{"id":2020,"date":"2026-04-10T06:51:53","date_gmt":"2026-04-10T06:51:53","guid":{"rendered":"https:\/\/helicalcutgears.top\/?post_type=product&p=2020"},"modified":"2026-04-10T06:51:53","modified_gmt":"2026-04-10T06:51:53","slug":"ground-helical-gears-precision-ground-15-and-1931-for-smooth-high-load-transmission","status":"publish","type":"product","link":"https:\/\/helicalcutgears.top\/da\/product\/ground-helical-gears-precision-ground-15-and-1931-for-smooth-high-load-transmission\/","title":{"rendered":"Slibede spiralformede gear \u2014 Pr\u00e6cisionsslebet 15\u00b0 og 19\u00b031\u2032 for j\u00e6vn transmission ved h\u00f8j belastning"},"content":{"rendered":"
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Ground Helical Gear \u2014 Overview<\/h2>\n

EN ground helical gear<\/strong> is a spiralformet gear<\/strong> whose tooth flanks have been finish-ground after hobbing or shaping, rather than left in the as-cut condition. Grinding removes the tool marks left by the hob or shaper cutter and corrects minor errors in tooth profile and lead introduced during the cutting operation. The result is a smoother tooth surface \u2014 typically Ra 0.4\u20130.8 \u00b5m compared to Ra 1.6\u20133.2 \u00b5m for a well-hobbed gear \u2014 which reduces sliding friction between mating teeth, lowers operating temperature, and extends fatigue life under cyclic loading.<\/p>\n

\"Jordskrueformet<\/p>\n

Korea Ever-Power Worm Gear Co.,Ltd produces ground helical gears<\/strong> in two standard helix angle variants: 15\u00b0 and 19\u00b031′. Both are available in left-hand and right-hand configurations. The 15\u00b0 series is designed as a direct substitute for straight spur gears in applications where the existing shaft geometry already suits the small amount of axial force a 15\u00b0 helix produces. The 19\u00b031′ series is matched to run with gear racks of the same helix angle, covering applications in linear motion systems, machine tool tables, and positioning drives where the rack-and-pinion combination must engage smoothly without lead error. Replacement configurations compatible with standard metric precision gear catalogs are available \u2014 provide your existing part number or drawing for a cross-reference.<\/p>\n

Tekniske specifikationer<\/h2>\n

The reference specification below applies to the Module 1, 100-tooth, left-hand ground helical gear series. Korea Ever-Power also supplies this design in right-hand configuration; a matched pair of opposite-hand gears will rotate two parallel shafts in opposite directions. Custom tooth counts, bore sizes, and hub dimensions are available on request.<\/p>\n

Module 1, 100 Tooth, Left Hand, Ground Helical Gear \u2014 Reference Data<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nV\u00e6rdi<\/th>\n<\/tr>\n
Bore Type<\/strong><\/td>\nJord<\/td>\n<\/tr>\n
Tv\u00e6rg\u00e5ende modul<\/strong><\/td>\n1<\/td>\n<\/tr>\n
No. of Teeth<\/strong><\/td>\n100<\/td>\n<\/tr>\n
Direction of Helix<\/strong><\/td>\nLeft Hand<\/td>\n<\/tr>\n
Form<\/strong><\/td>\nS1<\/td>\n<\/tr>\n
Bore (A)<\/strong><\/td>\n15.0 mm<\/td>\n<\/tr>\n
Hub Diameter (B)<\/strong><\/td>\n50.0 mm<\/td>\n<\/tr>\n
Pitch Diameter (C)<\/strong><\/td>\n100.00 mm<\/td>\n<\/tr>\n
Outer Diameter (D)<\/strong><\/td>\n102.00 mm<\/td>\n<\/tr>\n
Face Width (E)<\/strong><\/td>\n8.0 mm<\/td>\n<\/tr>\n
Hub Width (F)<\/strong><\/td>\n10.0 mm<\/td>\n<\/tr>\n
Total Length (G)<\/strong><\/td>\n18.00 mm<\/td>\n<\/tr>\n
Helixvinkel<\/strong><\/td>\n21\u00b030′<\/td>\n<\/tr>\n
Trykvinkel<\/strong><\/td>\n20\u00b0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Ground vs Hobbed Helical Gear \u2014 What the Difference Means in Practice<\/h2>\n

Both hobbed and ground spiralformede tandhjul<\/strong> start from the same blank and the same tooth form, but the manufacturing process diverges at the finishing stage. Hobbing removes material efficiently with a worm-type multi-tooth cutter and is the standard process for general-purpose gears. Grinding uses abrasive wheels to correct the residual errors in tooth profile and lead that hobbing leaves behind. The table below summarizes the practical differences between the two processes at the level of detail that matters for gear performance.<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nHobbed Helical Gear<\/th>\nGround Helical Gear<\/th>\n<\/tr>\n
Tooth surface finish (Ra)<\/td>\n1.6\u20133.2 \u00b5m<\/td>\n0.4\u20130.8 \u00b5m<\/td>\n<\/tr>\n
ISO 1328 accuracy class (typical)<\/td>\nISO 7\u20139<\/td>\nISO 4\u20136<\/td>\n<\/tr>\n
Allowable contact stress (same material)<\/td>\nModerat<\/td>\nHigher \u2014 surface integrity from grinding reduces pitting initiation sites<\/td>\n<\/tr>\n
Noise at high speed<\/td>\nAudible harmonic mesh tone increases with speed<\/td>\nLower mesh tone; profile accuracy reduces transmission error excitation<\/td>\n<\/tr>\n
Run-in period required<\/td>\nTypically 40\u2013100 hours at partial load<\/td>\nShorter or none \u2014 contact pattern is correct from first mesh<\/td>\n<\/tr>\n
Enhedspris<\/td>\nLower<\/td>\nHigher \u2014 additional process step adds cost and lead time<\/td>\n<\/tr>\n
Typiske anvendelser<\/td>\nGeneral industrial drives, low to moderate speed<\/td>\nMachine tools, servo drives, turbine gearboxes, precision instruments<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

\"straight<\/p>\n

15\u00b0 vs 19\u00b031′ Helix Angle \u2014 Choosing the Right Series<\/h2>\n

The two helix angle options offered in the Korea Ever-Power ground helical gear<\/strong> range are not interchangeable \u2014 each is optimized for a specific engagement geometry. Selecting the wrong angle series for a given application will result in a lead error at the mesh, elevated noise, and uneven load distribution across the face width.<\/p>\n

15\u00b0 Ground Helical Gear Series<\/h3>\n

The 15\u00b0 series is engineered as a spur gear substitute. A 15\u00b0 helix angle produces a small axial force component \u2014 roughly 27% of the tangential load \u2014 which is manageable with standard deep-groove bearings without thrust preloading. The gradual diagonal tooth contact gives a measurably smoother torque curve and lower noise floor compared with a spur gear of the same module and tooth count. A matched pair of left-hand and right-hand 15\u00b0 gears will rotate parallel output shafts in opposite directions, which suits applications where counter-rotation is needed. For instrument drives, light machine tool heads, and benchtop precision equipment, the 15\u00b0 ground series offers an easy upgrade path from spur gears without gearbox housing redesign.<\/p>\n

19\u00b031′ Ground Helical Gear Series<\/h3>\n

The 19\u00b031′ series is designed to mesh with gear racks manufactured to the same helix angle. This angle is a recognized standard in the precision gear rack industry \u2014 it was established so that the rack tooth form and the pinion tooth form, when both are ground to the same helix angle, produce a theoretically perfect involute contact. Machine tool table drives, gantry positioning systems, and robotic linear axes that use precision ground racks should use 19\u00b031′ ground pinions to achieve the smooth, low-backlash motion these applications demand. Mismatching the pinion angle with a standard 15\u00b0 series or an unhelical spur pinion on a 19\u00b031′ rack will introduce transmission error and shorten rack and pinion service life.<\/p>\n

Key Advantages of Grinding for Helical Gears<\/h2>\n
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\u2726 More Accurate Tooth Profile<\/strong><\/p>\n

Precision ground helical gears achieve a tighter tooth profile than machined or cut gears, providing smoother mesh and more controlled motion output \u2014 critical for servo-driven axes and instrument transmissions.<\/p>\n<\/div>\n

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\u2726 Broader Material Compatibility<\/strong><\/p>\n

Grinding works on hardened materials that cannot be hobbed after heat treatment. This means the gear can be carburized or through-hardened first, then ground to final dimensions \u2014 combining maximum core toughness with a hard, wear-resistant tooth surface.<\/p>\n<\/div>\n

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\u2726 Higher Load and Torque Capacity<\/strong><\/p>\n

Ground helical gears handle higher contact stresses than cut gears of equivalent size. The finer surface finish reduces asperity stress concentrations that nucleate pitting, allowing them to operate closer to the material’s fatigue strength limit in high-torque applications.<\/p>\n<\/div>\n

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\u2726 Reduced Run-In Time<\/strong><\/p>\n

Because the contact pattern is already optimized at the grinding stage, ground helical gears can often be run at full load immediately after installation. Hobbed gears typically require a break-in period of 40\u2013100 operating hours at reduced load to smooth high spots before full-load operation.<\/p>\n<\/div>\n<\/div>\n

\"typer<\/p>\n

Precision Grades and Inspection<\/h2>\n

Gear accuracy is specified by international standards including ISO 1328, AGMA 2000, DIN 3961, and JIS B 1702. These standards define tolerance bands for total profile error, lead error, pitch deviation, and runout. Korea Ever-Power ground helical gears<\/strong> are manufactured to ISO 1328 class 5\u20136 as standard, with ISO class 4 available on request for the highest-precision applications.<\/p>\n