{"id":590,"date":"2026-05-28T03:56:08","date_gmt":"2026-05-28T03:56:08","guid":{"rendered":"https:\/\/planetary-gearboxes.com\/?post_type=product&p=590"},"modified":"2026-05-29T06:04:37","modified_gmt":"2026-05-29T06:04:37","slug":"ep-af-high-rigidity-inline-planetary-gearbox","status":"publish","type":"product","link":"https:\/\/planetary-gearboxes.com\/hi\/product\/ep-af-high-rigidity-inline-planetary-gearbox\/","title":{"rendered":"EP-AF Series High-Rigidity Output Shaft Inline Planetary Gearbox (EP-AF042 to EP-AF220, and EP-AFX Variant)"},"content":{"rendered":"
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EP-AF Series \u2014 High-Rigidity Enlarged Output Shaft Inline Planetary Gearbox<\/h2>\n
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\"EP-AF<\/p>\n

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Hi Radial
\nLoad<\/div>\n
Enlarged output shaft<\/div>\n<\/div>\n
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\u22641′<\/div>\n
Backlash P0 (arcmin)<\/div>\n<\/div>\n
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\u226597%<\/div>\n
Single-Stage Efficiency<\/div>\n<\/div>\n
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\u221210~+90\u00b0C<\/div>\n
Operating Range<\/div>\n<\/div>\n<\/div>\n

\n\u2190 Browse All Planetary Gearbox Series
\n<\/a><\/div>\n<\/div>\n
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\u2605 Hi Radial Load \u2014 The Inline Series Designed for Direct Shaft-End Mounting<\/div>\n

EP-AF is the Korea Ever-Power inline precision planetary gearbox series catalogued specifically for high radial load<\/strong> applications. The enlarged diameter output shaft directly supports gear, pulley, sprocket, and cam mounting without a separate bearing housing \u2014 a configuration the standard-diameter EP-AB shaft is not rated for.<\/p>\n<\/div>\n

The EP-AF series high-rigidity inline planetary gearbox<\/strong> differs from the EP-AB square-flange series<\/a> in exactly one structural dimension: the output shaft diameter. EP-AF uses an enlarged diameter output shaft<\/strong> whose increased cross-section delivers substantially higher bending stiffness and radial load capacity \u2014 the property that defines an EP-AF application. When a belt pulley, timing gear, or eccentric cam is mounted directly on the output shaft end and its weight or belt tension creates a radial force on the shaft, the EP-AF’s enlarged shaft resists the resulting bending moment without deflection that would compromise tooth mesh accuracy, bearing life, or positioning repeatability.<\/p>\n

All other specifications \u2014 backlash grades P0\/P1\/P2, single-stage efficiency \u226597%, operating temperature \u221210 \u00b0C to +90 \u00b0C, IP65 protection, and the complete ratio set from i=3 to i=100 two-stage \u2014 are identical to EP-AB. The EP-AFX variant<\/strong> covers the same specification at a reduced maximum torque of 1,200 N\u00b7m in ten frame sizes, for applications where the full 2,000 N\u00b7m of EP-AF220 is not required.<\/p>\n

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\u26a1 Enlarged Shaft<\/div>\n
Direct gear\/pulley\/cam mounting \u2014 no separate bearing housing.<\/div>\n<\/div>\n
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\ud83d\udcd0 P0\/P1\/P2 Grades<\/div>\n
Same three precision levels as EP-AB \u2014 sub-arcminute P0 available.<\/div>\n<\/div>\n
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\ud83d\udce6 + EP-AFX<\/div>\n
Same spec, up to 1,200 N\u00b7m, AF042\u2013AF180 frame range.<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

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The High-Rigidity Output Shaft \u2014 Why Output Shaft Diameter Is the Critical Selection Variable<\/h2>\n
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STANDARD SHAFT \u2014 EP-AB<\/p>\n

Motor \u2500\u2500\u2500\u2500 Gearbox \u2500\u2500\u2500\u2500 Coupling
\n\u2502
\n\u2502 Standard shaft \u00d8
\n\u2502 \u2193
\n[Load via coupling]
\nNo radial force on shaft<\/div>\n

HIGH-RIGIDITY SHAFT \u2014 EP-AF<\/p>\n

Motor \u2500\u2500\u2500\u2500 Gearbox \u2500\u2500\u2500\u2500 \u2699 Gear
\n\u2502 \u2191
\n\u2502 Enlarged shaft \u00d8
\n\u2502 \u2190 Radial force F
\n\u2502 Bending stiffness
\n\u2502 \u221d \u00d8\u2074 (4th power)<\/div>\n
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Bending stiffness scales with the 4th power<\/strong> of shaft diameter \u2014 a small diameter increase produces a large stiffness gain<\/div>\n<\/div>\n<\/div>\n<\/div>\n

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Three Load Cases Where the Enlarged Shaft Makes the Critical Difference<\/h3>\n
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\u2460 Belt and Timing Belt Drives \u2014 Tension Creates Radial Force<\/strong><\/p>\n

A synchronous timing belt pulley or V-belt pulley mounted directly on the EP-AF output shaft creates a radial force equal to the vector sum of the tight-side and slack-side belt tensions. At 100 N\u00b7m output torque with a 50 mm radius pulley, tight-side tension alone reaches approximately 2,000 N. This radial force bends the output shaft. The enlarged shaft of EP-AF \u2014 with bending stiffness scaling with the fourth power of diameter<\/strong> \u2014 resists this bending with significantly lower deflection than a standard-diameter shaft of the same length, maintaining pulley alignment and protecting the gearbox output bearing from premature fatigue.<\/p>\n<\/div>\n

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\u2461 Spur and Helical Gear Direct Mounting \u2014 Mesh Force at Shaft End<\/strong><\/p>\n

When a spur or helical gear is mounted on the EP-AF output shaft end as part of an open gear pair \u2014 common in Korean packaging machines, printing presses, and automatic transport systems \u2014 the gear mesh transmits both tangential force (the torque-producing component) and radial separating force (from the pressure angle, typically 20\u00b0 for spur gears). For a 20\u00b0 pressure angle gear, the radial force is approximately 36% of the tangential force. The EP-AF enlarged shaft handles the combined bending and torsion loading without deflection that would alter the gear mesh centre distance and generate noise or premature tooth wear.<\/p>\n<\/div>\n

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\u2462 Eccentric Cam and Offset Loads \u2014 Gravity and Dynamic Bending<\/strong><\/p>\n

Eccentric cam drives, offset tooling heads, and cantilevered circular fixtures mounted on the output shaft end create both a static gravitational bending load (the weight of the cantilevered mass times its moment arm from the bearing) and a dynamic bending load as the mass rotates and the centrifugal force direction changes. The EP-AF enlarged shaft withstands the peak combined load \u2014 static plus dynamic \u2014 without shaft deflection at the cam profile that would introduce cam-follower tracking error and positioning deviation in the machine cycle.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

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EP-AF vs EP-AB \u2014 The Output Shaft Load Decision<\/h3>\n
\n\n\n\n\n\n\n\n\n\n\n
Load Condition at Output Shaft<\/th>\n\u2192 Choose EP-AF \u2605<\/th>\n\u2192 Choose EP-AB<\/th>\n<\/tr>\n<\/thead>\n
Load connection method<\/td>\nDirect shaft-end mounting \u2014 gear, pulley, sprocket, cam<\/td>\nCoupling or flange connection to load<\/td>\n<\/tr>\n
Radial force on output shaft<\/td>\nPresent \u2014 belt tension, gear mesh force, offset mass<\/td>\nMinimal \u2014 coupling handles misalignment, load is axial<\/td>\n<\/tr>\n
Separate output bearing housing<\/td>\nNot needed \u2014 enlarged shaft carries radial load directly<\/td>\nMay be needed if radial load is high<\/td>\n<\/tr>\n
Machine design intent<\/td>\nCompact: gearbox output shaft IS the driven shaft<\/td>\nTwo-shaft arrangement with coupling between them<\/td>\n<\/tr>\n
Precision \/ Efficiency \/ IP<\/td>\nIdentical: P0\/P1\/P2 \u00b7 \u226597% single-stage \u00b7 \u221210 to +90 \u00b0C \u00b7 IP65<\/td>\n<\/tr>\n
Gear ratios available<\/td>\nIdentical: single i=3\u201310, two-stage i=12\u2013100 (17 values)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
\u25b8 Key design rule: <\/span>
\nIf your load connects to the gearbox output shaft via a flexible coupling or through a rotary table flange where the shaft transmits only torque, specify EP-AB. If the load is mounted directly on the output shaft end and the shaft must also carry radial force and bending moment, specify EP-AF. The difference is not about precision grade \u2014 it is about shaft structural capacity.<\/span><\/div>\n<\/section>\n

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EP-AF and EP-AFX \u2014 Complete Specifications<\/h2>\n
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EP-AF Series \u2014 Full Torque Range<\/h3>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
EP-AF Specifications<\/td>\n<\/tr>\n
Torque (T2N)<\/td>\n14 \u2013 2,000 N\u00b7m<\/td>\n<\/tr>\n
Frame sizes<\/td>\nAF042\/060\/060A\/075
\n075A\/100\/100A\/140
\n140A\/180\/220<\/td>\n<\/tr>\n
Output shaft<\/td>\nEnlarged diameter \u2014 high rigidity<\/td>\n<\/tr>\n
Output flange<\/td>\nSquare (same as EP-AB)<\/td>\n<\/tr>\n
P0 backlash<\/td>\nSingle \u22641′ \u00b7 Two-stage \u22643′<\/td>\n<\/tr>\n
P1 backlash<\/td>\nSingle \u22643′ \u00b7 Two-stage \u22645′<\/td>\n<\/tr>\n
P2 backlash<\/td>\nSingle \u22645′ \u00b7 Two-stage \u22647′<\/td>\n<\/tr>\n
Single-stage ratios<\/td>\n3\/4\/5\/6\/7\/8\/9\/10<\/td>\n<\/tr>\n
Two-stage ratios<\/td>\n12\/15\/16\/20\/25\/28\/
\n30\/32\/35\/40\/45\/50\/
\n60\/70\/80\/90\/100<\/td>\n<\/tr>\n
\u0915\u094d\u0937\u092e\u0924\u093e<\/td>\n\u226597% (1-stage) \u00b7 \u226594% (2-stage)<\/td>\n<\/tr>\n
Temperature<\/td>\n\u221210 \u00b0C to +90 \u00b0C<\/td>\n<\/tr>\n
IP rating<\/td>\nIP65 standard<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

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EP-AFX Series \u2014 Reduced Torque Variant<\/h3>\n\n\n\n\n\n\n\n\n\n\n\n
EP-AFX Specifications<\/td>\n<\/tr>\n
Torque (T2N)<\/td>\n14 \u2013 1,200 N\u00b7m<\/td>\n<\/tr>\n
Frame sizes<\/td>\nAFX042\/060\/060A\/075
\n075A\/100\/100A\/140
\n140A\/180
\n(no AFX220)<\/em><\/td>\n<\/tr>\n
Output shaft<\/td>\nSame enlarged diameter as EP-AF<\/td>\n<\/tr>\n
Backlash grades<\/td>\nP0\/P1\/P2 \u2014 identical to EP-AF<\/td>\n<\/tr>\n
\u0917\u093f\u092f\u0930 \u0905\u0928\u0941\u092a\u093e\u0924<\/td>\nIdentical to EP-AF<\/td>\n<\/tr>\n
Efficiency \/ Temp \/ IP<\/td>\nIdentical to EP-AF<\/td>\n<\/tr>\n
When to choose AFX<\/td>\nOutput torque \u22641,200 N\u00b7m and AF220 frame is oversized for the machine design \u2014 AFX180 is the largest frame<\/td>\n<\/tr>\n
When to choose AF<\/td>\nOutput torque 1,200\u20132,000 N\u00b7m requires AF220; or AF is already specified and AFX offers no installation advantage<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
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Note:<\/strong> EP-AF and EP-AFX are not interchangeable at all frame sizes \u2014 AFX does not include the 220 mm frame. At frames 042\u2013180, both carry the same enlarged shaft geometry and are dimensionally compatible.<\/p>\n<\/div>\n<\/div>\n<\/div>\n

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\u25b8 Frame size note: <\/span>
\nEP-AF frame numbers (042, 060, 075, 100, 140, 180, 220) differ from EP-AB frame numbers (042, 060, 090, 115, 142, 180, 220). At the same body size level \u2014 e.g. “medium frame” \u2014 EP-AF075 is not the same dimensions as EP-AB090. Do not assume interchangeability between AF and AB frame numbers<\/strong>. Always compare dimensional drawings when specifying a replacement or alternative between these two series.<\/span><\/div>\n<\/section>\n

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Model Designation Guide \u2014 EP-AF and EP-AFX Part Numbers<\/h2>\n
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EP-AF 100 \/ 25 \/ S2 \/ P1<\/div>\n
EP-AFX 100 \/ 25 \/ S2 \/ P1 \u2190 AFX reduced-torque variant<\/div>\n
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EP-AF \/ EP-AFX<\/div>\n
Korea Ever-Power
\nHigh-Rigidity Shaft
\nSquare Flange Inline<\/div>\n<\/div>\n
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100<\/div>\n
Body diameter
\n100 mm
\n(AF scale, \u2260 AB115)<\/div>\n<\/div>\n
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25<\/div>\n
Gear ratio i=25:1
\n(two-stage)<\/div>\n<\/div>\n
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S2<\/div>\n
Output shaft
\nS1: smooth
\nS2: with keyway<\/div>\n<\/div>\n
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\u092a\u09401<\/div>\n
Backlash grade
\nP0 \u22641′ \/ P1 \u22643′
\nP2 \u22645′ (single-stage)<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

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Applications \u2014 Direct Shaft-End Load Mounting in Korean Industry<\/h2>\n
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Packaging Machines \u2014 Belt Drive Axes with High Tension<\/h3>\n

Korean flexible packaging machine OEMs building VFFS and HFFS machines use EP-AF for axes where a timing belt pulley is mounted directly on the gearbox output shaft \u2014 the cross-seal jaw drive, film feed roll drive, and registration correction axis. Timing belt tension at 50\u2013150 N\u00b7m output torque generates 1,000\u20133,000 N of radial force on the output shaft; the EP-AF enlarged shaft carries this load without deflection that would change the belt mesh pitch line distance and degrade registration accuracy. EP-AF075 and EP-AF100 at P1, ratios 5:1\u201325:1 cover the majority of Korean VFFS cross-seal axis requirements.<\/p>\n<\/div>\n

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Printing Machines \u2014 Open Gear Register Drives<\/h3>\n

Korean commercial and industrial printing machine register axes use open spur gear pairs where the EP-AF output shaft carries the driven gear directly \u2014 the gear mesh radial separating force adds to the torque loading on the shaft. Register axis accuracy requires that the gear centre distance remains constant through the print cycle; this demands a rigid output shaft that does not deflect under mesh loads. EP-AF100 P0 at i=10 to i=32 covers the speed reduction range of Korean offset and flexographic register correction drives.<\/p>\n<\/div>\n

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Textile Machinery \u2014 High-Speed Shaft-Mounted Drives<\/h3>\n

Korean textile machine warp beam drives, take-up roll drives, and yarn tension control axes mount large-diameter winding spools directly on the gearbox output shaft \u2014 the spool weight and winding tension both create radial force. At elevated speeds and large-diameter loads, the dynamic radial force from the rotating mass can exceed the static load. EP-AF140 P1 at two-stage ratios 20:1\u201350:1 covers the torque requirements of Korean industrial textile winding and take-up machinery.<\/p>\n<\/div>\n<\/div>\n

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Application by Load Type<\/h3>\n