Progressive cavity pump including a bearing between the rotor and stator

1. A progressive cavity pump comprising:

a stator, the stator including a helical shaped interior with a first pitch;

a rotor inside the stator, the rotor including a helical shaped exterior with a second pitch, wherein the second pitch is different from the first pitch, wherein the rotor is effective to rotate with respect to the stator and effective to move eccentrically within the stator to define at least one cavity inside the stator; and

a first bearing and a second bearing between the rotor and the stator, wherein the first and second bearings are sized and shaped so that the rotor is effective to rotate inside the first and second bearings and the first and second bearings are effective to move eccentrically along with the rotor; and

a thrust bearing disposed on the rotor and in mechanical communication with a spring wherein the spring is effective to bias the first bearing toward the second bearing.

2. The progressive cavity pump of claim 1 , wherein the thrust bearing is a first thrust bearing and the spring is a first spring, the progressive cavity pump further comprising:

the first thrust bearing disposed at a first end of the rotor; and

a second thrust bearing in mechanical communication with a second spring disposed at a second end of the rotor distal from the first end; wherein

the first and second springs are effective to bias the first bearing toward the second bearing.

3. The progressive cavity pump of claim 1 , wherein the thrust bearing is a first thrust bearing and the spring is a first spring, the progressive cavity pump further comprising:

a first pin engaged with a first end of the rotor;

the first thrust bearing in mechanical communication with the first pin;

a second pin engaged with a second end of the rotor distal from the first end;

a second thrust bearing in mechanical communication with the second pin; and

a second spring in mechanical communication with the second thrust bearing and in mechanical communication with the second bearing, wherein the first and second springs are effective to bias the first bearing toward the second bearing.

4. The progressive cavity pump of claim 1 , wherein the first and/or second bearing is a hollow cylinder.

5. The progressive cavity pump of claim 1 , wherein:

the first and/or second bearing is a hollow cylinder; and

the first and/or second bearing is effective to rotate about the rotor when the respective first and/or second bearing engages the interior of the stator.

6. The progressive cavity pump of claim 1 , wherein the first and/or second bearing is a hollow rectangular solid.

7. The progressive cavity pump of claim 1 , wherein:

the first and/or second bearing is a hollow rectangular solid; and

a surface of the first and/or second bearing is effective to slide against the interior of the stator upon rotation and eccentric movement of the rotor.

8. The progressive cavity pump of claim 1 , wherein the first and/or second bearing is made of a metal or metal alloy.

9. The progressive cavity pump of claim 1 , wherein the first and/or second bearing is made of a Fe—C—X multi-component alloy system where X represents chromium, tungsten, molybdenum, vanadium, or cobalt.

10. The progressive cavity pump of claim 1 , wherein the thrust bearing is a first thrust bearing and the spring is a first spring, the progressive cavity pump further comprising:

a first pin engaged with a first end of the rotor;

the first thrust bearing in mechanical communication with the first pin;

a second pin engaged with a second end of the rotor distal from the first end;

a second thrust bearing in mechanical communication with the second pin; and

a second spring in mechanical communication with the second thrust bearing and in mechanical communication with the second bearing, wherein the first and second springs are effective to bias the first bearing toward the second bearing;

the first and second bearings are a hollow rectangular solids; and

a surface of the first and second bearings is effective to slide against the interior of the stator upon rotation and eccentric movement of the rotor.

11. A method of making a progressive cavity pump, the method comprising:

providing a stator, wherein the stator includes a helical shaped interior with a first pitch;

providing a rotor, wherein the rotor includes a helical shaped exterior with a second pitch, wherein the second pitch is different from the first pitch;

placing a first bearing on the rotor;

placing a second bearing on the rotor;

placing a thrust bearing on the rotor, the thrust bearing in mechanical communication with a spring wherein the spring is effective to bias the first bearing toward the second bearing;

placing the rotor, the first and second bearings, the thrust bearing and the spring inside the stator;

wherein

the rotor is effective to rotate with respect to the stator and effective to move eccentrically within the stator to define at least one cavity inside the stator; and

the first and second bearings are sized and shaped so that the rotor is effective to rotate inside the first and second bearings and the first and second bearings are effective to move eccentrically along with the rotor.

12. The method of claim 11 , wherein the thrust bearing is a first thrust bearing and the spring is a first spring, the method further comprising:

placing the first thrust bearing on a first end of the rotor; and

placing a second thrust bearing in mechanical communication with a second spring at a second end of the rotor distal from the first end; wherein

the first and second springs are effective to bias the first bearing toward the second bearing.

13. The method of claim 11 , wherein:

the first and/or second bearing is a hollow cylinder; and

the first and/or second bearing is effective to rotate about the rotor when the respective first and/or second bearing engages the interior of the stator.

14. The method of claim 11 , wherein:

the first and/or second bearing is a hollow rectangular solid; and

a surface of the first and/or second bearing is effective to slide against the interior of the stator upon rotation of the rotor.

15. A method of using a progressive cavity pump, the method comprising:

rotating a rotor inside, and with respect to, a stator to move the rotor eccentrically within the stator and to define at least one cavity inside the stator, wherein the stator includes a helical interior surface with a first pitch, and the rotor includes a helical exterior surface with a second pitch, wherein the second pitch is different from the first pitch, engaging an exterior surface of a first bearing against the helical interior surface of the stator;

engaging an exterior surface of a second bearing against the helical interior surface of the stator;

engaging an interior surface of the first bearing with the rotor;

engaging an interior surface of the second bearing with the rotor;

wherein a spring in mechanical communication with a thrust bearing on the rotor is effective to bias the first bearing toward the second bearing; and

eccentrically moving the first and second bearings along with the rotor.

16. The method of claim 15 , further comprising:

applying a fluid to the cavity; and

moving the fluid from a first end of the pump to a second end of the pump.

17. The method of claim 15 , wherein:

the first and/or second bearing is a hollow cylinder; and

the first and/or second bearing is effective to rotate about the rotor when the respective first and/or second bearing engages the interior of the stator.

18. The method of claim 15 , wherein:

the first and/or second bearing is a hollow rectangular solid; and

a surface of the first and/or second bearing is effective to slide against the interior of the stator upon rotation of the rotor.