Introduction to Balancing:
In the previous block you studied forced vibration. In the system along rotating masses, the rotating masses contain eccentricity. A mass associated to a rotating shaft shall rotate along the shaft and In case the centre of gravity of the rotating mass does not lie on the axis of the shaft then the mass shall be effectively rotating around an axis at certain radius. As the mass need to remain at that radius, the shaft shall be pulled in the direction of the mass by a force equivalent to the centrifugal force because of inertia of the rotating mass. The rotating centrifugal force gives harmonic excitation to system that so causes forced vibration of the machines. Then we shall discuss how such a force may be balanced to eliminate the effect of unbalance. Generally the unbalance is expressed as product of mass and eccentricity.
Objectives
After learning this unit, you must be able to understand
- what is unbalanced force, and the influence of this,
- how is unbalanced force because of single rotating mass balanced, and
- how is unbalance force because of several rotating masses in the similar plane determined?