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What is a Gearbox Motor?

Jiaming CaiJune 27, 2023

A gearbox motor, also known as a gear motor, is a high-torque low-speed motor that combines a gearbox with an electric motor. The combination of motor and gearbox can provide customers with thousands of ratios of motor output torque and speed. Therefore, gearbox motors are mainly used in high-torque, low-speed precision transmission fields.

Gearboxes
Small DC Brushed Motor
electric motors

Types of Gearbox Motor

A gearbox motor is a special type of electric motor that produces high torque while maintaining low horsepower (or low speed). The function of the gearbox is to increase the output torque of the gearbox motor by reducing the speed of the output shaft end of the motor.

Gearbox motors come in a variety of types, each with their unique advantages, reduction structure, and applications. These include, but are not limited to:

Squard Spur gearbox motor diagram
Squard Spur gearbox motor diagram

What’s Inside a Gearbox?

The gearbox is an integral mechanical structure based on the gear transmission system. Gearboxes include but are not limited to: Gearbox gears, Gearbox shaft, Gear Lubricating oil, Gearbox shafts, Spacers, Gearbox bearings and Gearbox housings.

Component NameFunction Description
GearsTransmit power and adjust speed ratio
Gearbox ShaftConnects gears and transmits torque
Lubricating OilReduces friction, minimizes wear, and extends lifespan
Gearbox HousingProtects internal components and provides structural support
SpacersAdjust clearance and reduce wear
BearingsSupport rotating parts and reduce friction

1.Gearbox Gears

The gears in micro gearboxes are mainly low modulus, high precision gears. From the analysis of gear materials, the mainstream micro gear materials on the market are mainly composed of three types – plasticiron alloysteel alloy.

plastic gears
plastic gears
powder metallurgy gears
Iron gears
hobbed gears
Steel gears
Material TypeGear StrengthSelf-LubricationTemperature ResistanceCorrosion ResistanceNoise LevelProcessing Method
Plastic Gears▮▯▯▯▯ (▮▮▮▮▯ ▮▮▯▯▯ ▮▮▮▮▮ ▮▮▮▮▯ Injection Molding
Iron Gears▮▮▮▯▯ ▮▯▯▯▯ ▮▮▮▯▯ ▮▮▯▯▯ Oxidation▮▮▯▯▯ Powder Metallurgy
Steel Gears▮▮▮▮▮ ▮▯▯▯▯ ▮▮▮▮▮ ▮▮▯▯▯ Oxidation▮▮▮▯▯ Hobbing

2.Gearbox Shaft

Gearbox shaft is a critical component of the gearbox motor as it connects the motor to the application or device it is powering, enabling the transmission of mechanical energy.

Pin shaft
Pin shaft
Round shaft
Round shaft
Thread shaft

In the gearbox motor, the output shaft is responsible for outputting torque, bearing load, and connecting application equipment. Therefore, the output shaft is the key connection accessory in the micro gearbox.

Related Article: Micro Gearbox selection guide – How to choose gearbox shaft

3.Gearbox Bearing

Bearings are critical components in a gearbox motor. Bearings have the following main functions

BenefitDescription
Friction ReductionMinimizes friction for smooth movement.
Load SupportSupports radial and axial loads.
Efficient RotationEnables free shaft rotation.
Alignment MaintenanceKeeps the shaft aligned, preventing damage.
Heat ManagementHelps dissipate heat, prolonging life.
Vibration ReductionReduces vibrations for quieter operation.
Ball Bearing
Sliding Bearing

4.Gear Lubrication

The lubrication system used inside the gearbox is mainly lubricating oil, which can reduce the friction in the gear transmission system. Effectively protect the life of the gears and reduce the noise emitted by the gear box during transmission.

PropertyMineral OilSynthetic Oil (PAO)Synthetic Oil (Ester)
Viscosity Grade (ISO VG)ISO VG 68ISO VG 68ISO VG 68
Viscosity Index (VI)95160180
Thermal Stability– Flash Point: 200°C– Flash Point: 240°C– Flash Point: 250°C
– Oxidation Life: 1000 hours– Oxidation Life: 3000 hours– Oxidation Life: 3500 hours
Low-Temperature Fluidity– Pour Point: -15°C– Pour Point: -45°C– Pour Point: -48°C
– Cold Start Torque (-20°C): >20 N·m– Cold Start Torque (-30°C): <10 N·m– Cold Start Torque (-40°C): <8 N·m

5.Gearbox Casing

The gearbox housing is the housing used to house all the accessories of the gearbox. The main function of the casing is to provide mechanical support for the components that are driven in it, and to provide protection for these internal components from external interference.


MaterialAdvantagesDisadvantages
Aluminum Alloy✅ Lightweight
✅ Corrosion Resistance
✅ Heat Dissipation
✅ Strength
❌ Higher Cost
❌ Wear
Zinc Alloy✅ High Strength
✅ Precision
❌ Heavier
❌ Corrosion
ABS Plastic✅ Cost-Effective
✅ Lightweight
✅ Design Flexibility
❌ Heat Resistance
❌ Strength

Choose the housing material based on specific application needs (e.g., heat dissipation, load capacity, budget)

Related Article – What is a Gearbox Housing (Gearbox Casing)

Application of Gearbox Motor

Micro gear motors are suitable for most low speed, high torque fields. We can see gearbox motors in various automation fields.

How to Select the Right Motor for Your Gearbox

Selecting the right motor to pair with your gearbox is critical for achieving optimal efficiency, performance, and reliability. An incorrect match can lead to system inefficiencies, premature wear, or even failure. Follow these steps to ensure a proper selection:


Step 1: Define Your Requirements

Before selecting a motor, clearly define the operational needs of your application:

  • Power: Determine the required power output (in watts or horsepower).
  • Speed: Identify the desired operating speed (RPM).
  • Torque: Calculate the torque needed to drive the load.
  • Environmental Factors: Consider temperature, humidity, and exposure to dust or chemicals.
  • Duty Cycle: Evaluate how often and how long the system will operate (continuous or intermittent).
  • Install Size: Consider the size of the motor from the perspective of mounting dimensions.

Step 2: Choose the Right Motor Types

Select a motor type that aligns with your application’s requirements:

  • DC Brush Motor:
  • BLDC Motor (Brushless DC Motor):
  • Outrunner BLDC Motor
  • AC Motor
  • Stepper Motor
  • Servo Motor
DC Brush Motor
DC Brush Motor
BLDC Motor

Step 3: Select the Gearbox

Match your motor with a gearbox that complements its performance:

  • Spur Gearbox:
  • Planetary Gearbox:
  • Worm Gearbox:
  • Harmonic Gearbox
  • Cycloid gearbox
Spur Gearbox
Worm Gearbox

Step 4: Calculate Gear Ratios

Ensure the gear ratio aligns with your system’s requirements:

  • Use the formula: Gear Ratio = Motor Speed ÷ Output Speed.
  • A higher gear ratio increases torque but reduces speed, while a lower ratio does the opposite.

Step 5: Test and Validate

After pairing the motor and gearbox, conduct thorough testing to validate performance:

  • Measure output speed, torque, and efficiency under real-world conditions.
  • Adjust the system as needed to optimize performance and reliability.

For a comprehensive guide on gear motor selection, check out our Gear Motor Selection Guide.

Conclusion

Understanding the gearbox motor, its components, its types, and how to match it with a motor is integral to leveraging its capabilities. At Doncen Motor, we excel in providing a wide range of high-quality gearboxes and motors that can meet various applications. Explore our catalog to find the perfect motor and gearbox for your needs today!

Thanks SGMADA for the technical guide for this article.