3. Fill in the appropriate words in the sentences.

general purpose elements; special purpose elements; mechanical parts; types; machines

1. Machine elements are basic … used as the building blocks of most machines.

2. All the … are made up of elements or parts and each element may have to be designed separately and in assembly.

3. The machines elements are classified into two main …: general purpose elements like nuts, bolts, bearings, couplings and special purpose elements like piston, crankshaft etc.

4. The elements which are common to various types of machines serving different applications are called...

5. The elements that are used only in the specific type of machine are called as...

4. Answer the following questions.

1. What are machine elements?

2. What are the main parts of machine elements?

3. Where can general-purpose elements be used? Give their examples. Do they operate on the same principles of force and motion?

4. What is the special-purpose machine element? Give the example.

5. What is the difference between general-purpose elements and special purpose elements?

6. What do engineers seek in designing a machine element?

7. What are these factors?

8. What is the basic function of the machine element?

Mechanisms

Exercises to the subject:

1. Scan the text quickly to find out which of these mechanisms are mentioned:

cam

tap

pendulum

foot pump

escalator

Mechanisms are an important part of everyday life. They allow us to do simple things like switch on lights, turn taps, and open doors. They also make it possible to use escalators and lifts, travel in cars, and fly from continent to continent.

Mechanisms play a vital role in industry. While many industrial processes have electronic control systems, it is still mechanisms that deliver the power to do the work. They provide the forces to press steel sheets into car body panels, to lift large components from place to place, to force plastic through dies to make pipes.

All mechanisms involve some kind of motion. The four basic kinds of motion are:

Rotary: wheels, gears, and rollers involve rotary movement.

Oscillating: the pendulum of a clock oscillates – it swings backwards and forwards.

Linear: the linear movement of a paper trimmer is used to cut the edge of the paper.

Reciprocating: the piston in a combustion engine reciprocates.

Many mechanisms involve changing one kind of motion into another type. For example, the reciprocating motion of a piston is changed into a rotary motion by the crankshaft, while a cam converts the rotary motion of the engine into the reciprocating motion required to operate the valves.

2. Find the following words and phrases in English in the given text: вмикати світло; повертати крани; життєво важлива роль; пресувати сталеві листи на корпуси автомобілів; піднімати великі комплектуючі з місця на місце; видавлювати пластмасу через штампи для виготовлення труб; основні види рухів; обертальний; гойдання; маятник годинника; лінійний; пристрій для нарізання паперу; зворотно-поступальний рух; клапан; колінчастий вал; кулачок.