The cause of motor vibration analysis

1 the dangers of motor vibration

Motor vibration will accelerate motor bearing wear, bearing the normal service life greatly shrink short, at the same time, the motor vibration will bring down the winding insulation. Due to vibration motor end cable tie loose move, mutual friction caused the end windings, insulation resistance is reduced, the insulation life expectancy, serious when insulation breakdown. In addition, the drag mechanical motor vibration can cause damage to the normal operation of the equipment four weeks, made a lot of noise.

2 the cause of motor vibration

The cause of three-phase asynchronous motor vibration is mechanical and electromagnetic two reasons.

Mainly exist in mechanical anchor fastening rickety, basic mesa tilt, uneven; Bearing damage, shaft bending deformation, the motor axis center its drag mechanical axis inconsistency; , rotor magnetic flux, the rotor dynamic balance etc.

Mainly exist in electromagnetic three-phase voltage imbalance, single-phase motor running. Unbalanced three phase current, the phase resistance reactance unbalance, asymmetry of motor running. Motor windings to line error after rewind, turn the mouse cage is broken, short circuit ring crack, etc.

3 check and eliminate the vibration of the motor

Motor vibration is usually large, should be used in vibration table ministries measuring points along the horizontal and vertical direction vibration value, and make the corresponding record. Sound and listen to the motor stator cavity internal bearing rotating sound, check the anchor, such as no obvious anomalies, takes off the drag machinery, (home of electrician http://www.pw0.cn) separate idling electric machine, is to determine the vibration motor itself or drag caused by mechanical vibration. After will send now the motor repair in production for a variety of reasons cause asymmetric three-phase winding magnetic potential, when in light load or low load motor's vibration is not very obvious, but once meet with load increase, electric machine vibration will gradually increase.

In production we often power method is used to distinguish between vibration is caused by electromagnetic or mechanical reasons. Power law namely on running under the rated speed of the motor power is suddenly, if the vibration is reduced, suddenly can judge is caused by electromagnetic reasons, if the vibration value is not very big change, may be caused by mechanical reasons.

For vibration caused by the mechanical aspects, if because of the bearing wear, should be replaced immediately with the type Bearing; If due to the axis of bending deformation, it must be for the school shaft or replacement shaft; If not firm to Angle for fastening, the tight tightly again. Foundation strength is insufficient, bedplate rugged seemingly small, but is often the most direct cause of the vibration. I plant a high voltage motor vibration is larger, to center is for many times, but failed to eliminate vibration, after the drive motor, found the foundation bedplate composed of two pieces of steel plate joining together, on one side of the steel plate is a bit high, on the other side is low, have not smoothed thebutt welds, and occurred in motor side under the foot, although motor by the alignment, but in fact there are many places to form a little bit of contact area, motor and mechanical center has been looking for is just an illusion, a run will inevitably produce electric machine vibration. Take gas cutting open to joining together, welding and grinding smooth, motor again after alignment, try turning vibration increase instead, after analysis and find the reason, only to find that steel plate after cutting, and after welding, thermal damage, as a strength has been tough After weight, motor rotation and steel plate form resonance, so instead of vibration increase, to do after based mesa, to eliminate. Another poor rotor dynamic balance is the root cause of the vibration, motor in the factory, the rotor has been dynamic balance calibration qualified, but in the process of repair motor (especially in high voltage motor repair), often do not pay attention to the scale mark this link, one of dismantling the dynamic balance check whole parts, remounted after, will cause poor dynamic balance, the motor vibration, eliminate the method to check only the dynamic balance.

For vibration caused by the electromagnetic aspect, from the power of began to check. Check whether three-phase voltage balance, clip-on ammeter measure three phase current balance, is there a single phase operation, found in the production of motor terminal box end connection because of tight and firm, often burn out, caused by single phase operation, should strengthen the inspection and to eliminate. If, when measured with a clip-on ammeter, found three phase current imbalance, whose hands when swing high and low, that the rotor cage bar fracture phenomenon. At this time Should immediately stop the motor running, cut off power supply, the rotor can be taken out for examination and repair. In addition, should also measure three phase stator winding resistance value, check whether the winding is symmetrical, if the resistance unbalance, then open welding parts, also should take out the rotor for inspection, after welding. The cause of motor vibration analysis

1 the dangers of motor vibration

Motor vibration will accelerate motor bearing wear, bearing the normal service life greatly shrink short, at the same time, the motor vibration will bring down the winding insulation. Due to vibration motor end cable tie loose move, mutual friction caused the end windings, insulation resistance is reduced, the insulation life expectancy, serious when insulation breakdown. In addition, the drag mechanical motor vibration can cause damage to the normal operation of the equipment four weeks, made a lot of noise.

2 the cause of motor vibration

The cause of three-phase asynchronous motor vibration is mechanical and electromagnetic two reasons.

Mainly exist in mechanical anchor fastening rickety, basic mesa tilt, uneven; Bearing damage, shaft bending deformation, the motor axis center its drag mechanical axis inconsistency; , rotor magnetic flux, the rotor dynamic balance etc.

Mainly exist in electromagnetic three-phase voltage imbalance, single-phase motor running. Unbalanced three phase current, the phase resistance reactance unbalance, asymmetry of motor running. Motor windings to line error after rewind, turn the mouse cage is broken, short circuit ring crack, etc.

3 check and eliminate the vibration of the motor

Motor vibration is usually large, should be used in vibration table ministries measuring points along the horizontal and vertical direction vibration value, and make the corresponding record. Sound and listen to the motor stator cavity internal bearing rotating sound, check the anchor, such as no obvious anomalies, takes off the drag machinery, (home of electrician http://www.pw0.cn) separate idling electric machine, is to determine the vibration motor itself or drag caused by mechanical vibration. After will send now the motor repair in production for a variety of reasons cause asymmetric three-phase winding magnetic potential, when in light load or low load motor's vibration is not very obvious, but once meet with load increase, electric machine vibration will gradually increase.

In production we often power method is used to distinguish between vibration is caused by electromagnetic or mechanical reasons. Power law namely on running under the rated speed of the motor power is suddenly, if the vibration is reduced, suddenly can judge is caused by electromagnetic reasons, if the vibration value is not very big change, may be caused by mechanical reasons.

For vibration caused by the mechanical aspects, if because of the bearing wear, should be replaced immediately with the type Bearing; If due to the axis of bending deformation, it must be for the school shaft or replacement shaft; If not firm to Angle for fastening, the tight tightly again. Foundation strength is insufficient, bedplate rugged seemingly small, but is often the most direct cause of the vibration. I plant a high voltage motor vibration is larger, to center is for many times, but failed to eliminate vibration, after the drive motor, found the foundation bedplate composed of two pieces of steel plate joining together, on one side of the steel plate is a bit high, on the other side is low, have not smoothed thebutt welds, and occurred in motor side under the foot, although motor by the alignment, but in fact there are many places to form a little bit of contact area, motor and mechanical center has been looking for is just an illusion, a run will inevitably produce electric machine vibration. Take gas cutting open to joining together, welding and grinding smooth, motor again after alignment, try turning vibration increase instead, after analysis and find the reason, only to find that steel plate after cutting, and after welding, thermal damage, as a strength has been tough After weight, motor rotation and steel plate form resonance, so instead of vibration increase, to do after based mesa, to eliminate. Another poor rotor dynamic balance is the root cause of the vibration, motor in the factory, the rotor has been dynamic balance calibration qualified, but in the process of repair motor (especially in high voltage motor repair), often do not pay attention to the scale mark this link, one of dismantling the dynamic balance check whole parts, remounted after, will cause poor dynamic balance, the motor vibration, eliminate the method to check only the dynamic balance.

For vibration caused by the electromagnetic aspect, from the power of began to check. Check whether three-phase voltage balance, clip-on ammeter measure three phase current balance, is there a single phase operation, found in the production of motor terminal box end connection because of tight and firm, often burn out, caused by single phase operation, should strengthen the inspection and to eliminate. If, when measured with a clip-on ammeter, found three phase current imbalance, whose hands when swing high and low, that the rotor cage bar fracture phenomenon. At this time Should immediately stop the motor running, cut off power supply, the rotor can be taken out for examination and repair. In addition, should also measure three phase stator winding resistance value, check whether the winding is symmetrical, if the resistance unbalance, then open welding parts, also should take out the rotor for inspection, after welding.