BABR-serie uiterst nauwkeurige planetaire tandwielkasten — type met ronde flens (EP-BABR042 tot EP-BABR220)

The EP-BABR series high-precision planetary gearbox is the round circular-flange variant of Korea Ever-Power's flagship EP-BAB family, designed for applications where a cylindrical bolt-circle mounting interface fits the machine structure better than the square-flange arrangement of the standard EP-BAB. Beyond the flange geometry difference, EP-BABR offers the widest ratio range in the entire EP-BAB product family: single-stage extends to 14:1 and 20:1 — unavailable in the square-flange model — and two-stage extends all the way to 200:1, enabling output speeds as low as 15 rpm from a 3,000 rpm servo motor without cascading to a third reduction stage.

All seven frame sizes from EP-BABR042 through EP-BABR220 maintain the same core precision specification as the square-flange series: P1 grade backlash of ≤3 arcmin single-stage En ≤5 arcmin two-stage, single-stage efficiency ≥95%, noise below 65 dB(A), and full-body hardened alloy steel gears with ANSYS-validated tooth profile corrections. The round flange is particularly favoured in Korea's collaborative robot joint designs, hollow-shaft rotary actuators, and compact automation heads where the circular bolt pattern distributes clamping load symmetrically around the shaft centreline.

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Round Flange — Symmetric Load Distribution

The circular bolt-circle of EP-BABR distributes the clamping and reaction torque load symmetrically around the output shaft centreline. In square-flange designs, the four corner bolts are at unequal distances from the shaft axis, creating uneven bolt tension under high-torque reversals. The round flange's equidistant bolt pattern eliminates this asymmetry — particularly significant in the larger EP-BABR180 and EP-BABR220 frames where output torques up to 2,000 N·m would generate measurable flange deflection in asymmetric arrangements.

Round flanges also mount naturally into cylindrical housings and rotary joint cartridges — the mechanical format used in Korean collaborative robot joint modules, precision rotary stages, and hollow-shaft actuator assemblies where the gearbox body is inserted from one end of a tubular machine column.

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Extended Ratios — Single-Stage to 20:1, Two-Stage to 200:1

The standard planetary gear train achieves single-stage ratios up to 10:1 by constraining the ring gear and driving the planet carrier. BABR's extended single-stage ratios of 14:1 and 20:1 are achieved through a modified planet gear configuration that increases the ratio without adding a second stage — preserving the compact axial length of single-stage while covering an intermediate ratio range that previously required a two-stage unit.

Two-stage 200:1 enables a 3,000 rpm servo motor to drive an output axis at just 15 rpm within a single gearbox — eliminating the third reduction stage that would otherwise add housing length, cost, and backlash accumulation. For slow-speed positioning axes in automated guided vehicles, rotary kilns, and architectural shading drives, this is a decisive specification advantage over the 100:1 maximum of the square-flange model.

Slow-Speed Conveyor Positioning

Indexing conveyor drives requiring precise stop-position accuracy at 5–20 rpm output from a standard 3,000 rpm servo motor specify EP-BABR at 150:1–200:1 two-stage — achieving the necessary output speed range without variable frequency drive underfrequency derating that reduces available motor torque at very low speeds.

Medical Imaging Rotation Axes

CT scanner gantry and robotic surgery arm rotation drives require co-axial, vibration-free, sealed gear reducers. EP-BABR round flange integrates smoothly into the medical equipment housing circular bore without sharp corners that complicate sterilisation procedures, while the sealed lubrication prevents any particle generation near patient contact zones.

Rotary Kiln & Drum Drives

Industrial rotary kilns and tumble dryers running at 1–5 rpm from a 3,000 rpm motor require high reduction ratios in a compact, low-maintenance unit. EP-BABR at 200:1 eliminates the chain-drive intermediate stage traditionally needed between a standard planetary gear reducer and these ultra-slow machinery applications.

• ✔Backlash measured per unit — P1/P2 grade on certificate
• ✔Full-load torque test at 110% rated output
• ✔Noise check at 3,000 rpm — <65 dB(A) verified
• ✔Round flange face runout — concentricity to bore verified
• ✔Material cert + dimensional report with every shipment

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EP-BABR090 at i=20 for a collaborative robot elbow joint — the round flange allowed direct insertion into our 96 mm bore arm link without the adapter bracket we had with our previous square-flange supplier. Saved 22 mm of axial length which was exactly the margin we needed to meet the arm profile specification. 16 months operation across 45 units in production, zero backlash drift detected at quarterly checks.

EP-BABR115 at 140:1 two-stage for the steering axis of our 1,500 kg AGV. We needed 18 rpm output from a 2,500 rpm servo with ≤5 arcmin backlash — the 140:1 two-stage BABR hit both requirements in a single unit. Replaced a previous planetary-plus-worm two-unit arrangement, saved 60 mm of steering column height. 11 months, 24/7 warehouse operation, no maintenance calls.

EP-BABR142 on a precision indexing table — the round flange let us design a through-bore hollow shaft configuration with the bolt circle concentric to the 45 mm cable pass-through. With a square-flange unit this would have required an offset adapter that shifted our electrical through-bore away from the rotary centreline. Positioning accuracy: ±0.015° across 1.5 years of continuous 3-shift production. Excellent Korea Ever-Power application support throughout the design phase.

EP-BABR220 at 200:1 two-stage for a rotary kiln pre-drive — needed 15 rpm output from a standard 3,000 rpm motor without a third reduction stage or chain intermediate drive. The 200:1 single-unit solution reduced the drive train from three components to one and eliminated all chain maintenance. Two years operation in high-temperature kiln environment, sealed unit performed without any lubrication intervention. One point noted: specify the 200:1 ratio early — this configuration has 4–5 week lead time.

QIs the internal gear train of EP-BABR identical to EP-BAB?

Yes. EP-BABR and EP-BAB share the same internal planetary gearbox gear train, full-body hardened alloy steel gears, ANSYS-validated tooth profile corrections, and one-piece planet carrier and output shaft. The only differences are the output flange shape (round vs square), the availability of i=14 and i=20 single-stage ratios (BABR only), and the extended two-stage range to 200:1 (BABR only). Backlash, efficiency, noise, and all operating specifications are identical between the two series at equivalent frame sizes and ratios.

QWhy does BABR have ratios of 14:1 and 20:1 single-stage when standard planetary gearboxes top out at 10:1?

Standard planetary gearboxes achieve their ratio by constraining the ring gear and using the planet carrier as the output. The theoretical maximum for this arrangement with practical tooth counts is approximately 10:1 before tooth interference limits are reached. EP-BABR's 14:1 and 20:1 single-stage ratios are achieved through a modified compound planet configuration — using two sets of planet gears with different tooth counts on a shared carrier. This extends the achievable single-stage ratio without adding an additional reduction stage and its associated housing length and backlash contribution.

QAt 200:1 two-stage, is the ≤5 arcmin backlash specification still maintained?

Yes — two-stage P1 backlash of ≤5 arcmin applies regardless of specific ratio within the two-stage range, including 200:1. Backlash is an angular measurement at the output shaft, not dependent on the ratio value itself. At 200:1, ≤5 arcmin output shaft backlash corresponds to a very small angular movement of the input shaft (5 arcmin ÷ 200 = 0.025 arcmin input), which is negligible from the servo motor control perspective. Confirm the P1 grade at time of order for 200:1 configurations as these are non-stock items.

QWhat is the delivery lead time for non-standard ratios such as 140:1 or 200:1?

EP-BABR090 and EP-BABR115 in common two-stage ratios (25:1, 50:1, 100:1) are maintained in Korean warehouse stock with same-week dispatch. Extended ratios including 120:1, 140:1, 160:1, 180:1, and 200:1 are non-stock configurations with 4–6 week lead time from order confirmation. For production planning on Korean manufacturing lines, Korea Ever-Power recommends ordering extended-ratio units 6–8 weeks before the build date to absorb any scheduling variation. Contact our Korean sales team to confirm current lead times at time of enquiry.

QCan I switch my design from EP-BAB to EP-BABR without changing the servo motor adapter?

The input adapter plate at the servo motor end is identical between EP-BAB and EP-BABR at the same frame size and input flange type (T1/T2). The change between the two series affects only the output end — flange bolt pattern and geometry. If your machine design changes from square-flange to round-flange output, the servo motor adapter and motor connection remain unchanged; only the output-side mounting hardware and load structure interface need to be updated for the circular bolt pattern.