Sealless rotodynamic pump with radially offset rotor

Claim 2

A rotodynamic pump comprising: a housing having an axis and an inlet and outlet in fluid communication with a chamber; a rotor having an impeller received in the chamber; drive means for rotating the rotor relative to the housing including a drive element and a driven element operatively associated with the rotor, the driven element being radially offset/displaced relative to the axis of the drive housing to produce a predetermined radial force of known magnitude and direction; fluid bearing means for supporting the rotor in the chamber provided by an extension of an end wall of the chamber; and means for continually renewing the fluid in contact with all wetted surfaces of the chamber.

Claim 3

The pump as defined in claim 1 further comprising first and second generally radially spaced circumferentially continuous fluid flow passages defined between the housing and the rotor.

Claim 4

The pump as defined in claim 2 further comprising means for urging fluid flow through the second passage.

Claim 5

The pump as defined in claim 2 further comprising first and second blade sets operatively associated with the rotor, the first blade set pumping fluid from the inlet to the outlet, and the second blade set urging fluid through the second passage.

Claim 6

The pump as defined in claim 2 further comprising an opening in the rotor connecting the first and second passages for permitting fluid flow therebetween.

Claim 7

The pump as defined in claim 2 wherein the second passage has a narrowed portion to define a fluid bearing of the fluid bearing means.

Claim 8

The pump as defined in claim 6 further comprising a groove on a sidewall of the second passage for passing flow through the fluid bearing.

Claim 9

The pump as defined in claim 6 wherein the second passage has a second narrowed portion to define a second fluid bearing of the fluid bearing means.

Claim 10

The pump as defined in claim 8 further comprising a groove on a sidewall of the second passage for passing flow through the second fluid bearing.

Claim 11

The pump as defined in claim 1 further comprising a set of blades on the rotor for urging fluid flow through the fluid bearing means.

Claim 12

The pump as defined in claim 10 further comprising thrust reaction means operatively associated with the drive and driven elements for resisting longitudinal displacements caused by axial fluid, gravitational, inertial or other forces.

Claim 13

The pump as defined in claim 1 further comprising means for limiting axial travel of the rotor relative to the housing.

Claim 14

The pump as defined in claim 1 wherein the longitudinal axis of the rotor housing is offset relative to the longitudinal axes of the drive element and the drive housing to more closely align the rotor housing axis with the rotor axis of rotation during operation.

Claim 15

The pump as defined in claim 1 wherein the drive means comprises an electric motor having a rotor portion and a stator portion.

Claim 16

The pump as defined in claim 1 wherein the drive means comprises an electric motor with a stator portion smaller in diameter than a rotor portion.

Claim 17

The pump as defined in claim 1 wherein the drive means comprises a magnetic coupling in combination with a prime mover.

Claim 18

The pump as defined in claim 1 further comprising blood as the fluid.

Claim 19

A rotodynamic pump comprising: a housing having an axis and an inlet and an outlet in fluid communication with a chamber; a shaftless rotor received in the chamber for selective rotation relative to the housing; drive means for rotating the rotor relative to the housing including a drive element having an axis and a driven element operatively associated with the rotor, the axis of the drive element being radially displaced relative to the axis of the housing to produce a radial force of known magnitude and direction; a fluid bearing means defined between the rotor and the housing; and means for continually renewing the fluid in contact with all wetted surfaces on the chamber.

Claim 20

A rotodynamic pump comprising: a housing having an axis and an inlet and an outlet in fluid communication with a chamber; a shaftless rotor received in the chamber for selective rotation relative to the housing; drive means for rotating the rotor relative to the housing including a drive element having an axis and a driven element operatively associated with the rotor, the axis of the drive element being radially displaced relative to the axis of the housing to produce a radial force of known magnitude and direction; a fluid bearing means defined between the rotor and the housing; and means for continually renewing the fluid in contact with all wetted surfaces on the chamber.

Claim 21

The pump as defined in claim 18 further comprising first and second radially spaced continuous flow passages defined between the rotor and the housing.

Claim 22

The pump as defined in claim 19 further comprising an opening through the rotor connecting the first and second passages for permitting flow therebetween.

Claim 23

The blood pump as defined in claim 19 wherein the rotor includes first and second sets of blades, the first blade set disposed in the first passage to pump fluid from the inlet to the outlet.

Claim 24

The pump as defined in claim 21 wherein the second blade set scavenges fluid from the second passage to enhance fluid through flow.

Claim 25

The blood pump as defined in claim 19 wherein the second passage is narrowed at one end to define a fluid bearing.

Claim 26

The pump as defined in claim 23 further comprising a groove in a side wall of the second passage to increase the area for flow through the fluid bearing.

Claim 27

The pump as defined in claim 23 wherein the second passage is narrowed at the other end to define a second fluid bearing.

Claim 28

The pump as defined in claim 25 further comprising a groove in a side wall of the second passage to increase the area for flow through the fluid bearing.

Claim 29

The pump as defined in claim 18 wherein the drive means includes an electric motor stator and winding in the housing portion and a surrounding permanent magnet assembly in the rotor.

Claim 30

The pump as defined in claim 18 wherein the magnetic attraction of the drive and driven elements of the rotating means define a thrust reaction means to resist longitudinal displacements caused by axial fluid, gravitational inertial or other forces.

Claim 31

The pump as defined in claim 18 further comprising means for limiting axial travel of the rotor relative to the housing.

Claim 32

The pump as defined in claim 29 wherein the limiting means includes a contact surface adapted to selectively contact the rotor.

Claim 33

The pump as defined in claim 18 wherein the housing includes a rotor housing a a motor housing each having its own axis, the axis of the rotor housing is radially displaced relative to the axes of the drive element of the drive means and the motor housing to provide closer alignment of a rotor housing axis with the rotor axis of rotation during operation.

Claim 34

The pump as defined in claim 18 wherein the drive means comprises a magnetic coupling in combination with a prime mover.

Claim 35

The pump as defined in claim 18 further comprising blood as the working fluid.

Claim 36

A rotodynamic blood pump comprising: a housing having an inlet and an outlet in fluid communication with a chamber, the housing including a housing portion that extends axially inward to the chamber from an end wall; an annular rotor receive in the chamber around the housing portion for selective rotation relative to the housing, the rotor being spaced from the housing and housing portion to define radially spaced first and second passages, the first passage extending between the inlet and outlet and containing an impeller blade set on the rotor for urging flow form the inlet to the outlet, and the second passage being narrowed at first and second ends to form fluid bearings; drive means for rotating the rotor relative to the housing including a ferromagnetic assembly received in the rotor and an electric motor stator and winding assembly installed in the housing and radially coupled to the ferromagnetic assembly in the rotor, an axis of the motor stator being radially displaced relative to an axis of the housing to produce a radial force of known magnitude and direction; and means for continually renewing the blood in contact with all wetted surfaces of the chamber.

Claim 37

A rotodynamic blood pump comprising: a housing having an inlet and an outlet in fluid communication with a chamber, the housing including a housing portion that extends axially inward to the chamber from an end wall; an annular rotor receive in the chamber around the housing portion for selective rotation relative to the housing, the rotor being spaced from the housing and housing portion to define radially spaced first and second passages, the first passage extending between the inlet and outlet and containing an impeller blade set on the rotor for urging flow form the inlet to the outlet, and the second passage being narrowed at first and second ends to form fluid bearings; drive means for rotating the rotor relative to the housing including a ferromagnetic assembly received in the rotor and an electric motor stator and winding assembly installed in the housing and radially coupled to the ferromagnetic assembly in the rotor, an axis of the motor stator being radially displaced relative to an axis of the housing to produce a radial force of known magnitude and direction; and means for continually renewing the blood in contact with all wetted surfaces of the chamber.

Claim 38

The blood pump as defined in claim 34 wherein the magnetic attraction of the motor stator and ferromagnetic assembly defines a thrust reaction means to resist longitudinal displacements caused by axial fluid, gravitational, inertial or other forces.

Claim 39

The blood pump as defined in claim 34 wherein one end of the annular rotor is conically narrowed and cooperates with strut means on the rotor housing for limiting axial travel of the rotor relative to the housing.

Claim 40

The blood pump as defined in claim 34 further comprising means for urging blood flow through the second passage independent of the flow in the first passage.

Claim 41

The blood pump as defined in claim 34 further comprising a second blade set on the rotor for urging flow through the second passage.

Claim 42

The blood pump as defined in claim 34 further comprising an opening in the annular rotor connecting the first and second passages for permitting blood flow therebetween.

Claim 43

The blood pump as defined in claim 34 further comprising plural spaced grooves on the housing portion adjacent first and second ends of the second passage for increasing flow area through the fluid bearings.

Claim 44

The pump as defined in claim 40 wherein the the axis of the housing is radially displaced relative to the axes of the motor stator and the housing portion to provide closer alignment of the housing axis with the rotor axis of rotation during pumping.