311 Series Inline Planetary Gearbox
Trusted Across Industries:
Industrial Conveyor & Hoist
Port Crane & Lifting Equipment
Cement & Aggregates Plant
Marine & Offshore
Construction Machinery
Paper & Steel Mill
Oil & Gas Processing
Why Choose Our 311 Series Inline Planetary Gearbox? — Our 311 Series is dimensionally verified against Bonfiglioli 311 Series OEM installation drawings — covering all standard configurations: 311L1, 311L2, 311L3, 311L4 (inline, 1 to 4 stages) and 311R2, 311R3, 311R4 (right-angle with bevel input). Housing bolt pattern, output shaft diameter and keyway, motor flange pilot diameter, and oil fill/drain/level plug positions are all confirmed to OEM dimensions before a cross-reference is issued. T2max 55 000 N·m. Gear ratios 3.4:1 to 9,000:1. Transmissible power up to 450 kW. Profile-ground gear sets throughout. Integrated hydraulic, DC, and AC brake options. Free 48-hour cross-reference — just send us the nameplate data.
311 Series Inline Planetary Gearbox — Product Overview
The 311 Series Inline Planetary Gearbox occupies the mid-to-upper range of the Bonfiglioli 300 Series torque family — frame size 311 sits between the 310 and 313, with a published T2max of 490,000 in·lbs (approximately 55,000 N·m) in the Bonfiglioli 300 Series specification. This makes the Bonfiglioli 311 one of the most widely specified inline planetary gearboxes in heavy conveyor, hoist, crane travel, and process plant applications worldwide — and consequently, one of the most frequently requested replacement models in our aftermarket supply programme.
Our 311 Series Inline Planetary Gearbox is a confirmed dimensional replacement for all Bonfiglioli 311 model variants: 311L1 / 311L2 / 311L3 / 311L4 (inline, 1 through 4 reduction stages) and 311R2 / 311R3 / 311R4 (right-angle with spiral bevel first stage, 2 through 4 stages). Every critical dimension is matched to the original — housing bolt pattern, output shaft interface, motor flange pilot diameter, and mounting foot dimensions. The 311 Series inherits the full modular configuration range of the Bonfiglioli 300 platform: five output shaft types, four input interface options, and three integrated brake variants — enabling a direct bolt-in replacement without any modification to the existing machine structure.
Transmissible power is up to 450 kW with gear ratios spanning 3.4:1 to 9,000:1 across 1 to 4 inline stages or 2 to 4 right-angle stages. All gears are carburised, hardened to 58–62 HRC, and profile-ground to DIN/ISO Class 6. ISO 9001:2015 certified production. 100% factory acceptance test at rated torque and speed before shipment. Common ratio configurations stocked in partial-build for 7–20-day delivery.
311 Series OEM Cross-Reference — All Model Variants & Equivalent Brands
Our 311 Series Inline Planetary Gearbox provides confirmed dimensional replacement for the following OEM models. All housing interfaces, output shaft geometry, torque ratings, and motor flange standards are verified against OEM installation drawings before a cross-reference is confirmed.
① Bonfiglioli (Trasmital) — 311 Series: All Model Numbers
The Bonfiglioli 311 is the primary OEM model our 311 Series is engineered to replace. The table below covers every standard ordering variant — inline (L) and right-angle (R) versions, single through four-stage reductions, and all standard output shaft suffix codes.
| Bonfiglioli Model | Version | Stages | T2max | Our Equivalent |
|---|---|---|---|---|
| 311L1 | Inline, 1-stage | 1 | ~55,000 N·m | 311-L1 |
| 311L2 | Inline, 2-stage | 2 | ~55,000 N·m | 311-L2 |
| 311L3 | Inline, 3-stage | 3 | ~55,000 N·m | 311-L3 |
| 311L4 | Inline, 4-stage | 4 | ~55,000 N·m | 311-L4 |
| 311R2 | Right-angle, 2-stage | 2 (bevel + planetary) | ~55,000 N·m | 311-R2 |
| 311R3 | Right-angle, 3-stage | 3 (bevel + 2 planetary) | ~55,000 N·m | 311-R3 |
| 311R4 | Right-angle, 4-stage | 4 (bevel + 3 planetary) | ~55,000 N·m | 311-R4 |
Standard Output Shaft Suffix Codes — All 311 Variants
| Bonfiglioli Suffix | Output Shaft Type | Mounting | Available in Our 311 Series |
|---|---|---|---|
| NHC / HC | Heavy-duty flanged output — keyed shaft | Flange | ✓ Yes |
| NHZ / HZ | Heavy-duty splined male shaft | Flange | ✓ Yes |
| NPC / PC | Foot base — keyed shaft | Foot | ✓ Yes |
| FZ / FZB | Hollow splined shaft | Flange | ✓ Yes |
| FP | Hollow shaft for shrink disc | Flange | ✓ Yes |
311 Series in Context — Bonfiglioli 300 Series Frame Size Ladder: The 311 is frame size 18 of 20 in the Bonfiglioli 300 Series range (310 → 311 → 313). The adjacent sizes — 310 (T2max ~40,000 N·m) and 313 (T2max ~65,500 N·m) — are also available from our range as the 310 Series and 313 Series respectively. If a dimensional cross-reference confirms the existing machine uses a 310 or 313 rather than a 311, we supply the correct series as a confirmed replacement. Contact us with the full model number including frame size and we confirm the right replacement unit within 48 hours.
② Brevini Riduttori (Dana) — Equivalent Models in the Same Torque Class
The Brevini ED and ET series inline planetary gearboxes overlap with the Bonfiglioli 311 torque class at approximately 50,000–70,000 N·m continuous rated torque. The following Brevini models are dimensionally cross-referenced and confirmed as equivalent to our 311 Series:
| Brevini Model | Series | Rated Torque | Stages | Typical Application |
|---|---|---|---|---|
| ED2250 / ED2255 | ED Series | ~50,000 N·m | 2 stage | Industrial conveyor, winch |
| ED2320 | ED Series | ~65,000 N·m | 2 stage | Mining conveyor, crane drive |
| ET3250 / ET3255 | ET Series | ~50,000 N·m | 3 stage | Hoist, drum winch |
| ET3320 | ET Series | ~65,000 N·m | 3 stage | Heavy industrial plant, port crane |
| EQ4250 / EQ4255 | EQ Series | ~50,000 N·m | 4 stage | Conveyor, agitator drive |
| EC3250 / EC4250 | EC Series | ~50,000 N·m | 3–4 stage | Conveyor with integrated brake |
③ Dinamic Oil — RE / GB Series (50,000–70,000 N·m Class)
Dinamic Oil's RE and GB series inline planetary gearboxes in the 50,000–70,000 N·m torque class are interchangeable with the 311 Series through confirmed dimensional cross-reference:
| Dinamic Oil Model | Rated Torque (N·m) | Typical Application |
|---|---|---|
| RE4800 | ~48,000 | Industrial hoist, crane travel drive |
| RE6000 | ~60,000 | Mining conveyor, cement plant drive |
| RE8000 | ~80,000 | Large crane drum, heavy hoist |
④ Reggiana Riduttori — RR / RA Series (50,000–70,000 N·m Class)
Reggiana Riduttori's RR and RA inline planetary series in the equivalent torque band are cross-referenced as follows:
| Reggiana Series | Torque Class (N·m) | Configuration | Typical Application |
|---|---|---|---|
| RR Series (50K–70K class) | 50,000 – 70,000 | Coaxial, 2–4 stages | Industrial conveyor, rotary table |
| RA Series (50K–70K class) | 50,000 – 70,000 | Coaxial, 2–4 stages | Marine, heavy industrial plant |
⑤ Additional OEM Cross-References — Same Torque Class
Beyond the four primary brand families above, the 311 Series covers the following OEM inline planetary models in the 50,000–70,000 N·m torque range. Submit the model number for confirmation within 48 hours:
| OEM Brand | Series / Models | Torque Class | Notes |
|---|---|---|---|
| Bosch Rexroth | GFT50 / GFT60 / GFT80 Inline | 50,000 – 80,000 N·m | Hydraulic motor input, inline planetary |
| Rossi | MR3E / MR4E (50K–70K class) | 50,000 – 70,000 N·m | Italian industrial plant, conveyor |
| Zollern | ZHP3.24 / ZHP3.25 | ~50,000 – 65,000 N·m | Crane, heavy industrial |
| Antriebstechnik O&K | F / FA Series (50K–70K class) | 50,000 – 70,000 N·m | Construction and industrial drive |
| Fairfield Manufacturing | W Series (50K–70K class) | 50,000 – 70,000 N·m | Industrial and marine hoist |
Free 48-Hour Cross-Reference Service: Send us the OEM brand, model number (e.g., Bonfiglioli 311L2 NHC, Brevini ED2320, or Dinamic Oil RE6000), ratio, and motor flange type from the nameplate of the gearbox you need to replace. Our engineering team will confirm the 311 Series equivalent with a dimensional drawing and delivery timeline within 48 hours — at no charge.
311 Series Inline Planetary Gearbox — Technical Specifications
Standard engineering parameters for the 311 Series, aligned with the Bonfiglioli 311 and equivalent OEM specifications. All parameters match or exceed the original OEM ratings.
| Parameter | Specification | Notes |
|---|---|---|
| T2max (Peak Torque) | ~55,000 N·m (490,000 in·lbs) | Matches Bonfiglioli 311 T2max specification |
| Transmissible Power | Up to 450 kW | Matches Bonfiglioli 300 Series power ceiling |
| Gear Ratio Range | 3.4:1 – 9,000:1 | 1 to 4 inline stages; right-angle versions 2–4 stages |
| Gear Unit Versions | Inline (L) / Right-angle (R) with spiral bevel first stage | Matching Bonfiglioli 311L and 311R configurations |
| Output Configurations | Foot & flange mounted; solid keyed shaft; splined shaft; hollow splined; hollow with shrink disc | All Bonfiglioli 311 suffix codes reproduced |
| Input Configurations | Flanged axial-piston motor / Orbit motor / IEC B5 adaptor / NEMA adaptor / Solid input shaft | Custom adaptor plates for non-standard motors |
| Brake Options | Hydraulic-released parking brake / DC electric brake / AC electric brake | All Bonfiglioli 311 brake variants available |
| Transmission Efficiency | 96% – 98% per stage | Rolling-contact planetary; consistent with OEM specification |
| Gear Material | 20CrMnTi / 18CrNiMo7-6 Alloy Steel | Carburised, 58–62 HRC; profile-ground DIN/ISO Class 6 |
| Housing Material | Ductile Iron GGG-50 | Machined to Bonfiglioli 311 reference dimensions |
| Sealing / IP Rating | IP65 standard / IP67 optional | Double-lip radial shaft seals; cassette seals for harsh environments |
| Lubrication | Mineral or Synthetic ISO VG 220/320 gear oil | Vent plug, level plug, and drain plug positions match OEM |
| Operating Temperature | -30°C to +100°C | Extended range options available |
| Surface Treatment | Epoxy primer + two-component PU topcoat | Salt spray >500 hours ISO 9227 |
| Design Life (B10) | 3,000+ hours at rated load | Per ISO 281 and AGMA 2001 standards |
| Certification | ISO 9001:2015, CE Declaration of Conformity | FAT report supplied with every unit |
| Lead Time | 7 – 20 days (standard) / 30 – 60 days (custom ratio) | Common 311L2 / 311L3 replacement ratios in partial-build stock |
Core Advantages
Eight reasons engineers and plant managers specify our 311 Series as their Bonfiglioli 311 replacement:
● Verified Dimensional Match
Every 311 Series cross-reference is verified against Bonfiglioli 311 installation drawings — housing bolt pattern, output shaft diameter and keyway, motor flange pilot diameter — before confirmation. No assumptions from published torque data alone.
● All 7 Bonfiglioli 311 Variants Covered
311L1, 311L2, 311L3, 311L4 (inline) and 311R2, 311R3, 311R4 (right-angle) — all standard reduction stage counts and all output shaft suffix types are covered by confirmed replacement models in our production range.
● T2max 55,000 N·m — Matched to OEM
The 311 Series is rated to match the Bonfiglioli 311 T2max of ~55,000 N·m (490,000 in·lbs) — ensuring the replacement unit meets the same maximum peak torque capability as the original without upsizing to the 313 frame or downsizing to the 310 frame.
● Profile-Ground Gear Sets
All sun gears, planet gears, and ring gears are carburised, hardened to 58–62 HRC, and profile-ground to DIN/ISO Class 6 — the same quality level as specified in the Bonfiglioli 300 Series production standard. Not substituted with lower-accuracy hobbed gears to reduce cost.
● 96–98% Per-Stage Efficiency
Rolling-contact planetary gearing delivers 96–98% efficiency per stage — consistent with the original Bonfiglioli 311 specification. In continuous-duty applications (conveyors, hoists, pumps) running thousands of hours per year, this efficiency level directly reduces operating energy cost compared with worm-gear alternatives.
● Full Brake Integration
Hydraulically-released parking brake, DC electric brake, and AC electric brake are available as factory-integrated options — matching all Bonfiglioli 311 brake configurations. Brake torque is rated to hold the full nominal output torque at any gear ratio in the range. Essential for hoist, crane, and inclined conveyor applications.
● Short Lead Times from Stock
The 311L2 and 311L3 in the most common gear ratios (typically 25:1 to 400:1) are held in partial-build stock — machined housing and completed gear sets — allowing final assembly and factory acceptance test completion within 7–20 days. Faster than OEM Bonfiglioli lead times for replacement units.
● 100% Factory Acceptance Test
Every unit is run at rated torque and speed for a minimum of two hours on our loaded test benches. Oil temperature, housing surface temperature, vibration, and seal integrity are all measured and reported. A complete test report is supplied with every shipment.
How the 311 Series Inline Planetary Gearbox Works
The 311 Series uses the same coaxial multi-stage planetary gear architecture as the Bonfiglioli 311 it replaces. The five steps below describe the complete power flow:
Motor Input
The electric or hydraulic motor drives the first-stage sun gear at rated input speed. The input flange matches the motor standard exactly — IEC, SAE, or NEMA — eliminating adaptor plates in direct replacement installations.
Planet Gear Load Sharing
Three or more planet gears engage simultaneously between the sun gear and the fixed ring gear. Each planet carries a proportional share of total torque — the fundamental mechanism enabling the 311 Series' 55,000 N·m peak torque capacity in a compact housing.
First-Stage Reduction
The planet carrier outputs at reduced speed and multiplied torque. Speed and torque change in direct proportion to the first-stage ratio. The coaxial output direction is maintained — input and output remain on the same centreline.
Additional Stages
For the high ratios required in conveyor and hoist applications — 100:1 to 9,000:1 — the 311 Series adds two, three, or four reduction stages. Each additional stage multiplies output torque while adding only modest axial length to the housing.
Coaxial Output
The final-stage carrier drives the output shaft or flange at rated torque and low speed — fully coaxial with the motor input and through exactly the same output interface geometry as the Bonfiglioli 311 it replaces.
311 Series Application Scenarios
The Bonfiglioli 311 is predominantly specified in high-torque industrial drives. Our 311 Series covers the same application sectors with confirmed dimensional and performance equivalence:
Mining & Bulk Material Conveyor Drives
The Bonfiglioli 311L2 and 311L3 are among the most common drives in long-distance mining belt conveyors, bucket elevators, and reversing conveyor systems. The 311 Series' T2max of 55,000 N·m covers the rated continuous torque of typical 250–350 kW conveyor tail and head pulley drives at ratios of 50:1 to 200:1.
Industrial Hoist & Overhead Crane
Overhead crane hoist units, maintenance hoists, and industrial winches in the 200–450 kW power class. The 311 Series with integrated brake option meets the load-holding requirements of EN 14492-2 (crane hoist standard). The 311R2 and 311R3 right-angle variants are common in crane drives where the motor axis must be perpendicular to the drum axis.
Cement, Aggregates & Quarry Plant
Drum mixer drives, rotary kiln auxiliary drives, and quarry conveyor drives in cement and aggregates processing. The 311 Series is designed for continuous-duty shock-load applications — its carburised and ground planetary gear sets and heavy-capacity output shaft bearings match the shock-load resistance demanded by cement plant operation.
Port & Container Crane Travel Drives
Long-travel drive units on rubber-tyred gantry (RTG) cranes, rail-mounted gantry (RMG) cranes, and ship-to-shore (STS) cranes. The 311 Series' wide ratio range (to 9,000:1) and compatibility with orbital hydraulic motors make it the standard specification for crane travel drives in ports where Bonfiglioli 311 units are the existing equipment.
Marine & Offshore Deck Equipment
Deck crane auxiliary winch drives, mooring capstan drives, and deck machinery ancillary drives on vessels and offshore platforms. The 311 Series IP67 option and marine coating system (ISO 12944 C5-M) make it suitable for exposed marine environments. BV and ABS certification available on request.
Construction Machinery Auxiliary Drives
Concrete pump truck gearboxes, drilling rig auxiliary drives, and piling machine drives. The 311 Series with hydraulic orbit motor input is a standard replacement specification for Bonfiglioli 311 units in these applications, providing the same operating torque in a confirmed bolt-in package.
311 Series — Frequently Asked Questions
Common questions from maintenance engineers and procurement teams sourcing Bonfiglioli 311 replacements:
Q 01
Is the 311 Series a confirmed bolt-on replacement for the Bonfiglioli 311L2 and 311L3?
Yes. Our 311 Series models are dimensionally verified against Bonfiglioli 311 Series OEM installation drawings — covering all standard configurations from 311L1 through 311L4 and 311R2 through 311R4. Housing bolt pattern, output shaft diameter and keyway dimensions, and motor flange pilot diameter are all confirmed before a cross-reference is issued. Send us the complete Bonfiglioli model number including the reduction stage suffix (L1 through L4) and output shaft suffix (e.g., NHC, FP, NPC) and we return a confirmed dimensional match within 48 hours.
Q 02
What is the T2max of the Bonfiglioli 311 Series and how does the 311 Series replacement compare?
The Bonfiglioli 311 Series has a published T2max of 490,000 in·lbs, which converts to approximately 55,367 N·m. Our 311 Series replacement is designed and rated to the same T2max — meaning it can withstand the same static and peak torque as the original unit without exceeding its structural limits. This is the critical parameter for hoist and crane applications where momentary peak loads must not exceed the gearbox's maximum rated torque.
Q 03
My Bonfiglioli 311L3 has an FP (hollow shaft for shrink disc) output — do you stock this configuration?
Yes. The hollow shaft with shrink disc (Bonfiglioli suffix FP) is one of the five standard output configurations available on the 311 Series and is among the most frequently ordered replacements — particularly for conveyor drum drives where the shrink disc eliminates the need for a rigid shaft coupling. Specify the shrink disc bore diameter and torque rating when ordering; we will confirm the matching output shaft configuration from our standard range or manufacture a custom bore if required.
Q 04
Can the 311 Series replace Brevini ED2320 and ET3320 in the same torque class?
Yes, with confirmed dimensional cross-reference. The Brevini ED2320 and ET3320 inline planetary models are in the same torque class as the Bonfiglioli 311 — approximately 60,000–70,000 N·m — and our 311 Series cross-reference database covers these models. Provide the Brevini model number (including the ratio code) and we return a dimensional comparison with our 311 Series equivalent and confirm whether the housing interfaces are directly interchangeable or require an adaptor plate for the motor flange standard.
Q 05
What gear ratio options are available in the 311 Series and how do they correspond to Bonfiglioli 311 standard ratios?
The 311 Series covers the full ratio range of 3.4:1 to 9,000:1 with the same stage configurations as the Bonfiglioli 311 — single stage (L1) for ratios up to approximately 10:1, two-stage (L2) for 10:1 to 100:1, three-stage (L3) for 100:1 to 1,500:1, and four-stage (L4) for 1,500:1 to 9,000:1. The Bonfiglioli 300 Series ratio tables list specific available ratios for each stage configuration — if your existing unit has a specific ratio from the Bonfiglioli catalogue, provide that ratio code and we confirm the exact matching 311 Series specification. For ratios outside the standard tables, custom configurations are available with 30–60-day lead times.
Q 06
How does the 311 Series relate to the Bonfiglioli 310 and 313 in the frame size ladder?
In the Bonfiglioli 300 Series, the 311 is flanked by the 310 (T2max ~40,000 N·m) and the 313 (T2max ~65,500 N·m). If the existing machine was specified with a 310 or 313 rather than a 311, we supply the correct frame size from our parallel 310 Series or 313 Series replacement range — not a 311 that would be either under-rated or physically too large. Always confirm the exact frame size number from the nameplate before ordering; the three model numbers are often confused in the field because the housing dimensions are similar.
Q 07
What documentation is supplied with each 311 Series replacement unit?
Every unit is supplied with: (1) full factory acceptance test report — run at rated torque and speed for minimum 2 hours, recording oil temperature, housing surface temperature, vibration, and seal integrity; (2) EN 10204 3.1 material certificates for all alloy steel forgings; (3) heat treatment batch records; (4) gear tooth profile and lead measurement records; (5) CE Declaration of Conformity; (6) installation and maintenance manual. All documentation is supplied in English as standard.
Quality Assurance
- ✓ ISO 9001:2015 Certified Production — all processes from raw material inspection to final assembly and test controlled under our certified QMS.
- ✓ 100% Loaded Factory Acceptance Test — every unit run at rated torque and speed for minimum 2 hours; full test report supplied with every shipment.
- ✓ Profile-Ground Gear Inspection — gear tooth profile and lead measurement records supplied with every unit.
- ✓ EN 10204 3.1 Material Certificates — alloy steel forgings with mill certificates; heat treatment records maintained 10 years.
- ✓ Verified Dimensional Cross-Reference — all OEM replacement cross-references verified against Bonfiglioli 311 installation drawings before confirmation to the customer.
- ✓ CE Declaration of Conformity — supplied with all units; BV, ABS, and Lloyd's certification available for marine and offshore projects.
How to Order a 311 Series Replacement
Read the Nameplate
Record OEM brand, series, full model number (e.g., 311L3 NHC or 311R2 FP), gear ratio, and motor flange code from the gearbox nameplate or maintenance manual.
Submit Cross-Reference
Send nameplate data to our engineering team. We verify dimensional match against Bonfiglioli 311 OEM drawings and confirm the 311 Series equivalent within 48 hours.
Confirm Options
Specify brake type (hydraulic/DC/AC/none), output shaft type, input motor flange (IEC / SAE / NEMA), and IP rating (IP65 or IP67).
Receive Quotation
Firm quotation with lead time, dimensional drawing for installation check, and CE documentation reference supplied within 48 hours of confirmed cross-reference.
Tested & Shipped
Every unit fully assembled and FAT-tested at rated torque before shipment. Test report, material certificates, and CE documentation included in delivery package.
Related Products — Compatible Drive Components
Compatible Motors for the 311 Series
The 311 Series is engineered for direct motor attachment across all standard IEC, SAE, and NEMA input flanges — no coupling adaptor required for the most common motor configurations. Our matched motor range covers the complete input power and speed envelope of the 311 Series, from high-frame IEC electric motors for industrial conveyor, hoist, and crane drives to high-displacement hydraulic axial-piston motors for mining, port machinery, and marine applications — all factory-paired and fully loaded-tested as a complete drive assembly before shipment.
Frame 132 to 450, IE3 / IE4 efficiency class, 7.5 kW to 450 kW — direct IEC B5 flange mount to all 311 Series inline inputs. Optional integrated DC or AC electromagnetic brake for full static load holding on hoist, crane, and inclined conveyor drives where EN 14492-2 compliance is required.
SAE C / D flange — displacement 75 to 500 cc/rev, continuous pressure 350–450 bar. The primary motor type for the 311 Series in mining conveyor, port crane, marine deck equipment, and heavy hoist applications requiring the full 55,000 N·m output torque envelope at demanding duty cycles.
SAE B / C flange — compact and reliable for construction machinery, crane travel, and light-duty applications in the 311 Series torque range. Direct SAE flange mount to the 311 Series input with no adaptor plate required for standard orbit motor configurations.
Ready to Replace Your Bonfiglioli 311 or Equivalent Gearbox?
Whether you need a confirmed 311L1, 311L2, 311L3, or 311L4 replacement — right-angle 311R2, 311R3, or 311R4 — or an equivalent for a Brevini ED / ET, Dinamic Oil RE, or other brand model in the same torque class, our engineering team will confirm the 311 Series model, issue a dimensional drawing, and provide a firm quotation within 48 hours.
