reciprocating engine

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reciprocating engine

[ri′sip·rə‚kād·iŋ ′en·jən]
(mechanical engineering)

Reciprocating Engine


a device in which a piston performs the basic function of transforming the energy of a working fluid. As the piston moves within a cylinder, there is a change in the volume of the chamber formed; as this occurs, various parameters of the working fluid, such as pressure and temperature, also change. During operation of a reciprocating engine, the energy of the working fluid may be decreased, as in a gasoline engine, or increased, as in a pump or compressor. The intake and exhaust of the working fluid in the cylinder are regulated by a distribution or timing mechanism using simple valves or slide valves or by the piston itself, as in a two-cycle engine.

The reciprocating engine is characterized by cyclic reoccurrence and intermittence of operation. In most reciprocating engines the piston is connected with the crankshaft by a crank gear, by means of which the reciprocating motion of the piston is converted into the rotary motion of the shaft, or vice versa. Because of the cyclic reoccurrence of operation and the presence of a crank gear, reciprocating engines do not operate at speeds as high as those achieved by rotodynamic machines; the former have a greater specific mass and greater factional losses. Reciprocating engines without connecting rods are now being used, in which reciprocating motion is converted to rotary motion by a powered mechanism without connecting rods. Rotary-piston engines, such as the Wankel engine, are also being used. In a steam pump, the reciprocating motion of the piston of a reciprocating engine is used directly to drive the pump’s piston; in a motor-driven compressor, the engine and compressor are combined in a single multicylinder unit. The use of a plunger as a piston in reciprocating engines makes it possible to operate pumps at higher pressures. Reciprocating engines are simple to operate, economical, reliable, and have a long operating life.


reciprocating engine

An engine that converts the chemical energy in the fuel plus air into mechanical energy by providing reciprocating movement to the pistons. This movement is further converted into rotary motion by the connecting rods and crankshaft. A reciprocating engine is usually a four-stroke engine. See four-stroke cycle.
References in periodicals archive ?
As a technology leader in the distributed power space, GE continues to invest heavily in technology and companies that provide excellent performance, output and efficiency advancements in the reciprocating engines space," said Karl Wetzlmayer, general manager-reciprocating engines for GE Power & Water's Distributed Power business.
They chose not to connect the reciprocating engine to the wheels in the style of old-fashioned steamers, Prahl says, because railroad managements want to keep the diesel-electric drive.
Burns & McDonnell has designed and built a majority of the utility-scale reciprocating engine projects in the country as more and more utilities turn to reciprocating engines to balance their power needs.
Rolls-Royce sees RRPS as a valuable addition to its Marine and Industrial Power Systems division, operating in long-term growth markets with a world class technology, the buyer's CEO John Rishton said, adding that the acquired business brings scale and capability to his company's reciprocating engines portfolio.
Secretary of Energy Bill Richardson has awarded $15 million over five years to three industrial partners to research, develop and test advanced natural gas reciprocating engines.
According to F&S, many end users of portable generators in commercial and telecom segments might opt for FC technology, which "[has] long-term attraction and [is] conceptually superior to reciprocating engine technology.
KGRA Energy hE a developer of waste heat recovery power generation projects, will develop a pioneering waste heat recovery project to harness reciprocating engine exhaust heat.
Tenders are invited for Reciprocating engine power plant electrical testing.
The prime mover, whether it is a reciprocating engine or a gas turbine; jacket water cooling; gas compressors, either reciprocating or centrifugal; and relief valves including compressor, piping pressure relief, blowdown, and station ESD systems.
The A-Plus has been used on reciprocating engine, turbine, and boiler applications considered low N[O.
pulled a 1,750-hp Electro-Motive diesel from a 1950s switcher and replaced it with a 6-liter Daewoo reciprocating engine and 55,000 lbs.