At the top of the WGT R range sits the R167 heavy duty helical gearbox - a 167 mm centre-distance unit for the heaviest inline drives. It carries the same design language as the rest of the series, but everything is scaled for maximum torque: a thicker housing, larger bearings, bigger shafts and generously sized gearing, all arranged so the motor sits directly behind the driven shaft.
The Largest Frame in the R Range
- Very high torque capacity in a coaxial, single-axis envelope
- Impact-resistant cast-iron / ductile-iron housing at HBS190-240
- 20CrMnTi gears at HRC58~62 over a HRC33~40 core, precision ground to grade 6~5
- 42CrMo input and output shafts, quenched and tempered to HRC25~30
Specification Table
| 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 |
Sectors where this gear unit is a common sight:
- Food processing and packaging lines
- Wastewater treatment and water supply
- Paper, textile and light industry
- Extruders and plastics machinery
- Belt, screw and chain conveyors
Ordering, Test Records and Warranty
WGT supplies the R167 gear reducer direct from the factory with the same documentation as the smaller frames: dimension drawing, rating table, and a pre-shipment test record covering noise, temperature rise and backlash. A one-year warranty covers material and workmanship, and spare seal, bearing and shaft kits remain traceable to your original order. Tell us the driven machine and the duty cycle, and our engineers confirm the model and price in writing - no obligation, no charge for the selection work.
Full Frame Range of the R Series
| Model | Centre distance | Output | Typical duty |
|---|
| R167 | 167 mm | solid shaft, foot | heaviest inline drives |
| 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 |
| R147 | 147 mm | solid shaft, foot | mill drives, heavy hoists |
Every frame in the table can be ordered for foot, flange or shaft mounting, in two-stage or three-stage build. If you are unsure which combination your machine needs, send us the interface drawing.
Installation Snapshots
Asphalt plant aggregate feeder
An asphalt plant powers its aggregate feeders with reducers in outdoor, dusty conditions. The cast-iron housing and standard paint finish have come through several winters without refurbishment.
Fertiliser granulator drum
A fertiliser producer drives granulator drums with gear units. The slow, high-torque rotation needed to tumble the granules is a natural fit, and the torque-arm option avoids a heavy base frame.
Selection Example: Heaviest inline duty - wet scrubber
Take a 55 kW motor at 980 rpm turning the scrubber shaft at 6 rpm. The ratio follows directly: 980 / 6 = 163, so i=160 is chosen. In this case the top frame gives the torque margin a shock-loaded scrubber needs. Use the same method for any frame in the series, then confirm the service factor with us - it is the one number buyers most often get wrong.
![speed reducer selection process diagram]()
The selection path we follow when checking your enquiry.
Technical Q&A
How is the unit protected against dust and water ingress?
Housings are sealed to IP55 as standard with NAK oil seals and gasketed covers. Heavy dust, washdown chemicals or steam cleaning call for the higher protection option, which we specify together with the correct lubricant.
Do you support commissioning and after-sales service?
Every shipment includes an installation manual and a test record. Our engineers answer commissioning questions by e-mail or video call, and spare seals, bearings and shafts remain traceable to your original order for years afterwards.
![speed reducer use cases across sectors]()
Typical installation environments for this gearbox family.
Sample Units Available for Performance Testing
Validating before you commit? One screen in the WGT Motor & Gearbox Online Selection System is usually enough to pin down the frame size; we confirm the service factor afterwards.
Sample units can be supplied for bench or field testing so your team can confirm noise, temperature rise and backlash before a production order. Tell us the test conditions and we will prepare the documentation. Looking for a gear motor for car wash system? Tell us the duty point and we will confirm the model in writing.
