{"id":1896,"date":"2016-12-13T11:00:03","date_gmt":"2016-12-13T17:00:03","guid":{"rendered":"http:\/\/blog.misumiusa.com\/?p=1896"},"modified":"2021-11-02T16:58:38","modified_gmt":"2021-11-02T21:58:38","slug":"sliding-guides-pt-2-friction-wear","status":"publish","type":"post","link":"https:\/\/blog.misumiusa.com\/sliding-guides-pt-2-friction-wear\/","title":{"rendered":"Sliding Guides Pt 2: Friction & Wear"},"content":{"rendered":"

Linear motion components<\/a>, linear shafts<\/a> and linear bushings<\/a> have different features available to avoid friction.\u00a0 Friction forces are generated when solid objects in contact make relative motion. It is one force linear motion must overcome for smooth movement in accurate applications.\u00a0 Friction coefficient is the unit of measure for friction force.\u00a0 This is what increases the amount of force required to move an object.\u00a0 These friction forces must be managed properly with lubrication and etc, or may result in troubles shown below.<\/p>\n

    \n
  1. Friction of solid objects resulting in seizures.<\/li>\n
  2. Wear occurs and at an accelerated rate.<\/li>\n
  3. Increased power loss.<\/li>\n<\/ol>\n

    About Friction<\/strong><\/p>\n

    There are two types of friction.
    \nA) Sliding Friction
    \nB) Rolling Friction<\/p>\n

    The sliding friction is the type seen with\u00a0Gib Slides, skies and sleds. The [Fig.] shown below is an ancient Egyptian mural. It depicts a scene of transporting a large stone statue. A man can be seen at the center pouring friction reducing lubrication.<\/p>\n

    \"egypt\"<\/p>\n

    Shown below are friction coefficients of various material combinations. In Figure 1 there is a free body diagram of an object being dragged.<\/p>\n

    \"friction\"<\/p>\n

    Figure 1<\/p>\n

     <\/p>\n

    -Frictional force can be expressed as Ff<\/sub> = \u00b5N<\/p>\n

    -\u03bc = static (\u03bcs<\/sub>) or kinetic (\u03bck<\/sub>) frictional coefficient<\/p>\n

    -N = normal force (N, lb) = mg (mass, gravity)<\/p>\n\n\n\n\n\n\n
    Material Combinations<\/strong><\/td>\nFriction Coefficient \u03bc<\/strong><\/td>\n<\/tr>\n
    Mild Steel vs. Mild Steel<\/td>\n0.4<\/td>\n<\/tr>\n
    Hard Steel vs. molybdenum disulfide<\/td>\n0.15<\/td>\n<\/tr>\n
    Skies vs. Snow<\/td>\n0.05<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    The rolling friction can be represented by linear motion guides,\u00a0miniature ball guides, and etc. where friction occurs with balls and\u00a0rollers. If the sliding friction is to be defied as the “Sled Era”, the rolling friction can be dabbed as the “Rolling Cart Era”.<\/p>\n

    \"linear<\/p>\n

    Figure 2 Linear Motion Guides<\/p>\n

    Rolling friction coefficient examples are shown below. (Sliding friction coefficient and rolling friction coefficient cannot be compared equally.)<\/p>\n\n\n\n\n\n\n
    Material Combinations<\/strong><\/td>\nRolling Friction Coefficient f(cm)<\/strong><\/td>\n<\/tr>\n
    Hardened Steel vs. Roller\/Balls<\/td>\n0.0005\u301c0.001<\/td>\n<\/tr>\n
    Mild Steel vs. Mild Steel<\/td>\n0.02\u301c0.05<\/td>\n<\/tr>\n
    Pneumatic Tire vs. Road<\/td>\n0.05\u301c0.15<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    About Wear<\/strong><\/p>\n

    When solid objects are in contact without any lubrication between them, minute surface features are in directly coupled states. Friction occurs when these coupled features are decoupled by sliding motion, and this is the friction resistance (force). When the decoupling occurs, minuscule sections of material are ripped away where they contact. This is the wear. When the friction increases, the wear simply increases also. Proper lubrication is needed to prevent this wearing. Selecting appropriate lubrication is important, especially for mechanisms with high motion speeds and clean room applications.\u00a0 If adding lubrication is not possible, there are self-lubricating linear bushings available.<\/p>\n

    The possibilities are endless! Choosing the correct style of linear motion components for your application is crucial for friction and wear prevention.\u00a0 Considering these factors will bring you longer life to your design.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Linear motion components, linear shafts and linear bushings have different features available to avoid friction.\u00a0 Friction forces are generated when solid objects in contact make relative motion. It is one force linear motion must overcome for smooth movement in accurate applications.\u00a0 Friction coefficient is the unit of measure for friction force.\u00a0 This is what increases the amount of force required […]<\/p>\n","protected":false},"author":46,"featured_media":1904,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false},"categories":[1136],"tags":[324,337,89,338],"aioseo_notices":[],"gutentor_comment":1,"_links":{"self":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts\/1896"}],"collection":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/users\/46"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/comments?post=1896"}],"version-history":[{"count":8,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts\/1896\/revisions"}],"predecessor-version":[{"id":1906,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/posts\/1896\/revisions\/1906"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/media\/1904"}],"wp:attachment":[{"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/media?parent=1896"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/categories?post=1896"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.misumiusa.com\/wp-json\/wp\/v2\/tags?post=1896"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}