Leaders in balancing technology
Friday, 01 May 2009 15:24
One of the most important rules in dynamic balancing is that for every one micron (0.001mm) of error you will see 1gmm (gram millimetre) of unbalance. This rule can be used when designing or selecting what type of tooling to use for your dynamic balancing application or it can be used to calculate what expected unbalance you will see if a part has location clearance or displaced from its rotational axis.
For example: When purchasing tooling for a dynamic balancing application you need to know the manufacturers stated repeatability of the tooling. You can then use this rule, so multiply this figure by the mass of the part you are balancing and you can see the potential amount of unbalance you will see. If the tooling repeatability is quoted at 2.5 microns (0.0025mm) and the part weighs 2kg you could potentially see 5gmm of unbalance repeatability.
If a part such as a pulley has a bore with clearance of 0.05mm (50 microns) to the shaft where it locates and the pulley weighs 10kg then you would see 500gmm of unbalance when the pulley is fully to one side such as if the shaft is in a horizontal axis.
It’s a simple rule and with appropriate application you can save making costly errors by selecting the correct tooling or correct design tolerances at the outset.
