Patent ID: 11904155
Assignee: STAR BP, INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A heart assist apparatus, comprising:
a pump housing having a first end and a second end;
a rotor retained within said pump housing;
said rotor comprising a shaft with an outer surface and an impeller extending from the shaft at a first location on the outer surface at a proximal end of said rotor at the first end of said pump housing;
said outer surface of said rotor comprising an outer bearing surface at a second location on the shaft with a radial bearing at or adjacent to the outer bearing surface comprising a plain-sleeve radial journal bearing surface;
an axial bearing comprising a hemispherical surface or conical surface disposed axially adjacent a leakage inlet of said pump housing at a distal end of said rotor at the second end of said pump housing and having a plurality of grooves configured for promoting blood flow into a leakage flow path from the leakage inlet;
said pump housing comprising one or more cylindrical bores configured to define a pumping chamber and an inner bearing surface within the pump housing and a radial port disposed between the pumping chamber and the inner bearing surface;
wherein, in an operating configuration, the impeller rotates within the pumping chamber upon actuation of the rotor to draw a first flow of blood inward from the radial port into the pumping chamber;
wherein rotation of the impeller draws a second flow of blood through an axial port, as the leakage inlet, disposed at the second end of the pump housing, into the pumping chamber along the length of the inner bearing surface through a leakage flow path in fluid communication with an annular clearance between the inner bearing surface and outer bearing surface; and
wherein said inner bearing surface of the pump housing is closely fitted to said outer bearing surface of said shaft to form the annular clearance there between such that during actuation of the rotor the inner bearing surface and outer bearing surface form a hydrodynamic journal bearing.