Basic introduction of drone motor - How to read a motor

In a drone's flight system, motors play a key role because they directly power flight. The performance of the motor not only determines whether the UAV can successfully take off, hover, land and move flexibly, but also has an important impact on its overall flight time and stability. If the power of the motor is insufficient, the flight speed and height of the UAV will be limited, and the flight time will be shortened. Therefore, choosing a motor with high efficiency and high power is crucial to the performance of the drone.

 

 

1. The structure of the drone motor

The motor of the drone is mostly brushless motor design. The brushless motor is generally composed of nut, rotor, double bearing, stator, washer, base and locking screw and other components, which is compact and highly precise. Specifically, the rotor part contains the magnet, shaft and housing, while the stator is composed of silicon steel sheet and enameled wire. This design not only guarantees the high power output of the motor, but also improves the stability and durability of the motor.

 

Take VSD's motors as an example, which feature a robust titanium/aluminium alloy housing and are equipped with high quality 48SH/N52H curved magnetic steel and imported NMB bearings for extremely high durability. In addition, VSD motors use military-grade heat-resistant coils to ensure stability in high temperatures and severe vibrations. The 0.2mm thick silicon steel sheet structure used inside the motor effectively reduces the heat of the motor and improves the overall efficiency and durability of the motor, making it still perform well in long-term flight missions.

 

2. drone motor sizing

When picking a drone motor, the size of the motor is usually indicated by "2206", "2306" and other model identifiers. The motor model is composed of four digits, the first two digits indicate the diameter of the stator coil (unit: mm), and the last two digits indicate the height of the stator coil. For example, the 2206 motor has a stator with a diameter of 22 mm and a height of 6 mm. This dimensional coding method is suitable for almost all brands of external rotor motors and helps users quickly understand the physical specifications of the motor.

 

VSD's extensive product line of drone motors supports the selection and customization of various specifications, including 2206, 2207, 2208, 2806, 2807, 2810, 2812, 3110 and 3115. Users can flexibly choose the right motor model according to their needs, and VSD also provides customization services to ensure that the motor is perfectly adapted to the specific application scenario of the UAV.

 

 

 

3. KV value of the drone motor

KV value is one of the important parameters of brushless DC motor. The KV value (unit: RPM/V) indicates the speed that the motor can reach with every 1V voltage applied under no-load conditions. For example, an 880KV motor will reach 880 RPM when 1V is applied with no load. This value can help users understand the relationship between the speed of the motor and the voltage, and choose the right motor according to the application needs of the UAV.

 

The smaller the KV value, the lower the motor speed is lower, but it can withstand higher voltage, so it is suitable for scenarios requiring greater torque and can drive larger diameter propellers. And the higher KV motor has a higher speed, suitable for driving small size, fast rotating propellers. VSD offers a variety of KV value options, including 900KV, 1350KV, 1750KV and 2400KV models, to meet different needs from high speed light load to high torque load.

 

4. Drone motor coil turns

The number of coil turns of the motor is identified as "9T", "13T", etc., on some motors, indicating the number of turns of the stator winding. The number of turns is closely related to the KV value, usually the number of turns of the motor winding with lower KV value is less, and the wire is thicker, which is suitable for driving large-size propeller at low speed; And the motor with higher KV value has more turns and thinner wires, which is suitable for driving high-speed small propeller.

 

The number of motor winding slots of VSD can be customized according to customer needs, the more slots, the higher the efficiency of the motor, especially suitable for dealing with the requirements of complex flight scenarios. Of course, the higher number of slots may bring higher manufacturing costs, but the improved motor performance is often worth the money for demanding applications.

 

5. Drone motor no-load current and voltage

In the no-load test of the drone motor, the current measured when the specified no-load voltage (usually 10V or 24V) is applied is the no-load current. This parameter can help evaluate the efficiency and energy consumption of the motor. The lower the no-load current, the less energy loss of the motor and the higher efficiency, which helps to extend the endurance of the drone. VSD's motor is excellent in no-load current and efficiency, and can meet the needs of different applications, especially for the pursuit of longer endurance and stability of the UAV application scenario.

 

6. Maximum current and power of drone motor

Drone motor needs to consider the maximum current and power to withstand when working. The maximum current or power refers to the limit that the motor can withstand without damage. For example, a maximum continuous current labeled "16A/180s" means that the motor can operate continuously at 16A for 180 seconds without being damaged. Beyond this value, the motor can overheat or even be damaged, so it is necessary to ensure that the current is kept within a safe range in practical use. VSD's motors perform well in maximum current and power tolerance, making them suitable for applications requiring long periods of high-load flight.

 

7. Internal resistance of drone motor

There is an internal resistance in the armature of the motor, although the value is usually small, but in the drone motor with a current of dozens of amps, the impact of this internal resistance cannot be ignored. Due to the existence of internal resistance, part of the electrical energy will be converted into heat energy, making the motor hot and resulting in reduced efficiency. Therefore, the reasonable design and control of the current is essential to maintain the high efficiency of the motor and prevent overheating.

 

To solve this problem, VSD motors pay special attention to heat dissipation design. The motor shell is made of titanium/aluminum alloy with high thermal conductivity, which effectively improves the heat dissipation efficiency. In addition, the motor structure of the VSD adopts a porous ventilation design, which further helps the motor to maintain a low temperature under high load, improving the efficiency and service life of the motor.

 

8. drone motor performance parameter table

The performance parameter table of the motor can help users understand its efficiency, power and thrust indicators more clearly. Efficiency (unit: g/W) is a commonly used performance evaluation standard, which indicates the thrust generated per watt of electrical energy. These data can provide a reference according to the different working conditions of the motor, and the designer can choose the appropriate combination of motor and propeller to ensure the best performance of the UAV.

 

Electric power (W) = motor input voltage (V) × effective current (A)

 

Motor efficiency = Mechanical power (W)/electrical power (W)

 

It is important to note that motor efficiency is not fixed and will change as the input throttle and load (propeller) change. For the same propeller, when the input current increases, the heat and other energy loss will also increase, the proportion of mechanical power will decrease, and the motor efficiency may decrease accordingly. Therefore, reasonable motor and load matching helps to improve the overall performance of the drone.

 

VSD is well aware of customers' demand for motor performance data, and each motor is thoroughly tested with advanced test equipment and provides detailed performance test sheets. This kind of data provides a scientific basis for customers to choose the right motor type and configure the propeller, ensuring the efficient application of the motor.

 

 

The basic working principle of the brushless motor is to use the interaction between the magnetic field generated by the current flowing through the coil and the permanent magnet to drive the rotor to rotate. Specifically, the magnetic effect will be generated after the current passes through the stator coil, and the force of same-sex repulsion and opposites attraction will be generated with the permanent magnet in the rotor, pushing the continuous rotation of the motor.

 

Since the stator is fixed, and the permanent magnet of the rotor needs to be constantly rotating, the brushless motor changes the magnetic field by changing the direction of the current, so as to drive the rotation of the rotor. For the three-phase brushless motor, the three-phase bridge circuit connection is usually used, and the control mode of "two two on" is adopted. That is, when the motor rotor rotates 120 degrees, the switch tube in the inverter carries out a commutation, so that the stator's magnetic field direction changes, so as to continue to promote the rotation of the rotor.

 

VSD's brushless motor uses a precision control design to ensure accurate and efficient current switching during rotation, thus providing smooth power output. This control method not only improves the motor response speed, but also maintains high stability and reliability in complex flight scenarios.

 

 

Founded in 2011 and headquartered in Shenzhen, China, VSD is a professional micromotor manufacturing enterprise integrating research and development, production and sales. The company is committed to providing the market with high quality, high performance motor products, its main products cover precious metal motor, carbon brush motor, gear motor, brushless motor, hollow cup motor, wheel motor and DC pump, air pump, solenoid valve and other motor types. With advanced production technology and strict quality management, VSD products have been exported to Europe, America and Southeast Asia and other countries and regions, widely by Kautex, Panasonic, Philips and other international well-known enterprises favor and trust.

 

VSD always adhere to high standards of quality requirements of its products, has passed CE, REACH, ROHS, IATF16949 and other international certification, and won the national high-tech enterprise certification. The company invests 2.6 million yuan in research and development every year, and launches a new motor every two months on average to meet the changing market demand. The factory covers an area of more than 10,000 square meters, with more than 500 front-line employees and more than 100 management personnel, including 25 R & D personnel, with a monthly output of 4.5 million units of motors to ensure the stability of product supply and high efficiency of delivery.

VSD provides factory direct sales, relying on the advantages of origin and efficient production process, products have a significant competitive price, and reliable quality. For customers with customized needs, VSD also provides professional OEM and ODM services, which can be customized according to the specific needs of customers. At the same time, VSD invites customers to visit the factory to learn more about its production equipment and process flow. You are welcome to make an appointment at any time.

 

Through more than ten years of industry accumulation and technology precipitation, VSD has always been committed to innovation and quality, continue to provide customers with high-quality and reliable motor products and solutions, and become a trusted motor supplier in the global market.