Gear Motor Selection and Matching Guide

In many industrial applications, the failure of a gear motor is not caused by poor quality, but by incorrect selection and matching. If the motor does not truly match your equipment’s load, speed, and duty cycle, problems such as noise, overheating, short life, or insufficient torque will appear quickly.

This article explains how to correctly select and match a gear motor, using practical engineering logic that you can directly apply to your project.

1. Understand the Real Application Requirements

Gear motor selection must always start from your equipment, not from a motor catalog.

You should clearly define:

• Required output torque (N.m)
  Include starting torque, peak load, and possible shock load.

• Required output speed (RPM)
  This is the working speed under load, not no-load speed.

• Load characteristics
  Constant load, variable load, impact load, or frequent start-stop.

• Duty cycle
  Continuous operation (S1) or intermittent operation (S2 / S3).

Key point:
Most selection errors happen because only rated power is considered, while starting torque and real load are ignored.

2. Calculate the Correct Gear Ratio

The gear ratio determines whether the motor can reach the required speed and torque efficiently.

Basic formula:Gear Ratio=Input SpeedOutput Speed

• AGV, mobile robots, drive wheels: 10–50

• Robot joints, lifting systems: 30–100

• Automatic doors, conveyors: 20–60

A higher gear ratio increases torque but may reduce efficiency and increase noise. The ratio must be balanced, not maximized.

3. Select the Right Motor Type

Different motor types suit different performance and cost requirements.

• Brushless DC gear motor

• Low noise and vibration

• High efficiency

• Ideal for AGV, robots, medical and automation equipment

• The product sizes shown in the figure are 57mm, 86mm, 130mm, and 126mm BLDC Geared Motors,they are ultra-high performance and are suitable for 24V/48V/220V/310DC equal voltage mode,35W-3000W,0.4-300N.m.The gearbox has high efficiency and is suitable for industrial, medical and other precision fields.
  

• Brushed DC gear motor

• Simple control

• Lower cost

• Suitable for cost-sensitive industrial equipment

• The above shows the best-selling models of BG: 52mm, 63mm, and 110mm DC brushed geared motors, as long as they are suitable for 12-220VDC, 40W-600W application equipment.If you have other data matches and needs, we have a wider range of motor options

• Worm gear motor

• High reduction ratio

• Self-locking function

• Suitable for lifting, positioning, and safety-related applications

• The worm gear worm motor has a wide data range, suitable for 3W-3000W, 12V/48V/110V/310VDC&110V-230VAC, 0.5-300N.m.The lead wire, shaft, protection level, etc. can be customized according to the needs, suitable for most precision instruments on the market

At BG Motor, we combine DC brushed motors, BLDC motors, and planetary or worm gearboxes to match different application needs.

4. Check Torque Safety Margin and Gearbox Capacity

To ensure long service life, the gear motor must never run at its limit for long periods.

Recommended rules:

• Actual working torque ≤ 70–80% of rated output torque

• Starting torque and stall torque must not exceed gearbox limits

• Verify gearbox load capacity and bearing life

Running continuously at maximum torque is one of the main causes of early gear motor failure.

5. Consider Noise, Vibration, and Precision

For modern equipment, especially robots and medical devices, mechanical performance is critical.

You should evaluate:

• Gear precision and backlash

• Noise level and vibration

• Gear material and heat treatment

• Alignment between motor shaft and gearbox

High-precision planetary gear motors provide low backlash, low noise, and stable output, which is why they are widely used in high-end equipment.

6. Confirm Installation and Mechanical Interface

Even a well-selected gear motor will fail if installation is incorrect.

Check carefully:

• Motor diameter and length limits

• Output shaft type (D-shaft, round shaft, spline, hollow shaft)

• Mounting hole position and tolerance

• Axial and radial load on the output shaft

BG Motor supports custom shafts, mounting patterns, and housing designs to match your equipment perfectly.

7. Standard Model or Customized Solution?

Standard gear motors are suitable for general applications, but many projects require customization.

Customization options include:

• Gear ratio

• Output shaft structure

• Gear material and accuracy

• Motor winding, voltage, speed, and torque curve

• Encoder, brake, or driver integration

A customized gear motor reduces system risk, improves performance, and shortens development time.

Correct gear motor selection and matching is a system-level engineering task, not a simple model choice.

If you provide:

• Application scenario

• Required speed and torque

• Duty cycle and load type

• Installation constraints

BG Motor can help you complete gear motor selection, calculation, and verification, ensuring stable performance, long life, and low noise in real operation.

Choosing the right gear motor once is far better than replacing the wrong one many times.