Noise is a very typical failure case of motors. It can be divided into mechanical, electrical and ventilation types based on the mechanism of its generation. In comparison, the sound caused by electricity is easy to identify, that is, it can be judged by cutting off the power supply; and the noise caused by ventilation can also be easily identified by blocking the air vents, but for mechanical noise, it is necessary to distinguish it through listening, feeling and other experience.
A netizen provided a fault case. During routine inspection, a maintenance worker found that a motor made an abnormal sound, which was very similar to the sound made by the bearing. However, preliminary inspection did not reveal any abnormality in the bearing system. Therefore, a professional with relatively rich experience was invited to analyze and determine. Further inspection found that the temperature of the motor housing was significantly higher than before, and obvious abnormalities could be found by touching it. The motor was then disassembled and inspected, and it was found that the stator and rotor parts of the motor had mechanical friction marks of varying degrees (as shown in the following picture). The factors that caused the noise were basically determined, that is, relatively hard foreign matter entered the air gap between the stator and rotor of the motor, causing damage to the stator or rotor when the motor rotated. Moreover, as the motor rotated, the foreign matter would move radially or axially, causing a large range of damage marks on the stator or rotor.
In the actual production and processing or motor maintenance process, the bearing system and the inner cavity of the motor should be kept clean and tidy. Foreign matter introduced in any process may cause interference mechanical noise in the motor. If it is a conductive foreign matter, it is very likely to cause the motor winding to heat up or even burn. Metal shavings generated in any link such as the lamination of the motor stator and rotor core, rotor turning, and the processing of the base or end cover, including metal foreign matter introduced during the motor maintenance process, may cause abnormal operation of the motor if they are not cleaned up properly. Clean production is a necessary condition to ensure the reliability of motor products.
Post time: Apr-04-2025