|
|
| Line 1: |
Line 1: |
| − | {{Copyedited}}{{Images OK}}{{Submitted}}{{Approved}}{{Paid}}
| |
| − | :''This article is about devices that perform tasks.''
| |
| − | [[Image:USDA windmills.jpg|right|thumb|Wind turbines]]
| |
| − | The scientific definition of a '''machine''' 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 [[mechanical work|work]] ("output"). Devices with no rigid moving parts are commonly considered [[tool]]s, or simply [[device]]s, 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 (physics)|motion]] or energy into another.
| |
| − |
| |
| − | Modern power tools, [[automation|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 [[engine]]s.
| |
| − |
| |
| − | [[Hydraulic]]s devices may also be used to support [[Industry|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 (ocean)|marine]] industries, [[Aeronautics|aeronautical]] industries, [[construction equipment]] industries, [[Engineering vehicle|and earthmoving]] equipment industries.
| |
| − |
| |
| − | == Mechanical advantage and efficiency ==
| |
| − |
| |
| − | 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 percent efficient.
| |
| − |
| |
| − | == Types of machines and other devices ==
| |
| − |
| |
| − | {| class="wikitable"
| |
| − | |+'''Types of machines and other devices'''
| |
| − | | rowspan="1" | [[Simple machine]]s || [[Inclined plane]], [[Wheel and axle]], [[Lever]], [[Pulley]], [[Wedge (mechanics)|Wedge]], [[Screw (simple machine)|Screw]] <!-- 'Simple machine' has a rather precise meaning - and that is the complete list - don't add to it! —>
| |
| − | |-
| |
| − | | rowspan="1" | Mechanical components || [[Gear]], [[Rope]], [[Spring (device)|Spring]], [[Wheel]], [[Axle]], [[Bearing (mechanical)|Bearings]], [[Belt (mechanical)|Belts]], [[Seal (mechanical)|Seals]], [[Roller chain]]s, [[Link chain]]s, [[Rack and pinion]], [[Fastener]], [[Key (lock)|Key]]
| |
| − | |-
| |
| − | | rowspan="1" | [[Clock]] || [[Atomic clock]], [[Chronometer]], [[Pendulum clock]], [[Quartz clock]]
| |
| − | |-
| |
| − | | rowspan="1" | [[Gas compressor|Compressors]] and [[Pump]]s || [[Archimedes screw]], [[Eductor-jet pump]], [[Hydraulic ram]], Pump, [[Tuyau]], [[Vacuum pump]]
| |
| − | |-
| |
| − | | rowspan="2" | [[Heat engine]]s || [[External combustion engine]]s || [[Steam engine]], [[Stirling engine]]
| |
| − | |-
| |
| − | | [[Internal combustion engine]]s || [[Reciprocating engine]], [[Wankel engine]], [[Jet engine]], [[Rocket]], [[gas turbine]]
| |
| − | |-
| |
| − | | rowspan="1" | [[Linkage (mechanical)|Linkages]] || [[Pantograph]], [[Peaucellier-Lipkin linkage|Peaucellier-Lipkin]]
| |
| − | |-
| |
| − | | rowspan="1" | [[Turbine]] || [[Gas turbine]], Jet engine, [[Steam turbine]], [[Water turbine]], [[Wind generator]], [[Windmill]] (Air turbine)
| |
| − | |-
| |
| − | | rowspan="1" | [[Airfoil]] || [[Sail]], [[Wing]], [[Rudder]], [[Flap]], [[Propeller]]
| |
| − | |-
| |
| − | | rowspan="2" | Electronic machines || Computing machines || [[Calculator]], [[Computer]], [[Analog computer]]
| |
| − | |-
| |
| − | | [[Electronics]] || [[Transistor]], [[Diode]], [[Capacitor]], [[Resistor]], [[Inductor]]
| |
| − | |-
| |
| − | | rowspan="1" | [[Biology|Biological machines]] || [[Virus]], [[Bacterium]], [[Cell (biology)]], [[Plant]] and [[animal]], [[DNA computing|DNA computers]], [[Human being]]
| |
| − | |-
| |
| − | | rowspan="1" | Miscellaneous || [[Robot]], [[Vending machine]], [[Wind tunnel]]
| |
| − | |-
| |
| − | |}
| |
| − |
| |
| − | ==References==
| |
| − | * Boothroyd, Geoffrey and Winston A. Knight. 2005. ''Fundamentals of Machining and Machine Tools, Third Edition (Mechanical Engineering (Marcell Dekker))''. Boca Raton, FL: CRC. ISBN 1574446592
| |
| − | * Myszka, David H. 1998. ''Machines and Mechanisms: Applied Kinematic Analysis''. Upper Saddle River, NJ: Prentice Hall. ISBN 0135979153
| |
| − | * Oberg, Erik, Franklin D. Jones, Holbrook L. Horton, and Henry H. Ryffel. 2000. ''Machinery's Handbook''. New York, NY: Industrial Press Inc. ISBN 0-8311-2635-3
| |
| − |
| |
| − |
| |
| − | ----
| |
| − | {{Technology}}
| |
| − |
| |
| − | [[Category:Physical sciences]]
| |
| − | [[Category:Mechanical engineering]]
| |
| − | [[Category:Electrical engineering]]
| |
| − |
| |
| − | {{credit|161104907}}
| |
