Worm Gear Reducer

The NMRV Worm Gear Reducer is a right-angle speed reducer that transfers power between perpendicular shafts while reducing speed and multiplying torque. Available in 10 center distances from 025 to 150, with die-cast aluminum alloy housings for sizes 025–090 and G200 grey cast iron for sizes 110–150. Each unit uses a bronze CuSn12Ni2 worm wheel and a 20Cr carbonized and ground worm shaft for high wear resistance, quiet running and long service life.

If you are sourcing NMRV worm gear reducers for OEM assembly, MRO replacement or dealer stock, this page gives you the size range, material construction, performance data, mounting options and the exact information we need to quote you accurately.

How an NMRV Worm Gear Reducer Works

The NMRV worm gear reducer uses a worm shaft (a helical screw) that meshes with a bronze worm wheel. The worm is driven by an electric motor through a bell housing or input shaft, and the worm wheel rotates at a reduced speed with increased torque. The 90-degree shaft arrangement allows the output to drive a perpendicular load — ideal for conveyor pulleys, packaging rollers and mixing shafts.

The hollow output shaft accepts a keyed shaft directly through the reducer, saving the need for a separate coupling and bearing support. Sizes 025–090 use a die-cast aluminum alloy housing that resists rust and dissipates heat efficiently. Sizes 110–150 use G200 grey cast iron for higher rigidity under heavy radial and axial loads.

Center Distance & Ratio Selection Guide

Choose the center distance based on required output torque and radial load; choose the ratio based on required output speed. Below is the standard ratio range for each size. Double-stage combinations are available for ratios above 100:1.

Need a ratio above 100:1? Double-stage combinations are available: 25/30, 25/40, 30/40, 30/50, 30/63, 40/75, 40/90, 50/110, 63/130 and 63/150. Send your required output speed and torque for a confirmed selection.

Mounting Options & Output Configurations

Where NMRV Worm Gear Reducers Are Used

• Conveyor systems — belt and roller conveyors in packaging, food processing and material handling lines.
• Packaging machinery — filling, capping, labelling and carton-sealing equipment requiring compact right-angle drives.
• Food and beverage processing — mixers, agitators and rotary fillers where washdown and corrosion resistance matter.
• Agricultural machinery — grain augers, feed mixers and manure spreaders driven from a tractor PTO or electric motor.
• HVAC and ventilation — cooling tower fans and air handling units where quiet operation is required.
• OEM equipment — machine builders needing a repeatable, pre-engineered speed reduction solution.
• MRO replacement — replacing worn NMRV units on existing production equipment.

Quality Control You Can Audit

Ordering & Supply Information

Installation & Maintenance Tips

• Check oil level before commissioning. Aluminum units are supplied with synthetic oil; cast iron units should be filled to the oil level plug.
• The universal mounting position means the unit can be installed in any orientation without changing the oil quantity.
• Align the input motor shaft with the reducer input before tightening the coupling. Misalignment causes noise and premature seal wear.
• For hollow shaft mounting, ensure the driven shaft is clean and keyed correctly, and use the torque arm to prevent rotation.
• Change the oil after the first 500 hours of operation, then every 5,000 hours or annually, whichever comes first.
• Inspect oil seals for weeping at each service interval. Replace worn seals early to prevent oil loss and contamination.
• Keep the breather plug clean and unobstructed to prevent pressure build-up inside the gearbox.

FAQ — NMRV Worm Gear Reducer