Conveyor, agitator and elevator builders keep coming back to the S57 speed reducer gearbox because it pairs a high reduction ratio with a right-angle output in very little space. The helical input stage absorbs motor speed down to an intermediate level and the worm stage completes the reduction, so the driven machine sees smooth torque without the whine typical of an all-helical drive at the same ratio.
Built for Conveyor and Agitator Duty
- Foot and torque-arm mounting; solid or hollow output for direct chain or shaft coupling
- Efficiency 94~96% with a maximum housing rise of 40 °C, even in long continuous shifts
- Standard interface dimensions - existing brackets and guards are reused
- Optional anti-run-back device for inclined conveyors and inclined screws
- NAK (Taiwan) oil seals as standard; FKM available for hot or wash-down areas
S57 Technical 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) | 60~68 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 |
Proven in service across these industries:
- Conveyors, mixers, agitators and hoists
- Building and construction machinery
- Agriculture and food processing
- Mining and bulk material handling
- Metal processing and forming lines
Quality and Warranty
Each S57 gear reducer is ground on modern gear grinders and run-in on a no-load test rig before dispatch. A one-year warranty covers material and workmanship, and spare seal and bearing kits are held in stock. Ask for the dimensional drawing or a completed datasheet with your ratio and duty cycle - we usually reply the same working day.
Field Applications
Automatic car-wash line
A car-wash equipment builder fits SA57 hollow-shaft reducers to its conveyor chains. The compact frame hides inside the wash tunnel, and FKM seal options handle the constant moisture.
Textile dyeing drums
A dyeing machine maker uses SF67 speed reducers on its fabric-turning drums. Low vibration (under 20 microns) prevents streaks in the fabric, and the 94-96% efficiency keeps the heat load down in a warm workshop.
![where gear reducers are used in industry]()
Where these units are installed across industry.
Selection Example: Filter-press feed pump
Take a 3 kW motor at 1440 rpm turning the feed pump at 36 rpm. The ratio follows directly: 1440 / 36 = 40, so i=40 is chosen. In this case the helical input stage keeps efficiency up where a plain worm unit would fall away. Once the ratio is fixed, check the required output torque against the rating table with the service factor applied - that is what decides the frame, not the ratio alone.
![gearbox selection guide: speed, torque, service factor]()
How a ratio and a frame size are determined, step by step.
Frame Sizes and Typical Duties
| Model | Centre distance | Output | Typical duty |
|---|
| S57 | 57 mm | solid shaft, foot | bagging belts, stirrers |
| S37 | 37 mm | solid shaft, foot | dosing screws, small conveyors |
| S47 | 47 mm | solid shaft, foot | packaging, small mixers |
| 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 |
Read the frame number as the centre distance in millimetres. Shaft and mounting styles are separate choices: solid shaft (S), hollow shaft (SA), flanged hollow shaft (SAF) and torque arm (SAZ).
From Duty Point to Delivery in One Working Day
Stop guessing the ratio. Engineers can size the unit themselves in the WGT Motor & Gearbox Online Selection System - input speed, torque and duty, get the model instantly.
Tell us what the machine does and how hard it works; we calculate the ratio, apply the service factor and send back the drawing and quotation within one working day, including sea-freight and air-freight options. Looking for a gearbox for mixer and agitator? Tell us the duty point and we will confirm the model in writing.
Common Questions from Buyers
How do I choose between a helical-worm and a helical-bevel gearbox?
For a right-angle drive at a moderate ratio and the lowest cost per unit, a helical-worm unit is normally the better buy. When the ratio is low and efficiency is the priority, a helical-bevel (K series) unit wins - it holds 96% and above at any ratio, while the worm stage loses a little efficiency as the ratio grows.
What mounting positions (M1 to M6) are available?
The S series supports M1 to M6 mounting positions, so the unit can be installed on its base, wall or ceiling. The oil level plug is repositioned accordingly; state the position when ordering so the unit is filled and labelled correctly.
Can the reducer be supplied with a brake motor or an IEC motor flange?
Yes. We supply the reducer as a bare unit with an IEC standard input flange, and you can bolt on any IEC or NEMA motor - including a brake motor. The flange dimensions follow the common IEC pattern, so existing motors drop straight on.
