An aspect of the rotor dynamics, refers to determine the location and size of the generated when the rotor rotation unbalance amount (centrifugal force and couple, see relative motion) and the elimination of the operation. The transverse vibration of the unbalance caused by the rotor, and the rotor dynamic load is not necessary, which is not conducive to the normal operation of the rotor. So, most of the rotor dynamic balance should be. In the machine manufacturing or maintenance, a dynamic balance process.
The unbalance of the rotor rotation is generated when the centroid for each micro rotor is not strictly in the rotary axis of the cause. The centrifugal force of each micro segment due to mass deviation arising from the rotation axis perpendicular to the axis of rotation. The force can be synthesized by centrifugal force system for the synthesis of a concentrated force, its direction is perpendicular to the axis. In general, at least two concentrated force acting on the two can be used respectively on the cross section of the original department on behalf of the centrifugal force. If the two concentrated force just to form a couple, the original unbalance in the rotor is rolling is unable to detect and measure the; rotation, a couple to form transverse interference and causes the rotor vibration. The effect of this imbalance can detect and measurement only in the rotation of the dynamic, so it is necessary to carry out dynamic balance. Static balance contrast refers to the quality when the rotor is concentrated thin disk that can be viewed as a perpendicular to the axis of rotation regardless of thickness, without rotation can balance. The practice is to be placed on one side of the rotor level, under the action of gravity will be down to the bottom, try to adjust the rotor centroid position, which is located in the axis of rotation.
In measured unbalance the location and size of, or is directly to get rid of it, or is in the direction it is symmetric and its corresponding quality to balance its effect is heavy in the past or a counterweight to finish the balancing.
According to the rotor deformation and mass distribution, dynamic balance dynamic balance is divided into rigid rotor and flexible rotor dynamic balancing.