Dynamic Balancing

 

Dynamic balancing a rotor means to reduce its dynamic unbalance to zero or to an acceptable level.

This process will eliminate costly and sometimes irrepairable damage to the unit and is absolutely essential to the maintenance and quality of rotating parts.

 

The dynamic unbalance is by definition:

 

 

So it is necessary to operate on two different planes.

 

Since the dynamic unbalance equivalent ot the total unbalance Ut can be calculated with reference to two arbitrary planes, the consequence is that thte two balancing planes (where material can be added or removed) can be chosen.

 

The above is valid for rigid rotors where mass distribution (local unbalances) does not vary with the speed.
 

 

In order to balance with the minimum effort two rules are valid:

 

 

1)  Choose balancing planes as far apart as possible

 

2)  Choose a balancing radius as large as possible

 

 

Note: by the dynamic balancing on two different planes the total unbalance (set of local unbalances) is not reduced to zero; only the dynamic unbalance (on two planes ) equivalent to the total unbalance Ut is reduced to zero.

 

 

 Discover more about dynamic balancing by visiting the Cemb Hofmann resource centre or call our expert balancing team on 0161 872 3123.

 

Couple Unbalance

A Definition of Couple Unbalance

The total unbalance is called couple unbalance if the equivalent unbalance is made by two vectors placed on two different planes having equal values and opposite directions.

 (The axis of inertia cuts the axis of rotation passing through the centre of mass)

 

 

Of course values Us and Ud (unbalance value in the two sections) are equal.

 

For example: if the declared couple unbalance value is 6000 gr.cm.cm and the distance between the two balancing planes is  15 cm, then the unbalance per plane is  6000/15 =400gr.cm (4000 g.mm ). If the balancing radius on each plane is 20 cm, then the unbalance per plane is 400/20=20grams (the two unbalances on each plane are equal in value but opposite in the angle position)

 

For more information on balancing or sub contract dynamic balancing services, please call our expert today on 0161 872 3123 or visit the Cemb Hofmann UK site.



Static Balancing

A definition of static unbalance

The total unbalance is called static if it is equivalent to a single unbalance vector placed in a section which also contains the centre of mass of the rotor.

(The axis of inertia is parallel to the axis of rotation)

 

If the equivalent vector is not located in one section containing also the centre of mass we call it quasi-static unbalance.

In practice most people call static unbalance the total equivalent unbalance when it is placed in a single plane only.

Cemb Hofmann specialise in static balancing machines and our expert team will be delighted to guide you through our balancing processes - from professional balancing machines to sub contract balancing services.

Call us now on 0161 872 3123 or visit the Cemb Hofmann UK site today.