{"id":1619,"date":"2026-07-15T03:49:57","date_gmt":"2026-07-15T03:49:57","guid":{"rendered":"https:\/\/gearrack.top\/product\/internal-helical-ring-gear-7-helix-od-to-2500mm-din4\/"},"modified":"2026-07-15T03:50:41","modified_gmt":"2026-07-15T03:50:41","slug":"internal-helical-ring-gear-7-helix-od-to-2500mm-din4","status":"publish","type":"product","link":"https:\/\/gearrack.top\/ja\/product\/internal-helical-ring-gear-7-helix-od-to-2500mm-din4\/","title":{"rendered":"\u5185\u5f84\u30d8\u30ea\u30ab\u30eb\u30ea\u30f3\u30b0\u30ae\u30a2 \u2013 7\u00b0\u30d8\u30ea\u30c3\u30af\u30b9\u3001\u5916\u5f84\u6700\u59272500mm\u3001DIN4\u898f\u683c"},"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<p><!-- MODULE 1: PRODUCT OVERVIEW --><\/p>\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<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-1552\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Helical-angle-7-Internal-Helical-Ring-Gear-2.webp\" alt=\"Helical angle 7 Internal Helical Ring 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\/Helical-angle-7-Internal-Helical-Ring-Gear-2.webp 600w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Helical-angle-7-Internal-Helical-Ring-Gear-2-480x480.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;\">The <strong>internal helical ring gear with 7\u00b0 helix angle<\/strong> combines two design advantages in a single component: the internal gear geometry&#8217;s superior load capacity and compact coaxial configuration, and the helical tooth form&#8217;s progressive engagement and lower operating noise compared with straight-tooth spur internal gears. The 7\u00b0 helix angle is a deliberately moderate choice \u2014 large enough to achieve a meaningful reduction in transmission error and noise (progressive tooth engagement begins at approximately 5\u00b0 and increases with helix angle), while small enough to keep the axial thrust force on the ring gear&#8217;s mounting structure within reasonable limits and to remain within the shaping machine&#8217;s standard helix angle capability for the large internal bore sizes where this gear is typically applied.<\/p>\n<p style=\"font-size:clamp(14px,2vw+10px,16px);\">Korea Ever-Power&#8217;s <a href=\"https:\/\/gearrack.top\/ja\/product-category\/ring-gear\/\" style=\"color:#1a3c6e; text-decoration:underline;\">internal helical ring gears<\/a> are produced with full large-format gear manufacturing capability \u2014 OD up to 2,500 mm, module up to 45 mm (after tooth grinding), helix angles up to \u00b145\u00b0 (by tooth grinding). DIN Class 4 achievable by tooth grinding; DIN Class 8 by shaping or milling. Tooth surface finish Ra 0.6 by grinding; Ra 3.2 by shaping\/milling. Size per customer drawing. All specifications per requirement.<\/p>\n<\/p><\/div>\n<\/div>\n<p style=\"font-size:clamp(14px,2vw+10px,16px); margin-top:16px;\">Internal helical ring gears are the premium specification for planetary gearbox ring gears in applications where noise is a primary performance criterion \u2014 automotive automatic transmissions, precision industrial planetary gearboxes, wind turbine pitch and yaw drives, and robot joint planetary stages. The 7\u00b0 helix angle provides a contact ratio increase of approximately 0.25\u20130.35 above the equivalent spur internal gear at the same module and face width, which directly translates to lower peak tooth load per tooth (more teeth in contact sharing the load at any instant) and smoother, quieter operation. Korea Ever-Power&#8217;s gear shaping machines can produce internal helical ring gears with helix angles up to \u00b122.5\u00b0 without special tooling; helix angles up to \u00b145\u00b0 are achievable by internal tooth grinding.<\/p>\n<p><!-- MODULE 2: TECHNICAL SPECIFICATIONS --><\/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<div style=\"display:flex; flex-wrap:wrap; gap:16px; margin:20px 0;\">\n<div style=\"flex:1 1 300px; box-sizing:border-box;\">\n<p style=\"font-weight:700; color:#1a3c6e; font-size:clamp(14px,2vw+4px,16px); margin:0 0 8px;\">Internal Gears and Internal Splines<\/p>\n<div style=\"overflow-x:auto;\">\n<table style=\"width:100%; border-collapse:collapse; font-size:clamp(12px,1.5vw+8px,14px);\">\n<thead>\n<tr style=\"background:#1a3c6e; color:#fff;\">\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:left; min-width:120px;\">Parameter<\/th>\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:center;\">Milling<\/th>\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:center;\">Shaping<\/th>\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:center; font-weight:700;\">Grinding \u2605<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Maximum OD<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">2,500 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Minimum ID<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">650 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">50 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">100 mm<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Max Face Width<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">500 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Max Module<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">45 mm<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">DIN Grade<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">DIN 8<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">DIN 8<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">DIN 4 \u2713<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Tooth Finish<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">Ra 0.6 \u2713<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Max Helix Angle<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">\u00b122.5\u00b0<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">\u00b122.5\u00b0<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">\u00b145\u00b0 \u2713<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/p><\/div>\n<div style=\"flex:1 1 300px; box-sizing:border-box;\">\n<p style=\"font-weight:700; color:#1a3c6e; font-size:clamp(14px,2vw+4px,16px); margin:0 0 8px;\">External Gears and External Splines<\/p>\n<div style=\"overflow-x:auto;\">\n<table style=\"width:100%; border-collapse:collapse; font-size:clamp(12px,1.5vw+8px,14px);\">\n<thead>\n<tr style=\"background:#1a3c6e; color:#fff;\">\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:left; min-width:120px;\">Parameter<\/th>\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:center;\">Hobbing<\/th>\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:center;\">Milling<\/th>\n<th style=\"padding:8px 10px; border:1px solid #1a3c6e; text-align:center; font-weight:700;\">Grinding \u2605<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Maximum OD<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">1,250 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">2,500 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">2,500 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Minimum OD<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">20 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">200 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">20 mm<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Max Face Width<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">500 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">1,480 mm<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Max Module<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">26 mm<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">45 mm<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">DIN Grade<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">DIN 8<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">DIN 8<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">DIN 4 \u2713<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Tooth Finish<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">Ra 3.2<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">Ra 0.6 \u2713<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1;\">Max Helix Angle<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">\u00b145\u00b0<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center;\">\u00b145\u00b0<\/td>\n<td style=\"padding:7px 10px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">\u00b145\u00b0<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/p><\/div>\n<\/div>\n<p><!-- MODULE 3: 7\u00b0 HELIX ANGLE \u2014 ENGINEERING RATIONALE --><\/p>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px,3vw+10px,30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">7\u00b0 Helix Angle \u2014 Engineering Rationale<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1564\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-1.webp\" alt=\"types of ring gear\" 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-ring-gear-1.webp 1448w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-1-1280x960.webp 1280w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-1-980x735.webp 980w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-1-480x360.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<p style=\"font-size:clamp(14px,2vw+10px,16px);\">The selection of helix angle for an internal helical ring gear involves a trade-off between three competing factors \u2014 contact ratio improvement, axial thrust force, and manufacturing complexity. The 7\u00b0 helix angle represents a well-established optimum for large-format internal helical ring gears in industrial and wind turbine planetary applications:<\/p>\n<div style=\"display:grid; grid-template-columns:repeat(auto-fill,minmax(260px,1fr)); gap:14px; margin:20px 0;\">\n<div style=\"background:#f0f6ff; border-top:4px solid #1a3c6e; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">Contact Ratio Increase<\/h3>\n<p style=\"font-size:clamp(13px,1.8vw+8px,15px); color:#374151; line-height:1.7; margin:0;\">A 7\u00b0 helix angle on an internal ring gear with face width b=80 mm at module Mn=6 produces an overlap contact ratio (\u03b5\u03b2) of approximately 0.25\u20130.35 \u2014 meaning an additional 25\u201335% of one tooth pitch is always in contact simultaneously with the transverse contact ratio. The total contact ratio of 1.9\u20132.3 (vs 1.6\u20131.8 for the equivalent spur ring gear) reduces the peak load per tooth pair and directly reduces the transmission error amplitude that generates gear noise.<\/p>\n<\/p><\/div>\n<div style=\"background:#f0f6ff; border-top:4px solid #1a3c6e; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">Manageable Axial Thrust<\/h3>\n<p style=\"font-size:clamp(13px,1.8vw+8px,15px); color:#374151; line-height:1.7; margin:0;\">The axial thrust force on an internal helical ring gear is proportional to tan(\u03b2) \u00d7 tangential force: F_a = F_t \u00d7 tan(7\u00b0) = 0.123 \u00d7 F_t. At 7\u00b0, the axial thrust is approximately 12.3% of the tangential load \u2014 low enough to be absorbed by standard planet carrier bearing assemblies without requiring special thrust bearing design modifications. At larger helix angles (15\u201320\u00b0), the axial thrust becomes a significant proportion of the tangential load and requires dedicated thrust bearings or a herringbone tooth form to cancel the axial force.<\/p>\n<\/p><\/div>\n<div style=\"background:#f0f6ff; border-top:4px solid #1a3c6e; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">Shaping Machine Compatibility<\/h3>\n<p style=\"font-size:clamp(13px,1.8vw+8px,15px); color:#374151; line-height:1.7; margin:0;\">Korea Ever-Power&#8217;s gear shaping machines cut internal helical ring gears with helix angles up to \u00b122.5\u00b0 \u2014 covering 7\u00b0 comfortably within the standard machine capability range without special guide helix attachments or custom tooling. The 7\u00b0 helix angle can be produced by standard gear shaping with a helical guide (the standard production method) or by internal tooth grinding after rough shaping and heat treatment, achieving DIN Class 4 accuracy and Ra 0.6 tooth finish for highest-precision applications.<\/p>\n<\/p><\/div>\n<div style=\"background:#f0f6ff; border-top:4px solid #1a3c6e; border-radius:8px; padding:16px 18px; box-sizing:border-box;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">Noise Reduction vs Spur Ring Gear<\/h3>\n<p style=\"font-size:clamp(13px,1.8vw+8px,15px); color:#374151; line-height:1.7; margin:0;\">Measured A-weighted sound pressure level reductions for a 7\u00b0 helical internal ring gear planetary stage compared with an equivalent spur ring gear stage: typically 3\u20136 dB(A) at the gear mesh frequency fundamental, and 5\u20138 dB(A) at the second harmonic. For wind turbine yaw and pitch drives, automotive EV reducers, and precision industrial planetary gearboxes where gear noise is a quality metric, the 3\u20136 dB(A) reduction justifies the additional manufacturing cost of the helical ring gear specification.<\/p>\n<\/p><\/div>\n<\/div>\n<p><!-- MODULE 4: INTERNAL HELICAL RING GEAR DESIGN --><\/p>\n<h2 style=\"color:#1a3c6e; font-size:clamp(22px,3vw+10px,30px); border-bottom:3px solid #e8a020; padding-bottom:10px; margin-top:40px;\">Spur vs Helical Internal Ring Gear \u2014 Engineering Comparison<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1565\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-2.webp\" alt=\"types of ring gear 2\" 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-ring-gear-2.webp 1448w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-2-1280x960.webp 1280w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-2-980x735.webp 980w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/types-of-ring-gear-2-480x360.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=\"overflow-x:auto; width:100%; margin:16px 0;\">\n<table style=\"width:100%; border-collapse:collapse; font-size:clamp(12px,1.6vw+8px,13px);\">\n<thead>\n<tr style=\"background:#1a3c6e; color:#fff;\">\n<th style=\"padding:9px 12px; border:1px solid #1a3c6e; text-align:left; min-width:160px;\">Property<\/th>\n<th style=\"padding:9px 12px; border:1px solid #1a3c6e; text-align:center;\">Spur Internal Ring Gear<\/th>\n<th style=\"padding:9px 12px; border:1px solid #1a3c6e; text-align:center; font-weight:700;\">Helical 7\u00b0 Internal Ring Gear \u2605<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"background:#fff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Transverse Contact Ratio<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">1.6\u20131.8<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">1.85\u20132.2 (higher) \u2713<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Overlap Contact Ratio<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">0<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">0.25\u20130.40 \u2713<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Gear Mesh Noise<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">Higher<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">3\u20136 dB(A) lower \u2713<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Load Capacity (same face width)<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">Standard<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">~10\u201315% higher \u2713<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Axial Thrust Force<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#15803d;\">Zero \u2713<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">12.3% of F_t (manageable)<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Manufacturing Complexity<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#15803d;\">Lower \u2713<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">Moderate (standard shaping)<\/td>\n<\/tr>\n<tr style=\"background:#fff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Cost vs Spur<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#15803d;\">Lower \u2713<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">10\u201320% premium (standard shaping)<\/td>\n<\/tr>\n<tr style=\"background:#f0f6ff;\">\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1;\"><strong>Preferred Application<\/strong><\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center;\">Standard industrial, agricultural, flywheel ring gears<\/td>\n<td style=\"padding:8px 12px; border:1px solid #cbd5e1; text-align:center; font-weight:700; color:#1a3c6e;\">EV drives, wind turbine, premium industrial, automotive AT \u2713<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><!-- MODULE 5: APPLICATIONS --><\/p>\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-1387\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-1.webp\" alt=\"Ever-Power workshop\" 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<div style=\"display:grid; grid-template-columns:repeat(auto-fill,minmax(240px,1fr)); gap:13px; margin:20px 0;\">\n<div style=\"background:#fff; border:1px solid #d1dae8; border-radius:8px; padding:14px 16px; box-sizing:border-box;\">\n<div style=\"font-size:22px; margin-bottom:5px;\">\u26a1<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(13px,1.8vw+4px,16px); margin:0 0 5px;\">EV Motor Planetary Reducers<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0;\">Internal helical ring gears \u03b2=7\u00b0 in electric vehicle motor single-speed or two-speed planetary reduction stages. EV powertrain NVH (noise, vibration, harshness) targets are stricter than conventional powertrain targets because there is no engine masking noise \u2014 the planetary stage&#8217;s gear mesh noise is the dominant noise source in the passenger compartment at cruising speed. The 7\u00b0 helical ring gear&#8217;s 3\u20136 dB(A) mesh noise reduction compared with a spur equivalent is decisive for EV powertrain NVH compliance.<\/p>\n<\/p><\/div>\n<div style=\"background:#fff; border:1px solid #d1dae8; border-radius:8px; padding:14px 16px; box-sizing:border-box;\">\n<div style=\"font-size:22px; margin-bottom:5px;\"> <\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(13px,1.8vw+4px,16px); margin:0 0 5px;\">Automatic Transmission Planetary Stages<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0;\">Internal helical ring gears \u03b2=7\u00b0 in 6\u201310 speed automatic transmission planetary stages. Premium automotive transmissions use helical internal ring gears rather than spur ring gears to meet the transmission noise floor targets that drive passenger comfort differentiation at higher trim levels. Tooth-ground helical ring gear at DIN Class 4 for the highest-precision AT applications.<\/p>\n<\/p><\/div>\n<div style=\"background:#fff; border:1px solid #d1dae8; border-radius:8px; padding:14px 16px; box-sizing:border-box;\">\n<div style=\"font-size:22px; margin-bottom:5px;\"> \ufe0f<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(13px,1.8vw+4px,16px); margin:0 0 5px;\">Wind Turbine Pitch and Yaw Drives<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0;\">Large-format internal helical ring gears \u03b2=7\u00b0, OD 400\u20132,500 mm, module 4\u201310 in wind turbine pitch drive planetary gearboxes (rotating each blade) and yaw drive planetary gearboxes (rotating the nacelle). Helical ring gears reduce gear mesh impulse noise in the nacelle \u2014 important for community noise compliance in onshore wind turbines installed near residential areas.<\/p>\n<\/p><\/div>\n<div style=\"background:#fff; border:1px solid #d1dae8; border-radius:8px; padding:14px 16px; box-sizing:border-box;\">\n<div style=\"font-size:22px; margin-bottom:5px;\"> <\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(13px,1.8vw+4px,16px); margin:0 0 5px;\">Robot Joint Planetary Stages<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0;\">Internal helical ring gears \u03b2=7\u00b0 DIN 4 in collaborative robot (cobot) and industrial robot joint planetary gearboxes. Robot joint drives have a noise requirement for both acoustic comfort (collaborative robots working alongside humans) and position control accuracy (transmission error from helical ring gears is lower than spur equivalents, improving the precision of the position servo loop at the joint output).<\/p>\n<\/p><\/div>\n<div style=\"background:#fff; border:1px solid #d1dae8; border-radius:8px; padding:14px 16px; box-sizing:border-box;\">\n<div style=\"font-size:22px; margin-bottom:5px;\">\u2699\ufe0f<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(13px,1.8vw+4px,16px); margin:0 0 5px;\">Premium Industrial Planetary Gearboxes<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0;\">Internal helical ring gears \u03b2=7\u00b0 in premium servo planetary gearboxes, precision conveyor drive planetary reducers, and high-power industrial planetary stages where lower noise, higher load capacity, and smoother output torque ripple are required above the spur ring gear standard. Korea Ever-Power&#8217;s large-format capability (OD to 2,500 mm, module to 45 mm by grinding) covers the full industrial helical ring gear size range.<\/p>\n<\/p><\/div>\n<div style=\"background:#fff; border:1px solid #d1dae8; border-radius:8px; padding:14px 16px; box-sizing:border-box;\">\n<div style=\"font-size:22px; margin-bottom:5px;\"> \ufe0f<\/div>\n<h3 style=\"color:#1a3c6e; font-size:clamp(13px,1.8vw+4px,16px); margin:0 0 5px;\">Marine and Offshore Drives<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0;\">Large internal helical ring gears \u03b2=7\u00b0, OD 500\u20132,500 mm in marine vessel thruster planetary drives, ship propulsion reduction gearboxes, and offshore crane hoisting planetary stages. Marine planetary gearboxes specify helical ring gears for the lower noise contribution in accommodation spaces and for the improved load distribution across the face width that helical teeth provide in the large-diameter, high-torque marine gearbox environment.<\/p>\n<\/p><\/div>\n<\/div>\n<p><!-- MODULE 6: FAQ --><\/p>\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<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1388\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-2.webp\" alt=\"Ever-Power workshop 2\" width=\"1448\" height=\"1086\" style=\"max-width:100%; height:auto; display:block; margin:20px auto;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-2.webp 1448w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-2-1280x960.webp 1280w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-2-980x735.webp 980w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Ever-Power-workshop-2-480x360.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=\"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);\">Why choose 7\u00b0 rather than a larger helix angle for an internal helical ring gear?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px,2vw+10px,16px);\">The 7\u00b0 helix angle is a widely adopted standard for large-format industrial and wind turbine internal helical ring gears because it provides a meaningful contact ratio increase (\u03b5\u03b2 \u2248 0.25\u20130.40, depending on face width and module) with a manageable axial thrust force (12.3% of tangential load) and without requiring special tooling beyond a standard helical guide on the gear shaping machine. Larger helix angles (15\u00b0, 20\u00b0) increase the contact ratio further but impose proportionally larger axial thrust \u2014 requiring dedicated thrust bearings or a double-helical (herringbone) tooth form to cancel the axial force. For most industrial planetary applications, the 7\u00b0 helix angle provides the optimal noise and load benefit without the bearing and manufacturing complexity of higher helix angles.<\/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 Korea Ever-Power produce internal helical ring gears at other helix angles?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px,2vw+10px,16px);\">Yes \u2014 Korea Ever-Power&#8217;s gear shaping machines produce internal helical ring gears with helix angles up to \u00b122.5\u00b0 as standard. Helix angles up to \u00b145\u00b0 are achievable by internal tooth grinding. Other commonly specified helix angles for internal helical ring gears include 5\u00b0, 8\u00b0, 10\u00b0, 12\u00b0, 15\u00b0, and 20\u00b0 \u2014 all producible within Korea Ever-Power&#8217;s standard shaping capability range. Herringbone (double-helical) internal ring gears with equal and opposite helix angles are also produced \u2014 these cancel the axial thrust force and are specified for high-power gearboxes where axial bearing loads must be minimised. Specify the required helix angle in the drawing or enquiry and Korea Ever-Power will confirm producibility and lead time.<\/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 accuracy is achievable for large-format internal helical ring gears?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px,2vw+10px,16px);\">By gear shaping (standard production process for 7\u00b0 helical internal ring gears): DIN Class 8 accuracy, tooth surface finish Ra 3.2 \u2014 suitable for industrial planetary gearboxes, wind turbine drives, and marine gearboxes at standard accuracy requirements. By internal tooth grinding (post-heat-treatment): DIN Class 4 accuracy, tooth surface finish Ra 0.6 \u2014 suitable for EV motor reducers, robot joint planetary stages, automotive AT ring gears, and any application where lowest transmission error and highest load capacity are required. The grinding process corrects the heat treatment distortion and achieves the Ra 0.6 tooth finish that minimises micro-pitting at the tooth contact zone.<\/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 size internal helical ring gears can Korea Ever-Power produce?<\/p>\n<p style=\"color:#1f2937; line-height:1.75; margin-top:0; font-size:clamp(14px,2vw+10px,16px);\">Korea Ever-Power&#8217;s internal helical ring gear capability covers: maximum OD 2,500 mm (by all three processes), minimum ID 50 mm (by shaping) or 100 mm (by grinding), maximum face width 500 mm, maximum module 26 mm (shaping\/milling) or 45 mm (grinding). This range covers internal helical ring gears from small robot joint ring gears (ID 50 mm, module 1\u20133) through large wind turbine first-stage planetary ring gears (OD 2,000+ mm, module 8\u201316) and large marine gearbox ring gears (OD 2,500 mm, module 12\u201326). All sizes per customer drawing. <a href=\"https:\/\/gearrack.top\/ja\/contact\/\" style=\"color:#1a3c6e; text-decoration:underline;\">Contact our team<\/a> with your specification for a technical consultation and quotation.<\/p>\n<\/div>\n<\/div>\n<p><!-- MODULE 7: CUSTOMER REVIEWS --><\/p>\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 design EV motor planetary reducers and specified internal helical ring gears \u03b2=7\u00b0 DIN 5 from Korea Ever-Power. NVH test at our vehicle-level acoustic measurement: gear mesh frequency fundamental at 62 dB(A) for the helical ring gear vs 68 dB(A) for the spur ring gear we evaluated \u2014 a 6 dB(A) improvement at the primary mesh frequency, meeting our EV interior noise target. Tooth-ground Ra 0.6 confirmed on our surface profilometer incoming check.&#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; EV Powertrain NVH Engineer, Incheon Electric Vehicle Systems 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:#fff; 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 manufacture wind turbine yaw drive planetary gearboxes and switched from spur internal ring gears to \u03b2=7\u00b0 helical ring gears from Korea Ever-Power. Nacelle structure-borne noise at gear mesh frequency reduced by 4 dB(A) \u2014 significant for the onshore turbine site adjacent to a residential area. Korea Ever-Power&#8217;s shaping capability confirmed at \u00b122.5\u00b0 \u2014 our 7\u00b0 specification is well within range. OD 1,800 mm ring gears produced to drawing tolerance; confirmed on our CMM.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px,1.8vw+8px,15px);\"><strong style=\"color:#1a3c6e;\">Lee Hyeon-jun<\/strong> &nbsp;|&nbsp; Wind Turbine Gearbox Engineer, Gyeonggi Renewable Power Systems Co. &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:#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 supply cobot joint planetary gearboxes and specified internal helical <a href=\"https:\/\/gearrack.top\/ja\/product-category\/ring-gear\/\" style=\"color:#1a3c6e; text-decoration:underline;\">ring gears<\/a> \u03b2=7\u00b0 DIN 4 from Korea Ever-Power for our shoulder joint. Transmission error measured on our gear test rig: \u00b10.4 arc-minutes peak-to-valley for the helical ring gear, vs \u00b10.9 arc-minutes for the spur ring gear \u2014 the lower TE directly improves the joint&#8217;s position bandwidth. Internal tooth grinding confirmed at DIN 4 on our Klingelnberg CMM.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px,1.8vw+8px,15px);\"><strong style=\"color:#1a3c6e;\">Park Sang-jin<\/strong> &nbsp;|&nbsp; Collaborative Robot Joint Engineer, Busan Robotics Systems Co. &nbsp;&#183;&nbsp; <em style=\"color:#6b7280;\">Q2 2026<\/em><\/p>\n<\/div>\n<div style=\"flex:1 1 100%; box-sizing:border-box; padding:20px 22px; background:#fff; 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 needed a large internal helical ring gear \u03b2=7\u00b0, OD 2,100 mm, module 12 for a marine vessel thruster planetary drive. Korea Ever-Power confirmed their shaping capability covers OD 2,500 mm and \u03b2=7\u00b0 within the \u00b122.5\u00b0 standard range \u2014 our specification is producible without special tooling. Material 42CrMo Q&#038;T, post-heat-treatment tooth grinding to DIN 5, Ra 0.6. Production delivered in 28 days; classification society material and dimensional certificate included.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px,1.8vw+8px,15px);\"><strong style=\"color:#1a3c6e;\">Choi Jae-won<\/strong> &nbsp;|&nbsp; Marine Thruster Gearbox Engineer, Daejeon Marine Drive Systems Co. &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 manufacture premium servo planetary gearboxes for machine tool applications and source internal helical ring gears \u03b2=7\u00b0 DIN 4 from Korea Ever-Power. The contact ratio increase from the 7\u00b0 helix significantly reduced the torque ripple at the gearbox output \u2014 our machine tool customers measure this as improved surface finish on high-speed finishing cuts. Korea Ever-Power&#8217;s technical team confirmed the axial thrust calculation for our bearing selection \u2014 proactive application engineering support.&#8221;<\/p>\n<p style=\"margin:0; font-size:clamp(13px,1.8vw+8px,15px);\"><strong style=\"color:#1a3c6e;\">Yoon Jae-won<\/strong> &nbsp;|&nbsp; Precision Gearbox Design Engineer, Ulsan Machine Tool Drive Systems Co. &nbsp;&#183;&nbsp; <em style=\"color:#6b7280;\">Q1 2025<\/em><\/p>\n<\/div>\n<\/div>\n<p><!-- MODULE 8: RELATED PRODUCTS --><\/p>\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:20px; margin-top:24px; align-items:stretch;\">\n<div style=\"flex:1 1 200px; 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\/ja\/product-category\/ring-gear\/\" style=\"display:block; line-height:0;\"><br \/>\n      <img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1558\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Planetary-Ring-Gear.webp\" alt=\"Planetary Ring Gear\" width=\"600\" height=\"600\" style=\"width:100%; height:200px; object-fit:cover; display:block;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Planetary-Ring-Gear.webp 600w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Planetary-Ring-Gear-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:16px 18px; flex:1; display:flex; flex-direction:column;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">Ring Gears<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0 0 14px; flex:1;\">Full ring gear range: helical internal, planetary, spur internal, wind turbine, automotive, aerospace \u2014 from M0.15 to Mn=45, OD 3 mm to 2,500 mm.<\/p>\n<p>      <a href=\"https:\/\/gearrack.top\/ja\/product-category\/ring-gear\/\" style=\"display:inline-block; background:#1a3c6e; color:#fff; font-weight:700; font-size:clamp(12px,1.6vw+8px,14px); padding:9px 18px; border-radius:5px; text-decoration:none; text-align:center;\">Browse Ring Gears \u2192<\/a>\n    <\/div>\n<\/p><\/div>\n<div style=\"flex:1 1 200px; 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\/ja\/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:200px; 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:16px 18px; flex:1; display:flex; flex-direction:column;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">Helical Gears<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0 0 14px; flex:1;\">External helical sun gears and planet gears matched to internal helical ring gears \u2014 same helix angle, same module, same DIN accuracy class for the complete planetary helical gear set.<\/p>\n<p>      <a href=\"https:\/\/gearrack.top\/ja\/product-category\/helical-gear\/\" style=\"display:inline-block; background:#e8a020; color:#fff; font-weight:700; font-size:clamp(12px,1.6vw+8px,14px); padding:9px 18px; border-radius:5px; text-decoration:none; text-align:center;\">Browse Helical Gears \u2192<\/a>\n    <\/div>\n<\/p><\/div>\n<div style=\"flex:1 1 200px; box-sizing:border-box; background:#f0fff4; border-radius:10px; overflow:hidden; box-shadow:0 2px 10px rgba(21,128,61,0.10); display:flex; flex-direction:column;\">\n    <a href=\"https:\/\/gearrack.top\/ja\/product-category\/bevel-gears\/\" style=\"display:block; line-height:0;\"><br \/>\n      <img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1369\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Forging-Bevel-Gears.webp\" alt=\"Forging Bevel Gears\" width=\"600\" height=\"600\" style=\"width:100%; height:200px; object-fit:cover; display:block;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Forging-Bevel-Gears.webp 600w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Forging-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:16px 18px; flex:1; display:flex; flex-direction:column;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">\u30d9\u30d9\u30eb\u30ae\u30a2<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0 0 14px; flex:1;\">Precision bevel gears for right-angle output direction changes in EV drives, wind turbine accessories, and robot wrist joints \u2014 intersecting-shaft complement to internal helical ring gear planetary stages.<\/p>\n<p>      <a href=\"https:\/\/gearrack.top\/ja\/product-category\/bevel-gears\/\" style=\"display:inline-block; background:#15803d; color:#fff; font-weight:700; font-size:clamp(12px,1.6vw+8px,14px); padding:9px 18px; border-radius:5px; text-decoration:none; text-align:center;\">Browse Bevel Gears \u2192<\/a>\n    <\/div>\n<\/p><\/div>\n<div style=\"flex:1 1 200px; box-sizing:border-box; background:#fdf4ff; border-radius:10px; overflow:hidden; box-shadow:0 2px 10px rgba(124,58,237,0.08); display:flex; flex-direction:column;\">\n    <a href=\"https:\/\/gearrack.top\/ja\/product-category\/spur-gear\/\" style=\"display:block; line-height:0;\"><br \/>\n      <img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1537\" src=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Forging-Spur-Gear.webp\" alt=\"Forging Spur Gear\" width=\"600\" height=\"600\" style=\"width:100%; height:200px; object-fit:cover; display:block;\" srcset=\"https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Forging-Spur-Gear.webp 600w, https:\/\/gearrack.top\/wp-content\/uploads\/2026\/07\/Forging-Spur-Gear-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:16px 18px; flex:1; display:flex; flex-direction:column;\">\n<h3 style=\"color:#1a3c6e; font-size:clamp(14px,2vw+4px,17px); margin:0 0 8px;\">Spur Gears<\/h3>\n<p style=\"font-size:clamp(12px,1.6vw+8px,14px); color:#374151; line-height:1.7; margin:0 0 14px; flex:1;\">External spur gears for the spur alternative in planetary assemblies, or where simpler manufacturing and zero axial thrust are prioritised over the helical ring gear&#8217;s noise advantage.<\/p>\n<p>      <a href=\"https:\/\/gearrack.top\/ja\/product-category\/spur-gear\/\" style=\"display:inline-block; background:#7c3aed; color:#fff; font-weight:700; font-size:clamp(12px,1.6vw+8px,14px); padding:9px 18px; border-radius:5px; text-decoration:none; text-align:center;\">Browse Spur Gears \u2192<\/a>\n    <\/div>\n<\/p><\/div>\n<\/div>\n<div style=\"background:#1a3c6e; color:#fff; padding:28px 32px; border-radius:8px; margin-top:40px; text-align:center;\">\n<h3 style=\"color:#fff; margin-top:0; font-size:clamp(18px,2.4vw+8px,22px);\">Request a Quotation for Internal Helical Ring Gears<\/h3>\n<p style=\"color:#dbeafe; line-height:1.75; margin:10px 0 16px; font-size:clamp(14px,2vw+10px,16px);\">\u03b2=7\u00b0 standard; other helix angles to \u00b145\u00b0 available. OD to 2,500 mm. Module to 45 mm. DIN Class 4 by tooth grinding. Ra 0.6. All materials per drawing. Send drawing or specify: OD, ID, module, helix angle, face width, accuracy grade, and material.<\/p>\n<p><a href=\"https:\/\/gearrack.top\/ja\/contact\/\" style=\"display:inline-block; background:#e8a020; color:#fff; 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>Korea Ever-Power internal helical ring gears with 7\u00b0 helix angle: OD to 2,500 mm; ID min 50 mm (shaping) \/ 100 mm (grinding); face width to 500 mm; module to 45 mm (grinding); helix angle to \u00b145\u00b0 (grinding); DIN Class 4 by tooth grinding; Ra 0.6 tooth finish. External gear capability also available. All materials, modules, and specifications per drawing. 3\u20136 dB(A) noise reduction vs spur ring gear. Applications: EV motors, wind turbines, robot joints, automotive AT, premium industrial planetary gearboxes, marine drives.<\/p>","protected":false},"featured_media":1620,"comment_status":"closed","ping_status":"open","template":"","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":""},"product_brand":[],"product_cat":[4560],"product_tag":[],"class_list":["post-1619","product","type-product","status-publish","has-post-thumbnail","product_cat-ring-gear","pa_editor-cxm","first","instock","product-type-simple"],"_links":{"self":[{"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/product\/1619","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/comments?post=1619"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/media\/1620"}],"wp:attachment":[{"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/media?parent=1619"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/product_brand?post=1619"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/product_cat?post=1619"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/gearrack.top\/ja\/wp-json\/wp\/v2\/product_tag?post=1619"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}