Schenck Rotec Corporation

Schenek Rotec Gmbh

Matthias Hartnagel

Thomas Wanke

Matthias Breitwieser

Stephan Frese

Kai Dr Trukenmüller

In a method for determining an equivalent modal unbalance for the first bending characteristic form of a shaft-elastic rotor, which unbalance is to be compensated for, a rotor model is created describing the geometric shape and material properties of the shaft-elastic rotor. The magnitude of compliance of the rotor model is calculated at a measurement point and at the center of gravity of the rotor at an assumed speed. The shaft-elastic rotor is received in a rotatable bearing and accelerated to the assumed speed which is below its first critical speed. Subsequently, the magnitude of outward deflection at the measurement point of the shaft-elastic rotor rotating at the assumed speed can be measured. The equivalent modal unbalance for the first bending characteristic form of the shaft-elastic rotor, which unbalance is to be compensated for, can be calculated from the magnitudes of the calculated compliance and the measured outward deflection.

Method for determining an unbalance of a shaft-elastic rotor with reference to the outward deflection

Disclosed is a method for determining the static unbalance of a body () provided with a locating surface () by means of a center-of-gravity weighing scale (), the method including measuring the position of the locating surface () of the body () with respect to its mount by means of electric displacement sensors (), computing from the measurement signals of the displacement sensors () the eccentricity of the locating surface () of the body () with respect to the reference point of the scale () by means of an electric evaluating circuit, weighing the body () and recording mass and position of the center of gravity of the body () with respect to the reference point of the scale (), and computing the unbalance of the body () from the measurement signals of the scale () and the eccentricity of the locating surface () of the body () with respect to the reference point of the scale () by means of the evaluating circuit.

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Bensheim, Germany

Matthias Hartnagel