Motor balancing spec.

[RichLeimbach]

I have a rotating member in one of our products that is spinning at a relatively high rate of speed (18,000 RPM). I would like to get this component balanced to reduce vibration, etc. I am thinking of using the specs from a electric motor armature of similar size (maybe a 48mm motor) and similar speed as a starting point for this work, but I cannot find standard values for this data anywhere. Does anyone know the tolerances that this type of motor is usually balanced to or have any other ideas for setting this spec?

 

[EagleCove1]

Refer to the industry Standard Vibration Severity Chart that is referenced by IRD Mechanalysis, Inc. of Columbus, Ohio 43229

Maintaining Axial Vibration level at 1/2 of the Radial Vibrations is a standard application.

However at 18K CPM your axial vibrations should be in the VERY SMOOTH TO EXTREMELY SMOOTH ranges of this scale.


You should be good to go...

 

[jbartos]

Suggestion: Visit

http://www.spex.ca/Products/Masters...h-and-Elect-Engineering_Table-of-Contents.pdf

e.g. for Master Specification Section 15950

 

[jclough]

Sounds as though you idea could work. Check to make sure that the rotor masses are similat too. The vibration level of your rotor will also be largely dependent of the stiffness of the supporting structure while operating.

ISO 1940 is a good place to start.It seems as though a G2.5 balance level should be adequate. This works out to about .00006 oz-in/oz of rotor mass. Given a 16 oz rotor, this would work out to about .001 oz-in or .0005/plane for a two plane balance.

Remember that balancing will only take care of the 1X vibration due to unbalance. Vibration due to roundness errors or alignment issues may still be significant.

The above is just a place to start. A stiff mounting may be tolerant of more unbalance.

ther are balance tolerance calculators available at various place on the web. Try

http://www.corvib.com/vibration/balweight.cfm

If you need some help to set a spec, I'll be happy to work with you. No charge of course.