ТОМСКИЙ ПОЛИТЕХНИЧЕСКИЙ УНИВЕРСИТЕТ Государственное образовательное учреждение высшего профессионального образования «ФЕДЕРАЛЬНОЕ АГЕНТСТВО ПО ОБРАЗОВАНИЮ» ____________________________________________________ М.В.Горбенко, Н.Б.Кривцова АНГЛИЙСКИЙ ЯЗЫК ТЕОРИЯ МЕХАНИЗМОВ И МАШИН ПРОФЕССИОНАЛЬНАЯ СОСТАВЛЯЮЩАЯ ЯЗЫКОВОЙ ПОДГОТОВКИ Учебно-методическое пособие для студентов машиностроительных специальностей ТОМСК 2006 ББК Ш143.21-923 УДК 802.0:800:37 Г 681 Горбенко М. В., Кривцова Н. Б. Г 681 Теория механизмов и машин. Профессиональная составляющая языковой подготовки: Учебно-методическое пособие. Изд. 2-е исправленное и дополненное. – Томск: Изд-во ТПУ, 2006. – 110 с. Пособие предназначено для выработки и совершенствования навыков профессионального общения инженеров-механиков на английском языке. В пособии приведены аутентичные тексты, соответствующие дисциплине «Теория механизмов и машин», различного уровня сложности, отражающие современные направления в данной области как отечественных, так и зарубежных ученых, упражнения к текстам и словарная база. Методика изложения, структура оформления оригинальных англоязычных источников сохранена. Предназначено для студентов машиностроительных специальностей Томского политехнического университета. УДК 802.0:800:37 Рекомендовано к печати Редакционно-издательским советом Томского политехнического университета Рецензенты К.филол.н., доцент каф. методики ТГПУ Зырянова Е. В. К. физ. мат. н., доцент каф. прикладной механики и материаловедения ТГАСУ Шиляев А. М. © Томский политехнический университет, 2006 © Оформление. Издательство ТПУ, 2006 2 CONTENT I. STRUCTURAL AND KINEMATIC ANALYSIS OF LEVER MECHANISMS……………………………………………………………... 4 1. Mechanics of Machines and its Basic Sections……………………........... 4 2. Basic Concepts and Definitions……………………………………...…… 6 Exercises……………………………………………………………….. 7 II. THE STRUCTURAL AND KINEMATIC ANALYSIS OF MECHANISMS……………………………………………………………... 12 1. Structure of Mechanisms…………………………………………………. 12 2. Classification of Kinematic Pairs…………………………………………. 13 Exercises………………………………………………………………... 17 3. Kinematic Chains…………………………………………………………. 21 4. Classification of mechanisms…………………………………………….. 26 Exercises……………………………………………………………….. 29 Appendix II.1………...……………………………………………............ 33 Appendix II.2………………………………..……………………............ 34 Appendix II.3………………………….………………………………….. 35 III. TYPES OF GEARS……………………………………………………... 36 1. Types of Gears……………………………………………………………. 36 2. Nomenclature……………………………………………………………... 38 3. Tooth Systems……………………………………………………………. 40 Exercises……………………………………………………………….. 43 IV. GEAR AND GEARING (PART I)……………………………………… 47 1. Types of Gears……………………………………………………………. 47 2. Definitions of Gear Terms………………………………………………... 48 Exercises……………………………………………………………….. 51 GEAR AND GEARING (PART II) …………………………………….. 55 Exercises……………………………………………………………….. 59 BEVEL GEARING – GENERAL……………………………………….. 65 Straight bevel gears………………………………………………………. 67 Exercises……………………………………………………………….. 69 Appendix IV.1………………………………….………………………… 71 Appendix IV.2………………………………….…………………............ 72 Appendix IV.3…………………………………………….………............ 73 V. PLANETARY GEAR DRIVES………………………………………….. 74 1. A Simplified Approach for Determining Power Losses and Efficiency of Planetary Gear Drives………………………………….................................. 74 2. Equivalent System Concept………………………………………………. 77 3. Simple Planetary Train…………………………………………………… 79 4. Compound Systems………………………………………………………. 83 Exercises………………………………………………………………... 92 VI. CAMS AND CAM DESIGN……………………………………………. 96 Exercises………………………………………………………………... 106 REFERENCES……………………………………………………………… 109 3 I. STRUCTURAL AND KINEMATIC ANALYSIS OF LEVER MECHANISMS Terminology study of component parts of mechanisms Classification of mechanisms and machines. Links. Kinematic pairs. Structural groups (Assur’s groups). Methodical materials: − text; − models of mechanisms; − pictures with kinematic pairs, mechanisms, schemes of mechanisms; − tasks on the theme. INTRODUCTION 1. Mechanics of Machines and their Basic Sections Mechanisms are widely used in all branches of modern technology. The same types of mechanisms having the same computation and design methods are used in machines of various branches. The Theory of Machines and Mechanisms (TMM) develops general kinematic and dynamic methods of design applied to mechanisms of various branches of engineering. The special disciplines studying the theory and methods of mechanisms and machines’ design, used in separate branches of engineering, widely use general methods developed in ТММ, therefore ТММ is a general- engineering discipline. Base for ТММ is physics, mathematics and theoretical mechanics. The TMM jointly with sciences "Strength of Materials and Theory of Elasticity", "Machine Elements" and "Production Engineering" is theoretical basis for current engineering industry. The Theory of Machines and Mechanisms considers the scientific basis of machine design and their investigation methods. It is a science studying machines both as a complex unit and as separate links having the purpose of their analysis and providing people with knowledge for creation of new ones. The purpose of creating of machines is to increase the productivity and to make worker’s manual labour easier or to extend his or hers physical and intellectual opportunities. The term "machine" covers a great number and variety of objects used by a man for labour and physiological functions. The following definition is common: The machine is a device intended for transformation of energy, 4 materials and information. The machines are means of production that use the forces nature of to facilitate work. From the point of view of functions, carried out by machines, it is possible to classify all machines into the following groups: a) Power machines; b) Material-working machines; c) Information (supervisory control) machines; d) Cybernetic. The power machine is a machine intended for conversion of energy from one form to another (transforming any kind of energy into mechanical one – the machine-engine, and vice versa – machine-generator). The material-working machine is a machine for conversion of materials. The working machines are subdivided into transport and technological ones. The transport machine is a working machine, in which conversion of materials consists only in changes of their position in space. The technological machine is a working machine, in which the conversion of a material consists in changes of the form, location or properties of a material or machined object. The information machine is a machine for conversion of information. These machines are subdivided into supervisory control machines and computing ones. The cybernetic machine is a machine replacing or simulating various mechanical, physiological or biological processes, inherent to a man and animate nature. If the processes of energy or materials conversion are carried out without direct participation of man, the machines performing such operations are named automatic-machine devices. The set of the automatic-machine devices connected with each other and intended for performance of certain technological processes, is called an automatic transfer line. The set of the machine-engine, transmission, working machine and supervisory control machine is called a machine unit. It can be represented by the diagram: The supervisory control machine Transfer Engine Actuator Product mechanism 5 The actuator consists of one or several mechanisms. Mechanism – is a system of bodies intended for conversion of motion of one or several bodies into the required motion of other ones. By the functional purpose all mechanisms are subdivided into the following kinds: 1. Mechanisms of engines and converters. 2. Transmissions. 3. Executive mechanisms (actuators). 4. Mechanisms of control and regulation. 5. Feeders, transporters, sorters of machined objects. 6. Mechanisms of the automatic count, weighing and packing. The mechanisms which are included in the structure of a machine can incorporate firm, liquid, gaseous bodies, electrical and magnetic devices, which work according to the basic principles of mechanics, thermal physics, electrical engineering and electronics. Therefore, the Theory of Machines and Mechanisms is the science studying the structure, kinematics and dynamics of mechanisms in connection with their analysis and synthesis. 2. Basic concepts and definitions All problems of the theory of mechanisms can be divided into two groups. The first group of problems is connected with the research of structural, kinematic and dynamic properties of mechanisms, i.e. with their analysis. The second group of problems deals with the design of mechanisms with the predetermined structural, kinematic and dynamic properties for realization of required movements, i.e. with the synthesis of mechanisms. The mechanism’s movement depends on their structure and applied forces. Therefore, in the study of the theory of mechanisms, it seems to be convenient to divide all problems of mechanisms’ analysis into two parts: 1. Structural and kinematic analysis. 2. Dynamic analysis of mechanisms. The purpose of structural and kinematic analysis of mechanisms is to study the mechanism’s structural theory and research the motion of mechanisms from the geometrical point of view, without the consideration of the forces causing this motion. The purpose of dynamic analysis is to study the methods of force definition, acting on the elements, forming a mechanism during their motion, and to study the interrelation between the motion of the elements, their masses and acting forces. 6 EXERCISES TO THE CHAPTER “MECHANICS OF MACHINES AND THEIR BASIC SECTIONS” 1. Learn these words and phrases 1. branch - отрасль 2. mechanism - механизм 3. kinematic - кинематический 4. dynamic method - динамический метод 5. apply - применять 6. computation - применение , вычисление 7. therefore - поэтому; следовательно 8. jointly - совместно 9. strength of materials - сопротивление материалов 10. discipline - дисциплина 11. theory of Elasticity - теория упругости 12. producing Engineering - технология производства 13. consider - рассматривать 14. productivity - производительность 15. manual labour - физический труд 16. device - механизм, прибор 17. carry out - выполнять 18. power machine - энергетическая машина 19. material working machine - технологическая машина 20. supervisory control machine - контрольно-управляющая машина 21. information machine - информационные машины 22. cybernetic machine - кибернетическая машина 23. conversion - превращение 24. property - свойство 25. location - размещение 26. inherent - присущий 27. animate nature - живая природа 28. automatic transfer line - автоматическая линия 29. automatic –machine device - машина-автомат 30. transmission - передача, коробка передач 31. working machine - станок 32. machine unit - машинный агрегат 32. actuator - исполнительный механизм 33. converter - преобразователь 34. executive mechanism - исполнительный механизм 35. feeder - питатель, подающий механизм 7 36. gaseous body - газообразное тело 37. thermal physics - тепловая физика 38. liquid body - жидкое тело 39. deal with - иметь дело с чем-либо 40. geometrical - геометрический 41. interrelation - взаимоотношения 42. acting force - действующая сила 43. structural analyses - структурный анализ 44. dynamic analyses - динамический анализ 45. intend for - предназначаться 46. investigation method - метод исследования 2. Read and translate the words having the same root: Act-action-active-activity-interaction Different-difference-differentiate-indifference Locate-located-location Apply-application Engine-engineering-engineer Create-creation-creative-creativity Performance-performing-perform Similar-similarity-similarly Technology-technological-technician-technique Produce-production-productivity-productive Conversion-convert 3. Form words by means of the following prefixes or suffixes and translate them into Russian: -action: consider -ly: general, final -ion: rotate, act, direct -al: rotation, dimension -mis: understand -ex: change -ant: distance 4. Give Russian equivalents to the following 1. strength of materials 12. subdivide 2. facilitate 13. production engineering 3. actuator 14. apply 4. participation 15. material-working machine 8 5. location 16. transmission 6. deal with 17. simulate 7. acting forces 18. feeder 8. executive forces 19. gaseous body 9. liquid 20. therefore 10. inherent 21. consider 11. extend 22. intend for 5. Give English equivalents to the following 1. превращение 13. машина-двигатель 2. совместно с (электрогенератор) 3. развивать 14. выполнять 4. механизм, прибор 15. контрольно-управляющая 5. кибернетический машина 6. основa 16. автоматическая линия 7. питатель 17. тепловая физика 8. геометрический 18. свойство 9. взаимоотношение 19. физический труд 10. замещать 20. соединять 11. производительность 21. обеспечивать 12. дисциплина 22. методы проектирования 6. Match the words and phrases in column A with those in column B A B 1. machine elements A. замещать 2. branches of engineering B. средства 3. automatic counts C. взаимоотношение 4. converter D. автоматический приборный 5. transmission механизм 6. replace E. сортировочное устройство 7. automatic - machine- F. детали машин device G. отрасли инженерии 8. sorter of machined objects H. коробка передач 9. means I. автоматический подсчет 10. interrelation J. преобразователь 7. Give definitions to the following words and phrases 1. Machine unit 2. Mechanism 9 3. Cybernetic machine 4. Machine 5. Power machine 6. Automatic- machine device 7. Technological machine 8. Information machine 9. Automatic transfer line 10. Material-working machine 8. Match the phrases in column A with those in column B A B 1. From the point of view of …to make worker’s manual labour functions easier. 2. The working machines …studying machines. 3. The purpose of creating of …we can classify all mechanisms into 6 machines is groups. 4. The mechanism movement …is to study the methods of force 5. The purpose of dynamic definition, interrelation between analysis elements’ motion. 6. It is the science …are subdivided into 2 groups. …depends on their structure and applied forces. 9. Fill in the gaps. The machine is a …… intended for transformation of energy, …… and information. The power machine is a machine …… for conversion of energy from one form to …… (transforming any kind of energy into mechanical – the machine-engine, and vice versa – machine-generator). The material-working machine is a machine for conversion of …… . The working machines are …… transport and …… ones. The transport machine is a …… machine, in which conversion of materials consists only in …… of its position in space. The technological machine is a working machine, in which the conversion of a material consists in changes of the …… , location or …… of a material or machined object. The information machine is a machine for conversion of …… . These machines are subdivided into …… and computing ones. 10