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Файл:Английский язык для обучающихся по энергетическим специальностям. Учебное пособие.pdf
to employ |ɪmˈplɔɪ| – использовать
to add – прибавлять
machinery |məˈʃiːn(ə)ri| – техника,
оборудование
to switch on – включать
appliances |əˈplaɪənsɪz| – бытовые
starting torque |ˈstɑːtɪŋ tɔːk| – пус-
to result |rɪˈzʌlt| – приводить к
series winding |ˈsɪəriːz| – обмотка
instead of |ɪnˈstɛd| – вместо
in series – последовательно
certainly |ˈsəːt(ə)nli|– конечно,
so far – пока, до сих пор
winding |ˈwʌɪndɪŋ| – обмотка, ка-
a wide range |reɪn(d)ʒ| – широкий
commutator |ˈkɒmjʊˌteɪtə| – кол-
immersed |ɪˈmɜːst| – погруженный
brushes |ˈbrʌʃɪz| – щетки
countless |ˈkaʊntləs| – бесчислен-
UNIT 15. ELECTRIC MOTOR
Vocabulary
приборы
несомненно
тушка
лектор
ковой крутящий момент
с последовательным соединением
диапазон
ный, несчетный, бесконечный, неисчислимый
The electric moto r is a dev ice employed for transforming one form of energy into another, that is to say, electrical into mechanical. We know it to produce
the rotary mot i on which turns our machinery and various appliances.
We have already seen the generator convert mechanical energy into electrical one. No w the pr ocess is r evers e. It is el ectrici ty th at is suppl ied to t he machine and it is motion that results. It is obvious that generators and motors are
similar in certain respects. In case we put curren t in to th e dynamo instead of our
taking current out, it will rot at e as a motor. Ther e ar e certainly so me di f ferences
in detail but in both of them we find an armatu re with windings, a commutator
and brushes, combined with an electromagnet for producing the magnetic field.
However in an electric motor one shunt winding is not sufficient an d a second
one called a ser ies winding should be added. “Why is it necessary? ”one might
ask. The fact i s that the motor is required to hav e a powerful effect at the very
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moment when the current is switched on, for instance, in an electric train or
tram. Avery strong magnetic field is needed to obtain a so-called powerful
starting torque. This is achieved by adding a s er i es w i n di ng to the magnet coils.
Is connected not in shunt with the armature but in seri es with it, so that all the
heavy starting current passing through the armature winding, now passes
through the s erious field coil and prov ides a strong field necessary f or starting
while the shunt field winding provides the running conditions.
So far nothing was said of what a motor does in our homes. In a modern
home there are man y different elect ric motors in machin es and devices ut ilized
to meet our dail y requirements : to tell the time, to was h clothes, to cool the refrigerator, to clean or brush various things, to shave, to circulate air in a warm
room in a hot day work thanks to electric motors. It follows that in the electric
motors we hav e a valuable and powerfu l appliance capable of fulfilling the required operations exactly and with just the desirable kind of motion, rate of
speed and power . It is readil y switched on, at will, an d it continu es running until we switch i t off again . In our p resent-day wi de use of the motor th ere are often cases when it is simply possible to replace i t by any other suitable eng ine.
Generally speaking, it revolutionized industry by making use of energy that can
be transmitted from great distances.
Fig. 12. The electric motor
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No appliance ev er created by man has p robably such a wide range of size
and such a v ariety of ap plication as a motor. In fact, on the one hand, there are
all kinds of mighty giants in the motor world. These giants are known to perform innumerable operations in coal-mines, in steel mills, chemical factories
and so on, in short, in great numb ers of facto ries an d works. On the other hand,
there exist all kinds of small- sized and even minute motors which are ab le to
power vario us complex machines. The y operate equally well u nder any conditions: high in the air or immersed in water, lowered into a well or on the table of
some famous scientist. Much of our farm equipment is also driven by means of
electric motors. In short, they find the application wherever and whenever suitable, that is, in industry and science, in agriculture and transport.
Countless highly efficient and powerful motors constructed according to
the latest ach ievements of scien ce and engineering are widely employed in our
country today .
Exercises
1. Translate the following sentences.
1. The flow of current being reduced, the speed of the motor is decreased.
2. It is on the above basis that all our power-plants ar e constructed at presen t.
3. We know of this substance having being used at first owing its high quality.
4. Copper being a good conductor, we asked to use it when carrying on our research work. 5. By changing value of the resistance, we can increase the current. 6. Having been used for a long time, the instrument lost its former quality.
7. Were this solid substance heated, it would greatly expand. 8. To observe is
the primary ru le of any ex perimen t. 9. The professor wants us to turn our attention to the problem of semiconductors. 10. The new invention proved to be of
great practical importance.
2. Define the function of the words in bold type.
1. The methods applied improved the quali ty o f t he s ubs tance. 2. The ma-
chine u sed show ed good results. 3. The experiment described attracted every-
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body’s attention. 4. The substances utilized neutralized each other. 5. The
amount of electricity generated depended on the quality of the coal. 6. The
scientists mentioned contributed greatly to the development of science.
3. (a) Form verbs applying the suffix-ize:
civil, revolution, equal, neutral;
(b) Form ver bs appl ying the prefix over-:
load, throw, grow , come, estimate, power, take, run;
(c) Form nouns applying the suffixes -er, -or:
work, translate, act, speak, steam, boil, conduct, engine, fact, heat.
4. Form sentence s usi ng the following word combinations.
A
Model: …the research work to be finished…
I told you about the research work to be finished in time.
1. …the very device to be employed…
2. …the problem to be solved…
3. …the temperature to be measured…
4. … the story to be told…
5. …quite nec essary to transform…
6. …too difficult to translate…
B
1. …know him to…
2. …wanted us to…
3. …expected you to…
4. …is supposed to…
5. …was considered to…
6. …is known to…
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5. Fill in the blanks with the following expressions.
To find appli cati on (in) ; to make us e(o f); to play a p art (in ); to tak e int eres t
(in); to pay attention (to).
1. Many Russi an scientists of the p ast … the development o f Russian science. 2. Lomon osov … not on ly in physics b ut also in ch emistry. 3 . We … minute motors as well as mighty giants. 4. Insulators as well as conductors …
electrical engineering. 5. In Russia great … the peaceful use of atomic energy.
6. Complete the following sentences.
1. A transformer is a device which …
2. A dynamo is a devi ce which…
3. A battery is a device which …
4. A switch is a device which …
5. An engine is a device which …
6. A thermometer is a device which …
7. Speak on.
1. The use of electric motors in industry.
2. The use of electric motors in our everyday life.
8. Look at Fig. 12 and describe it.
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APPENDIX
ADDITIONAL GRAMMAR EXERCISES
Participle
1. This brief description of some of the methods used in our work covers
only a few of the problems encounted.
2. The resistance being very high, the current in the circuit was low.
3. As useful as lasers are becoming, we have hardly yet begun to realize
their ultimate potentialities.
4. The test referred to above can be easily made.
5. There is alw ays wat er vapour in the air, th e amou nt depending upon var-
ious conditions.
6. Until now we have been discussing reactors from which no power is be-
ing taken.
7. The regio n o f highest res i s t an ce i s t he point of co ntact between t h e p i ec-
es being welded.
8. Some o f the effects pro duced by an electric cu rrent are discus sed in the
following cha pt er.
9. The volt age being increased, the fi eld becomes strong enough to cause
the electrons to produce additi onal ions by collision.
10. The filament heated, the electrons leave its surface and travel to the
plate.
11. Multiplying the mass of a moving body by its velocity, we shall get its
momentum.
12. These sug gestions are based on pr actical experience gained in the design of a considerable number of laboratories not to speak of the discussions
with experienc ed workers in the field of thermodynamics.
13. In many instances an apparatus designed for quite a different purpose
was adopted, certain changes being made when required.
14. The probl em having ex cited a g reat deal of discus sion, a s eries of tests
had to be carried out.
15. The oil having been exhausted, the engine stopped.
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16. There are two diagrams in this figure, one of them s howing the relation
between volume and temperature.
17. Working at this new device, the inventor made numerous improve-
ments, the latter resulting from his own experiments.
Gerund
1. They went on studying the nature of that new phenomenon.
2. There are different means of producing an electrical current.
3. We heard of that experiment having been started last week.
4. Radioisotopes may be used in measuring the diffusion of metals.
5. Before discussing the future development in isotope utilization, let us
trace briefly the events leading to its discovery.
6. This moto r is capable of eff ectively operati ng completely sub merged in
water as a thin-shelled can completely protects the stator.
7. An unusual electric motor has b een developed which creates linear mo-
tion directly without going through rotating m ot i on first.
8. In addition to its being used as a wide-range voltmeter, the instrument
can serve as an ammeter.
9. Comparing the performance of these instruments is the only means of
solving the problem under discussion.
10. The trouble was due to the fact that the engine was put into operation
instead of having been tested first.
11. Laboratory testing will expand rapidly at our Insti tute.
12. The value of the accelerating torque determines the time taken by the
motor to reach f ul l speed from the moment of switching on.
13. Some types of motor are not suitable for braking duty, and the re-
quirement must be specified at the time of ordering.
14. One cannot appreciate the marked improvement achieved without
comparing tables II and III.
15. The machine broke on account of its having been made of a delicate
material.
16. We have learned of his starting a series of new laboratory experiments.
17. Normally, stainless steels referred to above are welded without pre-
heating and posthea tin g.
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Infinitive
1. It is necessary that the sample to be analysed be chemically pure.
2. The following precautions should be observed to insure valid results on
our experiment.
3. To find an instrument better suited for our testing was the next problem
to be solved.
4. We know the strength of a current to depend upon the resistance of the
circuit.
5. For a long time the atom was thought to be indivisible.
6. A three-inch tube has been found to be satisfactory but it is entirely
practicable to use greater tubes if needed.
7. The oscill ograph to be us ed for testing purposes is s i mil ar t o t h at u sed in
our laboratory.
8. If considered from this point of view, the problem seems to be rather
complicated.
9. Radium is said to be one and a half million times more rad ioactive than
uranium.
10. Tests have shown the thermometer to be very sensitive.
11. The oscil lator referred to above seems to deli ver only a small amou nt
of power.
12. The instrument to be described here was developed several years ago.
13. To analyze this effect is to take into considerati on all the elements of
the circuit.
14. To analyze this effect we shall consider all the elements of the circuit.
15. We expected this discovery to have produced great changes.
16. It is necessary to explain why the formulas given here are correct.
17. To explain that the formulas given here are correct, it is necessary t o
study them first.
18. To explain why the formulas given here are correct would require considerable space.
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19. The apparatus to be designed is to be used at the power station.
20. This type of engine i s said to have many disadvanta ges.
21. The effect of connecting cells in series is to increase the total voltage.
22. To find out the state of a mass of a gas is quite possible.
23. To find o ut t he state of a mass of a gas one should know its volume, its
pressure and its temperature.
24. The ammeter is the very instrument to measure the electric current.
25. A piece of apparatus which has the ability to maintain one of its terminals at a hig her potential than the o ther, even though the current is allowed to
flow through it, is said to develop an electromotive force.
26. To heat a body we place it in contact with another body at a higher
temperature.
27. We expect most bodie s t o expand when heated.
28. To achieve good results we are expected to proceed in the following
manner.
29. Under su ch condition s laborator y testing is assumed to continue t o expand rapidly.
30. To drive machines requires power.
Passive, Impersonal and Other Constructions
1. Such difficulties are often met with.
2. Three scales of 50, 100 and 250 v ol ts have been decided upon.
3. It is necessary to point out that only brief description will be given here.
4. These capacitances are known to be inter-electrode capacitances.
5. The above possibi l i ty was not given due consideration at first.
6. It is evident that the best shielding is obtained at 0.65 wave length.
7. One could not obtain a good knowledge of the results without repeating
the test.
8. It has been established that this voltage was sufficient.
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9. In the following article the different components of a cable are dealt
with in turn.
10. One should keep in mind all the above-mentioned disadvantages.
11. The device is said to have been described in some earlier papers.
12. One must always be careful when operating this machine.
13. The assistant was asked to complete the experiment.
14. He was supposed to look after the machine.
15. They employ new devices to obtain better resul t s .
16. This machine is often made use of.
17. This invention is considered to be particularly important.
18. It is quite possible that the device under consideration will w ork well.
19. The new power plant is reported to have gone into oper ation.
20. This mechanism is believed to be the best for converting heat into
work.
21. They say that the probl em in question was not give n due attention.
Prepositional Phrases
1. The problem of converting rotary motion to linear motion is an extreme-
ly difficult one due t o t he conditions just menti oned.
2. At first, this make of engine seemed to be very effective.
3. In spite of, or perhaps, because of its apparent simplicity, the scientific
law in question is often misunderstood.
4. The engineer made some remarks with reference to the problem under
consideration.
5. The above phenom enon may be due to two causes.
6. The inventor made a new discovery with regard to the improvement of
his engine.
7. The usual method of producing high-frequency waves is by means of
vacuum tubes.
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