How to find the cause of vibration
In order to eliminate the vibration of the motor, we must first find out the cause of the vibration. Only by finding the cause of the vibration can we take targeted measures to eliminate the vibration of the motor.
1. Before the motor is not stopped, check the vibration of each part with the vibration meter. For the vibration part, test the vibration value in three directions of vertical horizontal axis. If the ground screw is loose or the bearing end cover screw is loose, Directly tighten, measure the vibration size after tightening, observe whether there is elimination or lightening, secondly check whether the three-phase voltage of the power supply is balanced, whether the three-phase fuse is blown, and the single-phase operation of the motor can not only cause vibration, It will also cause the temperature of the motor to rise rapidly, observe whether the current meter pointer swings back and forth, and the current swing phenomenon occurs when the rotor breaks. Finally, check whether the three-phase current of the motor is balanced. If problems are found, contact the operating personnel to stop the motor running in time to avoid burning the motor. damage.
2. If the motor vibration is not solved after the surface phenomenon is processed, continue to disconnect the power supply, uncoupling the coupling, and separate the load connected to the motor. Single-turn motor, if the motor itself does not vibrate, the vibration source If the coupling is not looking for a positive or load machine, if the motor vibrates, it means that the motor itself has a problem. In addition, the power-off method can be used to distinguish whether it is an electrical cause or a mechanical cause. When the power is cut off, the motor will not vibrate immediately. If the vibration is relieved, it means that it is an electrical cause, otherwise it is a mechanical failure.
Overhaul for the cause of the failure
1. Overhaul of electrical causes:
The first is to determine whether the three-phase DC resistance of the stator is balanced. If it is unbalanced, it means that the welding part of the stator is welded, the winding is separated by phase, and the winding is short-circuited. If the fault is obvious, it can be insulated. The surface is burnt, or the stator winding is measured with an instrument. After confirming the inter-turn short circuit, the motor winding is re-routed.
For example: pump motor, the motor is not only vibrating, but the temperature of the bearing is also high. The test results show that the DC resistance of the motor is unqualified, and the stator winding of the motor has a phenomenon of open welding. After the fault is found by the elimination method, the motor runs normally.
2. Maintenance of mechanical reasons:
Check that the air gap is uniform. If the measured value is exceeded, re-adjust the air gap. Check the bearing, measure the bearing clearance, if it is not qualified to replace the new bearing, check the deformation and looseness of the core, loose the core can be bonded with epoxy resin, check the shaft, repair the reaming of the curved shaft or directly straight shaft Then do a balance test on the rotor. During the trial operation of the blower motor overhaul, the motor not only has a large vibration, but also the temperature of the bearing bush exceeds the standard. After several days of continuous processing, the fault remains unresolved. When the team members helped to find out, the air gap of the motor was very large, and the level of the tile seat was not qualified. After the fault was found, the motor was successfully tested once after re-adjusting the gaps.
3. The load mechanical part is checked normally:
There is no problem with the motor itself. The cause of the fault is caused by the connection part. At this time, check the basic level of the motor, the inclination, the strength, whether the center is correct, whether the coupling is damaged, and whether the motor shaft extension meets the requirements. and many more
