Water jet propulsion unit for use in water borne craft

摘要

A water jet propulsion unit suitable for use in outboard or stern-drive configuration in motor boats. The unit has an intake section, a pump section and a drive section within which is incorporated a pressure control device and nozzle. In the pump section there are two counter-rotating impellers on concentric counter-rotating shafts. The impellers are mounted upstream of the drive section. The drive section contains a drive transmission carrier to which is attached the pressure control device both being located in the vortex created in the water flow, downstream of the two impellers. The pressure control device allows the propulsion unit to operate in a low pressure high mass mode while maintaining pump priming. The impellers can be removed without disassembly of the drive transmission carrier.