EP-TNF Round-Flange Output Helical Planetary Gearbox

ال EP-TNF round-flange helical planetary gearbox is designed for applications where the load interface is a bolt circle, not a shaft bore. A robot arm link that fastens to the gearbox output face, a CNC rotary table whose housing pilot register seats the gearbox, a direct-drive indexing head — all require a bolt-circle flange at the gearbox output, not a shaft end that must then be coupled to the load. Six frame sizes (060–220 mm) cover output torques from 50 N·m to 2,000 N·m with ratios i=3 to i=100. Two backlash grades — P1 (≤5 arcmin) and P2 (≤7 arcmin) — cover Korean servo positioning and speed-control applications respectively. The 042 frame is not available in TNF; the minimum is 060.

Round-flange precision planetary gearbox · Direct robot arm / rotary table interface · IEC / NEMA universal adapter · Korea warehouse stock

Every coupling in a servo drive chain is a maintenance item and a backlash source. A bellows coupling starts at 0.2–0.5 arcmin new and grows with torsional fatigue cycles; a jaw coupling starts at 0.5–1.5 arcmin and grows faster. EP-TNF's bolt-circle output replaces the coupling with a fixed structural interface. The gearbox backlash certificate value is the total system backlash — there is no coupling contribution to estimate, measure, or periodically re-tighten. For a system where 5 arcmin total backlash is the budget, EP-TNF P1 delivers that as a single measured, certified value.

The output flange face and pilot register are ground after full gearbox assembly, referenced to the actual rotation axis. Runout ≤0.02 mm TIR is achieved because the grinding datum is the assembled bearing pair — not a nominal design axis. The pilot register locates the mating hub or table housing concentrically with the rotation axis; the bolt circle provides axial retention and torque transmission. Each time the gearbox is re-installed in the same pilot bore, concentricity is restored automatically without dial indicator realignment.

A cantilevered robot arm or rotary table fixture applies a bending moment at the output interface. On a shaft-output gearbox, this moment is reacted by the output shaft bearing span — limited by the shaft length inside the housing. On EP-TNF, the moment is reacted by the bolt circle at the full flange face diameter (Ø80–292 mm depending on frame), distributed across all flange bolts. The effective lever arm for moment resistance is the flange radius — larger than the shaft bearing span at equivalent torque rating, resulting in higher tilting moment capacity.

The helical planetary gear set inside EP-TNF is identical to EP-TM at the same frame size. Efficiency ≥97% L1 / ≥94% L2 is the same — no efficiency penalty from the flange interface. The slight backlash difference (EP-TNF P1 ≤5 arcmin versus EP-TM P1 ≤3 arcmin) reflects the flange bearing geometry rather than lower gear precision. For applications comparing EP-TM + coupling versus EP-TNF direct, the EP-TNF option typically results in lower total system backlash because it eliminates the coupling contribution entirely.

The EP-TNF output flange dimensions are compatible with ISO 9409-1 robot wrist interface standard at several frame sizes — TNF060 (Ø80 mm) matches size 50, TNF090 (Ø116 mm) matches size 80. This allows standard end-effector tool change adapters to mount directly to the EP-TNF output face in robot integration applications, without any custom adapter ring. Korea Ever-Power confirms the specific bolt circle and pilot register dimensions against the required ISO 9409-1 size designation at enquiry, same day, at no charge.

The backlash measurement on the EP-TNF delivery certificate is taken at the output flange face, at ±3% T₂ₙ preload, referenced to the actual flange rotation axis. This is the same reference point as the machine interface — the measured value directly enters the system error budget without any transformation. For shaft-output gearboxes, the backlash is measured at the shaft end; the machine designer must then add coupling compliance to get the total system backlash. EP-TNF's flange measurement eliminates this additional calculation step.

Korean collaborative robot manufacturers (Rainbow Robotics, Doosan Robotics) specify large-diameter output flanges on the shoulder and elbow joints to directly interface with the aluminium arm extrusion. TNF090/115 at i=25–50 P1 is the standard configuration. The flange face acts as the structural support surface for the arm link — no separate adapter ring required, which reduces arm mass and the inertia calculation at each joint. See the robot joint drive guide →

Korean CNC machine tool builders (Doosan Machine Tools, Hwacheon) use TNF115/142 at i=50–100 for the B and C rotary table axes. The oversized flange (Ø152/Ø186 mm) provides the structural stiffness required to hold workpiece fixtures at the table face under cutting forces. The ground flange face (runout ≤0.02 mm) defines the table face perpendicularity — directly affecting the 5-axis angular calibration accuracy.

Equipment Front End Modules in Korean fab tool sets (used at Samsung Display, LGD) use TNF060/090 for the wafer transfer robot rotation axis. The small TNF060 (Ø80 mm flange, 1.3 kg) fits within the EFEM footprint constraint while providing the P1 backlash needed for precise wafer slot alignment. The sealed grease eliminates the particle generation from oil lubrication that would compromise cleanroom ISO Class 3 requirements.

Korean fibre laser cutting machines (Han's Laser Korea, Bystronic Korea) use TNF090 or TNF115 for the rotary axis that indexes tubular workpieces. The flange output mounts directly to the chuck backplate — the ground flange face ensures chuck face perpendicularity to the rotary axis, which determines cut perpendicularity on round tube profiles. At i=25–50, the servo can produce high-speed index moves (360°/0.2 s) for efficient tube processing cycles.

Korean medical device OEMs (GE Healthcare Korea, Siemens Healthineers Korea operations) use TNF090/115 in CT scanner gantry rotation drives. The large-diameter flange output provides the structural bearing for the rotating gantry ring — the low noise (≤60–63 dB) is specified by hospital installation requirements, and the sealed grease eliminates the oil maintenance access difficulty in the closed gantry housing.

Korean machining centre APC systems rotate 180° to swap loaded and unloaded pallets. TNF115/142 at i=20–40 drives this rotation via the output flange mounted directly to the APC turntable hub — no shaft, no coupling, no coupling alignment procedure. The TNF flange face is the precision interface that determines pallet position accuracy at the machining spindle. Pallet repeatability depends directly on output flange runout: TNF's ≤0.02 mm flange face runout contributes <0.02 mm to APC positioning error.

سؤال
How do I calculate whether the EP-TNF output flange can handle the tilting moment from my robot arm's end-effector load?

The tilting (overturning) moment M_tilt at the output flange is calculated as: M_tilt = F_load × L, where F_load is the total force (gravity + dynamic) from the arm and payload, and L is the distance from the output flange face to the centre of gravity of the supported load. Check M_tilt against the EP-TNF's permissible tilting moment, which Korea Ever-Power provides in the dimensional datasheet for each frame. Alternatively, calculate the equivalent radial force at the shaft centreline: F_r_equiv = M_tilt / (flange face to bearing centreline distance), and check against the permissible radial force F_{r_max} from the specification table using the position factor method described in the radial load calculation guide. Korea Ever-Power performs this calculation for any specific application on request.

سؤال
My Korean COBOT design uses a standard ISO 9283 flange pattern. Does the EP-TNF output flange match this standard directly?

The EP-TNF output flange dimensions are compatible with ISO 9283 mechanical interface specifications for most frame sizes, but the bolt circle diameter and pilot register diameter must be confirmed against your specific ISO 9283 size designation. Korea Ever-Power provides a detailed dimensional drawing for any EP-TNF model on request — provide the ISO 9283 interface size and the motor model number, and the drawing will confirm compatibility or identify any adapter ring requirement. For Korean COBOT OEMs with established flange patterns, custom output flanges with non-standard bolt circles and pilot register diameters are available with a 3–4 week lead time.

سؤال
Is the EP-TNF inertia value the same as the EP-TM for the same frame and ratio? Does the heavier flange output affect servo inertia matching?

The EP-TNF's output flange is slightly heavier than the EP-TM's output shaft section, and this difference is reflected in a marginally higher J_gearbox_input value. However, since J_gearbox_input is reflected through the square of the gear ratio (J_input = J_gearbox_input / i² is not the correct formulation — the input-referred inertia of the gearbox body itself adds directly to J_motor at the motor shaft), the practical impact depends on whether the flange's additional inertia is relevant for your application. For standard servo axes with i ≥ 5, the flange mass difference between TNF and TM adds less than 5% to the total motor-referred inertia — negligible for inertia matching purposes. Use the J_gearbox_input value from the Korea Ever-Power EP-TNF datasheet for precise calculations. The inertia matching methodology is explained in the inertia matching guide.

سؤال
We need P0 (≤1 arcmin) backlash on a flange-output gearbox for a Korean wafer handling robot. Which Korea Ever-Power series covers this?

The EP-TNF series provides P1 (≤5 arcmin) as the highest precision grade available in this configuration. For P0 (≤1 arcmin) with flange output, the correct specification is the EP-TEG ultra-precision series — which provides ≤1 arcmin as standard across all ratios and frame sizes, and is available with flange output. The EP-TEG is designed specifically for Korean semiconductor and precision optics applications where P0 grade is a hard requirement, not an option. For wafer handler θ-axis applications, the EP-TEG in combination with an encoder feedback loop typically achieves ≤0.1 arcmin effective repeatability at the output flange.

EP-TNF115 P1 i=50 dual-stage for the C-axis of our new 5-axis CNC machining centre. The Ø152 mm output flange bolts directly to the rotary table housing — no coupling, no adapter ring. Previous design used EP-TM with a bellows coupling; the coupling grew to 0.8 arcmin wear after 8,000 hours and we had to compensate in the controller. TNF flange-direct: 18 months in service, backlash measurement unchanged at 4.7 arcmin versus 4.8 arcmin delivery certificate. Korea Ever-Power confirmed direct fit to our table housing pilot bore, H7/h6 fit, same day as enquiry.

EP-TNF090 P1 i=25 for the J4 wrist roll joint on a 6-axis cobot we build for Korean general industry. The Ø116 mm flange outputs directly to the forearm link bolt pattern — no coupling, no adapter flange. At i=25 the inertia ratio J_load/J_motor = 0.12:1, which tunes instantly in the servo drive. Output runout measured 0.018 mm TIR after assembly — within the ≤0.02 mm specification. At ≤3 kg payload the joint works flawlessly over 12 months and 3 cobot units with zero warranty issues.

EP-TNF180 P2 i=80 dual-stage for horizontal single-axis solar tracker slew drive on a 2 MW utility farm in Jeonbuk. The Ø240 mm output flange bolts to the tracker arm hub directly. At Fr=14,800 N radial capacity, the gearbox handles full wind-load on 8-metre tracker arms without additional support bearings. IP65 sealing and −10°C minimum temperature have performed through two Korean winters. 68 units installed across the site, zero failures at 22 months. Stainless fastener option was supplied for coastal salt environment.