The M3RHF80 right angle gearbox answers two layout constraints with a single size 80 industrial housing: a spiral-bevel input stage that redirects the motor through 90 degrees, and a hollow low-speed shaft that accepts the machine shaft straight into the output bore. The drive train ends up shorter than any coupled arrangement - no motor projecting along the machine axis, no flexible coupling to age, no pedestal bearing to grease.
Two Layout Problems Solved by One Size 80 Housing
Layout is the first problem. Where a machine sits close to a wall, a chute or a structural column, an inline unit and its motor simply do not fit; the bevel stage turns the drive into the available space. Mechanics are the second: a hollow output removes the coupling and with it the alignment that drifts after foundation settlement, which matters most on equipment that is hard to reach. At size 80 the frame carries enough torque for continuous duties while still fitting the small pad the machine interface provides, and all gearing - bevel and helical - is case-hardened and ground.
How to Read the M3RHF80 Name
| M3 | Industrial gear unit family, three gear stages |
| R | Bevel input stage giving a right-angle drive (P keeps every stage parallel) |
| H | Hollow low-speed shaft, keyed or shrink-disc mounted (S marks a solid output) |
| F | Foot mounting on a standard base (T marks torque-arm reaction) |
| 80 | Frame size 80, upper half of the horizontal band 50 to 90 |
The code is compositional, so it is worth knowing what each position buys. Swapping P for R turns the drive through 90 degrees without changing frame size. Swapping H for S changes the output connection, not the torque class. Swapping F for T changes how the reaction torque is taken away from the unit. One dimension ladder covers all of those choices, which is why plants standardising on this range keep one spares philosophy across dozens of drive points.
Drivetrain duties this frame answers to:
- Inclined trunk conveyors where the motor must sit clear of the belt line
- Bucket elevator head shafts driven straight off the hollow output bore
- Rotary kiln inlet and discharge screw conveyors in cement lines
- Twin-shaft paddle mixers and continuous blenders in chemical plants
- Rotary drum dryers and coolers with the drive alongside the shell
- Portal and gantry structures using right-angle travel drive units
Installations Built around the Right-Angle Hollow Build
The combination is specified where the machine shaft is short, stiff and already carried by its own bearings, and where the motor has to sit off the machine axis: inclined conveyors running beside a wall, elevator head sections inside a tower, rotary feeders under silos, kiln inlet screw conveyors. Removing the coupling also removes the flexible element that ages and the pedestal bearing that needs attention, which pays off on drives that run unattended. 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.
From Enquiry to Crating
WGT supplies the industrial range catalogue and the size 80 outline drawing as PDF downloads, so the bore diameter, keyway or shrink-disc seat, foot pattern and motor interface can be confirmed against the installation. Send the driven machine, the motor power and speed, the required output speed, the machine shaft diameter and the number of running hours per day; the selection is verified with a rated-torque check against the duty service factor and a written quotation follows. Each unit ships factory-tested in an export wooden crate with a one-year warranty.
The M3 Series at a Glance
| 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 |
All frames in the table belong to one industrial family. P = helical parallel-shaft, R = bevel-helical right-angle; the low-speed shaft is solid (S) or hollow (H), mounted on feet (F) or a torque arm (T).
Selection Example: Rotary kiln inlet screw drive
Take a 90 kW motor at 1480 rpm turning a kiln inlet screw conveyor shaft at 15 rpm. The ratio follows directly: 1480 / 15 = 98.7, so a ratio near i=99 is selected. In this case the bevel input turns the motor clear of the kiln shell while the hollow bore slides onto the screw shaft without a coupling. That single division gives the catalogue ratio; the service factor for your duty class is then applied to the torque, and the frame size follows.
![how to size a industrial helical gearbox in four steps]()
Sizing flow: motor speed, target output speed, torque, service factor.
Where This Series Works in Practice
Grain terminal elevators
A grain terminal powers its bucket elevators with gear reducers. The anti-run-back option holds the loaded buckets during power cuts, and standard interface dimensions meant the old foundations were reused as they were.
Pallet lift in a warehouse
A logistics integrator selected units for pallet lifts. The hollow output bore carries the lift screw directly, and one year of three-shift operation has passed without a single seal replacement.
Technical Questions, Answered
What is the recommended oil change interval?
The housing is lubricated for life under normal duty and normal ambient. In hot, humid or continuous service, change the oil after the first 400 running hours and then every 4000 hours, or once a year, whichever comes first.
What paint finish and corrosion protection is applied?
Housings are shot-blasted and finished with a two-component industrial paint in RAL colours, giving good protection for indoor and sheltered outdoor duty. For aggressive or coastal sites, ask for the heavy-duty coating option.
![industrial helical gear reducer application fields]()
Common application areas for right-angle industrial helical drives.
Full Documentation for Project Tenders
Bidding a project? Skip the back-and-forth: configure your drive in the WGT Motor & Gearbox Online Selection System and send us the result for a same-day quotation.
We support tenders with complete technical files: dimension drawings, rating tables, material certificates and test record formats, in the format your client specifies. Looking for a reducer for woodworking machine? Tell us the duty point and we will confirm the model in writing.
