Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Governor (device)
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
== History == {{See also|Control theory}} [[File:Centrifugal governor and balanced steam valve (New Catechism of the Steam Engine, 1904).jpg|thumb|Cut-away drawing of steam engine speed governor. The valve starts fully open at zero speed, and is closed as the balls rotate and rise. The speed sensing drive shaft is top right]] [[File:Ashton Frost engine governor.jpg|thumb|Porter governor on a Corliss steam engine]][[Centrifugal governor]]s were used to regulate the distance and pressure between [[millstone]]s in [[windmill]]s since the 17th century. Early [[steam engine]]s employed a purely reciprocating motion, and were used for pumping water β an application that could tolerate variations in the working speed. It was not until the Scottish engineer [[James Watt]] introduced the ''rotative'' steam engine, for driving factory machinery, that a constant operating speed became necessary. Between the years 1775 and 1800, Watt, in partnership with industrialist [[Matthew Boulton]], produced some 500 rotative [[beam engine]]s. At the heart of these engines was Watt's self-designed "conical pendulum" governor: a set of revolving steel balls attached to a vertical spindle by link arms, where the controlling force consists of the weight of the balls. The theoretical basis for the operation of governors was described by [[James Clerk Maxwell]] in 1868 in his seminal paper 'On Governors'.<ref name="ben93p48">{{Cite book| publisher = IET | isbn = 978-0-86341-299-8 | last = Bennett | first = Stuart | title = A history of control engineering, 1930-1955 | year = 1992 | page = [https://books.google.com/books?id=VD_b81J3yFoC&pg=PA48 p. 48] }}</ref> Building on Watt's design was American engineer [[Willard Gibbs]] who in 1872 theoretically analyzed Watt's conical pendulum governor from a mathematical energy balance perspective. During his Graduate school years at [[Yale University]], Gibbs observed that the operation of the device in practice was beset with the disadvantages of sluggishness and a tendency to over-correct for the changes in speed it was supposed to control.<ref>{{Citation | last = Wheeler | first = Lynder Phelps | contribution = The Gibbs Governor for Steam Engines | year = 1947 | title = The Early Work of Willard Gibbs in Applied Mechanics | editor-last = Wheeler | editor-first = Lynder Phelps | editor2-last = Waters | editor2-first = Everett Oyler | editor3-last = Dudley | editor3-first = Samuel William | pages = 63β78 | place = New York | publisher = Henry Schuman }}</ref> Gibbs theorized that, analogous to the equilibrium of the simple Watt governor (which depends on the balancing of two torques: one due to the weight of the "balls" and the other due to their rotation), [[thermodynamic equilibrium]] for any work producing [[thermodynamic system]] depends on the balance of two entities. The first is the [[heat]] energy supplied to the intermediate substance, and the second is the [[Work (thermodynamics)|work]] energy performed by the intermediate substance. In this case, the intermediate substance is steam. These sorts of theoretical investigations culminated in the 1876 publication of Gibbs' famous work ''On the Equilibrium of Heterogeneous Substances'' and in the construction of the Gibbsβ governor. These formulations are ubiquitous today in the natural sciences in the form of the Gibbs' [[Gibbs free energy|free energy]] equation, which is used to determine the equilibrium of chemical reactions; also known as ''Gibbs equilibrium''.<ref>Wheeler, L. (1951). ''Josiah Willard Gibbs - the History of a Great Mind.'' Woodbridge, CT: Ox Bow Press.</ref> Governors were also to be found on early motor vehicles (such as the 1900 [[Wilson-Pilcher]]), where they were an alternative to a hand throttle. They were used to set the required engine speed, and the vehicle's throttle and timing were adjusted by the governor to hold the speed constant, similar to a modern [[cruise control]]. Governors were also optional on utility vehicles with engine-driven accessories such as winches or hydraulic pumps (such as [[Land Rover]]s), again to keep the engine at the required speed regardless of variations of the load being driven.
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)