EP-ADシリーズ 円形フランジ付き高精度インライン遊星歯車減速機（EP-AD047～EP-AD255）

The EP-AD series high-precision planetary gearbox is Korea Ever-Power's round circular-flange precision variant, addressing the specific installation requirements of rotary tables, hollow-shaft actuators, and circular bearing housings where a square flange introduces eccentric offset and misalignment risk. The circular output flange outer diameter acts as a precision machined datum — the flange pilots directly into the mating bore, centring the gearbox output shaft concentrically without dial indicator measurement or shimming. This self-centring property reduces installation time and eliminates the most common source of positioning drift in rotary table and turret applications: flange-interface eccentricity.

Beyond the flange geometry, EP-AD offers a gear ratio set that is unique in the Korea Ever-Power inline range: two-stage configurations include 21, 31, 61, and 91 — intermediate ratio values not available in the EP-AB square-flange series. These ratios allow engineers to reach specific output speeds from standard 1,450 rpm and 1,500 rpm 4-pole induction motor speeds without requiring a VFD, or to achieve precise speed matching in synchronised multi-axis systems where output RPM must match a defined process rate exactly. Performance of this high-precision planetary gearbox — P0 ≤1 arcmin backlash, ≥97% single-stage efficiency, −10 °C to +90 °C, IP65 — is identical to the EP-AB series.

Four Structural Advantages of the Circular Flange

Output Speed at Common Motor Inputs — EP-AD vs Nearest Standard Ratios

When the Intermediate Ratio Solves a Real Problem

CNC Turret Tool Changers — Round Bore, i=91

CNC lathe turret drives require a gear reducer that fits into the cylindrical turret housing bore with perfect concentricity — any eccentricity translates directly to tool positioning error. EP-AD's circular pilot flange centres the gearbox in the turret bore without measurement. The i=91 ratio, unavailable in any other EP inline series, allows a standard servo motor to drive the turret at precise indexing speeds for the tool-to-tool positioning cycle time requirements of Korean CNC turning centres.

Synchronised Assembly Lines — i=21/31 for Process Speed Match

Korean automotive and electronics assembly lines synchronise multiple rotary drives to a common line speed. Where the required rotary speed from a standard motor falls between two standard ratios, i=21 or i=31 closes the gap without a VFD. Eliminating the VFD on each synchronised station removes both the drive cost and the potential for VFD-to-VFD speed variation from independent control loops — a practical accuracy advantage on long synchronised lines with many stations.

Vertical Axis Rotary Drives — Round Flange + Self-Locking Stage

Vertical rotary positioners for heavy workholding require a self-locking secondary stage downstream of the precision planetary gearbox to hold position on power loss. EP-AD's round flange mates with the circular housing of a downstream worm gear self-locking stage more naturally than a square-flange unit — both components are rotationally symmetric about the vertical axis, eliminating the angular mismatch that square flanges introduce in vertical column-type positioner designs.

• ✔Round flange pilot diameter and bolt-circle verified by CMM — centring tolerance confirmed
• ✔Backlash grade (P0/P1/P2) certified per unit on shipping documentation
• ✔IP65 ingress test per IEC 60529 — dust-tight and water jet tested on every unit
• ✔Full-load efficiency test at rated torque per production batch
• ✔Material certificate and dimensional drawing supplied with delivery

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A complete round-flange inline planetary gearbox drive system often requires additional transmission components at the output side. The EP-AD circular flange is optimised for direct bore mounting — the rotary table, actuator, or positioner housing is the structural interface. Korea Ever-Power supplies the drive shaft and gearbox accessories that complete the system beyond the EP-AD output shaft.

For inline precision planetary gearbox selection within the Korea Ever-Power range: the EP-AB square flange precision planetary gearbox is the flat-mounting alternative when a square bolt pattern is required, and the EP-AE large flange planetary gearbox serves applications where both high overturning moment capacity and IP67 protection are specified.

Korea Ever-Power precision transmission products — gearboxes, CV shafts, worm reducers, and agricultural gearboxes

The EP-AD090 at P1, i=61 for the drive of a 500 mm 4th-axis rotary table. We needed exactly 23–24 rpm from a 1,450 rpm motor — i=61 gives 23.8 rpm, which matches our required table speed for heavy titanium face milling. i=50 (29 rpm) and i=70 (20.7 rpm) were both wrong for our process. The round flange piloted straight into our 92 mm H7 bore without any runout adjustment — table eccentricity measured 0.003 mm at the first assembly. Previously with a square-flange unit we spent 1.5 hours shimming. 20 months, 8 tables deployed, zero concentricity issues.

The EP-AD110 at P1, i=21 on our welding positioner line. We synchronise the positioner rotation to a 1,440 rpm motor running direct-online (no VFD to avoid welding interference) — i=21 gives 68.6 rpm, which matches our 4 m/min weld travel speed for the specific pipe diameter we're running. Without i=21 we had to use i=20 (72 rpm, 5% too fast) and adjust the wire feed manually to compensate. EP-AD eliminated the manual adjustment. The round flange also rotates to align the motor cable exit exactly where our cable management runs — could not do this with a square flange. 17 months, 22 positioner units deployed.

The EP-AD064 at P0, i=91 for a hollow-shaft cobot shoulder joint. The P0 grade meets our joint angular resolution spec; the round flange pilots into our 68 mm H6 actuator bore with 0.002 mm total runout — confirmed by our incoming inspection CMM. The i=91 ratio gives us the exact output speed to torque profile we need at the shoulder for 10 kg payload without running the motor at a thermally inefficient operating point. Korea Ever-Power provided the inertia ratio calculation confirming our 400W motor selection — their Korean-language support was faster and more technically detailed than any overseas supplier we've used.

The EP-AD090 at P2, i=31 on a synchronised automotive assembly conveyor index table. The i=31 ratio from a 1,450 rpm induction motor gives 46.8 rpm — exactly the table rotation speed that matches our 3.2-second station cycle time without a VFD. Removing the VFD on 12 tables saved us significant installation cost and eliminated the speed synchronisation variance between stations that we were getting from 12 independent VFD control loops. Important note: EP-AD only goes down to i=4 single-stage; if you need i=3, use EP-AB. We discovered this during specification but Korea Ever-Power's team flagged it before we ordered, which we appreciated.

QWhy does EP-AD not have single-stage ratios 3, 6, 8, and 9? Can I request these?

EP-AD single-stage ratios 4, 5, 7, and 10 reflect the gear tooth count combinations achievable within the round-flange AD series gear train geometry. The ratios 3, 6, 8, and 9 are not part of the EP-AD product specification and cannot be obtained by special order in this series. If your application requires ratio 3 (the most common case), 6, 8, or 9, use the EP-AB square-flange series instead. For applications needing a round flange and a ratio not available in EP-AD single-stage, consider whether the two-stage EP-AD range (which includes 16, 20, 21, 25, 31, 35, 40, 50, 61, 70, 91, 100) covers your required output speed from your motor's rated RPM.

QWhat bore tolerance does the round flange pilot diameter fit — H7, H6, or custom?

The EP-AD round flange pilot diameter is manufactured to a precision tolerance intended to fit standard H6 or H7 bore fits — the tolerances used in the majority of Korean rotary table, positioner, and actuator bore designs. The specific pilot diameter and its tolerance are given on the EP-AD dimensional drawing for each frame size, which Korea Ever-Power supplies with the order confirmation. If your bore is machined to a non-standard tolerance or a specific fit class other than H6/H7, contact Korea Ever-Power before ordering to confirm whether the standard pilot diameter is compatible or whether a tolerance deviation is required.

QAre EP-AD frames dimensionally interchangeable with EP-AB frames at the same body diameter?

No — EP-AD and EP-AB are different precision inline planetary gearbox series with different output flange geometries (round vs square) and different frame dimension scales (AD047/064/090/110/140/200/255 vs AB042/060/090/115/142/180/220). Even where the body diameter is the same (e.g. AD090 and AB090, both 90 mm body), the output flange dimensions, bolt patterns, and shaft dimensions may differ. Always verify dimensional drawings for both products before substituting one for the other. If you need to switch from round to square flange (or vice versa) on an existing machine, contact Korea Ever-Power for a dimensional compatibility check.

QWhy use a gear ratio of 21, 31, 61, or 91 instead of just using a VFD to trim the motor speed?

A VFD adds hardware cost, panel space, programming complexity, and a potential source of electrical noise. For applications with a fixed, unchanging output speed requirement — a conveyor, a positioner, an index table at a defined process speed — there is no operational advantage to variable speed control. Using an intermediate gear ratio to match the required output speed from a fixed-speed motor eliminates the VFD and all its associated costs and complications entirely. The VFD remains the right choice when variable output speed is operationally required; the intermediate gear ratio is the right choice when the output speed is fixed and a standard ratio simply doesn't match it.

QDoes the round flange of EP-AD increase the product's overall length compared to EP-AB?

The round flange itself does not significantly change the axial length of the gearbox compared to the square-flange EP-AB. The flange thickness is comparable; the difference is in the radial extent of the flange (round vs square bolt pattern), not the axial depth. However, when you factor in that EP-AD installs directly into a bore — rather than bolting to a flat surface with the gearbox overhanging — the effective installed length of the drive system can actually be shorter with EP-AD, because the gearbox body partially recesses into the bore rather than standing entirely above the mounting face. Check the dimensional drawing of the EP-AD frame you are considering against your specific machine structural envelope.