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About this book

This book presents essential information on systems and interactions in automotive transmission technology and outlines the methodologies used to analyze and develop transmission concepts and designs. Functions of and interactions between components and subassemblies of transmissions are introduced, providing a basis for designing transmission systems and for determining their potentials and properties in vehicle-specific applications: passenger cars, trucks, buses, tractors and motorcycles. With these fundamentals the presentation provides universal resources for both state-of-the-art and future transmission technologies, including systems for electric and hybrid electric vehicles.

Table of Contents

Frontmatter

1. Core Task of Vehicle Transmissions

The fundamentals of power train design constitute the central element of this chapter and serve as the basis for the methodological competence and system competence for vehicle transmissions. The chapter starts with a discussion of the forces on the vehicle and the composition of the traction demand. This is juxtaposed with the provision of torque of the power train. The relationship of these two factors, demand and traction force, will be shown for the case of driving at constant velocity, as well as for acceleration processes in Sects. 1.1 and 1.2.
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

2. Shift Dynamics and Shift Comfort

To this point, requirements imposed on the transmission have been introduced that are satisfied via multiple gears and appropriate gear ratio change. In Sect. 2.1, this chapter describes the various phases of a shift sequence and compares the ideal shift sequence with shift sequences that are not acceptable in terms of quality. The shift-related torque changes as well as the engine excitations and torque variations cause the powertrain to vibrate. In Sect. 2.2, the occurring vibrations and eigen frequencies are discussed, as are measures for reducing these vibration occurrences.
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

3. Power Transfer Elements

With the requirements cited in Chap. 1 the power transfer elements are discussed below from the system perspective. Transmissions can be configured through the combination and interconnection of these elements together with the actuation systems (Chap. 4); a selection is presented in Chaps. 6 and 8. These elements are in the power flow between the engine and the wheels and fulfill the functions of speed and torque adjustment, in stationary as well as transient operating states. The most important elements are discussed in separate sections; design principles and commonly used arrangements are shown. In an abstracted presentation in Sect. 3.1, first the physical fundamentals and active principles are introduced. The different characteristics and properties can be worked out on the basis of the physical fundamentals and active principles.
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

4. Actuation, Servo, and Auxiliary Systems

The core transmission tasks introduced in Chap. 1 require the tasks of power transfer and shifting or modulation as described in Chap. 3. For the latter actuation and servo systems are needed to provide the ratio changes and to control the launch devices. The transmission must also be lubricated and cooled, and this is done with appropriate auxiliary systems. For this, the individual requirements and functionalities differ depending on the transmission design (see Chap. 6).
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

5. Controls

Manual transmissions contrast with automatic manual transmissions, dual clutch transmission, automatic transmissions and continuously variable transmissions in that these latter are equipped with additional components that allow partial or complete automation of the shift event. This chapter gives a general description of controls and individual aspects are introduced using examples of dual clutch transmissions.
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

6. Transmission Designs for Passenger Cars

This chapter focuses on designs for passenger car transmissions which are used in production for smaller or larger volumes. Transmission examples beyond the passenger car market are introduced in Chap. 8. The passenger car examples presented here can be divided in two groups: Stepped transmissions and continuously variable transmissions (CVTs). Stepped transmissions have a finite number of gear ratios.
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

7. Power Train Electrification

Already in Chaps. 1 and 6 electrification was briefly touched. This chapter is dedicated to electric and hybrid propulsion. The reasons for having an extra chapter are:
Specifics of electric drives as standalone propulsion in combination with internal combustion engines are subject of this chapter. In this sense and context, electric propulsion is defined as the system of an electric motor, the matching power electronics as well as the required sensors and safety concepts.
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

8. Transmission Applications Beyond the Passenger Car Sector

Beyond the applications of the passenger vehicle transmission introduced in Chap. 6, additional requirements and specifications apply for transmission systems in commercial trucks, buses, tractors, motorcycles, or race cars. All physical principles presented to this point can be applied in a similar manner. However, additional functions and requirements must be considered in development, while other criteria move into the background. The necessity derived in Chap. 1, of suitable gear ratios and torques of the engine to the respective driving or operating states remains the core function.
Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

Erratum to: The Automotive Transmission Book

Robert Fischer, Ferit Küçükay, Gunter Jürgens, Rolf Najork, Burkhard Pollak

Backmatter

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