Things You Should Know About Brushless Gear Motors
After learning lots of information about gear motors, you likely have a basic command of what a gear motor is. Just as the planetary gear motor is named by its gearbox, the brushless gear motor is classified by the motor it adopts. The brushless gear motor is made up of a brushless motor, gearbox, and a driver. A brushless motor refers to a motor without a brush and commutator (or slip ring) and is also known as a commutatorless motor. Brushless gear motors can have AC motors or DC motors. Of the two, brushless DC gear motors are more commonly seen. Read below for more information on brushless DC gear motors.
How Does A Brushless DC Gear Motor Work?
To understand how a brushless DC motor work, we first need to learn how the brushed DC gear motor works. A brushed gear motor consists of two parts: a stator and a rotor. The stator has magnetic poles (winding type). The rotor has windings. After energization, the rotor also forms a magnetic field (magnetic pole). There is an angle between the magnetic field of the stator and the rotor, which makes the motor rotate under the mutual attraction of the stator and rotor magnetic fields (the N pole attracts the S pole). Changing the position of the brush can alter the angle between the stator and rotor poles, thus changing the direction of motor rotation.
Brushless DC gear motors generally use a permanent magnet as their external rotor. For DC gear motors with brushes, the windings are on the rotor. For brushless motors, the windings are on the stator. In addition, they use three phases of driving coils and a specialized sensor that track the rotor position. After tracking the position change of the rotor, the position sensor commutates the current of the stator winding in a certain sequence (that is, detecting the position of the rotor pole relative to the stator winding, and generating a position sensing signal at a certain position, which is processed by the signal conversion circuit to control the power switch circuit).
What Are the Advantages and Disadvantages of Brushless Gear Motor?
Pros:
- Low noise. Since it doesn’t have a brush, friction is greatly reduced during operation, allowing for smooth operation. This means that the noise is much lower. This advantage is beneficial for the stability of the model.
- Low interference. With no brush, there is no electric spark generated when the motor is running, greatly reducing the interference of electric sparks on the remote control radio equipment.
- Long service life, low maintenance cost. Without the brush, there is no other abrasion other than the bearing. From a mechanical point of view, the brushless motor is almost maintenance-free – only dust removal is required every once in a while.
- High efficiency. By using permanent magnets, the rotor has no loss of the magnet core.
- The brushless motor performs self-controlled operation and does not oscillate and lose step when the load changes suddenly. By using a suitable conversion algorithm, the thermal performance is improved. A better motor speed range and response time can be achieved, making it possible for better electromagnetic isolation and torque response.
Cons:
- The cost is relatively high compared to brush gear motors.
- If the operating environment is in a place with a high magnetic field or somewhere that has been in contact with or is near a high magnetic field, the motor may stop working. Because the rotor of the motor is made with fixed magnets, it becomes magnetized. The high magnetic field will change the magnetic field of the rotor or eliminate part of the magnetic pull, preventing the motor from running normally.
How Can Brushless Gear Motors be Used?
In summary, the brushless gear motor has a small size, it’s lightweight, long lasting, high efficiency, low noise, low vibration, no sparks, high reliability, good stability, and strong adaptability. With their reliable performance, brushless gear motors can be used for audio-visual products, automobiles, digital cameras, mobile phones, automotive air conditioners, vacuum cleaners, IV pumps, etc.
