Development of novel folding propeller for sailing yachts

根据Sailing Today杂志（2011年9月），已知固定叶片螺旋桨在航行时可以将速度降低0.5- 1.0节。因此，许多帆船拥有者使用折叠螺旋桨，因为它们最大限度地减少了帆船上引起的不必要的阻力。尽管折叠式螺旋桨在市场上占据主导地位，但折叠式螺旋桨仍存在许多问题，使其无法完全满足航海消费者的需求。首先，折叠式螺旋桨在设计寿命结束前就有工作部件丢失的名声，这使得船主需要更换设备。已知现有螺旋桨的重量会影响轴支撑联轴器中无切口橡胶轴承的寿命。最后，由于反向推力不足，在码头或泊位内或附近操纵变得更加危险。折叠螺旋桨的价格可能比标准固定叶片高出3倍。Super Prop Ltd.是一家初创公司，旨在开发能够生产新型螺旋桨的专业加工技术，以解决上述客户问题。他们的概念解决方案是通过Micro Metalsmiths Ltd. 30多年来开发的专业熔模铸造方法实现的。SuperProp螺旋桨的重量比竞争对手轻30%，成本降低50%，平均寿命延长约25%，并将产生更大的推力，具有复杂的叶片形状，这是非常困难的生产通过正常的数控加工方法。

According to Sailing Today Magazine (Sep 2011), fixed blades propellers are known toreduce speed “under sail” by a considerable 0.5-1.0knots. Therefore, many sail boat ownersuse folding propellers, as they minimise the unwanted drag induced on a sailing boat. Despitethe predominance of folding propellers in the market, there are a number of issues associatedwith the folding propeller that prevent it from fully satisfying the needs of the sailingconsumer.Firstly, folding propellers have a reputation for losing working parts before the end of theirdesign life, leaving the boat owner needing a replacement device. The weight of existingpropellers is known to affect the life of the cutless rubber bearings contained in the shaftsupport coupling. Finally, since reverse thrust is less than adequate, manoeuvring within orclose to a marina or a berth becomes significantly more treacherous. Folding propellers can beup to 3 times more expensive than standard fixed blade.Super Prop Ltd. is a start-up company, set up to exploit specialist processing technologycapable of producing a novel propeller that can address the aforementioned customer issues.Their concept solution is enabled through a specialist investment casting method developedover 30years by Micro Metalsmiths Ltd. The SuperProp propeller will weigh 30% less than itscompetitors, cost 50% less, have an average extended life of approximately 25%, and willproduce more thrust by having a complex blade shape that is extremely difficult to produce bynormal CNC machining methods.