What is a DC brushless motor

There are many types of motors, and except for a few special types, most of them use magnetsNJiheSThe principle behind the rotation of the motor shaft (rotor shaft) is based on the magnetic force (attraction and repulsion) of the poles, as well as the magnetic field generated by the flow of current.

Among them, the motor that uses a DC power source to rotate the shaft is called a DC motor（DCElectric motors can be roughly divided into"brushed"and"Brushless（BLDC）".

So, what is an electric brush?
Electric brushes are DC motor components used in combination with commutators, and are one of the mechanisms that keep the DC motor rotating. That is to say, a DC motor with a commutator and brushes is"DC brushed motor"The use of electronic circuits instead of commutators and brushes in DC motors is"DC brushless motor（BLDC）".

The difference between DC brushed motor and DC brushless motor

In order to continuously rotate the shaft of a DC motor in a certain direction, a mechanism is needed that can reverse the direction of the current when the shaft (rotor) rotates half a turn. DC brushed motors use commutators and brushes to form a mechanical switching mechanism.

However, in this mechanism, the shaft rotates in contact with the commutator and brush, and prolonged rotation will cause the commutator and brush to age due to friction. That is to say, they are all consumables and require regular maintenance. Moreover, constant contact with each other can also cause electromagnetic interference and noise from the electric brushes.

For this purpose, the brushless DC motor is equipped with an electronic circuit to detect the rotation status of the shaft, eliminating the need for a commutator and brushes, and does not require regular maintenance, while also reducing electromagnetic interference and noise.

Working principle of DC brushed motor

Brushed motors use coils as rotors. When the rotor rotates, switch the commutator in contact with the electric brush. Thus, the coil through which the current flows is switched.
In this way, by timely switching the direction of the current, the rotor can continue to rotate.

Working principle of brushless DC motor

DC brushless motors use permanent magnets as rotors and do not require commutators or brushes. By detecting the magnetic pole position of the rotor and switching the coil through which current flows, the rotor rotates. Therefore, brushless motors require a driving circuit (driver). In addition, magnetic sensors such as Hall sensors should be used to detect the rotational position of the shaft (there are also sensorless methods that do not use sensors).

Hall sensors use the Hall effect to determine the strength of magnetic fields. By converting it into an electrical signal, the position of the permanent magnet can be detected（NExtremely stillSPole) and rotate the motor shaft by switching the coil through which current flows.

Characteristics of DC brushed motors and DC brushless motors

DC brushed motors and DC brushless motors have the following characteristics respectively.

Characteristics of DC brushed motor

advantage

• Without the need to control speed, there is no need for a driving circuit.

• Easy to control and use

shortcoming

• Will consume brushes and commutators, therefore maintenance is required

• Electric brushes can generate electromagnetic interference and noise

Characteristics of DC brushless motor

advantage

• The commutator does not need to be in contact with the electric brush, so it has a longer lifespan

• Can achieve high-speed rotation

• Good traceability and responsiveness

shortcoming

• Need to drive circuit

• The overall cost may be high

Types of DC brushless motors

DC brushless motors are divided into two categories: external rotor mode and internal rotor mode.

External rotor method

Install coils on the inner side and permanent magnets on the outer side to rotate the outer permanent magnets. It can achieve stable rotation.

Internal rotor method

Install permanent magnets on the inner side and coils on the outer side to rotate the inner permanent magnets. Like brushed motors, precise control can be achieved.

The purpose of brushless DC motor

DC brushless motors are characterized by their small size, high power, low vibration, low noise, and long lifespan. They are widely used in various fields such as air conditioning equipment (air conditioners, air purifiers, etc.), residential equipment, refrigerators, water heaters, vending machines, copiers, printers, projectors, commercial equipment, measuring instruments, automobiles, medical equipment, etc.

• air conditioning equipment

• residential equipment

• Water heater, burner unit

• vending machine

• Frozen and refrigerated display cabinets

• Financial terminal（ATM）Change machine, currency exchange machine, ticket vending machine

• clean room

• Optical Products

• printer

• copier

• Health equipment

• Commercial Equipment

• Testing analyzer

Using DC brushless motors to solve customer problems

Aspina's brushless DC motor is not simply a motor, but rather a system component provided as a drive/System products from control systems to institutional design. We provide a range of services from trial production to mass production and after-sales support.
We will provide the best solution according to the functions and performance required by various industries, uses, and customer products, in conjunction with the customer's production system.

We not only provide services for customers with clear expectations and specifications, but also offer support from development to mass production for customers who encounter various difficulties. Please feel free to inquire.

I don't know what kind of motor is needed

• "We are still in the early stages of new product development and have not yet produced specific specifications and design drawings. But in order to accelerate the future development process, we hope to receive some suggestions on drivers, systems, or precision motors."

• "There are no experts proficient in motors in the company, and there is a lack of motor knowledge required to achieve ideal operation."

The comprehensive design of the motor and its surrounding parts is too difficult

• "We want to invest our company's resources into product planning and core technology design and development. Is there any company that can provide comprehensive design and development services for motors and their surrounding areas beyond this?"

• "Modifying the motor requires modifying the design of other structural components, which may require a lot of time and effort."

There are no products that meet the intended use in the existing products……

• "We want to find a customized motor designed based on our company's products, but the motor manufacturer we are collaborating with has‘Our company's motor specifications cannot be changed'Refused on grounds."

• "We want precise control of the motor, but our existing motor products do not support it. Can we just give up?"