Методическое пособие для студентов iv курса очного и заочного обучения специальности 26. 05. 07 "Эксплуатация судового электрооборудования и средств автоматики"
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Федеральное агентство морского и речного транспорта Федеральное бюджетное образовательное учреждение высшего образования Волжский государственный университет водного транспорта Кафедра иностранных языков и конвенционной подготовки О.И. Коваль English for Electrical Engineers Методическое пособие для студентов IV курса очного и заочного обучения специальности 26.05.07 - "Эксплуатация судового электрооборудования и средств автоматики".Нижний Новгород Издательство ФГБОУ ВО «ВГУВТ» 2019 Федеральное агентство морского и речного транспорта Федеральное бюджетное образовательное учреждение высшего образования Волжский государственный университет водного транспорта Кафедра иностранных языков и конвенционной подготовки О.И. Коваль English for Electrical Engineers Методическое пособие для студентов IV курса очного и заочного обучения специальности 26.05.07 - "Эксплуатация судового электрооборудования и средств автоматики".Нижний Новгород Издательство ФГБОУ ВО «ВГУВТ» 2019 УДК 811.111К 56 Рецензенты: В.В. Волкова – доцент, канд. культурологии Коваль, О.И. English for Electrical Engineers: методическое пособие для студентов IV курса очного и заочного обучения специальности 26.05.07 - "Эксплуатация судового электрооборудования и средств автоматики". Целью пособия является развитие навыков чтения и перевода профессионально-ориентированных текстов, а также умений устной и письменной речи. Методическое пособие состоит из 9 разделов, каждый из которых включает в себя тематический словарь, тексты, упражнения. Работа рекомендована к изданию кафедрой иностранных языков и конвенционной подготовки (протокол № 4 от 16.05.2019 г.). © ФГБОУ ВО «ВГУВТ», 2019 UNIT I. SHIP’S DC ELECTRIC MACHINES 1. Read and remember the following words and word combinations.
2. Read and translate the text. THE CONSTRUCTION D.C. machines converting mechanical energy into electrical one are referred to as D.C. generators. Those, on the other hand, which convert electrical energy into mechanical one, are spoken of as D.C. motors. D.C. machines are reversible and, therefore, identical in construction. They are composed of two main parts - the stationary part which is called the frame provided with the main poles and the commutating poles, and the rotating part which is said to be the armature, its windings and commutator being positioned on it. The frame is made of steel in the form of a closed magnetic conductor. The main poles for the purposes of decreasing the losses are assembled of sheet steel laminations. Mounted on them, the field windings are built of copper isolated conductors. The main poles are intended to produce the main magnetic flux. The commutating poles are also made of steel and arranged midway between the main poles. Their windings as well as those of the main poles are built of copper conductors. The commutating poles with the windings are designed to ensure non-sparking operation of an electric machine. The armature makes up a cylindrical core made of sheet steel laminations, a two-layer winding being fixed in their slots. The former is built of sections made of isolated copper conductors. The commutator is constructed of separate copper bars isolated from each other and from the frame. The section leads of the armature winding are connected to the bars. The commutator is designed for the conversion of an alternating e.m.f. induced in the armature winding into a direct one. The brushgear is an element designed for collecting the current from the armature winding and leading it to the latter. It is composed of brushes, brush-holders, brush-studs, brush-rockers and current collecting bars. The commutator and the brushgear are the most essential parts of a d.c. machine, its reliable operation being dependent on their condition. 3. Match the following English and Russian word combinations. a) to convert energy, identical in construction, to be made up of two parts, for the purpose of decreasing losses, designed for, reliable operation b) похожий по строению, с целью сокращения потерь, преобразовать энергию, надежная работа, состоять из двух частей, предназначенный для. 4. Match the synonyms. a) to be made up of, to convert, to ensure, to construct, to connect, essential parts, to employ b) to use, to be comprised of, to transform, to provide, to join, to build 5. Answer the questions. 1. What type of D.C. machine is referred to as a D.C. generator? 2. What type of D.C. machine is spoken of as a D.C. motor? 3. What are the two main parts of D.C. machines? 4. What is the frame composed of? 5. Is the construction of the commutating poles identical to the one of the main poles? 6. Are the commutating poles intended for the same purposes as the main poles? 7. What does the armature make up? 8. What is the commutator designed for? 9. What elements is the brushgear constructed of? What is it designed for? 6. Read and translate the text. THE PRINCIPLE OF OPERATION The operating principle of a D.C. machine is built upon the laws of electromagnetic induction and electromagnetic force. As the armature is rotated in the magnetic flux of the main poles by a drive motor, the E.M.F. is induced in the armature winding. In the loaded machine, the e.m.f. brings into existence the current with which it coincides in direction. This current interacting with the magnetic flux produces the electromagnetic torque directed in opposition to that produced by a prime mover. As this takes place, the machine operates as a generator. The mechanical power consumed from the drive motor is converted into the electrical one and is given up to the mains. When a d.c. machine is connected to the electrical source of supply, the current is generated in the armature winding. Interacting with the magnetic flux of the poles, it produces the electromagnetic torque which brings into rotation the armature. The e.m.f. directed in opposition to the current direction is induced in the armature winding. In this case the machine works as a motor. The electrical power consumed from the mains is converted into the mechanical one. 7. Match the following English and Russian word combinations. a) the operating principle, to coincide in direction, to take place, source of supply, to bring into rotation, to produce electromagnetic torque, to interact b) совпадать по направлению, приводить к появлению, принцип действия, источник питания, взаимодействовать, происходить, приводить к вращению. 8. Match the synonyms. a) induce, interact, convert, rotate, generate b) turn, cause, act together, change, produce 9. Answer the questions. 1. What laws is the operative principle of a D.C. machine built upon? 2. How can the operative principle of a D.C. machine be described? 3. In what case does a D.C. machine operate as a D.C. generator? 4. Under what condition does a D.C. machine work as a D.C. motor? 5. What happens to the electrical power consumed from the mains when a D.C. machine works as a motor? 10. Speak about ship’s D.C. electric machines. |