Metallic Membrane Couplings

Disc Clutches 

Disc clutches have a thin plate of laminated discs as the main part of the clutch to flexibly accommodate misalignment. They consist of two cubes on each side and a spacer as the central element, which are connected by discs on both sides. The functional principle of the disk clutch means that the torque is transmitted through elastic disk elements. It works by pulling and pushing segments with threads on a common bolt circle, which are screwed alternately between the input and output sides. An individual disc pack can compensate for angular and axial misalignment. Two-disc packs are required to accommodate parallel misalignment. 

Diaphragm Clutches 

Diaphragm Clutches also use thin foil as a flexible element as a disc clutch. These couplings handle misalignment by using a single or a series of parallel metal plates or flexible membranes for the flexible elements. It transmits torque from the OD of a flexible disk to the ID, through the coil and then from the ID to the OD. 

The OD side of the diaphragm bolts to the hub and the ID portion of the diaphragm disc fits into the slots on the spool portion, also known as spacers. At the other end of the coil, there is another diaphragm plate with a hub. Diaphragm couplings can accommodate all three misalignments. It can accommodate a larger range of axial misalignment. Originally introduced for high-power, very high-speed applications in the petrochemical industry, the diaphragm clutches have since evolved into other extreme applications such as helicopter propulsion. Diaphragm couplings are notorious for their large outside diameters and generally very high cost. Diaphragm couplings are typically sold as a custom solution and there are a variety of options to consider.