A centrifugal governor is a specific type of governor that controls the speed of an engine by regulating the amount of fuel (or working fluid) admitted, so as to maintain a near constant speed whatever the load or fuel supply conditions. A governor is a device used to measure and regulate the Speed of a Machine, such as an Engine. Speed is the rate of motion, or equivalently the rate of change in position often expressed as Distance d traveled per unit of An engine is a mechanical device that produces some form of output from a given input Fuel is any material that is burned or altered in order to obtain energy The working fluid in a machine is the pressurized gas or liquid which actuates the machine It uses the principle of proportional control. A proportional control system is a type of linear Feedback Control system.

It is most obviously seen on steam engines where it regulates the admission of steam into the cylinder(s). A steam engine is a Heat engine that performs Mechanical work using Steam as its Working fluid. A cylinder is the central working part of a Reciprocating engine, the space in which a Piston travels It is also found on internal combustion engines and variously fueled turbines, and in some modern striking clocks. The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a A turbine is a rotary Engine that extracts Energy from a Fluid flow

Operation

Drawing of a centrifugal "flyball" governor

The device shown is from a steam engine. It is connected to a throttle valve that regulates the flow of working fluid (steam) supplying the prime mover (prime mover not shown). A throttle is the mechanism by which the flow of a fluid is managed by constriction or obstruction The working fluid in a machine is the pressurized gas or liquid which actuates the machine In Locomotives, a prime mover is the primary source of power to run the locomotive As the speed of the prime mover increases, the central spindle of the governor rotates at a faster rate and the kinetic energy of the balls increases. This allows the two masses on lever arms to move outwards and upwards against gravity. Mass is a fundamental concept in Physics, roughly corresponding to the Intuitive idea of how much Matter there is in an object If the motion goes far enough, this motion causes the lever arms to pull down on a thrust bearing, which moves a beam linkage, which reduces the aperture of a throttle valve. A thrust bearing is a particular type of rotary bearing. Like other rotary bearings they permit rotation between parts but they are designed to support a high Axial The rate of working-fluid entering the cylinder is thus reduced and the speed of the prime mover is controlled, preventing over-speeding.

Mechanical stops may be used to limit the range of throttle motion, as seen near the masses in the image at right.

The direction of the lever arm holding the mass will be along the vector sum of the reactive centrifugal force vector and the gravitational force. A reactive centrifugal force is the reaction Force to a Centripetal force.

History

James Watt designed his first governor in 1788 following a suggestion from his business partner Matthew Boulton. James Watt ( 19 January 1736 &ndash 25 August 1819 Boulton proved to be an excellent businessman and both men eventually made fortunes Year 1788 ( MDCCLXXXVIII) was a Leap year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a Leap Matthew Boulton ( September 3, 1728 &ndash 18 August 1809) was an English Manufacturer and Engineer. It was a conical pendulum governor and one of the final series of innovations Watt had employed for steam engines. A cone is a three-dimensional Geometric shape that tapers smoothly from a flat round base to a point called the apex or vertex James Watt never claimed the centrifugal governor to be an invention of his own. Centrifugal governors were used to regulate the distance and pressure between millstones in windmills since the 17th century. Millstones or mill stones are used in Windmills and Watermills including Tide mills for grinding Wheat or other grains A windmill is a machine that is powered by the energy of the wind It is therefore a misunderstanding that James Watt is the inventor of this device.

A giant statue of Watt's governor stands at Smethwick in the English West Midlands. A statue is a Sculpture in the round representing a person or persons an animal or an event normally full-length as opposed to a bust, and at least close to life-size Smethwick (pronounced 'Smethick' is a town in the Metropolitan Borough of Sandwell, in the West Midlands of England. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland The West Midlands is a Metropolitan county in western central England with a population of 2591300 It is known as the flyball governor.

Another kind of centrifugal governor consists of a pair of masses on a spindle inside a cylinder, the masses or the cylinder being coated with pads. This is used in a spring-loaded record player and a spring-loaded telephone dial to limit the speed. The phonograph, or gramophone, was the most common device for playing recorded Sound from the 1870s through the 1980s Basic principle A traditional landline telephone system also known as "plain old telephone service" (POTS, commonly handles both signaling and audio information

Dynamic systems

The centrifugal governor is often used in the cognitive sciences as an example of a dynamic system, in which the representation of information cannot be clearly separated from the operations being applied to the representation. Tim van Gelder is an Australian cognitive scientist. He is Principal Fellow in the Philosophy Department at the University of Melbourne, and And because the governor is a servomechanism, its analysis in a dynamic system is far from trivial. A servomechanism, or servo is an automatic device which uses error-sensing Feedback to correct the performance of a mechanism James Clerk Maxwell wrote a famous paper "On governors"^[1], which is quite frequently considered a classical paper in feedback control theory, in 1868. James Clerk Maxwell (13 June 1831 &ndash 5 November 1879 was a Scottish mathematician and theoretical physicist. Control theory is an interdisciplinary branch of Engineering and Mathematics, that deals with the behavior of Dynamical systems The desired output Maxwell distinguishes moderators (a centrifugal brake) and governors which control motive power input. A brake is a device for slowing or stopping the motion of a Machine or Vehicle, or alternatively a device to restrain it from starting to move again In Thermodynamics, motive power is an agency as Water or Steam, used to impart motion. Input is the term denoting either an entrance or changes which are inserted into a System and which activate/modify a Process. He considers devices by Watt, Professor James Thomson, Mr. James Watt ( 19 January 1736 &ndash 25 August 1819 Boulton proved to be an excellent businessman and both men eventually made fortunes James Thomson ( February 16, 1822 - May 8, 1892) was an Irish Engineer and Physicist whose reputation would have Fleeming Jenkin, Sir William Thomson, M. Henry Charles Fleeming Jenkin ( 25 March 1833 &ndash 12 June 1885) was Professor of Engineering at the University William Thomson 1st Baron Kelvin (or Lord Kelvin) OM, GCVO, PC, PRS, FRSE, (26 June 1824 &ndash 17 December 1907 Leon Foucault and Mr Carl Wilhelm Siemens (a liquid governor). Jean Bernard Léon Foucault (ʒɑ̃ bɛʁnaʁ leɔ̃ fu'ko ( 18 September 1819 &ndash 11 February 1868) was a French physicist Carl Wilhelm Siemens (en Charles William Siemens, known as Sir William Siemens) ( 4 April, 1823 &ndash 19 November, 1883

In a largely overlooked passage of his famous 1858 paper to the Linnean Society (which led Darwin to publish his monumental On the Origin of Species) Wallace says of the evolutionary principle:

The action of this principle is exactly like that of the centrifugal governor of the steam engine, which checks and corrects any irregularities almost before they become evident; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any conspicuous magnitude, because it would make itself felt at the very first step, by rendering existence difficult and extinction almost sure soon to follow. The Linnean Society of London is the World 's premier society for the study and dissemination of Taxonomy and natural history Charles Robert Darwin (February 12 1809 &ndash April 19 1882 was an English naturalist, who realised and demonstrated that all Species of life Charles Darwin 's On the Origin of Species (published 24 November 1859) is a seminal work in Scientific literature and arguably the Alfred Russel Wallace OM, FRS (8 January 1823 &ndash 7 November 1913 was an British naturalist, Explorer, Geographer eVolution is the third Album by eLDee, it was due to be released in 2008 ^[2].

The cybernetician and anthropologist Gregory Bateson would observe in the 1970s that though seeing it only as an illustration, Wallace had "probably said the most powerful thing that’d been said in the 19^th Century". Cybernetics is the interdisciplinary study of the Structure of Complex systems especially Communication processes control mechanisms and Feedback Gregory Bateson ( 9 May 1904 – 4 July 1980) was a British anthropologist, social scientist, linguist ^[3] Bateson revisited the topic in his 1979 book Mind and Nature: A Necessary Unity, and other scholars have continued to explore the connection between natural selection and systems theory. Systems theory is an Interdisciplinary field of Science and the study of the nature of Complex systems in Nature, Society, and ^[4]

References

1. ^ J. C. Maxwell "On Governors" Proceedings of the Royal Society of London, Vol. 16, 1868, pp. 270-283
2. ^ Wallace, Alfred. the Tendency of Varieties to Depart Indefinitely From the Original Type
3. ^ Brand, Stewart. For God’s Sake, Margaret. CoEvolutionary Quarterly, June 1976. Retrieved on 2007-04-04. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1581 - Francis Drake completes a circumnavigation of the world and is knighted by Elizabeth I.
4. ^ Smith, Charles H. . Wallace's Unfinished Business. Complexity (publisher Wiley Periodicals, Inc. ) Volume 10, No 2, 2004. Retrieved on 2007-05-11. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 330 - Byzantium is renamed ''Nova Roma'' during a dedication ceremony but is more popularly referred to as Constantinople

See also

• Hit and miss engine