Automotive Series
Series Editor: Thomas Kurfess
Automotive Power Transmission Systems | Zhang and Mi | September 2018 |
Hybrid Electric Vehicles: Principles and | Mi and Masrur | October 2017 |
Applications with Practical Perspectives, 2nd Edition | ||
Hybrid Electric Vehicle System Modeling and Control, 2nd Edition | Liu | April 2017 |
Thermal Management of Electric Vehicle Battery Systems | Dincer, Hamut and Javani | March 2017 |
Automotive Aerodynamics | Katz | April 2016 |
The Global Automotive Industry | Nieuwenhuis and Wells | September 2015 |
Vehicle Dynamics | Meywerk | May 2015 |
Vehicle Gearbox Noise and Vibration: Measurement, Signal Analysis, Signal Processing and Noise Reduction Measures | Tůma | April 2014 |
Modeling and Control of Engines and Drivelines | Eriksson and Nielsen | April 2014 |
Modelling, Simulation and Control of Two‐Wheeled Vehicles | Tanelli, Corno and Savaresi | March 2014 |
Advanced Composite Materials for | Elmarakbi | December 2013 |
Automotive Applications: Structural Integrity and Crashworthiness | ||
Guide to Load Analysis for Durability in Vehicle Engineering | Johannesson and Speckert | November 2013 |
This edition first published 2018
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Library of Congress Cataloging-in-Publication Data
Names: Zhang, Yi, 1962 September 1- author. | Mi, Chris, author.
Title: Automotive power transmission systems / by Yi Zhang, Chris Mi.
Description: Hoboken, NJ : John Wiley & Sons, 2018. | Includes bibliographical references and index. |
Identifiers: LCCN 2018013178 (print) | LCCN 2018028719 (ebook) | ISBN 9781118964910 (pdf) | ISBN 9781118964903 (epub) | ISBN 9781118964811 (cloth)
Subjects: LCSH: Automobiles‒Transmission devices.
Classification: LCC TL262 (ebook) | LCC TL262 .Z43 2018 (print) | DDC 629.2/44‒dc23
LC record available at https://lccn.loc.gov/2018013178
Cover design by Wiley
Cover images: Background: © solarseven/Shutterstock; Left: Courtesy of Yi Zhang and Chris Mi; Middle: © Dong liu/Shutterstock; Right: © Scharfsinn86/Getty Images
Automotive power transmission systems are critical elements of any automobile. The ability to transmit power from the engine of a vehicle to the rest of the drive train is of primary importance. Furthermore, the design of power transmission systems is of critical importance to the overall vehicle system performance, as it affects not only performance characteristics such as torque and acceleration, but it also directly affects fuel efficiency and emissions. The power transmission system also presents one of the most complex design tasks in the overall automotive systems design and integration because it must interface with a variety of power plants such as internal combustion, electric, and hybrid plants. This is further complicated by the fact that engineers must consider a variety of transmission designs such as manual, automatic, and continuously variable systems. Furthermore, all of these elements must be condensed into the smallest, lightest package possible while functioning under significant loads over long periods of time.
Automotive Power Transmission Systems presents a thorough discussion of the various concepts that must be considered when designing a power transmission system. The book begins with an excellent discussion of how a transmission is designed by matching the engine output and the vehicle performance via proper transmission ratio selection. It then proceeds to discuss the basics of manual transmission and the analysis and design of essential transmission subsystems and components such as the gears, torque converter, and clutches. The authors then discuss more advanced transmission types such as dual clutch transmissions, continuously variable transmissions and automatic transmissions. In the final chapters, advanced control concepts for transmissions are presented, leading to the final chapters on electric and hybrid powertrains. This powerful combination of concepts results in a text that has both breadth and depth that will be valued as both a classroom text and a reference book.
The authors of Automotive Power Transmission Systems have done an excellent job in providing a thorough technical foundation for vehicle power transmission analysis and control. The text includes a number of clearly presented examples that are of significant use to the practicing engineer, resulting in a book that is an excellent blend of practical applications and fundamental concepts. The strength of this text is that it links a number of fundamental concepts to very pragmatic examples, providing the reader with significant insights into modern automotive power transmission technology. The authors have done a wonderful job in clearly and concisely bringing together the significant breadth of technologies necessary to successfully implement a modern power transmission system, providing a fundamentally grounded book that thoroughly explains power transmissions. It is well written, and is authored by recognized experts in a field that is critical to the automotive sector. It provides an excellent set of pragmatic and fundamental perspectives to the reader and is an excellent addition to the Automotive series.
Automotive power transmission systems deliver output from the power source, which can be an internal combustion engine or an electric motor or a combination of them, to the driving wheels. There are many valuable books and monographs published for internal combustion engines (ICE), but only a few can be found in the public domain, as referenced in this book, that are specifically written for automotive transmissions. Technical publications by the Society of Automotive Engineers (SAE) in transmissions are mostly for conventional ICE vehicles and are basically collections of research papers that are aimed at readers with high expertise in transmission sub‐areas. The purpose of this book is to offer interested readers, including undergraduate or graduate students and practicing engineers in the related disciplines, a systematic coverage of the design, analysis, and control of various types of automotive transmissions for conventional ICE vehicles, pure electric vehicles, and hybrid vehicles. The aim is that this book can be used either as a textbook for students in the field of vehicular engineering or as a reference book for engineers working in the automotive industry.
The authors have taught a series of courses on powertrain systems for both ICE and electric‐hybrid vehicles over many years in the graduate programs of mechanical engineering, electrical engineering, and automotive systems engineering at the University of Michigan‐Dearborn. The lecture notes of these courses form the framework for the book chapters, the main topics of which are highlighted below.
The book starts with automotive engine matching in Chapter 1, which covers the following technical topics: output characteristics of internal combustion engines, vehicle road loads and acceleration, driving force (or traction) and power requirements, vehicle performance dynamics and fuel economy, and transmission ratio selection for fuel economy and performance. The formulation and related analysis in Chapter 1 on road loads, performance dynamics, and powertrain kinematics are applicable to all vehicles driven by wheels and will be used throughout the book.
Chapter 2 covers manual transmissions, focusing on gear layouts, clutch design, synchronizer design, and synchronization analysis. Detailed analysis is provided on the operation principles of synchronizers and on the synchronization process during gear shifts. Example production transmissions are used as case studies to demonstrate principles and approaches that are then generally applicable.
For readers’ convenience, Chapter 3 provides the basics of the theory of gearing and gear design with specific application to manual transmissions (MT). With example transmissions, the chapter details geometry design, gear load calculation, and gear strength and power ratings for standard and non‐standard gears using existing equations or formulae from AGMA standards. The chapter also includes a separate section on the kinematics of planetary gear trains which are widely applied in automatic transmissions (AT). Readers are strongly recommended to read this section before reading Chapters 5 and 6.
Chapter 4 covers the structure, design, and characteristics of torque converters, focusing on torque converter operation principles, functionalities, and input–output characteristics. Methods for the determination of engine–converter joint operation states are presented in detail. The chapter also deals with the modeling of the combined operation of the entire vehicle system that consists of the engine, torque converter, automatic transmission, and the vehicle itself.
Chapters 5 and 6 can be considered as the core of the book, as these two chapters present the design, analysis, and control of conventional automatic transmissions (AT) which are typically designed with planetary gear trains. Chapter 5 focuses on how multiple gear ratios are achieved by different combinations of clutches and planetary gear trains. A systematic method will be presented in this chapter for the design and analysis on the gear ratios and clutch torques of automatic transmissions. The chapter also gives an in‐depth analysis of the dynamics of automatic transmissions during gear shifts and the general vehicle powertrain dynamics in a systematic approach, using an eight‐speed production automatic transmission as the example in the case study.
Chapter 6 concentrates on hardware and software technologies of both component and system levels which are applied in the control systems for the implementation of transmission functionalities. The chapter begins with the functional descriptions of the hardware components, including hydraulic components, electronic sensors, and solenoids. The chapter then presents transmission control system configurations and the related design guidelines. Examples based on the production transmissions of previous and current generations are used to demonstrate the operation logic and functions of the control systems. A specific section is devoted to present concurrent transmission control technologies commonly applied in the automotive industry. This focuses on the accurate clutch torque control during gearshifts and torque converter clutch actuation. The chapter ends with the identification of control variables and control system calibration.
Chapter 7 mainly presents the design and control of belt type continuously variable transmissions (CVT), starting with the structural layouts of CVT systems and key components, including the basic CVT kinematics and operation principles. Topics are concentrated on force analysis during the CVT’s operations, and the mechanisms for torque transmission and ratio changes. The chapter provides details of control system design and the analysis of the control of ratio changing processes. CVT system control strategies, including continuous ratio control, stepped ratio control, and system pressure control are also presented.
The design and control of dual clutch transmissions (DCT) are covered in Chapter 8. The chapter concentrates on the dynamic modeling and analysis of DCT operations, including DCT vehicle launch and shifts. DCT control system design, and shift and launch control processes are included here, and the chapter also dedicates a specific section to DCT clutch torque formulation during launch and shifts, using an electrically actuated dry DCT as the example in the case study.
Chapter 9 covers power train systems for pure electric vehicles (EV). It includes several key technical topics: design optimization and control of electric machines for EV applications, power electronics for electric power transmission and inverter design, and system control under various operation modes. The chapter also includes a section on mechanical transmissions with a fixed ratio or two ratios which are specifically designed for pure electric vehicles. Two‐speed or multi‐speed automated gear boxes enable EV driving motors to operate within the speed range for optimized efficiency and performance.
Finally, hybrid powertrain systems are discussed in Chapter 10, which presents various hybrid powertrain configurations including series, parallel, and complex architectures. It provides detailed analysis of the operation modes and operation control for hybrid vehicle powertrain systems. Production hybrid vehicles are used as case studies in mode analysis and operation control.
As highlighted above, each chapter of the book is dedicated to a specific transmission, and readers may choose the chapter of interest to read. If the book is used as a textbook, the course syllabus can follow the order of the chapters. If the book is used as a reference, readers with transmission expertise may just choose the chapter of interest, and those readers without broad expertise may wish to first read Chapters 1 and 4 and then read the chapter of interest.
The authors would like to express their hearty thanks for the help received from friends and colleagues in preparing the manuscript. We would like to thank especially Prof. Qiu Zhihui of Xian Jiaotong University and Prof. He Songping of Huazhong University of Science and Technology for their help in drawing the pictures for this book. We also want to thank the publisher, John Wiley & Sons, for giving us the opportunity to publish this book, and we dedicate our deep appreciation to Ms Ashmita Rajaprathapan for her invaluable contributions in editing and finalizing the book. Lastly and most importantly, the authors would like to express their thanks to engineers, scholars, and researchers who have contributed to the technologies of vehicular power transmission systems and whose work may or may not have been specifically acknowledged in the reference lists.