A DC gear motor is an electric motor (Figure 1) and a power reducer (Figure 2) combined into a single unit (Figure 3) that reduces the number of revolutions but increases the torque of the operating shaft.

This type of DC gear motor usually has a housing made of plastic and a gear made of metal, ensuring a low noise level during operation of the device. In addition, this design allows the voltage to be varied between 12 and 24 V to accommodate different application needs.

Such motors offered by brands such as DongHui Motor have excellent performance and reliability and are widely used in various applications.

Gear motor descriptions

Gear motor also called geared motor is a small electric motor (AC induction, permanent magnet DC, or brushless DC) designed with a permanent, integral (non-separable) gear reducer (gearhead) attached.

The end shield on the drive end of the motor (light blue, below) is designed to provide a dual function. The side facing the motor provides the armature/rotor bearing support and a sealing provision through which the integral rotor or armature shaft pinion passes.

The other side of the motor end shield provides multiple bearing supports for the gearing itself, and a sealing and fastening provision for the gearhousing (orange, below).

This construction offers many benefits for a user and eliminates the guesswork of sizing a motor and gear reducer on your own.

General speaking, gear motor function as torque multipliers and speed reducers, requiring less motor power to drive a given load. The gear housing design, the gearing type, gear lubrication, and the specific mode of integration all affect the gear motor performance.

Why are gear motor used?

The following benefits are why gear motors are been used in several applications and industries.

1. Cost savings

Using a gear motor to multiply torque, and reduce speed helps to decrease the overall cost of operating the system. The efficiency and reliability of the gear motors offers benefits to an application immediately.

Many gear motors are inexpensive to install and require little maintenance, meaning there will be less unscheduled downtime to repair the gears.

2. Environmental benefit

Efficient speed reducers can achieve significant savings, both in energy and drive component costs. In addition, gear motors also assist the environment and the workers operating them.

Industrial electric motor systems are responsible for approximately 1/12 of all greenhouse gas emissions from fossil fuel power plants. By reducing motor power consumption with efficient speed reducers, like gear motors, the production of greenhouse gases can be significantly reduced.

3. Increased Rigidity 

Geared motors are more robust and resilient to tensional stresses. As a result, as compared to conventional motors, geared motors are less prone to problems generated by load torque variations.

Even though the load fluctuates, high stability and position precision may be expected. For instance, higher gear tension in a geared motor gives more holding torque, allowing a surveillance camera to remain in place even in high gusts.

 4. Speed reduction

Gear motors are also known as gear reducers because as they increase output torque they decrease output speed. A motor running at 1,000 rpm fitted with a 5:1 ratio gearhead outputs 200 rpm. This speed reduction improves system performance because many motors do not operate efficiently at low rpm.

5. Torque

Gear motors provide an advantage when directly coupled to the motor output shaft. This creates a mechanical advantage based on a ratio between the number of gears and the number of teeth on each gear. For example, if a motor generates 100 lb-in. of torque, attaching a 5:1 gearhead generates an output torque of 500 lb-in.

6. Silent Operation

Quiet operation due to integral castings and integral pinion, ground or hobbed on the armature or rotor shaft. Few parts requiring assembly resulting in “near perfect” alignment of the rotor, pinion and geartrain.

7. Low Leakage

Minimum risk of lubricant leakage, because of “O-ring” and lip seal construction. The design can be more compact and the lubrication can be controlled better (for various mounting configurations).

8. Reduced Alignment Problem

Gear motors eliminate the need for motor/gearhead couplings and eliminate any potential bearing alignment problems, common when a motor and gearhead are bolted together by an end-user (separable gearheads). Misalignment can result in bearing failure due to fretting corrosion.

What are the DC gear motor specifications?

There are different gear motor specifications and their price varies accordingly. See few examples below:

1. Gear DC Motor 12V 300RPM comes in price range of $20 – $25 for the Specification below

Specifications

Rpm – 300 shaft

Diameter – 6mm (with internal hole)

Shaft length: 15 mm dimensions

Gearbox diameter: 37mm

Motor diameter: 28. 5 mm

Torque: 8 kgcm

Voltage: 6 to 24 (nominal voltage – 12v)

Load current: 9a (max)

2. DC Gear Motor 12v 100 rpm, in the price range of $15 to $20 and comes with the following specifications:

Specification

Rated voltage: 12 V

Gear reduction ratio: 50:1

D output shaft diameter: 6 mm

No-load speed: 100 RPM @ 12 v

No-load current: 0.17 A

Rated speed: 93 RPM @ 12 v

Current rating: 0.68 A

Rated torque: 7 kg.cm

Stall torque: 12 kg.cm

Stall current: 2.19 A

Power: 5W

Weight: 210 g

3. DC Gear Motor 12v 60 rpm, in the price range of $9 to $13

Specifications:
Voltage: 12V
Speed: 60RPM
Material: Metal
Rated Torque: 6.5Kg.cm
Reduction Ratio: 1:57.7
Rated Current: 0.06A
D Shaped Output Shaft Size:6*14mm(0.24″x0.55″)(D*L)
Gearbox Size: 37x25mm(1.46″x0.98″)(D*L)
Motor Size: 36.2×33.3mm(1.43″x1.31″)(D*L)
Mounting Hole Size: M3 (not included)

What is the dc gear motor working principle?

When corresponding DC gear motor are connected, the output speed can be effectively reduced and the output torque can be increased. In other words, the addition of a gearhead to a motor lowers the speed while increasing the torque output.

The torque of the DC geared motor can be obtained by the structure of the gearbox connecting to each other. While it is obvious that the function of DC geared motor is to move or rotate the final desired shaft at a desired slow RPM than a motor.

With this reduced RPM, the DC motor will turn into a high torque geared DC motor which will be able to impart higher torque to the shaft or to be rotated item.

Therefore the operating principle of DC gear motor involves passing of electric current through the rotor to the commutator because it is in the magnetic field, it rotates. This rotational force is used to perform mechanical work.

The working principle of PMDC gear motor is just similar to the general working principle of DC motor. In other word, it works to make it possible to create the ideal torque output and speed that you need.

Where is DC gear motor used?

Now that you have a better understanding of what geared motors are, let’s learn more about their applications in various industries.

1. The Paper Industry

The paper sector is seeing a boom in popularity, which is driving up demand for gearboxes. In the paper business, a broad range of gearboxes consisting of aluminum alloys, steel, and cast iron are utilized to ensure the smooth operation of the machines. Shaft mounted and spur gearboxes are two types of gearboxes that are widely utilized in this sector.

2. The Cement Industry

The cement industry requires gearboxes that are robust and capable of carrying more torque, depending on the size of the engine used in the processing.

Thus, gearboxes such as the Bevel Helical Gearbox and Parallel Shaft are utilized to provide functions such as engine augmentation, speed decrease, and many more. Gearboxes are used in this sector to boost the amount of engine torque to the maximum feasible level.

3. The Sugar Industry

It is one of the largest industries that employs a wide range of machinery. More machines necessitates the use of a wider range of gearboxes, such as planetary, helical, and so on, to meet the demands of various ratios and torque capabilities.

The gearboxes utilised in this industrial unit are available in standard configuration. Whatever sort of gearboxes are employed in the sugar industry’s operation, the end result is well-organized and sound machine operation, resulting in a favourable outcome.

4. The Steel Industry

This is another industrial plant that requires precise gearbox usage due to the employment of heavy equipment in the manufacturing process. The machines here are robust; therefore they demand the usage of industrial gearboxes that are long-lasting and robust in their operations.

For the smooth and long-lasting operation of the equipment, gearboxes such as pinion helical, planetary, and many more are utilized in this sector.

Other uses of DC gear motor includes Power windows, Windshield wiper systems, Power seats, Door locks, Sunroof mechanisms, Power mirrors.

• Robotics: Robotic arms, Mobile robots, Humanoid robots, Drones
• Medical devices:  Medical pumps, Surgical robots, Dental drills, Prosthetic limbs, Mobility devices
• Consumer electronics: camera focus and zoom mechanisms, DVD drives, game consoles, toys, home automation systems, automated blinds and curtains, pinball machine, coffee machines, printer, intelligent door lock, fitness equipment, ATM machines, Vending machines, coin changing machines, massage tools, smart home devices, adjustable lift table
• Renewable energy: solar tracking systems, wind turbine pivot control, water pumps, robotics for maintenance and repair
• Aerospace: control of aircraft flaps, guidance systems for rockets, positioning of satellite dishes, robotic arms for space exploration

What is the efficiency of a geared DC motor?

Efficiency of DC gear motor refers to the amount of mechanical power that is actually being transferred to the load (i.e., the output) compared to the amount of electrical power that is being input into the motor.

It essentially measures how much of the electrical power is being converted into useful mechanical work and how much is being wasted as lost energy due to various factors such as friction, heat, and inefficiencies in the motor and gear train.

Factors affecting efficiency of DC gear motor 

The efficiency of a DC gear motor can be influenced by several of the below factors:

• The design of the motor and gear train
• The quality of the materials used
• The level of friction in the system
• The speed and torque requirements of the application
• The operating conditions such as temperature and load.

In general, DC gear motors have relatively high efficiency. Some models are capable of achieving efficiencies of 80-90% or higher.

Adding gears to the motor can decrease efficiency due to increased friction and mechanical losses. However, this can be offset by the benefits of increased torque and speed reduction.

Is the efficiency different for a 12V gear motor and a 24V gear motor?

Generally speaking, a 24V gear motor can provide higher efficiency than a 12V gear motor, all other things being equal. The higher voltage allows for the motor to run at a lower current. This reduces losses due to heat and resistance in the motor windings and other components.

However, it’s important to note that the efficiency of a gear motor can vary depending on the load conditions. In some cases, a 12V gear motor may be more efficient than a 24V gear motor if the load is light and the motor is not operating near its maximum torque or speed.

I believe you have a certain understanding of the gear motor product. Read this article: what is the gear motors? to learn more about gear motor.

How to maximize the efficiency of a DC gear motor?

The below factors are important to maximize the efficiency of a DC gear motor:

• Select the right motor and gear combination for the specific application
• Operate the motor within its rated conditions
• Minimize sources of friction and losses in the system.
• Regular maintenance and lubrication can also help to improve the efficiency and lifespan of the motor.

What is the difference between AC and DC gear motors?

We have covered the differences between gear motors and stepper motors in our previous articles, here we will continue to introduce you to AC gear motors and DC gear motors. There are some similarities, but they also have key differences that make each Motors are better suited for specific applications.

1. Power

DC gear motors tend to have higher torque and power output than AC gear motors. This is due to the fact that DC gear motors use a commutator to switch the current direction, which allows for more efficient use of the magnetic field.

This makes DC gear motors ideal for applications that require high performance, such as robotics or heavy machinery. AC gear motors, on the other hand, are better suited for applications that require constant speed, such as conveyor systems or pumps.

2. Efficiency

AC gear motors are generally more energy-efficient than DC gear motors. This is because AC gear motors do not require a commutator, which can cause energy loss due to friction and heat.

Additionally, AC gear motors can be designed to run at higher speeds, which reduces the need for gearing and Improves efficiency. This makes AC gear motors a better choice for applications that require constant speed and high efficiency.

3. Speed control

DC gear motors offer more precise speed control than AC gear motors. This is because DC gear motors can be easily controlled by adjusting the voltage or current.

This makes DC gear motors a better choice for applications that require precise control, such as medical equipment or robotics. AC gear motors can also be controlled but typically require more complex control systems and may not offer the same level of precision.

4. Cost

DC gear motors tend to be more expensive than AC gear motors. This is due to the fact that DC gear motors require more complex control systems, such as motor controllers and feedback devices, which can add to the cost.

Conclusion

DC motors are vital components used in a wide range of applications, from household devices to industrial machinery. Their ability to provide precise speed control and high starting torque makes them versatile and valuable in various industries.

After reading this article, I believe you must have found some answers. Here is an article about a comprehensive guides to choosing a DC motor, you can read it if you need it.