Innovative Solutions To Reduce The Transfer of Structure Borne Sound in Couplings 

Today's powertrains for marine applications are characterized by their high-power density in combination with the requirements for a light construction and the lowest possible acoustic transmission. This is no longer coupled only to military vessels or luxury yachts but is becoming more and more influential due to supra-regional laws.The primary structure-borne sound path is transmitted from the engine over the engine mounts into the ship's hull. This obvious path is currently already well attenuated and for the most part does not present noise vibration problems. Therefore, the secondary path from the engine via the coupling into the gearbox or the first main bearing and then into the ship's hull becomes more and more important. For this reason, torsionally flexible couplings and misalignment couplings are required, which can also minimize the transfer of structure borne sound while transmitting high torque levels. To fulfill all these partly contradictory demands, innovative approaches are essential. In this paper, the development of a lightweight misalignment coupling made of a combination of glass and carbon fibers, and elastomer layers will be presented. In combination with an optimized torsionally flexible couplings high acoustic requirements for marine drives can be met.