Glossary Balancing Technology

Sensitivity to unbalance (influence coefficient

Measure of how much the vibration of a rotor changes due to a change in unbalance. It is represented as ratio between the change of the vibration vector and the change of the unbalance vector.

Service speed

Speed at which a rotor revolves under operation.

Setting

Actions in order to enter rotor- and balancing-specific information into the measuring device of a balancing machine.

Shaft or rotor axis

The straight line joining the journal centers of a rotor.

Side-spindle balancer

Balancing machine configuration in which the rotor is mounted horizontally and overhung to a balancing spindle.

Single-plane (static) balancing

Procedure by which the mass distribution of a rigid rotor is adjusted in one plane to ensure that the residual static unbalance is within specified limits.

Single-plane (static) balancing machine

Balancing machine which utilizes the gravity or centrifugal forces in order to balance a rotor for one single plane.

Soft bearing (displacement-measurement) balancing machine

Machine used for balancing of rotors at speeds beyond the critical speed of the system rotor and balancing machine support.

Specific unbalance

Amount of the static unbalance divided by the rotor's mass in gmm/kg or µm.

Static unbalance

Unbalance that displaces the main principal axis parallel to the shaft axis. This may be caused by a single unbalance in the same plane as the center of gravity.

Susceptibility to unbalance

Probability for a machine to show a substantial change of unbalance within a certain time of operation.

Swing diameter

The biggest rotor diameter which can be used with a balancing machine.