Can I use a 0.75 kW motor with an NMRV040 gearbox?

A 0.75 kW motor should not be paired with an NMRV040 without a detailed capacity check. Confirm the required output torque, ratio, operating hours and thermal limits; a larger gearbox may be more suitable.

Does reduction ratio affect NMRV gearbox motor power selection?

Yes. Ratio changes output speed, torque multiplication, efficiency and allowable input power. The same frame may require a different motor-power selection at a different ratio.

Can an NMRV gearbox be supplied without a motor?

Yes. NMRV worm gearboxes can be supplied separately or as a matched geared-motor assembly after motor-mounting and application requirements are confirmed.

What Motor Power Is Suitable for an NMRV Gearbox?

Q: Is an NMRV050 gearbox suitable for a 0.37 kW motor?

An NMRV050 with a 0.37 kW four-pole motor is a common combination to consider for light industrial equipment, provided that the selected ratio and operating conditions are within the gearbox ratings.

Published November 2, 2026 · Reviewed by SMK Transmission

Quick answer: Suitable motor power for an NMRV worm gearbox depends on the gearbox size, reduction ratio, required output torque and operating conditions. NMRV040 units are often considered with 0.18–0.37 kW motors, while NMRV050 units may be paired with 0.37–0.55 kW motors. These are common combination examples only: confirm the selected gearbox's rated torque, allowable input power and thermal capacity before finalizing a motor.

SMK NMRV worm gearboxes prepared in the production area — SMK NMRV worm gearbox units prepared in the production area. Final motor matching is confirmed against the selected configuration.

DISCUSS YOUR APPLICATION →CALCULATE RATIO & TORQUE

Common Motor-Power Examples by NMRV Gearbox Size

Customers often ask whether a specific NMRV gearbox can be used with a 0.37 kW, 0.75 kW or 1.5 kW motor. The table below is for preliminary comparison only. It is not an approved rating for every ratio, mounting position or operating condition.

NMRV gearbox	Motor-power examples
NMRV030	0.06 / 0.09 / 0.12 kW
NMRV040	0.12 / 0.18 / 0.25 / 0.37 kW
NMRV050	0.18 / 0.25 / 0.37 / 0.55 kW
NMRV063	0.37 / 0.55 / 0.75 / 1.1 kW
NMRV075	0.55 / 0.75 / 1.1 / 1.5 kW
NMRV090	0.75 / 1.1 / 1.5 / 2.2 kW
NMRV110	1.5 / 2.2 / 3.0 kW
NMRV130	2.2 / 3.0 / 4.0 kW
NMRV150	3.0 / 4.0 / 5.5 kW

Selection limitation: A motor suitable at one reduction ratio may not be suitable at another ratio for the same frame size. Use the table to start the conversation, then verify the exact performance data and application duty.

Can a 0.75 kW Motor Be Used with an NMRV040?

We do not recommend selecting an NMRV040 with a 0.75 kW motor without a detailed capacity check. A larger motor does not automatically increase the gearbox's allowable output torque. If the transmitted load exceeds the rating, excessive temperature rise, accelerated wear or mechanical damage can result.

Before considering this combination, confirm the required output torque, reduction ratio, operating hours and starts. A larger gearbox may be more suitable for the application.

Is an NMRV050 Suitable for a 0.37 kW Motor?

An NMRV050 gearbox with a 0.37 kW four-pole motor is a common combination to consider for light industrial equipment, provided that the selected ratio and operating conditions are within the gearbox ratings.

Parameter	Example specification
Gearbox	NMRV050
Motor power	0.37 kW
Motor speed	Approximately 1400 rpm
Reduction ratio	30:1
Estimated output speed	Approximately 46.7 rpm
Application	Light-duty conveyor

Output torque and gearbox service factor must still be checked before confirming suitability. For ratio-specific RV-series data, see the RV25–RV150 motor power selection reference.

Why Does Reduction Ratio Affect Motor-Power Selection?

Reduction ratio affects output speed, torque multiplication, gearbox efficiency and allowable input power. With a motor input speed of approximately 1400 rpm, estimated output speed is:

Output speed = motor speed ÷ reduction ratio

For example, 1400 rpm ÷ 30 = approximately 46.7 rpm. A higher ratio reduces output speed, but does not by itself mean that a larger motor is suitable. Efficiency, heat generation and mechanical capacity must also be reviewed. Use the ratio and torque calculator for a preliminary input check.

What SMK Checks Before Matching a Motor and Gearbox

Required output speed: used to determine a suitable ratio.
Required running and peak output torque: the gearbox must meet the load without exceeding its rating.
Motor voltage and frequency: such as 220 V, 380 V, 400 V, 50 Hz or 60 Hz according to the application.
Working conditions: continuous duty, frequent starts and stops, shock load and ambient conditions affect selection.
Motor mounting dimensions: frame size, shaft diameter and B5 or B14 flange must be mechanically compatible.

If you already have a motor, send its nameplate and dimensional drawing. For frame-size comparison, see the NMRV gearbox size guide; for an NMRV040 replacement, see the NMRV040 dimensions and selection guide.

Can SMK Supply an NMRV Gearbox with a Motor?

Yes. SMK supplies NMRV/RV worm gearboxes and complete worm geared-motor assemblies. Options can include compatible single-phase or three-phase AC motors, different ratios, hollow or solid output arrangements and IEC motor mounting flanges. A gearbox can also be supplied separately when the buyer already has a suitable motor. Learn more about the worm gear reducer range and the worm gear motor assemblies.

Frequently Asked Questions

What motor power is suitable for an NMRV063 gearbox?

Motor powers such as 0.37 kW, 0.55 kW, 0.75 kW and 1.1 kW may be considered depending on the reduction ratio and application. Verify the final combination using the gearbox performance ratings.

Can I use a 1.5 kW motor with an NMRV090 gearbox?

This can be considered for some applications, but reduction ratio, output torque, duty cycle and thermal capacity must be checked first.

Can I replace an existing motor with a higher-power motor?

Not always. A higher-power motor can exceed the gearbox's allowable torque or input power. Check the existing gearbox model and ratio before replacing the motor.

Can I use a single-phase motor with an NMRV gearbox?

Yes, with a compatible motor. Confirm frame size, mounting flange, shaft dimensions and operating requirements.