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Capacity modulation for plural compressors

Imported: 24 Feb '17 | Published: 06 Jan '04

Rajan Rajendran, John P. Sheridan, Carl H. Knapke

USPTO - Utility Patents

Abstract

A compressor system includes a pair of compressors located in a common shell. A common drive shaft drives both compressors and the drive shaft is powered by a single motor. One or both of the compressors can be equipped with a pulse width modulated capacity control system and a vapor injection system. When one compressor is equipped with these systems, the capacity can be varied between 50% and 110%. When both compressors are equipped with these systems, the capacity can be varied between 0% and 120%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a vertical cross sectional view through a motor-compressor system in accordance with the present invention;

FIG. 2 is a vertical cross sectional view of the motor compressor system shown in FIG. 1 with one of the two compressors incorporating pulse width modulation capacity control in accordance with the present invention;

FIG. 3 is an enlarged section view of the piston assembly shown in FIG. 2;

FIG. 4 is a top view of the discharge fitting shown in FIG. 3;

FIG. 5 is an end section view of the compressor shown in FIG. 2;

FIG. 6 is a side view of one of the non-orbiting scroll members shown in FIG. 2;

FIG. 7 is a cross sectional top view of the non-orbiting scroll member shown in FIG. 6;

FIG. 8 is an enlarged sectional view of the injection fitting shown in FIG. 2;

FIG. 9 is an end view of the fitting showing in FIG. 8;

FIG. 10 is a schematic diagram of a refrigerant system utilizing the capacity control system in accordance with the present invention;

FIG. 11 is a graph showing the capacity of the compressor using the capacity control system in accordance with the present invention; and

FIG. 12 is a vertical cross sectional view of the motor-compressor system shown in FIG. 1 with both of the two compressors incorporating pulse width modulation capacity control in accordance with the present invention.

Claims

1. A scroll machine comprising:

2. The scroll machine in accordance with claim 1, wherein said motor comprises:

3. The scroll machine in accordance with claim 1, wherein said first scroll compressor comprises:

4. The scroll machine in accordance with claim 3, wherein said mounting frame is disposed between said first main bearing housing and said shell.

5. The scroll machine in accordance with claim 3, wherein said second scroll compressor comprises:

6. The scroll machine in accordance with claim 5, wherein said mounting frame is disposed between said first main bearing housing and said shell and between said second main bearing housing and said shell.

7. The scroll machine in accordance with claim 1, wherein said shell defines a first discharge pressure chamber in communication with said first scroll compressor and a second discharge chamber in communication with said second scroll compressor.

8. The scroll machine in accordance with claim 7, wherein said first and second scroll compressors are disposed within said suction pressure chamber.

9. The scroll machine in accordance with claim 1, further comprising a first capacity modulation system for varying the capacity of said first scroll compressor.

10. The scroll machine in accordance with claim 9, wherein said first capacity modulation system includes a pulse width modulation system.

11. The scroll machine in accordance with claim 9, further comprising a second capacity modulation system for varying the capacity of said second scroll compressor.

12. The scroll machine in accordance with claim 11, wherein said first capacity modulation system includes a first pulse width modulation system and said second capacity modulation system includes a second pulse width modulation system.

13. The scroll machine in accordance with claim 1, wherein said motor is a variable speed motor.

14. The scroll machine in accordance with claim 1 wherein:

15. The scroll machine in accordance with claim 1 further comprising a first fluid injection fitting extending through said outer shell for implementing a first vapor injection system for said first scroll compressor.

16. The scroll machine in accordance with claim 15 further comprising a second fluid injection fitting extending through said outer shell for implementing a second vapor injection system for said second scroll compressor.

17. The scroll machine in accordance with claim 16, further comprising a first capacity modulation system for varying the capacity of said first scroll compressor.

18. The scroll machine in accordance with claim 17, wherein said first capacity modulation system includes a pulse width modulation system.

19. The scroll machine in accordance with claim 17, further comprising a second capacity modulation system for varying the capacity of said second scroll compressor.

20. The scroll machine in accordance with claim 19, wherein said first capacity modulation system includes a first pulse width modulation system and said second capacity modulation system includes a second pulse width modulation system.

21. The scroll machine in accordance with claim 15, further comprising a first capacity modulation system for varying the capacity of said first scroll compressor.

22. The scroll machine in accordance with claim 21, wherein said first capacity modulation system includes a pulse width modulation system.

23. The scroll machine in accordance with claim 21, further comprising a second capacity modulation system for varying the capacity of said second scroll compressor.

24. The scroll machine in accordance with claim 23, wherein said first capacity modulation system includes a first pulse width modulation system and said second capacity modulation system includes a second pulse width modulation system.

25. The scroll machine in accordance with claim 1 wherein said drive shaft includes a first eccentric crank pin and a second eccentric crank pin, said first and second crank pin defining a crank pin axis disposed eccentric from an axis of said drive shaft.

26. The scroll machine in accordance with claim 1 wherein a single suction inlet extends through said outer shell, said single suction inlet being in communication with said suction pressure zone.

27. The scroll machine in accordance with claim 1 further comprising a first oil pump in communication with said oil sump and said first scroll compressor.

28. The scroll machine in accordance with claim 27 further comprising a second oil pump in communication with said oil sump and said second scroll compressor.

29. The scroll machine in accordance with claim 1 wherein said outer shell comprises a generally cylindrical shell, a first end cap welded to one end of said generally cylindrical shell and a second end cap welded to an opposite end of said generally cylindrical shell.

30. A scroll machine comprising:

31. A scroll machine comprising:

32. The scroll machine according to claim 31, wherein said first fluid operated piston is operated in a time pulsed manner to modulate the capacity of said first scroll compressor.

33. The scroll machine according to claim 31, further comprising a fluid pressure chamber operative to apply said force to said first fluid operated piston.

34. The scroll machine according to claim 33, wherein said force acts in an axial direction.

35. The scroll machine according to claim 34, further comprising a first passage for supplying a pressurized fluid from said first scroll compressor to said pressure chamber.

36. The scroll machine according to claim 35, further comprising a valve for controlling flow through said first passage, said valve being operative to vent said pressurized fluid from said pressure chamber to thereby enable said second scrolls to move between said first and second relationships.

37. The scroll machine according to claim 36, wherein said valve is a solenoid operated valve.

38. The scroll-type machine according to claim 37, wherein said solenoid operated valve is operated in a pulse width modulated mode.

39. The scroll machine according to claim 35, further comprising a second passage for venting said pressurized fluid from said pressure chamber.

40. The scroll machine according to claim 31 wherein said fourth scroll member is movable between a first relationship in which sealing surfaces of said third and fourth scroll members are in sealing relationship to close off second fluid pockets and a second relationship wherein at least one of said sealing surfaces of said third and fourth scroll members are spaced apart to define a second leakage path between said second fluid pockets, and said scroll machine further comprises:

41. The scroll machine according to claim 40 further comprising: