System and method for controlling the position of a levitated rotor

Patent metadata

Field	Value
Publication number	US-10874782-B2
Application number	US-201816218791-A
Country	US
Kind code	B2
Filing date	Dec 13, 2018
Priority date	Feb 12, 2015
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A rotary machine is provided which may include a rotor and a stator within a housing. The stator may be for generating a rotating magnetic field for applying a torque to the rotor. A commutator circuit may provide a plurality of phase voltages to the stator, and a controller may adjust the plurality of phase voltages provided by the commutator circuit to modify an attractive force of the stator on the rotor to move the rotor in an axial direction.

First claim

What is claimed is:

1. A blood pump, comprising:
a rotor disposed within a housing, wherein the housing defines one or both of hydrodynamic pressure grooves facing the rotor and a pump ring with a chamfered surface that are configured to cause a first axial force on the rotor;
a stator for:
applying a rotating magnetic field to the rotor; and
applying a second axial force on the rotor;

a controller for:
supplying phase voltages to the rotor; and
modifying the phase voltages provided to the stator to modify the second axial force such that the rotor is moved from a first balanced position to a second balanced position, wherein the second balanced position is different than the first balanced position.

2. The blood pump of claim 1 , wherein:
the housing comprises a first permanent magnet;
the rotor comprises a second permanent magnet; and
the housing being configured to cause the first axial force on the rotor further comprises
the first permanent magnet repulsing the second permanent magnet.

3. The blood pump of claim 1 , wherein the housing being configured to cause the first axial force on the rotor further comprises:
the housing being configured to circulate fluid about the rotor.

4. The blood pump of claim 3 , wherein:
the rotor defines hydrodynamic pressure grooves.

5. The blood pump of claim 1 , wherein the controller is further for:
determining an axial position of the rotor; and
modifying the second axial force based on the axial position of the rotor.

6. The blood pump of claim 1 , wherein modifying phase voltages comprises:
continuously modifying the phase voltages to move the rotor from the first balanced position to the second balanced position and to hold the rotor in the second balanced position.

7. The blood pump of claim 1 , wherein modifying phase voltages comprises:
periodically modifying the phase voltages to move the rotor from the first balanced position to the second balanced position and to hold the rotor in the second balanced position.

8. The blood pump of claim 1 , wherein modifying phase voltages comprises:
modifying the phase voltages in a single pulse to move the rotor from the first balanced position to the second balanced position.

9. The blood pump of claim 1 , wherein:
after the rotor has moved to the second balanced position, modifying the phase voltages is not required to maintain the stator in the second balanced position.

10. A non-transitory machine readable medium having instructions stored thereon, wherein the instructions, when executed, cause at least one processor to perform operations comprising:
determining an axial position of a rotor within a blood pump wherein the blood pump comprises a housing that defines one or both of hydrodynamic pressure grooves facing the rotor and a pump ring with a chamfered surface that are configured to cause a first axial force on the rotor;
causing a stator of the blood pump to apply a rotating magnetic field to the rotor;
causing the stator of the blood pump to apply a second axial force on the rotor; and
supplying phase voltages to the rotor; and
modifying the phase voltages provided to the stator to modify the second axial force such that the rotor is moved from a first balanced position to a second balanced position, wherein the second balanced position is different than the first balanced position.

11. The non-transitory machine readable medium of claim 10 , wherein determining the axial position of the rotor comprises:
determining at least one phase current; and
determining the axial position of the rotor based on the at least one phase current.

12. The non-transitory machine readable medium of claim 10 , wherein determining the axial position of the rotor comprises:
receiving a signal from a Hall sensor; and
determining the axial position of the rotor based on the signal.

13. The non-transitory machine readable medium of claim 10 , wherein determining the axial position of the rotor comprises:
receiving a signal from an optical sensor; and
determining the axial position of the rotor based on the signal.

14. The non-transitory machine readable medium of claim 10 , wherein modifying phase voltages comprises:
varying a commutation angle provided by a commutator circuit to the stator.

15. The non-transitory machine readable medium of claim 10 , wherein causing the stator of the blood pump to apply the rotating magnetic field to the rotor comprises:
using a field oriented control algorithm.

16. The non-transitory machine readable medium of claim 10 , wherein modifying phase voltages provided to the stator comprises:
continuously modifying the phase voltages to move the rotor from the first balanced position to the second balanced position and to hold the rotor in the second balanced position.

17. The non-transitory machine readable medium of claim 10 , wherein modifying phase voltages provided to the stator comprises:
periodically modifying the phase voltages to move the rotor from the first balanced position to the second balanced position and to hold the rotor in the second balanced position.

18. The non-transitory machine readable medium of claim 10 , wherein modifying phase voltages provided to the stator comprises:
modifying the phase voltages in a single pulse to move the rotor from the first balanced position to the second balanced position.

19. The non-transitory machine readable medium of claim 10 , wherein:
after the rotor has moved to the second balanced position, modifying the phase voltages is not required to maintain the stator in the second balanced position.

Assignees

• Tc1 Llc

Inventors

• Yu Shunzhou
• Medvedev Alexander
• You Ren

Classifications

• A61M60/824 Primary

  Hydrodynamic or fluid film bearings · CPC title

• A61M60/822

  specially adapted for being actively controlled · CPC title

• A61M60/538

  Regulation using real-time blood pump operational parameter data, e.g. motor current · CPC title

• A61M60/237

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

• A61M60/232

  Centrifugal pumps · CPC title