The S37 helical worm gear reducer is the smallest foot-mounted unit of the WGT S range. A helical input stage takes motor speed down to an intermediate shaft, and a worm output stage finishes the reduction - so a single compact gearbox delivers high ratios without the efficiency penalty of a pure worm drive. Dimensionally it follows the common industry frame dimension, which means an existing baseplate, coupling and guard stay exactly where they are.
What the S37 Gives Your Machine
- Two-stage helical + worm transmission in one foot-mounted block
- Self-locking tendency on stop - useful where the load must not run back
- Rigid cast-iron housing at HBS190-240, bored in one setup for true alignment
- Case-hardened 20CrMnTi gearing, ground to grade 6~5, running at 60~68 dB
- Foot, flange or torque-arm mounting from one common gear set
S37 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 |
Main fields of application:
- Chemical and environmental plants
- Agriculture and food processing
- Car-washing and car-park systems
- Conveyors, mixers, agitators and hoists
- Building and construction machinery
Ordering the S37
Give us the ratio and output speed you need, or simply photograph the nameplate of the unit you are replacing. WGT checks the selection against your duty point and returns a firm quotation, a dimension drawing and a torque table - normally within one working day. Every S37 gear reducer carries a one-year warranty and ships in an export-grade wooden crate from NINGBO or SHANGHAI.
Selection Example: Chemical dosing pump drive
Take a 1.1 kW four-pole motor (1400 rpm) turning a dosing pump at 46 rpm. The ratio follows directly: 1400 / 46 = 30.4, so i=30 is selected. In this case the 37 mm frame keeps the dosing skid compact and the worm stage is self-locking on stop. 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.
![gear reducer selection flow chart - ratio and frame size]()
Figure: from motor data to a confirmed gearbox model in four steps.
Common Models in the S Series
| Model | Centre distance | Output | Typical duty |
|---|
| 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 |
| S97 | 97 mm | solid shaft, foot | thickeners, heavy conveyors |
The table below lists the foot-mounted S frames; naming makes selection easy: S = solid shaft with foot mounting, SA = hollow shaft, SF = foot-mounted solid shaft and SAF = hollow shaft with flange - all sharing one gear set and centre distance.
Application Cases
Municipal wastewater plant
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.
Stone quarry conveyor
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.
![industrial gearbox applications - conveyor mixer crusher wastewater]()
Figure: typical industries that use the WGT S-series gear reducers.
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.
What is the difference between SF, S, SA, SAF and SAZ versions?
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.
Can this unit mount on my existing installation without redesign?
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.
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 belt conveyor? Tell us the duty point and we will confirm the model in writing.
