Large horizontal vibration at the front end of the motor
Thread Content
The 800KW motor, operating at 10KV, has a rated current of 56A. It is equipped with a screw-type refrigeration unit; after maintenance, the load on the unit increased to over 80%, with a current of around 30A. There is significant horizontal vibration at the front end of the motor, amounting to 5.5 mm/s, while the temperature is 41°C. The vertical vibration at the front end is 2.6 mm/s. Both the horizontal and vertical vibrations at the rear end of the motor are within 2 mm/s. The vibrations at both the front and rear ends of the unit are within 4 mm/s ； The motor bearing uses hemispherical bushings ； Before and after the no-load test of the motor, the vibration levels at both the front and rear ends were within 1.5 mm/s. The alignment of the couplings was carried out using a laser aligner (it was done twice), with the alignment error being within 0.05 mm. After the motor started running under no-load conditions, it found its own magnetic center line. The motor has just been returned from the repair shop; I would appreciate your insights on why the horizontal vibration level is high
An 800KW motor – 5.5mm/s vibration is not considered high
The likelihood of loose bearing support, loose frame, and faults within the bearings themselves is high~~~~ Alignment issues, rotor bending problems, and static/dynamic friction problems can be ruled out~~~~~~~~~~~~~~ The available criteria are not sufficient for a definitive determination.
For other units of the same model, the vibration is within 3 mm/s
The front axle temperature was entered incorrectly; it’s 60℃
2984 r/min; the height of the axis centerline is h, with h being less than or equal to 225 mm, and the maximum vibration velocity is 4.5 mm/s； When h is greater than 225 mm, the maximum vibration velocity is 7.1 mm/s