{"id":230,"date":"2025-10-31T00:25:51","date_gmt":"2025-10-31T00:25:51","guid":{"rendered":"https:\/\/vibromera.eu\/glossary\/self-excited-vibration\/"},"modified":"2026-05-23T22:39:08","modified_gmt":"2026-05-23T22:39:08","slug":"self-excited-vibration","status":"publish","type":"glossary","link":"https:\/\/vibromera.eu\/da\/glossary\/self-excited-vibration\/","title":{"rendered":"Hvad er selvophidsede vibrationer? \u2013 Ustabile systemresponser"},"content":{"rendered":"<h1>Forst\u00e5else af selvexciterede vibrationer<\/h1>\n\t\t<section class=\"woocommerce hestia-shop products is-shortcode\" id=\"products\" data-sorder=\"hestia_shop\" >\n\t\t\t\t\t\t<div class=\"\">\n\t\t\t\t\t\t<div class=\"hestia-shop-content\">\n\t\t\t<div class=\"row\" data-aos=\"fade-up\" >\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/balanset-1\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/balanset-1\/\" title=\"B\u00e6rbart afbalanceringsapparat og vibrationsanalysator Balanset-1A\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Balanset-1A komplet s\u00e6t med b\u00e6rbar afbalanceringsenhed og vibrationsanalysator\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-18x12.webp 18w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/09\/77-e1693745667801-272x182.webp 272w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/da\/product-category\/devices\/\" rel=\"tag\">Enheder<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/da\/product\/balanset-1\/\" title=\"B\u00e6rbart afbalanceringsapparat og vibrationsanalysator Balanset-1A\">B\u00e6rbart afbalanceringsapparat og vibrationsanalysator Balanset-1A<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">\u20ac<\/span>1,975.00<\/span> + moms (hvis relevant)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=986\" data-quantity=\"1\" data-product_id=\"986\" data-product_sku=\"BS-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Tilf\u00f8j til kurv\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Tilf\u00f8j til kurv\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=986\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_986\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"986\" data-product_sku=\"BS-1\" aria-label=\"L\u00e6g i kurv: \u201cPortable balancer &amp; Vibration analyzer Balanset-1A\u201d\" rel=\"nofollow\" data-success_message=\"\u201cPortable balancer &amp; Vibration analyzer Balanset-1A\u201d er blevet tilf\u00f8jet til din kurv\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Tilf\u00f8j til kurv<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_986\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/vibration-sensor\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/vibration-sensor\/\" title=\"Vibrationssensor\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Balanset-1A vibrationssensor i n\u00e6rbillede\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-1024x682.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-3.webp 1280w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/da\/product-category\/parts\/\" rel=\"tag\">Dele<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/da\/product\/vibration-sensor\/\" title=\"Vibrationssensor\">Vibrationssensor<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">\u20ac<\/span>90.00<\/span> + moms (hvis relevant)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1820\" data-quantity=\"1\" data-product_id=\"1820\" data-product_sku=\"VS-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Tilf\u00f8j til kurv\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Tilf\u00f8j til kurv\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1820\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1820\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1820\" data-product_sku=\"VS-1\" aria-label=\"L\u00e6g i kurv: \u201cVibration sensor\u201d\" rel=\"nofollow\" data-success_message=\"\u201cVibration sensor\u201d er blevet tilf\u00f8jet til din kurv\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Tilf\u00f8j til kurv<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1820\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/optical-sensor-for-balanset-and-arbalance\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/optical-sensor-for-balanset-and-arbalance\/\" title=\"Optisk sensor (laser-tachometer)\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Optisk sensor (laser-tachometer)\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-1024x682.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-1536x1023.webp 1536w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-18x12.webp 18w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-460x306.webp 460w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/ZKqzGXSCCBU.webp 1600w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/da\/product-category\/parts\/\" rel=\"tag\">Dele<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/da\/product\/optical-sensor-for-balanset-and-arbalance\/\" title=\"Optisk sensor (laser-tachometer)\">Optisk sensor (laser-tachometer)<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">\u20ac<\/span>124.00<\/span> + moms (hvis relevant)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1832\" data-quantity=\"1\" data-product_id=\"1832\" data-product_sku=\"Tach-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Tilf\u00f8j til kurv\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Tilf\u00f8j til kurv\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1832\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1832\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1832\" data-product_sku=\"Tach-1\" aria-label=\"L\u00e6g i kurv: \u201cOptical Sensor (Laser Tachometer)\u201d\" rel=\"nofollow\" data-success_message=\"\u201cOptical Sensor (Laser Tachometer)\u201d er blevet tilf\u00f8jet til din kurv\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Tilf\u00f8j til kurv<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1832\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/balanset-4\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/balanset-4\/\" title=\"Balanset-4\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Vibromera rotorbalanceringss\u00e6t: b\u00e6retaske, flerkanals signalbehandler, h\u00e5ndholdt analysator, magnetisk base, vibrationssensorer og spiralkabler.\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-18x12.webp 18w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-460x306.webp 460w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2022\/12\/balkom4.webp 640w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/da\/product-category\/devices\/\" rel=\"tag\">Enheder<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/da\/product\/balanset-4\/\" title=\"Balanset-4\">Balanset-4<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">\u20ac<\/span>6,803.00<\/span> + moms (hvis relevant)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1833\" data-quantity=\"1\" data-product_id=\"1833\" data-product_sku=\"BS-4\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Tilf\u00f8j til kurv\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Tilf\u00f8j til kurv\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1833\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1833\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1833\" data-product_sku=\"BS-4\" aria-label=\"L\u00e6g i kurv: \u201cBalanset-4\u201d\" rel=\"nofollow\" data-success_message=\"\u201cBalanset-4\u201d er blevet tilf\u00f8jet til din kurv\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Tilf\u00f8j til kurv<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1833\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div><!-- \/.row --><div class=\"row\">\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/magnet-stand\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/magnet-stand\/\" title=\"Magnetisk stativ Insize-60-kgf\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Magnetbase.\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-1024x682.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2018\/05\/IMG-36.webp 1280w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/da\/product-category\/parts\/\" rel=\"tag\">Dele<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/da\/product\/magnet-stand\/\" title=\"Magnetisk stativ Insize-60-kgf\">Magnetisk stativ Insize-60-kgf<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">\u20ac<\/span>46.00<\/span> + moms (hvis relevant)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1852\" data-quantity=\"1\" data-product_id=\"1852\" data-product_sku=\"MS-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Tilf\u00f8j til kurv\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Tilf\u00f8j til kurv\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=1852\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_1852\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"1852\" data-product_sku=\"MS-1\" aria-label=\"L\u00e6g i kurv: \u201cMagnetic Stand Insize-60-kgf\u201d\" rel=\"nofollow\" data-success_message=\"\u201cMagnetic Stand Insize-60-kgf\u201d er blevet tilf\u00f8jet til din kurv\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Tilf\u00f8j til kurv<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_1852\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/reflective-tape\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/reflective-tape\/\" title=\"Reflekterende tape\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Reflekterende tape\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-16x12.webp 16w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-460x306.webp 460w, https:\/\/vibromera.eu\/wp-content\/uploads\/2023\/05\/s-l1600-272x182.webp 272w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/da\/product-category\/parts\/\" rel=\"tag\">Dele<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/da\/product\/reflective-tape\/\" title=\"Reflekterende tape\">Reflekterende tape<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">\u20ac<\/span>10.00<\/span> + moms (hvis relevant)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=2329\" data-quantity=\"1\" data-product_id=\"2329\" data-product_sku=\"rt-1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Tilf\u00f8j til kurv\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Tilf\u00f8j til kurv\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=2329\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_2329\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"2329\" data-product_sku=\"rt-1\" aria-label=\"L\u00e6g i kurv: \u201cReflective tape\u201d\" rel=\"nofollow\" data-success_message=\"\u201cReflective tape\u201d er blevet tilf\u00f8jet til din kurv\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Tilf\u00f8j til kurv<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_2329\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t<div class=\"col-ms-6 col-sm-6 col-md-3 shop-item\">\n\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/dynamic-balancer-balanset-1a\/\" class=\"woocommerce-LoopProduct-link woocommerce-loop-product__link\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"card-image\">\n\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/vibromera.eu\/da\/product\/dynamic-balancer-balanset-1a\/\" title=\"Dynamisk balancer &quot;Balanset-1A&quot; OEM\">\n\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"230\" height=\"153\" src=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-230x153.webp\" class=\"attachment-woocommerce_thumbnail size-woocommerce_thumbnail\" alt=\"Balanset-1A-s\u00e6t med interface-enhed, sensorer, omdrejningst\u00e6ller og tilbeh\u00f8r\" srcset=\"https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-230x153.webp 230w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-600x400.webp 600w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-300x200.webp 300w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-1024x683.webp 1024w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-768x512.webp 768w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-1536x1024.webp 1536w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-2048x1366.webp 2048w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-360x240.webp 360w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-272x182.webp 272w, https:\/\/vibromera.eu\/wp-content\/uploads\/2021\/11\/\u0411\u0430\u043b\u043a\u043e\u043c\u041a\u0438\u0442-scaled-e1732998877834.webp 708w\" sizes=\"auto, (max-width: 230px) 100vw, 230px\" \/>\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t<div class=\"ripple-container\"><\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<div class=\"content\">\n\t\t\t\t\t\t\t\t<span class=\"category\"><a href=\"https:\/\/vibromera.eu\/da\/product-category\/devices\/\" rel=\"tag\">Enheder<\/a><\/span>\n\t\t\t\t\t\t\t\t<h4 class=\"card-title\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"shop-item-title-link\" href=\"https:\/\/vibromera.eu\/da\/product\/dynamic-balancer-balanset-1a\/\" title=\"Dynamisk balancer &quot;Balanset-1A&quot; OEM\">Dynamisk balancer \"Balanset-1A\" OEM<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t<div class=\"footer\">\n\n\t\t\t\t\t\t\t\t\t<div class=\"price\"><h4><span class=\"woocommerce-Price-amount amount\"><span class=\"woocommerce-Price-currencySymbol\">\u20ac<\/span>1,735.00<\/span> + moms (hvis relevant)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t<div class=\"stats\">\n\t\t\t\t\t\t\t\t\t\t<a rel=\"nofollow\" href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=4193\" data-quantity=\"1\" data-product_id=\"4193\" data-product_sku=\"BS-1OEM\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart btn btn-just-icon btn-simple btn-default\" title=\"Tilf\u00f8j til kurv\" data-no-translation-title=\"\"><i rel=\"tooltip\" data-original-title=\"Tilf\u00f8j til kurv\" class=\"fas fa-cart-plus\" data-no-translation-data-original-title=\"\"><\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a><a href=\"\/da\/wp-json\/wp\/v2\/glossary\/230?add-to-cart=4193\" aria-describedby=\"woocommerce_loop_add_to_cart_link_describedby_4193\" data-quantity=\"1\" class=\"button product_type_simple add_to_cart_button ajax_add_to_cart\" data-product_id=\"4193\" data-product_sku=\"BS-1OEM\" aria-label=\"L\u00e6g i kurv: \u201cDynamic balancer \u201cBalanset-1A\u201d OEM\u201d\" rel=\"nofollow\" data-success_message=\"\u201cDynamic balancer \u201cBalanset-1A\u201d OEM\u201d er blevet tilf\u00f8jet til din kurv\" data-no-translation=\"\" data-trp-gettext=\"\" data-no-translation-aria-label=\"\" data-no-translation-data-success_message=\"\">Tilf\u00f8j til kurv<\/a>\t<span id=\"woocommerce_loop_add_to_cart_link_describedby_4193\" class=\"screen-reader-text\">\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/section>\n\t\t\n<p><strong>Selvophidsede vibrationer<\/strong> \u2014 ogs\u00e5 kaldet selvinduceret eller ustabil vibration \u2014 er en s\u00e6rlig farlig form for bev\u00e6gelse, hvor et systems bev\u00e6gelse selv skaber de kr\u00e6fter, der opretholder eller forst\u00e6rker denne bev\u00e6gelse. Resultatet er en lukket tilbagekoblingskreds: Vibrationen skaber sin egen drivkraft, s\u00e5 amplituden kan vokse, undertiden til et katastrofalt niveau, uden at den eksterne p\u00e5virkning overhovedet \u00f8ges. Det er mekanismen bag flere af de mest frygtede ustabiliteter i <a href=\"https:\/\/vibromera.eu\/da\/glossary\/rotor-dynamics\/\">rotordynamik<\/a>, og at kunne genkende det hurtigt er en central diagnostisk f\u00e6rdighed.<\/p>\n<p>Dette adskiller sig fundamentalt fra en <a href=\"https:\/\/vibromera.eu\/da\/glossary\/forced-vibration\/\">tvungen vibration<\/a> such as <a href=\"https:\/\/vibromera.eu\/da\/glossary\/unbalance\/\">ubalance<\/a> eller <a href=\"https:\/\/vibromera.eu\/da\/glossary\/misalignment\/\">fejljustering<\/a>, hvor vibrationen er en direkte, proportional reaktion p\u00e5 en bestemt periodisk excitation ved en kendt drivfrekvens. Fordobler man ubalancen, fordobles reaktionen; fjerner man excitationen, oph\u00f8rer vibrationen. I et selvexciteret system findes der ikke et s\u00e5dant eksternt ur \u2014 bev\u00e6gelsen driver sig selv, og den energi, der driver den, hentes fra en konstant kilde, s\u00e5som rotation, v\u00e6skestr\u00f8mning eller en sk\u00e6reproces.<\/p>\n<h2>1. Feedbackmekanismen<\/h2>\n<p>Mekanismen bag en selvophidset svingning kan beskrives som en r\u00e6kke trin:<\/p>\n<ol>\n<li>Et system \u2013 for eksempel en rotor, der drejer i sit leje \u2013 er i j\u00e6vn bev\u00e6gelse.<\/li>\n<li>En lille, tilf\u00e6ldig forstyrrelse medf\u00f8rer en svag forskydning eller \u00e6ndring i hastigheden.<\/li>\n<li>Denne \u00e6ndring i bev\u00e6gelsen \u00e6ndrer de kr\u00e6fter, der virker p\u00e5 systemet \u2014 for eksempel v\u00e6sketrykket i en <a href=\"https:\/\/vibromera.eu\/da\/glossary\/journal-bearing\/\">journalleje<\/a> eller sk\u00e6rekraften p\u00e5 et v\u00e6rkt\u00f8j.<\/li>\n<li>Det afg\u00f8rende er, at den \u00e6ndrede kraft virker p\u00e5 en s\u00e5dan m\u00e5de, at <em>add energy<\/em> til systemet, hvilket skubber komponenten yderligere i den retning, den allerede bev\u00e6gede sig i.<\/li>\n<li>Den \u00f8gede bev\u00e6gelse skaber en endnu st\u00f8rre kraft, som tilf\u00f8rer endnu mere energi \u2014 og s\u00e5dan forts\u00e6tter det.<\/li>\n<\/ol>\n<p>Reguleringskredsl\u00f8bet \u00f8ger amplituden, indtil den bremses af ikke-lineariteter i systemet (rotoren rammer et h\u00e5rdt anslag, en t\u00e6tning lukker et spillerum) eller indtil noget g\u00e5r i stykker. Den centrale fysiske indsigt handler om energibalancen: der opst\u00e5r en ustabilitet, n\u00e5r den bev\u00e6gelsesafh\u00e6ngige kraft tilf\u00f8rer energi hurtigere end systemets <a href=\"https:\/\/vibromera.eu\/da\/glossary\/damping\/\">d\u00e6mpning<\/a> kan aflede den. Tilstr\u00e6kkelig d\u00e6mpning er derfor det f\u00f8rste forsvar mod selvophidselse.<\/p>\n<h2>2. Typiske eksempler p\u00e5 selvinduceret svingning<\/h2>\n<p>Flere velkendte f\u00e6nomener inden for maskindiagnostik er klassiske eksempler p\u00e5 selvforst\u00e6rkede svingninger:<\/p>\n<ul>\n<li><strong><a href=\"https:\/\/vibromera.eu\/da\/glossary\/oil-whirl\/\">Oliehvirvel<\/a> og oliepisk:<\/strong> de mest almindelige eksempler inden for roterende maskiner. I et v\u00e6skefilmleje tr\u00e6kker den roterende aksel olie ind i en belastningsb\u00e6rende kile. En forstyrrelse kan f\u00e5 selve kilen til at rotere (hvirvle) rundt om lejet; trykket fra den hvirvlende kile skubber til akslen og tilf\u00f8rer dermed yderligere energi til hvirvelen. Den deraf f\u00f8lgende vibration opst\u00e5r ikke ved driftshastigheden, men ved en <a href=\"https:\/\/vibromera.eu\/da\/glossary\/sub-synchronous\/\">subsynkron<\/a> frekvens, typisk 0,42\u20130,48\u00d7 <a href=\"https:\/\/vibromera.eu\/da\/glossary\/running-speed\/\">l\u00f8behastighed<\/a>. Hvis hvirvelfrekvensen \u00e6ndrer sig, s\u00e5 den falder sammen med en rotor <a href=\"https:\/\/vibromera.eu\/da\/glossary\/natural-frequency\/\">naturlig frekvens<\/a>, s\u00e5 tager det fart og udvikler sig til noget langt mere voldsomt <a href=\"https:\/\/vibromera.eu\/da\/glossary\/shaft-whip\/\">pisk<\/a> tilstand.<\/li>\n<li><strong>Chatter ved bearbejdning:<\/strong> Ved drejning eller fr\u00e6sning opst\u00e5r der rysten, n\u00e5r sk\u00e6rev\u00e6rkt\u00f8jet begynder at vibrere. Denne vibration f\u00e5r sp\u00e5ntykkelsen til at variere, og den varierende sp\u00e5ntykkelse f\u00e5r sk\u00e6rekraften til at svinge, og den svingende kraft f\u00f8rer energi tilbage til v\u00e6rkt\u00f8jets vibrationer \u2013 hvilket forst\u00e6rker den til en voldsom, selvforst\u00e6rkende rysten, der \u00f8del\u00e6gger overfladekvaliteten og v\u00e6rkt\u00f8jet.<\/li>\n<li><strong>Aerodynamisk fladder:<\/strong> den koblede b\u00f8jnings- og vridningsvibration i en flyvinge (eller et turbineblad), hvor bev\u00e6gelsen \u00e6ndrer den aerodynamiske profil, den \u00e6ndrede profil \u00e6ndrer lufttrykket, og det \u00e6ndrede tryk tilf\u00f8rer energi tilbage til bev\u00e6gelsen \u2014 hvilket kan f\u00f8re til katastrofalt svigt, hvis det ikke holdes under kontrol.<\/li>\n<li><strong><a href=\"https:\/\/vibromera.eu\/da\/glossary\/rotor-rub\/\">Rotor rubs<\/a>:<\/strong> N\u00e5r en rotor kommer i kontakt med en fast del, opvarmes rotoren lokalt p\u00e5 kontaktstedet p\u00e5 grund af friktionen, hvilket f\u00e5r den til at b\u00f8je sig. B\u00f8jningen \u00f8ger friktionskraften, hvilket igen \u00f8ger varmen og b\u00f8jningen, og der opst\u00e5r dermed en termisk feedback-loop, der kan udvikle sig til en fastl\u00e5sning.<\/li>\n<\/ul>\n<p>To andre v\u00e6skedrevne f\u00e6nomener, der er v\u00e6rd at kende, er <a href=\"https:\/\/vibromera.eu\/da\/glossary\/steam-whirl\/\">damphvirvel<\/a> i turbiner og den bredere gruppe af str\u00f8mningsinducerede ustabiliteter, der skyldes <a href=\"https:\/\/vibromera.eu\/da\/glossary\/aerodynamic-forces\/\">aerodynamiske kr\u00e6fter<\/a>, som begge f\u00f8lger den samme logik med energitilbagemelding.<\/p>\n<h2>3. Selvfremkaldt vs. tvungen vibration \u2013 et overblik<\/h2>\n<table border=\"1\" style=\"width:100%; border-collapse:collapse;\">\n<tr>\n<th>Trait<\/th>\n<th>Tvungen vibration<\/th>\n<th>Selvophidsede vibrationer<\/th>\n<\/tr>\n<tr>\n<td>Drivfrekvens<\/td>\n<td>Indstilles via en ekstern indgang (f.eks. 1\u00d7 ved ubalance)<\/td>\n<td>Fastl\u00e6gges af selve systemet, ofte en egenfrekvens<\/td>\n<\/tr>\n<tr>\n<td>Frekvens kontra hastighed<\/td>\n<td>F\u00f8lger omdrejningshastigheden<\/td>\n<td>K\u00f8rer ofte under synkronhastighed og f\u00f8lger ikke 1\u00d7<\/td>\n<\/tr>\n<tr>\n<td>Amplitudens forl\u00f8b<\/td>\n<td>Stabil, proportional med kraften<\/td>\n<td>Kan vokse ubegr\u00e6nset, indtil der opst\u00e5r en ikke-linearitet<\/td>\n<\/tr>\n<tr>\n<td>Energy source<\/td>\n<td>Den periodiske ydre kraft<\/td>\n<td>En konstant kilde (rotation, str\u00f8mning, sk\u00e6ring), der udnyttes af bev\u00e6gelsen<\/td>\n<\/tr>\n<\/table>\n<h2>4. N\u00f8glekarakteristika og diagnose<\/h2>\n<p>Selvfremkaldte svingninger har en tendens til at efterlade tydelige spor i <a href=\"https:\/\/vibromera.eu\/da\/glossary\/spectrum\/\">FFT-spektrum<\/a>:<\/p>\n<ul>\n<li><strong>Ikke-synkrone frekvenser:<\/strong> Vibrationen er som regel ikke et heltalsmultiplum eller en harmonisk af driftshastigheden. Den ligger typisk p\u00e5 en frekvens under synkronfrekvensen.<\/li>\n<li><strong>Ustabilitet:<\/strong> amplituden kan v\u00e6re meget uregelm\u00e6ssig og kan stige hurtigt ved selv sm\u00e5 \u00e6ndringer i hastighed, temperatur eller belastning.<\/li>\n<li><strong>Sudden onset:<\/strong> Vibrationen kan v\u00e6re helt frav\u00e6rende, indtil maskinen overskrider en bestemt hastigheds- eller belastningst\u00e6rskel \u2014 ofte i forbindelse med en <a href=\"https:\/\/vibromera.eu\/da\/glossary\/critical-speed\/\">kritisk hastighed<\/a> \u2014 hvor den pludselig dukker op med stor styrke.<\/li>\n<\/ul>\n<p>Diagnose indeb\u00e6rer, at man identificerer disse karakteristiske, ikke-synkrone spidser og derefter drager konklusioner om den fysiske mekanisme, der kan for\u00e5rsage en s\u00e5dan ustabilitet i den p\u00e5g\u00e6ldende maskine. Da problemet opst\u00e5r i forbindelse med driftsforholdene, er en optagelse med varierende hastighed s\u00e6rligt oplysende: en <a href=\"https:\/\/vibromera.eu\/da\/glossary\/cascade-plot\/\">Kaskadeplot<\/a> m\u00e5linger foretaget under op- eller nedbremsning viser, at der opst\u00e5r en subsynkron komponent, som derefter l\u00e5ser sig fast p\u00e5 en egenfrekvens, hvilket er det umiskendelige tegn p\u00e5, at hvirvelbev\u00e6gelsen overg\u00e5r til piskbev\u00e6gelse. I tilf\u00e6lde, der skyldes lejer, er en <a href=\"https:\/\/vibromera.eu\/da\/calculators\/journal-bearing-frequencies\/\">beregner for glidelejers fejlfrekvenser<\/a> hj\u00e6lper med at fastsl\u00e5, om en mist\u00e6nkelig spids ligger inden for oliesvirvelb\u00e5ndet. Samlebetegnelsen for hele dette f\u00e6nomen er <a href=\"https:\/\/vibromera.eu\/da\/glossary\/rotor-instability\/\">rotorinstabilitet<\/a>, og at skelne dette fra en tvungen respons er analytikerens f\u00f8rste og vigtigste afg\u00f8relse \u2014 for l\u00f8sningen er helt anderledes: tvungne vibrationer reduceres ved afbalancering eller justering, mens en selvforst\u00e6rket ustabilitet skal fjernes ved at \u00e6ndre lejets geometri, spillerum, belastning eller d\u00e6mpning.<\/p>\n<h2>5. Hvorfor det ikke kan udlignes<\/h2>\n<p>Fysikken giver os en konkret advarsel. Da en selvexciteret vibration ikke skyldes en roterende tung plet, kan den ikke afhj\u00e6lpes ved at tilf\u00f8je korrektionsv\u00e6gte \u2014 energien leveres nemlig af lejev\u00e6sken, sk\u00e6reprocessen eller luftstr\u00f8mmen, ikke af en masseubalance. Netop derfor er det vigtigt at foretage en omhyggelig m\u00e5ling p\u00e5 stedet, inden der iv\u00e6rks\u00e6ttes afhj\u00e6lpende foranstaltninger: N\u00e5r en tekniker m\u00e5ler amplitude og fase med en b\u00e6rbar tokanalsanalysator som f.eks. <a href=\"https:\/\/vibromera.eu\/da\/vare-2\/balanset-1\/\">Balanset-1A<\/a>, peger en stabil, gentagelig 1\u00d7-vektor p\u00e5 et egentligt balanceringsproblem, mens en svingende, sub-synkron, ikke-gentagelig komponent er et advarselssignal om, at fejlen skyldes ustabilitet, og at balancering ville v\u00e6re spild af kr\u00e6fter. Ved at l\u00e6se <a href=\"https:\/\/vibromera.eu\/da\/glossary\/vibration-analyzer\/\">analysator<\/a> ... forhindrer dermed den klassiske fejl, hvor man fors\u00f8ger at udligne en <a href=\"https:\/\/vibromera.eu\/da\/glossary\/whirl\/\">hvirvel<\/a>.<\/p>\n<hr>\n<p><a href=\"https:\/\/vibromera.eu\/da\/glossary\/\">\u2190 Tilbage til hovedindekset<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>En forklaring af selvexciteret vibration, en farlig type vibration, hvor selve bev\u00e6gelsen skaber de kr\u00e6fter, der opretholder eller forst\u00e6rker vibrationen, s\u00e5som oliehvirvel og vibrationer.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[109,110],"tags":[],"class_list":["post-230","glossary","type-glossary","status-publish","hentry","category-glossary","category-vibration-diagnostics"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/glossary\/230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/glossary"}],"about":[{"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/types\/glossary"}],"version-history":[{"count":1,"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/glossary\/230\/revisions"}],"predecessor-version":[{"id":101308,"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/glossary\/230\/revisions\/101308"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/media?parent=230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/categories?post=230"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/da\/wp-json\/wp\/v2\/tags?post=230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}