{"id":88,"date":"2020-04-13T17:22:21","date_gmt":"2020-04-13T17:22:21","guid":{"rendered":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/?page_id=88"},"modified":"2026-05-13T06:13:58","modified_gmt":"2026-05-13T06:13:58","slug":"centrifugalgovernor","status":"publish","type":"page","link":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/exhibits\/mechanics\/centrifugalgovernor\/","title":{"rendered":"Centrifugal Governor"},"content":{"rendered":"<h1 style=\"margin-top:var(--wp--preset--spacing--50);margin-bottom:var(--wp--preset--spacing--20)\" class=\"is-style-mini-bar wp-block-post-title\">Centrifugal Governor<\/h1>\n\n\n<div class=\"wp-block-group alignfull has-base-background-color has-background has-global-padding is-layout-constrained wp-block-group-is-layout-constrained\" style=\"margin-top:0;margin-bottom:0;padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--60)\">\n<div class=\"wp-block-columns alignnone is-layout-flex wp-container-core-columns-is-layout-b4b75a54 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-group is-layout-constrained has-global-padding wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading\">WHAT TO DO<\/h2>\n\n\n\n<ul class=\"wp-block-list is-style-more-space\">\n<li>Turn the handle at a <strong>constant<\/strong> speed. You are acting as an engine!<\/li>\n\n\n\n<li>Then, increase the speed suddenly.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><u>What changes do you see when you increase the speed suddenly?<\/u><\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-b4b75a54 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image alignright size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"161\" height=\"121\" src=\"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/Governor-001.jpg\" alt=\"\" class=\"wp-image-89\"\/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<p class=\"has-text-align-center wp-block-paragraph\"><figure><img loading=\"lazy\" decoding=\"async\" width=\"60\" height=\"23\" class=\"alignnone size-full wp-image-90\" src=\"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/LeftArrow.gif\" alt=\"\"><\/figure><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<p class=\"has-text-align-left wp-block-paragraph\">Pay attention to the throttle valve<\/p>\n<\/div>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Answer<\/strong>: The rotating masses move to a larger radius, and the throttle valve&nbsp;closes partially.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>WHY: <\/strong>The centrifugal governor is an application of Newton\u2019s 3<sup>rd<\/sup> law.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><u>Newton<\/u><\/strong><strong><u>\u2019s 3<sup>rd<\/sup> law<\/u><\/strong><strong>: For every action there is an equal and opposite reaction.<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image alignright\"><img loading=\"lazy\" decoding=\"async\" width=\"381\" height=\"112\" src=\"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/CirMotion.jpg\" alt=\"\" class=\"wp-image-91\" srcset=\"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/CirMotion.jpg 381w, https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/CirMotion-300x88.jpg 300w\" sizes=\"auto, (max-width: 381px) 100vw, 381px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><br>Think&nbsp;of swirling a stone at the end of a string. The string exerts the centripetal force, keeping the stone in its circular motion. This is the <u>action<\/u>. The equal and opposite <u>reaction<\/u> to that is reactive centrifugal force of the string on your hand.<\/p>\n\n\n\n<figure class=\"wp-block-image alignleft\"><img loading=\"lazy\" decoding=\"async\" width=\"145\" height=\"120\" src=\"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/Ball-forces.png\" alt=\"\" class=\"wp-image-92\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><br>In the <strong><u>centrifugal governor<\/u><\/strong>, the horizontal centripetal force on each spinning ball is the&nbsp;sum of the downward force of gravity and the tension from the rod supporting the ball. This centripetal force keeps the balls in motion around the center post.<\/p>\n\n\n\n<figure class=\"wp-block-image alignleft\"><img loading=\"lazy\" decoding=\"async\" width=\"159\" height=\"121\" src=\"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/Forces.jpg\" alt=\"\" class=\"wp-image-93\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><br>From Newton\u2019s 3<sup>rd<\/sup> law, we know that there is a reaction force for each of these forces, with equal size but pushing in the opposite direction. Since the rods are not fixed at one angle, the reactive centrifugal force pulls the balls outward from the center post with a higher rotational velocity. This also changes the positions of the rods, which are connected to a lever controlling the throttle valve.<\/p>\n\n\n\n<figure class=\"wp-block-image alignright\"><img loading=\"lazy\" decoding=\"async\" width=\"220\" height=\"293\" src=\"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-content\/uploads\/sites\/10\/2020\/04\/centrif-1.jpg\" alt=\"\" class=\"wp-image-95\"\/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><br><strong><u>Centrifugal governors<\/u><\/strong> have been used since the 17<sup>th <\/sup>century, when they were used to&nbsp;regulate the distance and pressure between <strong>millstones in windmills<\/strong>. In a <strong>steam engine<\/strong>, it regulates the speed of the&nbsp;engine by controlling the flow of steam to it. If the speed of the engine increases, the rotating masses will swing out to a larger radius and trigger a cut in the&nbsp;<u>throttle<\/u>&nbsp;thus decreasing the flow of steam to the engine and keeping the speed of the engine constant. In <strong>snowmobiles and ATVs<\/strong>, it can vary the transmission&#8217;s pulley diameter ratio in relation to the engine rotations per minute.<\/p>\n\n\n<div style=\"font-size: 1.125rem\" class=\"is-style-blockquote wp-block-uw-blocks-uw-quote\">\n\t<blockquote>Original 1918 Museum Exhibit, Updated<\/blockquote>\n\t<div class=\"uw-quote-bottom-container\">\n\t\t\t<\/div>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"Gaussian_Probability_Board.2C_1A20.10\"><i><b><a href=\"https:\/\/wiki.physics.wisc.edu\/facultywiki\/Demonstrations\">Physics Lecture Demonstration Database<\/a> <\/b><\/i><\/p>\n\n\n\n<ul class=\"wp-block-list is-style-more-space\">\n<li><p id=\"Centrifugal_Governor.2C\"><a href=\"https:\/\/wiki.physics.wisc.edu\/facultywiki\/Centri_Governor\">Centrifugal Governor<\/a><\/p><br><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>WHAT TO DO What changes do you see when you increase the speed suddenly? Pay attention to the throttle valve Answer: The rotating masses move to a larger radius, and the throttle valve&nbsp;closes partially. WHY: The centrifugal governor is an application of Newton\u2019s 3rd law. Newton\u2019s 3rd law: For every action there is an equal &hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":50,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uw_migration_status":"complete","_uw_gutenberg_post_content_before_migration":"","_uw_seo_meta_title":"","_uw_seo_meta_description":"","_uw_seo_twitter_card_type":"","_uw_seo_meta_image":"","_uw_seo_meta_image_url":"","_uw_seo_meta_image_sizes":[],"_uw_seo_custom_meta_tags":[],"footnotes":""},"class_list":["post-88","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/88","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/comments?post=88"}],"version-history":[{"count":9,"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/88\/revisions"}],"predecessor-version":[{"id":975,"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/88\/revisions\/975"}],"up":[{"embeddable":true,"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/pages\/50"}],"wp:attachment":[{"href":"https:\/\/www.physics.wisc.edu\/ingersollmuseum\/wp-json\/wp\/v2\/media?parent=88"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}