{"id":1242,"date":"2026-04-02T03:08:14","date_gmt":"2026-04-02T03:08:14","guid":{"rendered":"https:\/\/planetarygeardrive.top\/?p=1242"},"modified":"2026-04-02T03:12:09","modified_gmt":"2026-04-02T03:12:09","slug":"how-to-read-a-planetary-gearbox-part-number","status":"publish","type":"post","link":"https:\/\/planetarygeardrive.top\/th\/application\/how-to-read-a-planetary-gearbox-part-number\/","title":{"rendered":"How to Read a Planetary Gearbox Part Number"},"content":{"rendered":"<p><!-- Group : Industry Applications Title : Planetary Gearbox for Winch Drives: Selection Guide for Marine and Construction Applications Core KW : planetary gearbox winch drive Long-tail : \"winch drive planetary gearbox marine\" \"planetary gearbox crane winch selection\" \"FEM rated winch gearbox supplier\" \"hydraulic winch drive planetary reducer\" Anchor 1 : inline planetary gearbox range \u2192 \/inline-planetary-gearbox\/ Anchor 2 : full product range \u2192 \/planetary-gearboxes\/ --><\/p>\n<div style=\"background: #f4f7f9; border-left: 4px solid #245273; padding: 18px 22px; border-radius: 0 8px 8px 0; margin-bottom: 28px; box-sizing: border-box; word-break: break-word; overflow-wrap: break-word;\">\n<p style=\"font-size: 15px; color: #333; line-height: 1.8; margin: 0;\">The <strong>planetary gearbox for winch drives<\/strong> carries a design requirement that most industrial gearbox applications do not: the load it holds is suspended. A conveyor drive failure stops production. A winch drive failure may drop a load. This changes the engineering conversation from performance optimisation to safety factor and fail-safe design from the first line of the specification. This guide covers the selection criteria for marine and construction winch drives \u2014 from torque sizing through to brake specification and DNV certification requirements for offshore equipment procurement.<\/p>\n<\/div>\n<h2 style=\"font-size: 20px; font-weight: 800; color: #245273; padding-left: 12px; border-left: 4px solid #e4cd97; margin: 0 0 14px;\">Why Planetary Gearboxes Are Specified for Winch Drives<\/h2>\n<p style=\"font-size: 15px; color: #333; line-height: 1.8; margin: 0 0 14px; word-break: break-word; overflow-wrap: break-word;\">Three characteristics make planetary gearboxes the standard drive solution for rope drum winches in marine and construction applications:<\/p>\n<ul style=\"padding-left: 20px; margin: 0 0 14px; font-size: 15px; color: #333; line-height: 1.9;\">\n<li><strong>Coaxial drum mounting:<\/strong> In a planetary winch gearbox, the drum mounts directly on the output face of the unit \u2014 the drum and planetary housing share the same centreline. This eliminates the need for a separate coupling shaft and allows the entire motor-gearbox-drum assembly to be mounted on a compact baseplate.<\/li>\n<li><strong>High torque density:<\/strong> At the torque ratings required for medium to large winches (10,000\u2013280,000 Nm), a planetary gearbox is substantially more compact than a helical or worm alternative. This matters on marine deck equipment where deck space and structural deadweight are both at a premium.<\/li>\n<li><strong>Integrated brake compatibility:<\/strong> Most winch duty planetary gearboxes are designed to accept an integrated negative (spring-applied) multi-disc brake between the gearbox and the drum. This brake engages automatically on power loss \u2014 a mandatory feature for any load-holding winch application.<\/li>\n<\/ul>\n<h2 style=\"font-size: 20px; font-weight: 800; color: #245273; padding-left: 12px; border-left: 4px solid #e4cd97; margin: 0 0 14px;\">Key Specification Parameters for Winch Drive Gearboxes<\/h2>\n<div style=\"overflow-x: auto; border-radius: 9px; border: 1px solid #dde3e8; margin-bottom: 28px;\">\n<table style=\"width: 100%; border-collapse: collapse; font-size: 14px; min-width: 420px;\">\n<thead>\n<tr style=\"background: #245273;\">\n<th style=\"padding: 10px 14px; text-align: left; color: #fff; font-size: 12px; font-weight: bold; letter-spacing: .07em; text-transform: uppercase; width: 32%;\">Parameter<\/th>\n<th style=\"padding: 10px 14px; text-align: left; color: #fff; font-size: 12px; font-weight: bold; letter-spacing: .07em; text-transform: uppercase;\">How to Determine It<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background: #fff;\">\n<td style=\"padding: 9px 14px; font-weight: bold; color: #245273; border-bottom: 1px solid #dde3e8;\">Line pull (kN)<\/td>\n<td style=\"padding: 9px 14px; color: #333; border-bottom: 1px solid #dde3e8; word-break: break-word;\">Maximum load to be lifted or pulled. Include dynamic load factor (typically 1.25\u20131.5\u00d7 static load for marine applications per DNV guidelines).<\/td>\n<\/tr>\n<tr style=\"background: #f4f7f9;\">\n<td style=\"padding: 9px 14px; font-weight: bold; color: #245273; border-bottom: 1px solid #dde3e8;\">Drum torque (Nm)<\/td>\n<td style=\"padding: 9px 14px; color: #333; border-bottom: 1px solid #dde3e8; word-break: break-word;\">Line pull \u00d7 drum radius (at maximum rope layer). Use outer drum radius (maximum rope layer) to get worst-case torque.<\/td>\n<\/tr>\n<tr style=\"background: #fff;\">\n<td style=\"padding: 9px 14px; font-weight: bold; color: #245273; border-bottom: 1px solid #dde3e8;\">Gear ratio<\/td>\n<td style=\"padding: 9px 14px; color: #333; border-bottom: 1px solid #dde3e8; word-break: break-word;\">Required drum RPM at rated line speed. Divide motor RPM by drum RPM. For hydraulic motors at 1,500 RPM and drum at 10 RPM: ratio = 150:1.<\/td>\n<\/tr>\n<tr style=\"background: #fff;\">\n<td style=\"padding: 9px 14px; font-weight: bold; color: #245273; border-bottom: 1px solid #dde3e8;\">Brake holding torque<\/td>\n<td style=\"padding: 9px 14px; color: #333; border-bottom: 1px solid #dde3e8; word-break: break-word;\">Minimum 1.5\u00d7 maximum drum torque. For FEM M5 crane duty, typically 2\u00d7 drum torque. Must be specified as a static holding requirement, not a dynamic stopping requirement.<\/td>\n<\/tr>\n<tr style=\"background: #f4f7f9;\">\n<td style=\"padding: 9px 14px; font-weight: bold; color: #245273; border-bottom: 1px solid #dde3e8;\">Duty classification<\/td>\n<td style=\"padding: 9px 14px; color: #333; border-bottom: 1px solid #dde3e8; word-break: break-word;\">FEM classification (M1\u2013M8) or ISO 4301 group (1Am to 8). Determines the service factor to apply and influences bearing life calculation.<\/td>\n<\/tr>\n<tr style=\"background: #fff;\">\n<td style=\"padding: 9px 14px; font-weight: bold; color: #245273;\">Certification required<\/td>\n<td style=\"padding: 9px 14px; color: #333; word-break: break-word;\">DNV type approval, ABS PDA, LR, BV, or other classification society. Required for offshore deck equipment and crane units on classed vessels.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2 style=\"font-size: 20px; font-weight: 800; color: #245273; padding-left: 12px; border-left: 4px solid #e4cd97; margin: 0 0 14px;\">Negative Multi-Disc Brake: What It Is and Why It Cannot Be Omitted<\/h2>\n<p style=\"font-size: 15px; color: #333; line-height: 1.8; margin: 0 0 14px; word-break: break-word; overflow-wrap: break-word;\">A <strong>negative (spring-applied) multi-disc brake<\/strong> is spring-loaded to the engaged (braking) position. Hydraulic or electrical pressure is required to release it for normal operation. When power is lost \u2014 intentionally or by system failure \u2014 the springs re-engage the brake automatically, holding the drum at its current position.<\/p>\n<p style=\"font-size: 15px; color: #333; line-height: 1.8; margin: 0 0 14px; word-break: break-word; overflow-wrap: break-word;\">This is functionally the opposite of a positive brake, which requires power to engage. A positive brake on a winch would release the load on power failure \u2014 the most dangerous possible failure mode for a suspended load application. This is why negative brakes are mandatory on any winch that holds loads in suspension, and why no specification for a crane, hoist, anchor windlass, or mooring winch should be accepted without explicit confirmation of the negative brake type.<\/p>\n<p style=\"font-size: 15px; color: #333; line-height: 1.8; margin: 0 0 28px; word-break: break-word; overflow-wrap: break-word;\">Our winch drive planetary gearbox series includes an integrated negative multi-disc brake as a standard configurable option. Brake holding torque can be specified from 1.0\u00d7 to 3.0\u00d7 rated drum torque depending on the duty classification and safety factor requirements of the application. The brake release pressure or voltage is specified at the time of order to match the machine’s existing hydraulic or electrical circuit.<\/p>\n<h2 style=\"font-size: 20px; font-weight: 800; color: #245273; padding-left: 12px; border-left: 4px solid #e4cd97; margin: 0 0 14px;\">Marine vs Construction Winch: What Changes in the Specification<\/h2>\n<div style=\"display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 28px;\">\n<div style=\"box-sizing: border-box; width: 100%; max-width: 420px; background: #f4f7f9; border: 1px solid #dde3e8; border-radius: 9px; padding: 18px; word-break: break-word; overflow-wrap: break-word;\">\n<div style=\"font-size: 14px; font-weight: 800; color: #245273; margin-bottom: 8px;\">Marine Deck Winches<\/div>\n<p style=\"font-size: 13px; color: #555; line-height: 1.65; margin: 0;\">DNV type approval or equivalent classification society certificate is typically mandatory. IP67 minimum \u2014 often IP68 for deck-mounted equipment on vessels operating in high sea states. Salt spray corrosion resistance requires external paint specification alongside IP rating. Hydraulic motor input is standard; electric motor input for mooring winches on larger vessels. Stainless shaft sealing and bearing protection required for prolonged saltwater exposure.<\/p>\n<\/div>\n<div style=\"box-sizing: border-box; width: 100%; max-width: 420px; background: #f4f7f9; border: 1px solid #dde3e8; border-radius: 9px; padding: 18px; word-break: break-word; overflow-wrap: break-word;\">\n<div style=\"font-size: 14px; font-weight: 800; color: #245273; margin-bottom: 8px;\">Construction Crane Winch Drives<\/div>\n<p style=\"font-size: 13px; color: #555; line-height: 1.65; margin: 0;\">FEM duty classification governs service factor. IP65 typically sufficient for covered crane housings; IP67 for outdoor tower cranes exposed to rain. Classification society certification generally not required unless the crane is operating on a jetty or vessel. IEC electric motor input is standard for fixed cranes; hydraulic input for mobile crane-mounted winches.<\/p>\n<\/div>\n<\/div>\n<h2 style=\"font-size: 20px; font-weight: 800; color: #245273; padding-left: 12px; border-left: 4px solid #e4cd97; margin: 0 0 14px;\">Our Winch Drive Gearbox Range<\/h2>\n<p style=\"font-size: 15px; color: #333; line-height: 1.8; margin: 0 0 14px; word-break: break-word; overflow-wrap: break-word;\">Our PWD, RCW, SLW, and SMW series winch drive planetary gearboxes cover output torque from 1,000 Nm to 280,000 Nm. Standard models carry FEM M5 duty rating and IP67 sealing. DNV type approval units are available from the SMW series upward. All winch series include the negative multi-disc brake as a standard configurable option.<\/p>\n<p style=\"font-size: 15px; color: #333; line-height: 1.8; margin: 0 0 28px; word-break: break-word; overflow-wrap: break-word;\">Browse the <a style=\"color: #245273; font-weight: bold;\" href=\"https:\/\/planetarygeardrive.top\/th\/inline-planetary-gearbox\/\">inline planetary gearbox<\/a> series \u2014 which includes the coaxial winch drive configurations \u2014 and the full <a style=\"color: #245273; font-weight: bold;\" href=\"https:\/\/planetarygeardrive.top\/th\/planetary-gearboxes\/\">planetary gearbox product range<\/a> including slewing, track, and wheel drive series. For winch drive projects requiring DNV certification documentation, contact <a href=\"mailto:sales@planetarygeardrive.top\"><strong>sales@planetarygeardrive.top<\/strong> <\/a>with your line pull, drum diameter, duty classification, and certification requirement. Formal quotation with certification confirmation within 24 hours.<\/p>\n<div style=\"background: #f4f7f9; border: 1px solid #dde3e8; border-radius: 8px; padding: 12px 15px; word-break: break-word; overflow-wrap: break-word;\">\n<p style=\"font-size: 11px; font-weight: bold; letter-spacing: .1em; text-transform: uppercase; color: #999; margin: 0 0 5px;\">Related Searches<\/p>\n<p style=\"font-size: 12px; color: #999; margin: 0; line-height: 1.85;\">planetary gearbox winch drive \u00a0\u00b7\u00a0 marine winch gearbox DNV certified \u00a0\u00b7\u00a0 crane winch planetary reducer \u00a0\u00b7\u00a0 hydraulic winch drive gearbox supplier \u00a0\u00b7\u00a0 negative brake winch gearbox \u00a0\u00b7\u00a0 FEM M5 winch gearbox selection<\/p>\n<p style=\"font-size: 12px; color: #999; margin: 0; line-height: 1.85; text-align: right;\">editor\uff1aWM<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>The planetary gearbox for winch drives carries a design requirement that most industrial gearbox applications do not: the load it holds is suspended. A conveyor drive failure stops production. A winch drive failure may drop a load. This changes the engineering conversation from performance optimisation to safety factor and fail-safe design from the first line [&hellip;]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[2116],"tags":[17,2120],"class_list":["post-1242","post","type-post","status-publish","format-standard","hentry","category-industry-applications","tag-planetary-gearbox","tag-planetary-gearbox-part-number-guide"],"_links":{"self":[{"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/posts\/1242","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/comments?post=1242"}],"version-history":[{"count":2,"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/posts\/1242\/revisions"}],"predecessor-version":[{"id":1244,"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/posts\/1242\/revisions\/1244"}],"wp:attachment":[{"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/media?parent=1242"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/categories?post=1242"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/planetarygeardrive.top\/th\/wp-json\/wp\/v2\/tags?post=1242"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}