timken Two-Mode Hybrid Transmission......Page 434 10.4.6 Tsai’s Hybrid Transmission......Page 437 10.4.7 Hybrid Transmission with Both Speed and Torque Coupling Mechanism......Page 439 10.4.8 Toyota Highlander and Lexus Hybrid, e-Four Wheel Drive......Page 441 10.4.9 CAMRY Hybrid......Page 442 10.4.10 Chevy Volt Powertrain......Page 443 10.6 Dynamics of Planetary Gear Based Transmissions......Page 445 10.7 Conclusions......Page 446 References......Page 447 Index......Page 449 EULA......Page 455 Title Page 5 Copyright Page 6 Contents 7 Series Preface 13 Preface 15 Chapter 1 Automotive Engine Matching 19 1.1 Introduction 19 1.2 Output Characteristics of Internal Combustion Engines 20 1.2.1 Engine Output Power and Torque 20 1.2.2 Engine Fuel Map 22 1.2.3 Engine Emission Map 23 1.3 Road Load, Driving Force, and Acceleration 24 1.3.1 Axle Loads 25 1.3.2 Road Loads 26 1.3.3 Powertrain Kinematics and Traction 27 1.3.4 Driving Condition Diagram 31 1.3.5 Ideal Transmission 33 1.3.6 Power–Speed Chart 35 1.4 Selection of Gear Ratios 36 1.4.1 Highest Gear Ratio 36 1.4.2 First Gear Ratio 37 1.4.3 Intermediate Gear Ratios 38 1.4.4 Finalization of Gear Ratios 41 References 44 Problem 44 Chapter 2 Manual Transmissions 47 2.1 Introduction 47 2.2 Powertrain Layout and Manual Transmission Structure 48 2.3 Power Flows and Gear Ratios 55 2.4 Manual Transmission Clutches 58 2.4.1 Clutch Structure 58 2.4.2 Clutch Torque Capacity 61 2.4.3 Clutch Design 62 2.5 Synchronizer and Synchronization 63 2.5.1 Shift without Synchronizer 63 2.5.2 Shift with Synchronizer 65 2.6 Dynamic Modeling of Synchronization Process 70 2.6.1 Equivalent Mass Moment of Inertia 71 2.6.2 Equation of Motion during Synchronization 73 2.6.3 Condition for Synchronization 74 2.7 Shifting Mechanisms 77 References 80 Problems 80 Chapter 3 Transmission Gear Design 83 3.1 Introduction 83 3.2 Gear Design Fundamentals 84 3.2.1 Conjugate Motion and Definitions 84 3.2.2 Property of Involute Curves 85 3.2.3 Involute Curves as Gear Tooth Profiles 86 3.2.4 Characteristics of Involute Gearing 87 3.3 Design of Tooth Element Proportions of Standard Gears 90 3.3.1 Gear Dimensional and Geometrical Parameters 90 3.3.2 Standardization of Tooth Dimensions 90 3.3.3 Tooth Dimensions of Standard Gears 92 3.3.4 Contact Ratio 92 3.3.5 Tooth Thickness and Space along the Tooth Height 94 3.4 Design of Non-Standard Gears 96 3.4.1 Standard and Non-Standard Cutter Settings 96 3.4.2 Avoidance of Tooth Undercutting and Minimum Number of Teeth 97 3.4.3 Systems of Non-standard Gears 99 3.4.5 Design of General Non-Standard Gear System 101 3.5 Involute Helical Gears 104 3.5.1 Characteristics of Involute Helical Gearing 105 3.5.2 Design Parameters on the Normal and Transverse Sections 105 3.5.3 Tooth Dimensions of Standard Involute Helical Gears 107 3.5.4 Minimum Number of Teeth for Involute Helical Gears 107 3.5.5 Contact Ratio of Involute Helical Gears 108 3.5.6 Design of Non-standard Involute Helical Gears 109 3.6 Gear Tooth Strength and Pitting Resistance 109 3.6.1 Determination of Gear Forces 109 3.6.2 AGMA Standard on Bending Strength and Pitting Resistance 111 3.6.3 Pitting Resistance 111 3.6.4 Bending Strength 112 3.7 Design of Automotive Transmission Gears 113 3.8 Planetary Gear Trains 121 3.8.1 Simple Planetary Gear Train 124 3.8.2 Dual-Planet Planetary Gear Train 125 3.8.3 Ravigneaux Planetary Gear Train 125 References 126 Problems 127 Chapter 4 Torque Converters 129 4.1 Introduction 129 4.2 Torque Converter Structure and Functions 130 4.2.1 Torque Multiplication and Fluid Coupling 132 4.2.2 Torque Converter Locking up 133 4.3 ATF Circulation and Torque Formulation 134 4.3.1 Terminologies and Definitions 134 4.3.2 Velocity Diagrams 137 4.3.3 Angular Momentum of ATF Flow and Torque Formulation 140 4.4 Torque Capacity and Input–Output Characteristics 142 4.4.1 Torque Converter Capacity Factor 143 4.4.2 Input–Output Characteristics 145 4.4.3 Joint Operation of Torque Converter and Engine 146 4.4.4 Joint Operation of Torque Converter and Vehicle Powertrain 147 References 151 Problem 152 Chapter 5 Automatic Transmissions 155 5.1 Introduction 155 5.2 Structure of Automatic Transmissions 157 5.3 Ratio Analysis and Synthesis 171 5.3.1 Ford FWD Six-Speed AT 171 5.3.2 Ford six-speed RWD Ravigneaux AT 178 5.3.3 ZF RWD Eight-Speed AT 180 5.4 Transmission Dynamics 182 5.4.1 Ford FWD Six-Speed AT 183 5.4.2 Ford RWD Six-Speed AT 188 5.4.3 ZF RWD Eight-Speed AT 190 5.5 Qualitative Analysis on Transmission Shifting Dynamics 193 5.6 General Vehicle Powertrain Dynamics 204 5.6.1 General State Variable Equation in Matrix Form 205 5.6.2 Specific State Variable Equation 206 5.6.3 Solution of State Variables by Variable Substitution 210 5.6.4 Vehicle System Integration 211 5.7 Simulation of Vehicle Powertrain Dynamics 213 References 216 Problems 216 Chapter 6 Automatic Transmissions 219 6.1 Introduction 219 6.2 Components and Hydraulic Circuits for Transmission Control 221 6.3 System Circuit Configurations for Transmission Control 234 6.3.1 System Hydraulic Circuitry for the Previous Generation of ATs 234 6.3.2 System Hydraulic Circuitry for ATs with Independent Clutch Pressure Control 236 6.3.3 System Hydraulic Circuitry for ATs with Direct Clutch Pressure Control 241 6.4 Transmission Control Strategy 243 6.4.1 Transmission shift schedule 243 6.4.2 Torque Converter Lock Control 246 6.4.3 Lock-Release Schedule 247 6.4.4 Lock-Release Operation 249 6.4.5 Engine Torque Control During Shifts 251 6.4.6 Shift Process Control 254 6.4.7 Initial Clutch Pressure Profiles 256 6.4.8 Initial Piston Stroke Attributes 257 6.4.9 Feedback Shift Control 257 6.4.10 Torque Based Shift Control 259 6.4.11 System Diagnosis and Failure Mode Management 263 6.5 Calibration of Transmission Control System 263 6.5.1 Component Level Calibration 264 6.5.2 System Level Calibration 265 References 267 Problem 268 Chapter 7 Continuously Variable Transmissions 269 7.1 Introduction 269 7.2 CVT Layouts and Key Components 271 7.2.1 Belt Structure 272 7.2.2 Input and Output Pulleys 272 7.2.3 Basic Ratio Equation 273 7.3 Force Analysis for Belt CVT 275 7.3.1 Forces Acting on a Metal Block 275 7.3.2 Forces Acting on Pulley Sheaves 276 7.3.3 Block Compression and Ring Tension 280 7.3.4 Torque Transmitting Mechanism 281 7.3.5 Forces Acting on the Whole Belt 285 7.3.6 Relation between Thrusts on Input and Output Pulleys 286 7.3.7 Ratio Changing Mechanism 290 7.4 CVT Control System Design and Operation Control 291 7.4.1 VBS Based Control System 292 7.4.2 Servo Mechanism Control System 295 7.4.3 Comparison of the Two Control System Designs 303 7.5 CVT Control Strategy and Calibration 305 7.5.1 Line Pressure Control 305 7.5.2 Continuous Ratio Control Strategy 306 7.5.3 Stepped Ratio Control Strategy 310 7.5.4 CVT Control Calibration 311 References 313 Problems 314 Chapter 8 Dual Clutch Transmissions 317 8.1 Introduction 317 8.2 DCT Layouts and Key Components 318 8.2.1 Dry Dual Clutch Transmissions 319 8.2.2 Wet Dual Clutch Transmissions 324 8.3 Modeling of DCT Vehicle Dynamics 325 8.3.1 Equations of Motion during Launch and Shifts 325 8.4 DCT Clutch Control 331 8.5 Clutch Torque Formulation 340 8.5.1 Correlation on Clutch Torque and Control Variable 340 8.5.2 Case Study on Clutch Torque and Control Variable Correlation 343 8.5.3 Algorithm for Clutch Torque Calculation under Real Time Conditions 345 8.5.4 Case Study for the Clutch Torque Algorithm 346 References 348 Problems 349 Chapter 9 Electric Powertrains 351 9.1 Basics of Electric Vehicles 351 9.2 Current Status and Trends for EVs 351 9.3 Output Characteristic of Electric Machines 354 9.4 DC Machines 355 9.4.1 Principle of DC Machines 356 9.4.2 Excitation Types of DC Machines 360 9.4.3 Speed Control of DC Machines 361 9.5 Induction Machines 365 9.5.1 Principle of Induction Motors 366 9.5.2 Equivalent Circuit of Induction Motors 367 9.5.3 Speed Control of Induction Machine 370 9.5.4 Variable Frequency, Variable Voltage Control of Induction Motors 372 9.5.5 Efficiency and Losses of Induction Machine 373 9.5.6 Field-Oriented Control of Induction Machine 374 9.6 Permanent Magnet Motor Drives 379 9.6.1 Basic Configuration of PM Motors 379 9.6.2 Basic Principle and Operation of PM Motors 382 9.7 Switched Reluctance Motors 388 9.8 EV Transmissions 390 9.8.1 Single-Speed EV Transmission 390 9.8.2 Multiple Ratio EV Transmissions 392 9.9 Conclusions 397 Bibliography 398 Chapter 10 Hybrid Powertrains 407 10.1 Series HEVs 408 10.2 Parallel HEVs 409 10.3 Series–Parallel HEVs 412 10.4 Complex HEVs 418 10.4.1 GM Two-Mode Hybrid Transmission 418 10.4.2 Dual Clutch Hybrid Transmissions 425 10.4.3 Hybrid Transmission Proposed by Zhang, et al. 431 10.4.4 Renault IVT Hybrid Transmission 433 10.4.5 Timken Two-Mode Hybrid Transmission 434 10.4.6 Tsai’s Hybrid Transmission 437 10.4.7 Hybrid Transmission with Both Speed and Torque Coupling Mechanism 439 10.4.8 Toyota Highlander and Lexus Hybrid, e-Four Wheel Drive 441 10.4.9 CAMRY Hybrid 442 10.4.10 Chevy Volt Powertrain 443 10.5 Non-Ideal Gears in the Planetary System 445 10.6 Dynamics of Planetary Gear Based Transmissions 445 10.7 Conclusions 446 References 447 Index 449 EULA 455

Provides technical details and developments for all automotive power transmission systems

The transmission system of an automotive vehicle is the key to the dynamic performance, drivability and comfort, and fuel economy. Modern advanced transmission systems are the combination of mechanical, electrical and electronic subsystems. The development of transmission products requires the synergy of multi-disciplinary expertise in mechanical engineering, electrical engineering, and electronic and software engineering.

Automotive Power Transmission Systems comprehensively covers various types of power transmission systems of ground vehicles, including conventional automobiles driven by internal combustion engines, and electric and hybrid vehicles. The book covers the technical aspects of design, analysis and control for manual transmissions, automatic transmission, CVTs, dual clutch transmissions, electric drives, and hybrid power systems. It not only presents the technical details of key transmission components, but also covers the system integration for dynamic analysis and control.

Key features:

• Covers conventional automobiles as well as electric and hybrid vehicles.
• Covers aspects of design, analysis and control.
• Includes the most recent developments in the field of automotive power transmission systems.

The book is essential reading for researchers and practitioners in automotive, mechanical and electrical engineering.

**__Provides technical details and developments for all automotive power transmission systems__**The transmission system of an automotive vehicle is the key to the dynamic performance, drivability and comfort, and fuel economy. Modern advanced transmission systems are the combination of mechanical, electrical and electronic subsystems. The development of transmission products requires the synergy of multi-disciplinary expertise in mechanical engineering, electrical engineering, and electronic and software engineering.__Automotive Power Transmission Systems__Key features:Covers conventional automobiles as well as electric and hybrid vehicles. Covers aspects of design, analysis and control. Includes the most recent developments in the field of automotive power transmission systems.The book is essential reading for researchers and practitioners in automotive, mechanical and electrical engineering. This volume provides a solid foundation forlogical gear design practices and data. Topics include an analysis of conjugate gear-tooth action, nature of the contact, and resulting gear-tooth profiles of several types of gears, plus gear teeth in action. Indispensable guide for engineers concerned with tooth geometry, manufacturing accuracies,and general design. 1949 edition.