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EP321L2 Planetary Gearbox — Direct Replacement for Trasmital Bonfiglioli 321L2
The Ever Power EP321L2 is a In-Line planetary gearbox engineered as a dimensional and performance replacement for the Trasmital Bonfiglioli 321L2. Built on a two-stage architecture with a nominal ratio window of 12:1 to 40:1, it delivers approximately 260,000 Nm of nominal output torque while preserving the original mounting footprint so field retrofits are straightforward. Learn more about our gearbox programs.
1. Product Overview
The EP321L2 belongs to Ever Power's heavy-duty planetary reducer line developed specifically as a form-fit-function alternative to Italian-built 321-frame originals. Industries routinely deployed on this frame include:
Core strengths at a glance: drop-in mounting interface, carburized and ground planet gears, modular stage stacking, IP65 shaft sealing, bi-directional torque rating, and synthetic-oil-ready housing ventilation. Every unit leaves the factory with a serial number, run-in report, and torque-versus-speed certificate.
2. Technical Parameters
| Parameter | EP321L2 Specification |
|---|---|
| Frame Size | 321 |
| Configuration | in-line (coaxial) output |
| Number of Planetary Stages | 2 |
| Nominal Ratio Window | 12:1 to 40:1 |
| Nominal Output Torque (T2N) | up to 260,000 Nm |
| Peak Torque (T2max) | 2.0 to 2.5 x T2N |
| Max Input Speed | 3,000 rpm (continuous 2,000 rpm) |
| Mechanical Efficiency | 97% per stage (in-line); 94% per stage (right-angle) |
| Backlash (Standard / Precision) | <15 arcmin / <6 arcmin |
| Bearing Life L10h | 20,000 h (nominal load) |
| Oil Sump Temperature | -20 C to +95 C (synthetic to +110 C) |
| Ingress Protection | IP65 shaft seals, IP55 breather |
| Approximate Dry Weight | 2,400 kg |
| Paint System | C4M (coastal medium) epoxy + polyurethane |
| Mounting Options | Flange, foot, shaft-mount, torque arm |
3. Working Principle and Structure
The EP321L2 uses an epicyclic gear train in which a central sun gear drives three or four planet gears held by a rigid planet carrier. The planets orbit inside a stationary internal ring gear, with output taken from the carrier shaft. Torque is split across the planet set so each tooth carries only a fraction of total load, yielding very high torque density per unit mass. In multi-stage variants, successive planet sets are cascaded inside the same housing, multiplying the total ratio while keeping the output coaxial with the input.
The EP321L2 is built around a one-piece forged ductile-iron housing, a solid forged planet carrier, carburized and ground alloy steel gears, taper-roller output bearings, and twin-lip nitrile rotary seals with a dust-exclusion ring.
4. Core Advantages
5. Structure and Material Craftsmanship
Every EP321L2 housing is cast from GGG50 ductile iron and stress-relieved before machining to keep critical bores within 0.02 mm of tolerance over the full operating temperature range. Planet and sun gears use 20CrMnMo alloy steel, case-carburized to a surface hardness of HRC 58-62 over a 1.0 to 1.6 mm case depth, then profile-ground to ISO quality grade 6. The planet carrier is forged from SCM440 and induction hardened at bearing seats. Output shafts are manufactured from 42CrMo4V quenched-and-tempered steel, with keyways broached to ISO P9 and splines cut to DIN 5480. Bearing selection pairs SKF or NSK taper rollers on the output with precision deep-groove bearings on the input, sized for bucket-strike shock loads with a 1.6 minimum safety factor. The internal ring gear is a nitrided 34CrAlNi7 sleeve pressed into the housing, providing long wear life without weakening the casing. Read more about our factory capability.
6. Typical Application Scenarios
7. Selection Guide
To select the correct EP321L2 configuration, please confirm the following parameters. Our application engineers will size the unit against your duty cycle and environmental conditions.
- Application type: conveyor, mixer, winch, slew, pump, extruder, or other.
- Continuous output torque and peak torque in Nm, with expected duty cycle (hours per day, starts per hour).
- Input and output speed or the required reduction ratio.
- Input side: solid shaft coupling, IEC / NEMA motor flange, or hydraulic motor interface.
- Output side: solid shaft, hollow shaft with shrink disc, splined shaft, or flanged.
- Mounting orientation: horizontal, vertical up, vertical down, or inclined (specify angle).
- Ambient conditions: temperature range, humidity, dust, corrosive atmosphere, ATEX zone.
- Radial and axial external loads on the output shaft with lever arm if applicable.
- Service factor target and expected L10h bearing life.
- Accessories needed: backstop, brake, motor, cooling, oil heater, sensors.
8. Brand Cross-Reference and Positioning
The table below shows the 321-frame variants currently catalogued, with highlighted row indicating the present product:
| Original Reference (Trasmital Bonfiglioli) | Ever Power Replacement |
|---|---|
| Trasmital Bonfiglioli 321L1 | EP321L1 |
| Trasmital Bonfiglioli 321L2 | EP321L2 |
| Trasmital Bonfiglioli 321L3 | EP321L3 |
| Trasmital Bonfiglioli 321L4 | EP321L4 |
| Trasmital Bonfiglioli 321R4 | EP321R4 |
We also cover the full Trasmital Bonfiglioli frame range from 300 to 321. The Ever Power replacement code simply prefixes EP to the original model, for example 309R3 becomes EP309R3. Complete frame catalogue:
- 300: L1, L2, L3, L4, R2, R3, R4 → EP300(suffix)
- 301: L1, L2, L3, L4, R2, R3, R4 → EP301(suffix)
- 303: L1, L2, L3, L4, R2, R3, R4 → EP303(suffix)
- 305: L1, L2, L3, L4, R2, R3, R4 → EP305(suffix)
- 306: L1, L2, L3, L4, R2, R3, R4 → EP306(suffix)
- 307: L1, L2, L3, L4, R2, R3, R4 → EP307(suffix)
- 309: L1, L2, L3, L4, R2, R3, R4 → EP309(suffix)
- 310: L1, L2, L3, L4, R2, R3, R4 → EP310(suffix)
- 311: L1, L2, L3, L4, R2, R3, R4 → EP311(suffix)
- 313: L1, L2, L3, L4, R2, R3, R4 → EP313(suffix)
- 315: L1, L2, L3, L4, R3, R4 → EP315(suffix)
- 316: L1, L2, L3, L4, R3, R4 → EP316(suffix)
- 317: L1, L2, L3, L4, R3, R4 → EP317(suffix)
- 318: L1, L2, L3, L4, R4 → EP318(suffix)
- 319: L1, L2, L3, L4, R4 → EP319(suffix)
- 321: L1, L2, L3, L4, R4 → EP321(suffix)
Matched motor supply: Ever Power additionally offers IE3, IE4, and IE5 premium-efficiency three-phase induction motors, explosion-proof Ex d e II motors, brake motors with spring-set DC brakes, and inverter-duty motors from 0.55 kW to 315 kW. Ordering the gearbox together with the matched motor simplifies logistics and guarantees flange-to-flange alignment at commissioning. Explore our full replacement catalogue.
9. Quality Certification and Service Commitment
After-sales service: response within 12 working hours, remote troubleshooting support, on-site commissioning available in major global ports, spare parts kits pre-packaged for 10,000 / 20,000 hour intervals, and lifetime technical consultation on application retrofits.
10. Engineering Field Notes — Case Studies
11. Frequently Asked Questions
12. Partner with Ever Power
Ready to replace your 321L2 unit? Ever Power welcomes long-term distribution agreements, OEM private-label programs, MRO stocking contracts, and project-based bulk orders. Whether you are a maintenance team facing an urgent breakdown, a system integrator specifying new equipment, or a distributor expanding the gearbox portfolio, our engineering and sales teams are ready to support your project from specification to commissioning.
Send the original nameplate photo, duty sheet, and target delivery date to our team through the contact page. Let us help you secure plant uptime with a verified EP321L2 solution.
