Couplings can also serve a compensating function to accommodate, as shown in the diagrams, axial and radial shaft misalignment (also known as longitudinal and transverse misalignment), as well as angular misalignment. These misalignments can have various causes: Longitudinal displacements can result from thermal expansion or armature displacement (in electric machines), whereas transverse and angular displacements are caused by installation inaccuracies, warping of machine frames, foundation settlement, or elastic mounting. Angular errors can also result from torque spikes and torsional vibrations. These torque spikes can be mitigated or dampened by a coupling. [2]

The first image shows a multi-disc clutch. Its cage contains several inner and outer discs, which allow high torques to be transmitted despite the small diameter. The coil springs visible in the cutaway model generate the contact force between the discs. [3]

Disc couplings consist of several friction discs connected in series and alternately linked to the coupling halves, which increases the number of friction surfaces. This, in turn, increases the transmissible torque proportionally. [1]

This demonstrator shows an elastic claw coupling. It is a non-switchable coupling and consists of two coupling halves with so-called concave claws. In the spaces between them, these claws engage with a star-shaped insert made of Vulkolan, whose teeth are spherical in shape. This serves to reduce or prevent edge pressure during shaft misalignment. The elasticity helps prevent start-up shocks and compensates for axial misalignment.

Examples of applications include: fans, centrifugal pumps, hoists. [7]

Try it out: Pull the two coupling halves apart and bend the elastic star slightly.

The demonstrator shown here illustrates how a magnetic coupling works. The two coupling discs have recesses in which magnets are mounted. Since this is a demonstration model, only a few magnets are installed. This allows the discs to be separated by pulling the shafts apart (just give it a try!).

Magnetic couplings offer the advantage that force can be transmitted through a wall, for example. This is used, for instance, in special pumps for the chemical industry that require a particularly tight seal. In such cases, there is no need to route a shaft through the housing. [6]