Causes of abnormal noise in Pacific Automotive Network car generators: 1. The V-belt of the generator slips; 2. The bearings of the generator are damaged; 3. The rotor and stator collide before; 4. The fan blades and front end Cover collision.
The sound of metal friction is mainly caused by the damage of the bearing, or the friction sound of the bearing sleeve and the casing; the vibration sound is caused by the aging of the bearing, loose foundation, unbalanced rotor, and incorrect connecting shaft. Poor coordination, cracking of the casing, etc.; buzzing noise, general overload, two items, inter-turn short circuit, etc.
If it is a variable frequency motor, the frequency may be too high and the mechanical resonance point cannot be avoided. If there is no frequency converter, you should first determine whether the abnormal noise is from the motor or the mechanical noise driven by the motor. Abnormal noise in the motor may be caused by a broken fan and severe wear and tear of the bearing due to lack of oil. If the rotor shaft of the motor does not rotate but the motor makes abnormal noise, then it is certain that the rotor shaft and the rotor winding (cast aluminum squirrel rotor) are loose.
To distinguish electromagnetic noise, mechanical noise or ventilation noise, the step-by-step operation method is generally used to distinguish, that is, disconnecting a certain moving part to analyze the noise source. For example, the noise generated by disconnecting the fan is electromagnetic noise or Mechanical noise, and then cut off the power supply, if the noise still occurs in the end, it can be determined as mechanical noise.
(Pictures/Text/Photos: Pacific Automotive Network Question and Answer Calling the Beast)