Ultimate Guide to DC Gear Motors

2023-07-24 10:15

The Ultimate Guide to DC Gear Motors


What is a DC gear motor?


A DC gear motor, also known as a reduction motor, is a combination of a DC motor and a gearbox. It is driven by the use of direct current. In most cases, a gearbox is added to limit the speed of the motor shaft and increase the output torque of the motor.  The most common DC gear motors are the 12V DC gear motor and the 24V DC gear motor.


What is the difference between a 12V DC gear motor and a 24V DC gear motor?


A 12V DC gear motor operates at 12 volts, while a 24V DC gear motor operates at 24 volts.

A 24V DC gear motor can provide more power and torque than a 12V DC gear motor, but it requires a higher voltage power source.


What is the basic functionality of a DC gear motor?


Because of their wide range of uses, DC gear motors are commonly used in small and mid-sized applications. To build a DC motor, a magnetic field must be generated. This magnetic field can be built using magnets and can be either an electromagnet or a permanent magnet.


The torque of the DC gear motor can be achieved by the structure of the gearbox. The DC gear motor moves or rotates the final desired shaft at a slower speed than a motor. This reduced speed enables the DC gear motor to transmit higher torque to the shaft or object to be rotated.


When an electric current passes through the commutator by the rotor, the rotor rotates due to the magnetic field. This rotational force is used to perform mechanical work.

DC gear motors are available with a variety of specifications. The most important specifications related to gearmotors are speed (rpm), torque (lb-in), and efficiency (%). To select a suitable DC gear motor, please calculate the appropriate load, speed, and torque.


The global DC gear motor market is expected to grow exponentially in the future due to the below factors:


  • Rising demand for power transmission tools in manufacturing units
  • Increasing attention to mechanical power transmission efficiency
  • Growing infrastructure in emerging areas


What are the advantages of a DC Gear Motor?


  • Geared motors are designed with a gear reduction system that allows them to produce high torque output at lower speeds. This makes them ideal for applications that require high torque, such as driving heavy loads or machinery.
  • Increased efficiency: By reducing the motor speed, a geared motor can operate at a more efficient point on its torque-speed curve. This can result in less energy waste and increased efficiency.
  • Better control: Geared motors can provide better control over speed and torque output than regular motors. This can be particularly important in applications that require precise speed or position control.
  • Compact design: Geared motors can be designed to be more compact than regular motors. This can be useful in applications where space is limited.
  • Lower cost: In some cases, a geared motor can be a more cost-effective solution than a regular motor. The required torque output comes at a lower cost




What are DC Gear Motors used for?


DC gear motors are versatile and can be used in various applications.

These are just a few examples of how DC gear motors are used in different industries.


What are the different uses of 12V DC Gear Motors and 24V DC Gear Motors?


12V DC gear motors are commonly used in automotive, marine, and robotics applications.  24V DC gear motors are commonly used in industrial applications such as conveyor systems, lifts, and other heavy machinery.


The choice of motor voltage depends on the specific requirements of the application. This includes power requirements, speed, torque, and available power supply.


What are the different industries DC Gear Motors are being used in?


With the increasing popularity of smart devices, DC gear motors are expected to be used in more and more applications in the future.


Industrial machinery:

Conveyor systems, packaging machines, material handling equipment,, assembly automation, CNC machines, printing machines, industrial robots.


Automotive industry:

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 stall torque of a DC Gear Motor?


Stall torque, also referred to as locked rotor torque, is the maximum torque that a DC gear motor can produce when the motor shaft is prevented from rotating.


This occurs when the motor is supplied with power but is unable to rotate due to an external force or load greater than the motor's output torque. In other words, the motor is "stalled" or held. The torque the motor produces at that moment is called stall torque.


Stall torque represents the maximum torque the motor will produce under load.

It is an important specification to consider when selecting a DC gear motor for an application.


Is there a difference between the stall torque of a 12V Gear Motor compared to a 24V Gear Motor?


The stall torque of a DC gear motor is not directly affected by the voltage rating. It is instead determined by the physical design of the motor. This includes the number of turns, the strength of the magnets, and the gear ratio of the gearbox.


However, the current drawn by the motor increases as the voltage increases. This  increase in current can result in higher stall torque.


This is because stall torque is proportional to the current flowing through the motor. Thus, a 24V DC gear motor can potentially draw more current and produce higher stall torque than a 12V DC gear motor of the same size and design.


However, high stall torque does not necessarily equal better motor suitability for a particular application. While high torque is necessary for some applications, such as heavy loads, it can also cause excessive wear on the motor and other components.


What is the torque of  a DC Gear Motor?


It is crucial to select a motor with appropriate stall torque for the specific application. This ensures reliable and efficient operation. Torque in a DC gear motor refers to the torsional force generated by the motor that is responsible for producing rotary motion.


In other words, it is the force exerted by the motor on the output shaft. In a DC gear motor, torque is usually generated by an electromagnetic field created by passing an electric current through the coils of the motor.


As the current passes through the coils, a magnetic field is created. This field interacts with the permanent magnets of the motor to create a rotational force.


The amount of torque a DC gear motor can produce depends on several of the below factors:


  • The size and strength of the motor's permanent magnets
  • The number and arrangement of the motor's coils
  • The gear ratio of the gearbox


In general, a larger motor and a larger number of coils can produce higher torque output.


Similarly, a higher gear ratio can increase the torque output of the motor. The torque of a DC gear motor is usually measured in Newton-meters (Nm) or pound-feet (lb-ft) and is an important factor in selecting a motor for a particular application.


What is the efficiency of a DC Gear Motor?


DC gear motor efficiency 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 lost due to various factors such as friction, heat, and inefficiencies in the motor and gear train.


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.


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.


The efficiency of a DC gear motor can vary depending on several factors:


  • The quality of the motor and gears
  • The load being driven
  • Speed and torque requirements


  1. Gear Train Efficiency: The efficiency of the gear train itself plays a critical role in overall motor efficiency. Friction and wear within the gears can reduce the efficiency of the motor.
  2. Motor Windings: The motor's windings can also impact efficiency. If the windings have high resistance, then they will generate more heat, which can reduce the motor's efficiency.
  3. Bearing Friction: The bearings in a motor can generate friction, which reduces efficiency. Choosing high-quality bearings with low friction can help improve the efficiency of a motor.
  4. Load: The load placed on the motor can also impact efficiency. Higher loads require more torque and can reduce efficiency.
  5. Operating Voltage: The operating voltage of a motor can also impact efficiency. Insufficient voltage can cause the motor to operate improperly. If the voltage is too high, it can cause the motor to overheat, reducing its efficiency.
  6. Ambient Temperature: The temperature in which the motor operates can also impact efficiency. Higher temperatures can cause the motor to overheat, which reduces efficiency.


Overall, a DC gear motor's efficiency is impacted by a variety of factors. It's important to consider these factors when selecting and operating a motor to ensure the highest level of efficiency.




How to reduce the noise of a DC Gear Motor



The sound of a low-noise DC gear motor during transmission can be less than 45 dB. The DC gearmotor consists of a drive motor (DC motor) and a reduction gear (gearbox). The low-noise DC gear motor improves the noise of the existing DC motor during operation.


The brushed DC gearmotor consists of the DC motor body with a rear cover. This includes the first oil bearing, brushes, rotor, stator, second oil bearing, and reduction gear.

The left side of the oil-bearing is located on the inside of the rear cover. The left side of the brush penetrates the inside of the rear cover, and the left ends of the brush are each inserted between the top and bottom of the right side of the rear cover.


The noise generated by a DC motor can be significantly reduced by implementing the below measures:


  • Use of special bearings that prevents excessive friction, thereby reducing noise caused by friction during operation.
  • Adjusting the brushes can minimize the friction between the brush and the commutator. This reduces the noise generated by the motor.


To avoid noise caused by the abrasion between the carbon brush and the commutator, rotary machining of the DC motor must be conducted with care. Furthermore, detailed technical parameters should be explored through experimentation.


Is the noise level different for a 12V Gear Motor and a 24 Volt Gear Motor? (H3)


In general, the voltage of a gear motor is not a primary factor in determining the noise level. However, the specific motor design and gear reduction ratio can impact the noise level of the motor.


Noise issues can arise if the carbon brush's main body is not smooth enough, or if the running-in treatment is inadequate. Over prolonged periods of operation, the commutator piece may also wear out. This can lead to problems such as overheating and loud noise. To address these issues, the main body of the carbon brush should be ground and lubricated completely. The commutator should replaced, and regular application of lubricating oil should be conducted to slow down the wear. Furthermore, bearing noise can be suppressed by replacing the DC motor bearings.


The below factors can damage the bearing:


  • Bearing compression
  • Incorrect force point
  • Shaft and bearing are too tight
  • Unbalanced radial forces are acting on the bearing.



How to choose the right DC Gear Motor


When choosing a motor, consider the purpose of an application and what current it uses. The optimal motor for an application is determined by its specifications such as voltage, current, torque, and speed. Therefore, it is important to carefully consider the requirements of the application.


Current drives the motor and too much current will damage the motor. For DC motors, operating current and stall current are important.


What is the operating current of a DC Gear Motor? (H3)


The operating current refers to the average current that the motor is expected to draw at typical torque. On the other hand, the stall current provides enough torque to keep the motor running at stall speed or 0 rpm. This is the maximum current that the motor can draw and the maximum power output when multiplied by the rated voltage. If the motor is continuously operated or is run at a voltage higher than its rated voltage, the use of heat sinks becomes necessary to prevent the coils from melting.


What are the rules around voltage for a DC Gear Motor?


The voltage applied to a motor should not be too low, as the motor will not function, nor should it be too high, as it may cause the windings to short out. This could result in power loss or even complete destruction of the motor. When considering torque, both operating and stall values must be taken into account.



What is the operating torque of a DC Gear Motor?


It's important to always pay attention to the required operating torque. However, in some applications, it's imperative to know how much the motor can be pushed. For example, in a wheeled robot, good torque is necessary for good acceleration, but it's important to ensure that the stall torque is strong enough to lift the weight of the robot. For this example, torque is considered more important than speed.


What are the rules around RPM of a DC Gear Motor?


Speed or velocity (RPM) can be complex when it comes to motors. The general rule is that motors run most efficiently at the highest RPMs, but it is not always possible when a gearbox is required. When selecting a gear motor, it's important to keep in mind that adding gears can decrease the motor's efficiency. Therefore, it's important to consider both speed and torque reduction.


Here are some considerations that can help you decide whether to choose a 12V gear motor, a 24V gear motor, or a 100 rpm gear motor.


  • Power requirements: The power requirements of your application will determine the voltage and speed of the motor you need. If your application requires high torque and speed, a higher voltage motor such as a 24V gear motor may be more appropriate. However, if your power requirements are lower, a 12V gear motor or a 100 rpm gear motor may be sufficient.
  • Efficiency: higher voltage motors tend to be more efficient than lower voltage motors because they require less current to deliver the same power. This means that a 24V gear motor will generally be more efficient than a 12V gear motor or a 100 rpm gear motor.
  • Size and Weight: If space and weight are a concern, a 12V gear motor or 100 rpm gear motor may be a better option as they are generally smaller and lighter than a 24V gear motor.
  • Cost: In general, 12V gear motors and 100 rpm gear motors are less expensive than 24V gear motors. If cost is an important factor, a 12V gear motor or 100 rpm gear motor may be the more economical choice.
  • Availability: The availability of the motor you need may also be a factor in your decision. If a 12V gear motor or a 100 rpm gear motor is more readily available than a 24V gear motor, it may be more convenient to use the 12V or the 100 rpm motor. It might require adjustments to your application.


Overall, the choice of a DC gear motor depends on the specific requirements of your application.


It is important to carefully consider factors such as power requirements, efficiency, size and weight, cost, and availability before making a decision.

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