When a heavy industrial application requires a planetary gearbox in the 30,000–500,000 Nm torque range, two series typically dominate the shortlist: the S series (replacing Brevini Riduttori S300–S7500) and the 311 series (replacing Bonfiglioli Trasmital 311L / 311R). Both are high-torque planetary gear units with overlapping torque ranges and similar applications. Choosing the wrong series adds cost or leads to a unit that cannot be certified for the project’s requirements. This guide compares them across six practical selection criteria — and identifies the specific conditions under which each series is the correct choice.
Overview: The Two Series at a Glance
The S series industrial planetary gearbox was originally developed by Brevini Riduttori as a high-density industrial and marine drive solution. Its design philosophy prioritises maximum torque in minimum volume — achieving 40–60% space and weight reduction compared to spiral gearboxes at equivalent torque ratings. The full range covers S300 through S20000 (13 frame sizes), with rated torques from 34,000 Nm to 2,170,000 Nm and DNV type approval as standard.
The 311 series planetary gearbox was developed by Bonfiglioli Trasmital as a modular industrial planetary for a broader range of applications — covering both inline (L) and right angle (R) configurations within the same housing, with ratio ranges up to 2,200:1 inline and 800:1 right angle. The 311 frame sits at 35,000 Nm rated torque and 180 kW rated power, within the broader 300–321 series range covering 1,000–1,100,000 Nm.
Both series sit in the same general torque class for the 311 vs S300/S400/S600 comparison. The key differences lie in certification requirements, output configuration flexibility, and application focus.
Side-by-Side Specification Comparison
| Parameter | S Series | 311 Series |
|---|---|---|
| Torque range (rated 10,000h) | 34,000 – 2,170,000 Nm | 1,000 – 450,000 Nm |
| Max rated power | Not power-limited (torque class) | Up to 450 kW |
| Output configuration | Inline (coaxial) only | Inline (L) + Right Angle (R) |
| Ratio range | Standard industrial ratios | 4 – 2,200:1 (L) · 18 – 800:1 (R) |
| DNV / Marine certification | ✓ DNV type approval + ABS PDA | Not standard (on request) |
| Integrated brake option | ✓ Negative multi-disc brake | ✓ Hydraulic + DC/AC brake |
| Space saving vs spiral | 40–60% | 30–45% |
| Primary application focus | Marine, mining, heavy industrial | Crane, winch, wheel & track drive |
Not sure which series fits your project?
View the Full Specification Pages for Both Series — Side by Side
Both product pages include complete torque tables, brake options, frame size drawings, and brand equivalents. For marine projects requiring DNV documentation, the S series page includes certification details.
Need a recommendation? Email [email protected] with your torque, ratio, and certification requirements — response within 24 hours.
Decision Guide: 5 Application Scenarios
Choose S series. DNV type approval and ABS PDA are standard on the S series. The certification documentation is issued with the unit, reducing the ship owner’s or shipyard’s documentation burden for the class survey. The 311 series can be supplied with certification on request, but it is not the series’ primary certification path.
Choose 311 series. The 311L inline and 311R right angle variants cover typical crane winch torque ranges with DC/AC brake options suitable for construction crane duty. The right angle (311R) output is often required for luffing winch geometry where the motor cannot be positioned coaxially with the drum.
Choose S series. The S series reaches 2,170,000 Nm rated torque at S20000 — torque levels that the 311 series (max ~450,000 Nm) does not cover. For mining applications, the S series’ 40–60% weight saving vs spiral alternatives also reduces the structural loads on mining equipment frames significantly.
Choose 311 series (ET / wheel drive configuration). The 311 series was specifically designed to cover wheel drive and track drive applications alongside crane and winch duty — using the same housing with different input/output configurations. The S series is designed for fixed industrial and marine mounting, not hub-mounted mobile equipment.
Match the brand: Brevini S series → our S series. Bonfiglioli 311L/311R → our 311 series. The dimensional equivalence is mapped within the same series. Cross-series replacement (using an S series unit to replace a 311 unit) requires dimensional verification before ordering even if the torque ratings overlap.
Overlap Zone: 35,000–150,000 Nm — How to Choose
In the 35,000–150,000 Nm range, both series have available frame sizes with overlapping ratings. The decision here comes down to three factors:
- Is DNV certification required? If yes → S series. If no → either series is viable.
- Is a right angle output needed? If yes → 311R series (S series is inline-only). If inline is fine → either series.
- Are you replacing an existing branded unit? If yes → match the original brand series as described above.
Related Searches
Secure Your Production Line Efficiency
For new machine designs where neither series has an existing installation, our engineering team can review your torque, ratio, certification, and mounting requirements and recommend the optimal series with supporting calculations. Send your requirements to [email protected]. View the full specifications for the S series industrial planetary gearbox and the 311 series planetary gearbox on their respective product pages — both include complete frame size torque tables and motor interface options.
Canada Planetarygeardrive Co.,Ltd
Sydney Office: 27 Harley Crescent Condell Park NSW 2200
Technical Support: [email protected]
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