Patent ID: 7361068

Claim:
A waterjet propulsion apparatus comprising: a housing having at least a water 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 and having a bearing cavity formed therein; a stator having a fluid inlet disposed adjacent the rotor, and a fluid outlet disposed downstream of the fluid inlet, the stator comprising a plurality of stator blades coupled to a stator hub, the stator hub spaced apart from the rotor hub to define a gap there between, and having a seal cavity formed therein that is in fluid communication with the gap; a bearing assembly housed within the bearing cavity; a lip seal assembly positioned between the seal cavity and the bearing cavity to at least inhibit water from entering the bearing cavity; and a seal pressure vent system defining a flow path that extends through at least a portion of the stator hub and includes at least an inlet and an outlet, the flow path inlet in fluid communication with the seal cavity, the flow path outlet in fluid communication with the stator fluid outlet.