Convenient rechargeable power tool motor application type

Brushed DC motor

The structure of conventional brushed DC motor includes rotor (shaft, iron core, winding, commutator, bearing), stator (chassis, magnet, end cover, etc.), carbon brush assembly, carbon brush arm and other parts.

Working principle: The stator of the brushed DC motor is equipped with a fixed main magnetic pole (magnet) and brushes, and the rotor is equipped with an armature winding and a commutator. The electrical energy of the DC power supply enters the armature winding through the carbon brushes and the commutator to generate an armature current. The magnetic field generated by the armature current interacts with the main magnetic field to generate electromagnetic torque, which causes the motor to rotate and drive the load.

Disadvantages: Due to the existence of carbon brushes and commutators, brushed motors have poor reliability, many faults, unstable current, short life, and commutation sparks will produce electromagnetic interference.

Brushless DC motor

The structure of the conventional brushless DC motor includes the motor rotor (shaft, iron core, magnet, bearing), stator (chassis, iron core, winding, sensor, end cover, etc.), and the controller and other parts.

Working principle: The brushless DC motor is composed of the motor main body and the driver, and it is a typical mechatronics product. The working principle is the same as that of the brushed motor, except that the position sensor and control circuit replace the traditional commutator and carbon brush, and the control command is issued through the sensing signal to complete the current direction conversion to realize the commutation work, and to ensure that the motor produces a constant electromagnetic rotation. Torque and steering make the motor rotate.

Analysis of Brushless DC Motor in Electric Tools

Advantages and disadvantages of BLDC motor applications

The advantages of BLDC motors:

Simple structure and reliable quality:

Eliminate the commutator, carbon brush, brush arm and other parts, no commutator welding, fine turning process.

long lasting:

The use of electronic components to replace the traditional commutator structure prevents the short life of the motor due to carbon brushes and commutator sparks, mechanical wear, etc., and the life of the motor is increased by multiples.

Quiet, high efficiency:

The structure without carbon brushes and commutator avoids the commutation sparks and mechanical friction between the carbon brushes and the commutator, resulting in noise and heat, resulting in motor energy loss and reducing motor efficiency. The efficiency of brushed DC motor is 60~70%, while the efficiency of brushless DC motor can reach 75~90%

More extensive speed regulation and control capabilities:

The use of precision electronic components and sensors can precisely control the motor output speed, torque and position, achieving intelligence and multi-function.