Investment casted strut drive & folding 3-blade aluminium-bronze propeller with shark-skin surface profile

现在有超过70%的人从在机动帆船上使用传统的水平轴驱动系统转向使用更现代的垂直支柱驱动系统。这一举措是由市场对竞争销售的低价“标价”的需求推动的。然而，如果垂直支柱的铝合金没有受到漆层的保护，从而接触到海水，支柱驱动系统就会受到腐蚀。如果安装了铝青铜推进器，促使海水发生电化学反应，情况尤其如此。铜基防污涂料目前正在使用，但对环境造成了破坏。此外，由于发动机的点火脉冲和螺旋桨叶片功率要求的周期性变化而造成的扭应力振荡，支柱传动系统容易发生故障。这个问题不是指从只对重复消费品销售感兴趣的制造商那里购买。根据经验和与船主的讨论，由于电化学腐蚀，船主似乎每两年可以花费约3800 GB更换和安装新的支柱和螺旋桨。Superprop Limited(SPL)建议开发一种精密铸造垂直支柱单元，该单元带有牺牲阳极和具有表面轮廓的铸造螺旋桨，以减少海洋污垢。组合后的装置将使用长达15年的寿命，通过减少阻力、提高性能和减少燃料消耗为船主节省大量资金。

There is now a greater than 70% move from using the conventional horizontal shaft driven systems on motorised sailing boats to using the more modern vertical strut-drive systems. This move is driven by the market need for a low “sticker price” for competitive selling. However, strut-drive systems suffer from corrosion if the aluminum alloy of the vertical strut becomes, in any way, unprotected by its paint layers such that it comes into contact with seawater. This is especially true if a propeller of aluminium bronze is fitted prompting a galvanic reaction through the sea water. Copper-based anti-foulant paint is currently used but is damaging to the environment. Also, the strut gearing system is prone to failure as a result of torsional stress oscillations that are set up due to the firing impulses of the engine and the cyclical variations in power requirements of the propeller blades. This issue is not alluded to on purchase from a manufacturer who is only interested in repeat consumable item sales. From experience and through discussions with boat owners it appears boat owners can spend up to around £3,800 every 2 years replacing and installing a new strut and propeller due to electrochemical corrosion. Superprop Limited (SPL) propose developing a precision cast vertical strut unit with sacrificial anode and a cast propeller with a surface profile to reduce marine fouling. The combined unit will have a service in life of up to 15 years with substantial saving for boat owners from reduced drag, enhanced performance and reduced fuel use.