Longbank Brushless DC Motor

Are you looking for the best brushless DC motor supplier and manufacturer? Longbank is your perfect choice. We are proudly supplying different models of brushless DC motors to different countries in the world. Longbank is competent in providing all your brushless DC motors at competitive prices.

Longbank brushless DC motor contains a stator in polyphase armature windings and a rotor in the shape of a permanent magnet. The brushless DC motor features excellent controllability, power-saving advantages, and high efficiency. It is also used in different usage.

Our brushless DC motors bring high speed, torque, and efficiency. We designed numerous models for this product, available in your ideal dimensions to suit your application needs. Longbank keeps engineering performance enhancements for brushless DC motors to achieve your satisfaction. When you are looking for the right motor for your application, you may ask for assistance from us.

Here are 7 Advantages of Longbank Brushless DC Motors:

• Extensive operating life due to a lack of friction and electrical losses
• Better speed versus torque features
• Ultimate efficiency
• High powered response
• Higher speed ranges
• Noise-free operation

All of these mentioned features will help you raise your market sales. Longbank produces highly stable and effective brushless DC motors suitable for your applications. With our rich knowledge and experience, we can enhance the flexibility of our product that allows you to have more extensive applications.

You can have our top-quality brushless DC motors for specific applications, such as:

• Ventilation and heating
• Consumer electronics
• Model engineering
• Industrial engineering
• Transport

Providing you the superior quality brushless DC motors is our main mission. We will help you find the right motors for your business.

Longbank has an advanced fully automatic small motor production line to develop your brushless DC motor requirements. For over two decades in the field, we have gained rich experience in finishing 50,000 sets of motors per day.

Longbank can definitely accommodate your needs. Contact now!

The Ultimate FAQs Guide

If you’re looking for any information about brushless DC motors, you will find it right here.

This guide explores everything you need to know about brushless DC motors – from design, working principle, features, to specifications, among other vital aspects.

Keep reading to learn more.

What Are Brushless DC Motors?

These are also known as BLDC or electronically commutated motor [ECM]. Brushless DC motors are synchronous and get their electric power via direct current [DC] through switching power supplies or inverters.

This effect will generate electricity as alternating current [AC] that assists in driving every motor phase through a closed-loop controller system. Besides, brushless DC motors will eliminate the need to use brushes that flip electromagnetic fields.

Also, you will find permanent magnets on rotors whereas the stator will contain the electromagnets within a brushless DC motor. Computers then supply charge to electromagnets within the stator making it revolve at 360 degrees.

Figure 1 Brushless DC Motor

What Is A Brushed DC Motor?

This is a motor that you will commutate internally and operated from direct current [DC] power sources.

Besides, the motors within a brushed DC motor will rotate at 180 degrees if you supply the current electricity towards the armature. Also, the electromagnetic poles need to flip if you need to proceed further.

When the rotor are rotating, the brushes contact stators causing the magnetic fields to change thus, causing 360-degree turn on the rotors.

How Does A Brushless DC Motor And A Brushed DC Motor Compare?

From their names, the main difference lies in the application of brushes and the commutator in a brushed DC motor.

Alternatively, the brushless DC motors will apply electrical commutation to form mechanical energy from electrical energy.

Figure 2 Brushless DC Motor Vs. Brushed DC Motor

Here is how a brushless DC motor and a brushed DC motor compares:

• Range Of Speed

Since brushless DC motors lack commutators and brushes, the range of speed achievable is higher than that of brushed DC motors.

• Safety

Since brushed DC motors can produce sparks during operation, they are not suitable for applications with existing explosion risks.

This makes brushless DC motors the suitable choice when operating in hazardous operating conditions.

• Electrical Noise

Brushed DC motors produce more noise than brushless DC motors.

Electrical noise comes about when strong sparks occur in locations where the brushes will pass above gaps within the commutator.

For this reason, a brushless DC motor is common in areas that do not require electrical noise.

• Efficacy

It is possible for you to continuously control the maximum revolving torque in brushless DC motors.

However, brushed DC motors will achieve maximum levels of torque at specific points during the rotation.

Besides, you need to employ bigger magnets in brushless DC motors to enable them to achieve similar torque to a brushless DC motor.

For this reason, small brushless DC motors can achieve more power.

Brushed DC motors are ineffective since they lose power as there is a transfer of power and friction through the commutation unit.

This will make brushless DC motors more efficient as they lack mechanical losses that are present in brushed DC motors.

• Control Of Speed

It is possible to control the speed of a brushless DC motor than brushed DC motors.

Brushless DC motors enable this control using feedback systems that will precisely deliver suitable rotating speed and torque.

Having precise control enables you to minimize the generation of heat and consumption of energy.

It will also enhance the battery life where the motors are powered by batteries.

However, a brushed DC motor needs complex systems to enable speed control.

When you reduce the voltage, you will lower the torque of the motor.

This is costly as the torque will dip dramatically at lower speeds.

• Commutation

Brushed DC motors need brushes to relay current via mechanical commutation to the motor windings.

However, brushless DC motors employ electrical commutation when delivering current.

• Maintenance

Since brushless DC motors do not include commutators or brushes, they can do with minimal maintenance compared to brushed DC motors.

Depending on the working temperatures and environment, they need replacement after every 2 to 7 years.

• Life Span

The brushes within a brushed DC motor undergo wear and tear. This will make the brushed DC motors have a limited lifespan.

• Consumption Of Electricity

Several devices that employ brushless DC motors are mostly known as smart motors. This is due to the use of sensors that control resistance against the brushless DC motor for items such as electric drills.

For this reason, you can adjust the supply of current automatically. This feature makes such tools to be efficient in terms of electrical consumption.

• Characteristics Of The Speed Or Torque

Since brushed DC motors operate too fast, this makes them not suitable for use in several applications. This calls for the installation of fearing units that will minimize the speed which in turn will increase torque.

However, brushless DC motors are effective in this situation. This makes them useful in several situations as they operate efficiently without the installation of gearing systems.

Some specialist usages may install gearing units when they need a lot of torque or high levels of precision.

• Construction

The armature winding is on the rotors of the brushed DC motors with fixed magnets on the sides of the revolving electromagnets.

In brushless DC motors, the armature windings sits on stators while the fixed magnets are on the rotors.

• Price

Brushless DC motors are costly since they are complex and contain permanent magnets.

However, brushed DC motors tend to be affordable.

In Which Areas Will You Use A Brushless DC Motor?

There are several areas where you can use a brushless DC motor.

Some of them include the following:

• HVAC [heating, ventilation, and air conditioning]

These systems apply brushless DC motors in compressors, pumps, and fans. Refrigeration systems also apply brushless DC motors as it is beneficial.

• Transportation

Brushless DC motors are a popular type of motor to use in all vehicles.

These include:

1. Golf carts
2. Scooters
3. Wheelchairs
4. Drones
5. Small cars
6. Bicycles

• Manufacturing And Industrial

Many factories deploy many motors that are to control different types of machines. Some applications are in robotics and servo-controlled systems.

Brushless DC motors allow you to readily control torque and speed to cater to several requirements.

Since they are highly efficient and require minimal maintenance, brushless DC motors enable you to save costs on power and maintenance.

• Power Devices

Brushless DC motors are highly efficient therefore, battery-powered tools almost entirely apply these motors to their construction.

Some of these battery-powered tools include:

1. Saws
2. String trimmers
3. Drills
4. Electric lawnmower
5. Screwdrivers, etc.

Since they are highly efficient, brushless DC motors offer power and more duration between the charges and long battery life.

• Radio-Controlled Devices

Several radio-controlled units such as drones, cars, and aircraft are using brushless DC motors and abandoning the noisy internal motors from the past. Besides, they provide more power, efficacy, and durable battery life.

• Appliances

For electronics that major in durability, quietness, and performance, a brushless DC motor is the best choice.

Some of these appliances include:

1. Washers
2. High-end vacuum
3. Dryers, etc.

• Aeromodelling

Brushless DC motors are a popular selection for drones and helicopters. This is because they have a suitable power-to-weight ratio and come in varying sizes. One reason for their popularity is that they produce less noise.

Figure 3 Applications of Brushless DC Motor

Does A Brushless DC Motor Offer Any Benefits?

Rotors in brushless DC motors operate without friction making these motors beneficial in several areas.

Some of the merits of brushless DC motor include the following:

• It is possible for a brushless motors to function at higher speeds and torque.

This enables it to yield a lot of power output despite its size.

• High-speed functioning is particularly challenging for typical brush DC motors.

This is because a lot of energy that must be changed by the brushes is damaging and diminishes motor life.

The driving circuitry of brushless motors can manage this energy.

• There is a need to decrease the chance of the temperature increasing and lengthen the bearing durability.

To accomplish this, you can install heat sinks within stators that hold the motor winding.

• Where extended life is necessary, the lack of brushes usually extends the life of the motor comparable to that of the bearings.
• In applications that require a high level of cleanliness, brushless DC motors eliminate undesirable brush wear particulates.
• Brushless DC motors will eliminate electromagnetic interference [EMI] which comes about due to the arcing of brush commutators.

Besides, the controllers of brushless DC motors are free from electromagnetic interference.

• A brushless DC motor may be utilized in explosive conditions without the need for specific housing features.

This is in contrast with typical DC motors that require such housing to exhibit an explosion-proof feature.

• Even though the use of brushes has been applied in space conditions, they are costly and time-consuming. However, brushless DC motors require far less setup.

Does A Brushless DC Motor Have Any Limitations?

Some of the demerits of a brushless DC motor include:

• They need complex monitoring and drive circuitry, however, you can lower this by using modern semiconductor systems.
• It will cost you more to make a brushless DC motor, however, the benefits will overshadow this limitation.

What Components Will You Find In A Brushless DC Motor?

The parts on a brushless DC motor entail the following:

Figure 4 Parts of Brushless DC Motor

• Stator

This is a laminated steel core containing magnetic wire coils. Stators connect in one or several phases enabling the generation of rotating electromagnetic fields when you sequentially excite the phase windings.

• Rotor

Permanent magnetic fields are on the rotors of brushless DC motors. Besides, you can have the rotor within or outside the stator.

Also, an outer rotor arrangement offers permanent magnets with a rigid structure and has a higher level of inertia. Furthermore, you will use it in high-speed applications which needs a stiff structure to:

1. Counteract centrifugal forces that act on permanent magnets
2. Velocity loop usages where adding rotor inertia is suitable for stabilizing velocity
3. Extra inertia is unimportant to overall inertia

• Position Sensors

There are numerous ways that you can use to sense the position of rotors. It is vital to sense the position of rotors so that you can control the excitation of the stator winding.

The methods are as follows:

1. Photoelectronic
2. Electromagnetic
3. Magnetic

• Electronics

This module can sit within the motor housing or on the external PCB. It receives signals from position sensors then controls the switches by developing waveforms via digital logic systems.

What Is The Functional Principle Of A Brushless DC Motor?

A brushless DC motor produces rotational forces when two magnetic fields interact, the electromagnet and permanent magnet. When you put these two close together, the attraction and repulsion forces will produce the rotational force.

For the brushless DC motor to rotate, the stator winding, in specific sequences, is fed with several pulses. This causes the magnetic fields to collaborate and change with the rotor to produce motion.

Depending on the type and size of the brushless DC motor, the number of permanent magnets and stator windings vary considerably. The higher the number of pole-pair and stators, the more torque rotors can produce.

A majority of brushless DC motors use three winding groups to generate pulse sequences that work with the magnets of the rotors. These three groups of pulses will offer the capacity to rotate.

A brushless DC motor contain the following groups:

• One-phase brushless DC motors for low torque force fan usages
• Two-phase brushless DC motors using two-phase
• Brushless DC motor using three-phase

The rotation of a brushless DC motor depends on the timing of pulses that engage with permanent magnets. This means that controller circuits powering the stator coils need to know the state of the rotor before applying a sequence of pulses.

Some brushless DC motors contain sensors that will show the position of the rotors.

Figure 5 How Brushless DC Motor Works

Are There Brushless DC Motors That Are Highly Efficient?

The most efficient brushless DC motor is known as the sine-wave-driven motor. It applies a triple 120-degree sine wave that is shifted to generate rotation.

Besides, the sine waves’ applied amplitude is vital when you need to control torque and speed.

What Should You Consider When Choosing The Suitable Brushless DC Motor Rating For Your Application?

Selecting the right brushless DC motor for your application is important. Besides, you need to select the correct brushless DC motor based on the load traits.

Here are the factors worth considering when selecting a brushless DC motor for your requirements:

• Peak Torque

It is possible to calculate the maximum torque for your application by adding the following:

1. Torque that overcomes friction
2. Existing torque due to inertia
3. Torque load

• RMS Torque

This is the continuous average torque you need for your application.

RMS relies on the following:

1. Load torque
2. Acceleration
3. Peak torque
4. Deceleration
5. Torque because of inertia
6. Run times

• Operating Speed Range

This is the speed of the motor you need to drive your application and it relies on the application time.

What Is The Meaning Of Back EMF Within Brushless DC Motors?

The voltage that the windings generate when a brushless DC motor rotates is known as back EMF or back Electromotive Force. According to Lenz’s law, it will oppose the primary voltage that gets to the windings.

The polarity of back EMF contradicts the direction of the energized voltage.

The factors on which back EMF rely on entail the following:

• Number of turns present in stator windings
• The angular velocity of the rotors
• Magnetic fields produced by the rotor magnets

How Does A Brushless DC Motor And An Induction Motor Compare?

Here is how these two compare:

• Torque Or Speed Traits

Brushless DC motors have a flat characteristic enabling their operation at any speed with a rated load. Induction motors have non-linear characteristics enabling them to achieve lower torque levels at a lower speed.

• Slip

In a brushless DC motor, you will experience no slip between the frequencies of the rotor and stator. The rotor operates at lower frequencies than the stator through the slip frequency within induction motors.

Besides, the slip will increase with the load on induction motors.

• Initial Current

There is no requirement for unique starter circuits in brushless DC motors due to rating of the starting current. However, induction motors have an average of seven times the starting current.

Furthermore, with induction motors, carefully select the rating of starter circuits.

• Output Power

Brushless DC motors have a high output power as it contains permanent motors within the rotors. This allows it to achieve a smaller size for specific power output.

Induction motors have a moderate power output as windings are both in stator and rotor. Besides, they have a lower power output size than brushless DC motors.

• Control Needs

A brushless DC motor needs a controller to ensure the motor continues to operate. Besides, you can use the controller to ensure variable speed control.

Induction motors require no controller at a fixed speed. Besides, you will require the controller if you need to achieve variable speeds.

• Inertia Of Rotor

Brushless DC motors have low rotor inertia thus have suitable dynamic traits. Induction motors have high rotor inertia thus contain poor dynamic traits.

Figure 6 BLDC Motor Vs. Induction Motor

What Are The Handling And Storage Requirements Of A Brushless DC Motor?

The motors are sometimes made using rare earth magnets that necessitate careful handling procedures. Besides, one may experience injury or the motor may fail if you handle it incorrectly.

Ensure the bearings are permanently lubricated to ensure proper operation. If the motor contains magnetic assembly within the armature due to size and weight, leave it this way to ensure no damages occur.

What Are Some Control Mechanisms Available In A Brushless DC Motor?

These include the following:

• Sensor And Sensorless Control

A sensored brushless DC motor contains positional sensors that relay feedback to controllers. This ensures that drive patterns synchronize perfectly with the position of the rotors.

Sensorless brushless DC motors contain no built-in sensors. To operate efficiently, they need sensorless brushless motor controllers.

• Open And Closed-Loop Control Speed

Open-loop entails controlling the applied DC voltage to the terminals by cutting DC voltage. However, this may cause limitations on the current.

A closed-loop entails the control of input voltage supply via speed feedback coming from the motors. This means you will control the supply voltage by relying on error signals.

• Intelligent Phase Control

This system will adjust the phase of the motor voltage and current automatically.

• Field-Oriented Control

This system describes how to control speed and torque relying on the state of the electromagnetics within the motor.

How Does Brushless DC Motor And AC Motors Compare?

• Brushless DC motors get energy from batteries, cells, etc. while AC motors get it from the main power supply.
• AC motors can operate on single and three-phase supplies while brushless DC motors can operate on single-phase supplies.
• Brushless DC motors are self-starting while AC motors are self-starting for three-phase while single-phase requires a starting system.
• Three input terminals are present in AC motors while two input terminals are available in brushless DC motors.
• Depending on the setting, a brushless DC motor achieves higher revolving velocities than AC motors.
• Besides, brushless DC motors are highly efficient than AC motors.

How Many Types Of Brushless DC Motors?

These include:

• Inner Rotor

Here, the rotors are within the stator with segmented permanent magnets outside the rotor surface.

• Outer Rotor

Here, the rotors are outside the stator with the permanent magnets within the rotor.

The segmented permanent magnets are within the rotor’s internal surface.

• Disk Rotor

In this setup, the magnetic pole sensors and windings are mounted to form the stator on circuit boards. This rotor is thin as the tabular permanent magnets are on the surface of the rotor, making them appear thin.

Figure 7 Types of Brushless DC Motor

The Controllers Of Brushless DC Motors Come In What Circuit Designs?

Common brushless DC motors controllers contain a half-H bride or a half-bridge circuit.

The circuit configurations contain two switches. These are the low-side and the high-side transistors.

A majority of brushless DC motors employ triple or double phase power systems.

Figure 8 H-Bridge BLDC Motor Circuit

What Challenges Will You Encounter When Making The Controller Of A Brushless DC Motor?

Brushless DC motor controllers in power electronics encounter high voltage and current thereby needing a high switching frequency.

Also, the accuracy of the position of the rotor is a challenge that you can achieve using sensorless or sensor measurements.

Besides, the primary programming challenges depend on the firmware development of the microcontrollers.

Brushless DC Motor Have What Characteristics?

1. Torque will increase when the speed slows down.
2. A large current flow may demagnetize the magnetic forces of the motor’s permanent magnets, causing windings to overheat and burn out.
3. An increase in speed decreases torque, thus lowering necessary torque load making it unsuitable for use.

How Does Slotted Stator And Slotless Stator Motors Compare In Brushless DC Motor?

The coils will wind in separate external operation in a slotless motor whereas, it winds within the slots in slotted stator motors.

Figure 9 Slotted Motor Vs. Slotless BLDC Motor Construction

What Are The Limitations Of A Sensorless Brushless DC Motor Controller?

There is no generation of back EMF when the rotor in the motor is not turning. Lack of back EMF causes the drive circuits to lack the data necessary to properly control the motor.

Figure 10 Sensorless BLDC Motor Circuit Design

Further Reading:

DC Motors

Brushless DC Electric Motors

BLDC Electric Motors

For any questions or inquiry about brushless DC motors, contact us now.