At the top of the vertical parallel-shaft band, the M3PVSF90 vertical industrial gear unit takes the three-stage helical concept to its largest foot-mounted frame: a solid keyed output shaft on a vertical centreline, a casting deep enough to keep long process shafts steady, and bearing positions sized for the bending moments that big agitator and pump duties generate. Where smaller vertical frames treat the process shaft as a guest, this one is built around it.
Why Plants Step Up to the 90 Frame
The move up usually follows the shaft, not the torque. A clarifier rake of twelve metres, a digester stirrer or a deep sludge pump multiplies every kilogram of unbalance into the output bearing as bending moment, and moment grows faster than power with frame size. Selecting the 90 frame therefore starts with the shaft drawing and the load directions; the helical stages are then verified against duty, almost always with margin left over.
Reading the Designation
| M | Three-stage industrial gear unit family |
| P | Parallel-shaft helical gearing; R in this slot would mean a bevel input |
| V | Vertical build, output on a vertical axis |
| S | Solid keyed output shaft; H here would denote a hollow bore |
| F | Foot or flange mounting onto a headplate or steel frame |
| 90 | Frame size in the vertical range |
Every letter in the code moves a machined surface, so an order is placed by designation - or by nameplate of the unit being renewed - and never by ratio alone. Two drives with identical ratios can differ in flange drilling, seal variant and oil routing, and only the designation carries those decisions forward.
Lubrication on a Vertical Axis
Standing the gears upright means the upper bearings are fed by cast passages rather than by splash, and the passages are laid out for one declared mounting position. The oil chart is therefore written per posture, and filling is done with the unit in its shipped attitude and at standstill. Three ground helical stages keep the generated heat modest, but the feed paths remain the quiet hero of vertical gearbox reliability.
Service profiles this build is regularly chosen for: Clarifier and thickener rakes on large circular basins Vertical sludge circulation pumps at treatment works Top-entry agitators on bitumen and asphalt tanks Vertical cooling water pumps at power station intakes Scrape and skimmer drives on effluent lamella packs Slow-speed paddle dryers in mineral processing Vertical cargo pumps on tanker ballast systems Digester and anaerobic tank stirring drives
Information to Quote Correctly
A first-pass quotation for this frame needs five facts: absorbed power or output torque, input and output speeds, radial load with direction, axial load with sense, and the mounting face drawing with the keyway detail. Ambient conditions settle the oil grade. Omitting the overhung load is the one omission that consistently costs a redesign, because the output bearing - not the gear teeth - is the limiting component at this size.
Build, Test and Site Life
Units are assembled in the declared posture, proven on a test stand and dispatched sealed and oil-filled in a braced crate, the nameplate fixing ratio, frame and mounting position for any future repeat. On site, commissioning reduces to a flat and square headplate, a bolt sequence, an upright breather and an oil level read at standstill - and a drive that clears those four checks tends to run for decades on nothing but scheduled oil work.
Selection Example: Typical duty point
A typical enquiry for this frame reads like this: 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. That is the whole calculation. If your duty involves heavy starting, frequent reversing or many stops per hour, tell us and we raise the service factor.
Which Frame Size Do You Need?
| 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 |
Foot-mounted frames are listed below; torque-arm (T), hollow-shaft (H) and vertical (V) variants are available across the size range. Ask for the outline drawing to check the interface before ordering.
Answers to Common Questions
Do you supply spare parts such as seals and bearings?
Seal kits, bearings, output shafts and covers are available from stock or on short lead time. We keep the drawings for every unit we ship, so a replacement part ten years from now is still traceable to your original order.
How is each unit tested before shipment?
Every unit is run in on the bench before packing. Noise, temperature rise and backlash are recorded and the test sheet travels with the shipment, so you can file it with your incoming-inspection records.
What payment terms do you accept?
We normally work on 30% deposit and 70% against the bill-of-lading copy for sea freight, or 100% before dispatch for small orders. Other terms can be discussed for framework or repeat business.
![gearbox sizing steps for engineers]()
Four steps from your application data to a firm model number.
Case Notes from the Field
Stone quarry conveyor
A stone quarry runs reducers on its primary conveyor. Shock loads from oversized rock are absorbed by the case-hardened gears (surface HRC58-62), and after two years of continuous duty the units still run within their original 68 dB noise spec.
Flour mill screw conveyors
A flour mill standardised on gear reducers for its screw conveyor network. One spare-part pool now covers fifteen drives, and the smooth helical input stage keeps noise low in the packing hall.
![industrial gear unit application overview]()
A cross-section of the installations we supply every month.
Engineering Support Before You Buy
Unsure about the frame size? Try the WGT Motor & Gearbox Online Selection System, then send the result sheet - we return a complete datasheet, drawing and price the same day.
Our selection engineers check every enquiry against the rating tables, including shock class and daily running hours. You get the calculation, not just a part number - at no charge and with no obligation. Looking for a gearbox for steel mill? Tell us the duty point and we will confirm the model in writing.
