The M3PSF80 industrial gear reducer is the second-largest horizontal frame in the M-series foot-mounted line, matched in dimensions and duty to the size 80 industrial standard. A three-stage helical train on parallel axes turns a high-speed motor input into a slow, high-torque output suitable for the heaviest continuously rated machinery in a plant: kiln drives, large shredders, primary crushing stations and continuous bulk unloaders.
Built for the Largest Drives in the M-Series Range
At this frame the gear unit is less a component and more the structural heart of the drive train. The cast housing is sized so the slow-speed shaft can carry a large keyed coupling without deflecting beyond its limits, and the bearing arrangement is chosen for the long service intervals that heavy plant expects between planned shutdowns. Gearing is case-hardened and ground, and all three stages are helical, so the drive holds efficiency over the full ratio band instead of trading it away for ratio coverage.
How Size 80 Differs from the Smaller Frames
| Torque capacity | Rated for the continuous duty of mills, shredders and unloaders rather than intermittent peaks |
| Bearing and shaft size | Larger low-speed shaft and bearings, so overhung load from pulleys and sprockets is absorbed without extra supports |
| Thermal capacity | Bigger oil sump and cooling surface for three-shift operation without derating |
| Mounting | Foot mounted to standard foundations; hollow-shaft and torque-arm versions available in the same housing |
| Stage count | Three stages as standard, with four and five-stage builds for very high ratios |
Plants that already run size 70 or size 90 frames will recognise the interface philosophy immediately: horizontally split housing for internal inspection, a foot pattern that matches the industry standard, and the same ordering letters for output shaft and mounting. That consistency means an upgrade to size 80 rarely demands new foundations or a redesigned guard set.
Where this frame size is regularly specified:
- Large single-shaft shredders and tyre recycling lines
- Open-pit mine conveyor drives and semi-mobile crushing stations
- Cement kiln drives and roller presses for clinker grinding
- Port bulk unloaders and continuous ship unloaders
- Alumina and bauxite refinery agitators and thickener drives
- Wind tunnel fans and heavy process high-pressure blowers
Where This Frame Size Earns Its Place
The size 80 frame is chosen when the duty point sits above what the smaller frames can carry continuously but the plant still wants the compact parallel-shaft layout rather than a right-angle unit. It is a common standard in cement, mining and bulk material handling, and it is often the drive behind machines that are too central to the process to accept unplanned stops. Sizing it correctly, with a real duty cycle and not just a nameplate power figure, is what keeps that promise.
Getting a Selection Confirmed
WGT provides the M-series catalogue and the size 80 outline drawing as PDF downloads so dimensions, shaft height and bolt pattern can be checked up front. Send the driven machine, the motor power and speed, the required output speed and the running hours per day; the selection is confirmed against those inputs and returned as a written quotation. Each gear unit leaves the factory tested, crated for export and covered by a one-year warranty.
Model Range and Centre Distances
| Model | Centre distance | Output | Typical duty |
|---|
| M3PSF80 | size 80 | solid shaft, foot | kilns, heavy 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 |
| 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 |
Frame sizes in this series follow a widely used industrial dimension ladder: foundations, couplings and guards of the existing installation are reused as they are.
Proven Installations
Dust-extraction fan bank
An environmental-equipment plant uses reducers on the rotary valve feeders of its dust-extraction systems. Compact size, quiet running and food-grade oil options made the approval easy.
Steel mill run-out table
On the run-out table of a small steel mill, units handle the repeated starts and stops of hot billet handling. The 42CrMo output shafts tolerate the thermal cycling, and torque-arm mounting keeps the drive clear of the roller frames.
![gearbox applications in quarry food and water plants]()
Conveyor, mixer, crusher and wastewater duties share the same gear family.
Selection Example: Typical duty point
Here is how the selection is made for this frame size. 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. Motor speed over target speed gives the ratio; the driven machine decides the service factor, and the two together decide the model.
![industrial gear unit sizing procedure diagram]()
The four inputs the online selector asks for.
Tell Us the Torque, We Confirm the Model
Not sure where to start? Work out the ratio, torque and frame size yourself with the WGT Motor & Gearbox Online Selection System, then send the result - we confirm it in writing.
A photo of the nameplate, the motor power and the output speed you need are enough to start. We confirm the frame size, ratio and mounting style and return a written quotation the same day. Looking for a speed reducer for bucket elevator? Tell us the duty point and we will confirm the model in writing.
FAQ: Selection, Mounting and Maintenance
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.
Do you offer food-grade or washdown versions?
We can supply food-grade lubricant, FKM (Viton) oil seals and stainless fasteners for washdown areas. These units are common in bakeries, dairies and packaging halls where hygiene and moisture are daily concerns.
