When the motor rotates at high speed, it makes an abnormal sound not noise , what is the cause?

Generally speaking, noise is generated when moving products such as motors are running. The noise is divided into two parts, one of which is the noise generated by the normal operation of the product, which is inevitable and impossible to eliminate, and can only be controlled in a certain range by inhibiting or reducing the method, and the specific detection method is to measure the noise decibel value with a noise decibel tester, and calibrate whether it is within the appropriate limit, but this method should be carried out in a silent room, and the surrounding environmental noise can be eliminated, so it is unlikely to be directly applied on the production line. Another part of the noise is the abnormal sound and noise generated by the product in the process of working operation, this part of the noise is generated when the sports product is not running normally, it will directly affect the life and quality of the product, it must be eliminated, if it cannot be eliminated, it should be judged as a defective product or waste product.

There may be the following reasons.

1.When the cage rotor guide bar is broken or the winding rotor winding joint is disconnected, sometimes there is a "hum" sound when it is high and low, the speed is also slowed down, and the current increases, so it should be checked and treated. In addition, the length of the rotor and stator of some motors is not well matched, such as the length of the stator is too long than the length of the rotor, or the bearing hole of the end cover is worn too much, and the rotor produces axial channeling, which will also produce a "buzzing" sound.

2.The end of the stator winding is incorrectly wired, there is a low roar, and the speed also drops, which should be checked and corrected.

It should be the sound of air flow driven by high-speed rotation.

If it is new, it may be that the voltage is not mild and the rotor is unbalanced, and the old one may be due to the bearing.

The causes of abnormal noise of the motor are: bearing failure, loose and falling off of the magnet, axial channeling, rotor sweeping, etc. If the problem of abnormal noise of electric vehicles must be solved as soon as possible.

An electric motor is a device that converts electrical energy into mechanical energy. It uses an energized coil (that is, the stator winding) to generate a rotating magnetic field and acts on the rotor (such as a squirrel cage closed aluminum frame) to form a magnetoelectric dynamic rotational torque. The life of the motor is related to various factors such as insulation deterioration, wear and tear of the sliding part, and dysfunction caused by bearing deterioration, etc., and most of them depend on the condition of the bearing.

The causes of abnormal motor noise are:

1. Bearing failure: If the bearing of the electric vehicle motor fails, it will cause the gap to become larger, the motor will not operate normally, and the abnormal sound will be caused. For this kind of problem, the general solution is to replace the new bearing, which can solve the problem of abnormal noise of the electric vehicle motor.

2. The magnet is loose and falls off: If the magnet inside the electric vehicle motor is loose and falls off, the performance of the motor will decline, and when the motor is running, it will make noise. For this kind of problem, the general solution is to re-bond the magnet, which can solve the problem of abnormal noise of the electric vehicle motor.

3. Axial channeling: If there is channeling in the internal axial direction of the electric vehicle motor, then when the motor is running, it will shake and make noise. For this kind of problem, the general solution is to add an appropriate amount of washer in the axial direction, so that the problem of abnormal noise of the motor can be solved to a certain extent.

4. Sweep the rotor: If the rotor of the motor and the stator are not concentrified, the local gap will become smaller, and friction will occur, causing the sweeping, which will bring the problem of abnormal noise from the motor. In this case, the general solution is to readjust the rotor and stator, and the problem can be solved.

Photo by Chen Fang1) @2019

1. The stator rubs with the troublemaker in the number of revolutions.

2. The rotor blade touches the shell.

3. The rotor wipes the insulating paper.

4. The bearing lacks oil.

5. There are sundries in the motor.

6. There is a buzzing sound when the motor runs in two phases.

Causes and solutions:

1. Check whether the bearing and rotor are deformed, and repair or replace them;

2. Damaged bearings or poor lubrication - replace bearings, clean bearings;

3. Phase-out operation of the motor - check the circuit break point and repair it;

4. Fan blade touching casing - check and eliminate faults.

1. The stator and rotor rub against each other.

2. The rotor blade touches the shell.

3. The rotor wipes the insulating paper.

4. The bearing lacks oil.

5. There are sundries in the motor.

6. There is a buzzing sound when the motor runs in two phases.

Causes and solutions:

1. Check whether the bearing and rotor are deformed, and repair or replace them;

2. Damaged bearings or poor lubrication - replace bearings, clean bearings;

3. Phase-out operation of the motor - check the circuit break point and repair it;

4. Fan blade touching casing - check and eliminate faults.

If it is a three-phase three-phase electrical imbalance, there will be sound, and if the single-phase motor capacitance is not good, there will be sound. Then the bearing is not good, the foundation is not good, there is a sound. From the presence and absence of electricity, you can tell whether it is an electrical sound or a mechanical sound.

There is a stator and rotor with a bad degree of electromagnetic sound is loud but can be used, sweeping the hall (there are foreign bodies or the casing is not centered), sweeping bamboo sticks, sweeping paper, this is not good, the bearing is worn or damaged due to lack of oil, the end cover is not centered and there is friction, and the fan blade is close to the back cover to rub.

The ground is uneven or the feet are not tightly fixed, and there will be a lot of noise...

Answer: (1) Phase-off operation:

2) Three-phase voltage unbalance;

3) Severe bearing wear or lack of oil;

4) Friction between the stator and the rotor;

5) Friction between the fan and the hood or cover;

6) The base is loose.

Those causes the motor to fail to turn and at the same time make a humming sound.

Hello, (1) The stator and rotor windings are broken or the power supply is disconnected in one phase. Identify the breakpoint of the winding or the breakpoint of the power supply phase and fix it. (2) The end of the winding introduction line is connected incorrectly or the winding is reversed.

Medium fibrillation is tested to check the polarity of the winding and judge whether the head and tail ends of the winding are correct; Find out the wrong connection point inside the winding and correct it. (3) The contact of the power supply circuit is loose and the contact resistance is large. Tighten the bolts, check whether the joints are falsely connected with a universal meter, and repair them.

4) The load is too large, or the rotor is stuck. Load shedding or detection and elimination of mechanical faults. (5) The power supply voltage is too low or the voltage drop is large.

Check whether the connection method is connected to the maid connection method, whether the power cord is too thin, the voltage drop is too large, and correct. (6) The assembly of the motor is too tight or the grease in the bearing is too hard. Reassemble to make it flexible and replace it with qualified grease.

7) The bearing is jammed. Repair of macro hole bearings.