III. Answer the following questions.

1. What machines of recent origin do you know?

2. What machines of rapid transit do you know?

3. What kind of motors is now used instead of muscle power to operate the machines?

4. What is the role of machines in the home?

5. Have machines completely transformed our life?

Test yourself:

1. Choose the right variant.

1. A machine is a device that

a) uses force to accomplish something.

b) transmits and changes force or motion into work.

c) all of the mentioned above.

2. A machine receives input from

a) an energy source and transforms it into output in the form of mechanical or electrical energy.

b) an energy source and transforms it into output in the form of mechanical energy.

c) an energy source and transforms it into output in the form of electrical energy.

3. Machines whose input is a natural source of energy are called

a) electric motors.

b) prime movers.

c) generators.

4. Machine elements are

a) basic mechanical parts used as the building blocks of most machines.

b) assembled together to form what we call as complete machine, which performs various applications.

c) individual parts of the machine that move and impact on other parts to make the machine work.

5. General-purpose machine elements can be used

a) in some application.

b) only in specific applications.

c) in any application.

6. Mechanisms are used

a) to transform input forces and movement into a desired set of output forces and movement.

b) to convert between one type of motion and another.

c) all of the mentioned above.

2. Change the words in brackets from Ukrainian into English.

Machine design is an important part of engineering applications, but what is a machine? Machine is the (1) винахід that comprises of the stationary parts and moving parts combined together to generate, transform or utilize the mechanical energy. All the machines are made up of elements or parts and units. Each element is a separate part of the machine and it may have to be designed separately and in assembly. Each element in turn can be a complete part or made up of several small pieces which are joined together by (2) заклепування, (3) зварювання etc. Several machine parts are assembled together to form what we call as complete machine.

Here are some examples of the machines:

- (4) Токарний верстат utilizes mechanical energy to cut the metals. The other types of machine tools also perform the same task.

- (5) Турбіни produce mechanical energy.

- (6) Компресори use mechanical energy to compress the air.

- (7) Двигуни consume the fuel and produce mechanical energy.

- (8) Холодильники and (9) кондиціонери use mechanical engineering to produce cooling effect.

3. Fill in the right words into the sentences.

Mechanism; specific device; machines; mechanisms; common; machine

1. General purpose elements are … to various types of machines serving different applications. Examples of these elements are nuts, bolts, keys, axles, shafts, couplings, bearings etc.

2. Special purpose elements are used only in the … type of machine. For instance piston and connecting rods are used in the engines and compressors, while blades are used in the turbines and blowers. Some other examples are cam shafts, push roads, crankshaft, cylinder etc.

3. A mechanism is a … designed to transform input forces and movement into a desired set of output forces and movement.

4. …generally consist of moving components such as gears and gear trains, belt and chain drives, cam and follower mechanisms, and linkages as well as friction devices such as brakes and clutches, and structural components such as the frame, fasteners, bearings, springs, lubricants and seals, as well as a variety of specialized machine elements such as splines, pins and keys.

5. The combination of force and movement defines power, and a … is designed to manage power in order to achieve a desired set of forces and movement.

6. A mechanism is usually a piece of a larger process or mechanical system. Sometimes an entire machine may be referred to as a mechanism. Multiple mechanisms are…