Е. С. Закирова, П. А. Красавин Английский язык для технических вузов
A recipro- cating engine has one or more cylinders in which pistons reciprocate back and forth. The
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A recipro- cating engine has one or more cylinders in which pistons reciprocate back and forth. The combustion chamber is located in the closed end of each cylinder. Power is delivered to a rotating output crankshaft by mechanical linkage with the pistons. Reciprocating engines are classified on the base of position and number of cylinders. These are single-cylinder engine, in-line engine, V-type engine, opposed-cylinder engine, W-type engine, opposed-piston engine, and radial engine. A single-cylinder engine has one cylinder and piston connected to the crankshaft. In-Line engine cylinders are positioned in a straight line, one behind the other along the length of the crankshaft. In V-type engine, two banks of cylinders are at an angle with each other along a single crankshaft, allowing for a shorter engine block. Opposed-cylinder engine has two banks of cylinders opposite to each other on a single crankshaft. These engines are 219 often called flat engines. Engines of two different cylinder arrangements have been classified as W-type engines in the technical literature. An opposed-pis- ton engine has two pistons in each cylinder with the combustion chamber in the centre between the pistons. Radial engines are engines with pistons posi- tioned in a circular plane around a circular crankshaft. The connecting rods of the pistons are connected to a master rod, which in turn, is connected to the crankshaft. A rotary engine is made of a large non-concentric rotor with a built-in gearwheel, moving around a stationary block (stator). The moving combus- tion chambers are formed by the corners of the rotor sliding against the inner surface of the non-rotating block (housing). A number of experimental engines have been tested using this concept, but the only design that has ever become common in an automobile is the Wankel engine which has one, two, and three rotors. Вy method of fuel input, spark-ignition engines are divided into four types: carburetted engines in which air and fuel are mixed to facilitate the combustion process; multipoint port fuel injection engines in which one or more injectors at each cylinder intake; throttle body fuel injection engines in which injectors upstream in intake manifold; gasoline direct injection engines in which injec- tors are mounted in combustion chambers with injection directly into cylinders. By method of fuel input, compression-ignition engines are divided into three types: direct injection engines in which fuel is injected into the main combustion chamber; indirect injection engines in which fuel is injected into the secondary combustion chamber; homogeneous charge compression igni- tion engines in which well-mixed fuel and oxidizer (typically, air) are com- pressed to the point of auto-ignition. Besides, different kinds of fuel are used in engines: diesel oil, motor oil, naphta; kerosene or benzol-oil mixtures; gas, natural gas methane; alcohol- ethyl, methyl; dual fuel. There are several engines that use a combination of two or more fuels. Several or all of these classifications can be used at the same time to iden- tify a given engine. Thus, a modern engine might be called a reciprocating, spark-ignition, four-stroke cycle, I-head, water-cooled, gasoline, multipoint port fuel injection automobile engine. жүктеу/скачать 4,38 Mb. Достарыңызбен бөлісу:
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