Motor Magnetic Center
Motor Magnetic Center
(OP)
I have been thrown a concept on Motor magnetic center.
After a recent failure it was argued that over tightening a coupling restricted axial movement that is normally expected on larger induction motors once they have been energized or return to rest!
Personally, I have never heard of this theory nor have I seen or can find any motor spec containing such information
How real is this?
After a recent failure it was argued that over tightening a coupling restricted axial movement that is normally expected on larger induction motors once they have been energized or return to rest!
Personally, I have never heard of this theory nor have I seen or can find any motor spec containing such information
How real is this?





RE: Motor Magnetic Center
Operating experience on horizontal sleeve bearing induction machines has shown that sufficient thrust to damage bearings may be transmitted to the induction machine through a flexible coupling. Damage will be avoided if the following limits are observed by the machine manufacturer and the assembler of the motor to driven equipment:
Motor Speed min. Rotor Max coupling
HP rpm end float end float
500> 1800 > 0.25” 0.09”
300-500 3000-3600 0.50" 0.19”
600 < All 0.50" 0.19"
RE: Motor Magnetic Center
Ideally magnetic center and mechanical center are not too far apart and you can set on either one. Most important requirement is to set so the motor won't run on a thrust shoulder. 2nd most important is to allow it to run on magnetic center.
There is a very lot that can be said on this subject. Can you give more details of your situation. Is it sleeve bearing machine? What type of coupling? Details of failure.
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RE: Motor Magnetic Center
Locate the shaft mark for the magnetic center against the reference in the pedestal and align the coupling. The max allowed displacement coupled should be into the limits and never should touch the bearing shoulders while reaching the natural magnetic axial center
RE: Motor Magnetic Center
RE: Motor Magnetic Center
For measuring the physical center it is easier to push & pull the shaft when the motor is running instead of stopping.
Simple pencil can push the shaft as the shaft is floating on the oil film. Rotating the shaft in stationary condition may score the bearing surface.
RE: Motor Magnetic Center