Blood pump with magnetically loaded partial arc journal bearing

Patent metadata

Field	Value
Publication number	US-11872385-B2
Application number	US-201916980795-A
Country	US
Kind code	B2
Filing date	Mar 13, 2019
Priority date	Mar 14, 2018
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

A blood pump (10) includes a pump housing (30) having a pump inlet (16) and a pump outlet (18) spaced apart along a longitudinally extending central pump axis (28). The blood pump (10) also includes a rotating assembly (100) comprising an impeller (104). The blood pump (10) further includes partial arc journal bearings (160, 180) that support the rotating assembly (100) for rotation in the housing (30). The rotating assembly (100) is rotatable relative to the housing (30) to pump blood from the pump inlet (16) to the pump outlet (18).

First claim

I claim:

1. A blood pump comprising:
a pump housing having a pump inlet and a pump outlet spaced apart along a longitudinally extending central pump axis;
a rotating assembly comprising an impeller; and
partial arc journal bearings that support the rotating assembly for rotation in the housing, wherein the rotating assembly is rotatable relative to the housing to pump blood from the pump inlet to the pump outlet, wherein each of the partial arc journal bearings comprises a cylindrical journal component of the rotating assembly and a bushing component fixed to the housing, the bushing having a partial arc configuration extending partially around the circumference of the journal;
wherein the blood pump further comprises magnetic rings that help constrain axial movement of the rotating assembly relative to the housing, the magnetic rings being configured to exert a net radial force on the rotating assembly that pulls the journals into their associated bushings.

2. The blood pump recited in claim 1 , wherein:
the pump further comprises a stator assembly supported in the housing, the stator assembly comprising motor stator windings, a front magnetic bearing stator, and a rear magnetic bearing stator; and
the rotating assembly comprises motor rotor magnets that align axially with the motor stator windings, a front magnetic bearing rotor that aligns with the front magnetic bearing stator, and a rear magnetic bearing rotor that aligns with the rear magnetic bearing stator.

3. The blood pump recited in claim 2 , wherein the front and rear magnetic bearing stators each comprise one or more magnetic rings configured to produce a region of increased magnetic flux density on a bushing side of the pump, and wherein the front and rear magnetic bearing rotors comprise one or more magnetic rings in a full ring configuration, wherein the front and rear magnetic bearing stators are configured to act on the front and rear magnetic bearing rotors to exert a net radial force on the rotating assembly that pulls the rotating assembly into the partial arc journal bearings.

4. The blood pump recited in claim 3 , wherein the front and rear magnetic bearing stators comprise permanent magnet partial rings.

5. The blood pump recited in claim 4 , wherein the permanent magnet partial rings are positioned on the bushing side of the pump.

6. The blood pump recited in claim 2 , wherein the stator assembly comprises:
a stator housing;
a motor stator supported in the stator housing;
front magnetic bearing stator magnetic rings mounted on the stator housing in front of the motor stator; and
rear magnetic bearing stator magnetic rings mounted on the stator housing to the rear of the motor stator.

7. The blood pump recited in claim 1 , wherein the pump housing comprises an inner housing and an outer housing between which an axially extending primary flow channel is defined, the blood pump being configured to pump blood through the primary flow channel.

8. The blood pump recited in claim 7 , wherein the primary flow channel is annular and extends outside the stator assembly and the rotating assembly.

9. The blood pump recited in claim 7 , further comprising helical flow straightening vanes that extend between the inner and outer housings in the primary flow channel.

10. The blood pump recited in claim 1 , wherein the magnetic rings maintain the axial position of the rotating assembly in the housing.

11. The blood pump recited in claim 1 , wherein the magnetic rings comprise one or more magnets configured to produce a region of increased magnetic flux density that pulls the rotating assembly into the partial arc journal bearings.

12. The blood pump recited in claim 1 , wherein the rotating assembly comprises:
a rotor shaft;
an impeller mounted toward a front end portion of the rotor shaft;
front magnetic bearing rotor magnet rings mounted on the rotor shaft adjacent the impeller;
the motor rotor magnets being mounted on the rotor shaft adjacent the impeller front magnetic bearing rotor magnet rings; and
rear magnetic bearing rotor magnet rings mounted on the rotor shaft adjacent the motor rotor magnets;
wherein a front end portion of the rotor shaft extending forward of the impeller defines a front journal of the front partial arc journal bearing, and wherein a rear end portion of the rotor shaft extending rearward of the rear magnetic bearing rotor magnet rings defines a rear journal of the rear partial arc journal bearing.

13. The blood pump recited in claim 1 , wherein the bushings extend radially 90-300 degrees around the circumference of their associated journals.

14. The blood pump recited in claim 1 , wherein the bushings are aligned with each other radially about the pump axis.

15. The blood pump recited in claim 1 , wherein the centers of the partial arcs of the bushings are positioned on the pump axis.

16. The blood pump recited in claim 1 , wherein the front partial arc journal bearing is positioned in the pump inlet and the rear partial arc journal bearing is positioned in the pump outlet.

17. The blood pump recited in claim 1 , wherein the partial arc journal bearings are configured such that the partial arcs of the bushings are radially aligned with the magnetic rings.

18. A blood pump comprising:
a pump housing having a pump inlet and a pump outlet spaced apart along a longitudinally extending central pump axis;
a rotating assembly comprising an impeller; and
partial arc journal bearings that support the rotating assembly for rotation in the housing, wherein the rotating assembly is rotatable relative to the housing to pump blood from the pump inlet to the pump outlet, wherein each of the partial arc journal bearings comprises a cylindrical journal component of the rotating assembly and a bushing component fixed to the housing, the bushing having a partial arc configuration extending radially 90-300 degrees around the circumference of their associated journals.

19. The blood pump recited in claim 18 , wherein:
the pump further comprises a stator assembly supported in the housing, the stator assembly comprising motor stator windings, a front magnetic bearing stator, and a rear magnetic bearing stator; and
the rotating assembly comprises motor rotor magnets that align axially with the motor stator windings, a front magnetic bearing rotor that aligns with the front magnetic bearing stator, and a rear magnetic bearing rotor that aligns with the rear magnetic bearing stator.

20. The blood pump recited in claim 19 , wherein the front and rear magnetic bearing stators each comprise one or more magnetic rings configured to produce a region of increased magnetic flux density on a bushing side of the pump, and wherein the front and rear magnetic bearing rotors comprise one or more magnetic rings in a full ring configuration, wherein the front and rear magnetic bearing stators are configured to act on the front and rear magnetic bearing rotors to exert a net radial force on the rotating assembly that pulls the rotating assembly into the partial arc journal bearings.

21. The blood pump recited in claim 20 , wherein the front and rear magnetic bearing stators comprise permanent magnet partial rings.

22. The blood pump recited in claim 21 , wherein the permanent magnet partial rings are positioned on the bushing side of the pump.

23. The blood pump recited in claim 19 , wherein the stator assembly comprises:
a stator housing;
a motor stator supported in the stator housing;

Assignees

• Cleveland Clinic Found

Inventors

• Smith William

Classifications

• A61M60/82 Primary

  Magnetic bearings · CPC title

• A61M60/148

  in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices · CPC title

• A61M60/178

  drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices · CPC title

• A61M60/237

  the blood flow through the rotating member having mainly axial components, e.g. axial flow pumps · CPC title

• A61M60/422

  the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps · CPC title