Brushless motor How is it different from conventional motors?
brushless motor How is it different from conventional motors?
Motors are designed to convert electrical energy into mechanical motion. The market is full of different types of motors that can accommodate different applications. and different power requirements. The two most common types of motors are brushless motors. and carbon brush motor Although they use the same physical principles, their structure, performance, and controls differ greatly. And in this article we will tell the difference between these two motors.
Brushless motors are becoming increasingly popular with hobbyists, DIY enthusiasts and professional users. To understand the origin of these motors It is important to look back at the invention of Mr. Ernst Werner von Siemens in 1856. But these inventions have been improved many times over the past several decades. One of which is a rheostat for precise control of the rotation speed of the shaft.
Trickey has published an article on DC-operated brushless motors. The unit is equipped with technology that takes advantage of magnetic fields and is constantly resisted by electrical devices. The key revelation behind the concept of brushless motors is the absence of physical switches to transmit current. however Until the 1980s, brushless motors started really well. The greater availability of permanent magnets in combination with high-voltage transistors allows this type of motor to produce as much power as a brushed motor. The improvement of brushless motors has continued over the past three decades. This has changed the way drill manufacturers produce efficient drilling tools. In turn, customers are taking advantage of the key benefits associated with reduced versatility and maintenance requirements.
What is a brushed motor?
Carbon brushed motors are the most common DC motors. Its principle also consists of the attraction of two opposite poles of magnets. The main parts of the motor are the Stator rotor (armature), carbon brushes, commutators, permanent magnets, or electromagnets are placed on the stator and create a constant magnetic field. The electromagnetic DC motor is driven by the same DC source as the rotor.
The rotor is connected to a DC power source with a brush. The brush is attached to the commutator. Different windings are connected to different sections. such commutation When energized, it creates a magnetic field. when the rotor turns its magnetic field will change. Switching this field is called a shuffle. Current flows from the source to the coil. As a result of Lorentz's law, a magnetic field is generated and begins to interact with the magnet on the stator. The brush (which is commonly made of graphite) transmits energy to the armature. To maintain a snug fit, the commutator The spring exerts pressure on it.
In the simplest mechanism with one armature Problems can arise when the armature is perpendicular to the magnetic flux. In this case, the torque is zero and the motion is interrupted for a short time. so for smoother movement, Therefore, additional loops were added to the design. The more iterations The smoother the movement, the better. during the operation of such equipment Internal electromotive force (EMF) and counter emf (Back EMF) usually occur according to Faraday and Lawrence's law. Due to this, a large amount of heat is generated. Therefore, in a large and powerful motor, It is necessary to install additional cooling equipment to avoid the fire itself.
Advantages Motors have carbon brushes.
- cheap price
- Simple design and wiring
- Easy maintenance
- Reliable for mechanical shocks and vibration
Disadvantages Motor has carbon brushes.
- The brush wears out quickly.
- There is electromagnetic interference.
- sparks during operation
- This mechanism is overheating.
- low efficiency (about 60-80%);
- Due to the high friction of the brush, the service life is reduced.
What is a brushless motor?
The working principle of both types of motors is generally similar. It is based on the interaction of permanent magnets in the rotor. and electromagnets in Inrunner and Outrunner bldc type stators. The brushless DC motor (also called BLDC or simply BL) is a synchronous device and acts like a PMSM (magnetic synchronous motor). permanent). Therefore, its working principle is based on manual control of the synchronized frequency on the rotor. and the stator is exposed to the same frequency.
In the first case, the rotor is above the stator. and in the second case under the stator in such design, The rotor has a permanent magnet and the stator has a coil arrangement that creates an electromagnet. The basic principle of action is based on their interaction. The source power energizes the coil. and create a magnetic field when it occurs These energized coils are attracted to opposite poles located on the rotor. These windings are mounted in the rotor. So it started to spin as well.
when they approach the opposite pole The power goes out and the commutator starts to power the next pair. The next pair of coils was also attracted. So the rotor can continue to move. The action is then repeated continuously. The BLDC has a special design that allows the user to power any coil. Therefore, the torque and rotation speed can be changed quickly. The brushless motor is compact with high speed and precise positioning at the same time. Brushless motor, no friction, Therefore, the rotational force is greater than the heat. This was done due to the lack of carbon brushes. instead of using these devices The built-in commutator monitors and controls the rotor position. rotation speed and a constant current distribution throughout the coils themselves. Typical types of motors have three-phase windings on the stator and permanent magnets on the rotor. It is also done in single-phase, two- or three-phase form as mentioned above. The stator winding creates a rotating magnetic field. which drives the magnetic rotor to move. to create such a magnetic field. A three-phase voltage will be applied to the brushless DC main profile winding.
Brushless Motor Advantages
- Long service life
- low volume
- indicators of high efficiency - about 90%;
- The maximum rotation speed is fast.
- No sparks during use
- No additional heat source is required.
- There are no mechanisms that require regular maintenance.
Disadvantages of brushless motors
- Complex management system
- Limited electrical equipment resources?
- High price due to expensive components
- Requires additional switching equipment to work.
Summary of differences between brushed motors and brushless motors.
An electric motor is a device that converts electrical energy into mechanical energy. Process efficiency depends on the design and type of current (AC or DC). In a nutshell, what is the difference between a brushed motor and a brushless motor?
1. The brushless motor is assembled and more compact. but must be equipped with an additional switching device (controller, rotary encoder, drive).
2. The brushed motor is cheaper and easier. They can be wired directly to a DC source and have simple initial controls (such as switches).
3. In brushless form The rotor rotates electronically in another way. Mechanically rotating brushed armature (current transmitted through the brush)
4. The brushless one has three wires for connection and the brushed one has two.
5. The brushless motor is more efficient (85-90%), then brush (75-80%), which means with the same power. The first one will change a large rotational force. Because it does not create friction and does not lose much heat during operation.
The difference between a brushed motor and a brushless motor
Maintenance-free brushless motor and no spark This is because no mechanical commutators or brushes wear out. and the inertia of the shaft is less audible and torque-to-weight ratio It is therefore much smaller than comparable brushed motors.
Compared to brushed motors, BLDC motors have a number of efficiency advantages. They have high starting torque and flat torque up to rated speed. due to the real-time electronic control system, The speed control is therefore precise. and is not sensitive to changes in load This is because heat is generated in the external stator. and not an internal rotor So it's easier to keep cool. And the absence of brushes makes it less electrically sound. and can run at higher speeds In some cases, up to 100,000 rpm.
which one is best for you
Today, brushless motors are much more common than brushed motors, however, both can be found in a wide variety of applications. Brushed motors are still frequently used in household appliances and in automobiles. They also maintain a strong industrial niche due to their ability to modify the torque-to-speed ratio specific to brushed motors.
with credibility and long service life, Brushless motors have expanded to a wide range of applications. It is common in many industries, including manufacturing, computing, and many more. The next generation of electric vehicles and even POWER TOOLS Some even use them! Due to the vastly different needs and environments, The motion control scheme thus benefits from both motors.
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Original link https://itoolmart.com/blog/content/7dbt0
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