{"id":1489,"date":"2026-07-14T05:54:01","date_gmt":"2026-07-14T05:54:01","guid":{"rendered":"https:\/\/gearrack.top\/product\/double-helical-gear-steel-od-up-to-1370mm-custom-oem\/"},"modified":"2026-07-14T05:54:02","modified_gmt":"2026-07-14T05:54:02","slug":"double-helical-gear-steel-od-up-to-1370mm-custom-oem","status":"publish","type":"product","link":"https:\/\/gearrack.top\/fr\/product\/double-helical-gear-steel-od-up-to-1370mm-custom-oem\/","title":{"rendered":"Engrenage \u00e0 double h\u00e9lice \u2013 Acier, diam\u00e8tre ext\u00e9rieur jusqu'\u00e0 1370 mm, fabrication sur mesure (OEM)"},"content":{"rendered":"<div style=\"font-family:'Helvetica Neue', Arial, sans-serif; color:#1f2937; line-height:1.75; max-width:1200px; margin:0 auto; padding:2%;\">\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:30px;\">Product Overview<\/h2>\n<p><!-- \u4ea7\u54c1600\u00d7600\u4e3b\u56fe \u5de6\uff0c\u9996\u4e24\u6bb5 \u53f3\uff1b\u56fe\u4e0b\u5168\u5bbd\u7eed\u6587 --><\/p>\n<div style=\"display:flex; flex-wrap:wrap; gap:28px; align-items:flex-start; margin:20px 0 0;\">\n<div style=\"flex:0 0 auto; width:100%; max-width:300px;\">\n    <img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1442\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Double-Helical-Gear.webp\" alt=\"Double Helical Gear\" width=\"600\" height=\"600\" style=\"max-width:100%; height:auto; display:block; border-radius:6px; box-shadow:0 2px 10px rgba(26,60,110,0.12);\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Double-Helical-Gear.webp 600w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Double-Helical-Gear-480x480.webp 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) 600px, 100vw\" \/>\n  <\/div>\n<div style=\"flex:1 1 280px; min-width:0;\">\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin-top:0;\">A combination of left-handed and right-handed helical gears with the same twist angle is called a <strong>double helical gear<\/strong>. Double helical gears transmit rotational motion between two parallel shafts. They have all the advantages of helical gears \u2014 strong and quiet \u2014 plus the benefit of cancelling axial thrust forces by combining helical gears with both right- and left-hand twists.<\/p>\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px);\">Double helical gears and herringbone gears are the same types of gear, but those with a groove in the centre are called double helical gears, while those without a groove where the left and right teeth meet are called herringbone gears. Both transmit motion exclusively between <a href=\"https:\/\/gearrack.top\/fr\/product-category\/helical-gear\/\" style=\"color:#1a3c6e; text-decoration:underline;\">parallel shafts<\/a>.<\/p>\n<\/p><\/div>\n<\/div>\n<p><!-- \u56fe\u4e0b\u5168\u5bbd\u7eed\u6587 --><\/p>\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin-top:16px;\">Korea Ever-Power produces double helical gears to customer drawings and sample specifications across a wide range of modules, materials, and accuracy grades. Applications include power generation turbine gearboxes, marine propulsion reduction stages, rolling mill drives, large industrial compressor drives, and high-power cranes. All production ships with full QA documentation: chemical composition report, mechanical performance test, heat treatment record, and dimensional inspection report.<\/p>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Technical Specifications<\/h2>\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px);\">The tables below present the product specifications and production capabilities drawn from the original gear data. Specific dimensions, module, tooth count, helix angle, material, and heat treatment for each order are confirmed against the customer&#8217;s drawing at the quotation stage.<\/p>\n<p><!-- \u4ea7\u54c1\u57fa\u672c\u89c4\u683c\u8868 --><\/p>\n<div style=\"overflow-x:auto; width:100%; margin:16px 0;\">\n<table style=\"width:100%; border-collapse:collapse; font-size:clamp(13px, 1.8vw + 8px, 16px);\">\n<thead>\n<tr style=\"background:#1a3c6e; color:#ffffff;\">\n<th colspan=\"2\" style=\"padding:12px; text-align:center; border:1px solid #1a3c6e; font-size:clamp(14px, 2vw + 8px, 16px);\">Double Helical Gear \u2014 Product Specifications<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1; width:38%;\"><strong>Gear Type<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Double helical gear (with central relief groove) \/ herringbone gear (without groove) \u2014 per customer drawing<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Tooth Shape<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Involute<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Shaft Configuration<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Parallel axis only; external gear<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Helix Angle \u2014 Double Helical<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">20\u00b0 \u2013 45\u00b0 (high helix angle practical due to cancelled axial thrust)<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Helix Angle \u2014 Single Helical (reference)<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">15\u00b0 \u2013 20\u00b0 (limited by axial thrust load on bearings)<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Axial Thrust Force<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Zero (resultant thrust developed in double helical gear is zero; no axial load on bearings; radial force exists as normal)<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Pressure Angle<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">20\u00b0 standard; other angles per customer drawing<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Bearing Span<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Longer than single helical gear \u2014 due to central relief groove between two helical faces<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Power Capacity<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Higher than single helical gear for identical size and module; suitable for cranes, marine drives, turbines<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Efficiency<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Higher than single helical gear; higher than spur gear and worm gear<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Gear Alignment Requirement<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Precise alignment required \u2014 misalignment prevents full thrust cancellation and causes uneven load distribution<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Material \u2014 Standard<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">20CrMnTi, 42CrMo, 40Cr, 20CrNiMo, 18CrNiMo6, 45# carbon steel, cast iron, stainless steel 304\/316<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Heat Treatment<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Carburising &amp; quenching, through-hardening &amp; tempering, nitriding, induction hardening, normalising<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Surface Hardness<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">58\u201362 HRC (carburised); 280\u2013340 HB (through-hardened); per heat treatment route and material<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Gear Process<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Forging \u2192 turning \u2192 hobbing \u2192 heat treatment \u2192 external grinding \u2192 tooth grinding (per accuracy grade)<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Tooth Finishing<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Hobbed, shaved, or ground \u2014 per accuracy grade and application<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Accuracy Standard<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">ISO, DIN 3962, AGMA, JIS, GB \u2014 per customer drawing; DIN 6 standard for high-power turbine\/marine applications<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Surface Treatment<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Phosphating, black oxide, zinc plating, passivation, as-machined<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>Mounting<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Keyed bore, spline bore, interference fit, or flanged \u2014 per customer specification<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>QA Documentation<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Chemical composition report, mechanical performance report, heat treatment curve, dimensional inspection report; UT (EN 10228-3 \/ SA388) available<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:10px; border:1px solid #cbd5e1;\"><strong>OEM \/ ODM<\/strong><\/td>\n<td style=\"padding:10px; border:1px solid #cbd5e1;\">Full service; customer drawings, worn samples, and reverse engineering accepted<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><!-- \u52a0\u5de5\u80fd\u529b\u89c4\u683c\u8868 --><\/p>\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin-top:24px; margin-bottom:8px;\"><strong>Gear \/ Spline Production Capabilities<\/strong><\/p>\n<div style=\"overflow-x:auto; width:100%; margin:0 0 16px;\">\n<table style=\"width:100%; border-collapse:collapse; font-size:clamp(12px, 1.6vw + 8px, 14px);\">\n<thead>\n<tr style=\"background:#1a3c6e; color:#ffffff;\">\n<th style=\"padding:10px 12px; text-align:left; border:1px solid #1a3c6e; min-width:160px;\">External Gears &amp; Splines<\/th>\n<th style=\"padding:10px 12px; text-align:center; border:1px solid #1a3c6e;\">Hobbing<\/th>\n<th style=\"padding:10px 12px; text-align:center; border:1px solid #1a3c6e;\">Milling<\/th>\n<th style=\"padding:10px 12px; text-align:center; border:1px solid #1a3c6e;\">Tooth Grinding<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum O.D.<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum Face Width<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum Module<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">45 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>AGMA \/ DIN Level<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">DIN Class 8<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">DIN Class 8<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">DIN Class 4<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Tooth Surface Finish<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">Ra 0.6<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum Helix Angle<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">\u00b145\u00b0<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">\u00b122.5\u00b0<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">\u00b145\u00b0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div style=\"overflow-x:auto; width:100%; margin:0 0 16px;\">\n<table style=\"width:100%; border-collapse:collapse; font-size:clamp(12px, 1.6vw + 8px, 14px);\">\n<thead>\n<tr style=\"background:#1a3c6e; color:#ffffff;\">\n<th style=\"padding:10px 12px; text-align:left; border:1px solid #1a3c6e; min-width:160px;\">Internal Gears &amp; Splines<\/th>\n<th style=\"padding:10px 12px; text-align:center; border:1px solid #1a3c6e;\">Milling<\/th>\n<th style=\"padding:10px 12px; text-align:center; border:1px solid #1a3c6e;\">Shaping<\/th>\n<th style=\"padding:10px 12px; text-align:center; border:1px solid #1a3c6e;\">Tooth Grinding<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum O.D.<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Minimum I.D.<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">650 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">50 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">100 mm<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum Face Width<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum Module<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">45 mm<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>AGMA \/ DIN Level<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">DIN Class 8<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">DIN Class 8<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">DIN Class 4<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Tooth Surface Finish<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">Ra 0.6<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Maximum Helix Angle<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">\u00b122.5\u00b0<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">\u00b122.5\u00b0<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; text-align:center;\">\u00b145\u00b0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Double Helical, Single Helical, and Herringbone \u2014 Key Differences<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1457\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-helical-gear-1.webp\" alt=\"types-of-helical-gear-1\" width=\"1672\" height=\"941\" style=\"max-width:100%; height:auto; display:block; margin:20px auto;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-helical-gear-1.webp 1672w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-helical-gear-1-1280x720.webp 1280w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-helical-gear-1-980x552.webp 980w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-helical-gear-1-480x270.webp 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) and (max-width: 980px) 980px, (min-width: 981px) and (max-width: 1280px) 1280px, (min-width: 1281px) 1672px, 100vw\" \/><\/p>\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px);\">Three related gear forms are commonly grouped together. Understanding the distinctions matters when specifying or sourcing a replacement.<\/p>\n<div style=\"border-left:3px solid #e8a020; padding-left:14px; margin-bottom:13px;\">\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 3px;\"><strong style=\"color:#1a3c6e;\">Single Helical Gear<\/strong><\/p>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; margin:0;\">Teeth inclined in one direction only. Progressive engagement produces smooth, quiet operation but generates sustained axial thrust on shaft bearings. Helix angle limited to 15\u00b0\u201320\u00b0. Suitable for mechanical drives and moderate-power applications; bearing span is shorter than double helical.<\/p>\n<\/div>\n<div style=\"border-left:3px solid #e8a020; padding-left:14px; margin-bottom:13px;\">\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 3px;\"><strong style=\"color:#1a3c6e;\">Double Helical Gear (with central relief groove)<\/strong><\/p>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; margin:0;\">Two helical faces \u2014 identical helix angle, opposite hand \u2014 separated by a machined central groove. Axial thrust cancels completely; no axial load on bearings. Higher helix angles (20\u00b0\u201345\u00b0) are practical. Bearing span is longer due to the central groove. Suitable for high-power cranes, marine drives, and turbines. Precise alignment is required to maintain thrust balance.<\/p>\n<\/div>\n<div style=\"border-left:3px solid #e8a020; padding-left:14px; margin-bottom:16px;\">\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 3px;\"><strong style=\"color:#1a3c6e;\">Herringbone Gear (no central groove)<\/strong><\/p>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; margin:0;\">Identical thrust-cancelling and load-capacity characteristics to double helical, but left-hand and right-hand teeth meet at the centreline without a groove. Maximises effective face width, but requires specialised continuous-cutting equipment. Korea Ever-Power produces both forms to customer drawings.<\/p>\n<\/div>\n<p><!-- \u5355\u53cc\u87ba\u65cb\u5bf9\u6bd4\u8868\uff08\u6765\u81eaCSV\u539f\u6587\u6570\u636e\uff09 --><\/p>\n<div style=\"overflow-x:auto; width:100%; margin:8px 0 0;\">\n<table style=\"width:100%; border-collapse:collapse; font-size:clamp(12px, 1.6vw + 8px, 14px);\">\n<thead>\n<tr style=\"background:#1a3c6e; color:#ffffff;\">\n<th style=\"padding:11px 12px; text-align:left; border:1px solid #1a3c6e; min-width:200px;\">Parameter<\/th>\n<th style=\"padding:11px 12px; text-align:left; border:1px solid #1a3c6e;\">Single Helical Gear<\/th>\n<th style=\"padding:11px 12px; text-align:left; border:1px solid #1a3c6e; background:#1e4d8c;\">Double Helical Gear<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Tooth helix direction<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">One direction only (left-hand or right-hand helix)<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#f0f6ff;\">Two identical gears joined on the same axis \u2014 one left-hand helix, one right-hand helix<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Axial thrust force<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">Develops axial thrust force; exerts load on corresponding bearings; radial force also generated<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#e6f0ff;\"><strong>Resultant thrust force is zero<\/strong> \u2014 no axial load on bearings; radial force exists as normal<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Helix angle range<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">15\u00b0 \u2013 20\u00b0 (limited by axial thrust load)<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#f0f6ff;\"><strong>20\u00b0 \u2013 45\u00b0<\/strong> (high helix angle advantageous due to cancelled thrust)<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Power transmission capacity<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">Comparatively lower<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#e6f0ff;\"><strong>Higher<\/strong> \u2014 can transmit more significant power for identical size and module<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Efficiency<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">Comparatively lower<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#f0f6ff;\"><strong>Higher efficiency<\/strong><\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Bearing span<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">Shorter<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#e6f0ff;\"><strong>Longer<\/strong> \u2014 due to central relief groove between the two helical faces<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Alignment requirement<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">High precision not usually required<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#f0f6ff;\"><strong>Precise alignment required<\/strong> \u2014 misalignment prevents thrust balance and causes vibration<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Co\u00fbt<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">Lower<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#e6f0ff;\">Higher \u2014 design and fabrication are complex and time-consuming<\/td>\n<\/tr>\n<tr style=\"background:#ffffff;\">\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\"><strong>Typical applications<\/strong><\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1;\">Mechanical drives; moderate-power requirements; varied configurations<\/td>\n<td style=\"padding:9px 12px; border:1px solid #cbd5e1; background:#f0f6ff;\"><strong>High-power applications<\/strong>: cranes, marine drives, turbines<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Materials and Heat Treatment<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1387\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-1.webp\" alt=\"Ever-Power workshop 1\" width=\"1402\" height=\"1122\" style=\"max-width:100%; height:auto; display:block; margin:20px auto;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-1.webp 1402w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-1-1280x1024.webp 1280w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-1-980x784.webp 980w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-1-480x384.webp 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) and (max-width: 980px) 980px, (min-width: 981px) and (max-width: 1280px) 1280px, (min-width: 1281px) 1402px, 100vw\" \/><\/p>\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px);\">Korea Ever-Power&#8217;s engineering team specifies the heat treatment route for each order based on load type, speed, and required service life.<\/p>\n<div style=\"border-left:3px solid #1a3c6e; padding-left:14px; margin-bottom:12px;\">\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 3px;\"><strong style=\"color:#1a3c6e;\">Carburising &amp; Quenching \u2014 20CrMnTi, 20CrNiMo, 18CrNiMo6<\/strong><\/p>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; margin:0;\">Standard route for continuous high-load drives. Carbon diffusion to 0.8\u20131.0% followed by quenching produces 58\u201362 HRC case over a tough core. Post-quench tooth grinding corrects heat treatment distortion and delivers the final accuracy grade (typically DIN 6 for turbine and marine applications).<\/p>\n<\/div>\n<div style=\"border-left:3px solid #1a3c6e; padding-left:14px; margin-bottom:12px;\">\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 3px;\"><strong style=\"color:#1a3c6e;\">Through-Hardening &amp; Tempering \u2014 42CrMo, 40Cr, 45#<\/strong><\/p>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; margin:0;\">Uniform 280\u2013340 HB from surface to core. Preferred for large gears where furnace carburising capacity is a constraint, or where field re-machining is required. Used in rolling mill and crane drives where shock impact demands ductility through the full section.<\/p>\n<\/div>\n<div style=\"border-left:3px solid #1a3c6e; padding-left:14px; margin-bottom:0;\">\n<p style=\"font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 3px;\"><strong style=\"color:#1a3c6e;\">Nitriding \u2014 31CrMoV9, Nitriding Steels<\/strong><\/p>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; margin:0;\">For large gears where post-hardening grinding is impractical. Nitriding at 500\u2013580\u00b0C produces 700\u20131000 HV surface hardness with minimal dimensional distortion. The gear is finish-machined to final accuracy before nitriding. Suited to offshore and marine gearboxes where corrosion resistance is also required.<\/p>\n<\/div>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Applications<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1393\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-gears.webp\" alt=\"types of gears\" width=\"1448\" height=\"1086\" style=\"max-width:100%; height:auto; display:block; margin:20px auto;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-gears.webp 1448w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-gears-1280x960.webp 1280w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-gears-980x735.webp 980w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-gears-480x360.webp 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) and (max-width: 980px) 980px, (min-width: 981px) and (max-width: 1280px) 1280px, (min-width: 1281px) 1448px, 100vw\" \/><\/p>\n<div style=\"display:grid; grid-template-columns:repeat(auto-fill, minmax(260px, 1fr)); gap:14px; margin:20px 0;\">\n<div style=\"background:#ffffff; border:1px solid #d1dae8; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<div style=\"font-size:24px; margin-bottom:6px;\">&#9889;<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px, 2vw + 4px, 17px); margin:0 0 6px;\">Power Generation &amp; Turbines<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0;\">Steam turbine and gas turbine reduction gearboxes at very high continuous power. Double helical gears eliminate the thrust bearing stage, reducing losses and maintenance. 20CrNiMo carburised, tooth-ground to DIN 6 accuracy is the standard specification.<\/p>\n<\/p><\/div>\n<div style=\"background:#ffffff; border:1px solid #d1dae8; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<div style=\"font-size:24px; margin-bottom:6px;\">&#9875;<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px, 2vw + 4px, 17px); margin:0 0 6px;\">Marine Propulsion<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0;\">Ship propulsion reduction gearboxes \u2014 among the largest applications for double helical gears. Marine drives require classification society documentation (DNV, ABS, Lloyd&#8217;s Register). Nitrided surfaces improve corrosion resistance in marine atmospheres.<\/p>\n<\/p><\/div>\n<div style=\"background:#ffffff; border:1px solid #d1dae8; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<div style=\"font-size:24px; margin-bottom:6px;\">&#127967;<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px, 2vw + 4px, 17px); margin:0 0 6px;\">Rolling Mills<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0;\">Steel and aluminium rolling mills with frequent load reversals and shock events. Through-hardened 42CrMo at 280\u2013320 HB provides core ductility needed to absorb impact without case spalling.<\/p>\n<\/p><\/div>\n<div style=\"background:#ffffff; border:1px solid #d1dae8; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<div style=\"font-size:24px; margin-bottom:6px;\">&#9935;<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px, 2vw + 4px, 17px); margin:0 0 6px;\">Mining Equipment<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0;\">Bucket wheel excavator drives, conveyor head drives, and ball mill drives requiring continuous high torque with limited maintenance access. Highest available torque density per unit of centre distance.<\/p>\n<\/p><\/div>\n<div style=\"background:#ffffff; border:1px solid #d1dae8; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<div style=\"font-size:24px; margin-bottom:6px;\">&#128167;<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px, 2vw + 4px, 17px); margin:0 0 6px;\">Oil &amp; Gas Compressors<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0;\">Integrally geared centrifugal compressors for gas pipeline and process plant. Zero axial thrust is critical \u2014 the compressor impeller already generates axial thrust, and any additional thrust from gear stages compounds the impeller bearing load.<\/p>\n<\/p><\/div>\n<div style=\"background:#ffffff; border:1px solid #d1dae8; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<div style=\"font-size:24px; margin-bottom:6px;\">&#128736;<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px, 2vw + 4px, 17px); margin:0 0 6px;\">Cranes &amp; Heavy Industrial<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0;\">Large crane hoisting gearboxes, cement mill drives, sugar mill drives, and pump station reduction gears. The axial self-centering property is particularly valuable in long, heavy gearbox shafts subject to thermal expansion.<\/p>\n<\/p><\/div>\n<\/div>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Quality Assurance<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1390\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/measuring-equipment.webp\" alt=\"measuring equipment\" width=\"1536\" height=\"1024\" style=\"max-width:100%; height:auto; display:block; margin:20px auto;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/measuring-equipment.webp 1536w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/measuring-equipment-1280x853.webp 1280w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/measuring-equipment-980x653.webp 980w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/measuring-equipment-480x320.webp 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) and (max-width: 980px) 980px, (min-width: 981px) and (max-width: 1280px) 1280px, (min-width: 1281px) 1536px, 100vw\" \/><\/p>\n<ol style=\"font-size:clamp(14px, 2vw + 10px, 16px); padding-left:20px; line-height:1.9; margin-bottom:0;\">\n<li style=\"margin-bottom:5px;\"><strong>Chemical composition report<\/strong> \u2014 mill certificate and spectral analysis confirming the alloy grade before any machining begins.<\/li>\n<li style=\"margin-bottom:5px;\"><strong>Mechanical performance report<\/strong> \u2014 tensile strength, yield strength, elongation, and Charpy impact energy from test pieces in the same heat as production parts.<\/li>\n<li style=\"margin-bottom:5px;\"><strong>Ultrasonic test (UT) report<\/strong> \u2014 100% volumetric UT per EN 10228-3 or SA388, performed on the blank before gear cutting. Selectable option; standard for turbine and marine applications.<\/li>\n<li style=\"margin-bottom:5px;\"><strong>Heat treatment record<\/strong> \u2014 original time-temperature curves from carburising, quenching, and tempering furnace runs, retained per batch.<\/li>\n<li style=\"margin-bottom:0;\"><strong>Dimensional inspection report<\/strong> \u2014 CMM verification of tooth spacing error, profile form, helix angle, pitch diameter, bore, OD, face width, and central groove dimensions. Angular alignment between the two helical faces is verified to confirm correct helix angle opposition.<\/li>\n<\/ol>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Frequently Asked Questions<\/h2>\n<div style=\"margin-top:20px;\">\n<div style=\"margin-bottom:20px;\">\n<p style=\"color:#1a3c6e; font-weight:700; margin-bottom:6px; font-size:clamp(15px, 2vw + 10px, 17px);\">If the axial thrust cancels internally, why do double helical gears still require precise alignment?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px, 2vw + 10px, 16px);\">The thrust cancellation depends on both helical faces being equally and correctly loaded. If misaligned, one face carries more load than the other \u2014 cancellation is incomplete and a net axial force develops. More critically, misalignment shifts the tooth contact zone toward one edge of each face, concentrating stress and initiating pitting at a fraction of the design torque. Alignment requirements are therefore more stringent for double helical gears, not less, because optimal performance depends on symmetric loading of both tooth faces simultaneously.<\/p>\n<\/div>\n<hr style=\"border:none; border-top:1px dashed #cbd5e1; margin:16px 0;\">\n<div style=\"margin-bottom:20px;\">\n<p style=\"color:#1a3c6e; font-weight:700; margin-bottom:6px; font-size:clamp(15px, 2vw + 10px, 17px);\">What are the consequences of incorrect central groove dimensions?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px, 2vw + 10px, 16px);\">The groove provides runout space for the cutting tool when machining each helical face. If too narrow, the cutter cannot complete the tooth form near the groove. If too wide, it reduces the effective face width of each helical section below the design value, lowering load-carrying capacity and contact ratio. Korea Ever-Power&#8217;s dimensional inspection report includes groove width and depth verification for every double helical gear.<\/p>\n<\/div>\n<hr style=\"border:none; border-top:1px dashed #cbd5e1; margin:16px 0;\">\n<div style=\"margin-bottom:20px;\">\n<p style=\"color:#1a3c6e; font-weight:700; margin-bottom:6px; font-size:clamp(15px, 2vw + 10px, 17px);\">Can you produce a double helical gear from a worn sample without a drawing?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px, 2vw + 10px, 16px);\">Yes. Send us the gear with outer diameter, tooth count, face width, bore, hub diameter, and hub length. Our engineering team measures the helix angle directly from the sample \u2014 a one-degree error in helix angle causes offset tooth contact and reduces thrust cancellation. A production drawing is prepared and submitted for customer approval before cutting begins.<\/p>\n<\/div>\n<hr style=\"border:none; border-top:1px dashed #cbd5e1; margin:16px 0;\">\n<div style=\"margin-bottom:20px;\">\n<p style=\"color:#1a3c6e; font-weight:700; margin-bottom:6px; font-size:clamp(15px, 2vw + 10px, 17px);\">How does lubrication work for high-power double helical gears?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px, 2vw + 10px, 16px);\">High-power double helical gears use splash or pressure-fed oil lubrication. The central groove creates a potential drainage path \u2014 oil flung by centrifugal force tends to drain from the central section. Lubrication systems must deliver oil to the mesh zone on both tooth faces, typically via spray nozzles aimed at both incoming and outgoing mesh zones, positioned to compensate for centrifugal drainage.<\/p>\n<\/div>\n<hr style=\"border:none; border-top:1px dashed #cbd5e1; margin:16px 0;\">\n<div style=\"margin-bottom:4px;\">\n<p style=\"color:#1a3c6e; font-weight:700; margin-bottom:6px; font-size:clamp(15px, 2vw + 10px, 17px);\">What information is needed to get a quotation?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px, 2vw + 10px, 16px);\">For a new design: module, tooth count, helix angle and hand on each face, pressure angle, face width, central groove width, bore type, material, heat treatment, accuracy class, and documentation requirements. For replacement from a worn sample: the measurements above, plus whether the original drawing is available. <a href=\"https:\/\/gearrack.top\/fr\/contact\/\" style=\"color:#1a3c6e; text-decoration:underline;\">Contact our engineering team<\/a> and we will return a feasibility review and price within two working days.<\/p>\n<\/div>\n<\/div>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Customer Reviews<\/h2>\n<div style=\"display:flex; flex-wrap:wrap; gap:14px; margin-top:20px;\">\n<div style=\"flex:1 1 100%; box-sizing:border-box; padding:20px 22px; background:#f0f6ff; border-radius:8px; border-left:4px solid #1a3c6e;\">\n<p style=\"font-style:italic; color:#374151; line-height:1.75; font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 10px;\">&#8220;We replaced double helical gear sets in a 12 MW steam turbine reduction gearbox \u2014 the original OEM had ceased support for this gear size. Korea Ever-Power reverse-engineered from our worn sample and produced to DIN 6 accuracy in 20CrNiMo carburised. The UT report, heat treatment curve, and dimensional inspection package met our power station operator&#8217;s maintenance documentation requirements. Gearbox has run 18 months since overhaul without issue.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px, 1.8vw + 8px, 15px);\"><strong style=\"color:#1a3c6e;\">Kim Hyeong-jun<\/strong> &nbsp;|&nbsp; Chief Mechanical Engineer, Gyeongnam Power Generation Co. &nbsp;&#183;&nbsp; <em style=\"color:#6b7280;\">Q1 2026<\/em><\/p>\n<\/div>\n<div style=\"flex:1 1 100%; box-sizing:border-box; padding:20px 22px; background:#ffffff; border-radius:8px; border:1px solid #d1dae8;\">\n<p style=\"font-style:italic; color:#374151; line-height:1.75; font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 10px;\">&#8220;We switched from single helical to <a href=\"https:\/\/gearrack.top\/fr\/product-category\/helical-gear\/\" style=\"color:#1a3c6e; text-decoration:underline;\">double helical gears<\/a> in our latest marine propulsion reduction gearbox generation. Eliminating the thrust bearing stage reduced gearbox length by 220 mm and weight by 380 kg at the same rated power. DNV material certificates and dimensional reports accepted without query on every delivery.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px, 1.8vw + 8px, 15px);\"><strong style=\"color:#1a3c6e;\">Park Seung-min<\/strong> &nbsp;|&nbsp; Gearbox Design Manager, Busan Marine Propulsion Systems &nbsp;&#183;&nbsp; <em style=\"color:#6b7280;\">Q3 2025<\/em><\/p>\n<\/div>\n<div style=\"flex:1 1 100%; box-sizing:border-box; padding:20px 22px; background:#f0f6ff; border-radius:8px; border-left:4px solid #1a3c6e;\">\n<p style=\"font-style:italic; color:#374151; line-height:1.75; font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 10px;\">&#8220;We needed replacement double helical gear sets in 42CrMo through-hardened for a hot strip rolling mill main reduction drive. Shock loading during strip entry was fracturing carburised replacement gears from our previous supplier. Ever-Power&#8217;s team correctly identified through-hardening as the appropriate route. No tooth fractures in 14 months of operation across two rolling lines.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px, 1.8vw + 8px, 15px);\"><strong style=\"color:#1a3c6e;\">Lee Jae-won<\/strong> &nbsp;|&nbsp; Plant Maintenance Manager, Incheon Steel Processing &nbsp;&#183;&nbsp; <em style=\"color:#6b7280;\">Q4 2025<\/em><\/p>\n<\/div>\n<div style=\"flex:1 1 100%; box-sizing:border-box; padding:20px 22px; background:#ffffff; border-radius:8px; border:1px solid #d1dae8;\">\n<p style=\"font-style:italic; color:#374151; line-height:1.75; font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 10px;\">&#8220;We supply integrally geared compressors for natural gas pipeline service. The double helical bull gear and pinion sets from Ever-Power in 20CrNiMo carburised to our DIN 5 drawing have passed incoming CMM inspection on all three batches received. Central groove width consistent to within 0.05 mm batch to batch.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px, 1.8vw + 8px, 15px);\"><strong style=\"color:#1a3c6e;\">Choi Byeong-soo<\/strong> &nbsp;|&nbsp; Component Procurement Lead, Daejeon Compressor Technology &nbsp;&#183;&nbsp; <em style=\"color:#6b7280;\">Q2 2025<\/em><\/p>\n<\/div>\n<div style=\"flex:1 1 100%; box-sizing:border-box; padding:20px 22px; background:#f0f6ff; border-radius:8px; border-left:4px solid #1a3c6e;\">\n<p style=\"font-style:italic; color:#374151; line-height:1.75; font-size:clamp(14px, 2vw + 10px, 16px); margin:0 0 10px;\">&#8220;We needed nitrided double helical gears for an offshore platform reduction gearbox \u2014 salt-air environment was causing corrosion pitting on through-hardened tooth flanks. Ever-Power specified 31CrMoV9 nitriding steel to our case depth requirement. Post-nitriding dimensions were within drawing tolerance without grinding. Corrosion pitting eliminated in two years since installation.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px, 1.8vw + 8px, 15px);\"><strong style=\"color:#1a3c6e;\">Ryu Chang-hyun<\/strong> &nbsp;|&nbsp; Reliability Engineer, Ulsan Offshore Plant Services &nbsp;&#183;&nbsp; <em style=\"color:#6b7280;\">Q1 2026<\/em><\/p>\n<\/div>\n<\/div>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px, 3vw + 10px, 30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:50px;\">Related Products<\/h2>\n<div style=\"display:flex; flex-wrap:wrap; gap:24px; margin-top:24px; align-items:stretch;\">\n<p>  <!-- Helical Gear \u5206\u7c7b\u5361 \u2014 600\u00d7600\u4ea7\u54c1\u56fe --><\/p>\n<div style=\"flex:1 1 280px; box-sizing:border-box; background:#f0f6ff; border-radius:10px; overflow:hidden; box-shadow:0 2px 10px rgba(26,60,110,0.10); display:flex; flex-direction:column;\">\n    <a href=\"https:\/\/gearrack.top\/fr\/product-category\/helical-gear\/\" style=\"display:block; line-height:0;\"><br \/>\n      <img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1449\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Industrial-Double-Helical-Gears.webp\" alt=\"Industrial Double Helical Gears\" width=\"600\" height=\"600\" style=\"width:100%; height:260px; object-fit:cover; display:block;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Industrial-Double-Helical-Gears.webp 600w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Industrial-Double-Helical-Gears-480x480.webp 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) 600px, 100vw\" \/><br \/>\n    <\/a><\/p>\n<div style=\"padding:20px 22px; flex:1; display:flex; flex-direction:column;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(16px, 2.2vw + 4px, 20px); margin:0 0 10px;\">Helical Gears<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0 0 16px; flex:1;\">From double helical and ground precision helical gears to crossed helical (screw) gears and internal helical ring gears \u2014 Korea Ever-Power&#8217;s full helical gear range covers every parallel and crossed-axis transmission requirement across all materials and accuracy grades.<\/p>\n<p>      <a href=\"https:\/\/gearrack.top\/fr\/product-category\/helical-gear\/\" style=\"display:inline-block; background:#1a3c6e; color:#ffffff; font-weight:700; font-size:clamp(13px, 1.8vw + 8px, 15px); padding:10px 20px; border-radius:5px; text-decoration:none; text-align:center;\">Browse Helical Gears \u2192<\/a>\n    <\/div>\n<\/p><\/div>\n<p>  <!-- Bevel Gear \u5206\u7c7b\u5361 \u2014 600\u00d7600\u4ea7\u54c1\u56fe --><\/p>\n<div style=\"flex:1 1 280px; box-sizing:border-box; background:#fff7ed; border-radius:10px; overflow:hidden; box-shadow:0 2px 10px rgba(232,160,32,0.12); display:flex; flex-direction:column;\">\n    <a href=\"https:\/\/gearrack.top\/fr\/product-category\/bevel-gears\/\" style=\"display:block; line-height:0;\"><br \/>\n      <img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1371\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Industrial-Bevel-Gears.webp\" alt=\"Engrenages coniques industriels\" width=\"600\" height=\"600\" style=\"width:100%; height:260px; object-fit:cover; display:block;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Industrial-Bevel-Gears.webp 600w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Industrial-Bevel-Gears-480x480.webp 480w\" sizes=\"(min-width: 0px) and (max-width: 480px) 480px, (min-width: 481px) 600px, 100vw\" \/><br \/>\n    <\/a><\/p>\n<div style=\"padding:20px 22px; flex:1; display:flex; flex-direction:column;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(16px, 2.2vw + 4px, 20px); margin:0 0 10px;\">Engrenages coniques<\/h3>\n<p style=\"font-size:clamp(13px, 1.8vw + 8px, 15px); color:#374151; line-height:1.7; margin:0 0 16px; flex:1;\">Where power must change direction between intersecting shafts, bevel gears are the standard solution. Korea Ever-Power&#8217;s bevel gear range covers straight, spiral, and zero-degree (Zerol) forms from miniature M0.15 instrument drives to M20 heavy industrial stages \u2014 in steel, stainless, brass, aluminium, and engineering plastics.<\/p>\n<p>      <a href=\"https:\/\/gearrack.top\/fr\/product-category\/bevel-gears\/\" style=\"display:inline-block; background:#e8a020; color:#ffffff; font-weight:700; font-size:clamp(13px, 1.8vw + 8px, 15px); padding:10px 20px; border-radius:5px; text-decoration:none; text-align:center;\">Browse Bevel Gears \u2192<\/a>\n    <\/div>\n<\/p><\/div>\n<\/div>\n<div style=\"background:#1a3c6e; color:#ffffff; padding:28px 32px; border-radius:8px; margin-top:40px; text-align:center;\">\n<h3 style=\"color:#ffffff; margin-top:0; font-size:clamp(18px, 2.4vw + 8px, 22px);\">Request a Quotation for Double Helical Gears<\/h3>\n<p style=\"color:#dbeafe; line-height:1.75; margin:10px 0 16px; font-size:clamp(14px, 2vw + 10px, 16px);\">Send us your drawing, worn sample, or application data \u2014 module, tooth count, helix angle, material, accuracy grade, and documentation requirements. For reverse engineering, include outer diameter, tooth count, face width, bore, and hub dimensions. Our engineering team returns a feasibility review and price within two working days.<\/p>\n<p><a href=\"https:\/\/gearrack.top\/fr\/contact\/\" style=\"display:inline-block; background:#e8a020; color:#ffffff; font-weight:700; font-size:clamp(14px, 2vw + 10px, 16px); padding:12px 28px; border-radius:5px; text-decoration:none; letter-spacing:0.3px;\">Get a Quote Now<\/a>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Double helical gears are a variation of helical gears in which two helical faces are placed next to each other with a gap separating them. Each face has identical but opposite helix angles. Employing a double-helical set of gears eliminates thrust loads and offers the possibility of even more significant tooth overlap and smoother operation.<\/p>","protected":false},"featured_media":1490,"comment_status":"closed","ping_status":"open","template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":""},"product_brand":[],"product_cat":[4558],"product_tag":[],"class_list":["post-1489","product","type-product","status-publish","has-post-thumbnail","product_cat-helical-gear","pa_editor-cxm","first","instock","product-type-simple"],"_links":{"self":[{"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/product\/1489","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/comments?post=1489"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/media\/1490"}],"wp:attachment":[{"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/media?parent=1489"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/product_brand?post=1489"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/product_cat?post=1489"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/gearrack.top\/fr\/wp-json\/wp\/v2\/product_tag?post=1489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}