The difference between DC brushless motor and brushed motor in miniature pumps application
Background:
Among the DC motors, the brushed motor is the first type of motor that everyone came into contact with. The motor was introduced in the physics class in middle school and it was also used as a model to show. The DC brushless motor is a relatively new type of motor, which has only been gradually applied to daily life in recent years.
But in fact, as early as 1917, the basic idea of the brushless DC motor was born, because the brush of the brushed motor is easily worn out, which is a fatal shortcoming, which affects the overall application of the brushed motor in the field. People need It is replaced by a motor that can be used for a long time without maintenance.
It was not until 1955 that D.Harrison and others in the United States applied for the first patent for replacing the mechanical brushes of brushed DC motors with transistor commutation circuits, which officially marked the birth of modern brushless motors. So what’s the difference?
Principle of brushed motor:
The basic structure of a brushed motor is: stator (magnetic pole), rotor (coil), mechanical brush (carbon brush) and commutator. The basic working principle of the motor is to obtain the rotational torque through the commutation and rotation of the magnetic field, so as to output the kinetic energy. The mechanical brushes and commutator of the brushed motor play the role of conduction and commutation during rotation, so the brushes and commutator need to be in constant contact and friction, and the carbon brushes need to be replaced regularly.
Principle of brushless motor:
The basic structure of a brushless motor: stator (coil), rotor (magnetic pole), position sensor (Hall sensor) and controller. The basic working principle of the motor is also to obtain the rotational torque by changing the magnetic field, so as to output the kinetic energy. The position sensor and controller are equivalent to the role of electronic commutation.
When the brushless motor is working, the coil does not move and the magnetic pole rotates. Through the Hall element, the position of the magnetic pole of the induction magnet is sensed. According to this induction, the direction of the coil current is switched in time to ensure that the magnetic force in the correct direction is generated to drive the motor. Eliminated the Disadvantages of mechanical commutation of brushed motors
Performance Difference Analysis:
1. The structure of the brushed motor is simple, the cost is low, and the failure is easily caused by the wear of the carbon brush. Because brushless motors are removed and electronic commutation is used, the cost is more expensive, but from a mechanical point of view, brushless motors are almost maintenance-free.
2. Another advantage of brushless compared to brushed motors is low interference. There is no electric spark generated when brushed motors are running, and digital signal control greatly reduces interference to other equipment.
3. In terms of noise, the smooth running brushless motor has no brushes, the friction force is greatly reduced during operation, the operation is smooth, and the noise will be much lower.
4. In terms of speed regulation, the control of brushed and brushless motors is essentially by adjusting the voltage, but the brushless DC adopts electronic commutation, uses thyristor and other circuits to control, and realizes it through digital control.
The brushed motor is to adjust the power supply voltage of the motor, change the strength of the magnetic field generated by the electrodes, and achieve the purpose of changing the speed. When the brushless motor speed is adjusted, the power supply voltage of the motor remains unchanged, the control signal of the ESC is changed, and the switching time of the MOS tube is changed through the internal controller to achieve the purpose of speed change.
Our miniature pumps
Both brushless and brushed motors are used in Hilin miniature pumps. For brushless series products, Hilin brushless motor micro pumps have built-in motor controllers, customers do not need to purchase and integrate motor drive control circuits, and our company integrates the motor drive control circuit according to the characteristics of the miniature pumps. A variety of control functions, such as a variety of speed regulation methods: PWM speed regulation, frequency speed regulation, knob speed regulation, touch speed regulation and 485 communication (based on Modbus communication protocol), etc.
At the same time, we can also provide customers with customized requirements to meet more customer application scenarios. After our laboratory life test, the brushless motor miniature pumps have found that the service life can reach more than 10,000 hours under the maximum load condition. If it is no-load gas transmission, the service life can be longer. It is suitable for occasions where the load is continuous and does not stop . For brushed series products, the advantages are low cost, relatively low power consumption, suitable for occasions with intermittent use and low cost control requirements.
Brushed air miniature pump series products:
Air miniature pumps: C13, D17, D25, etc.
The main features of this series of brushed motor vacuum pumps are: low power consumption, low cost, small size, and can provide industrial-grade reliability and airtightness within its nominal lifespan, and can operate continuously with a large load under its nominal vacuum degree.
Brushless air-liquid miniature pump series products:
Vacuum miniature pumps: C15, C09, C26, C30, C50, C60, C61, etc.
Miniature pumps compressor: D15, D23, D35, D50, D60, etc.
Micro liquid pump: S15, S23, S36, etc.
This series of products are long-life miniature pumps, all of which adopt DC brushless motors and integrate brushless motor controllers. They can be used immediately after power-on, and can adopt various speed regulation methods according to customer application scenarios. This series of miniature pumps can run continuously for a long time under the maximum working load, and the maximum load life exceeds 10,000 hours. If it works under light load, the life can far exceed the nominal life.