The S97 large worm gear reducer is the largest frame in the WGT S range. Built around a 97 mm centre distance, it delivers high torque at very low output speed while its helical input stage keeps efficiency high - exactly what thickeners, large agitators, screw presses and heavy conveyors need, and where a pure worm unit would simply overheat at the ratio required.
Large Frame, High Reduction
- Precision-machined cast-iron or ductile-iron housing, HBS190-240, single-setup boring for alignment
- 20CrMnTi gears carburised to HRC58~62; 42CrMo shafts quenched and tempered to HRC25~30
- Noise 60~68 dB; vibration 20 μm or less; backlash 20 arcmin or less
- Lubrication GB L-CKC220~460 or Shell Omala 220~460; NAK oil seals standard
- Mounting: foot, flange or shaft; M1-M6 positions; two- and three-stage builds
S97 Technical Data
| Housing material | Cast iron/Ductile iron |
| Housing hardness | HBS190-240 |
| Gear material | 20CrMnTi alloy steel |
| Surface hardness of gears | HRC58~62 |
| Gear core hardness | HRC33~40 |
| Input / Output shaft material | 42CrMo alloy steel |
| Input / Output shaft hardness | HRC25~30 |
| Machining precision of gears | precision grinding, grade 6~5 (ISO 1328) |
| Lubricating oil | GB L-CKC220~460 / Shell Omala 220~460 |
| Heat treatment | tempering, cementit-ing, quenching, etc. |
| Efficiency | 94%~96% (depends on the transmission stage) |
| Noise (max) | 60~68 dB |
| Temp. rise (max) | 40 C |
| Temp. rise (oil) (max) | 50 C |
| Vibration | ≤20μm |
| Backlash | ≤20Arcmin |
| Brand of bearings | HRB/LYC/ZWZ/C&U (SKF, FAG, INA, NSK optional) |
| Brand of oil seal | NAK -- Taiwan or other brands requested |
Industries that buy this model most often:
- Chemical and environmental plants
- Wastewater treatment and water supply
- Building and construction machinery
- Metal processing and forming lines
- Textile, leather and paper industry
Purchase Information
WGT supplies the S97 factory-direct with transparent EXW pricing and full pre-shipment test records. Standard lead time is 5-10 weeks and urgent orders can be prioritised. interface dimensions matching the S97 frame family keep existing couplings and foundations in place. Share your ratio, torque and mounting data for a same-day quotation and drawing package.
Available Frames and Their Typical Duty
| Model | Centre distance | Output | Typical duty |
|---|
| S97 | 97 mm | solid shaft, foot | thickeners, heavy conveyors |
| S37 | 37 mm | solid shaft, foot | dosing screws, small conveyors |
| S47 | 47 mm | solid shaft, foot | packaging, small mixers |
| S57 | 57 mm | solid shaft, foot | bagging belts, stirrers |
| S67 | 67 mm | solid shaft, foot | paddle mixers, feeders |
| S77 | 77 mm | solid shaft, foot | turntables, elevators |
| S87 | 87 mm | solid shaft, foot | screw conveyors, washers |
Note that S and SF model numbers of the same frame are fully interchangeable in terms of gearing; only the output interface and mounting differ. That keeps your stock of spare internals small.
Questions and Answers
What is the difference between a keyed hollow shaft and a shrink-disc connection?
A keyed hollow shaft is the economical choice for normal torque and easy maintenance. A shrink-disc connection transmits higher torque with zero backlash and no keyway wear, and is preferred for reversing or high-torque duties.
Can I get a CAD drawing or 3D model for my design review?
Yes. Send us the model and ratio and we provide a 2D dimension drawing and a 3D STEP model for your review, usually the same working day. Drawings follow the layout of the original series so they drop into your existing assembly.
What is the recommended oil change interval?
The housing is lubricated for life under normal duty and normal ambient. In hot, humid or continuous service, change the oil after the first 400 running hours and then every 4000 hours, or once a year, whichever comes first.
Installation Examples
Sugar mill cane carrier
A sugar mill selected SF107 helical-worm units for its cane carrier. The high starting torque of a fully loaded carrier is covered by the generous service factor, and the right-angle layout fits the confined mill floor.
Paper mill pulp agitator
A paper mill uses SF87 reducers on pulp chest agitators. Continuous 24-hour duty is handled by lifetime lubrication, and the low backlash keeps the agitator steady when the stock consistency changes.
![gear box application map for industry]()
From quarries to food plants - one right-angle drive concept.
Selection Example: Wastewater thickener rake
Take an 11 kW motor at 960 rpm turning a thickener rake at under 10 rpm. The ratio follows directly: 960 / 10 = 96 - right in helical-worm territory. In this case foot mounting and M1-M6 positions fit the clarifier bridge layout. The ratio is the easy part. The service factor for the shock level is what makes the selection safe, and we check that for you at no charge.
![how to choose a speed reducer model]()
Ratio first, then torque, then frame size: the standard selection route.
Design Review, Datasheet and Price - Same Day
Planning a new machine? The WGT Motor & Gearbox Online Selection System covers motor power, ratio and mounting on one screen - enter your numbers and see the model immediately.
Send the interface drawing or the frame dimensions you need to match, and we return a 2D drawing and 3D STEP model with the quotation, so your design review is not held up waiting on the supplier. Looking for a gearbox for crusher? Tell us the duty point and we will confirm the model in writing.
