Difference between static and dynamic balancing of rotating masses

hi all

so what is the difference between static and dynamic balancing of rotating masses. And how what is the need for dynamic balancing? Posted in: #Coffee Room

Hi zaveri
Static balancing is performed with the object being balanced at rest. Dynamic balancing is performed with the object being balanced in motion.
Static balancing is done without the part moving, dynamic is done with the part moving it is spun and using stroboscopic flash the heavy bit is higlighted and you then add or remove weighs till it stops vibrating.

In static balancing, the rod around which mass is rotating is to be fixed whereas in dynamic balancing,the rod moves along with the rotating mass.

so then how are the blades of a ceiling fan or any fan , balanced dynamically ? what is the procedure ?

I think that static balancing is the balancing of a material which, is at rest, with respect to some frame of reference. Mean to say that in static balancing we prevent the material from motioning either in rotational and translational with respect to some frame of reference while in dynamic balancing if an object is moving with constant velocity with respect to some particular frame of reference then we strict the object to keep its constant velocity state

static balance will be produced if the sum of the weights about the axis of rotation is zero...and a system is said to be in dynamic balanced when there doesnot exist any resultant centrifugal force as well as resultant couple.

Balancing of a rotating body is done to counter the extra forces in the direction other than the axis of rotation. This helps in avoiding the Vibrations in a body.

Static balancing is done where the center of gravity is on the axis of rotation of the body. Thus the body has no tendency to rotate under the influence of gravity.

Dynamic balancing is generally referred to a case where the body is either rotating about the axis due to an external force or by the change in the center of gravity of the body. The unbalanced forces thus generated create the Vibrations. Although many advanced techniques are available in the market, the most reliable, dependable and easy approach is to hit and trial the counter mass needed to create an extra force which would balance the unbalanced force.

This helps in the longer life of bearings and stops erosion of the shafts too.

A rotating object must have static balance before it can have dynamic balance. But the object can have dynamic imbalance even when it is statically balanced. If that is the case, the object will tend to vibrate while rotating even though it has no tendency to roll while stationary. dynamic balance can be thought of as the ability of an object to balance while in motion.