At the upper end of the mid R range sits the R107 inline gearbox - a 107 mm centre-distance, all-helical unit built for the toughest continuous duties. Its large output bearings and ground gearing make it the natural choice for existing R107 installations on thickeners, kiln drives, aerators and heavy material-handling systems.
Why Machine Builders Choose the R107
Because every stage is helical, the R107 speed reducer stays efficient at high ratios where a worm unit would lose ground - and it runs cool enough for 24-hour duty without extra cooling. Keeping the drive on one axis also means the motor and gearbox share a single mounting face, which simplifies the baseplate and often cuts installed cost.
Ratings and Materials
| 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 |
Field experience covers the following sectors:
- Pumps, fans and blowers
- Paper, textile and light industry
- Cranes, hoists and winches
- Mixers, agitators and kneaders
- Mining and bulk material handling
Ordering from WGT
Send the driven-machine data - torque, ratio, duty cycle, ambient temperature - and WGT engineers confirm the R107 selection and quote within one working day. Units ship in reinforced wooden crates via NINGBO or SHANGHAI with full test documentation. One-year warranty, worldwide spare-part support and OEM batch pricing are all available direct from the factory.
How Customers Use This Unit
Pet-food extruder feeder
A pet-food plant chose reducers for the feeder screws ahead of its extruders. Steady torque at variable output speed keeps the kibble size consistent, and washdown sealing protects the unit during sanitation shifts.
Ceramic tile press feeder
A ceramic tile producer fitted reducers to press feeders. The dusty environment is handled by sealed housings, and the stable low-speed output stops the tile blanks shifting before pressing.
What Engineers Ask Us
Do you offer a version with an integrated gear motor?
We can supply the unit as a complete gear motor with an IEC motor bolted on and tested as one assembly. That saves you the alignment and coupling work, and the whole assembly carries the same one-year warranty.
How do I know when the unit needs maintenance?
Beyond routine oil checks, watch for oil weeping at the seals, unusual noise or vibration, and any rise in housing temperature. A seal kit is inexpensive; catching a weeping seal early avoids damage to the bearings and gears.
Model Table: Frames, Shafts and Duty
| Model | Centre distance | Output | Typical duty |
|---|
| R107 | 107 mm | solid shaft, foot | aerators, heavy conveyors |
| 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 |
| R137 | 137 mm | solid shaft, foot | mill drives, large hoists |
| R147 | 147 mm | solid shaft, foot | mill drives, heavy hoists |
| R167 | 167 mm | solid shaft, foot | heaviest inline drives |
Larger frame numbers mean higher torque capacity and a bigger output shaft. Because the centre distances follow the common industry dimensions, a frame change rarely forces a redesign of the driven machine.
Selection Example: Crushed-stone belt conveyor
Take an 18.5 kW motor at 1450 rpm driving the belt at 53 rpm. The ratio follows directly: 1450 / 53 = 27.4, so i=28 with the service factor covered. In this case the 107 mm frame carries the starting torque of a loaded belt. Note that the ratio comes from speeds alone, while the frame size depends on torque and service factor - never size a unit on ratio only.
![helical gearbox selection chart]()
A quick visual of the selection sequence for a helical unit.
![R series gear reducer installation examples]()
Application coverage of the the R series.
Gearbox Selection Support from the Factory Floor
Talk to the people who build it. Prefer to check the figures yourself? The WGT Motor & Gearbox Online Selection System gives you the model, torque margin and ratio before you ask us.
Our technical team sits beside the assembly line, not in a call centre. Describe the application in your own words - we will tell you honestly whether this series is right, or point you to a better frame or a different series. Looking for a reducer for woodworking machine? Tell us the duty point and we will confirm the model in writing.
