Why vertical squirrel cage induction motor prone to noise?
YE3 series squirrel cage induction motor, 315kw, 4 pole, 1485rpm, 380v, 50hz, IP55, Vertical mount, Due to vibration and noise is too large, not allowed to leave the factory. After discussing with the engineer of the company, it is decided to make some fine adjustments in the axial direction of the squirrel cage induction motor. Re-test the original fault completely eliminated. In response to this problem, we draw on the characteristics of the vertical squirrel cage induction motor installation to discuss, share experiences and exchange and sharing with you.
Vertical squirrel cage induction motor structure of the particularity
Compared with the horizontal motor, vertical motor, especially the high-power vertical 3 Phase Induction Motor bearing system has its particularity, the motor will be used at one end of the angular contact ball bearings. Due to the particularity of the structure of angular contact ball bearings, must not be installed in the wrong direction of assembly of the bearing assembly, bearing damage or direct. When the bearing is not in place or the motor itself, the bearing itself is mismatched with the axial alignment, etc., it is possible to cause three-phase induction motor to produce abnormal vibration and emit weird noises.
Angular contact ball bearings features
Single row angular contact ball bearings are designed for combined loads and provide high thrust in one direction. Most vertical squirrel cage induction motors employ a set of single row angular contact ball bearings on the non-axial ends for axial forces high enough to exceed the axial forces that a deep groove ball bearing can withstand. In size, with the corresponding squirrel-cage induction motor single row deep groove bearing interchange, to avoid the redesign of the structure and bring a series of unpredictable problems.
Angular contact ball bearings are also often used in gear reducer, pump, worm gear, vertical axis and machine spindle and other axial force larger occasions, when they are often installed in a variety of pairs of combinations.
Vertical squirrel cage induction motor angular contact ball bearing load mode
Vertical squirrel cage induction motor angular contact ball bearings, the purpose is to apply a balance with the rotor weight of the axial force to ensure that the rotor and stator axial relative position at equilibrium. Angular contact ball bearings are located below the motor rotor, lift way; located above the rotor when the motor is suspended.
Why easy to bearing the wrong place
Whether the lift or suspension installation, three-phase induction motor running, in addition to the matching axial size itself, after the motor is energized, the stator and rotor magnetic center line under the action of electromagnetic force spontaneously aligned, may lead to Rotor axial displacement, due to unavoidable Zhu parts accumulated processing errors and machine assembly deviation, the actual displacement will cause different degrees of axial displacement of the bearing itself. Bearing a serious dislocation, the spontaneous alignment of the electromagnetic force and the rotor gravity as the shift of the exciting force, exacerbated the bearing noise and vibration.
In the motor design, should be carefully analyzed bearing force situation, taking full account of the possible axial excitation force problem in the choice of three-phase induction motor bearing structure to do more work, such as the angular contact ball bearings paired use, bearing axial The direction of the stop and control, the motor uses three bearing structure, the motor stator just right pre-alignment and so on the specific measures. Among them, the motor stator pre-wrong size must be moderate, otherwise the result is counterproductive.
In particular, Electric Motor Manufacturers are prompted: vertical squirrel cage induction motor storage, transportation and testing process to ensure that the motor at the correct vertical state, to avoid the resulting harmful external damage caused by bearings.