Delivery time: 5-10 weeks Warranty: one year Supply capacity: 600 sets/month Port: NINGBO / SHANGHAI PORT Packing: Standard export wooden crate
The S77 gear reducer moves the S concept into medium-torque territory. Its 77 mm centre distance and generously sized output shaft make it a natural fit for existing S77 installations on mixers, feeders, elevators and heavy conveyors. For machine builders the appeal is simple: one compact right-angle speed reducer that reaches ratios a two-stage worm unit cannot manage without losing efficiency.
| 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 |
Where customers install this frame:
Units are rust-protected, boxed with an installation manual and packed in export-grade wooden crates for NINGBO or SHANGHAI shipment. WGT supports every S77 with a one-year warranty, spare seal and bearing kits, and engineering advice on mounting position and oil change intervals. Send your specification and we reply with drawings, a torque table and a firm price.
Gears are 20CrMnTi alloy steel, case-carburised to HRC58-62 over a tough HRC33-40 core. Input and output shafts are 42CrMo, quenched and tempered to HRC25-30. The housing is cast iron at HBS190-240.
Backlash is the small free rotation between input and output. We hold it within 20 arcmin - tight enough for indexing tables, positioning drives and reversing applications, without the cost of a precision servo gearbox.
Yes, the S series runs equally well in both directions. If the load must be held when the motor stops - an inclined conveyor, for example - specify the anti-run-back or self-locking option.
| Model | Centre distance | Output | Typical duty |
|---|---|---|---|
| S77 | 77 mm | solid shaft, foot | turntables, elevators |
| 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 |
| S87 | 87 mm | solid shaft, foot | screw conveyors, washers |
| S97 | 97 mm | solid shaft, foot | thickeners, heavy conveyors |
One gear set, many mountings. Pick the frame size for the torque you need, then pick the mounting style - solid shaft, hollow shaft, flange or torque arm - to suit your machine.
Take a 5.5 kW motor at 960 rpm rotating a turntable at 12 rpm. The ratio follows directly: 960 / 12 = 80, i=80 within one unit. In this case low backlash keeps the stacking position repeatable shift after shift. It always comes down to those three figures. Send them over and we confirm the frame, ratio and service factor in writing.

Selection workflow used by our engineers for every quotation.
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.
An environmental-equipment plant uses SF47 reducers on the rotary valve feeders of its dust-extraction systems. Compact size, quiet running and food-grade oil options made the approval easy.

An overview of the duty points this series is built for.
Send the numbers, get the model. Use the WGT Motor & Gearbox Online Selection System to turn your motor data into a model number, and we will quote that exact unit within the day.
Every enquiry is checked by an engineer against the rating tables before it is quoted, so the unit we recommend carries a real torque margin - not just a catalogue guess. Spare-unit and OEM volumes are both welcome. Looking for a gearbox for wastewater treatment? 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
Supply capacity: 600 sets/month Delivery time: 5-10 weeks Packing: Standard export wooden crate Port: NINGBO / SHANGHAI PORT Warranty: one year
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