US20080173644A1

US20080173644A1 - Pressure limiter

Info

Publication number: US20080173644A1
Application number: US11/625,494
Authority: US
Inventors: Phillip A. Tomell
Original assignee: Tecumseh Products Co
Current assignee: Tecumseh Products Co
Priority date: 2007-01-22
Filing date: 2007-01-22
Publication date: 2008-07-24
Also published as: CA2618356A1

Abstract

A hermetically sealed compressor including a pressure release device. In one exemplary embodiment, the pressure release device includes a flange portion and a rupture portion. The flange portion is positioned against and secured to the inner surface of the housing of a hermetically sealed compressor. In this embodiment, the rupture portion extends at least partially within a vent aperture extending through the compressor housing. When the interior pressure of the housing exceeds a predetermined limit, the rupture portion of the pressure release device opens allowing the fluid within the compressor housing to escape. In another exemplary embodiment, the pressure release device further includes a connecting portion positioned between the flange portion and the rupture portion. In one exemplary embodiment, the connecting portion forms an S-curve.

Description

BACKGROUND

1. Field of the Invention.
The present invention relates to a pressure release device, particularly to a pressure release device for use with hermetically sealed compressors.
2. Description of the Related Art.
During operation of a hermetically sealed compressor, fluid, such as refrigerant, is compressed by a compressor mechanism positioned within a housing. In a “high side” compressor, the fluid is discharged into the housing, increasing the pressure therein to equal the discharge pressure of the fluid. To ensure effective operation of the compressor in adverse conditions, the housing of a hermetically sealed compressor is designed to withstand internal pressures substantially greater than the discharge pressure of the fluid. However, when a fan is blocked or when a substance having a lower boiling point than the fluid, such as water, is introduced into the system, the pressure within the housing may rise to a pressure exceeding the upper pressure limit of the housing.
To allow for the release of excess pressure from the hermetically sealed compressor, some prior compressor housings may be coined, i.e., stamped, to weaken a portion of the compressor housing. The process of coining the compressor housing is not exact enough to avoid venting at too low or too high of an excess pressure. Additionally, due to the varying sizes, compositions, and thicknesses of different compressor housings, the coining process itself must be modified for each individual housing.

SUMMARY OF THE INVENTION

The present invention relates to a pressure release device, particularly to a pressure release device for use with a hermetically sealed compressor. In one exemplary embodiment, the pressure release device includes a flange portion and a rupture portion. The flange portion is positioned against and secured to the inner surface of the housing of a hermetically sealed compressor. In this embodiment, the rupture portion extends at least partially within a vent aperture extending through the compressor housing. When the interior pressure of the housing exceeds a predetermined limit, the rupture portion of the pressure release device opens allowing the fluid within the compressor housing to escape. In another exemplary embodiment, the pressure release device further includes a connecting portion positioned between the flange portion and the rupture portion. In one exemplary embodiment, the connecting portion forms an S-curve.
Advantageously, the present pressure release device provides for the release of fluid at a predetermined pressure irrespective of the thickness of the compressor housing. Thus, the pressure release device can be used interchangeably with compressors having varying housing thicknesses. This eliminates the need to modify the size or shape of the pressure release device for different compressor housings. Additionally, the flange of the pressure release device is positioned adjacent the interior of the compressor housing, which, due to the pressure within the housing, forces the flange against the inner surface of the housing. In the event the rupture portion of the pressure release device opens, the interaction between the flange of the pressure release device and the inner surface of the housing secures the pressure release device to the housing. Moreover, by positioning the pressure release device over and/or in an aperture in the compressor housing, the pressure release device cannot be bypassed by the user. Thus, once the rupture portion of the pressure release device has opened, allowing the release of fluid from the compressor housing, the pressure release device cannot be closed and the compressor housing must be replaced.
In one exemplary embodiment, the present pressure release device is positioned on a sidewall of the compressor housing opposite the electric terminal cluster. Advantageously, this allows the excess pressure to be released to a single side of the compressor typically away from someone servicing the compressor. In contrast, prior art devices would often release excess pressure either upward or downward. When released upward, the excess pressure would force working fluid upward, toward any person standing at or near the compressor. Alternatively, when released downward, the excess pressure would force working fluid into a support or base upon which the compressor was mounted, causing the working fluid to be deflected in any or all directions. Additionally, in another exemplary embodiment, the pressure release device is configured to be attached to a flattened portion of the compressor housing. This allows the pressure release device to evenly distribute pressure encountered during operation of the compressor and prevents expansion and contraction of the compressor housing from impairing the function of the pressure release device.
In one form thereof, the present invention provides a hermetically sealed compressor, including a housing having an outer surface and an inner surface, the inner surface substantially defining a hermetically sealed chamber; a motor and compressor unit driven thereby supported within the housing; a vent aperture extending between the outer surface of the housing and the inner surface of the housing; and a pressure release device having a flange portion and a rupture portion, the flange portion positioned against and secured to the inner surface of the housing, the rupture portion extending at least partially across the vent aperture, whereby excessive pressure of the fluid within the housing causes the rupture portion to open.
In another form thereof, the present invention provides a hermetically sealed compressor, including a housing having an outer surface and an inner surface, the inner surface substantially defining a hermetically sealed chamber; a motor and compressor unit driven thereby supported within the housing; a vent aperture formed in a sidewall of the housing and extending between the outer surface and the inner surface; a multi-pin terminal cluster positioned substantially opposite the vent aperture; and a pressure release device having a flange portion and a rupture portion, the flange portion positioned against and secured to the inner surface of the housing, the rupture portion extending at least partially across the vent aperture, whereby excessive pressure within the housing causes the rupture portion to open.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a sectional view of a compressor including a pressure relief device in accordance with one form of the present invention;

FIG. 2 is a plan view of the lower housing portion of the compressor of FIG. 1 wherein the compressor mechanism has been removed;

FIG. 3 is a sectional view of the lower housing portion taken along line 3-3 of FIG. 2 and viewed in the direction of the arrows;

FIG. 4 is a side view of the lower housing portion partially cutaway to expose the pressure release device of the present application;

FIG. 5 is an enlarged fragmentary cross sectional view of the lower housing portion taken along line 5-5 of FIG. 4 and viewed in the direction of the arrows;

FIG. 6 is a rear view of the pressure release device of FIG. 4;

FIG. 7 is a cross sectional view of the pressure release device taken along line 7-7 of FIG. 6 and viewed in the direction of the arrows;

FIG. 8 is a front view of the pressure release device of FIG. 7 viewed along line 8-8 of FIG. 7 in the direction of the arrows; and

FIG. 9 is an enlarged fragmentary cross sectional view of the pressure release device of FIG. 7.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

Referring to FIG. 1, hermetically sealed compressor housing 10 includes lower housing portion 12 and upper housing portion 14. Compressor mechanism 16 is positioned within compressor housing 10 and includes motor 18 having stator 20 and rotor 22, which drive crankshaft 24 in a known manner. Compressor mechanism 16 is depicted as a radial piston compressor having piston 26 positioned within cylinder 28. Piston 26 reciprocates within cylinder 28 via connecting rod 30 and eccentric 32 in a known manner. While compressor mechanism 16 is depicted and described herein as a radial piston compressor, any known compressor mechanism, e.g., a scroll or rotary compressor, may be utilized. When compressor mechanism 16 is in operation, fluid is compressed from a low, suction pressure to a higher, discharge pressure. The fluid is then discharged into plenum 34 of compressor housing 10, increasing the pressure therein until it reaches the discharge pressure. In the event of a compressor malfunction, e.g., a blocked fan, the pressure within compressor housing 10 will begin to rise above the discharge pressure. To prevent the pressure from reaching a point sufficient to cause the hermetically sealed housing 10 to burst or otherwise fail, pressure release device 36 is utilized.
As shown in FIGS. 6-8, pressure release device 36 includes rupture portion 38, connecting portion 40, and flange portion 42. Rupture portion 38 includes groove 44 (FIGS. 8 and 9) formed therein to weaken rupture portion 38 and facilitate the opening of rupture portion 38 upon plenum 34 reaching a predetermined pressure limit. When rupture portion 38 of pressure release device 36 opens, at least a portion of rupture portion 38 separates from pressure release device 36 to release the pressure within plenum 34 of compressor 10 into the outside environment in a controlled manner. Once pressure release device 36 has opened, compressor mechanism 16 can no longer be functionally utilized, as the compressed fluid will exit compressor housing 10 via open rupture portion 38 of pressure release device 36.
As shown in FIG. 9, by increasing or decreasing depth D of groove 44 relative to bottom surface 46 of pressure release device 36, the predetermined pressure limit of pressure release device 36 is altered. In another embodiment, the predetermined pressure limit of pressure release device 36 is altered by increasing width W of groove 44. By altering the predetermined pressure limit of pressure release device 36, pressure release devices responsive to different pressure limits can be created for different compressors. This eliminates the need to significantly alter the design of pressure release device 36 or compressor housing 10. Additionally, while described and depicted herein as continuous, groove 44 may also be discontinuous and may, in one exemplary embodiment, include a plurality of grooves 44.
As shown in FIGS. 2 and 3, lower housing portion 12 includes inner surface 48 and outer surface 50. Corresponding pairs of mounting ears 52 (FIG. 2) are attached to base 54 (FIG. 3) of lower housing portion 12. Mounting ears 52 facilitate the attachment of compressor housing 10 to bases, stands, or other mounting components. Additionally, as shown in FIG. 2, lower housing portion 12 includes multi-pin terminal cluster 56 extending therethrough for conveying electric power to motor 18 of compressor mechanism 16.
Lower housing portion 12 further includes vent aperture 58 extending therethrough for partial receipt of pressure release device 36 therein. Vent aperture 58 is in fluid communication with the interior of housing 10 and the outside environment. Vent aperture 58 and pressure release device 36 are oriented between pairs of mounting ears 52 and are substantially opposite multi-pin terminal cluster 56. Generally, a technician or other maintenance personnel will be working near multi-pin terminal cluster 56 and the refrigerant inlet/outlet (not shown) during the servicing or repair of compressor mechanism 16. By placing vent aperture 58 and pressure release device 36 substantially opposite multi-pin terminal cluster 56 and the refrigerant inlet/outlet, the likelihood of a technician or other maintenance personnel being near vent aperture 58 and pressure release device 36 during a release of compressed fluid is lessened. Further, vent aperture 58 is formed in sidewall 60 of lower housing portion 12. Advantageously, forming vent aperture 58 in sidewall 60 allows for the release of fluid from hermetically sealed compressor housing 10 without any deflection of the fluid. In contrast, forming vent aperture 58 in base 54 of lower housing portion 12 results in uncontrolled deflection of fluid by a supporting surface in the event of the release of compressed fluid therethrough.
In one exemplary embodiment, to facilitate attachment of pressure release device 36 to lower housing portion 12, a portion of sidewall 60 is flattened. Flattening sidewall 60 of lower housing portion 12 around vent aperture 58 allows for the attachment of pressure release device thereto with any need to modify or bend pressure release device 36. Additionally, this design helps to ensure that the pressure encountered by pressure release device 36 will be distributed uniformly therealong. In one exemplary embodiment, sidewall 60 of lower housing portion 12 is flattened in conjunction with the creation of vent aperture 58 therein. In another exemplary embodiment, sidewall 60 remains curved and an annular ring (not shown) having a first curved surface matching the curvature of sidewall 60 and a second, opposing flat surface is utilized. The annular ring is positioned with the curved surface around vent aperture 58 and against inner surface 48 of lower housing portion 12 defining sidewall 60, eliminating the need to flatten sidewall 60. In this position, the annular ring is secured in place and pressure release device 36 is coupled within housing 10 to the opposing, flat surface of the annular ring.
Referring to FIGS. 5-8, flange portion 42 is welded to inner surface 48 of lower housing portion 12 to facilitate securement of pressure release device 36 thereto. Connecting portion 40 is positioned between and connects rupture portion 38 to flange portion 42. In one exemplary embodiment shown in FIG. 5, connecting portion 40 includes S-shaped curve 62. As pressure builds within housing 10, upper and lower housing portions 12, 14 undergo deformation in response thereto. S-shaped curve 62 helps prevent deformation of pressure release device 36 resulting from the deformation of housing 10 by raising pressure release device 36 from inner surface 48 of lower housing portion 12. This helps ensure the accuracy of pressure release device 36. In addition, the use of S-shaped curve 62 of connecting portion 40 prevents any sharp or otherwise irregular portion of sidewall 60 of lower compressor housing 12 defining vent aperture 48 from damaging pressure release device 36 and potentially altering the predetermined pressure limit of pressure release device 36.
As discussed above, pressure release device 36 is positioned with rupture portion 38 extending at least partially within vent aperture 48 and flange portion 42 positioned against inner surface 48. Thus, in the event the connection between flange portion 42 and sidewall 60 of inner surface 48 of lower housing portion 12 fails, pressure release device 36 will remain in position due to the internal pressure of hermetically sealed compressor housing 10 forcing flange 42 against inner surface 48. In one exemplary embodiment, pressure release device 36 is comprised of tin plated 1010 carbon steel. However, other materials capable of withstanding the necessary pressures may also be utilized.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

Claims

1. A hermetically sealed compressor, comprising:

a housing having an outer surface and an inner surface, said inner surface substantially defining a hermetically sealed chamber;

a motor and compressor unit driven thereby supported within said housing;

a vent aperture extending between said outer surface of said housing and said inner surface of said housing; and

a pressure release device having a flange portion and a rupture portion, said flange portion positioned against and secured to said inner surface of said housing, said rupture portion extending at least partially across said vent aperture, whereby excessive pressure of the fluid within said housing causes said rupture portion to open.

2. The hermetically sealed compressor of claim 1, wherein said rupture portion extends at least partially within said vent aperture.

3. The hermetically sealed compressor of claim 1, wherein said rupture portion includes a connecting portion between said flange portion and said rupture portion, said connecting portion forming an S-curve.

4. The hermetically sealed compressor of claim 1, wherein said flange portion of said pressure release device is secured to said inner surface of said housing by welding.

5. The hermetically sealed compressor of claim 1, further comprising a multi-pin terminal cluster, said multi-pin terminal cluster positioned substantially opposite said pressure release device.

6. The hermetically sealed compressor of claim 1, wherein said pressure release device is formed of tin plated carbon steel.

7. The hermetically sealed compressor of claim 1, wherein said vent aperture is in fluid communication with the environment.

8. The hermetically sealed compressor of claim 1, wherein said pressure release device is formed as a disk.

9. The hermetically sealed compressor of claim 1, wherein said rupture portion of said pressure release device is substantially defined by a groove.

10. The hermetically sealed compressor of claim 1, wherein a portion of said housing surrounding said vent aperture is flattened.

11. A hermetically sealed compressor, comprising:

a motor and compressor unit driven thereby supported within said housing;

a vent aperture formed in a first sidewall of said housing and extending between said outer surface and said inner surface of said housing;

a multi-pin terminal cluster positioned on a second sidewall of said housing substantially opposite said vent aperture; and

a pressure release device having a flange portion and a rupture portion, said flange portion positioned against and secured to said inner surface of said housing, said rupture portion extending at least partially across said vent aperture, whereby excessive pressure of the fluid within said housing causes said rupture portion to open and release the excessive pressure through the first sidewall of the housing.

12. The hermetically sealed compressor of claim 11, wherein said rupture portion extends at least partially within said vent aperture.

13. The hermetically sealed compressor of claim 11, wherein said rupture portion includes a connecting portion between said flange portion and said rupture portion, said connecting portion forming an S-curve.

14. The hermetically sealed compressor of claim 11, wherein said flange portion of said pressure release device is secured to said inner surface of said housing by welding.

15. The hermetically sealed compressor of claim 11, wherein said second sidewall is adjacent said first sidewall.

16. The hermetically sealed compressor of claim 11, wherein a portion of said housing surrounding said vent aperture is flattened.

17. The hermetically sealed compressor of claim 11, wherein said pressure release device is formed as a disk.