Overview and Selection Guide of Shaft Couplings

A coupling, also known as a shaft coupling, is a mechanical component used to firmly connect the driving shaft and the driven shaft of different mechanisms so that they rotate together and transmit motion and torque. Sometimes, it is also used to connect a shaft to other parts, such as gears or pulleys.
A coupling usually consists of two halves, each connected to the respective shaft end by a key, interference fit, or other method, and then joined together in a specific way.
Couplings can also compensate for the misalignment between two shafts caused by manufacturing and installation inaccuracies, deformation during operation, or thermal expansion — including axial, radial, angular, or combined misalignment — and can also help absorb shock and vibration.

When selecting a coupling type, the following factors should be considered:

1.The magnitude and nature of the torque to be transmitted, the requirements for buffering and vibration damping, and the possibility of resonance.

2.The degree of relative displacement between the two shaft axes caused by manufacturing and assembly errors, load deformation, thermal expansion, or relative motion of components.

3.The allowable dimensions and installation method, as well as the operating space required for assembly, adjustment, and maintenance. For large couplings, disassembly and assembly should be possible without axial movement of the shafts.

In addition, environmental conditions, service life, lubrication, sealing, and economic factors should also be considered. Based on these and the characteristics of different coupling types, a suitable coupling should be selected.