Exercises. I. Use the following words and word combinations in sentences of your own:

I. Use the following words and word combinations in sentences of your own:

a toothed gear, gearing, to hob, to run, to generate, rotary motion, intersecting shafts, spur gearing, bevel gearing, worm gearing, driven shaft, angular velocity, positive motion, inserted key

II. Answer the following questions:

1. What is a gear and what is it used for? 2. Where do gears replace belt-and-pulley drives? 3. What types of shafts do you know? 4. V/hat do types of gears depend on? 5. According to what features may gears be classified? 6. What kinds of teeth cut on the gear face do you know? 7. What main types of gears can you enumerate? 8. By what processes are gear teeth produced?

III. Choose synonymical groups out of the following list:

velocity, to transmit, to intersect, smooth, to converge, to transfer, speed, to cross, quiet, to approach

IV. Underline the suffixes and prefixes and translate into Russian the following groups of words:

controllable, controller, incontrollable; caller, calling, recall; section, sectional; intersect, intersection, non-intersecting

V. Translate the following sentences observing different meanings of the words in italics:

1. When the rain has stopped I noticed a worm on the lawn of our garden. 2. Worm gearing is applied to transmit power between shafts placed at right angles to each other. 3. The Great October Revolution broke out in 1917 and liberated the working class in our country from the yoke of capitalism. 4.Eccentric gears are applied for transmitting a varying angular velocity for a portion of revolution. 5. I locked the door of my flat and left the key on the shelf. 6. Gears are mounted on shafts by means of keys.

VI. Find in the text English equivalents of:

Передача с внешним зацеплением; передача с внутренним зацеплением; винтовая передача; закладная шпонка; прямой зуб; кривой зуб, винтовой зуб, косой зуб, реечная передача, фрикционная передача, цилиндрическое зубчатое колесо, коническое зубчатое колесо, шестерня с косыми или спиральными зубьями, шестерня с шевронными зубьями, вращательное движение, давление, зубчатая передача, червячная передача

VII. Make up questions to which the italicized words are the answers:

I. Modem requirements for gears demand that they run quietly at high speeds. 2. Gear-cutting machines have been developed for the rapid mass production of similar parts. 3. The gear blank is pressed on an arbor and held between centers of the dividing head and the index tailstock. 4. Bevel gearing is used to transmit power between two shafts whose axes intersect each other. 5. Spur gearing is used to transmit power between parallel shafts.

VIII. Using the following words and word combinations describe the bevel gears shown in Figs 36 and 37 and explain the difference between their teeth:

bevel gears, to be used, to transmit power, two shafts, axes, to intersect each other, the teeth, to be straight or spiral, Fig. 36, one can see, the straight bevel gears, to converge, a common point, to be called the apex, Fig. 37, a spiral bevel gear, to have helical or spiral teeth, to have been cut, a conical surface, to curve toward or away, the apex, helical or spiral gears, to be applied, operation, parallel shafts, high speeds

IX. Giving answers to the following questions describe the difference between gearings shown in Figs 39 and 40:

1. What types of gearings do you see in Figs 39 and 40? 2. What type of gearing do external and internal gearings belong to? 3. Are the teeth in Figs 39 and 40 straight or helical? 4. How must two shafts be placed when external and internal gearings are used for transmitting power between them? 5. What engagement of two gears does an external gearing provide? 6. What engagement of two gears does an internal gearing provide?

X. Look at Figs 38, 41 and 42 and describe in detail the difference between the given gearings.

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