In life, our summer is inseparable from the cooling fan, thenCooling fanHas anyone ever wondered how his motor works when it is running? The fan motor is the function of generating force and force.
In physics class, I talked about the conversion of force and electrical energy. Below with professional knowledge to share with you!

Let's divide it into the upper, middle and lower volumes.

It is divided into five chapters.

Chapter One: Motor Overview

Chapter 2: Principle of Motor Operation

Chapter Three: Motor Controlled Drive

Chapter 4: Motor Performance

Chapter 5: Motor Other

Chapter One Motor Overview

Motor definition: refers to an electromagnetic device that realizes the conversion or transmission of electric energy according to the law of electromagnetic induction.

Note: 1. motor design knowledge of a wide range of fields, including electromagnetics, mechanics, thermodynamics and materials science, it is very important to find the best design at a very low cost. The motor design process is extremely cumbersome, and it is necessary to constantly check whether the design aging parameters meet the requirements.

2. Motor application requirements size and load requirements of the decision, the main size refers to the volume of the motor, in general, the motor volume is proportional to the output power. The load demand includes rated speed, rated output power and ear voltage, and the determination of these parameters is related to the use of the motor.

Cooling fan DC brushless motor

Brushless tributary motor with non-contact position detector and semiconductor components replacement power, transfer flow to achieve motor operation, eliminating the brush-type life name problem, to achieve high performance.

Chapter Two Operation Principle of Cooling Fan Motor

From the time VCC is energized, it is known by the left-hand rule that the magnetic field repulsion makes its motor run.

Chapter 3 Motor Control and Drive

On an energized semiconductor sheet, a magnetic field B plane perpendicular to the surface of the sheet is applied, and a voltage will appear in the transverse second measurement of the sheet. This phenomenon is the Hall effect. (Discovered by scientist Edwin Hall in 1879)

Hall devices, such as the Hall used in cooling fans, have 277 276 177 101 driver chip LB11867 11961. However, with the progress of social science and technology, the current drivers are all written by MCU instead of the original driver chip 11867.

Chapter IV Motor Performance

1. Supply voltage:

Our common voltages are: 5V 36V 48V 18V 12V 3V 24V (less than 36V is the full voltage, more than 36V must pass 3C compulsory certification). Measurement method: multimeter

2. Rated torque:

Generally speaking, it is the size of the rotational force (unit: kgcm N.M ), which directly determines the speed of the cooling fan. The test method used to be too complicated, but now it can be tested with instruments.

3. Rated speed:

The speed of operation per minute. (Unit: n/min RPM).

Generally, the error of 10% for customers can be controlled within 5%, except for special requirements, and now the error can be controlled within 2% through MCU.

Test method: infrared speed converter, internal flash frequency converter, test according to FG waveform instrument

4. Rated current:

Current consumed during operation, coil impedance directly affects current: I = U/R, unit: A mA

Measurement mode: ammeter, now convenient for direct display on DC power supply.

5. Starting torque,

It refers to the force at the moment of starting, which is determined by the starting voltage. Generally, it is less than 1/1.6 of the rated torque.

6.FG/RD Waveform Output

7. Insulation stage and insulation resistance

Insulation resistance (JEC-146)

After the motor is assembled, the insulation endurance test is carried out, and the power frequency sine wave AC voltage is applied to the motor.

Apply a 500 of 2E(E = 50V below the motor voltage) between the coil and the iron core for 10 minutes.

Note: Power off after 250V, 500V and 250V.

Insulation resistance:(JEC-37)

In order to ensure the insulation strength between the motor impulse part and the earth, it is measured with a 100V insulation resistance meter.

Try. More than 0.5M OK, AC more than 1M. 500/rated output 1000 = insulation impedance 0.

8. Cooling fan noise

Noise is that there is no sound without sound, usually in decibels (dB).

The test method has two distances of 1M and 0.5M according to the standard. Usually dozens of dB.

Our condition:(ISO 7779 ISO 3745)

Axial direction of semi-silent chamber: FAN axial distance 1m

Action time: 10 sec

Measure three times and take the largest value.

9. Temperature rise

Temperature rise refers to the difference between the motor temperature and the ambient temperature.

Including operating temperature rise and locking temperature rise.

Measurement methods: thermometer, resistance method, temperature display products, optical method.

The temperature of the parts that can be contacted when measured must be high. Usually we run for a few hours and measure

Lock solid is 24H after the data. Class A at our UL application.

Standard:(JIS C 4003)

And 90 °C

  A  105°C

E 120°C

  B  130°C

  F  155°C

  H  180°C

C more than 180 °

10. Use temperature and humidity

Cooling fan general customer requirements in -10 C ~ 60 C, we strengthen to -40 C ~ 85 C.

Humidity is generally required to be 65% relative humidity, and we have 95% relative humidity at 60°C.

This condition is limited to the use of computers and other equipment for skiing on the Tibetan Plateau and swimming in the Mediterranean.

Relative humidity:

It refers to the percentage of water vapor in the air that reaches a large capacity at the temperature at that time. The water vapor in the bathroom just after taking a hot bath is already saturated. At this time, the relative humidity is 100%, so water droplets condense out in the mirror. The relative humidity in summer is generally very high (often above 80%).

11. Vibration

Shock resistant using a dedicated test platform.

Our test is set to [CNS5076(C6051)]

Displacement 0.75mm

Frequency range

1. 10Hz ~ 55Hz / 30 seconds

2. 55 Hz ~ 10Hz / 30 seconds

3. Linear scanning/120 back/X, Y, Z axis

Impact resistance (IEC68-2-27)

Condition: Half chord wave

Acceleration: 50G

Axial: x , -x , y , -y , z , -z

Action time: 11ms

3 impacts in each axial direction, 18 impacts in total.

12. Life Name

For cooling fans, it mainly depends on the service life of the bearing.

B is 7~90000 H,

C is 3~40000 H

S is 2~25000 H,

T is 45000 H

There are two ways

1. Tighten the test conditions, shorten the test time, and then calculate the life name according to the formula, which is the so-called life name acceleration experiment.

For example, 9020R will be tested according to 1732H.

2. Let the fan run at the standard (25 degrees, 65% relative humidity) for the time recorded by the bad standard.

Accelerated experiments are often calculated differently for each company, and the resulting life names vary greatly. So now many manufacturers do not accept. The second item requires a long time period and venue, and it is difficult to implement.

Again, each customer or manufacturer has different criteria for determining bad, which also affects the longevity data. If some of the specified speed is less than 30%, it is bad, and some are less than 10%.

13. Weight, protection mode, running direction, FG pulse number

Weight: is to control the quality of the entire cooling fan

Protection mode: there is automatic return function for each

Direction of operation: clockwise or counterclockwise

FG pulse number: generally one turn two pulses

Chapter V Motor Others

First, know the starting voltage

Starting voltage means the low operating voltage of the fan. It is a characteristic to compare the advantages and disadvantages of the fan. Usually, a fan with a lower static friction coefficient and a Hall IC with a lower operating voltage can make the fan start at a lower electric level.

Factors affecting the fan starting voltage are:

1. Whether the winding design is appropriate

2. Silicon steel sheet hysteresis loss size.

3. Low working voltage of Hall lC

4. The magnification of the transistor is high or low.

5. The magnetizing strength of rubber magnet.

6. The weight of the fan blades.

7. The friction coefficient of the bearing is high or low.

8. The saturation voltage of the transistor is high or low.

9. Whether there is a reverse protection diode

II. Know the dead angle of the cooling fan.

The so-called cooling fan dead angle means that the fan cannot be started according to the specified voltage under certain angles. The test method is to sequentially adjust the poles of the fan before the Hall IC, and then slowly increase the voltage until it starts. If each pole starts before it is less than the specified voltage value, it means it is qualified. If there is a difference between high and low, if the starting voltage exceeds the specified value, it is called a dead angle.

Factors affecting the fan starting voltage are:

1. The magnetization of each pole of the rubber magnet is uneven.

2.HALL IC sensing sensitivity is too poor.

3. Rubber magnet magnetizing magnetic field is too weak.

4.HALL IC position is wrong

5. Mechanical friction is too large

6. Silicon steel sheet angle and material issues

The above is the operation and working principle of the cooling fan motor. For more information, please consult our official website, Shenzhen Jiangshanlai Electronic Technology Co., Ltd., a powerful cooling fan supplier!