Supply capacity: 600 sets/month Delivery time: 5-10 weeks Packing: Standard export wooden crate Port: NINGBO / SHANGHAI PORT Warranty: one year
The SA37 hollow shaft gear reducer replaces a coupling with a bore. Instead of bolting a solid shaft to the driven machine, the SA37 slides straight onto the machine shaft and is locked with a key or a shrink disc - one less alignment problem, one less guard to buy. Behind that bore sits the familiar WGT helical-worm gear set, so a 37 mm frame still reaches high ratios at 90 degrees.
| 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 |
Main fields of application:
Tell us the driven shaft diameter, the ratio you need and the reaction you can support, and WGT returns a dimension drawing plus a firm price. If you are replacing a unit that is already on the machine, a photo of the nameplate is usually enough for us to identify the frame. Every SA37 gear reducer ships in an export wooden crate with a one-year warranty.
Take a 1.1 kW four-pole motor (1400 rpm) turning an agitator at 47 rpm. The ratio follows directly: 1400 / 47 = 29.8, so i=30 is selected. In this case the hollow output drops straight onto the agitator shaft - no coupling, no pedestal. 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.

Figure: from motor data to a confirmed gearbox model in four steps.
| 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.
A municipal wastewater plant replaced twelve ageing agitator drives with SA-series helical worm units. Sealed housings and NAK oil seals stood up to the humid atmosphere, and the hollow-shaft mounting let the maintenance crew swap units without touching the mixer shafts.
A stone quarry runs SF87 reducers on its primary conveyor. Shock loads from oversized rock are absorbed by the case-hardened gears (surface HRC58-62), and after two years of continuous duty the units still run within their original 68 dB noise spec.

Figure: typical industries that use the WGT S-series gear reducers.
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.
They share one gear set: SF is foot-mounted with solid shaft, S is shaft-mounted, SA has a hollow output shaft, SAF adds a flange, and SAZ is the torque-arm version. Pick by mounting, not by performance.
Yes - the series is manufactured to the same centre distances, shafts and flange dimensions of the common industry frames, so couplings, guards and foundations stay untouched.
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 belt conveyor? Tell us the duty point and we will confirm the model in writing.
Supply capacity: 600 sets/month Delivery time: 5-10 weeks Packing: Standard export wooden crate Port: NINGBO / SHANGHAI PORT Warranty: one year
Delivery time: 5-10 weeks Warranty: one year Supply capacity: 600 sets/month Port: NINGBO / SHANGHAI PORT Packing: Standard export wooden crate
Packing: Standard export wooden crate Port: NINGBO / SHANGHAI PORT Supply capacity: 600 sets/month Warranty: one year Delivery time: 5-10 weeks
Delivery time: 5-10 weeks Warranty: one year Supply capacity: 600 sets/month Port: NINGBO / SHANGHAI PORT Packing: Standard export wooden crate
Packing: Standard export wooden crate Port: NINGBO / SHANGHAI PORT Supply capacity: 600 sets/month Warranty: one year Delivery time: 5-10 weeks
Supply capacity: 600 sets/month Delivery time: 5-10 weeks Packing: Standard export wooden crate Port: NINGBO / SHANGHAI PORT Warranty: one year
Delivery time: 5-10 weeks Warranty: one year Supply capacity: 600 sets/month Port: NINGBO / SHANGHAI PORT Packing: Standard export wooden crate
Delivery time: 5-10 weeks Warranty: one year Supply capacity: 600 sets/month Port: NINGBO / SHANGHAI PORT Packing: Standard export wooden crate