EP-WPL/WPF Series Right-Angle Planetary Gearbox — 90° Output for Space-Critical Installations

EP-WPL_WPF Series Right-Angle Planetary Gearbox
Korea Ever-Power EP-WPL/WPF Series
The right-angle planetary gearbox that redirects servo motor output by 90 degrees, reducing machine depth by up to 50%. Frame sizes 60, 80, and 120 cover motor power from 50 W to 2,000 W with rated output torque up to 220 N.m. Precision backlash from ≤13 arcmin (Frame 120 single-stage). IP54 sealed, 2,000-hour rated life. Available in round flange (EP-WPL) and square flange (EP-WPF) output.
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EP-WPL/WPF Right-Angle Planetary Gearbox Overview

The EP-WPL/WPF is the right-angle planetary gearbox variant of the Korea Ever-Power standard precision platform. It adds a hardened spiral-bevel input stage that redirects the motor axis by 90 degrees, producing an L-shaped drive configuration that dramatically reduces the axial footprint of the gearbox-motor assembly.

Where an inline planetary reducer requires the motor to extend directly behind the load, the EP-WPL/WPF right-angle planetary gearbox mounts the motor perpendicular to the output shaft. This is the defining advantage in machines where depth behind the driven axis is limited — conveyor frames, panel-mounted actuators, compact AGV wheel hubs, and vertical-axis winding mechanisms.

Three frame sizes — EP-WPL/WPF60, EP-WPL/WPF80, and EP-WPL/WPF120 — share the same planetary gear train as the EP-PL/PF inline series, with a precision spiral-bevel first stage added at the input. Ratios from 3:1 to 512:1, round flange (EP-WPL) and square flange (EP-WPF) outputs, and six input coupling options (OP1 through OP6) provide full application flexibility.

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EP-WPL/WPF Series Right-Angle 90 Degree Planetary Gearbox with round and square flange output

90°
Output Angle
220
N.m Max Torque
≤13′
Backlash (Fr120)

When Does Your Machine Need a Right-Angle Planetary Gearbox?

A right-angle planetary gearbox is the correct specification whenever the available depth behind the driven axis is insufficient to accommodate an inline motor-gearbox assembly, or when the motor must be oriented perpendicular to the load for mechanical, thermal, or maintenance reasons. The EP-WPL/WPF 90 degree planetary reducer addresses five installation constraints that inline units cannot solve:

EP-WPL_WPF Series Right-Angle Planetary Gearbox 1

  1. 1
    Machine depth is physically constrained
    The motor-gearbox assembly of an inline EP-PL120 extends approximately 200–280 mm behind the output face. The EP-WPL120 right-angle planetary gearbox redirects this length sideways, reducing the depth to the gearbox housing width alone — typically 40–50% less.
  2. 2
    The motor must clear an adjacent structure
    Panel-mounted actuators, wall-flush conveyor drives, and under-table positioning stages all require the motor to sit beside the output axis rather than behind it.
  3. 3
    Centre of gravity must stay low
    In AGV and mobile robot wheel drives, a right-angle planetary reducer keeps the heavy servo motor horizontal at hub height instead of extending vertically above the wheel.
  4. 4
    Vertical-axis drives with horizontal motor mounting
    Winding shafts, vertical indexing tables, and Z-axis lifters benefit from a motor mounted horizontally for easier cable routing and heat dissipation, while the output shaft points downward.
  5. 5
    Service access requires a side-mounted motor
    In food processing and packaging lines where the operator side must remain clear, a right-angle gearbox routes the motor away from the access zone.

If none of these constraints apply to your installation, the EP-PL/PF standard precision planetary gearbox delivers tighter backlash (≤8 arcmin vs ≤13–16 arcmin) and higher efficiency (≥96% vs ≥94%) at lower cost and weight.

Installation Envelope — Inline vs Right-Angle

The primary reason engineers specify a right-angle planetary gearbox is space. The diagram below compares the installation envelope of an inline EP-PL unit versus the EP-WPL right-angle variant for each frame size, assuming a typical servo motor length.

AXIAL DEPTH COMPARISON — MOTOR + GEARBOX ASSEMBLY

Frame 60

INLINE (EP-PL60)
~260 mm

RIGHT-ANGLE (EP-WPL60)
~147 mm
43% shorter

Frame 80
INLINE (EP-PL80)
~320 mm
RIGHT-ANGLE (EP-WPL80)
~172 mm
46% shorter

Frame 120
INLINE (EP-PL120)
~430 mm
RIGHT-ANGLE (EP-WPL120)
~210 mm
51% shorter

Axial depth measured from output face to motor end-cap. Typical 400–750 W servo motor assumed. Actual values depend on specific motor model.

The trade-off for this space saving is a modest increase in backlash (the bevel input stage adds angular play) and approximately 2% lower efficiency per stage compared to the inline EP-PL/PF. For applications where space is the primary constraint and ≤13–16 arcmin backlash is acceptable, the EP-WPL/WPF right-angle planetary reducer is the optimal solution.

Technical Specifications — All Frame Sizes

The following consolidated table covers all three EP-WPL/WPF frame sizes. All values are measured at 3,000 rpm input speed. Both round flange (EP-WPL) and square flange (EP-WPF) share identical performance data within the same frame.

EP-WPL60 Series Planetary Gearbox Dimension

EP-WPF60 Series Planetary Gearbox Dimension

Parameter EP-WPL/WPF(60) EP-WPL/WPF(80) EP-WPL/WPF(120)
Rated Output Torque (N.m) 13 – 40 27 – 110 63 – 220
Emergency Stop Torque (N.m) 26 – 80 54 – 220 126 – 440
Gear Ratios (1/2/3-stage) 3–10 / 9–40 / 64–512 3–10 / 9–40 / 64–512 3–10 / 9–40 / 64–512
Backlash — 1-Stage ≤16 arcmin ≤16 arcmin ≤13 arcmin
Backlash — 2-Stage ≤20 arcmin ≤20 arcmin ≤16 arcmin
Backlash — 3-Stage ≤23 arcmin ≤23 arcmin ≤20 arcmin
Efficiency (1/2/3-stage) ≥94% / 92% / 88% ≥94% / 92% / 88% ≥94% / 92% / 88%
Noise Level ≤70 dB(A) ≤73 dB(A) ≤75 dB(A)
Torsional Stiffness (N.m/arcmin) 2.3 5.8 14.5
Rated Life 2,000 hours
Protection Grade IP54
Motor Shaft Diameter (mm) 6 ≤ d ≤ 19 8 ≤ d ≤ 22 14 ≤ d ≤ 35
Weight (1/2/3-stage) 1.7 / 1.9 / 2.1 kg 4.4 / 5.0 / 5.5 kg 12 / 14 / 16 kg
Motor Power Range (W) 50 – 400 100 – 750 200 – 2,000

(1) Backlash tested at 2% of rated torque. (2) Noise measured at input speed 3,000 rpm, 1 m distance. (3) Radial and axial force refer to output distance position at 100 rpm. (4) Usage torque must not exceed rated torque; type-selection based on motor parameter.

Engineering Architecture — Spiral-Bevel Input Stage

The EP-WPL/WPF adds a hardened spiral-bevel gear pair at the input side of the standard planetary gear train. This bevel stage performs two functions simultaneously: it redirects the motor torque by 90 degrees, and it can provide an additional reduction ratio that extends the total available range.

The spiral-bevel teeth are case-hardened to HRC 58–62 and precision-ground to achieve smooth meshing with minimal vibration. Unlike straight-bevel or zerol-bevel alternatives, spiral-bevel gears maintain multiple teeth in contact at all times, distributing the load across a wider contact area and significantly reducing noise.

Because the bevel stage introduces a small amount of additional angular play, the minimum achievable backlash is wider than the inline EP-PL/PF: ≤13 arcmin for Frame 120 single-stage versus ≤8 arcmin for the equivalent inline model. This is a fundamental characteristic of all right-angle reducer designs, regardless of manufacturer.

⚠ Engineering Note: The bevel input stage also reduces overall mechanical efficiency by approximately 2% compared to the inline series. For applications where efficiency is critical and space permits inline mounting, the EP-PL/PF planetary gearbox is the preferred choice.
Planetary gearbox internal structure showing spiral bevel input stage and planetary gear train

Where the Right-Angle Configuration Excels

The EP-WPL/WPF 90 degree planetary reducer is purpose-built for installations where the motor orientation must be perpendicular to the output axis. Four representative application scenarios illustrate why engineers specify this configuration over inline alternatives:

Right-angle planetary gearbox application in AGV mobile robot and packaging conveyor drive

⚙

AGV / AMR Wheel Hub Drives

Autonomous guided vehicles require the servo motor to sit at wheel-hub height without extending above the vehicle chassis. The EP-WPL60 or EP-WPL80 right-angle planetary reducer mounts the motor horizontally inside the vehicle frame while the output shaft drives the wheel vertically — keeping the centre of gravity low and leaving the payload deck unobstructed. Pair with a precision drive shaft for articulating suspension linkages.

⚙

Food & Beverage Conveyor Positioning

Packaging lines run conveyors against walls or through machine frames that leave no room behind the drive roller. The EP-WPF80 right-angle gearbox with square flange output bolts directly to the conveyor side plate, routing the motor parallel to the belt direction. Washdown-resistant cabling and the IP54 seal handle splash zones between cleaning cycles.

⚙

Textile Winding & Warping Machines

Winding shafts in textile machinery rotate on a horizontal axis, but the machine frame depth at the drive end is occupied by yarn guides and tension sensors. The EP-WPL120 planetary reducer redirects the 1–2 kW servo motor downward or sideways, freeing the yarn path and simplifying thread-up procedures during bobbin changes.

⚙

Automated Assembly & Rotary Indexing

Multi-station rotary assembly tables require an under-table drive motor that does not increase the table height. The EP-WPL/WPF right-angle planetary gearbox sits beneath the table surface with the motor extending horizontally, keeping the work surface at ergonomic height while delivering precise angular indexing at ratios up to 100:1.

Manufacturing Quality & Korea Ever-Power Advantage

Korea Ever-Power precision gear grinding workshop for right-angle planetary gearbox production
Ever-Power gearbox testing centre verifying backlash and noise performance

The bevel gear stage in a right-angle gearbox demands tighter manufacturing tolerances than a standard inline unit. The spiral-bevel gear pair must mesh with precise tooth contact patterns to achieve low noise, high load capacity, and consistent backlash performance. At Korea Ever-Power, this requires three specialised processes:

◆ CNC Bevel Gear Cutting — Gleason-type spiral-bevel cutting machines produce tooth profiles with controlled spiral angle and pressure angle for optimal contact geometry.
◆ Case Hardening & Precision Grinding — After carburising to HRC 58–62, gear flanks are profile-ground to remove heat-treatment distortion and achieve surface roughness below Ra 0.8 μm.
◆ Tooth Contact Pattern Verification — Every bevel gear set is assembled and checked for contact pattern using marking compound before installation into the gearbox housing. Only gear sets with centred, well-distributed contact patterns pass inspection.
◆ 100% Backlash Testing — Every finished EP-WPL/WPF unit is tested at rated load to confirm backlash falls within the P1 or P2 specification before shipment.
◆ ISO 9001 Certified Production — Full traceability from raw material heat numbers through to final test certificates, manufactured at our Ansan-si facility in Gyeonggi-do, Korea.

Complementary Products & Ecosystem

Korea Ever-Power complementary products including planetary gearbox, drive shaft, and agricultural gearbox

The EP-WPL/WPF integrates seamlessly into the broader Korea Ever-Power drive-train platform:

◆ EP-PL/PF Series — Inline variant of the same standard precision platform. Specify when the installation has sufficient axial depth and tighter backlash (≤8 arcmin) is required.
◆ EP-WPBL/WPBF Series — High precision right-angle upgrade (≤8 arcmin, IP65) for AGV, robotics, and semiconductor applications that demand both 90° output and tighter positional accuracy.
◆ EP-HAB Series — Ultra-precision inline planetary gearbox (≤3 arcmin) with the highest torsional stiffness in the portfolio, designed for CNC machining centres and industrial robot joints.
◆ Agricultural Gearbox — Heavy-duty right-angle and inline gearboxes for farming, tillage, and off-highway equipment from the Ever-Power ecosystem.
◆ Worm Gear Reducer — Self-locking worm gearbox for conveyor, hoist, and positioning applications requiring holding torque without a separate brake mechanism.

What Our Customers Say

★★★★★

“Our AGV fleet uses EP-WPL80 right-angle gearboxes on all four wheel hub drives. The low-profile mounting keeps the centre of gravity 40 mm lower than the previous inline setup. After 8,000 hours of warehouse operation across 36 vehicles, we have had zero gearbox-related downtime events.”

Mr. Lee, Robotics Director — Incheon, Korea · AGV Systems Integrator
★★★★★

“We had 90 mm of depth behind our bottle-filling conveyor drive roller — no inline gearbox would fit. The EP-WPF60 solved it perfectly. Square flange bolted directly to the side plate, motor running parallel to the belt. Clean installation, and the noise is lower than we expected for a right-angle unit.”

Suzuki Packaging Solutions — Yokohama, Japan · Food & Beverage Machinery
★★★★☆

“Solid product for the price. We specified EP-WPL120 units on our warp beam drives. The 25:1 ratio at two-stage gives us the exact speed range we need. Backlash is acceptable for our tension control requirements. Would prefer an IP65 option for the dyeing department machines.”

Viet Textile Engineering — Binh Duong, Vietnam · Textile Machinery
★★★★★

“Replaced a European brand right-angle gearbox on our 6-station rotary indexing table. The EP-WPL80 at 20:1 delivers identical positioning performance at roughly half the procurement cost. Korea Ever-Power responded to our initial enquiry within 4 hours, and sample units arrived in Busan within a week.”

Mr. Choi, Mechanical Design Lead — Busan, Korea · Automated Assembly
★★★★★

“We build custom palletising machines for the Southeast Asian market. The EP-WPF80 right-angle planetary gearbox on our Z-axis lift saves 120 mm of vertical height compared to inline mounting. That let us lower the overall machine height to fit inside standard shipping containers. Great product, great support from the Ever-Power team.”

PT Karya Automation — Jakarta, Indonesia · Palletising & Material Handling

Frequently Asked Questions

▶ What is the efficiency difference between a right-angle and inline planetary gearbox?
The right-angle EP-WPL/WPF loses approximately 2% efficiency per reduction stage compared to the inline EP-PL/PF series. A single-stage right-angle unit achieves ≥94% versus ≥96% for inline. At three stages, the difference widens to ≥88% versus ≥90%. This efficiency loss occurs in the spiral-bevel input stage and is inherent to all right-angle planetary gearbox designs regardless of brand. Select the right-angle variant only when installation space demands the 90° motor orientation.
▶ Can the EP-WPL/WPF right-angle gearbox be mounted in any orientation?
Yes. The EP-WPL/WPF is designed for universal mounting orientation — horizontal, vertical output-up, vertical output-down, and any angle in between. The grease lubrication system does not rely on an oil sump, so there is no risk of lubrication starvation in non-horizontal positions. Ensure that the motor cable exit direction does not create a strain loop in the mounted position.
▶ Is the bevel input stage a spiral-bevel or hypoid gear?
The EP-WPL/WPF uses a spiral-bevel gear pair, not a hypoid gear. In a spiral-bevel set, the pinion and gear axes intersect at 90 degrees. In a hypoid set, the axes are offset, which provides higher torque capacity but introduces axial thrust loads that complicate bearing design. The spiral-bevel configuration used in the EP-WPL/WPF provides the best balance of smooth operation, low noise, and manufacturing precision for servo planetary gearbox applications.
▶ Why is the minimum backlash of the EP-WPL/WPF wider than the EP-PL/PF?
The EP-WPL/WPF adds a spiral-bevel gear pair at the input, and every gear mesh introduces a small amount of angular play. The bevel stage alone contributes approximately 5–8 arcmin of backlash that stacks with the planetary stage. As a result, the EP-WPL Frame 60/80 achieves ≤16 arcmin (vs ≤8 arcmin for EP-PL), and EP-WPL Frame 120 achieves ≤13 arcmin (vs ≤5 arcmin for EP-PL120). If your application requires ≤8 arcmin in a right-angle configuration, consider the EP-WPBL/WPBF high precision right-angle series.
▶ What servo motors are compatible with the EP-WPL/WPF Frame 80?
The EP-WPL/WPF Frame 80 accepts motor shaft diameters from 8 mm to 22 mm, covering servo motors from 100 W to 750 W. This includes most models from Mitsubishi (HG-KR/HG-SR series), Panasonic (MINAS A6), Yaskawa (SGM7J), Siemens (1FK7), Delta (ECMA), and other mainstream brands. Six input coupling options (OP1 through OP6) ensure compatibility with different shaft and keyway configurations. Contact our engineering team with your specific motor model for a confirmed adapter recommendation.
▶ How quickly can Korea Ever-Power deliver EP-WPL/WPF units to Southeast Asia?
Standard frame sizes and common ratios are typically available ex-stock from our Ansan-si warehouse with a lead time of 5–10 business days to most Southeast Asian destinations including Vietnam, Thailand, Indonesia, and the Philippines. Custom configurations (special shaft, non-standard ratio, or private-label) require 15–20 business days. All shipments include full test certificates and packing suitable for ocean freight or air freight as required.

Specify Your EP-WPL/WPF Right-Angle Planetary Gearbox

Tell us your motor model, required ratio, available installation depth, and output torque. Our engineers will confirm the optimal EP-WPL or EP-WPF right-angle configuration within one business day.

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