Out of balance rotating system

1. May 6, 2013

Bravemeister

Figure Q4. illustrates a rotor assembly with out-of-balance rotor discs in planes A, B
and C. The out-of-balance mass x radius products in planes A and C are as
indicated in the figure. The out-of-balance mBrB in plane B and its angular position $\Theta$B
are such that the system is in static balance.

(a) Determine the values of mBrB and $\Theta$B.

(b) If the system is to be dynamically balanced by adding balancing masses m1r1
and m2r2 in planes A and C, respectively, determine their values and angular
positions $\Theta$1 and $\Theta$2.

Any help is much appreciated!

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Last edited: May 6, 2013
2. May 6, 2013

SteamKing

Staff Emeritus
What don't you understand about part a?

3. May 6, 2013

Bravemeister

well how to do it, in my lecture notes I says to take moments about a point, so I chose to go about point A. so from that I drew a moment polygon. I need to find sommething called a closing vectpr, I presume so thwt from point C I cwn return to point A therfore using some angles and other maths calculate a values for the question. I just dont know how to ge the closing vector.

4. May 6, 2013

Bravemeister

sorry for the horrid spelling my tablet keyboard is crap

5. May 6, 2013

SteamKing

Staff Emeritus