Patent ID: 7318759

Claim:
A waterjet propulsion apparatus comprising: a housing having at least a fluid intake section; and a pumping unit disposed within the housing and in fluidic communication with the water intake section, the pumping unit comprising: a rotor comprising a plurality of rotor blades coupled to a rotor hub; a bearing cartridge coupled to the rotor and having an initial ambient temperature preload condition, the bearing cartridge comprised of a plurality of bearing components; and a stator having a fluid inlet disposed adjacent the rotor, and a fluid outlet disposed downstream of the fluid inlet, wherein the bearing cartridge further includes a thermally insensitive solid bearing preload system comprising a bearing support system that is preloaded using a plurality of spacers comprising a retainer clamp spacer positioned to maintain a distance between the plurality of bearing components, a shaft spacer positioned to maintain a distance between the plurality of bearing components, and a clamping nut positioned a distance from one of the plurality of bearing components, the plurality of spacers configured to prevent relative motion between the plurality of bearing components that comprise the bearing cartridge and provide adjustment of the initial ambient temperature preload condition.