Cardan Shaft Alignment

As shown in the opening images on this page, a cardan shaft is, in the simplest terms, a spacer shaft with a universal joint coupling on each end. (Its name comes from a 16th-century Italian mathematician, Girolamo Cardano.) This type of arrangement allows power to be transferred between two machines that are offset from each other. Widely used in industry, cardan shafts have proven practical on applications where space is limited— as well as in situations where an element in the machine train (e.g. paper roll) may need to be actuated (dynamically positioned) to an alternate position when the machines are not running. The universal joint shaft allows for limited movement without uncoupling. To ensure sufficient lubrication circulation, which in turn prevents the universal joints from seizing, cardan shafts are normally installed with an angle from 4 to 6 degrees at the universal joints. Experience, though, has shown that the angle between the shafts of the driver and drive...