The SF97 worm gear reducer is the large-frame member of the SF series offered by WGT. Designed around a 97 mm centre distance, it delivers the high reduction of a worm drive while the upstream helical stage recovers much of the efficiency a plain worm gearbox would lose. Plants use it where quiet, high-ratio right-angle drives must run for years with minimal attention - think thickeners, large agitators and quarry conveyors.
Overview
Built to the standard interface dimensions of the S97 frame family, the SF97 keeps your existing couplings, guards and foundations untouched. Output options include a solid shaft with key, or a hollow shaft with shrink disc for torque-locked mounting.
Data Sheet
| 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~ 68dB |
| Temp. rise (max) | 40°C |
| Temp. rise (oil) (max) | 5 0°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 |
Typical duty points where this unit is specified:
- Agriculture and food processing
- Chemical and environmental protection plants
- Wood, forest and recycling equipment
- Conveyors, mixers, agitators and hoists
- Metal processing lines
Purchase Information
WGT supplies the SF97 speed reducer factory-direct with transparent EXW pricing and full pre-shipment test records (noise, temperature rise, backlash). Standard lead time is 5-10 weeks; urgent orders can be prioritised. Every unit is guaranteed for one year, with seal and bearing spares available from stock. Share your ratio, torque and mounting data for a same-day quotation and drawing package.
Application Cases
Flour mill screw conveyors
A flour mill standardised on SF57 gear reducers for its screw conveyor network. One spare-part pool now covers fifteen drives, and the smooth helical input stage keeps noise low in the packing hall.
Warehouse vertical lift
A logistics integrator selected SA67 units for pallet lifts. The hollow output bore carries the lift screw directly, and one year of three-shift operation has passed without a single seal replacement.
![industrial gearbox applications - conveyor mixer crusher wastewater]()
Selection Example: 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, i=96 one-stage-worm territory but with the helical stage saving efficiency. In this case foot mounting and M1-M6 positions fit the clarifier bridge layout. The same three numbers - motor speed, target output speed, required torque - are all you need; our engineers (or the online selector below) cross-check the service factor for your duty cycle.
![how to size a gear reducer in 4 steps - gearbox selection flow]()
Common Models in the SF Series
| Model | Centre distance | Output | Typical duty |
|---|
| SF37 | 37 mm | solid shaft, foot | small conveyors, dosing |
| SF47 | 47 mm | solid shaft, foot | packaging, dosing pumps |
| SF57 | 57 mm | solid shaft, foot | belt conveyors, stirrers |
| SF67 | 67 mm | solid shaft, foot | mixers, feeders |
| SF77 | 77 mm | solid shaft, foot | turntables, elevators |
| SF87 | 87 mm | solid shaft, foot | screw conveyors, washers |
| SF97 | 97 mm | solid shaft, foot | thickeners, kilns |
| SF107 | 107 mm | solid shaft, foot | heavy material handling |
The table below lists the eight foot-mounted frames;
Naming makes selection easy: S = solid shaft, SA = hollow shaft, SAF = hollow shaft with flange, SAZ = torque-arm version - all sharing the same gear set and centre distance as the SF foot model.
Get Your Drawing and Quotation within 24 Hours
Ready to size your drive? Not sure which model fits? Try our online WGT Motor & Gearbox Online Selection System to match motor power, ratio and mounting in one minute.
Or simply send your motor data (kW, speed, duty) and driven-machine details through the inquiry button - we reply with a completed datasheet, dimension drawing and factory price the same working day. Looking for a gearbox for crusher? Tell us the duty point and we will confirm the model in writing.
Frequently Asked Questions
How efficient is a helical worm gear reducer?
The two-stage design reaches 94%~96% efficiency depending on the transmission stage - well above a single-stage worm unit, because the helical input stage handles the first reduction with less sliding loss.
Which lubricating oil should be used?
GB L-CKC220~460 or Shell Omala 220~460 as supplied. Under normal duty the housing is lubricated for life; in hot or continuous-duty environments an oil change after the first 400 hours and then every 4000 hours is recommended.
