The M3PHF80 gear unit takes the hollow-output, foot-mounted formula of the industrial range up to the size 80 frame. Three parallel helical stages handle the ratio and the torque; the low-speed shaft is a bored quill that clamps or keys onto the driven machine shaft; and the housing bolts to a standard foot pad rather than hanging on a torque arm. It is the arrangement selected when a large machine shaft needs a driven end but a base frame is still available.
The Size 80 Frame for Shaft-Mounted Outputs
Size 80 steps up the torque class of the range without changing the working method. The case is split horizontally so the gear train can be inspected in place, the helical wheels are case-hardened and ground, and the bearing arrangement is dimensioned for the radial pull of a large head pulley or sprocket acting near the end of the output shaft. Because the output is a hollow quill rather than a solid extension, the overall length of the drive train stays short - often the deciding factor where the machine sits close to a wall, a chute or a structural column.
Reading the M3PHF80 Designation
| M3 | Industrial gear unit series, three gear stages |
| P | All-helical gearing on parallel axes (R adds a bevel right-angle input stage) |
| H | Hollow low-speed shaft with key or shrink-disc connection (S marks solid output) |
| F | Foot mounting on standard foundations (T marks torque-arm mounting) |
| 80 | Frame size 80, upper half of the horizontal band 50 to 90 |
Because the code separates function from size, a plant can move up the frame ladder while keeping the same shaft connection and the same maintenance routine. That continuity matters on installations with many drive points: one oil grade, one inspection checklist and one spares list cover the whole site instead of a different procedure at every machine.
The machines this unit is routinely paired with:
- High-capacity belt conveyors in open-pit and port bulk handling
- Tube and ball mill drive stations on grinding circuits
- Bucket elevator head sections inside cement storage towers
- Rotary kiln and dryer drives without a separate foundation block
- Heavy-duty mixers and kneaders in chemical process lines
- Stacker, reclaimer and shiploader travel and boom drives
Where This Frame Is Specified
The hollow-shaft foot build suits drive points where the machine shaft is short, stiff and already supported by the driven equipment: head pulleys on heavy belt conveyors, elevator head shafts, feeder shafts under hoppers, and mill or drum drives on their own bearings. It is a good fit wherever a foundation is available but an output coupling is not wanted, and where the alignment of two separate shafts would be a recurring burden. Where the machine shaft is long or lightly supported, WGT advises the torque-arm variant or a solid-shaft build before the drawing is issued.
Enquiry, Drawing and Delivery
WGT supplies the M-series catalogue and the size 80 outline drawing as PDF downloads, so the bore diameter, keyway or shrink-disc seat, foot bolt pattern and motor interface can be confirmed against the actual installation. Send the driven machine, the motor power and speed, the required output speed, the machine shaft diameter and the daily running profile; the selection is verified with a rated-torque check and a written quotation follows. Units ship factory-tested in an export wooden crate with a one-year warranty.
Full Frame Range of the M3 Series
| Model | Centre distance | Output | Typical duty |
|---|
| M3PSF50 | size 50 | solid shaft, foot | conveyors, feeders |
| M3PSF60 | size 60 | solid shaft, foot | crushers, mixers |
| M3PSF70 | size 70 | solid shaft, foot | ball mills, shredders |
| M3PSF80 | size 80 | solid shaft, foot | kilns, heavy conveyors |
| M3PSF90 | size 90 | solid shaft, foot | mill and kiln drives |
| M3RSF50 | size 50 | solid shaft, foot, right-angle | inclined conveyors, elevators |
| M3RSF60 | size 60 | solid shaft, foot, right-angle | screw classifiers, feeders |
| M3RHF70 | size 70 | hollow shaft, foot, right-angle | agitators, drum drives |
| M3PHT80 | size 80 | hollow shaft, torque arm, parallel | shaft-mounted conveyors |
| M3RHT90 | size 90 | hollow shaft, torque arm, right-angle | heavy shaft-mounted drives |
Every frame in the table can be ordered with alternative shaft and mounting styles. If you are matching an existing installation, send the nameplate details and we confirm the equivalent frame in writing.
Installation Snapshots
Stone quarry conveyor
A stone quarry runs reducers on its primary conveyor. Shock loads from oversized rock are absorbed by the case-hardened gears (surface HRC58-62), and after two years of continuous duty the units still run within their original 68 dB noise spec.
Flour mill screw conveyors
A flour mill standardised on gear reducers for its screw conveyor network. One spare-part pool now covers fifteen drives, and the smooth helical input stage keeps noise low in the packing hall.
Selection Example: Typical duty point
Work through the numbers for this frame: Motor speed divided by the target output speed gives the ratio, rounded to the nearest available step, and the required torque with the service factor then fixes the frame size. 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
What materials are used for the gears and shafts?
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.
Why does low backlash matter, and what is the limit?
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.
![speed reducer use cases across sectors]()
Typical installation environments for this gearbox family.
Torque Margin Checked Before Every Quotation
No catalogue guessing. 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.
Every quotation includes the calculated service factor and the resulting torque margin, so the unit you buy covers the real duty - including starts, jams and reversals - not just the average load. Looking for a gear reducer for food processing machine? Tell us the duty point and we will confirm the model in writing.
