Rotodynamic pump having a body defining a body cavity with a first and second housing portion defining a portion of an impeller cavity and disposed within the body cavity wherein the body cavity extends at least in part around the second housing portion and the housing portions defining an impeller clearance

A rotodynamic pump for pumping a fluid, the rotodynamic pump comprising:

• a body defining a body cavity;
• an impeller disposed within the body cavity;
• a first housing portion disposed within the body cavity and defining at least in part an impeller cavity containing the impeller, and a second housing portion disposed within the body cavity and defining at least in part the impeller cavity, a portion of the body cavity defined between the second housing portion and the body, the portion of the body cavity fluidly sealed from the impeller cavity;
• and
• a pressure regulating mechanism configured to adjust a clearance between the impeller and the second housing portion to regulate pressure of the fluid downstream of the impeller;
• wherein the second housing portion is movable relative to the first housing portion during operation of the rotodynamic pump to vary the clearance, and the pressure regulating mechanism is configured to move the second housing portion relative to the first housing portion to vary the clearance and thereby regulate a delivery pressure of the fluid at an outlet of the pump;
• and
• wherein the body extends at least in part around the second housing portion, wherein an inner surface of the body and an outer surface of the second housing portion at least partially define the portion of the body cavity, the portion of the body cavity being hydraulically isolated from an outer surface of the body.