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

现在有一个大于70%的移动从使用传统的水平轴驱动系统的机动帆船使用更现代化的垂直支柱驱动系统。这一举措是由市场需要一个低的“标签价格”的竞争性销售。然而，如果垂直支柱的铝合金以任何方式变得不受其油漆层保护，使得其与海水接触，则支柱驱动系统遭受腐蚀。如果安装了铝青铜螺旋桨，通过海水产生电流反应，情况尤其如此。目前使用铜基防污漆，但对环境有害。而且，由于发动机的点火脉冲和螺旋桨叶片的功率需求的周期性变化而建立的扭转应力振荡，支柱传动系统易于失效。从只对重复消耗品销售感兴趣的制造商处购买时，未提及此问题。根据经验和与船主的讨论，由于电化学腐蚀，船主每两年可能会花费约3，800英镑更换和安装新的支柱和螺旋桨。Superprop有限公司（SPL）建议开发一种带有牺牲阳极的精密铸造垂直支柱装置和一种具有表面轮廓的铸造螺旋桨，以减少海洋污染。该组合装置的使用寿命将长达15年，可为船主节省大量费用，减少阻力，提高性能和减少燃料使用。

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.