ABSTRACT
Rigid couplings are used to connect machine shafts, where it is desired to maintain shafts in precise alignment, transmit torque and also transmitting axial thrust. Rigid couplings are found in certain vertical in-line pumps and at several locations on vertical turbine pumps where individual shaft sections must be joined together. Material-flexible couplings rely on flexing of the coupling element to compensate for shaft misalignment. Mechanically flexible couplings compensate for misalignment between two connected shafts by means of clearances incorporated in the design of the coupling. The coupling illustrated here was specifically designed to maximize its misalignment capability, as well as ensuring that it could be fitted in the space envelope of an existing gear coupling. Suffice it to say that while no one type of coupling is without its advantages and disadvantages, reliability-focused users will overwhelmingly agree that properly selected and installed disc pack couplings are the top choice for centrifugal pumps.
