clearance between shaft and shaft hub

[eduvillela]

hello all!

Can a high clearance between the shaft and the shaft hub lead to high vibration levels? And does it appear in the espectrum as 1x only ?

thank you in advance!

 

[Strong]

Yes and harmonics of 1xSS are likely, especially 4xSS.
Walt

 

[Tmoose]

The clearance by itself may not be an issue if the device is light-duty stocking-stuffer grade, and the set screws are well tightened.

But The change in centering of a formerly well "balanced" part CAN and WILL result in some greater amount of unbalance.

Note that eccentricity or change in centering of a mere 0.0015" uses up the entire G6.3 tolerance at 1800 rpm.
page 4 here -

http://www.irdbalancing.com/downloads/techpaper1balqualityreqmts.pdf

Shaft runout, resulting from shaft > ball/roller bearing fits or actual shaft runout also eagerly conspire to move even a snug fitting rotor off the rotating axis of the balance arbor, often making the "Precision electronic balanced" sticker pretty misleading.