Mechanical Engineering Components

Bolt is used for fastening together two or more parts of machine or a structure. A bolt is a bar with a thread for a nut at one end and a head at the other. By their shape bolts are divided into square-headed, cup-headed, countersunk head and others.

Nut has a threaded hole to engage the threaded end of a bolt or stud and is the locking part of the system. Bolt nuts may be hexagonal, square, wing-nuts and others.

Stud is a bar threaded at both ends and is used for connecting parts.

Lock-nuts and split pins are used to prevent nuts from working loose.

Key is used to secure a fixed position of a part. Usually the key is inserted between a shaft and a wheel in order to fix the latter in definite position on the shaft.

Spindle is a hollow, thin and light type of a shaft.

Screw is a threaded bolt which fastens the parts without a nut.

Bearing is the component on which shafts are supported, or mounted, in order that they may rotate freely. There are different types of bearings-ball, roller, needle bearings.

Washer is the machine element used to prevent nuts or bolts from getting loose.

Spacer has the purpose to facilitate the tightening of the parts fastened to each other.

Gasket is the element preventing leakage of liquids or escape of gases.

Mesh – a working contact (teeth) of gears.

Pivot – a shaft or pin on which something turns.

Gear – a toothed wheel; one of two or more adjustments of a transmission (in motor vehicle).

 

In ancient times mechanics described six principles that formed the basis of all the machinery in the world today. These applications are: the lever, the wheel, the axle, the pulley, the wedge and the screw. All six devices are building blocks for more sophisticated machines. Of the six, the screw is the most functionable, as the thread seamlessly transforms rotary motion to linear one and vice versa.

Throughout the mechanical world, screws provide precise positioning and motion control. Heavy machinery, for example, makes wide use of ball-screws, worms and feedscrews. The procedure of the pieces to be joined should be supported by structural fasteners. Steel or other structures can be fastened together by rivets, bolts, and welds.

Rivets were used quite extensively in the past. Bolts have essentially replaced rivets as the primary means to connect nonwelded structural components.

There are four basic types of bolts in common use. They are designated by ASTM as A307, A325, A490 and A449. A307 bolts are called unfinished or ordinary ones. They are made from low carbon steel. Two grades (A and B) are available. They are used primarily for low-stress connections and for secondary members. A325 and A490 bolts are called high-strength ones. A325 bolts are made from a heat-treated medium carbon steel. A490 bolts are made from quenched and tempered alloy steel and have a higher strength than A325 bolts. They are used for general construction purposes. A449 bolts are also made from quenched and tempered steel and used for anchor bolts and threaded rods.

Welds are filler materials in welding processes. Welding is a very effective means to connect two or more pieces of material together. Welding can be done with or without filler materials. The filler materials used in modern welding processes are electrodes.

 

Exercise 1 . Translate the derivative words with the suffix -ing into Russian:

bearing, fastening, locking, connecting, working, getting, tightening, preventing, building, positioning, welding.

Exercise 2 . Use the verbs in brackets in the proper form in Present Indefinite Tense, Passive:

1. Bolt (to use) for fastening together two parts of a machine.

2. Bolts (to divide) into several types.

3. Lock-nuts (to employ) to prevent nuts from working loose.

4. Shafts (to support) by bearings.

5. Many details (to position) by screws.

6. Metal structures (to fasten) together by various means.

7. Rivets (to use) extensively in the past.

8. The basic types of bolts (to designate) in different sizes.

9. Bolts (to make) from various types of steels.

10. Sometimes several pieces of material (to connect) with the help of welds.

 

Exercise 3 . Complete the sentences:

1. Bolts are used for …

2. Key is used to secure …

3. Screw is a threaded bolt which …

4. Washer is the machine element used to …

5. Spacer has the purpose to …

6. Gasket is the element preventing …

7. There are six principles of mechanics from ancient times: …

8. Various structures can be fastened by …

9. Bolts are used as the means to connect nonwelded …

10. Welds are filler materials in …

Exercise 4 . Insert the proper words into the sentences:

1. A bolt is (стержень) (с резьбой) for a nut.

2. (По форме) bolts (делятся на) various types.

3. (Гайка) has (нарезное отверстие).

4. (Шпилька с резьбой) is a bar threaded at both ends.

5. (Шпонка) is used to secure (фиксированное положение детали).

6. (Винт) is (нарезной болт), which (скрепляет) the parts (без гайки).

7. (Подшипник) is (деталь) on which (вал) is mounted.

8. (Шайба) is the machine element which does not allow (гайкам) and (болтам) get loose.

9. (Прокладка) is the element preventing (вытекание жидкости) or gases.

10. (Шестерня) is the machine element having meshes.

 

Exercise 5 . Find English equivalent to the Russian word:

 

1. контргайка а) wing nut c) lock nut

b) square nut d) hexagonal nut;

2. шайба, прокладка a) cushion c) gasket

b) washer d) key;

 

3. прокладка, a) rivet c) belt

уплотнение b) pin d) gasket;

 

4. вал a) bar c) gear

b) axle d) shaft;

 

5. подшипник a) bolt c) bearing

b) screw d) nut;

 

6. шестерня a) wheel c) pivot

b) gear d) mesh;

 

7. ось a) lever c) spindle

b) axle d) shaft.

 

Exercise 6 . Translate into English:

1. Машиностроение включает в себя детали машин и оборудования.

2. Существует большое разнообразие деталей машин.

3. Все механизмы основаны на шести древних принципах механики.

4. Многие детали используются для соединения и скрепления частей машин и механизмов.

5. Некоторые детали (болт, винт) либо сами имеют резьбу, либо скрепляются с помощью деталей с нарезным отверстием (гайка).

6. Шпилька с резьбой имеет резьбу с обоих концов.

7. Шпонка используется для фиксации положения деталей, например колеса и вала.

8. Широко используемые в прошлом заклепки заменяются болтами.

9. Существуют различные виды подшипников: шариковые, роликовые, игольчатые и т.д.

10. Болты бывают разной прочности, в зависимости от сорта стали и размера.

 

Speaking:

Exercise 7 . Give the summary of the text, using key vocabulary and tell about:

a) the types of details;

b) the aim of their usage;

c) different shapes of components;

d) principles of their working;

e) different components belonging to one and the same group (nuts, bolts, bearings, washers).

Checklist for Section II:

1. How is Passive Voice formed?

2. What is the meaning of the suffix -ing?

3. What steels are used for producing details of machines?

4. What are all details of machines intended for?

 

Section III

Hand Tools

Grammar: Gerund.

Word-formation: suffix –tion (-sion).

Speaking: Types and application of tools in mechanical work.

Practise the reading of the words:

pliers	[plaIəz]
shears	[òIəz]
die	[daI]
square	[skwεə]
gauge	[′geIdჳ]
cutter	[′kΛtə]
grinder	[graIndə]
chisel	[′tòIzəl]

 

Learn the meaning of the words: