After massive demonstration about gear motor, you may have a basic command of what gear motor is. Just as the planetary gear motor is named by the gearbox of gear motor, 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. Brushless motor refers to the motor without brush and commutator (or slip ring), also known as commutatorless motor. There are AC motors and DC motors for brushless gear motor, of which the brushless DC gear motor is a common one. We mainly talk about brushless DC gear motor below.
How Does A Brushless DC Gear Motor Work?
To understand how a brushless DC motor work, we need to introduce how the brushed DC gear motor. works first. 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 to 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 the direction of rotation of the motor will change as well.
A brushless DC gear motor generally utilizes a permanent magnet as its external rotor. As stated before, the windings are on the rotor for brush dc gear motors. Things are different for brushless motor. The windings are on the stator for brushless motors. In addition, it uses three phases of driving coils and a specialized sensor that tracks 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?
- Low noise. The brushless motor gear reduction has no brush. Therefore, the friction is greatly reduced during operation, making it possible for smooth operation. Hence, the noise is much lower. This advantage is beneficial for the stability of the model.
- Low interference. The brushless motor removes the brush. There is no electric spark generated when the motor is running, which greatly reduces the interference of the electric spark on the remote control radio equipment.
- Long service life, low maintenance cost. Without the brush, there will be no other abrasion except for the bearing. From the mechanical point of view, the brushless motor is almost a maintenance-free motor. Some dust removal maintenance will be needed.
- High efficiency. By adopting permanent magnets, the rotor has no loss of the magnet core.
- The brushless motor operates in a self-controlled manner and will 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.
- Cost is relatively high, compared to brush gear motor.
- If the operating environment is in a place with a high magnetic field or has been in contact with or close to a high magnetic field, the motor may stop working. Because the rotor of the motor is made of permanent magnets, it becomes magnetized after magnetization. The high magnetic field will change the magnetic field of the rotor or eliminate part of the magnetic, thus the motor will not work normally.
What Are the Applications of Brushless Gear Motor?
To sum up: the brushless gear motor has the characteristics of small size, light weight, long life, high efficiency, low noise, low vibration, no sparks, high reliability, good stability, strong adaptability. With its creditable performance, brushless gear motors can be used for audio-visual products, automobiles, digital cameras, mobile phones, automotive air conditioners, vacuum cleaners, heart pumps, etc.