Comparison of piston and tangential pneumatic flexible shaft couplings in terms of high flexibility

The optimal tuning of mechanical systems in terms of torsional vibration magnitude is a very important function in flexible shaft couplings. Therefore, a flexible coupling with suitable dynamic properties, particularly dynamic torsional stiffness, has to be carefully chosen for each specific application. The current trend in the field of flexible shaft couplings, and the most noticeable in the automotive industry, is the development and utilization of highly flexible couplings, which means flexible couplings with a very low value of relative torsional stiffness. The aim of this article is to introduce a new type of flexible shaft coupling: a piston pneumatic flexible shaft coupling. This coupling was developed to improve the properties of pneumatic flexible couplings, especially the maximum angle of twist, in order to create a highly flexible pneumatic coupling. For illustration purposes, the piston pneumatic coupling is compared with the tangential pneumatic flexible shaft coupling of Type 3-1/110-T-C in terms of high flexibility characteristics, whereby the characteristic dimensions of both couplings are the same. Given that the piston pneumatic coupling has not been manufactured to date, only a computational model of this coupling was used. The results show that the design of the piston pneumatic flexible shaft coupling combines the advantages of a highly flexible and pneumatic shaft coupling.