Tip-driven propeller system needs no drive shaft or gearbox

摘要

Tom Shelley takes a look at a development in motors that is expected to revolutionise submersible vehicles, ships, pumps and micro hydroelectric power generation Thrusters, developed initially for underwater robot vehicles and now being extended to submersibles, are unique in that their propellers are driven from their tips, not by a central drive shaft. As well as making a much more compact device, they eliminate all the problems associated with having a motor, gearbox or pulley in front of the propeller, including any need for stuffing boxes or shaft seals. Larger sizes also does away with the need for heavy hydraulic systems. The systems therefore have huge potential as immersed pumps, thrusters for ships, possibly fans and as a method of producing small (and perhaps not so small) scale hydroelectric power from streams.