EP-AF Series High-Rigidity Output Shaft Inline Planetary Gearbox (EP-AF042 to EP-AF220, and EP-AFX Variant)

The EP-AF series high-rigidity inline planetary gearbox differs from the EP-AB square-flange series in exactly one structural dimension: the output shaft diameter. EP-AF uses an enlarged diameter output shaft whose increased cross-section delivers substantially higher bending stiffness and radial load capacity — 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.

All other specifications — backlash grades P0/P1/P2, single-stage efficiency ≥97%, operating temperature −10 °C to +90 °C, IP65 protection, and the complete ratio set from i=3 to i=100 two-stage — are identical to EP-AB. The EP-AFX variant covers the same specification at a reduced maximum torque of 1,200 N·m in ten frame sizes, for applications where the full 2,000 N·m of EP-AF220 is not required.

Three Load Cases Where the Enlarged Shaft Makes the Critical Difference

EP-AF Series — Full Torque Range

EP-AFX Series — Reduced Torque Variant

CNC Machine Tool Cam Stations

Korean CNC multi-spindle turning centres and cam-driven transfer machines use EP-AF for the cam shaft drive — the cam profile imparts cyclic radial forces on the output shaft as the follower tracks the profile. The EP-AF enlarged shaft resists the peak follower force without shaft deflection that would alter the cam motion law and introduce timing errors in the machining cycle.

Conveyor and Transport Chain Drives

Korean automated logistics and assembly conveyor systems mounting a sprocket directly on the EP-AF output shaft experience chain tension as a radial force — particularly on return-path rollers where the tight-side tension acts directly on the shaft end. EP-AF100 P2 at ratios 10:1–40:1 covers the majority of Korean conveyor chain drive speed-reduction requirements, eliminating the need for a separate sprocket shaft and bearing housing.

Agricultural Machinery Drives

Korean precision agriculture equipment — fertiliser spreader disc drives, seeder roller drives — mounts the spreading disc or seeder roller directly on the EP-AF output shaft. The disc or roller weight plus the reaction force from distributing material creates a combined radial and axial load that the high-rigidity shaft absorbs, maintaining disc position geometry and distribution uniformity across the full working width.

• ✔Output shaft diameter and runout verified — enlarged shaft geometry confirmed against drawing
• ✔Backlash grade (P0/P1/P2) certified per unit on shipping documentation
• ✔Full-load efficiency test at rated output torque per production batch
• ✔IP65 ingress test per IEC 60529 — every unit
• ✔Material certificate and dimensional report with each delivery

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EP-AF100 P1, i=20 for the cross-seal jaw drive on our VFFS machine — direct timing belt pulley, 90 mm radius, running at 120 seals/min. Previously we had a standard-shaft precision gearbox on this axis with a separate outboard bearing to carry the belt tension. The EP-AF eliminated the outboard bearing, shortened the jaw drive assembly by 85 mm, and removed one additional bearing from the PM schedule. At 18 months and 6 machines, no output bearing failures and no belt alignment deviations. The Korea Ever-Power team confirmed the belt tension radial force calculation before we finalised the specification — that was the deciding factor in our supplier choice.

EP-AF075 P0, i=25 for the register correction axis on an offset printing press — direct spur gear mounting. We had been using an EP-AB at the same frame with a flexible coupling between the gearbox and the gear shaft; we were getting backlash-induced register variation at high speed reversals. Switching to EP-AF with direct gear mounting eliminated the coupling compliance. The P0 grade (≤1 arcmin) held the register within our ±0.05 mm specification consistently across a 12-hour production run. Output shaft runout confirmed at 0.004 mm by our incoming inspection. 23 months, 4 machines, zero register deviation incidents.

EP-AF140 P1, i=35 for a warp beam drive on an industrial weaving machine — 450 mm diameter warp beam mounted directly on the output shaft, running at 41 rpm from a 1,450 rpm motor. The beam weight (68 kg) and winding tension create a substantial radial moment on the output shaft. Previous standard-shaft gearboxes on this application required replacement at intervals of 8–14 months due to output bearing fatigue. EP-AF has now run 27 months on 8 machines without a single output bearing replacement. The enlarged shaft clearly makes the difference in this application — we should have specified it from the start.

CV Joint Drive Shafts

For EP-AF configurations where the output shaft drives a load at an angular or parallel offset — belt drive systems where the driven shaft is not coaxial with the EP-AF output, or dual-drive configurations on large rotary tables — precision CV joint drive shafts transmit the output torque through the offset without additional radial loading on the EP-AF shaft end, complementing the high-rigidity shaft design.

Worm Gear Reducers

For vertical EP-AF output axes with direct-mounted belt pulleys or chain sprockets — hoist and lift mechanisms where the load must be held on power-off — a downstream self-locking worm gear reducer provides gravity load holding at any position. Worm reducers also extend the EP-AF total ratio range beyond the two-stage maximum i=100 for very low speed applications.

Agricultural Gearboxes

For Korean precision agriculture applications where EP-AF drives a fertiliser spreader disc, seeder roller, or sprayer pump directly — the enlarged shaft carries the disc or roller weight as a radial load — downstream bevel and spiral-bevel agricultural gearboxes from Korea Ever-Power provide multi-output PTO configurations, extending the EP-AF drive train to distribute power across multiple working heads in a single agricultural machine pass.

क्यूWhat exactly does "high-rigidity output shaft" mean — is it a different material or just a larger diameter?

The high-rigidity output shaft of EP-AF achieves its increased stiffness through an enlarged cross-sectional diameter compared to the standard shaft of a comparable EP-AB frame. Shaft bending stiffness (resistance to deflection under lateral load) is proportional to the fourth power of the diameter — a 25% larger diameter more than doubles the bending stiffness. The material specification is not different from the EP-AB series; the stiffness gain comes entirely from the diameter increase. The specific shaft diameter for each frame size is given on the EP-AF dimensional drawing provided by Korea Ever-Power at the time of order confirmation.

क्यूIf I mount a belt pulley on the EP-AF output shaft, do I need to specify any additional shaft support or outboard bearing?

For the majority of standard belt drive applications within the rated radial load of EP-AF, no additional shaft support is required — the enlarged shaft and its integrated output bearings carry the radial load directly. However, the actual radial force at the shaft end depends on the belt tension (function of transmitted torque, pulley radius, and belt type), the distance from the gearbox face to the centre of the pulley (the moment arm), and the operating speed. Korea Ever-Power provides a pre-order radial load calculation review for each application — confirm your pulley dimensions, belt type, and torque with the Korea Ever-Power Korean application team to receive a specific confirmation that your configuration is within the EP-AF shaft's rated capacity.

क्यूAre EP-AF and EP-AB dimensionally interchangeable at the same frame number?

No. EP-AF uses a different frame number scale from EP-AB — EP-AF has 075, 100, 140 as middle frames where EP-AB has 090, 115, 142. Even where the numbers look similar (e.g. AF180 and AB180), the output shaft diameter is different by design (EP-AF has a larger shaft), so the two series are not physically interchangeable. If you are replacing an EP-AB with an EP-AF to gain radial load capacity, verify the dimensional drawing of the EP-AF frame you are switching to — the output shaft bore in the load (pulley, gear, cam) must match the EP-AF enlarged shaft diameter.

क्यूCan I specify P0 (≤1 arcmin) on EP-AF for a direct belt-drive precision servo axis?

Yes — P0 is available on EP-AF across all ratios and all frame sizes, identical to EP-AB. However, note that in a belt-driven servo axis, the total positioning error at the load includes both the gearbox backlash and the belt's own compliance and backlash at the pulley-tooth engagement. Specifying P0 on the gearbox reduces the gearbox contribution to nearly zero, but the belt transmission introduces its own position error component. If the overall axis positioning accuracy requires sub-arcminute performance, confirm that the belt drive specification is consistent with this requirement — the gearbox alone at P0 is not the whole system error budget.

क्यूWhen should I choose EP-AFX instead of EP-AF?

Choose EP-AFX when your application output torque is within 1,200 N·m and the AF220 frame size (the only frame exclusive to EP-AF) is unnecessarily large for your machine design. EP-AFX042 through EP-AFX180 are dimensionally identical to their EP-AF counterparts — the same enlarged shaft, same flange, same ratios and grades. The difference is solely the maximum torque rating (1,200 N·m vs 2,000 N·m) and the absence of the 220 mm frame in EP-AFX. If you are designing around the EP-AF220 frame specifically, EP-AFX cannot substitute.