Unit 18 Pistons and crankshaft

1. Memorize the new words and word-combinations:

1.to bore out

2.snugly

3.to slide

4.spring

5.to escape

6.gudgeon pin

7.connecting rod

8.to crank

9. piston ring

10. piston stroke

11. end view

висвердлити

щільно

ковзати

пружина

виходити

поршневий палець

шатун

згинати

поршневе кільце

хід поршня

вид ззаду

2. Find the right translation:

1. поршневе кільце

2. поршневий палець

3. хід поршня

4. крутитися

5. вид ззаду

6. шатун

7. щільно прилягати

8. пружинне кільце

9. ковзати дороги та вниз

a) to fit snugly

b) to slide up and down

c) piston stroke

d) spring rings

e) connecting rod

f) gudgeon pin

g) to go round

h) piston ring

i) end view

3. Read and translate the text.

Pistons and crankshaft

So far we have only dealt with the method of supplying the engine with electricity and petrol. We must next discover how the mechanical parts work.

Every engine has cylinders which are really tubes bored out of the cylinder block. The number and size of the cylinders depend on the power that is required. The most common car engines have four or six cylinders. Each cylinder is provided with a piston, which fits snugly within the cylinder walls but is able to slide up and down. The movement of a piston up or down is known as a stroke. Spring rings are fitted round the piston. They press outwards against the cylinder walls to prevent air escaping down-ward or too much oil escaping upward between piston and cylinder.

Pistons are joined to a connecting rod by a “gudgeon pin”. This joint is at the “little - end”. The lower end of the connecting rod is the “big-end” and this is joined to a crankshaft by the “big-end bearing”. The crankshaft is bent, or cranked, so that the up and down movement of the pistons causes it to revolve, rather like the movement of your legs making of your bicycle pedals go round.

4. Answer the questions:

1) What does the number and size of the cylinder depend on?

2) How many cylinders have the most common car engine?

3) What is the function of the piston?

4) What is the purpose of the spring rings?

5) What are pistons joined to?

5. Try to say with one word:

1) main part of an internal- combustion engine, which contains the cylinders

2) hole in the engine block in which a piston moves and combustion takes place

3) part of the engine that moves inside the cylinder and transmits the force of combustion to the crankshaft through a connecting rod

4) metallic bands that are fitted into grooves around a piston to provide a tight seal between the piston and the cylinder walls

5) back-and-fourth movement, like the action of pistons inside cylinders

6) primary shaft in a piston engine that translates the reciprocating motion of the pistons into rotary motion