{"id":3415,"date":"2025-07-07T10:10:41","date_gmt":"2025-07-07T02:10:41","guid":{"rendered":"https:\/\/taichungbro.com\/?p=3415"},"modified":"2025-07-07T10:12:02","modified_gmt":"2025-07-07T02:12:02","slug":"ball-roller-screw","status":"publish","type":"post","link":"https:\/\/www.taichungbro.com\/en\/2025\/07\/07\/ball-roller-screw\/","title":{"rendered":"How to choose between ball screws and roller screws? Three key indicators: lifespan, efficiency, and preload."},"content":{"rendered":"<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><h2>Table of Content<\/h2><nav><ul><li class=\"\"><a href=\"#\u6efe\u73e0-vs-\u6efe\u67f1\uff1a\u5de5\u4f5c\u539f\u7406\u8207\u7d50\u69cb\u5dee\u7570\">Ball bearings vs. roller bearings: differences in working principles and structures<\/a><\/li><li class=\"\"><a href=\"#\u6027\u80fd\u6bd4\u8f03\uff1a\u6548\u7387\u3001\u901f\u5ea6\u8207\u8ca0\u8f09\u66f2\u7dda\">Performance Comparison: Efficiency, Speed, and Load Curves<\/a><\/li><li class=\"\"><a href=\"#\u58fd\u547d\u8207\u8010\u4e45\u6027\uff1a\u63a5\u89f8\u75b2\u52de\u8207\u6f64\u6ed1\u7b56\u7565\">Lifespan and Durability: Contact Fatigue and Lubrication Strategies<\/a><\/li><li class=\"\"><a href=\"#\u9810\u58d3\u8a2d\u5b9a\u8207\u525b\u6027\u512a\u5316\uff1a\u7bc4\u4f8b\u8207\u5e38\u898b\u8aa4\u5340\">Preload setting and stiffness optimization: Examples and common misconceptions<\/a><\/li><li class=\"\"><a href=\"#\u9078\u578b\u6d41\u7a0b\u8207\u61c9\u7528\u6848\u4f8b\">Selection Process and Application Cases<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<p class=\"wp-block-paragraph\">In precision transmission systems, ball screws and roller screws are often discussed side-by-side, but they differ significantly in thread contact type, load-bearing mechanism, and preload method. Choosing based solely on a single metric like &quot;accuracy&quot; or &quot;lifespan&quot; can easily overlook crucial variables such as actual load, dynamic rigidity, and lubrication maintenance, leading to a substantial increase in cost and downtime risk only after mass production. We will analyze the differences in speed, rigidity, efficiency, and durability between the two types of screws using a logical approach: working principle \u2192 performance comparison \u2192 lifespan calculation \u2192 preload setting \u2192 practical selection. Combining measured load curves and L10 lifespan calculation examples, we will provide directly applicable preload setting and selection processes to help designers shorten development time while achieving optimal cost-effectiveness.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u6efe\u73e0-vs-\u6efe\u67f1\uff1a\u5de5\u4f5c\u539f\u7406\u8207\u7d50\u69cb\u5dee\u7570\">Ball bearings vs. roller bearings: differences in working principles and structures<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Ball screws circulate steel balls in the thread grooves through &quot;point contact,&quot; resulting in low friction and high efficiency, but point contact can easily lead to localized stress concentration. Roller screws, on the other hand, utilize multiple rollers in &quot;line contact&quot; to simultaneously bear the load with the screw, significantly increasing the contact area and allowing for higher axial loads with the same outer diameter. Planetary roller screws have a complex roller circulation mechanism, requiring higher manufacturing precision, which increases cost and maintenance complexity. Structurally:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Loop method:<\/strong>The ball bearings are circulated through the return pipe or end cap, and the rollers are guided by planetary tooth grooves.<\/li>\n\n\n\n<li><strong>Contact wire length<\/strong>Roller &gt; Ball \u2192 Can disperse contact stress.<\/li>\n\n\n\n<li><strong>Permissible speed<\/strong>Because ball bearings are lighter and have less centrifugal force, their limiting dn value (diameter \u00d7 rotational speed) is usually higher than that of roller bearings.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u6027\u80fd\u6bd4\u8f03\uff1a\u6548\u7387\u3001\u901f\u5ea6\u8207\u8ca0\u8f09\u66f2\u7dda\">Performance Comparison: Efficiency, Speed, and Load Curves<\/h2>\n\n\n\n<figure class=\"wp-block-table aligncenter\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">index<\/th><th>ball screw<\/th><th>roller screw<\/th><th>Practical impact<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\">Theoretical efficiency<\/td><td>90 \u2013 95% <a href=\"https:\/\/kaiwoleadscrew.com\/why-ball-screw-efficiency-matters-more-today\/?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noreferrer noopener\">kaiwoleadscrew.com<\/a><br><a href=\"https:\/\/www.rollco.se\/storage\/34B43AD42DB8E5D97AF0AD8BCA359B229E82189496BC207367DA0174CB701A8D\/ee88dd8f1de24283a60057d3b4bdf92b\/pdf\/media\/445f4cb485944d31bae5236ba0e44643\/Ball_Screws_Technical_Information.pdf?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noreferrer noopener\">rollco.se<\/a><\/td><td>Approximately 80-90 TP3T (common value 851 TP3T) <a href=\"https:\/\/www.tolomatic.com\/info-center\/resource-details\/acme-ball-roller-screw-selection\/?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noreferrer noopener\">tolomatic.com<\/a><br><a href=\"https:\/\/www.powerjacks.com\/perch\/resources\/brochure\/pjb-prs-spiracon-en.pdf?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noreferrer noopener\">powerjacks.com<\/a><\/td><td>Affecting drive motor torque and heat generation<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Dynamic load rating (Ca)<\/td><td>Lower for the same diameter<\/td><td>Increased by 1.5 to 3 times for the same diameter. <a href=\"https:\/\/www.machinedesign.com\/mechanical-motion-systems\/article\/21175536\/whats-the-difference-between-roller-and-ball-screws?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noreferrer noopener\">machinedesign.com<\/a> \/ <a href=\"https:\/\/www.moog.com\/news\/ideas-in-motion-control\/2004\/08\/selection-of-ball-screw-versus-roller-screw-technologies.html?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noreferrer noopener\">moog.com<\/a><\/td><td>Related to lifespan and frame size<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Permissible maximum speed<\/td><td>High (dn can reach 120,000)<\/td><td>(DN approximately 80,000)<\/td><td>High-speed positioning equipment should prioritize ball bearings.<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Back gap range<\/td><td>0 \u2013 0.03 mm adjustable<\/td><td>It can achieve near-zero backlash, but the adjustment is complex.<\/td><td>Affects repeatability accuracy<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\">Costs (including maintenance)<\/td><td>\u4e2d<\/td><td>\u9ad8<\/td><td>Initial CAPEX and Spare Parts Inventory<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<ul class=\"wp-block-list\">\n<li>A higher dynamic load rating indicates a longer lifespan or the ability to use a smaller diameter for the same workload.<\/li>\n\n\n\n<li>Higher efficiency means less motor torque is required for the same thrust, saving energy and reducing heat generation.<\/li>\n<\/ul>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u58fd\u547d\u8207\u8010\u4e45\u6027\uff1a\u63a5\u89f8\u75b2\u52de\u8207\u6f64\u6ed1\u7b56\u7565\">Lifespan and Durability: Contact Fatigue and Lubrication Strategies<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Screw life is often measured in terms of <strong>L10<\/strong>(90% Reliability) Calculation: <\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\"><em>L<sub>10<\/sub><\/em> = ( <em>C<sub>a<\/sub><\/em> \/ <em>P<\/em> ) x 10<sup>6<\/sup> revs<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">in <em>C<sub>a<\/sub><\/em>For the basic rated dynamic load,<em>P<\/em>This is the equivalent working load. Roller screws have a long contact line and a large number of rollers.<em>C<sub>a<\/sub><\/em>Significantly higher than ball screws of the same size, therefore...<strong>High load, long stroke<\/strong>Applications such as electric injection molding machine clamping and aerospace test platforms are particularly sought after.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Lubrication key<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ball screw: Low viscosity grease is required at high speeds to reduce centrifugal slinging; it is recommended to regrease every 300 km or every 3-6 months.<\/li>\n\n\n\n<li>Roller screws: They have a large contact area and disperse the load pressure, so the requirements for oil film thickness are slightly lower; however, due to the large number of rollers, the oil circuit resistance is high, and the lubrication channel design must be fully ensured.<\/li>\n\n\n\n<li>Using NLGI #1 \u2013 #2 lithium-based or complex lithium-based grease can cover the 80% operating conditions. If the ambient temperature is &gt; 80 \u00b0C, it is recommended to use synthetic ester-based grease and evaluate the forced circulation oil circuit.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u9810\u58d3\u8a2d\u5b9a\u8207\u525b\u6027\u512a\u5316\uff1a\u7bc4\u4f8b\u8207\u5e38\u898b\u8aa4\u5340\">Preload setting and stiffness optimization: Examples and common misconceptions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Appropriate preload helps eliminate backlash and improve dynamic stiffness, but excessive preload increases friction and thermal expansion. The industry generally uses...<strong>Basic rated dynamic load C<\/strong>The percentage setting of the pre-pressure (F\u209a).<\/p>\n\n\n\n<figure class=\"wp-block-table aligncenter\"><table class=\"has-fixed-layout\"><thead><tr><th>Precompression rating (F\u209a\/C)<\/th><th>Recommended application<\/th><th>Rigidity Enhancement<\/th><th>Possible side effects<\/th><\/tr><\/thead><tbody><tr><td>0.02 C<\/td><td>Precision exposure machine, laser cutting<\/td><td>+20%<\/td><td>Lower back clearance, weaker vibration resistance<\/td><\/tr><tr><td>0.05 C<\/td><td>CNC machining center, grinding machine<\/td><td>+35%<\/td><td>Increased fever requires monitoring of temperature rise.<\/td><\/tr><tr><td>0.10 C<\/td><td>High clamping force injection molding machine, die casting machine<\/td><td>+50%<\/td><td>The torque has increased significantly, requiring the use of a high-power servo motor.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Common Misconceptions<\/strong><\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Focusing solely on positioning accuracy while ignoring thermal displacement: The idea that the greater the preload, the better is a misconception. Long strokes should be equipped with cooling or thermal compensation.<\/li>\n\n\n\n<li>The assumption that the same preload can be used universally is incorrect. The rigid gain curves of different leads and different nut structures are very different. When selecting a model, the load spectrum should be recalculated.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"\u9078\u578b\u6d41\u7a0b\u8207\u61c9\u7528\u6848\u4f8b\">Selection Process and Application Cases<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Define working conditions<\/strong>Thrust requirements, stroke, speed, duty cycle rate, and expected life (e.g., 20,000 h).<\/li>\n\n\n\n<li><strong>Calculate the equivalent load P<\/strong>Includes acceleration\/deceleration, impact, and static load.<\/li>\n\n\n\n<li><strong>Preliminary comparison<\/strong>Use the load-speed diagram to quickly determine the feasible diameter of the ball or roller.<\/li>\n\n\n\n<li><strong>Lifespan calculation<\/strong>Substitute<em> C<sub>a<\/sub><\/em>\u3001<em>P<\/em>To the L10 formula; if the lifespan is insufficient, increase the screw diameter or switch to a roller screw.<\/li>\n\n\n\n<li><strong>Optimize preload and lubrication<\/strong>Balance rigidity and heat generation, and then confirm the motor torque margin.<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-table aligncenter\"><table class=\"has-fixed-layout\"><thead><tr><th>Application:Application:<\/th><th>Thrust\/Stroke<\/th><th>Recommended solution<\/th><th>Reasons<\/th><\/tr><\/thead><tbody><tr><td>Electric injection molding machine mold clamping<\/td><td>240 kN \/ 650 mm<\/td><td>Roller screw \u00d880, P=10 mm<\/td><td>High load, low speed, long lifespan<\/td><\/tr><tr><td>Z-axis of a 5-axis machining center<\/td><td>45 kN \/ 600 mm<\/td><td>Ball screw \u00d840, P=10 mm, 0.05 C preload<\/td><td>High-speed positioning and rigid balance required<\/td><\/tr><tr><td>Low Earth Orbit Satellite Antenna Deployment<\/td><td>8 kN \/ 1200 mm<\/td><td>Roller screw \u00d825, P=5 mm, solid lubrication<\/td><td>Vacuum environment, permissible lifespan &gt; 15 years<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Choosing between ball screws and roller screws is not as simple as &quot;choose ball screws for higher efficiency&quot; or &quot;choose roller screws for higher loads.&quot; Designers must consider load spectrum, stroke speed, preload stiffness, life target, lubrication method, and economy, with L10 life and thermal displacement as the final verification basis. If your machine requires high load, high stiffness, and high cycle rate, roller screws can stand out in terms of overall cost-effectiveness; while when pursuing high speed, high efficiency, and low noise, ball screws remain the most competitive solution.<\/p>\n\n\n\n<div style=\"height:var(--wp--preset--spacing--30)\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<h5 class=\"wp-block-heading has-text-align-center\" id=\"\u60f3\u4e86\u89e3\u6709\u95dc\u7ba1\u87ba\u7d0b\u3001\u76f4\u87ba\u7d0b\u3001\u9310\u87ba\u7d0b\u3001\u5c3a\u5bf8\u8868\u793a\u3001\u82f1\u5236\u7ba1\u87ba\u7d0b\u3001\u516c\u5236\u7ba1\u87ba\u7d0b\u7684\u77e5\u8b58\u55ce\uff1f-\u5ef6\u4f38\u95b1\u8b80\uff1a\u300a\u7ba1\u87ba\u7d0b\u767e\u767e\u7a2e-\u4f60\u90fd\u8a8d\u8b58\u55ce-\u300b\">Want to learn about silicone materials, molding, processing, and related knowledge? <br>Further Reading :<a href=\"https:\/\/www.taichungbro.com\/en\/2025\/07\/04\/silicone-rubber\/\" data-type=\"link\" data-id=\"https:\/\/taichungbro.com\/2023\/10\/28\/screw\/\" target=\"_blank\" rel=\"noopener\">Why is silicone rubber hailed as the all-purpose adhesive for manufacturing? Master its 3 key properties.<\/a><\/h5>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity is-style-wide\"\/>\n\n\n\n<div style=\"height:11px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>How to choose between ball screws and roller screws? This article provides a complete analysis from contact type, efficiency, speed, L10 life to 0.02C~0.1C preload examples, with load-speed diagrams and case studies such as high-load injection molding machines. It also compares the applicability of CNC machining, high-speed positioning, long stroke and heavy load scenarios, and provides a guide to lubricant selection.<\/p>","protected":false},"author":2,"featured_media":3417,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[45],"tags":[328,327,331,330,329],"class_list":["post-3415","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industrial-knowledge","tag-328","tag-327","tag-331","tag-330","tag-329"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/posts\/3415","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/comments?post=3415"}],"version-history":[{"count":0,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/posts\/3415\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/media\/3417"}],"wp:attachment":[{"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/media?parent=3415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/categories?post=3415"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.taichungbro.com\/en\/wp-json\/wp\/v2\/tags?post=3415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}