The R147 large helical gear reducer is one of the biggest inline units in the WGT range. With a 147 mm centre distance and a heavily ribbed housing, it is built for high torque at low output speed - the sort of duty found on mill drives, large hoists, thickener rakes and heavy conveyors where the drive has to stay on the machine axis and a compact gearbox is the only practical layout.
High Torque on a Single Axis
- Helical gearing with high torque capacity at low output speed
- Heavily ribbed cast-iron / ductile-iron housing, HBS190-240, for impact and torsional stiffness
- Case-hardened 20CrMnTi gears, ground to grade 6~5; 42CrMo shafts at HRC25~30
- Foot, flange or shaft mounting; two- and three-stage builds; solid output with key
R147 Technical Specification
| 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, carburising, 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 | ≤20 µm |
| 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 |
Applications served by this unit in daily operation:
- Mining and bulk material handling
- Belt, screw and chain conveyors
- Cement, lime and aggregate plants
- Cranes, hoists and winches
- Food processing and packaging lines
How the R147 Is Quoted
Because large frames are project items, we quote the R147 against your actual duty point rather than from a list: starting torque, shock level and ambient all influence the final selection, and we would rather be right than approximate. Send the interface drawing, motor power and required output speed, and WGT returns a confirmed model, a dimension drawing and a firm factory price in writing, normally within one working day.
Selection Example: Large thickener rake
Take a 45 kW motor at 980 rpm turning the rake at 8 rpm. The ratio follows directly: 980 / 8 = 122.5, so i=125 is selected. In this case low backlash keeps the rake arms steady when the sludge load changes. That is the whole calculation. If your duty involves heavy starting, frequent reversing or many stops per hour, tell us and we raise the service factor.
Which Frame Size Do You Need?
| Model | Centre distance | Output | Typical duty |
|---|
| R147 | 147 mm | solid shaft, foot | mill drives, heavy hoists |
| R17 | 17 mm | solid shaft, foot | small conveyors, dosing screws |
| R27 | 27 mm | solid shaft, foot | packaging, light agitators |
| R37 | 37 mm | solid shaft, foot | belt conveyors, small mixers |
| R47 | 47 mm | solid shaft, foot | screw conveyors, feeders |
| R57 | 57 mm | solid shaft, foot | mixers, aeration blowers |
| R67 | 67 mm | solid shaft, foot | mixers, extruders |
| R77 | 77 mm | solid shaft, foot | extruders, heavy conveyors |
| R87 | 87 mm | solid shaft, foot | screw conveyors, agitators |
| R97 | 97 mm | solid shaft, foot | thickeners, blowers |
| R107 | 107 mm | solid shaft, foot | aerators, heavy conveyors |
| R137 | 137 mm | solid shaft, foot | mill drives, large hoists |
| R167 | 167 mm | solid shaft, foot | heaviest inline drives |
Foot-mounted frames are listed below; flanged (RF) and shaft-mounted (RS / RFS) versions are available at every frame size. Ask for the drawing set if you need to check the interface.
Answers to Common Questions
Can I reuse my existing couplings and foundations?
Yes. Centre distances, shaft dimensions and flange bolt patterns follow the common industry standards, so couplings, guards and foundations do not have to be redesigned. Send the nameplate details and we confirm the equivalent frame in writing.
Can the reducer be used outdoors or in a washdown area?
Standard paint and NAK seals suit sheltered outdoor duty. For washdown or coastal sites specify the heavy-duty coating, FKM seals and stainless fasteners; for humid rooms we recommend the breather and oil-check routine in the manual.
What if the ratio I need falls between two catalogue steps?
Choose the next available step and adjust the driven speed, or ask us for a special pair of gears. Trimming the driven machine is normally cheaper than ordering a special ratio, and a slightly higher ratio never hurts the drive.
![gearbox sizing steps for engineers]()
Four steps from your application data to a firm model number.
Case Notes from the Field
Glass batch charger
A float-glass line drives its batch charger with units. Abrasive raw material demands a robust drive, and the case-hardened gears show minimal wear after years of continuous operation.
Battery slurry mixer
A battery materials plant uses reducers on slurry mixers. High shear loads are absorbed by the 42CrMo shafts, and the 94-96% efficiency keeps motor sizing and running cost down.
![industrial gear unit application overview]()
A cross-section of the installations we supply every month.
Request the Datasheet and Dimension Drawing
Need documentation for approval? Try the WGT Motor & Gearbox Online Selection System, then send the result sheet - we return a complete datasheet, drawing and price the same day.
We issue complete technical files on request: dimension drawing, rating table, test record format and material certificates, in English and ready for your engineering or purchasing approval package. Looking for a gearbox for packaging machine? Tell us the duty point and we will confirm the model in writing.
