Information
-
Patent Grant
-
6592344
-
Patent Number
6,592,344
-
Date Filed
Thursday, November 29, 200122 years ago
-
Date Issued
Tuesday, July 15, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 418 551
- 418 83
- 029 888022
- 417 310
-
International Classifications
-
Abstract
The present invention is for the retention of a heat shield for a scroll compressor. In one embodiment, the heat shield is deformed into a position such that it rests in a groove located in the non-orbiting scroll. In another embodiment the housing end cap deforms the heat shield. The deformed position of the heat shield prevents flexing and vibrating found in heat shields of prior art. In addition the heat shield must have holes in it to allow for the discharge valve to pass through. The present invention is to put slots in the heat shield, thus preventing the need for exact alignment of the heat shield in position.
Description
BACKGROUND OF THE INVENTION
The present invention relates to the retention of a heat shield in a sealed scroll compressor by creating a bias force on the heat shield.
Modern refrigerant compressors are typically contained within a sealed shell. The compressors are frequently divided into two compartments, a discharge chamber and a suction chamber.
A scroll compressor is one common type of sealed compressor. In a scroll compressor an orbiting scroll and a non-orbiting scroll each have a base, with generally spiral wraps extending from the bases. The orbiting scroll and the non-orbiting scroll are placed together such that the wraps create compression chambers. A shaft connected to a motor drives the orbiting scroll. As the orbiting scroll orbits the volume of the compression chambers is decreased.
Refrigerant is compressed in the chambers and discharged into the discharge chamber through a discharge port located in the non-orbiting scroll. The refrigerant may reach high temperature within the discharge chamber.
Historically, a thick separator plate isolated the discharge chamber from the base of the non-orbiting scroll. More recently, scroll compressor designs have attempted to eliminate the separator plate.
However, without a separator plate the refrigerant in the discharge chamber comes into contact with the base of the non-orbiting scroll. The refrigerant heats the base and consequently the compression chambers, which costs efficiency. A relatively thin heat shield has been placed extending about the base of the non-orbiting scroll. Due to the operation of the scroll compressor, there are pressure and temperature differences on each side of the heat shield. The pressure and temperature differences may create vibration and flexing of the thin heat shield.
One other concern is the heat shield may need to have openings, such as to allow flow from a pressure relief valve. In the past this has required that the heat shield be precisely aligned within the compressor such that the opening in the heat shield is aligned over the pressure relief valve to facilitate flow.
SUMMARY OF THE INVENTION
In embodiments of this invention a heat shield is associated within the base of a non-orbiting scroll. As known, the heat shield provides a barrier to insulate the non-orbiting scroll from the hot refrigerant in the discharge chamber. To address the above mentioned concern the heat shield is held at a deformed position such that a bias force resists flexing or vibration.
In a preferred embodiment a groove is placed in a boss surrounding a discharge port in the non-orbiting scroll. The heat shield is deformed into the groove. In a free state, the heat shield has a disc like appearance. An opening in the center of the heat shield is received over the boss. The heat shield is placed on the boss and pressed down. Essentially there is an interference fit between the heat shield and the boss. This fit deforms the heat shield away from its free curved shape creating a spring pre-load. The bias force from the deformation keeps the heat shield in position resisting flexing or vibration.
Preferably the inner edge of the heat shield is held in position in a groove located in the boss. The groove may have several different configurations. In the preferred configuration the bottom side of the groove is flat with a radius at the corner. The edge extends upward and is angled slightly toward the outside of the scroll. The angle prevents the heat shield from moving out of the groove.
In another embodiment the groove can be square cut. This groove has a distinct bottom, side, and top portion. This groove provides good support from the top when holding the heat shield in place. A third embodiment includes an angled groove, which has only two sides. The bottom side of the groove is flat, and a side extends upwardly and outwardly.
An alternative to having a curved heat shield is an embodiment where the outside edge of the heat shield is turned upward. The outside edge contacts the upper end cap when installed, deforming the heat shield when the end cap is secured to the compressor housing. This contact creates a downward bias force on the heat shield. Again, the bias force resists flexing and vibrating of the heat shield following installation.
In another embodiment, the heat shield is captured between the non-orbiting scroll and the outer housing. A portion of the heat shield is deformed when held at this captured position such that the bias force as mentioned above does occur.
One other aspect of the invention provides a heat shield, which more easily accommodates components such as a pressure relief valve. The valve requires a hole to be placed in the heat shield allowing the flow to pass through. One known heat shield is used with a non-orbiting scroll having ribs on a rear face, with pockets between the ribs. There is usually a hole in the heat shield through which the flow from the pressure relief valve may pass. However the single hole has needed to be aligned over the pressure relief valve. This aspect of the invention allows for the adjustments to be made in the alignment of the heat shield and the relief valve. In one aspect the hole aligned over the pressure relief valve can be a slot to allow for the valve and the heat shield to be slightly misaligned and still allow flow through the hole. There may also be a plurality of holes within an area of the heat shield, or a series of spaced holes in the heat shield. The holes may be off center within the heat shield again to allow for misalignment.
These and other features of the present invention can be best understood from the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings describe the invention in an illustrative manner, by way of example only:
FIG. 1
shows a prior art scroll compressor
FIG. 2
shows a side view of a heat shield according to the present invention prior to installation
FIG. 3A
is a top view of a heat shield according to the present invention
FIG. 3B
is a side view of heat shield according to the present invention
FIG. 4
is a side view of heat shield following installation on the scroll compressor
FIG. 5
shows a cross-section of the non-orbiting scroll boss showing location of the heat shield groove.
FIG. 6
is a side view of the preferred embodiment of the heat shield groove
FIG. 7
shows a side view of an alternative embodiment of the heat shield groove
FIG. 8
is a side view of a third embodiment of the heat shield groove
FIG. 9
is a side view of an alternate embodiment of the invention, after installation on the scroll compressor
FIG. 10A
shows a cross-sectional view of another embodiment.
FIG. 10B
shows an undeformed portion of the
FIG. 10A
embodiment.
FIG. 11
is a top view of the non-orbiting scroll.
FIG. 12
is a top view of another embodiment heat shield.
FIG. 13
shows a top view of another embodiment heat shield.
FIG. 14
shows a top view of another embodiment heat shield.
FIG. 15
shows a top view of yet another embodiment heat shield.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A known scroll compressor
21
includes a heat shield
22
, as shown in FIG.
1
. Scroll compressor
21
includes an orbiting scroll
23
and a non-orbiting scroll
24
. Non-orbiting scroll
24
has a base
25
, with generally spiral wraps
26
extending from the base. Likewise orbiting scroll
23
has a base
27
with generally spiral wraps
28
. The orbiting scroll
23
and the non-orbiting scroll
24
are placed together and the wraps
26
and
28
create compression chambers
29
. A shaft
30
connected to a motor drives orbiting scroll
23
, and as this occurs the volume of the compression chambers
29
is decreased.
The non-orbiting scroll
24
is sealed to the outer housing end cap
31
of the compressor
21
in the area of
32
, thus creating two separate chambers, a discharge chamber
33
and a suction chamber
34
. Suction pressure refrigerant passes through suction tube
35
and enters chamber
34
. Thus, the non-orbiting scroll
24
provides the function of a separator plate. Refrigerant is compressed in chambers
29
and discharged into discharge chamber
33
through a discharge port
36
located in the non-orbiting scroll
24
.
The refrigerant in discharge chamber
33
is at a relatively high temperature. A heat shield
22
is used to insulate the base of the non-orbiting scroll
24
from the heat of the discharge chamber
33
. This in turn insulates the refrigerant in the compression chambers
29
from the heat. The heat shield
22
is a relatively thin component extending about the base
25
of the non-orbiting scroll
24
with chambers
37
and
38
between the base
25
and the heat shield
22
.
A pressure difference often exists across the heat shield
22
due to the variance in pressure and temperature on each side of the heat shield
22
. A pressure relief valve
39
may extend from non-orbiting scroll
24
. Also the discharge of refrigerant into chamber
33
is somewhat cyclic and causes cyclic pressure variation in chamber
33
. As a result of the pressure differences the heat shield
22
may vibrate or flex in its position, thus creating noise. The compressor described to this point is generally as disclosed in U.S. patent application entitled “Scroll Compressor with Heat Shield” (U.S. Pat. No. 6,287,089)
To address the above noise the heat shield of this invention is deformed so as to be biased into either the base
25
, or an end cap
31
. As shown in
FIG. 2
, groove
40
is formed in a boss
41
in non-orbiting scroll
24
to receive an inner end
42
of heat shield
43
. As explained below, the heat shield
43
is held at this position with a bias force.
In the preferred embodiment of the invention the heat shield
43
has a free shape with a disc like appearance, as shown FIG.
3
A. As can be seen there is a cut out area
44
in the center of the heat shield
43
along inner end
42
. The curved shape of the disk is shown in
FIG. 3B
as having an upwardly extending curved shape
45
.
Opening
44
allows heat shield
43
to fit over a boss
41
extending from the top of the fixed scroll
24
, as shown in FIG.
2
. Once the heat shield
43
had been placed on boss
41
it is pressed down. The curved shape
45
of the heat shield
43
, as shown in
FIG. 3B
, is forced downwardly with groove
40
providing an interference fit. When the shield is forced to its operative position, as shown in
FIG. 4
, a spring bias is created trying to move the heat shield back to the
FIG. 2
position.
The preferred location of the groove
40
in the boss
41
is shown in FIG.
5
.
FIG. 6
shows the preferred shape of the groove
40
. The groove
40
may have several different configurations. The bottom side
50
of the groove
40
is flat with a radius
51
at the corner. The edge extending upward
52
is angled slightly toward the outside of the scroll. The angle prevents the heat shield from moving out of the groove
40
.
In another embodiment the groove
40
can be square cut, shown in FIG.
7
. This groove has a distinct bottom
60
, side
61
, and top portion
62
. This more distinct groove provides good support from the top when holding the heat shield
43
in place.
As shown in
FIG. 8
, a third embodiment shows an angled groove, which has only two sides. The bottom side
70
of the groove being flat, and a side
71
extending upward and outward from that.
FIG. 9
shows another embodiment where the outside edge
80
of a heat shield
81
is turned upward. An upper end cap
31
contacts the outward edge
80
at
82
. This contact creates a downward bias force on the heat shield
81
. Once the upper end cap
31
is welded to center shell
83
the heat shield
81
is deformed by this contact. Again this creates a bias force resisting flexing and vibrating of the heat shield.
As shown in
FIG. 10A
, a non-orbiting scroll
24
and an outer housing end cap
31
capture a shoulder portion
88
of a heat shield
90
. Such a heat shield is better described in U.S. Pat. No. 6,428,293, the capturing aspect of which is incorporated herein by reference.
The heat shield
90
as disclosed in this invention preferably has a contact point
92
contacting a portion of the non-orbiting scroll
24
. This contact point leads to some deformation in the heat shield
90
, such that the benefits mentioned above are achieved.
As shown in
FIG. 10B
, the heat shield
90
has an undeformed shape
94
which is deformed to the position
96
such as shown in phantom in
10
B when the heat shield is captured between the non-orbiting scroll
24
and the end cap
31
. When held in this position, a bias force tending to bias the heat shield back against the non-orbiting scroll is created, providing the benefits as mentioned above.
The portion
94
may be one, or a plurality of circumferentially spaced portions which are deformed to the phantom position shown in
96
, or could be a circumferentially continuous portion.
There is also a requirement for the heat shield
43
to allow passage of flow from pressure relief valve
39
. As can be seen from non-orbiting scroll shown in
FIG. 11
there may be ribs
92
and pockets
91
around pressure relief valve
39
. Likewise the heat shield
43
has ribs
92
running across it, between the ribs
92
there are pockets
93
. In order to fit, the heat shield
43
requires a hole
94
in one of its pockets
93
allowing the flow from the pressure relief valve
39
to pass through. In another aspect of this invention, the holes
94
have been modified in order to accommodate for misalignment of the heat shield
43
and the pressure relief valve
39
.
FIG. 12
shows an embodiment of this with one hole
94
within each pocket
93
of the heat shield. With this feature, the heat shield does not require being particularly aligned with the non-orbiting scroll.
In another embodiment there may be a plurality of holes in a pocket
93
, as shown in
FIGS. 13 and 14
. These holes
94
may be aligned so they are off center. Another embodiment shows that there may be holes in more than one of the ribs
92
.
In
FIG. 13
the holes
94
in the heat shield
143
are set off center within the pocket, allowing for a valve
39
that has been set off center to still be aligned to facilitate flow of gasses to pass through the holes
94
. Furthermore the valve
39
may not be located the same distance from the center in every heat shield.
FIG. 14
shows an embodiment
243
in which the holes
194
vary in distance from the center of the heat shield.
FIG. 15
shows another variation
343
for allowing misalignment of a flow valve
39
and the required hole in the heat shield
43
is to replace the holes with slots
95
.
The foregoing description is only exemplary of the principles of the invention. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, so that one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention
Claims
- 1. A scroll compressor assembly comprising;a sealed housing including a center shell and an upper end cap; a non-orbiting scroll having a base, and a generally spiral wrap extending from said base; an orbiting scroll, having a base and generally spiral wrap extending from its base to fit within said spiral wrap of non-orbiting scroll; a motor to drive said orbiting scroll; a discharge chamber formed within said sealed housing on one side of non-orbiting scroll; a suction chamber formed within sealed housing on a second side of orbiting and non-orbiting scroll assembly; said non-orbiting scroll having an outer peripheral surface sealed to an inner peripheral surface of said housing such that said non-orbiting scroll provides a separation between said suction chamber and said discharge chamber; and a heat shield between said upper end cap and said base of said non-orbiting scroll, said heat shield being deformed away from a free position to create a bias force holding said heat shield, said heat shield being exposed to discharge pressure refrigerant from said discharge chamber on a side of the heat shield removed from said non-orbiting scroll.
- 2. The compressor of claim 1 wherein an outer edge of said heat shield is turned upwardly, said upper end cap creating a bias force on said outward edge.
- 3. The compressor of claim 1 wherein a boss extends from said non-orbiting scroll into said discharge chamber, said heat shield having a hole in the center to fit over and attach to said boss of said non-orbiting scroll.
- 4. The compressor of claim 3 including at least one groove in said non-orbiting scroll boss for affixing said heat shield in position.
- 5. The compressor as described in claim 4 wherein said at least one groove are square-cut.
- 6. The compressor as described in claim 4 wherein said at least one groove are angled grooves.
- 7. The compressor as described in claim 4 where said at least one groove have a radial corner.
- 8. The compressor of claim 1 where said heat shield contains ribs such that there are pockets between said ribs, and a hole in said heat shield allowing multiple positions for the heat shield to be installed and still allows said pressure relief valve to pass through said hole.
- 9. The compressor of claim 8 wherein said hole is a slot.
- 10. The compressor of claim 8 wherein there is at least one said hole in each pocket.
- 11. The compressor of claim 8 wherein there are at least two said holes in at least one pocket.
- 12. The compressor of claim 11 wherein at least one of said holes is off-center.
- 13. The compressor of claim 1, wherein the heat shield is captured between said non-orbiting scroll and said upper end cap, and a portion of the heat shield is deformed against said non-orbiting scroll to create said bias force.
- 14. The compressor of claim 13 wherein said heat shield contains a hole in center allowing passage of a boss extending from said non-orbiting scroll, said boss containing at least one groove for affixing said heat shield in position.
- 15. A scroll compressor comprising;a sealed housing including a center shell and an upper end cap, a non-orbiting scroll having a base and a generally spiral wrap extending from said base; an orbiting scroll having a base and a generally spiral wrap extending from its base to fit within said spiral wrap of non-orbiting scroll; a motor to drive said orbiting scroll; a discharge chamber formed within sealed housing on other side of orbiting and non-orbiting scroll assembly; a pressure relief valve extending from said base of non-orbiting scroll into said discharge chamber; a heat shield between said upper end cap and said base of non-orbiting scroll said base containing ribs such that there are pockets between said ribs, said heat shield being deformed away from a free position to create a bias force holding said heat shield, said non-orbiting scroll having an outer peripheral surface sealed to an inner peripheral surface of said housing such that said non-orbiting scroll provides a separation between said suction chamber and said discharge chamber; and a hole in said heat shield such that it allows multiple positions for the heat shield to be installed and still allows said pressure relief valve to pass through said hole, said heat shield being exposed to discharge pressure refrigerant from said discharge chamber on a side of the heat shield removed from said non-orbiting scroll.
- 16. The compressor of claim 15 wherein said hole is a slot.
- 17. The compressor of claim 15 wherein said hole is off-center within said pocket.
- 18. The compressor of claim 15 wherein there is at least two holes associate with a pocket.
- 19. The compressor of claim 15 wherein there is at least one hole in every pocket.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4904165 |
Fraser et al. |
Feb 1990 |
A |
5487654 |
Wallis et al. |
Jan 1996 |
A |