Cemb Hofmann UK

Cemb Hofmann UK
UK Specialist In Balancing Machine Sales & Contract Balancing

Tuesday, 14 May 2013

The Common & Frequent Words of Balancing

Balancing is a complex and tricky artform - producing a technical language that is riddled with certain phrases and words that would confuse many customers in need of balancing advice.

Below is an explanation of two of the most common used terms.

Static balancing :  Unbalance measuring and correction is carried out in one plane only.

Dynamic balancing :  Unbalance measuring and correction is carried out in two different planes.

Correction planes :  Is the section (plane) where unbalance correction is performed by adding or removing mass.

static and dynamic balancing

At Cemb Hofmann we pride ourselves in the delivery of first class balancing services - from high quality machine sales to a world-class sub contract balancing service.

To find out more visit www.cembhofmann.co.uk or call our team today on 0161 872 3123

Balancing Speed: A Comprehensive Explanation

The unbalance of a rotor is caused by the radial distribution of its masses along its axis of rotation.

The consequence is that if the rotor is rigid, and this means that the values and relative positions of its masses do not change, the unbalance does not change with the speed. In a rigid rotor the operating speed does not modify mass distribution and consequently has no influence on the unbalance.

By adding a 20 gr mass at a defined radial position on a perfectly balanced disc an unbalance is generated. This unbalance does not change with the speed, it is just necessary to remove the added 20 gr mass independently of rotor speed.

For rigid rotors the balancing speed does not need to be specified because it is related only to machine sensitivity and not to the rotor unbalance which is under measurement.

Modern hard bearing balancing machines have the capability to measure the dynamic unbalance starting from 70 RPM.

The unbalance effect (centrifugal force) increases with speed, the electric signal increases at the same time and so machine sensitivity tends to increase because of a better ratio signal to noise.
Depending on the model and manufacturer optimum sensitivity values are obtainable starting from 400 to 600 RPM.

Note: don’t get confused between the cause (unbalance) with its effect (centrifugal force or vibration).

The effect increases with the speed while the cause (unbalance) in a rigid body does not change.

For further information about any aspect of balancing please visit www.cembhofmann.co.uk or call our expert team today on 0161872 3123.