Expert AC Brushless Motor Manufacturer in China

With any small motor you need, Longbank has it all! Longbank, together with our expert technical engineers, can provide AC brushless motor with great quality and high performance. We have been in the industry for over 20 years. Therefore, we can be the best partners!

Please send us your specific small motor requirements, let our expertise satisfies you!

AC Brushless Motor

Longbank is the leading China-based manufacturer that will give you world-class quality AC brushless motors. We are keeping on developing an extensive line of AC brushless motors in different models. We can produce an innovative series of small motors to meet your application needs with our rich knowledge and skillful engineers. You can always count on Longbank for your custom Ac brushless motor requirements!

About Longbank Motor

Longbank has been a premier small motor supplier and manufacturer for over 20 years now. After over two decades of dedication, we can produce different models of DC motors, induction motors, brushless motors, RO pump series motors, and many more.

Longbank, with our years of dedication, allows us to provide exceptional small motors, especially the AC brushless motor. Anytime you need our products, you can always depend on us!

Brushless DC Motor manufacturer

AC Brushless Motor Manufacturing Expert

electrical motor manufacturing in factory
custom electrical motor factory

Longbank owned automated manufacturing lines, rigorous testing equipment, and innovative technology to manufacture your required AC brushless motor and other small motor demands. Through this process, we can guarantee consistent performance and reliable quality of every motor we offer.

Let Longbank to help you skyrocket your business with our AC brushless motor at a more competitive price.

More About Longbank AC Brushless Motor

For more certifcation and patent, you can check here.

Longbank AC Brushless Motor

Longbank is a 22-years expert in AC brushless motor production industry. We are a China-based factory, providing you an excellent quality line of AC brushless motors to suit your application needs.

If you need a great-performance AC brushless motor for your business projects, Longbank has almost all models to offer. We offer various AC brushless motors with different gears, variable-speed, slow, reversible speeds, and many more.

What’s more, Longbank AC brushless motor is a brush motor that uses a commutator and brushes to provide electricity to magnetic coils on the architecture.  This process creates a loss of energy, heat, and friction. Indeed, Longbank will be your best partner if you need our line of AC brushless motors.

Longbank AC Brushless Motor Features:

  • Robust and durable construction with a hollow shaft smooth integration
  • Star winding uses for keeping up torque delivery even at slow rotation rates
  • Brushless commutation reduces friction-inspired power losses, guarantees spark-free and noiseless operation, and better motor controllability.
  • The AC synchronous subtype supplies smooth rotation without extravagant noise, cogging, or electromagnetic intrusion.
  • With rare-earth magnets and a basic inrunner, the design enables achieving ultra-high efficiency in firm dimensions.
  • Excellent torque density, power-to-mass ratio, less trouble with maintenance, enhanced efficiency, etc.
  • Temperature-sensing components constructed into the rotor coils spots overheating to stop demagnetization.
  • An optimal airflow system like a rear fan that competently cools the motor for extra durability

You are sure to get the exact AC brushless motor you need for your specific applications at Longbank. Depending on your project needs, we present our broad line of AC brushless motors for you. It is certified to ISO, UL, CE, 3C, and more.


  • Increased efficiency creating more torque per watt
  • Reduced noise
  • Increased reliability

As a fully certified company, we keep on adhering to a strict quality control administering system. We owned all testing equipment to test all products’ quality. The testing process also ensures detect-free, safer, and reliable motors.

Please discuss with us your specific AC brushless motor needs. Contact us without hesitation!

 The Ultimate FAQ Guide

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

It is because this guide covers everything about AC brushless motors – so keep reading to learn more.


What Is Torque Ripple In AC Brushless Motors?

Figure 1 AC brushless motor

Figure 1 C brushless motor

Torque ripple is generated in the same manner as the current flowing through a wire creates a force near a magnetic field.

The angle formed between the magnetic and current vectors should ideally be 90°.

However, other factors come into play that influence the actual angle to fluctuate around 90° by a small percentage.

The Torque Ripple is found in the AC Brushless Motor but its degree varies from other motors based on design and drive used.

Zero Torque can also be achieved but with other motors beside AC Brushless Motor like the Brushless DC Motor using drive.

Practically, factors that prevent achievement of Zero Torque include the winding variations, drive offset voltages and mechanical tolerance.


What Are The Benefits Of AC Brushless Motor?

  1. Reduced Noise

They have a very soft start and stop mechanism with a resistance to any vibration or bumps. Brush friction loss noise is eliminated with no sparks hence minimal noise.


  1. Reliable and Efficient

By eliminating the wear and tear experienced in conventional motors, power loss is reduced and efficiency increased. This is because there are no brushes to rub against any rotating metal contact.


  • Maximum Performance

The AC Brushless Motor has outstanding mechanical properties with a wide range of speed. This allows for stepless regulation of speed with position control offering efficient performance and cycle time.


  1. Flexible Control

Controlling the motor can be easily done using a fieldbus, analogue and digital inputs or using direction. It can also be incorporated into an existing concept of control with an option of stand-alone operation.

Figure 2 AC brushless motor

Figure 2 AC brushless motor

How Do You Dry Test AC Brushless Motor?

When an AC Brushless Motor overheats or has experienced some form of physical damage, it has to be dry tested.

This is on order to find out with it has any operational problems.

The steps involved in dry testing an AC Brushless Motor are:

  • Step One

The motor is first disconnected from the mains and the Electronic Speed Controller. It is then wound up with a battery operated variable speed drill while isolating the three lead wires and holding the stationary part.

Observe if strange noises emanate from the motor or the AC Brushless Motor starts heating up from the inside. This shows that either a winding has been shorted or the stator is being hit by a lose magnet within the motor.


  • Step Two

The three motor wires are labeled as 1,2 and 3 making sure they remain isolated from each other. A voltmeter is then connected to the AC range and two of the wires connected to terminals 1 and 2.

The drill is then wound at full speed once more and the AC voltage noted. The process is repeated with terminals 2 and 3 and 3 and 1.

The AC Brushless Motor is considered to have a problem if the three readings are not almost the same.


  • Step Three

Establish if there are shot circuits between the AC Brushless Motor windings and the stator. Inspect whether there is any connection between the stator laminations of the motor and the windings.

One meter connection should come from the stator where there is bare metal and the other from the meter windings. The steel lamination coating can be poked through the steel lamination coating to find a contact on the windings.

The meter should read an open circuit otherwise the motor is most likely shot.


  • Step Four

If the AC Brushless Motor has passed the above tests, then it is still fully operational. Before operating it, the no-load current has to be checked first and compared to the manufacturers specifications.

This helps in identifying any shorted turn or a shorted winding in the motor. The motor cannot be used since it will generate extremely high temperatures and damage it further.


What Are The Components Of An AC Brushless Motor?

The AC Brushless Motor has the following components:

Figure 3 Parts of AC brushless motor

Figure 3 Parts of AC brushless motor


The stator is made up of laminations of stacked steel that has windings placed in slots that are embedded in the laminations. It is similar to the one used in ac motors but with a difference in windings.

The Brushless DC Motor contains three stator windings connected in either delta or star configuration. Various coils are connected to the windings together to form a winding.

There are two major starter winding types namely trapezoidal and sinusoidal. Their difference occurs in the interconnects of the starter winding coils which give different back-EMF types.

The trapezoidal type has its back-EMF in a Trapezoidal shape. The sinusoidal variation on the other hand generates a back-EMF that equals the motors current.



It is composed of permanent magnets with poles varying between two to eight.

The magnets are attached to the core of the rotor with the north and south pole fields alternating.

Ferrite magnets are used to make permanent magnets in rotors. Rare earth magnets can be used in the event that higher power density is required.

Higher power density enables the Brushless DC Motor to generate more torque per unit volume. This is an advantage to manufacturers who are force to produce smaller unit packages.

Figure 4 Back emf in electric motors

Figure 4 Back emf in electric motors

How Does The Back EMF Affect Performance Of AC Brushless Motor?

The back Electromotive Force is an electromagnetic induction-related occurrence. This happens when a certain voltage quantity passes through a conductor and opposes the current applied.

The rare-earth magnets used in the AC Brushless Motor contain crystalline alloys with rare earth elements. With an impeccable magnetic anisotropy, the attraction force delivered by the magnet is twice ferrite magnet force.

This produces a very strong magnetic field. The AC Brushless Motor has trapezoidal configured windings which generate an EMF that is trapezoidally shaped.

Figure 5 Trapezoidal back emf

Using the sinusoidal winding pattern, sine-shaped EMF waves are produces by the AC actuators. This enables them to have a very smooth rotation in the process greatly reducing the torque ripple.

The major shortcoming is that the sinusoidal control is more dependent on complicated algorithms compared to trapezoidal one.

Figure 6 Sinusoidal back emf


The Brushless AC motor’s trapezoidal configuration is linked with extensive electrical and audible noises.


How Does An AC Brushless Motor Work?

An electric current is used to generate a magnetic field that alternates by attracting and repelling a different set of magnets.

This current is required to by the rotor to generate a torque which brings about the AC Brushless Motor spin.

The current is produced by electromagnetic induction obtained from the stator winding’s rotating magnetic field. The rotor can either be a wound type rotor or a squirrel cage rotor.


What Are The Limitations Of AC Brushless Motor?

The various challenges in manufacture of an AC Brushless Motor include:

  • Constant Power Range is Limited: a high motor efficiency can only be achieved with power range that is constant and large. AC Brushless Motor with permanent magnet cannot reach speeds higher than two times the base speed.
  • High-Speed Performance: permanent magnet motors which are surface-mount cannot reach maximum speeds required. The assembly’s mechanical strength between the permanent magnets and the rotor yoke inhibit it.
  • Magnet Demagnetization:high temperatures with high reverse magnetomotive force can easily demagnetize the permanent magnets. Each permanent magnetic material has a different demagnetization force.
  • Cost:compared to normal magnets, rare earth permanent magnets are really costly. This increases the eventual cost of the final AC Brushless Motor.
  • Complex Structure:the use of position sensors provides an easy method of detection compared to complex control algorithms. However, incorporating them complicates the structure arrangement of AC Brushless Motor and increases its maintenance.
  • Back Electromagnetic Force: the speed of the motors rotor is directly proportional to the back EMF. This means that running the AC Brushless Motor at low speeds reduces its positioning accuracy.


How Do Different Windings Of AC Brushless Motor Affect Its Parameters?

The exchanging of volts to amps in an AC Brushless Motor is called Winding Scaling.

An increase in the stators number of wire turns leads to a voltage drop increase across the windings.

This in turn leads to a decrease in the rated current.

When a winding has been scaled, the motors power remains the same but changes occur on the torque and maximum speed for a certain current.

The more the number of turn counts, the lower the motors speed of rotation.

The higher the number of turn counts, the higher the motors speed of rotation.

Figure 7 Types of winding

Is An AC Brushless Motor Faster Than Brushed Motor?

An AC Brushless Motor is a kind motor containing no brushes as in its parts. If a brushed motor and an AC brushless one have similar ratings, the brushless one is faster with a higher efficiency.

This is because friction in the Brushless AC motor is almost eliminated and therefore reducing the amount of heat generated.

Optimum power is thus used in unlike in the brushed motor where speed relies on the commutator and brushes.

How Does AC Brushless Motor Compare To DC Brushless Motor?

Within the class of Brushless Motors, bot DC Brushless Motors and AC Brushless Motor can be distinguished using synchronous actuators.

They have a striking resemblance like having rare-earth (Ferrite) magnets on their rotors.

They also both have a stator does not contain the commutator assembly or brushes on it.

Both DC Brushless Motors and AC Brushless Motor are synchronous meaning the rotor and stator magnetic fields have identical velocities and frequency.

The main difference is that their stators have different winding patterns. This means that their electromotive force profiles differ.


How Does An AC Brushless Motor Function Without Sensors?

Bearing in mind that some AC Brushless Motors don’t have in-built sensors, the motor controller has to function without them.

One way this can be realized is by utilizing the motors back EMF to dynamically monitor the position and speed of the rotor.

The back EMF is simply described as the voltage that the AC Brushless Motor creates (acting as a generator).

This motor in a way is similar to a generator hence when driven it will produce an electromagnetic force.

The EMF counters the forward voltage generated by the driver with focus being on the force of frequency.

The frequency force is linked directly to the rotor speed and can be measured by an intelligent brushless motor controller that is Sensorless.

Measurements taken using the back EMF frequency makes it possible for the motor speed to be measured.

This speed is then compared to the speed that is aimed at by the brushless controller with discrepancies adjusted via closed loop system.


 How Much Noise Is Expected From A running AC Brushless Motor?

It is common to encounter some form of high frequency noise when a permanent magnet closes the feedback loop in an AC Brushless Motor.

Some of the factors that influence the amount of noise include:

  • Gains in the PID
  • Resolution of the Encoder
  • Whether filtering has been applied or not
  • The drive chip’s fidelity

If any of the above factors is adjusted, then the audible noise emanating from the motor can be reduced significantly.


 What Are The Types Of AC Brushless Motors?

AC Brushless Motors can be classified into two depending on where the rotor is placed. They are:

  1. Inrunner Motor: the design has the rotor placed internally with stator outside the motor (rotating element). They function well at very high speeds but with lesser torque generated due to reduced diameter.

Their advantages include:

  • Highly efficient
  • Relatively small in size
  • Very big power density
  • Can operate continuously for a very long time


  1. Outrunner Motor: the rotor is placed outside the motor hence the motor’s case spins around the stator together with the permanent magnets. They have a larger diameter hence generate more torque but with a slower spin speed.

Their major advantages include:

  • They have impeccable stability
  • Are structurally shorter
  • Operate well in applications that require constant speed
  • They are more economical

Figure 8 Inrunner vs outrunner electric motor

How Can You Tell If A Motor Is AC Brushless Motor?

While checking out a motor, some points have to be considered to ascertain if it’s an AC Brushless Motor. They are:

  • If the said motor functions without any connection to a controller, then it is considered a brushed motor. An AC Brushless Motor requires a controller for it to operate.
  • An AC Brushless Motor has three windings hence the motor has to have at least three wires. A brushed motor is composed only of two wires.
  • The resistance of the motor is measured by supplying a low voltage through it. An AC Brushless Motor will produce a very high resistance.


How Do Wye Winding Configuration Compare To Delta In An AC Brushless Motor?

Both Wye and Delta configurations enable an AC Brushless Motor to generate equal loads to all the motor’s three phases.

The difference in the use of either occurs with the number of nodes used.

Delta Windings contain three nodes namely A Phase, B Phase and C Phase. The Delta winding schematic connection is triangular while the schematic connection for Wye winding is “Y” or a star.

AC Brushless Motors with low inductance require Wye windings so as to evade current parasitic losses. Such losses are very common in both motors with low inductance and delta windings.

The Wye windings counter this by having the parasitic current circulated therefore allowing greater precise moves working at lower speeds.


 What Are Radial And Axial Runout Errors In AC Brushless Motor?

Runout can be defined as a rotating mechanism’s inaccuracy whereby rotation of an AC Brushless Motor does not take place around the major axis.

It is the dimensional requirement that describes the motion error of a surface moving relative to a datum.

Radial runout

Radial runout occurs when the rotation axis is centered off the main axis but is still parallel to it. It is the roundness of the AC Brushless Motors rotation.

The motors horizontal motion is defined as it rotates in the horizontal plane and is sometimes called lateral translation. The bearing supporting the axis motion is the major contributor to this type of runout.

Radial runout is crucial because the ability to center a part is affected on the AC Brushless Motor.

It’s important because deviation of any point on the rotor axis from its original location will cause undesirable angular error.

Axial Runout

Axial runout occurs when the rotation axis is tilted from the main axis with a certain degree.

This means that the rotation axis does not appear parallel to the main AC Brushless Motor axis.

The rotor position is affected by the part position in the vertical direction.

This is vital because if the rotor has a vertical direction deviation, then no operation can efficiently take place.


Is an AC Brushless Motor Waterproof?

An AC Brushless motor is a motor that does not have brushes as part of its components. Commonly, an AC Brushless Motor can be resistant to water but not necessarily waterproof.

This means that water can still find its way into the motor and eventually into the internal windings and bearings. This destroys the bearings over time with significant damage on the coils too.

Alternatively, an AC Brushless motor can be waterproofed but the downside is the limitation it will bring to its performance. This will also increase the eventual cost of the motor.


What Are The Benefits Of Using Brushless Commutation In AC Brushless Motors?

Some of the benefits of using the Brushless Commutations to run AC Brushless Motors include:

  • The operations of the motor extremely reduced noises with the electromagnetic interference decreased significantly.
  • The weight is trimmed after the commutator assembly is removed,
  • The control logic is complex but the capabilities of regulating the motors motion such as holding torque delivery are extended.
  • The Torque-to-Mass and power-to-mass ratios are greatly improved.
  • The cost of maintenance is greatly reduced because of the absence of wearable parts. Durability is also improved because the bearing life dictates the operating resource.
  • The motor operation is spark free because electro transistors have replaced mechanical commutation. This means that the motor can operate even in environments that are potentially explosive.
  • The motors motion can achieve very high velocities because the rotors inertia is at its minimal.

For all your AC brushless motors, we offer perfect solution for all your needs – contact us snow.

Longbank Brushless Motor

Are you seeking the most reliable Brushless Motor producer and distributor? Longbank is an excellent place for you. We are delighted to provide various Brushless Motor models to different nations around the world. Longbank is capable of meeting all of your Brushless Motor needs at a reasonable price.

It is a direct current (DC) electric motor that does not use mechanical brushes or a commutator like a typical brush motor. It offers great features over a brush motor and is more cost-effective in the long term, despite more significant starting expenses. No brushes are rubbing against; therefore, there is no energy loss from friction. Therefore much more energy-efficient than brushed motors and may last up to 50% longer on batteries.

Please tell us about your idea so we can discover the Brushless Motors that are appropriate for you! Longbank provides unique solutions as a prominent Brushless Motor provider. Please email us your product specifications so that we can get started.

Brushless Motor Advantages

  • It doesn’t have any carbon brushes, which means fewer brush replacements and lower maintenance expenses.
  • It offers more outstanding quality and reliability than brushed motors due to electronic control, which allows for finer control of the motor’s speed and position. 
  • It has a lifetime of roughly 6 times that of brushed motors.
  • It has a lower risk of burnout due to sparking difficulties because there is no spark.
  • Because it has a low no-load current, You can use it at low or no load.
  • It is capable of constantly providing maximum torque throughout the rotation.
  • It may include a feedback control system for monitoring and controlling the speed and torque.

You may rely on Longbank as a skilled Brushless Motor manufacturer. BL4835, BL6324, BL7125, BL10045(Low Voltage, OBL5020, OBL6425, and OBL7527 are some of the Brushless Motor models we may supply based on your requirement.

Our firm employs a competent and skilled workforce. We oversee every step of the procedure, from a selection of materials to manufacturing to shipping. Longbank also uses automated manufacturing lines, testing equipment, and cutting-edge technologies to ensure high-quality and consistent Brushless Motor performance.

Our primary goal is to provide you with high-quality Brushless Motors. As a well-certified manufacturer, we will assist you in finding the perfect motors for your business. Whether you have a small or large purchase, we will do our best to meet your needs.

For additional information, don’t hesitate to get in touch with us!



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