Speed Reducer for Electric Motors


High-grade industrial machinery works on various load rates; therefore, the usual electric motors are not capable of controlling high loads. The motor manufacturer has introduced a speed reducer for electric motors to maximize the operational capacity of the machinery. The electric motor gearbox plays a significant role in increasing or decreasing the efficiency of the electric motor. Electric motors with gear reducers are widely used in the industries for delivering sufficient speed and torque to the equipment effectively. 

Speed Reducer for Electric Motors

Figure 1: speed reducer for electric motors

Xinnuo Motor is a qualified electric motor manufacturer in China that supplies highly precise and reliable gear reduction motors internationally.  In this article, we will discuss different types of gear motors, their uses, and their advantages. We will also go through some of the important factors to consider before buying a gear reducer for the electric motor. 

Some common types of gearbox speed reducers for electric motors

An electric motor with a gear reducer reduces the speed and increases torque according to the requirement of machinery. Some of the most common types of the electric motor gearbox are as follows;

Worm gearbox:

The fundamental structure of the worm gearbox looks like a spiral coiled around the shaft gear or wheel. These gearboxes interact via sliding motion with the help of lubricated teeth. Thus, the worm-like gear motors produce low sound and vibration than other electric motor gearboxes. Worm gears are high-power transmission peripheral making them the perfect choice for high-volume applications. Worm gearboxes are applied in the mining and packaging industries, escalator driving systems, and micro appliances. 

Figure 2 Worm Gearbox

Figure 2: Worm Gearbox

Helical gearbox reducer for electric motor:

A helical gearbox is another common example of a speed reducer for the electric motor. Helical gears are the type of cylindrical gear reducers. These motors have slanted teeth ensuring a large and smooth contact ratio. Unlike other electric motors with gear reducers, these motors generate axial forces to carry out large forces. The coiled gear reduction motors produce minor vibration during operations. Some popular applications of helical gearboxes include domestic appliances, small cutting machinery, fertilizer industry, textile industry, and plastic industry. 

Figure 3 Helical Gear Motor

Figure 3: Helical Gear Motor

Hollow shaft gearbox:

The hollow shaft gearboxes transfer the RPM directly to the output shaft of the motor. The motors have extraordinary meshing features, making them the right fit for generating high revolution. Hollow-shaft gear reducer for electric motor provides high precision output. This type of speed reducer for electric motors is ideally suitable for direct torque transmission. The hollow structure and casing of this gearbox reduce the chances of overheating and sparks. Hollow Shaft reducer motors are suitable for industries where variable speed is a primary requirement; such as the automotive industry, power plant machinery, and pumping industry. 

XWD and BWD gearbox: 

XWD/BWD gearboxes are the type of cycloidal gearboxes. These gearboxes provide variable speed features to ensure the constant performance of the motor. XWD planetary gearbox is usually applied with the AC motor to control speed and maximize RPM value. BWD electric motor gearbox has unique meshing quality to handle high continuous rotations. The single-stage transmission of these gearboxes can reach up to 1:87 of speed/down ratio. Moreover, these gearboxes provide a 90% efficiency rate.

Figure 4 XWDBWD gear box

Figure 4: XWD/BWD gear-box

Advantages of speed reducer for electric motors: 

Electric motor with speed reducer provides exceptional benefits to the overall machinery. Some noteworthy advantages of using a gearbox reducer for an electric motor are discussed below;

  • Gearboxes elevate the rotations of the motor. Thus, it increases the RPM value and performance of the electric motor. 
  • The gearbox reducer for the electric motor controls the speed of the motor as per machinery requirements. Moreover, it allows variable speed to ensure constant performance. 
  • An electric motor with a gear reducer is cost-effective and has low power consumption. 
  • Speed reducer for electric motors is highly reliable providing accuracy and precision. 
  • Gearboxes have high load-carrying capacity; therefore, they are good enough for high-volume industries.
  • Unlike standard motors, the gearbox reducer for electric motors allows shorter and more accessible positioning. 
  • The electric motor with a gear reducer has a smaller size as compared to other motors.

How to select the right speed reducer for an electric motor: 

To select the best gearbox, you must understand your application requirements and the fundamental characteristics of different gearboxes. While finalizing the speed reducer for the electric motor, a person should consider the following factors; 


The efficiency rate of the gearbox plays an imperative role in the overall working of the speed reducers. If the power output does not match the driver’s power, the gearbox will fail to convert the power efficiently. Therefore, it is important to analyze the efficiency of the speed reducer before purchasing. The power output of the electric motor with gear reducer must match the driven load power. 

Speed output:

Another significant feature of gearboxes is speed output. The gearbox must maintain and control the speed of the electric motor according to the equipment requirement. However, it should not decrease the operational capacity or performance of the electric motor. 

Torque output:

The rotation rate of the gearbox is the crucial factor in choosing the right gear reducer for your application. The gearbox must generate enough revolutions to start and run an electric motor. To accelerate the connected equipment, a speed reducer for the electric motor must output high and frequent turns. 


Any sort of resistance impacts the performance and normal working of an electric motor. Errors in the tooth and meshing of gear adversely affect the gearbox. The gear reducer may experience mechanical stress or distortion. To avoid premature electric motor failure, you must select the gearbox with a low amount of resistance. Low resistance electric motor gearboxes are long-lasting and durable. 

Xinnuo Motor is a top electric motor manufacturer in China that offers a diverse range of electric motors including OEM motors, three-phase motors, and explosion-proof motors.


Speed reducer for electric motor impacts overall performance and ability of your motor. Electric motor with gear reducer overall scale down cost of the machinery.  Gearboxes make your equipment long-lasting, reliable, and highly functional. Moreover, Xinnuo’s customer care is 24/7 available to discuss your queries. Contact us for further inquiries and free quotations. 

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