Shaft couplings

A shaft coupling transfers torque between two in-line, or nearly in-line, rotating shafts. The magnitude of the torque in the shafts is equal, although slipping and disengagement can cause speed variations. In its simplest, and perhaps oldest form, the coupling acts as a means of joining shafts. Another function is to join two shafts which are not necessarily in perfect alignment with each other. The coupling in this case must be capable of absorbing such misalignment. Modern couplings,
between pump and driver, must be capable of rapid disassembly.