Common faults of speed sensor

There are many complicated reasons for the speed sensor. Due to the quality of the motor manufacturing, the motor with the number of poles greater than 8 will not vibrate. The limit value and test method of the speed sensor stipulates the vibration limit of the rigid foundation of the motor with different center heights on the rigid foundation. Measurement method and judgment standard. According to this standard, it can be judged whether the motor meets the standard.

The vibration of the motor will shorten the insulation of the winding and the service life of the bearing, and affect the normal lubrication of the sliding bearing. The vibration force will promote the expansion of the insulation gap, and the external dust and moisture will invade, resulting in a decrease in insulation resistance, an increase in leakage current, and even insulation shock. Wear. In addition, when the motor vibrates, the cooler water pipe is easy to crack and the solder joints are easy to open. At the same time, it will damage the load machinery, reduce the precision of the workpiece, cause fatigue of all vibration mechanical parts, loosen or break the anchor screws, and cause carbon brushes and slip rings Abnormal wear, severe brush fires or even burnt collector ring insulation, the motor can generate a lot of noise, which usually occurs in DC motors.

1. Rotor, coupling, coupling, transmission wheel (brake wheel) caused by imbalance.

2. The iron core bracket is loose, the oblique key pin is invalid, loose, and the rotor binding is loose, which will cause the unbalance of the rotating part.

3. The shafting of the connecting rod part is not centered, the center lines are not coincident, and the centering is not correct. This fault is mainly caused by poor alignment and improper installation during the installation process.

4. The center line of the connecting rod part coincides in the cold state, but after running for a period of time, due to the deformation of the rotor fulcrum and the foundation, the center line is damaged, resulting in vibration.

5. The gears and couplings connected to the motor are faulty, the gears mesh poorly, the teeth are severely worn, the couplings are poorly lubricated, the couplings are skewed, misaligned, the gear coupling tooth profile, the pitch is incorrect, and the clearance is too large Large or severely worn, it will cause certain vibration.

6. The structural defects of the motor itself, the elliptical journal, and the bending shaft, the gap between the shaft and the bearing Bush is too large or too small, the rigidity of the bearing seat, the foundation plate, the foundation part and even the entire motor installation foundation is not enough.

7. Installation problem: The motor and the bottom plate are not firmly fixed, the foot bolts are loose, and the bearing seat and the bottom plate are loose.

8. If the gap between the shaft and the bearing pad is too large or too small, it will not only cause vibration, but also cause abnormal lubrication and temperature of the bearing pad.

9. The load conduction vibration driven by the motor, such as the vibration of the motor-driven fan and water pump, causes the speed sensor.

10. AC motor stator wiring error, wire-wound asynchronous motor rotor winding short circuit, synchronous motor excitation winding turn-to-turn short circuit, synchronous motor excitation coil connection error, cage-type asynchronous motor rotor broken bar, rotor core deformation, resulting in stator-rotor air gap Unevenness, resulting in unbalanced air gap flux, resulting in vibration.