ABSTRACT
The flexible coupling system consists of (1) two half couplings, (2) an intermediate member to provide flexibility, and for some specific types, a cylindrical cover. The flexible member can be of various designs, such as spline and sprockets, laminated disks, studs and rubber bushings, two sprockets held together by one concentric double-strand chain, and so on. Some types of flexible couplings will permit significant independent axial movement of each of the two shaft extensions, whereas other types will not. Those couplings that permit independent shaft movement are said to permit "end float." End-float couplings allow the motor shaft to correspond to "magnetic center" without being affected by the status of the shaft of the driven equipment. Such couplings also allow the rotating parts of the driven equipment, such as pump impellers, to expand axially when heated without preloading the motor bearings in an axial direction. Also, in some types of end-float couplings, the amount of possible end float can be controlled by placing axial pins within the coupling.
