Axial force on induction rotor
Axial force on induction rotor
(OP)
On an AC induction motor, if the rotor and stator aren't aligned (that is, the rotor is shifted axially with respect to the stator), when the motor is turned on, will there be an axial force on the rotor? In other words, will the stator and rotor try to align themselves once power is applied?





RE: Axial force on induction rotor
"Will work for (the memory of) salami"
RE: Axial force on induction rotor
Can you explain your comment a little more? What does the size of the air gap have to do with the relative axial positions of the stator and rotor? Were you thinking I was asking about radial alignment?
RE: Axial force on induction rotor
Some more discusion
thread237-264609: Induction motor axial misalignment forces
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(2B)+(2B)' ?
RE: Axial force on induction rotor
Bill
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"Why not the best?"
Jimmy Carter
RE: Axial force on induction rotor
In the case of the babbitt bearing, there is usually up to 1/2" of endplay allowed and, if during alignment, the shaft is not located on magnetic center then damage will result. If the shaft is pulled to the inner or outer extreme of the endplay, the shaft journal will ride against the inner or outer thrust face and, because there is no 'mechanism' for delivering oil to the thrust face, bearing failure will result.
In the case of the roller bearing, it is more difficult to 'accomplish' this type of misalignment because there is very little endplay in the bearing. However, if you are 'forceful' in the alignment you can end up with axial thrust load on the bearing. In this case, the ends of the rollers will ride against both the inner and outer bearing races on alternate sides and this will result in quick bearing failure.
Ball bearings are more forgiving. I imagine that in the extreme case that it would be possible to cause a bearing failure due to axial misalignment but this, being the extreme case, is not common.