A machine (or mechanical device) is a mechanical structure that uses power to apply forces and control movement to perform an intended action. Machines can be driven by animals and people, by natural forces such as wind and water, and by chemical, thermal, or electrical power, and include a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement. They can also include computers and sensors that monitor performance and plan movement, often called mechanical systems.
Renaissance natural philosophers identified six simple machines which were the elementary devices that put a load into motion, and calculated the ratio of output force to input force, known today as mechanical advantage.
Modern machines are complex systems that consist of structural elements, mechanisms and control components and include interfaces for convenient use. Examples include a wide range of vehicles, such as automobiles, boats and airplanes, appliances in the home and office, including computers, building air handling and water handling systems, as well as farm machinery, machine tools and factory automation systems and robots.
James Albert Bonsack’s cigarette rolling machine, invented in 1880 and patented in 1881
3 Simple machines
4 Mechanical systems
5 Power sources
6.1 Gears and gear trains
6.2 Cam and follower mechanisms
6.4 Planar mechanism
6.5 Spherical mechanism
6.6 Spatial mechanism
6.7 Flexure mechanisms
7 Machine elements
7.1 Structural components
9 Computing machines
10 Molecular machines
11.1 Mechanization and automation
12.1 Dynamics of machines
12.2 Kinematics of machines
13 Machine design
14 See also
16 Further reading
17 External links
The English word machine comes through Middle French from Latin machina, which in turn derives from the Greek (Doric μαχανά makhana, Ionic μηχανή mekhane “contrivance, machine, engine”, a derivation from μῆχος mekhos “means, expedient, remedy”). The word mechanical (Greek: μηχανικός) comes from the same Greek roots. A wider meaning of “fabric, structure” is found in classical Latin, but not in Greek usage. This meaning is found in late medieval French, and is adopted from the French into English in the mid-16th century.
In the 17th century, the word could also mean a scheme or plot, a meaning now expressed by the derived machination. The modern meaning develops out of specialized application of the term to stage engines used in theater and to military siege engines, both in the late 16th and early 17th centuries. The OED traces the formal, modern meaning to John Harris’ Lexicon Technicum (1704), which has:
Machine, or Engine, in Mechanicks, is whatsoever hath Force sufficient either to raise or stop the Motion of a Body… Simple Machines are commonly reckoned to be Six in Number, viz. the Ballance, Leaver, Pulley, Wheel, Wedge, and Screw… Compound Machines, or Engines, are innumerable.
The word engine used as a (near-)synonym both by Harris and in later language derives ultimately (via Old French) from Latin ingenium “ingenuity, an invention”.