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Difference between revisions of "Balancing single/dual plane"
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A rotor is a shaft rotating around its axis during service. In general such a rotor consists of a shaft with one or more discs fitted to the axle. Such discs can be fly wheels, grinding wheels, turbine wheels, etc. The shaft is usually running in bearings allowing the rotation of the body. Depending on their rotational speed, two basic categories can be defined to classify rotors: <u>rotors with rigid shaft</u>, and <u>rotors with flexible shaft</u>. <br> | A rotor is a shaft rotating around its axis during service. In general such a rotor consists of a shaft with one or more discs fitted to the axle. Such discs can be fly wheels, grinding wheels, turbine wheels, etc. The shaft is usually running in bearings allowing the rotation of the body. Depending on their rotational speed, two basic categories can be defined to classify rotors: <u>rotors with rigid shaft</u>, and <u>rotors with flexible shaft</u>. <br> | ||
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If the operating speed remains below half of the first critical bending speed, the shaft does not deflect : it may be considered as a rotor with a rigid shaft. At such operational speeds and due to the non circular cross section of the rotor, the axis of rotation (Z) and the inertial axis ( | If the operating speed remains below half of the first critical bending speed, the shaft does not deflect : it may be considered as a rotor with a rigid shaft. At such operational speeds and due to the non circular cross section of the rotor, the axis of rotation (Z) and the inertial axis (&Dela) does not coincide (e.g. the mass is not evenly dispatched in a section of the shaft). This may results in a tumbling movement of the structure, which amplitude depends on the bearing clearance and stiffness. In any case, the bearings are subjected to unnecessary or even non allowed loads. | ||
[[Image:Unbalanced_shaft_schem.png|framed|none]]<br> | [[Image:Unbalanced_shaft_schem.png|framed|none]]<br> | ||