The M3PHT80 shaft mounted industrial gearbox extends the torque-arm construction to the second-largest horizontal frame of the industrial range. A three-stage all-helical train on parallel axes delivers the torque class of kiln, feeder and heavy conveyor drives, while the hollow output slides straight onto the driven machine shaft and a torque arm absorbs the reaction. No base frame, no output coupling, no intermediate pedestal: the drive installs where the machine shaft already is.
The Large Frame Answer for Shaft-Mounted Duty
Most shaft-mounted drives are compact, but heavy plants have large machines that profit from the same installation logic: long overland conveyors, apron feeders, cooler shells and thickener rakes. At size 80 the housing, shafts and bearings carry those duties continuously, and the horizontally split cast-iron case opens for tooth inspection without disturbing the drive. Gearing is case-hardened and ground in every stage, so efficiency holds across the ratio band and running temperature stays predictable through three-shift operation.
What the M3PHT80 Code Specifies
| M3 | Industrial series, three gear stages |
| P | Parallel-shaft helical layout (the R code marks the bevel-helical right-angle build) |
| H | Hollow low-speed shaft - keyed fit or shrink-disc clamping |
| T | Torque-arm mounting on the machine shaft (F would be foot mounted) |
| 80 | Frame size 80, near the top of the horizontal range 50 to 90 |
The same letters run across the whole family, so a buyer who has already standardised on smaller frames can step up to size 80 while keeping spares, oils and inspection routines unchanged - one reason industrial buyers treat the range as a site-wide system rather than a set of individual drives.
Process lines where this build is the standard choice:
- Heavy overland conveyor head drives in mining service
- Apron and pan feeder drives under crushing stations
- Rotary kiln and cooler shell drives in cement and lime works
- Large thickener and sedimentation tank rake mechanisms
- Bucket elevator head shafts on high-lift continuous duty
- Stacker-reclaimer travel and slewing drives in bulk terminals
Where a Size 80 Torque-Arm Build Is Specified
The arrangement appears wherever a large, slow machine shaft is already in place and building a foundation at the drive point is impractical: high-lift elevator head sections, kiln and cooler shells on existing supports, rake mechanisms anchored on a centre column. Because the machine shaft carries the gear unit, the shaft geometry and the torque-arm anchorage are the two points to confirm with the outline drawing before ordering. WGT reviews both against the actual installation details on every enquiry.
Drawings, Selection and Delivery
WGT supplies the M-series catalogue and the size 80 outline drawing as PDF downloads, so the bore, seat and torque-arm bracket can be verified against the machine shaft before any commitment. Send the driven machine, the motor power and speed, the required output speed, the shaft diameter and the running profile; the rated torque is checked against those figures and a written quotation follows. Every unit leaves the factory tested, crated for export and covered by a one-year warranty.
Selection Example: Thickener rake drive
Take a 110 kW motor at 1490 rpm turning a thickener rake shaft at 9 rpm. The ratio follows directly: 1490 / 9 = 165.6, so the three-stage band with a raised service factor covers the slow rake torque. In this case the shaft-mounted build rides the rake centre column, so no foundation or output coupling is built. Work through the same three steps - speed, output speed, torque - and the model number falls out; we verify it against the duty class before quoting.
![gear reducer ratio calculation steps]()
From duty point to model number - the same four steps every time.
Applications in Industry
Coal handling conveyor
A power station coal-handling plant standardized on one industrial gear family for thirty drives. A single spare-part pool now covers the whole conveyor network, from transfer points to the bunker feed.
Dredger pump drive
A dredging contractor powers its slurry pump skid with an industrial gear unit built for shock loads. The dense abrasive mixture demands a rigid drive train, and ground gearing has kept backlash unchanged over multiple seasons.
![gear reducer industries served - WGT]()
Industry map: the sectors where the M3 series is most common.
Buyer Questions and Answers
How is the unit transported and lifted on site?
Units ship in export wooden crates with lifting points on the housing clearly marked. On site, lift only from these points with the specified slings - lifting from shafts or covers is expressly forbidden in the manual.
What tooth quality and grinding finish do you apply?
Gearing is case-hardened and profile-ground to international accuracy grades, with crowning and end relief applied to avoid edge loading. This is what keeps noise and vibration stable over years of continuous duty.
M3 Series Model Overview
| Model | Centre distance | Output | Typical duty |
|---|
| M3PHT80 | size 80 | hollow shaft, torque arm, parallel | shaft-mounted conveyors |
| 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 |
| M3RHT90 | size 90 | hollow shaft, torque arm, right-angle | heavy shaft-mounted drives |
The series is sized for continuous heavy duty rather than by motor power alone: the required torque with the service factor decides the frame, and the stage count (2 to 5) decides the ratio band.
Drawings, Ratings and Test Records on Request
Need the paperwork first? Run your duty point through the WGT Motor & Gearbox Online Selection System first: it saves a round of emails and gets you to a firm price faster.
We issue dimension drawings, rating tables and sample test records in English for your approval package, before the order is placed. Engineering and purchasing sign-off without delays. Looking for a gear reducer for screw conveyor? Tell us the duty point and we will confirm the model in writing.
