Solutions to the Common Noise and Vibration Problems of Motor

Mechanical reasons.

1. The motor wind blade damage or fasten the screws of the wind blade loose, resulting in the wind blade and the wind blade cover touched, it produces sound with the lightness of the sound of the touch, sometimes big and sometimes small.

2. Due to bearing wear or shaft improper, resulting in motor rotor eccentricity severe cases will make the stator, rotor friction, so that the motor produces violent vibration and uneven friction sound.

3. The motor is used for a long time, resulting in the ground screws loose or the foundation is not secure, so the motor produces abnormal vibration under the action of electromagnetic torque.

4. Long-term use of the motor due to the lack of lubricating oil in the bearings formed in the grinding operation or bearings in the steel ball damage, so that the motor bearings in the room issued by an abnormal hissing sound or grunt.

Electromagnetic causes.

5. The normal operation of the motor suddenly appeared abnormal sound, when running with a load speed dropped significantly, issued a low edge of the roar, may be three-phase current imbalance, overload or single-phase operation.

6. Normal operation of the motor, if the stator, rotor winding short-circuit failure or the squirrel cage rotor broken bars will be issued by the motor high and low weng weng sound. The body of the motor will also vibrate.

I. Asynchronous motor to reduce electromagnetic noise.

1. Reasonable selection of air gap magnetic density.

2. Selection of the appropriate winding form and number of parallel branch circuits.

3. Increasing the number of stator slots to reduce the harmonic distribution factor.

4. Suitable slot fits.

5. Utilizing magnetic slot wedges.

6. Rotor slant groove.

II. For the products that have been produced with high electromagnetic noise.

1. Increase the moment of inertia of the seat section appropriately to avoid the resonance area.

2. Synchronous convex pole machine can be calculated to increase or reduce the width of the pole shoe to improve the distribution of the magnetic field, so that the fundamental wave is closer to sinusoidal wave, so as to reduce the high harmonic component, to reduce the effect of electromagnetic noise.

3. Choose more appropriate stator winding wiring rotation number, can effectively reduce the motor winding generated by the reversal wave, thus reducing noise.

4. For the tooth harmonic content is high, can use the magnetic groove boots.

III. Newly designed motors.

1. Choose the right number of grooves to match.

2. Selection of appropriate pole spacing; and

3. Increase the number of parallel branch circuits; and

4. Convex pole machine, to choose the appropriate width of the pole shoe.

5. In the case of motor performance guarantee, appropriate reduction of air gap magnetism.

6. Through the process to ensure the concentricity of the stator and rotor, so that the single-sided magnetic pull tends to zero.

The main contradiction of electromagnetic noise of the motor is stator-rotor slot fit, rotor slant groove and stator-rotor concentricity. Noise reduction measures are mainly the selection of high-quality stator-rotor slot fit and reasonable rotor slant slot width, while making the motor air gap as uniform as possible.

Electromagnetic noise can not be completely eliminated, for any motor is; the key is a degree (value), some people or customers are almost crazy about this, listening to the noise almost hate to drill into the motor inside to go; the noise of the motor exceeds the standard, that is not allowed.