Key Phasor?

A key phasor does not work to remove bow of a shaft. A Keyphasor is simply a eddy current transducer that reads a notch on the shaft in order to give a once per rev voltage pulse.

Used in conjunction with eddy current transducers at the bearings, one can measure the phase angle of the bearing signals relative to the keyphasor. As the shaft makes its closesest approach to the bearing sensors, this part of the shaft corrolates with the direction of the bow in the shaft. This can then be physically marked by the phase angle relative to the keyphasor, since the notch is a known location. This is also how balancing is done.

A keyphasor is not necessary to identify a bowed rotor, but it is helpful in determining the direction of the bow.

I refer you to the Bently Nevada Orbit Magazine web site which has lots of articles on this sort of thing....

http://www.ge-energy.com/prod_serv/products/oc/en/orbitmagazine.htm

I agree with Steve S(He has some real good credentials) the key phasor is a reference point that is used in conjunction with vibration probes to determine where the "bow" or "high spots" are located on the shaft.Normally there will be two vibration probes looking at the shaft.If the shaft is vibrating you can figured out which of the vibration probes is "seeing" the vibration at the time the notch is in front of the key phasor or close to it then you can be determine where the "high spot or bow" may be in relation to the notch on the rotor. I hope this helps and is not too confusing...

the nuts and bolts man

Thank You very much, The links you gave are really very usefull and informative. I've not read it completely, though. I'll ask If I can't understand any thing.

Thanks again!

difficult 2 understand

hey,,this article will help you to understand more about keyphasor