The M3PVHF80 vertical hollow shaft gear unit is the large vertical frame with the bore in the output: the process shaft climbs through the gear unit, is captured inside the bore, and the housing itself carries the thrust and the radial load. On a deep sump pump, a cooling tower fan or a thickener rake, that arrangement deletes the top bearing pedestal and the long coupling that a solid-shaft build would need, and it puts every alignment problem inside one machined part.
Sizing Against the Shaft, Not the Torque
The selection conversation for a hollow vertical unit starts with the load path. Fluid unbalance and shaft whip produce the radial component; whether the machine pushes down or pulls up produces the axial one. At frame 80 the bore and its bearing set are rated for a broad band of shaft diameters, but the numbers still have to be stated - a five-metre rake arm and a short fan stack load the same bore in very different ways. Torque rarely governs at this size, which is why a competent quotation asks for the shaft drawing before it asks for the duty point.
What the Letters Say
| M | Three-stage industrial gear unit family |
| P | Parallel-shaft helical gearing throughout |
| V | Vertical axis, output directed down into the process |
| H | Hollow output shaft bored for the through-going process shaft |
| F | Foot and flange mounting on a headplate or steel structure |
| 80 | Frame size in the vertical range |
Seals and the Lower Bearing
The two components that decide whether a vertical hollow unit is loved or cursed are the shaft seal and the lower output bearing. The seal is chosen for the atmosphere directly beneath it - steam above a hot vessel, mist above a scrubber, dust above a powder silo - and the bearing sees every newton the process shaft generates. Ground helical stages keep the gear noise low and the losses modest, but neither gearbox-grade polish nor generous ratios can rescue a seal grade chosen as an afterthought. Specify the environment honestly and the drive repays it for years.
Machine groups this unit is specified into: Cooling tower and spray pond fans on tall steel stacks Vertical process pumps in deep sumps at paper mills Sludge recirculation stirrers at wastewater outfalls Big-bag and silo centre drives on powder discharge Vertical evaporator and crystalliser agitators Line-shaft well pumps on broad acreage irrigation Desalination intake and brine circulation pumps Vertical thickener rakes in hydrometallurgical plants
Mounting Discipline
The headplate face must be machined flat and square; tilt transfers straight into the bore and the seal lip. Shaft end float is set to the drawing so process and unit bearings share the thrust as intended, the breather goes in the vertical-service position, and the oil level is read with the unit in its shipped posture at standstill. Torque reaction belongs to the housing flange, never to the shaft, which is why the bolt circle deserves as much care as the bore itself.
Documentation and Delivery
Every unit ships with a dimensional drawing, an oil chart written per mounting position and a nameplate that fixes ratio, frame and arrangement for future repeat orders. Bore diameter, keyway or shrink-disc detail and the seal variant are agreed before release, so the delivered machine matches the drawing set the plant files. Transit packing is a braced crate with the bore plugged against dust, and the commissioning spares - seals and fasteners - ride inside the crate, because the parts a site needs first are the ones it should never hunt for.
How Customers Use This Unit
Lime kiln auxiliary drive
A lime producer fits a smaller industrial gear unit as the auxiliary drive of its rotary kiln. Turning the kiln slowly during shutdowns and start-ups is exactly the low-speed, high-torque duty the frame was chosen for.
Tunnel boring backup drive
A tunnelling contractor uses industrial gear units on the backup gantry conveyors of its TBM. The units arrived dimensionally matched to the gantry interfaces, so installation took hours rather than days.
What Engineers Ask Us
Can I get a CAD drawing or 3D model for my design review?
Yes. Send us the model and ratio and we provide a 2D dimension drawing and a 3D STEP model for your review, usually the same working day. Drawings follow the layout of the original series so they drop into your existing assembly.
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.
Model Table: Frames, Shafts and Duty
| 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 |
Larger size numbers mean higher torque capacity and larger shafts. Because interfaces follow the common industrial dimensions, a size-for-size change is the normal upgrade route for these industrial units.
Selection Example: Typical duty point
Follow the same three steps with 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. Note that the ratio comes from speeds alone, while the frame size depends on torque and service factor - never size a unit on ratio only.
![industrial helical gearbox selection chart]()
A quick visual of the selection sequence for a industrial helical unit.
![M3 series gear reducer installation examples]()
Application coverage of the the M3 series.
Shutdown Planned? Order Ahead of the Window
Beat the shutdown window. Prefer to check the figures yourself? The WGT Motor & Gearbox Online Selection System gives you the model, torque margin and ratio before you ask us.
For planned maintenance windows we reserve production capacity and ship the unit ahead of the shutdown date, so the swap takes hours instead of days. Tell us the window and we work back from it. Looking for a gear motor for car wash system? Tell us the duty point and we will confirm the model in writing.
