Machine

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This article is about devices that perform tasks. For other uses, see Machine (disambiguation). Wind turbines

The scientific definition of a "machine" (derived from the Latin machina) is any device that transmits or modifies energy. In common usage, the meaning is that of devices having parts that perform or assist in performing any type of work (cf Concise Oxford Dictionary). Machines normally require some energy source ("input") and always accomplish some sort of work ("output"). Devices with no rigid moving parts can be considered tools.

A machine is anything that makes work easier.

People have used mechanisms to, or transform one form of motion or energy into another.

The mechanical advantage of a simple machine is the ratio between the force it exerts on the load and the input force applied. This does not entirely describe the machine's performance, as force is required to overcome friction as well. The mechanical efficiency of a machine is the ratio of the actual mechanical advantage (AMA) to the ideal mechanical advantage (IMA). Functioning physical machines are always less than 100% efficient.

Modern power tools, automated machine tools, and human-operated power machinery are tools that are also machines. Machines used to transform heat or other energy into mechanical energy are known as engines.

Compound machines are composed of more elementary machines called simple machines, such as the wedge and the pulley. Machines are considered simple machines if they perform their action in one movement. These devices may also be used to support industrial applications, although devices entirely lacking rigid moving parts are not commonly considered machines. Hydraulics are widely used in heavy equipment industries, automobile industries, marine industries, aeronautical industries, construction equipment industries, and earthmoving equipment industries.

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Types of machines and other devices

Types of machines and other devices Simple machines Inclined plane, Wheel and axle, Lever, Pulley, Wedge, ScrewMechanical components Gear, Rope, Spring, Wheel, Axle, Bearings, Belts, Seals, Roller chains, Link chains, Rack and pinion, Fastener, Key Clock Atomic clock, Chronometer, Pendulum clock, Quartz clock Compressorsand Pumps Archimedes screw, Eductor-jet pump, Hydraulic ram, Pump, Tuyau, Vacuum pump Heat engines External combustion engines Steam engine, Stirling engine Internal combustion engines Reciprocating engine Linkages Pantograph, Peaucellier-Lipkin Turbine Gas turbine, Jet engine, Steam turbine, Water turbine, Wind generator, Windmill(Air turbine) Aerofoil Sail, Wing, Rudder, Flap, PropellerElectronic machines Computing machines Calculator, Computer, Analog computer Electronics Transistor, Diode, Capacitor, Resistor, Inductor Biological machines Virus, Bacterium, Cell (biology), Plantand animal, DNA computers, Human beingMiscellaneous Robot, Vending machine, Wind tunnel, Check weighing machines

References

Oberg, Erik; Franklin D. Jones, Holbrook L. Horton, and Henry H. Ryffel (2000). in ed. Christopher J. McCauley, Riccardo Heald, and Muhammed Iqbal Hussain: Machinery's Handbook, 26th edition, New York: Industrial Press Inc.. ISBN 0-8311-2635-3.