Engine

an engine is a prime mover, which moves or propels mechanical devices. It changes forms of energy, like thermal or electricity, into mechanical energy and/or. Work over, which is for its part movement - with engines usually rotation -. To subdivide leavesitself the category in the steam engine, electric motor and combustion engine.

The engine construction is the development and the building from aggregates to the drive for work machines, driving and airplanes. From technical view it is a section of mechanical engineering, from economic view it belongs to metal - or machine industry.

Before the invention of the automobiles the steam engine was the usually-used engine, due to its better efficiency and the high energy store density of the fuels is since then combustion engines into the foregroundstepped, which convert fossil fuel energy only into heat energy and then into mechanical energy. Here distinctive between the very wide-spread lifting cylinder engines (petrol or Diesel process, four-stroke engine, two-stroke engine) and rotary piston motors (wankel engine). Today regulate into thatAutomobiles own motor controls the burn procedures.

For the future one aims at a change of the energy source of mobile engines, in order to meet the shortage and with it raising the price of from fossil fuel to. Pleasant side effect is thereby the reduction of the emission values. A condition for this are again practicable conditions of stored energy quantities and their carryable weights. Alternative ones represent here for example electric motors, hybrid drives or hydrogen drives . Substantial expenditure becomes z. B. in the area of the development of gas cells floated.

In all sizes, of toys to Industrial plants, find electric motors for direct current and alternating current use (electrical machines). Many electric motors - special such with permanent magnets - can work also as generators, if they are mechanically propelled.

For generators, electric motors as well as transformers in the Kilo andMega Watt - range one researches strengthened at the working maturity of superconductors.

Magnetic levitation transport systems are a well-known application of the linear motors.

Table of contents

further kindsof engines

history

from historical view stood the 1712by Thomas Newcomen invented and 1778 of James Watt crucially improved steam engine at the beginning of the engine development. The steam engine changed the economic and social structures of Europe and released the industrielle revolution .

1678 are it already a steam car for the emperorfrom China gave (Ferdinand beast) and around 100 Herons steam turbine for opening large gates. Also assumptions are plausible to handling Egyptian priest shank with hot gases for moving enormous doors.

requirements of engines

engines and others Prime movers convert chemical, electrical or thermal energy into mechanical energy (work). They are to possess a high

  1. efficiency from modern view - i.e. the fuel optimally and therefore with small consumption use,
  2. few emissions cause or at least few Pollutants discharge,
  3. as high an achievement as possible with small weight develop,
  4. high working reliability and life span exhibit
  5. and depending upon application further special characteristics possess.

At the beginning of the building of engines - practically with each the basic principles - the achievement of the necessary achievement stood. Further characteristics of engines are apart from the achievement (initially or power output) still the mass, the rotating speed and the efficiency.

kinds of engines

electric motor

the most frequently assigned kind of enginesis the electric motor. Drives of the most diverse size and achievement are in practically all aggregates - of miniaturized servo - and stepping motors over devices for household, office, climate and car up to industriellen large machines. The advancement finds hereless in the building of engines than in the optimization of its applications instead of.

steam engine

at the beginning of the industrialization was prevailing the steam engine.

combustion engines

with the invention of the automobile to end 19. Century became in mechanical engineeringoften also combustion engines assigned. They convert the energy of fossil fuels into thermodynamic cycles to mechanical work . Usually the expansion of the incineration gases (“explosion “) is converted into a stroke and a this into a rotation, which for its part Kraft forthe drive supplies.

The efficiency of combustion engines is generally worse than the other engine principles. Therefore still numerous possibilities of the improvement in them despite 150 years development (design, fuel, control etc.) are.

Combustion engines are mechanical constructions, the fresh air with a burn mediummix like gasoline , gas , Diesel or fuel oil and to burning bring. The burn is only possible, since a burn promoter the oxygen and an inflammable medium are gaseously mixed, consolidated and ignited such as gas, gasoline, Diesel or fuel oil. Thosefrom the chemical burn clock won energy - difference is converted mechanically into driving power.

optimization of the combustion engines

for the controlling of the fresh air runs in the standard engines the valve gear or rotary valve with the clock rates synchronously. Serious change to the acceleratedPromotion of the fresh air was reached by the use of the turbocharger, which from racing originates. This not least because of the substantially better efficiency of in such a way equipped engines. Regarding the promotion of the inflammable medium such as gasoline etc. that hasEngine construction an improvement of the gasoline supply regarding the injection nozzles experience. These injection nozzles are electrically headed for and thus into the modern electronic controlling of the engines integrable.

self fuze (diesel engine)

knows the explosion or burn of a fuel without helping means- only by the high compression of the air fuel mixture - take place, concerns a self fuze. Improvements it gave in the modification of the combustion chambers, to pistons of the injection nozzles and the feed pumps. The glow plugs of the Dieselmotores and/or. Multifuel engine are only aidsto the cold weather starting. Here no substantial innovation gave itself except modifications of the glow plugs.

foreign fuze (petrol engine)

is not as high the Verdichtug of the engine as with the self fuze, then it needs spark plugs, which were developed by Bosch. Improvementsit gave the choice of materials of the spark plugs ( platinum) in that and by means of the complete assumption by the electronic engine sensor technology and the control.

combustion engine types

as piston engines (see also prime mover) it divided into:

Among first the well-known designs of two-stroke engine

  • rank - particularly for mopeds, the earlier DKW and, still well-known, the “Trabi “. In the auto+'s building it made place however
  • to a large extent for the petrol engine, the classical four-stroke engine.
  • Diesel engine,as well as variants as
  • steam engine and pneumatic motor, to the further
  • the wankel engine. It was 1957 to approx. 1980 a piece of parade of the modern building of engines and combine four and secondary act principle. By few mobile parts it is disturbance and vibration-poor. In addition hasit a small size, combines thus high achievement with low weight and space requirement.
    • The combustion chamber with unfavorable relationship from surface to volumes delivers however much warmth unused to the housing and leaves somewhat unburned mixture, with firstInto the exhaust went to type rows. One can work against the worse efficiency than with the petrol engine by point of two ignition. The initially high wear of the sealings was a challenge to the technical designers - just like the higher number of revolutions. It requires highMaterial quality and exact manufacturing. The hurdles were successfully taken. But hopes of the 1970er and 1980er years on a crucial turn in the building of wankel engines were not expected fulfilled as.

However still

  • some development potential is granted to the stirling engine. It is onefurther piston engine for the utilization of thermal energy, which it converts similarly the steam engine by a cyclic process.

The today's combustion engines are optimized in their enterprise mostly by electronic motor control.

development, future

this group of engines is the most frequently assigned, in particularas gasoline and diesel engine. It makes the majority for that vehicle - drives out for car and truck, diesel locomotive, tank etc., small airplanes and Motorsegler, flight - and motorboats, yachts, Rasenmäher and many further applications.

The combustion engineis mechanical an advancement of the steam engine and has, from today's viewpoint still over decades, best conditions, to be further optimized in consumption, efficiency and in the material use of the engine. The optimization is done partially via other fuels such as hydrogen,the nearly pure water vapour as exhaust gases have, by electrolytic dissociation (electro-chemical splitting) of water in hydrogen and oxygen again at new fuel and the fuel promoter (oxygen) to arrive, as well as by combinatorial energy uses with hybrid concepts.

other types

By many other principles of engines in the future also in the traffic on an increasing change of the energy sources will have to be counted to reduce above all in order the emissions. Hope carriers are beside the electric road vehicle above all the hybrid drive, the use that Brake energy and the gas cell. On the latter one works certainly for over 100 years, in order to come to production stage.

steam engines

the steam engine is the “Urmotor” of the industrialization of the last centuries. It is a Konstrukt, which of Thomas Newcomen was invented and continued to develop by James Watt. She works with hot water vapour under pressure. The produced water vapour converted into a cylinder housing with pistons introduces and there by means of a crank gear into mechanically usable energy. Becomes howwith the combustion engine a linear movement over a crank gear into a rotation converted.

function mode

using a fire boiler, in which with a coal fire the water on boiling temperature is more highly heated up or, produces itself the water heated up for expanding steam.

This steam is supplied by way of a mechanical control unit by the crank gear of the steam engine. The control unit causes that the Dampfzylinder (in that the piston runs) of the crank gear receives steam again only if the expanded steam of the previous stroke clock escaped as far as possible is.

movement conversion

the linear movement of the piston in the expanding cylinder space, into which the water vapour was let in before, is converted by a connecting rod at the cranking or stroke tap into a rotating motion. This procedure repeats itself continuously. Which the locomotive outthe chimney dismisses, is mixed the discharged steam of the piston cylinders, with the smoke exhaust gases of the firing.

other

you were the first usable prime movers of the technology (Watt of 1778, Stevenson around 1830) and work with expanded water vapour. Its thrust forceby the steam piston one takes up, which can be moved as a rule inside a cylinder (Dampfzylinder) under good sealing back and forth. Already around 1850 there were several kinds of this piston engine:

development, future

the steam engine is ofBurning us engine replaced and can be regarded from today's viewpoint energetically as outdated. It has a too low efficiency and has thus no more future. If the burning us warmth is available occurring naturally as in Iceland (Geothermie), then becomesone in place of a stationary steam engine rather the steam turbine uses, also today its place has in each coal-fired power station.


steam turbine

you is the modern version of the thermal engine and uses the steam strength with higher efficiency. Their pressure drives one Turbine on, whose turn has in principle a calmer run than the back and forth of a steam piston. The torque process is flatter therefore, i.e., it works evenly.

development, future

in power stations evaporate behind the turbine condensedto work, over against a vacuum and not against the atmospheric air pressure. Thus the efficiency increases, according to the relationship atmospheric pressure to positive pressure.

gas turbines

turbines with incineration gases belong like the steam turbine to the “thermal fluid suppl. IE machines ",but into the group of the internal combustion engines. As fluid-flow machines they both are considered.

Each gas turbine has a compressor (compressor), a combustion chamber and a turbine, which are mechanically coupled usually over the same wave with the compressor. The air compressed by the compressor becomesin the combustion chamber at temperatures to 1500°C with the injected fuel burned. The incineration gases leaking out with high speed drive the turbine on (with rockets it is void). The turbine extracts at least that flow energy, which is necessary for the drive of the compressor from them.The larger remainder stands than usable energy for order - either for higher rotating speed of the turbine (power station, helicopter) or than recoil.

efficiency and applications

the hotter the gases are, the more highly are the efficiency of gas turbines. Hereinand in the ideal form of the turbine blades large growth prospects of the engine construction lie. Substantially here is the thermal maximum stress of shovels and shroud.

Applications in aviation are given, approximately by the very good power-to-weight ratio of the gas turbines as engine for helicopters or turbo-prop. - Airplanes. In addition, the kinetic energy of the gaseous fuels is usable for recoil - drive of airplanes. With jets so-called become. Jet engines assigned, whose principle corresponds to the gas turbine to a large extent: after the three construction units a nozzle follows the pure guest turbine,by those the exhaust gas jet withdraws. The turbine receives only so much energy (rotating speed), as it needs for the drive of the compressor.

Applications in the navigation: here it depends less on favorable relationship an achievement mass, than on small fuel consumption,and today also on a smaller contamination of the seas. One accommodates the marine engine in the hull , where one can take also precautions against vibrations or other disturbances. Also for air cushion vehicles the gas turbine is often selected.

Application in power stations two designsby gas turbines are differentiated.

  • Heavy design (Heavy Frame): the turbines have achievements of over 50 MW (up to some hundred MW) and are meant for stationary continuous operation in large power stations.
  • Easy design: Aircraft turbine derivatives or aircraft of derivatives have achievements of100 KW to 40 MW and are constructionally similar to the aircraft turbines. With the employment in industrial power stations these turbines are often a component of a force heat coupling and/or. a GuD - plant (Gas-und steam power plant). Favorable they are also for efficient emergency power generators, approximately for hospitals,because they for full starting only few minutes need.


to rocket propulsion

see also airplane - and rocket technology.

electric motors

electric motors are energy converters, which convert electric current in rotation or linear movement. The engine construction works with standardizedParts (DIN), which the production of engines standardizes. This applies at least to Germany. European electric motor products are subject to another standard, the CEE - standard.

There are electric motors for direct current, alternating current and three-phase alternating current. They find particularly with industrial plants and for electrical machines use - also with toy and of the PC - exhaust likewise in household appliances. The engine construction forces its successes by miniaturization and working reliability.

Newer developments concern the industrial use of superconductors, on which one works intensively.It will concern the building of transformers apart from increases in output in the building of engines also.

Many electric motors, particularly such with permanent magnets, can work also “in reverse” as generators, i.e. produce electricity by their mechanical drive.

alternative of drive systems

Addition of the classical autoengines

for other purposes are among other things intended:

alternative of fuels

by the oil - scarceness which can be foreseen becomes also onnew fuels instead of gasoline, kerosene, heavy and diesel oil worked. They place the engine construction before high challenges, because the burn procedures are to be modelled again:

[] If improvements

on petrol and diesel engine work on

around the demand after fewer environmental damage and energy consumption to correspond, the diesel engine must become still substantially more cleanly, and the petrol engine clearly more economically. A just as large effect would leave itself certainly already by more energy-savingDriving fashion of many drivers obtain.

The technical aspects in addition are to a large extent clear, but must accompany a consciousness-shaping with it. From this lack the three-litre car, for one decade and technical-economically long feasiblly, publicised itself still hardly at the market interspersed. New one Possibilities result in the increasing markets in India and China.

summary: today's tendencies in the engine construction

with passenger car drives are medium-term political beside the development and economical of ecological application those - social basic conditions with crucial. US - Legislationabove all a strict limitation of the pollutant emissions demands and worries less about the climatic protection. Evenly because of this however Europe wants to thus dam also the CO2 - emissions, the fuel consumption, further.

There the combustion engine in the foreseeable future dominating propulsion principlewill remain, applies:

  • Consumption-favorable in principle diesel engine must its emissions of nitrogen oxide - and particles (v.a. Soot) reduce, but while maintaining its advantage in consumption.
  • For the petrol engine technical concepts are to be established, which continue to lower its consumption.
  • Ina transition period to alternative propulsion principles also hybrid engines must be used.

see also

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application

Wiktionary: Engine - word origin, synonyms and translations
 

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