The new Hexaflex BlueLine shaft coupling brings a vibration free drive to work boats, yachts, leisure craft and small ships. Designed to fit easily between the diesel engine gearbox and the propeller shaft, the BlueLine is torsionally soft to dampen diesel vibrations and accept the misalignment from flexible engine mountings. Six sizes are available to fit most common engine gearbox configurations such as Yanmar, Volvo, Steyr, ZF and Techdrive with rated torques up to 2000Nm. The Hexaflex BlueLine is corrosion protected, maintenance free and has a very long service life.
With a propeller shaft in fixed bearings and the engine mounted on flexible vibration dampers generating their own oscillation behavior, the shaft coupling must be flexible and torsionally soft. The propeller shaft must not be affected by engine movements otherwise damage will occur, possibly resulting in a loss of drive. The Hexaflex BlueLine is designed to accept the misalignment and vibrations along with any thrust from the propeller to give a drive that is smooth and quiet.
The BlueLine coupling consists an input adaptor dimensioned to fit the gearbox flange, a flexible disc and a hub for the propeller shaft, together with bolt fixings. All metal parts are stainless or corrosion treated. The construction of the rubber flexible disc is notable. Unlike other coupling products, the torque is not transmitted through the synthetic rubber alone. Instead it is safely transmitted through a special arrangement of looped fibres located below the surface and giving a safety factor of 10. The strength of the flexible disc allows perfect centering of the drive even at high speeds and maximum misalignment.
The output hub connecting to the propeller shaft has a split clamp design that makes it easy to assemble and dismantle the coupling. No keyways or cone clamping elements are used and assembly can be done radially without disturbing the shaft or bearings. The two-piece hub design simply clamps to the shaft and transmits the torque by friction. All this saves time and frayed nerves in a narrow hull.
The new range of Hexaflex BlueLine marine couplings is already proven to remove noise and vibrating with a maintenance free long life. The synthetic fabric and rubber construction of the flexible disc readily accepts the misalignments from diesel gearbox to propeller shaft. In the UK BlueLine is available from the Techdrives division of Lenze Ltd, www.techdrives.co.uk, and enquiries for local distribution are welcome.