US20090116977A1

US20090116977A1 - Compressor With Muffler

Info

Publication number: US20090116977A1
Application number: US12/259,758
Authority: US
Inventors: Michael M. Perevozchikov; Roy J. Doepker
Original assignee: Individual
Current assignee: Copeland LP
Priority date: 2007-11-02
Filing date: 2008-10-28
Publication date: 2009-05-07
Also published as: CN101429940B; FR2923872A1; CN101429940A

Abstract

A compressor assembly may include a shell, a discharge fitting, a muffler, a compression mechanism, and a motor. The shell may have an opening therethrough with the discharge fitting generally extending therefrom. The muffler may be in communication with the discharge fitting and may be external to the shell. The muffler may have an inlet proximate the discharge fitting, an outlet distal from the discharge fitting, and a body portion extending therebetween. The muffler may include a valve assembly proximate the outlet. The compression mechanism may be contained within the shell and include a suction inlet and a discharge passageway. The discharge passageway may be connected to the opening in the shell for direct discharge of refrigerant from the compression mechanism to the discharge fitting. The motor may be contained within the shell and drivingly coupled to the compression mechanism.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/984,908, filed on Nov. 2, 2007. The entire disclosure of the above application is incorporated herein by reference.

FIELD

The present disclosure relates to scroll compressors, and more specifically to scroll compressor having mufflers.

BACKGROUND AND SUMMARY

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Direct discharge refrigerant compressors for cooling systems such as air conditioning, refrigeration or chiller systems, may include an external muffler to reduce a discharge pressure pulse and/or noise. These compressors may also include a device to prevent backflow during shutdown in order to prevent motor damage. When the compressor is shut down, the compression mechanism is at a lower pressure than the discharge fitting and the external muffler. Without backflow prevention, refrigerant reverses direction in the high-pressure region of the discharge fitting and flows into the compression mechanism. This backflow may cause the compression mechanism to operate in reverse, resulting in noise and potential motor damage.
A compressor assembly includes a shell, a discharge fitting, a muffler, a compression mechanism, and a motor. The shell includes an opening therethrough with the discharge fitting generally extending therefrom. The muffler is in communication with the discharge fitting and may be external to the shell. The muffler includes an inlet proximate the discharge fitting, an outlet distal from the discharge fitting, and a body portion extending therebetween. The muffler may include a valve assembly proximate the outlet. The compression mechanism may be contained within the shell and include a suction inlet and a discharge passageway. The discharge passageway may be connected to the opening in the shell for direct discharge of refrigerant from the compression mechanism to the discharge fitting. The motor may be contained within the shell and drivingly coupled to the compression mechanism.
The first valve assembly may be located within the body portion of the muffler.
In a variation, the first valve assembly may be contained within the outlet of the muffler. The outlet includes a first portion internal to the body portion and a second portion external to the body portion. The first valve assembly may be located within the second portion of the outlet. In an alternate arrangement, the first valve assembly may be located within the first portion of the outlet. The outlet may include a tubular member secured to the muffler body portion, a valve seat secured to the tubular member, and a valve stop. The valve seat and the valve stop define a valve chamber. The valve assembly may include a valve member disposed within the valve chamber and movable between a closed position where the valve member abuts the valve seat and an open position where the valve member abuts the valve stop.
The compressor may additionally include a second valve assembly disposed between the discharge passageway and the first valve assembly. The first valve assembly may be configured to move to a closed position when a direction of flow is from the outlet to the inlet. The closed position may generally prevent flow from passing from the outlet to the inlet. The first valve assembly may be configured to move to an open position when a direction of flow is from the inlet to the outlet. The open position may generally allow flow to pass from the inlet to the outlet.
The compression mechanism may include first and second scroll members meshingly engaged with one another to form a plurality of intermediate compression pockets and a discharge pocket. A first and second of the intermediate pockets immediately adjacent to the discharge pocket define a compression volume immediately prior to communication between the first and second intermediate pockets and the discharge pocket. A ratio between a total volume of the muffler and the compression volume may be between 5-to-1 and 20-to-1. A ratio between a cross-sectional area of the muffler taken generally perpendicular to a fluid flow direction therethrough and a cross-sectional area of the inlet may be greater than 20-to-1.
Further, the first valve assembly may be biased to an open position by gravity.
In another arrangement, a compressor assembly may include a compressor having a discharge fitting extending therefrom and a muffler assembly. The muffler assembly may include a muffler having an inlet, an outlet, and a body portion disposed between the inlet and the outlet. The inlet is in communication with the discharge fitting. At least a portion of the inlet may be external to the compressor and the outlet may have a valve assembly contained therein.
The outlet includes a first portion internal to the body portion and a second portion external to the body portion. The valve assembly may be located within the second portion of the outlet. Alternatively, the valve assembly may be located within the first portion of the outlet. The outlet may include a tubular member secured to the muffler body portion, a valve seat secured to the tubular member, and a valve stop. The valve seat and the valve stop define a valve chamber. The valve assembly includes a valve member disposed within the valve chamber and moveable between a closed position where the valve member abuts the valve seat and an open position where the valve member abuts the valve stop.
Further, the valve assembly may be biased to an open position by gravity.
A direct discharge compressor muffler may include an inlet, an outlet, a body portion disposed between the inlet and outlet, and a valve assembly. The valve assembly may be contained within the muffler and proximate the outlet. The valve assembly is configured to prevent flow from passing in a direction from the inlet to the outlet.
The valve assembly may be contained within the outlet. The outlet includes a first portion internal to the body portion and a second portion external to the body portion. The valve assembly may be located within the second portion of the outlet. Alternatively, the valve assembly may be located within the first portion of the outlet. The outlet may include a tubular member secured to the muffler body portion, a valve seat secured to the tubular member, and a valve stop. The valve seat and the valve stop define a valve chamber. The valve assembly includes a valve member disposed within the valve chamber and moveable between a closed position where the valve member abuts the valve seat and an open position where the valve member abuts the valve stop.
The valve assembly may be located within the body portion. The valve assembly may be biased to an open position by gravity.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present claims.

DRAWINGS

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the teachings in any way.

FIG. 1 is a section view of a compressor and muffler assembly;

FIG. 2 is a section view of the compressor of FIG. 1;

FIG. 3 is a section view of a muffler assembly;

FIG. 4 is a section view of an alternate muffler assembly;

FIG. 5 is a section view of a compressor; and

FIG. 6 is a schematic illustration of wraps of the compressor of FIG. 1.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present teachings, application, or uses.
The present teachings are suitable for incorporation in many different types of scroll and rotary compressors, including hermetic machines, open drive machines and non-hermetic machines. For exemplary purposes, a compressor assembly 10 is shown including a hermetic scroll refrigerant motor-compressor 12 of the low-side type, i.e., where the motor and compressor are cooled by suction gas in the hermetic shell, as illustrated in the vertical section shown in FIGS. 1, 2, 4 and 5.
As shown in FIGS. 1 and 2, compressor assembly 10 includes compressor 12 and an external muffler assembly 14. Compressor 12 may include a cylindrical hermetic shell 16, a compression mechanism 18, a main bearing housing 20, a motor assembly 22, a refrigerant discharge fitting 24, and a suction gas inlet fitting 26. The hermetic shell 16 may house the compression mechanism 18, main bearing housing 20, and motor assembly 22. Shell 16 may include an end cap 28 at the upper end thereof. The refrigerant discharge fitting 24 is attached to shell 16 at opening 30 in end cap 28. The suction gas inlet fitting 26 is attached to shell 16 at opening 32. The compression mechanism 18 is driven by motor assembly 22 and supported by main bearing housing 20. The main bearing housing 20 may be affixed to shell 16 at a plurality of points in any desirable manner.
The motor assembly 22 generally includes a motor 34, a frame 36 and a crankshaft 38. The motor 34 includes a motor stator 40 and a rotor 42. The motor stator 40 may be press fit into frame 36, which may in turn be press fit into shell 16. Crankshaft 38 is rotatably driven by stator 40. Windings 44 pass through stator 40. Rotor 42 may be press fit on crankshaft 38. A motor protector 46 may be provided in close proximity to windings 44 so that motor protector 46 will de-energize motor 34 if windings 44 exceed their normal temperature range.
Crankshaft 38 may include an eccentric crank pin 48 and one or more counter-weights 50 at an upper end 52. Crankshaft 38 may be rotatably journaled in a first bearing 54 in main bearing housing 20 and in a second bearing 56 in frame 36. Crankshaft 38 may include an oil-pumping concentric bore 58 at a lower end 60. Concentric bore 58 may communicate with a radially outwardly inclined and relatively smaller diameter bore 62 extending to the upper end 52 of crankshaft 38. The lower interior portion of shell 16 is filled with lubricating oil. Concentric bore 58 may provide pump action in conjunction with bore 62 to distribute lubricating fluid to various portions of compressor 12.
Compression mechanism 18 may generally include an orbiting scroll 64 and a non-orbiting scroll 66. Orbiting scroll 64 may include an end plate 68 having a spiral vane or wrap 70 on the upper surface thereof and an annular flat thrust surface 72 on the lower surface. Thrust surface 72 may interface with an annular flat thrust bearing surface 74 on an upper surface of main bearing housing 20. A cylindrical hub 76 may project downwardly from thrust surface 72 and may include a journal bearing 78 having a drive bushing 80 rotatively disposed therein. Drive bushing 80 may include an inner bore in which crank pin 48 is drivingly disposed. Crank pin 48 may have a flat on one surface (not shown) that drivingly engages a flat surface in a portion of the inner bore of drive bushing 80 to provide a radially compliant driving arrangement, such as shown in assignee's U.S. Pat. No. 4,877,382, the disclosure of which is herein incorporated by reference.
Non-orbiting scroll member 66 may include an end plate 82 having a non-orbiting spiral wrap 84 on lower surface 86 thereof. Non-orbiting spiral wrap 84 may form a meshing engagement with wrap 70 of orbiting scroll member 64, thereby creating an inlet pocket 88, intermediate pockets 90, 92, 94, 96, and discharge pocket 98. Non-orbiting scroll 66 may have a centrally disposed discharge passageway 100 in communication with discharge pocket 98 and upwardly open recess 102 which may be in fluid communication with discharge fitting 24. A floating seal 104 may be located around recess 102 and may abut shell 16, thereby providing sealed communication between discharge passageway 100 and discharge fitting 24, while allowing axial displacement of non-orbiting scroll 66 relative to shell 16.
Non-orbiting scroll 66 may be mounted to main bearing housing 20 in any manner that will provide limited axial movement of non-orbiting scroll member 66. For a more detailed description of the non-orbiting scroll suspension system, see assignee's U.S. Pat. No. 5,055,010, the disclosure of which is hereby incorporated herein by reference. Axial pressure biasing may be included in compressor 12, as disclosed in assignee's aforesaid U.S. Pat. No. 4,877,382, A capacity modulation system may also be included in the system, as described in assignee's aforesaid U.S. Pat. No. 6,821,092.
Relative rotation of the scroll members 64, 66 may be prevented by an Oldham coupling, which may generally include a ring 108 having a first pair of keys 110 (one of which is shown) slidably disposed in diametrically opposed slots 112 (one of which is shown) in non-orbiting scroll 66 and a second pair of keys (not shown) slidably disposed in diametrically opposed slots in orbiting scroll 64.
External muffler assembly 14 may include an inlet 114, an outlet 116, and a body portion 118 extending therebetween. A first end 120 of inlet 114 may extend into an inlet opening 122 in body portion 118. A second end 124 of inlet 114 may extend into and be coupled to refrigerant discharge fitting 24.
Outlet 116 may include first and second portions 126, 128 with a connecting portion 130 disposed therebetween. First and second portions 126, 128 may be generally tubular with second portion 128 having a diameter greater than the diameter of first portion 126. Connecting portion 130 may have a radial extent and generally form a stopping member.
A valve seat 132 may be located at an inlet to second portion 128. Valve seat 132 may include apertures 134, 136 for passage of a flow therethrough. Second portion 128, connecting portion 130, and valve seat 132 may define a valve chamber 138. Valve chamber 138 may house a valve member 140 therein.
Valve member 140 may include a disk-shaped body portion 142 having a centrally-disposed aperture 144 therethrough. Valve member 140 may be displaceable from a closed position to an open position by a flow moving in a direction from second portion 128 to first portion 126 and from an open position to a closed position by a flow moving from first portion 126 to second portion 128. When in a closed position, body portion 142 may generally cover apertures 134, 136. When in an open position, valve member 140 may be forced away from apertures 134, 136 and generally toward connecting portion 130.
In the example shown in FIG. 1, body portion 118 is shown including an outlet opening 146 having a diameter generally equal to the diameter of first portion 126 of outlet 116. As such, first portion 126 may extend through outlet opening 146 while second portion 128 and connecting portion 130 may be located within body portion 118.
In FIG. 3, an external muffler assembly 214 is shown generally similar to external muffler assembly 14, with the exception of outlet opening 246 and outlet 216. Specifically, outlet 216 is generally located external to body portion 218, as described below. Outlet opening 246 may have a diameter generally similar to the diameter of second portion 228. As such, second portion 228 is disposed outside of body portion 218. More specifically, valve seat 232 is located in outlet opening 246, resulting in valve chamber 238 and valve member 240 being located outside of body portion 218.
In yet another example, shown in FIG. 4, an external muffler assembly 314 is shown generally similar to external muffler assembly 214. However, external muffler assembly 314 is rotated approximately one hundred and eighty degrees relative to external muffler assembly 214 using U-shaped inlet conduit 414. Rather than being biased to a closed position by gravity as seen in FIG. 3, valve member 340 may be biased to an open position by gravity. Valve member 340 may be forced to a closed position during reverse-flow conditions.
While described in FIGS. 1-4 as having valve member 140, 240, 340 located within outlet 116, 216, valve member 140, 240, 340 may additionally or alternatively be located within body portion 118, 218, generally before second portion 128, 228 of outlet 116, 216. In another arrangement, shown in FIG. 5, a second valve member 248 may be located between external muffler assembly 14, 214 and non-orbiting scroll 66. More specifically, second valve member 248 may be located within recess 102 above discharge passageway 100. Second valve member 248 is shown having plate-like structure 250 and a hinge connection 252. However, any suitable valve assembly may be used, such as one similar to valve member 140. Also, any combination of FIGS. 1-5 may be used.
With reference to FIGS. 1, 3, 4 and 6, the ratio between the volume of muffler assembly 14, 214, 314 more specifically body portion 118, 218, and the intermediate pockets 92, 97 immediately adjacent to discharge pocket 98 before communication between intermediate pockets 92, 97 and discharge pocket 98 may be between 5-to-1 and 20-to-1. Intermediate pockets 92 and 97 may be combined with discharge pocket 98 during a portion of the orbit of orbiting scroll 64 (seen in FIGS. 1, 2 and 5). A ratio between the cross-sectional area of body portion 118, 218 taken generally perpendicular to a flow direction (D) and the cross-sectional area of inlet 114 may generally be greater than or equal to 20-to-1.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.

Claims

1. A compressor assembly comprising:

a shell having an opening therethrough;

a discharge fitting generally extending from said opening in said shell;

a muffler in communication with said discharge fitting and external to said shell, said muffler having an inlet proximate said discharge fitting, an outlet distal from said discharge fitting, and a body portion extending therebetween;

a first valve assembly disposed proximate said outlet of said muffler; and

a compression mechanism disposed within said shell and including a discharge passageway in communication with said opening in said shell for direct discharge of refrigerant from said compression mechanism to said discharge fitting.

2. The compressor assembly of claim 1, wherein said first valve assembly is located within said body portion.

3. The compressor assembly of claim 1, wherein said first valve assembly is contained within said outlet, said outlet having a first portion internal to said body portion and a second portion external to said body portion.

4. The compressor assembly of claim 3, wherein said first valve assembly is located within said second portion of said outlet.

5. The compressor assembly of claim 3, wherein said first valve assembly is located within said first portion of said outlet.

6. The compressor assembly of claim 3, wherein said outlet includes a tubular member secured to said muffler body portion, a valve seat secured to said tubular member, and a valve stop, said valve seat and said valve stop defining a valve chamber, said valve assembly including a valve member disposed within said valve chamber and movable between a closed position where said valve member abuts said valve seat and an open position where said valve member abuts said valve stop.

7. The compressor assembly of claim 1, further comprising a second valve assembly disposed between said discharge passageway and said first valve assembly.

8. The compressor assembly of claim 1, wherein said first valve assembly is configured to move to a closed position when a direction of flow is from said outlet to said inlet, said closed position generally preventing flow from passing from said outlet to said inlet.

9. The compressor assembly of claim 1, wherein said first valve assembly is configured to move to an open position when a direction of flow is from said inlet to said outlet, said open position generally allowing flow to pass from said inlet to said outlet.

10. The compressor assembly of claim 1, wherein said compression mechanism includes first and second scroll members meshingly engaged with one another to form a plurality of intermediate compression pockets and a discharge pocket, a first and second of said intermediate pockets immediately adjacent to said discharge pocket defining a compression volume immediately prior to communication between said first and second intermediate pockets and said discharge pocket, a ratio between a total volume of said muffler and said compression volume being between 5-to-1 and 20-to-1.

11. The compressor assembly of claim 1, wherein a ratio between a cross-sectional area of said muffler taken generally perpendicular to a fluid flow direction therethrough and a cross-sectional area of said inlet being greater than 20-to-1.

12. The compressor assembly of claim 1, wherein said first valve assembly is biased to an open position by gravity.

13. A compressor assembly comprising:

a compressor having a discharge fitting extending therefrom; and

a muffler assembly including a muffler having an inlet, an outlet, and a body portion disposed between said inlet and said outlet, said inlet in communication with said discharge fitting, at least a portion of said inlet being external to said compressor, said outlet having a valve assembly contained therein.

14. The compressor assembly of claim 13, wherein said outlet includes a first portion internal to said body portion and a second portion external to said body portion.

15. The compressor assembly of claim 14, wherein said valve assembly is located within said second portion of said outlet.

16. The compressor assembly of claim 14, wherein said valve assembly is located within said first portion of said outlet.

17. The compressor assembly of claim 14, wherein said outlet includes a tubular member secured to said muffler body portion, a valve seat secured to said tubular member, and a valve stop, said valve seat and said valve stop defining a valve chamber, said valve assembly including a valve member disposed within said valve chamber and movable between a closed position where said valve member abuts said valve seat and an open position where said valve member abuts said valve stop.

18. The compressor assembly of claim 14, wherein said valve assembly is biased to an open position by gravity.

19. A direct discharge compressor muffler comprising:

an inlet;

an outlet;

a body portion disposed between said inlet and said outlet; and

a valve assembly contained within said muffler proximate said outlet, said valve assembly configured to prevent flow from passing in a direction from said inlet to said outlet.

20. The muffler of claim 19, wherein said valve assembly is contained within said outlet.

21. The muffler of claim 20, wherein said outlet includes a first portion internal to said body portion and a second portion external to said body portion.

22. The muffler of claim 21, wherein said valve assembly is located within said second portion of said outlet.

23. The muffler of claim 21, wherein said valve assembly is located within said first portion of said outlet.

24. The muffler of claim 20, wherein said outlet includes a tubular member secured to said muffler body portion, a valve seat secured to said tubular member, and a valve stop, said valve seat and said valve stop defining a valve chamber, said valve assembly including a valve member disposed within said valve chamber and movable between a closed position where said valve member abuts said valve seat and an open position where said valve member abuts said valve stop.

25. The muffler of claim 19, wherein said valve assembly is located within said body portion.

26. The muffler of claim 19, wherein said valve assembly is biased to an open position by gravity.