The M3PVSF70 vertical industrial gear unit carries the vertical parallel-shaft family up into its mid band: three helical stages in a foot-mounted housing that sits flat on a vessel head, a walkway or a fabricated steel frame, with a keyed solid shaft entering the process from above. At size 70 the casting, shaft section and bearing set step up together, and the frame becomes the natural home for duties where a smaller vertical unit would be running close to its bearing limit every hour of the shift.
Why Plants Step Up to the Mid-Band Frame
The decision to move from the smaller vertical frames to size 70 is rarely about torque alone. Long agitator shafts and deep pump columns put bending moment into the output bearing that grows with the square of the overhang, so a duty that looks easy on paper can be hard on a light frame in practice. Stepping up buys a bigger bearing envelope, a stiffer housing and more metal around the lower bearing - which is the one part of a vertical drive that never gets easy access once the vessel is in service. Engineers who size this band honestly get drives that run cool for twenty years; engineers who size to the catalogue minimum get bearings.
Type Code, Read Line by Line
| M | Three-stage industrial gear unit family |
| P | Parallel-shaft helical gearing; R in this position would mean a bevel input |
| V | Vertical mounting, output shaft on a vertical axis |
| S | Solid keyed output shaft; H in this position would give a hollow bore |
| F | Foot or flange mounting on a horizontal face |
| 70 | Frame size, mid band of the vertical range |
Each letter in the designation changes a drawing, and the drawing is the contract: the mounting face, the shaft detail and the seal arrangement all follow from it. Ordering from the code on an old nameplate is therefore the safest route to a unit that bolts straight onto an existing installation.
Heat, Oil and a Vertical Axis
Lubrication is where vertical builds differ most from their horizontal cousins. The lower bearing sits below the oil level on some mounting positions and above it on others, so splash alone cannot be trusted; the internal oil passages are cast and drilled to feed the upper bearings by design, and the oil grade is chosen for the ambient temperature at site. Three ground helical stages keep the losses low to begin with, so the unit does not need to shed much heat, but what little it does shed has to leave through a housing that is partly immersed in the product it serves. That is why the oil chart shipped with the unit is written per mounting position rather than per frame.
Service profiles this build is regularly chosen for: Bridge agitators on clarifier and thickener duty Vertical screw conveyors lifting grain into silos Top-entering mixers on effluent neutralisation tanks Cooling tower and condenser fan stacks Vertical froth pumps in mineral flotation cells Rotary airlock feeders under silo discharge cones Column stirrers on polymer and resin reactors Vertical seawater lift pumps on intake caissons
Specifying One Without Guesswork
A complete enquiry for a vertical parallel-shaft frame carries five numbers: the driven torque or the absorbed power at the shaft, the input and output speeds so the ratio falls out exactly, the overhung load in newtons with its direction, and the axial load with its sense - down for most agitators, up for fans and some pump arrangements. Add the vessel head or frame drawing for the mounting face and the shaft keyway detail, and the selection can be closed in one pass. Leaving out the overhung load is the single most common cause of a vertical frame that is correct on torque and wrong in service.
From Works Test to Site Start
Every frame is assembled for its declared mounting posture, run on a test stand and shipped sealed and oil-filled in a wooden crate. The nameplate records ratio, frame and mounting position, so a unit ordered against that plate years later arrives in the same mechanical arrangement. On site, the checklist is short: face flat and square, bolts torqued in sequence, breather in the vertical position, oil level read at standstill. Follow it and the drive starts as if it had never left the works.
Questions We Hear Most Often
Can the reducer be supplied with a brake motor or an IEC motor flange?
Yes. We supply the reducer as a bare unit with an IEC standard input flange, and you can bolt on any IEC or NEMA motor - including a brake motor. The flange dimensions follow the common IEC pattern, so existing motors drop straight on.
What is the service factor and how is it applied?
The service factor is a multiplier applied to your required torque to cover shocks and duty class - typically 1.0 for uniform duty, 1.25 for moderate shocks, 1.5 or more for heavy shock loads. Send us the driven machine and duty and we will apply the correct factor.
What ambient temperature range can the unit work in?
Standard units suit -10 to +40 deg C ambient with the supplied mineral oil. For lower temperatures we fill with synthetic oil; for higher ambient or frequent starting we advise the next larger frame or an oil cooler.
Choosing the Right Frame Size
| 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 |
One family, two layouts. Choose P for a coaxial-in / parallel-out drive train, R when the motor must turn 90 degrees; then pick the shaft type and mounting style that the machine interface needs.
Selection Example: Bridge agitator on a clarifier centre column
Take a 45 kW motor at 1480 rpm turning the agitator shaft at 22 rpm. The ratio follows directly: 1480 / 22 = 67.3, so a ratio near i=67 is drawn from the three-stage band and the frame is checked against the overhung moment of a long paddle shaft. In this case the solid output shaft lands on the agitator coupling with the unit bolted to the bridge deck, so the only moving joint above water is the shaft seal. It always comes down to those three figures. Send them over and we confirm the frame, ratio and service factor in writing.
![online gearbox selection system workflow]()
Selection workflow used by our engineers for every quotation.
Real-World Duty Points
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.
![right angle gearbox duty points overview]()
An overview of the duty points this series is built for.
Sample Units Available for Performance Testing
Validating before you commit? Use the WGT Motor & Gearbox Online Selection System to turn your motor data into a model number, and we will quote that exact unit within the day.
Sample units can be supplied for bench or field testing so your team can confirm noise, temperature rise and backlash before a production order. Tell us the test conditions and we will prepare the documentation. Looking for a gearbox for crusher? Tell us the duty point and we will confirm the model in writing.
