Machine
A machine manages power to accomplish a task. Examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work. Asimple machine is a device that transforms the direction or magnitude of a force.
The word “machine” is derived from the Latin word machina,[1] which in turn derives from the Doric Greek μαχανά (machana), Ionic Greekμηχανή (mechane) “contrivance, machine, engine”[2] and that from μῆχος (mechos), “means, expedient, remedy”.[3]
The meaning of machine is traced by the Oxford English Dictionary[4] to an independently functioning structure and by Merriam-Webster Dictionary[5] to something that has been constructed. This includes human design into the meaning of machine.
Historically, a device required moving parts to classify as a machine; however, the advent of electronics technology has led to the development of devices without moving parts that many refer to as machines, such as a computer, radio, and television.[1]
Usage
[edit]Simple machines
The idea that a machine can be broken down into simple movable elements ledArchimedes to define the lever,pulley and screw as simple machines. By the time of the Renaissance this list increased to include the wheel and axle,wedge and inclined plane.
[edit]Engines
The Term Paper on Menstrual Meanings part 1
Menstrual Meanings (1) Throughout the history of humankind, such physiological aspect of womens existential mode as menstrual cycle, used to be traditionally surrounded with many controversies. There are different theories that strive to explain this from socio-political, psychoanalytical and philosophical perspectives. However, the majority of psychologists agree that societys popular attitudes ...
The word engine derives from “ingenuity” and originally referred to contrivances that may or may not be physical devices.
An automobile engine is called an internal combustion engine because it burns fuel (an exothermic chemical reaction) inside a cylinder and uses the expanding gases to drive a piston. A jet engine uses a compressor to compress air which is burned with fuel so that it expands through a nozzle to provide thrust to an aircraft, and so is also an “internal combustion engine.” [6]
[edit]Computing machines
Computers store and manipulate the flow of electrons, with patterns in this storage and flow being interpreted as information manipulation. See State machine and Turing machine.
Charles Babbage designed various machines to tabulate logarithms and other functions in 1837. His Difference engine is the first mechanical calculator. This machine is considered to be the forerunner of the modern computer though none of them were built in his lifetime.
[edit]Molecular machines
Study of the molecules and proteins that are the basis of biological functions has led to the concept of a molecular machine. For example, current models of the operation of the kinesin molecule that transports vesicles inside the cell as well as the myocin molecule that operates against actin to cause muscle contraction; these molecules control movement in response to chemical stimuli.
Researchers in nano-technology are working to construct molecules that perform movement in response to a specific stimulus. In contrast to molecules such as kinesin and myosin, these nano-machines or molecular machines are constructions like traditional machines that are designed to perform in a task.
[edit]History
Perhaps the first example of a human made device designed to manage power is the hand axe, made by chipping flint to form a wedge. A wedge is a simple machine that transforms lateral force and movement of the tool into a transverse splitting force and movement of the workpiece.
The Essay on Mechanics Of Machines Lab Report
Introduction The motion of assemblies is determined by the configuration of links and joints. Using the configurations the operation of rotational and sliding joints are examined and observed. This kind of mechanism is very commonplace in machines. Machines are made up of a number of parts and relative motion between the various parts permits the working of the machine. As the crank is rotated the ...
The lever is perhaps the first machine to be analysed mathematically; Archimedes provided the first known description of the principle of the lever.
[edit]Machine elements
Machines are assembled from components called machine elements. These elements consist ofmechanisms that control movement in various ways such as gear trains, transistor switches, beltor chain drives, linkages, cam and follower systems, brakes and clutches, and structural components such as frame members and fasteners.
Modern machines include sensors, actuators and computer controllers. The shape, texture and color of covers provide a styling and operational interface between the mechanical components of a machine and its users.
[edit]Mechanisms
Assemblies within a machine that control movement are often called “mechanisms.” [7][8]Mechanisms are generally classified as gears and gear trains, cam and follower mechanisms, andlinkages, though there are other special mechanisms such as clamping linkages, indexing mechanisms and friction devices such as brakes and clutches.
For more details on mechanical machines see Machine (mechanical) and Mechanical systems.
[edit]Controllers
Controllers combine sensors, logic, and actuators to maintain the performance of components of a machine. Perhaps the best known is theflyball governor for a steam engine. Examples of these devices range from a thermostat that as temperature rises opens a valve to cooling water to speed controllers such the cruise control system in an automobile. The programmable logic controller replaced relays and specialized control mechanisms with a programmable computer. Servomotors that accurately position a shaft in response to an electrical command are the actuators that make robotic systems possible.
[edit]Machine design
Machine design plays an important role in all three of the major phases of a product lifecycle:
1. invention, which involves the identification of a need, development of requirements, concept generation, prototype development, manufacturing, and verification testing;
The Essay on The Role Of History As A Political Mechanism For Social Control
In both novels, Brave New World by Arthur Huxley and 1984 by George Orwell, the role of History is essential. History is an essential component to understand the present circumstances. The use of History is not to repeat mistakes from the past in the future. History plays an important role in both novels, however they are handled differently. In the Novel Brave New World by Arthur Miller, History ...
2. performance engineering involves enhancing manufacturing efficiency, reducing service and maintenance demands, adding features and improving effectiveness, and validation testing;
3. recycle is the decommissioning and disposal phase and includes recovery and reuse of materials and components.
