The M3PVHF30 vertical hollow shaft helical gearbox is the bored-output version of the compact upright parallel line: the process shaft passes straight through the housing and the drive grips it with a key or shrink disc, so no coupling exists anywhere in the train. All-gear stages are helical, which keeps the mesh quiet, and the short housing lets the unit hang inside covered vessels, kettles and small basins where headroom is the binding constraint.
Why the Bore Changes the Game at Small Size
On small vertical drives the coupling is often the highest-friction item in the whole installation - it needs alignment, spacers and guard space that a cramped vessel top does not have. The bored output removes that hardware entirely: the shaft enters the bore, end float is set against the drawing, and the clamping element carries the torque. Dismounting is the reverse operation, so an agitator shaft can be pulled for cleaning without touching the gear unit at all.
The cost of that convenience is measurement discipline. Bore tolerance, key size or shrink-disc grade and insertion depth must be stated to the millimetre, so a mating shaft sketch belongs with every first order.
Mapping the Marking to the Hardware
| M | Industrial multi-stage gear unit family |
| P | Parallel helical stages without a bevel set |
| V | Vertical housing, output at the underside |
| H | Hollow machined bore through the output |
| F | Foot pads and top flange for hanging the unit |
| 30 | Frame size, compact end of the upright range |
Every letter ends as a line on the order confirmation: bore and fit, clamping element grade, seal material, flange drilling, breather position. Quoting the duty together with the shaft drawing is what produces a unit that drops onto the existing column without rework.
Seals and the Medium Above Them
The output seal faces the process medium directly, and on small vessels that medium is often the aggressive one - brine, dye liquor, reagent solutions or washdown zones. Stating the chemistry at order stage lets the factory fit the right seal grade instead of a general-purpose one, and the lower bearing benefits from the same declaration because its load depends on how the far end of the shaft is guided. A steady bearing at the vessel floor, where the layout allows one, visibly extends both lives.
Machine groups this unit is specified into: Direct-drive stirrers on fermentation seed tanks Vertical turbine pumps on shallow intake bays Rake mechanisms on circular grit chambers Emulsifier shafts in cosmetic batch kettles Sludge hopper screws beneath settling lanes Cooling tower low-cell fans on compact frames Dye bath paddle drives in textile mills Reagent makeup agitators in reagent dosing rooms
Installation on a Working Vessel
Measure the vessel boss before ordering: bolt circle, face flatness and any pedestal height belong on the drawing alongside the shaft data. On site, support the unit until the fixing bolts are tight, raise the shaft through the bore to the marked insertion depth, set end float, then close the key or shrink disc to the recorded torque. Fill to the plate quantity and read the level at rest before the first start.
Hand-rotate the train once - binding at one angle means the shaft is running out, not that the gearbox is faulty - then run unloaded briefly and log oil temperature and any seal weep as the site baseline. Those two numbers anchor every later inspection on the vessel.
Records That Pay Back Later
Keep the dimensioned drawing and seal grade with the vessel file so that an identical spare can be quoted years later from a nameplate photo. For sites running several identical kettles or basins, one drawing plus one seal kit reference usually separates a same-day changeover from a waiting week. That is the quiet argument for the hollow-shaft build wherever the process shaft must come out for cleaning.
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: Typical duty point
Consider a typical duty for this frame: the driven shaft has to run at a fraction of motor speed. 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 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
Steel mill transfer car
A rolling mill drives its slab transfer cars with industrial gear units mounted on torque arms. Reversing duty every few minutes is handled without complaint, and the hollow-shaft connection keeps the wheel axles free of couplings.
Rotary dryer drive
A minerals processor powers a rotary dryer with a large foot-mounted gear unit. Slow rotation with high torque is the natural duty band, and the housing stays within its temperature limits without auxiliary cooling.
Technical Questions, Answered
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.
What are the delivery lead times and shipping terms?
Standard lead time is 5-10 weeks ex-works, with popular ratios often available sooner. We quote EXW, FOB NINGBO / SHANGHAI or CIF, and urgent units can be air-freighted within 72 hours of payment.
![industrial helical gear reducer application fields]()
Common application areas for right-angle industrial helical drives.
Size It, Quote It, Ship It
One minute, one model. 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.
Give us the driven machine, the required output speed and the daily running hours, and we return a confirmed model number with torque margin and a firm price - no obligation, no charge for the selection work. Looking for a gear motor for car wash system? Tell us the duty point and we will confirm the model in writing.
