NMRV Gearboxes (often referred to simply as NMRV gearboxes or NMRV units) are a type of gearbox with a rectangular design, widely applied in industry due to their high durability and stable operating efficiency. When combined with an electric motor, these NMRV Gearboxes form geared motors, effectively reducing speed and increasing torque, while providing a compact and easy-to-install transmission solution for various types of machinery and equipment.

Structure of NMRV Gearbox

NMRV Gearboxes (also known as NMRV worm gearboxes) are a popular series of gearboxes due to their compact structure, flexible installation, and simple maintenance. Below is a full description of the components and structural characteristics of NMRV:

Worm and Worm Wheel Assembly

• Worm shaft (worm): Typically made of hardened alloy steel, precision machined to ensure smooth meshing and good wear resistance.
• Worm wheel (wormwheel): Usually manufactured from bronze or bronze alloy to reduce friction and increase lifespan when meshing with the worm shaft. The steel-on-bronze combination optimizes the friction coefficient and torque transmission capability.

Housing

• Small sizes (30, 40, 50, 63, 75, 90): The housing is typically made of die-cast aluminum, offering advantages of being lightweight, excellent heat dissipation, and convenient for overhead or mobile frame installation.
• Large sizes (110, 130, 150): The housing is reinforced with cast iron, enhancing durability, rigidity, and load-bearing capacity for heavy industrial applications.
• The housing often features cooling fins, an inspection cover, an oil filler plug, flanges, and mounting bolt holes for easy installation and maintenance.

Sizes and Standards

• NMRV sizes are determined by the center distance between the input and output shafts.
• Common sizes: 30, 40, 50, 63, 75, 90, 110, 130, 150 - each size corresponds to a different power and torque range, suitable for motors from 0.18 kW to 7.5 kW depending on the type.

Input - Output Shafts and Motor Connection

• Input shaft: Often a hollow shaft or a solid shaft with a keyway, connected to the motor via a standard flange or coupling.
• Output shaft: Can be a solid shaft or a hollow shaft with a keyway, adaptable to various applications (pulleys, gears, couplings).
• NMRV gearboxes typically have a standard flange for easy installation of IEC/standard motors from 0.18 kW to 3 kW (aluminum housing) or 4-7.5 kW (cast iron housing).

Bearings and Shaft Support System

• Quality ball bearings are used to withstand radial and axial loads, ensuring smooth shaft operation, reduced vibration, and extended lifespan.
• Bearings are rationally arranged to ensure concentricity between the worm shaft and worm wheel, reducing wear and mechanical losses.

Seals, Gaskets, and Oil Management

• Equipped with oil seals and anti-leak rubber gaskets, retaining lubricant and preventing dust and water ingress.
• The gearbox has an oil filler plug, a drain plug, and an inspection cover, facilitating oil changes, level checks, and lubrication status monitoring.

Lubrication System

• NMRV gearboxes use specialized oil or grease for worm gearboxes to reduce friction and dissipate heat.
• Some larger models feature a circulating lubrication system or oil pump locations for heavy-duty/continuous operation.

Operating Principle of NMRV Gearbox

When the electric motor rotates, motion is transmitted to the worm shaft of the NMRV Gearbox. This worm shaft acts as an “endless screw,” converting the high-speed rotational motion of the motor into slower rotational motion in the worm wheel.

During this process, the worm teeth slide along the grooves of the worm wheel, creating a sliding friction motion rather than direct meshing like cylindrical or conical gears. This characteristic helps the NMRV gearbox operate smoothly, effectively reducing shock and vibration, although there may be some energy loss due to high friction.

As the worm wheel rotates, torque is amplified and transmitted to the output shaft, enabling heavy-duty equipment to operate more stably and powerfully even with a small motor output.

Classification of NMRV Gearboxes

Classification by Housing Material

• NMRV Gearboxes with aluminum housing: Include smaller sizes such as NMRV 30, 40, 50, 63, 75, 90.
• NMRV Gearboxes with cast iron housing: Include larger sizes such as NMRV 110, 130, 150.

Classification by Reduction Stages

NMRV 1-Stage Gearbox: Features one worm shaft and one worm wheel. Offers gear ratios from 1:10 to 1:60, sufficient for systems requiring moderate speed reduction.

NMRV 2-Stage Gearbox (combining NMRV + NMRV or NMRV + Helical): Higher gear ratios, up to 1:100 - 1:3600, suitable for applications requiring high speed reduction and large torque.

Classification by Output Shaft Type

• Solid output shaft: Is the most common type, a solid shaft integral with the worm wheel, directly transmitting power to gears or couplings.
• Hollow output shaft: Allows direct mounting onto the machine shaft or load equipment, saving space and reducing shaft misalignment.
• Right-angle output shaft: Designed for applications requiring a 90° change in rotation direction, providing flexibility in machine layout design.

Classification by Mounting Method

• Foot-mounted (B3): Used for machines placed on the floor, secured by bolts.
• Flange-mounted (B5, B14): Directly mounted to electric motors, saving space and easy to assemble/disassemble.
• Shaft-mounted (hanging type): Applied to conveyor systems or equipment with suspended shafts, saving installation space.

Advantages of NMRV Gearboxes

Compact Design, High Aesthetics

• NMRV Gearboxes have a square box shape, compact size, and light weight, making them easy to install in confined spaces.
• Sizes from 30 to 150 offer flexible solutions for various machinery, from mini conveyors to large industrial equipment.
• The aluminum or cast iron housing surfaces are precisely machined and electrostatic powder coated for corrosion resistance, enhancing both durability and aesthetic appeal.

High Transmission Efficiency, Smooth Operation

• The precisely designed worm and worm wheel mechanism helps reduce vibration and noise during operation.
• Transmission efficiency can reach 85 - 95%, ensuring energy savings and extending the lifespan of the electric motor.
• Smooth rotational motion is suitable for systems requiring high stability and continuous operation.

High Load Capacity and Torque

• NMRV gearboxes offer diverse gear ratios (from 1:7 to 1:3600), allowing flexible speed adjustment according to specific needs.
• Large output torque enables equipment to handle heavy loads well, suitable for industrial applications such as mixers, presses, hoists, and heavy-duty conveyors.

Easy Installation and Maintenance

• International standard design, compatible with most types of electric motors, servo motors, or stepper motors.
• Can be installed in various positions: horizontal, vertical, or suspended, depending on the layout space of the production line.
• Easy to maintain; regular oil changes and inspection of oil seals ensure stable operation for extended periods.

High Durability, Long Lifespan

• Worm wheels are made from steel-bronze alloy or brass, offering good wear resistance and anti-deformation capabilities.
• High-quality bearings and oil seals help minimize friction and oil leakage.
• The housing is made of integrated die-cast aluminum alloy or cast iron, providing rapid heat dissipation and ensuring continuous operation in harsh environments.

Diverse Gear Ratios - Flexible Applications

• Can combine two NMRV gearboxes or an NMRV gearbox with a parallel shaft gearbox to achieve higher gear ratios.
• Easily connects to electric motors with power from 0.18kW to 7.5kW or more, suitable for all production needs.

Reasonable Price - High Economic Efficiency

• Compared to similar gearbox series (such as Cycloidal Gearboxes or HB-Series Helical Gearboxes), NMRV Gearboxes have a lower price but still offer excellent performance.
• Low maintenance costs and easy component replacement help businesses significantly save on operating expenses.

Applications of NMRV Gearboxes

Applications in Conveyor Systems

• Used to adjust the transmission speed of goods conveyors, food conveyors, and product sorting conveyors.
• Helps ensure stable movement speed, save energy, and reduce motor wear.
• Notably, NMRV Gearboxes can operate continuously in high humidity and dusty environments.

Applications in Packaging Machines, Filling Machines

• In the food, beverage, and pharmaceutical industries, NMRV gearboxes ensure smooth, precise, and safe operation.
• Easily integrated with servo motors to achieve high accuracy in dosing, packaging, and filling.

Applications in Mixers, Grinders, Presses

• Helps reduce rotational speed and increase torque, ensuring even mixing of materials and stable operation.
• Suitable for industries producing plastics, rubber, cement, animal feed, or ceramics.

Applications in Lifting Systems, Inclined Conveyors

• When combined with an electric motor, NMRV Gearboxes help control the lifting and lowering speed of loads safely.
• Used in cargo lifts, mini crane systems, escalators, and steep inclined conveyors.

Applications in Robotics and Automation Lines

• NMRV gearboxes offer high precision and stability, suitable for picking robots, robotic arms, or small-sized CNC machines.
• Their compact design allows direct installation into the robot’s motion mechanism without requiring much space.

Applications in Water Treatment and Environmental Industries

• Used in sludge agitators, chemical mixing tanks, air blowers, and industrial pumps.
• NMRV gearboxes are capable of performing well in humid environments, tolerating heat and slight vibrations.

Applications in Agriculture and Animal Husbandry

• Installed in lawn mowers, pellet mills, mixing machines, and agricultural dryers.
• Increased torque enables equipment to work more powerfully and stably, saving electricity.

Applications in Textile and Wood Processing Industries

• In textile machines, fabric winding machines, saws, and sanding machines, NMRV gearboxes help flexibly adjust the spindle speed.
• Ensures uniformity, precision, and surface quality of products.

Applications in Parking Lots, Automatic Doors, and Sliding Gate Systems

• With their smooth transmission capability, NMRV gearboxes are often used for rolling door motors, automatic sliding gates, and car lifting systems.
• Ensures stable equipment operation, limiting vibration and noise.

Applications in Light Industry and Civil Use

• Many household or small industrial appliances such as industrial washing machines, ovens, and mini conveyors use this type of gearbox.
• Helps optimize efficiency and extend the lifespan of electric motors.

Latest NMRV Gearbox Price List 04/2026 at Thanh Thai Motor

Video Price Quote for Latest NMRV Gearbox 04/2026 at Thanh Thai Motor