Regardless of etymology and spelling, tire or tyre couplings, are torsionally soft, shaft couplings with a flexible body that compensates misalignment and protects other components in the transmission system.
Couplings are mechanical components used to connect two in-line shafts to enable one shaft to drive another at the same speed. A coupling can be rigid or flexible, allowing various amount of angular, radial, and axial misalignment between the two shafts.