Novel Low Cost Thin Ply Composite Shafting for Power Transmission

Air Cushion Vehicles (ACV) utilize steel shafts to transmit power to propeller and lift fans. Shafts are exposed to severe environments including constant salt spray, sand particles, and extreme dynamic loading. The next generation ACV, Joint Maritime Assault Connector (JMAC), will require greater lift capacity, with power transmission needs increasing up to 65%. Scaling current steel shafts to accommodate increased JMAC requirements would add considerable weight, unacceptably reducing useful payload. During Phase I KaZaK identified two different design and manufacturing approaches for making composite replacements for the two sets of six different shaft configurations used on the current LCAC. Depending on individual shaft details, some LCAC shafts are most appropriately made with a conventional shaft/coupling arrangement, while others can benefit from an integrated shaft/coupling solution. Both approaches save more than 50% weight, and are estimated to be approximately the same acquisition cost as baseline steel. Life cycle costs should be lower. Phase II funding is sufficient for the KaZaK team to design, fabricate, test and deliver examples of four of the six LCAC shafts. Because they are easily installed and removed, composite shafting provides a low risk path to significant weight and cost reduction in current and future ACVs.