The difference between brushed motors and brushless motors
The differences between brushed motors and brushless motors include whether they are equipped with ordinary brushes and commutators, their application range, service life, performance, and energy saving.
A brushed motor is a rotating electric machine that contains brushes and converts electrical energy into mechanical energy (motor) or mechanical energy into electrical energy (generator). Brushed motors are the foundation of all electric motors, characterized by rapid starting, timely braking, smooth speed regulation over a wide range, and relatively simple control circuitry. Commutation in a brushed DC motor is always achieved through the contact between graphite brushes and the annular commutator on the rotor. In contrast, a brushless DC motor uses Hall effect sensors to feed back the rotor position to the control circuit, allowing it to determine the precise timing of commutation.
Brushed motors are chosen by most domestic electric bicycle manufacturers. They use carbon brushes as the two contacts for the motor's power supply, controlled by a speed control handle and controller. Through secondary gear reduction and an overrunning clutch, they achieve stepless speed regulation from 0-20 km/h. High-speed brushed motors use high-quality metal, with strong, wear-resistant reduction gears and a reasonable design, resulting in a low repair rate. Furthermore, the cost of repairing and replacing gears and the motor is relatively low, effectively reducing the maintenance cost of electric bicycles. Brushed motors can also achieve easy manual riding using an overrunning clutch and flywheel. Brushed motors employ brushed mechanical commutation.
Brushless motors in electric bicycles require speeds of 35 km/h or higher to achieve optimal efficiency. However, as electric bicycles are regulated as non-motorized vehicles, their speed must be below 20 km/h. Therefore, choosing brushless motors for electric bicycles reduces efficiency and makes them less desirable. A key advantage is low noise. Brushless motors use electronic commutation and also include polarity detection elements.
Functional differences between brushless motors and brushed motors:
1. When a brushed motor is working, the coil and commutator rotate, while the magnet and carbon brush do not rotate. The alternating change of the direction of the coil current is accomplished by the commutator and brushes that rotate with the motor.
2. Brushed motors are traditional products with relatively stable performance. Brushless motors are upgraded products with better lifespan and performance than brushed motors. However, their control circuits are more complex, and the requirements for component aging screening are more stringent.
3. A brushless DC motor consists of a motor body and a driver, and is a typical mechatronic product. Because a brushless DC motor operates in a self-controlled manner, it does not require an additional starting winding on the rotor like a synchronous motor that starts under heavy load with frequency conversion speed regulation, nor will it experience oscillation or loss of synchronism during sudden load changes.
4. Brushless motor equipment can be used in: dairy industry, brewing industry, meat processing industry, soy product processing industry, beverage processing industry, pastry processing industry, pharmaceutical industry, electronic precision factory, and other cleanrooms with higher requirements. For example, the brushless motor (DIHOUR) hand dryer produced by Dior Electric is widely used in factories.
5. Carbon brush motors are only suitable for areas with less stringent requirements, such as various restrooms, and cannot be used in cleanrooms or explosion-proof workshops!
6. Service life: Brushless motors can operate continuously for approximately 20,000 hours, with a typical service life of 7-10 years. Carbon brush motors can operate continuously for approximately 5,000 hours, with a typical service life of 2-3 years.
7. In terms of energy saving, relatively speaking, the power consumption of a brushless motor is only 1/3 that of a carbon brush.
A brushed electric drill is a type of electric drill whose motor uses carbon brushes to contact rectifier copper plates on the stator to supply power to the coils of the motor rotor, which in turn forms a rotating magnetic field with the stator, driving the rotor to rotate and thus causing the drill bit to rotate.
A brushless electric drill refers to an electric drill that uses a brushless motor. The so-called brushless motor is because the rotor of the motor does not use coils to generate a magnetic field. Instead, magnets are used instead of rotor windings to work with stator windings to generate a rotating magnetic field and electromagnetic torque to drive the drill bit.
