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 restricted to devices having rigid moving parts that perform or assist in performing some work. Machines normally require some energy source ("input") and always accomplish some sort of work ("output"). Devices with no rigid moving parts are commonly considered tools, or simply devices, not machines. People have used mechanisms to amplify their abilities since before written records were available. Generally these devices decrease the amount of force required to do a given amount of work, alter the direction of the force, 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. Hydraulics 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. [edit] Types of machines and other devices Types of machines and other devices Simple machines Inclined plane, Wheel and axle, Lever, Pulley, Wedge, Screw Mechanical 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 Compressors and 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, Wankel engine, Jet engine, Rocket, gas turbine Linkages Pantograph,Peaucellier-Lipkin Turbine Gas turbine, Jet engine, Steam turbine, Water turbine, Wind generator, Windmill (Air turbine) Airfoil Sail, Wing, Rudder, Flap, Propeller Electronic machines Computing machines Calculator, Computer, Analog computer Electronics Transistor, Diode, Capacitor, Resistor, Inductor Biological machines Virus, Bacterium, Cell (biology), Plant and animal, DNA computers, Human being Miscellaneous Robot, Vending machine, Wind tunnel [edit] 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.  v ? d ? e Major fields of technology Applied science Artificial intelligence · Ceramic engineering · Computing technology · Electronics · Energy · Energy storage · Engineering physics · Environmental technology · Materials science & engineering · Microtechnology · Nanotechnology · Nuclear technology · Optical engineering · Zoography Information and communication Communication · Graphics · Music technology · Speech recognition · Visual technology Industry Construction · Financial engineering · Manufacturing · Machinery · Mining · Business Informatics Military Bombs · Guns and Ammunition · Military technology and equipment · Naval engineering Domestic Educational technology · Domestic appliances · Domestic technology · Food technology Engineering Aerospace · Agricultural · Architectural · Biological · Biochemical · Biomedical · Ceramic · Chemical · Civil · Computer · Construction · Cryogenic · Electrical · Electronic · Environmental · Food · Industrial · Materials · Mechanical · Mechatronics · Metallurgical · Mining · Naval · Nuclear · Petroleum · Software · Structural · Systems · Textile · Tissue · Transport Health and safety Biomedical engineering · Bioinformatics · Biotechnology · Cheminformatics · Fire protection engineering · Health technologies · Pharmaceuticals · Safety engineering · Sanitary engineering Transport Aerospace · Aerospace engineering · Marine engineering · Motor vehicles · Space technology