EP-WPBL/WPBF Series High Precision Right-Angle Planetary Gearbox — ≤8 Arcmin, IP65, 90° Output

The EP-WPBL/WPBF occupies a unique position in the Korea Ever-Power planetary gearbox portfolio: it is the only series that combines high precision backlash (≤8 arcmin), IP65 environmental sealing, and 90-degree right-angle output in a single unit. When your application demands both tight positional accuracy and perpendicular motor mounting, this is the series that eliminates the compromise.

Internally, the EP-WPBL/WPBF right-angle planetary gearbox uses the same upgraded gear quality and bearing class as the inline EP-PBL/PBF high precision series, with a hardened spiral-bevel input stage that redirects the motor axis by 90 degrees. Three frame sizes — 70, 90, and 120 — cover servo motor power from 50 W to 2,000 W across single-stage and two-stage configurations.

The bevel input stage adds a small amount of angular play compared to the inline EP-PBL/PBF, which is why the achievable backlash is ≤8 arcmin rather than ≤5 arcmin. This is a fundamental characteristic of right-angle planetary reducer architectures and represents the tightest backlash achievable in a 90-degree output configuration at this price point.

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Every right-angle planetary gearbox adds a spiral-bevel gear pair to redirect the motor axis. This bevel stage inherently introduces additional angular play that stacks with the planetary stage backlash. Understanding this relationship is essential for correct specification:

Korea Ever-Power minimises the bevel stage backlash contribution through precision spiral-bevel gear grinding (post-hardening), individual tooth contact pattern verification, and tapered roller bearing preloading. These measures compress the bevel-stage play to the theoretical minimum, ensuring the EP-WPBL/WPBF consistently meets the ≤8 arcmin specification rather than merely averaging it.

Building a right-angle planetary gearbox to ≤8 arcmin requires both the planetary stage and the bevel stage to be individually held to tighter tolerances than their backlash contribution targets. At Korea Ever-Power, the EP-WPBL/WPBF manufacturing process adds two critical steps beyond the standard right-angle EP-WPL/WPF production:

The EP-WPBL/WPBF integrates into the wider Korea Ever-Power precision drive platform:

“We integrate EP-WPBL70 units into our 6-axis collaborative robot arm joints. The 8-arcmin backlash delivers the repeatability our welding customers require, and the IP65 rating means we do not need additional sealing for automotive body-shop environments. Consistent quality across 200+ units delivered so far.”

“Our AGV fleet needed a right-angle gearbox that could handle precision path tracking in a semiconductor fab cleanroom. The EP-WPBF80 met both the accuracy requirement (≤8 arcmin) and the particle containment need (IP65). Path deviation dropped from ±12 mm to ±4 mm after the upgrade. Excellent result.”

“The EP-WPBL120 handles the 1.5 kW servo on our CNC press brake back gauge without issue. Positioning repeatability measured at ±0.04 mm over 10,000 cycles. Build quality is solid. Only suggestion: it would help to have a CAD model download on the website for faster integration into our machine design.”

“We tested three brands of right-angle precision gearbox for our palletising robot wrist joint. The EP-WPBL90 had the best price-to-backlash ratio and passed our 5,000-hour accelerated life test without measurable backlash degradation. Now standardised across our entire robot product line for the ASEAN market.”

“Specified EP-WPBF70 for our compact pick-and-place module. The square flange output simplifies mounting to our linear rail carriage, and the right-angle layout keeps the motor clear of the conveyor belt below. Backlash is within spec, noise is acceptable, and delivery to Bangkok was two weeks from order confirmation.”