The SA67 worm gear reducer pairs a hollow output bore with the 67 mm helical-worm gear set of the SF family, matching the standard mechanical interface of the SA67 frame family. Maintenance teams like it because retrofitting takes minutes: slide the unit onto the existing shaft, fix the torque arm, connect the motor - and the line runs again.
Product Description
Inside the cast-iron housing (HBS190-240) a helical pinion takes motor speed down to the worm stage, which finishes the reduction at 94%~96% overall efficiency. Gears are ground to grade 6~5, so the drive stays at 60~68 dB even after years of service. Backlash is held within 20 arcmin.
Specifications
| 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 |
Where customers install this series:
- Conveyors, mixers, agitators and hoists
- Building and construction machinery
- Textile, leather and paper industry
- Chemical and environmental protection plants
- Car-washing and car-park systems
Quotation & Delivery
WGT quotes the SA67 gear reducer factory-direct - the price you see is the works price, packed and documented for export. Standard build ships in 5-10 weeks from NINGBO / SHANGHAI; popular ratios often ship sooner. Each unit carries a one-year warranty, and our engineers assist with selection, oil specification and spare-part planning at no extra cost.
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.
Selection Example: Kneader machine
Take a 4 kW, 1440 rpm motor kneading dough arms at 48 rpm. The ratio follows directly: 1440 / 48 = 30, i=30. In this case the hollow shaft and torque arm wash down easily in food areas. 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]()
Application Cases
Rotary indexing table
A machine builder drives a two-metre indexing table with an SF77 reducer. Backlash within 20 arcmin keeps positioning repeatable, which mattered more to the customer than the price difference to a plain worm unit.
Sawmill crushing line
A wood-processing plant drives its crusher with an SF97 unit. The cast-iron housing (HBS190-240) resists impact, and the high-torque worm stage starts the crusher under load without a soft-starter.
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.
![industrial gearbox applications - conveyor mixer crusher wastewater]()
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 gear motor for car wash system? Tell us the duty point and we will confirm the model in writing.
