Machine
From Halbeeg, the open encyclopedia · Af-Soomaali
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A machine is a device made up of interconnected parts that converts energy in form or application to perform work. The work may involve lifting, turning, cutting, moving, or processing information. Machines do not create new energy; they only transfer or convert it to another form, with part of the energy lost to friction and heat.
The definition of a machine is broad. It encompasses simple tools such as the lever and pulley, as well as complex systems like engines, aircraft, and computers. Engineering divides machines into parts: the prime mover (for example, an engine), the components that transmit motion (gears, shafts, chains), and the working parts.
Simple machines
Engineering tradition identifies six simple machines as fundamental to all other machines: the lever, gear and axle, pulley, inclined plane, wedge, and screw. Each converts force or direction. The lever, for example, can produce greater force to move a load, but the distance moved is reduced. This follows the law of conservation of work: if force is increased, distance is decreased.
Brief history
Simple machines have been used for thousands of years in construction, agriculture, and shipbuilding. Greek philosophers, notably Archimedes, wrote about the principles of levers and pulleys. In later centuries, water- and wind-powered machines were developed. In the 18th and 19th centuries, the steam engine and manufacturing made machines central to production; in the 20th century, electricity, the internal combustion engine, and electronic control vastly expanded their use.
Efficiency and energy
Machine efficiency is the ratio of useful work output to energy input. It never reaches one hundred percent, since friction converts part of the energy to heat. Machine design must account for force, material strength, maintenance, and cost of production.
Modern machines
Today's machines commonly integrate digital, electrical, and software components. Factory robots, CNC machines, and automated equipment exemplify the combination of engineering and data control. The term 'machine' is also used in extended sense in mathematics and computer science, as in 'Turing machine', a theoretical model for describing computation.