Engine (machine)
An engine is a device that converts various forms of energy into mechanical motion. This article outlines types, components, history, uses, and key distinctions between engines and motors.
An engine, often called a motor in everyday language, is a device or machine that converts stored or supplied energy into mechanical motion that can perform work. Engines vary widely in their design and operation but share the common purpose of producing controlled movement, whether rotary, reciprocating, or linear. The term covers both heat-driven devices and electrically driven machines.
Engines obtain energy from multiple sources. Chemical energy released by fuel such as gasoline, diesel or other hydrocarbons is common in internal combustion types. Electric energy from batteries or the grid powers electric motors, and thermal energy in external combustion setups or turbines can be supplied as heat. Broadly, any form of energy that can be converted into organized motion is a candidate for powering an engine; electricity is one of the most widely used forms today (electric).
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Characteristics and main parts
Despite variety, most engines have comparable elements: an energy source, a conversion mechanism that transforms that energy into mechanical force, and an output interface that transmits motion to tools, wheels, propellers, or generators. Typical components include bearings, shafts, pistons, cylinders, combustion chambers, rotors, stators, and control systems. Designs emphasize power density, efficiency, reliability, and maintainability.
- Piston or rotary mechanism: translates pressure or electromagnetic forces into rotation or reciprocation.
- Combustion or conversion chamber: where chemical or thermal processes generate force.
- Transmission interface: gears, clutches, couplings or shafts to deliver usable motion.
- Control and cooling systems: regulate operation and manage heat and emissions.
Types and examples
- Internal combustion engines: use fuel combustion inside cylinders (common in cars and light aircraft).
- External combustion engines: such as steam engines, where combustion heats a separate working fluid.
- Gas turbines: produce high-speed rotary motion from expanding gases, used in power generation and aircraft.
- Electric motors: convert electrical energy directly to motion, found in appliances, industry and electric vehicles.
- Rocket engines: produce thrust by ejecting high-speed propellant and operate on different principles than conventional ground engines.
Historically, engines evolved from simple water and windmills to steam-driven machines that powered industrialization, followed by internal combustion designs that enabled modern transportation. Later advances in materials, thermodynamics, and electrical engineering expanded performance and applications. Over time, environmental concerns and technological progress have driven shifts toward higher efficiency and electrification.
Engines serve essential roles across transportation, manufacturing, power generation, and tools. Distinctions often made in everyday use include "engine" for heat-based or chemical-powered systems and "motor" for electrically driven machines, though the terms can overlap. Important trade-offs in engine design include efficiency versus size, fuel type and availability, emissions, maintenance needs, and suitability for a given application. For further general reading on machine concepts see related material and sources on energy conversion at energy references. Additional practical and technical resources can be found via electrical, thermal and fuel topics.
History of the engine
The earliest engines may have been smoke turbines for opening large doors around the year 100 Herons. Also, conjectures about the handling of Egyptian priesthood with hot gases for moving huge doors are plausible.
Around 1670, Ferdinand Verbiest is said to have built an operable model of a steam carriage in the service of the Emperor of China. The operating principle was based on the Herons ball, as had been the case with earlier smoke turbines. The vehicle is described in Verbiest's writings compiled into Astronomia Europea in Latin in 1681, where he first used the term engine in its modern sense. However, authentic illustrations of this vehicle do not exist.
The technical development of today's engines began with the steam engine invented by Thomas Savery and Thomas Newcomen and further developed by James Watt in 1778.
The steam engine changed the economic and social structures of Europe and triggered the industrial revolution. There were not only stationary machines, but after the invention of the high-pressure steam engine by Richard Trevithick, also the locomobile (a mobile, partly self-propelled steam engine for driving threshing machines or for steam ploughing), steam locomotives, steam ships, steam tractors and steam road rollers.
In 1816, Robert Stirling invented the hot gas engine that was later named after him. He was looking for a machine without the explosive boiler.
One of the first usable internal combustion engines - a gas engine based on the two-stroke principle - was invented by Étienne Lenoir, improved in 1862 by Nikolaus August Otto by developing the four-stroke principle and later named after him. The Otto engine was initially too large and too heavy to be fitted in an automobile. This problem was solved almost simultaneously by Gottlieb Daimler and Carl Friedrich Benz.
Even after the invention of internal combustion engines, the steam engine was still a much-used power source - cheap coal or wood could be used as fuel. However, due to their better efficiency and the high energy density of the fuels, internal combustion engines have since come to the fore, converting the chemical energy of the fuels inside them into thermal energy and then into mechanical energy.
For the future, the aim is to change the energy source of mobile engines in order to counteract the scarcity and thus increase in price of fossil fuels. This often also reduces emission levels. A prerequisite for this are practicable storage options for non-fossil energy sources, especially for mobile use (accumulators, alternative fuels). Electric motors and hybrid drives are possible alternatives to replace or supplement the piston engine.
In all sizes, from toys to industrial plants, electric motors for direct current, alternating current and three-phase current are used (electrical machines). Many electric motors - especially those with permanent magnets - can also work as generators when driven mechanically.
Requirements for motors
Engines and other prime movers convert chemical, electrical or thermal energy into mechanical energy (work). From a modern point of view, they should
- have a high efficiency - i.e. use the fuel optimally and therefore with low consumption,
- cause few emissions or at least emit few pollutants,
- develop the highest possible performance with the lowest possible weight,
- have high operational reliability and a long service life
- and have other special properties depending on the application.
At the beginning of the engine construction stood - practically with each of the basic principles - the achievement of the necessary achievement. Other parameters of engines besides the power (consumption of electricity or fuel and mechanical power output) are the mass, the speed and the efficiency.
Questions and answers
Q: What is an engine?
A: An engine is a machine that converts energy into movement.
Q: What are the common forms of energy used in engines?
A: The common forms of energy used in engines are electricity, chemical (such as petrol or diesel), or heat.
Q: What is fuel?
A: Fuel is a chemical substance used to produce energy in engines.
Q: What is the purpose of an engine?
A: The purpose of an engine is to convert energy into usable movement.
Q: How does an engine work?
A: An engine works by converting energy into mechanical motion.
Q: Can any form of energy be used in an engine?
A: Yes, any form of energy can be used in an engine.
Q: What are some examples of fuels used in engines?
A: Some examples of fuels used in engines are petrol and diesel.
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AlegsaOnline.com Engine (machine) Leandro Alegsa
URL: https://en.alegsaonline.com/art/31440