Rotary engine: 1 — engine block; 2 — pocket; 3 — rotor

The rotary, or Wankel, engine has no piston, it uses rotors instead (usually two). This engine is small, compact and has a curved, oblong inner shape (known as an «epitrochoid» curve). Its central rotor turns in one direction only, but it produces all four strokes. Dispensing with separate cylinders, pistons, valves and crankshaft, the rotary engine applies power directly to the transmission. Its construction allows it to provide the power of a conventional engine that is twice its size and weight and that has twice asmany parts. The Wankel burns as much as 20% more fuel than the con engine and is potentially a high polluter, but its small size allows the addition of emission-control parts more conveniently than does the piston engine. The basic unit of the rotary engine is a large combustion chamber in the form of a pinched oval (called an epitrochoid). Within this chamber all four functions of a piston take place simultane­ously in the three pockets that are formed between the rotor and the chamber wall. Just as the addition of cylinders increases the horsepower of a piston-powered engine, so the addition of combustion chambers increases the power of a rotary engine. Larger cars may eventually use rotaries with three or four rotors.

Flat (Horizontal-Opposed) Engines.A horizontal-opposed engine is like a V -type engine that has been flattened until both banks lie in a horizontal plane. It is ideal for installations where vertical space is limited, because it has a very low height.

Overhead Camshaft (OHC). Some engines have the camshaft mounted above, for over, the cylinder head instead of inside the block (OHC «overhead camshaft» engines). This arrangement has the advantage of eliminating the added weight of the rocker arms and push rods; this weight can sometimes make the valves «float» when you are moving at high speeds. The rocker arm setup is operated by the camshaft lobe rubbing directly on the rocker. Stem to rocker clearance is maintained with a hydraulic valve lash ad­juster for «zero» clearance.

WORDLIST:

internal combustion двигатель внутреннего

engine (ICE) сгорания (ДВС)

reciprocating piston поршень с возвратно-

поступательным ход

rotary engine роторный двигатель

electric starter электрический стартер

crankshaft коленчатый вал

connecting rod шатун

piston stroke ход поршня

intake stroke такт впуска; такт всасывания

partial vacuum частичное разряжение; вакуум

inlet valve впускной клапан

exhaust valve выпускной клапан

compression stroke такт сжатия

push rod штанга толкателя

air and fuel mixture топливовоздушная смесь; рабочая смесь

power stroke рабочий ход, такт

spark plug свеча зажигания; запальная свеча

exhaust stroke такт выпуска, выхлопа

combustion chamber камера сгорания

top dead center (TDC) верхняя мертвая точка

cylinder head головка блока цилиндров

hemispherical полусферический

wedge shape клиновидный

detonation детонация; звук при детонации

engine configuration компоновка двигателя

V-type engineВ-образный двигатель

low hood низкопрофильный капот

torsional скручивающий; торсионный

block distortion деформация блока цилиндров

«epitrochoid» эпитрохоида

emission-control parts устройства снижения (контроля)

токсичности выхлопных газов

pinched oval приплюснутый овал

pocket (зд.) ниша; каверна

horizontal-opposed engine (горизонтальный) оппозитный двигатель

boxer engine оппозитный двигатель

overhead camshaft (OHC). верхний распределительный

(кулачковый) вал

cylinder block блок цилиндров

rocker arm коромысло клапана

valves float неполное открытие/закрытие клапанов

camshaft lobe кулачек (распределительного) вала

hydraulic valve lash adjuster механизм регулировки зазора

привода клапана

clearance зазор; допуск

COMMENTARY:

addition of combustion chamber — увеличение камеры сгорания This engine is small, compact and has a curved, oblong inner shape (known as an «epitrochoid» curve) — Этот двигатель небольшой, компактный, внутренний объем которого имеет продолговатую, закругленную форму, называемой «эпитрохоида».

Horsepower is a unit of power for measuring the rate at which a device can perform mechanical work. Its abbreviation is hp. One horsepower was defined as the amount of power needed to lift 33,000 pounds one foot in one minute.

EXERCISES:

1. Give equivalents to the following words and word combinations:

Piston engine, camshaft, wedge type combustion chamber, valve, wedge type com­bustion chamber, блок цилиндров, cylinder head, компоновка двигателя, camshaft lobe, штанга толкателя, internal combustion engine, коленчатый вал, clearance, engine configuration, opposed engine, роторный двигатель, рабочая смесь.

II. Translate the following sentences into Russian:

The internal combustion engine converts fuel into the energy that powers the au­tomobile.

A battery and electric starter get the engine starting but the car going.

It takes two complete revolutions of the crankshaft to complete the cycle.

During the exhaust stroke, the piston moves up again and forces the burned gases out of the cylinder and into the exhaust system. |

The location of the combustion chamber is the area between the top of the piston and the cylinder head.

The hemispherical combustion chamber is compact and allows high compression with a minimum of detonation.

The rotary engine burns as much as 20 % more fuel than the conventional one and is potentially a high polluter, but its small size allows the addition of emission-control parts more conveniently than does the piston engine.

Within this chamber of the rotary engine all four functions of a piston take place simultaneously in the three pockets that are formed between the rotor and the chamber wall.

The overhead camshaft arrangement has the advantage of eliminating the added weight of the rocker arms and push rods.