The M3RHT70 bevel torque arm gear reducer takes the size 70 industrial housing and arranges it for direct shaft mounting: spiral-bevel input, two helical stages, and a hollow output bore that rides the driven shaft while the torque arm ties the reaction back to the machine frame. It is the frame that plant engineers reach for when a conveyor or drum drive must be fitted without foundations yet still carry serious continuous torque.
Size 70 Torque-Arm Power in a Bevel-Helical Train
Above size 60 the shaft and bearing sections grow, and the 70 frame is where shaft-mounted drives begin to handle main-line duties rather than auxiliary ones: head pulleys on long plant conveyors, apron feeders under screens, thickener rake centres. The three-stage train keeps sliding contact out of the power path, so losses stay low even at the deep ratios these slow shafts demand, and the housing splits horizontally for inspection without disturbing the shaft alignment the torque arm already guarantees.
Reading M3RHT70 from the Nameplate
| M3 | Industrial gear unit family, three geared stages |
| R | Bevel-helical right-angle input (P marks the all-parallel build) |
| H | Hollow low-speed shaft bored for a key (S would be a solid output stub) |
| T | Torque-arm reaction, no foundation needed (F would be a foot mount) |
| 70 | Frame size 70 within the horizontal band 50 to 90 |
Because the notation is compositional, the same size 70 geometry can be re-lettered to a solid foot-mounted build for drive points that do use couplings, and the drawing office can quote either interface from one outline-drawing family.
Drivetrain duties this frame answers to:
- Overland and stockyard conveyor head pulleys
- Rotary airlocks and vane feeders under hoppers and silos
- Travel and slew drives on gantry and portal machines
- Thickener and clarifier rake centres in mineral plants
- Apron feeders under crushers and screens
- Cane carriers and diffuser chains in sugar mills
Heavy Duties on a Shaft-Mounted Frame
Typical installations put the unit straight onto a head pulley shaft, a rake centre column or a drum shaft with its own plummer blocks. Fitting needs no bedplate concrete, no laser-aligned coupling and no shimming cycle; maintenance teams remove the unit by pulling it off the shaft, which shortens gearbox exchanges to hours. WGT reviews overhung load, service factor and starting duty against the installation drawing before a selection is confirmed.
Enquiry to Dispatch
The catalogue and size 70 outline drawing are supplied as PDF downloads for interface verification - bore, keyway, torque-arm pin and motor flange. Provide the driven machine, motor power and speed, required output speed and the shift profile, and the rated-torque check completes the selection; a written quotation follows. Every unit is run at the factory, packed in an export wooden crate and covered by a one-year warranty.
How Customers Use This Unit
Glass batch charger
A float-glass line drives its batch charger with units. Abrasive raw material demands a robust drive, and the case-hardened gears show minimal wear after years of continuous operation.
Battery slurry mixer
A battery materials plant uses reducers on slurry mixers. High shear loads are absorbed by the 42CrMo shafts, and the 94-96% efficiency keeps motor sizing and running cost down.
What Engineers Ask Us
What is the difference between foot and torque-arm mounting?
Foot mounting bolts the housing to a foundation and suits most fixed installations. A torque-arm lets the housing swing on the driven shaft, so no base frame is needed - common on shaft-mounted conveyors where the reaction rod absorbs the torque.
Should I choose a solid or hollow output shaft?
A solid shaft with a keyed coupling is the flexible, conventional choice. A hollow shaft takes the driven shaft directly with a key or shrink disc, removing one coupling and one alignment step; it is preferred where space or alignment access is limited.
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: Stockyard conveyor head pulley drive
Take a 110 kW motor at 1485 rpm driving a stacker conveyor head shaft at 14 rpm. The ratio follows directly: 1485 / 14 = 106, so the three-stage band with a raised service factor covers the pulley torque. In this case the shaft-mounted build rides the head shaft directly, so the drive relocates with the stacker as the pile moves. 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.
From Duty Point to Delivery in One Working Day
Stop guessing the ratio. 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.
Tell us what the machine does and how hard it works; we calculate the ratio, apply the service factor and send back the drawing and quotation within one working day, including sea-freight and air-freight options. Looking for a speed reducer for cement plant? Tell us the duty point and we will confirm the model in writing.
