U.S. patent application number 10/125076 was filed with the patent office on 2003-10-23 for load bearing ribs for fixed scroll.
Invention is credited to Dewar, Todd W., Milliff, Tracy Lanier, Williams, John R..
Application Number | 20030198566 10/125076 |
Document ID | / |
Family ID | 29214719 |
Filed Date | 2003-10-23 |
United States Patent
Application |
20030198566 |
Kind Code |
A1 |
Dewar, Todd W. ; et
al. |
October 23, 2003 |
LOAD BEARING RIBS FOR FIXED SCROLL
Abstract
A scroll compressor includes a non-orbiting scroll having a
plurality of radially extending ribs on its rear face. The
non-orbiting scroll preferably provides a separating function
separating the interior of the sealed housing of the compressor
into the discharge and suction pressure chambers. The ribs extend
from a central portion of the base of the non-orbiting scroll to
its outer peripheral surface. A circumferentially extending rib
also connects the plural radially extending ribs.
Inventors: |
Dewar, Todd W.; (Abingdon,
VA) ; Milliff, Tracy Lanier; (Bristol, VA) ;
Williams, John R.; (Bristol, VA) |
Correspondence
Address: |
CARLSON, GASKEY & OLDS, P.C.
400 WEST MAPLE ROAD
SUITE 350
BIRMINGHAM
MI
48009
US
|
Family ID: |
29214719 |
Appl. No.: |
10/125076 |
Filed: |
April 18, 2002 |
Current U.S.
Class: |
418/55.2 |
Current CPC
Class: |
F04C 18/0253 20130101;
F04C 23/008 20130101 |
Class at
Publication: |
418/55.2 |
International
Class: |
F04C 018/00 |
Claims
What is claimed is:
1. A scroll compressor comprising: a sealed housing; a first scroll
member having a base and a generally spiral wrap extending from
said base, a seal between said base and said housing to define a
discharge pressure chamber on a first side of said base, and a
suction pressure chamber on a second side of said base; a second
scroll member having a base and a generally spiral wrap extending
from said base, said wraps of said first and second scroll members
interfitting to define compression chambers; a motor for driving
said second scroll member to orbit relative to said first scroll
member; and wherein said base of said first scroll member comprises
a center portion and a periphery and wherein plural ribs extend to
about said periphery on said first side.
2. The scroll compressor of claim 1 including a circumferentially
extending rib intersecting said plural ribs.
3. The scroll compressor of claim 2 wherein said circumferentially
extending rib extends at least partially along said periphery and
intersects said plural ribs at said periphery.
4. The scroll compressor of claim 2 wherein said circumferentially
extending rib is at a radially intermediate point, creating
radially outer and radially inner portions of each of said plural
ribs.
5. The scroll compressor of claim 1 wherein said plural ribs extend
radially from said center portion of said base of said first
scroll.
6. The scroll compressor of claim 1 including a boss having a path
to communicate a refrigerant between said compression chambers and
said discharge pressure chamber wherein said plural ribs extend
from said boss to about said periphery.
7. The scroll compressor of claim 1 wherein said plural ribs
extending to about said periphery comprises at least a first rib
and a second rib, said first rib extending along a path transverse
to said second rib.
8. The scroll compressor of claim 8 wherein said first rib extends
along a path generally orthogonal to said second rib.
9. A scroll compressor comprising: a sealed housing; a first scroll
member having a base and a generally spiral wrap extending from
said base, a seal provided between said base and said housing to
define a discharge pressure chamber on a first side of said base,
and a suction pressure chamber on a second side of said base, said
base of said first scroll member comprising a center point; a
second scroll member having a base and a generally spiral wrap
extending from said base, said wraps of said first and second
scroll members interfitting to define compression chambers; a motor
for driving said second scroll member to orbit relative to said
first scroll member; and a plurality of radially extending ribs
extending from a central boss, said central boss communicating said
compression chambers to said discharge chamber, said radially
extending ribs extending from said boss to an outer peripheral
surface on said first side of said base of said first scroll
member, and a circumferentially extending rib connecting said
plural radially extending ribs.
10. The scroll compressor of claim 9 wherein said circumferentially
extending rib extends at least partially along said outer
peripheral surface and intersects said plurality of radially
extending ribs at said outer peripheral surface.
11. The scroll compressor of claim 9 wherein said circumferentially
extending rib is at a radially intermediate point, creating outer
and radially inner portions of each of said plurality of radially
extending ribs.
12. The scroll compressor of claim 9 wherein said circumferentially
extending rib comprises a plurality of ribs at least one rib
extending at least partially along said outer peripheral surface
and another rib spaced between said outer peripheral surface and
said central boss.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a scroll compressor having a
non-orbiting scroll with load bearing ribs.
[0002] Modem refrigerant compressors are often mounted within a
sealed container. In these compressors, the pump unit for
compressing the refrigerant is positioned at one end, and a motor
for driving the pump unit is positioned at another end. Often the
suction pressure refrigerant is allowed to circulate over the
motor, cooling the motor. In such compressors, it becomes necessary
to separate a suction pressure chamber from a discharge pressure
chamber.
[0003] One popular type of modem compressor is a scroll compressor.
A scroll compressor includes a pair of scroll members each having a
base and a generally spiral wrap extending from the base. The wraps
of the two scroll members interfit to define compression chambers.
One of the scroll members is driven to orbit relative to the other,
and during this orbital movement, the compression chambers decrease
in volume.
[0004] In traditional scroll compressors, the non-orbiting scroll
does not seal against the compressor housing. Instead, a separate
separator plate is positioned typically outwardly of the base of
the non-orbiting scroll to separate the housing into the suction
and discharge pressure chambers. Most typically, a discharge
pressure chamber is formed above the separator plate, and the area
below the separator plate is at suction pressure.
[0005] More recently, it has been proposed to incorporate the
separator function into the base of the non-orbiting scroll. In
such compressors, the base of the non-orbiting scroll is sealed to
the housing. Thus, there is the discharge pressure chamber on one
side of the base of the non-orbiting scroll and the suction
pressure chamber on the other.
[0006] In such compressors, compressed refrigerant often reaches
relatively high pressures. With the above discussed recent scroll
compressor improvements, this high pressure may cause the scroll
base to deform toward the suction side of the compressor. This
deformation is undesirable.
[0007] One proposed design employs ribs extending radially from the
center of scroll base across a limited portion of the base. This
design may not offer sufficient support to the base. Moreover, the
design only offers support along a radial path from the base's
center.
[0008] A need therefore exists for a scroll base having greater
support against deflection and deformation.
SUMMARY OF THE INVENTION
[0009] In a disclosed embodiment of this invention, a scroll
compressor has an orbiting scroll member and a non-orbiting scroll
member. The non-orbiting scroll is utilized to separate a housing
containing both scroll members into suction and discharge pressure
chambers. Preferably, the non-orbiting scroll has an outer
peripheral surface sealed to a inner peripheral surface of the
housing defining the suction and discharge pressure chambers. Other
ways of sealing the non-orbiting scroll to the housing may be used.
To limit deflection of the non-orbiting scroll, ribs are formed on
the outer face of the base of the scroll member. The ribs
preferably offer support along a radial and non-radial path from
the center and may extend across the entire scroll member.
[0010] The ribs preferably extend from a center portion of the
non-orbiting scroll member to the periphery of the member. The
extension of ribs to the periphery permits the distribution of load
caused by the pressure differential between the discharge pressure
chamber and the suction pressure chamber across the entire member.
In addition, a rib is preferably formed along the periphery to
provide further support. This peripheral rib intersects the ribs
extending from the center portion. The radially extending ribs meet
in the center portion and connect to a boss of the non-orbiting
scroll member. The non-orbiting scroll member typically has a
circular outer peripheral shape.
[0011] The ribs preferably form a radial design extending from the
center portion of the base. In addition, the invention envisions
the use of ribs so as to distribute loads not only radially but in
a non-radial fashion across the non-orbiting scroll member.
Alternate rib embodiments crisscross and intersect each other to
distribute load across other portions of the non-orbiting scroll
member. Some rib embodiments intersect at perpendicular angles.
[0012] The present invention accordingly permits the non-orbiting
member to be supported by ribbing and avoid deflections and
deformities caused by their absence, thereby providing greater
support to the non-orbiting member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The various features and advantages of this invention will
become apparent to those skilled in the art from the following
detailed description of the currently preferred embodiment. The
drawings that accompany the detailed description can be briefly
described as follows:
[0014] FIG. 1A illustrates a cross sectional view of the invention,
including a scroll member with ribs.
[0015] FIG. 1B shows a prior art scroll member.
[0016] FIG. 2 illustrates the FIG. 1A non-orbiting scroll
member.
[0017] FIG. 3 illustrates another embodiment non-orbiting scroll
member
[0018] FIG. 4 shows another non-orbiting scroll member with radial
ribs.
[0019] FIG. 5 illustrates another non-orbiting scroll member with
non-radial and radial ribs.
[0020] FIG. 6 illustrates a non-orbiting scroll member with ribs, a
waffle pattern rib design.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] A scroll compressor 20 is illustrated in FIG. 1A. As known,
scroll compressor 20 incorporates an orbiting scroll 22 and a
non-orbiting scroll 24. A center shell 26 is secured to an upper
shell 28. A discharge pressure chamber 32 is defined within upper
shell 28, discharging refrigerant through tube 30. Non-orbiting
scroll 24 has abase 100 and a spiral wrap 102 extending from the
base. The orbiting scroll 22 similarly has a base 104 and a spiral
wrap 106. Compression chambers 108 are defined between the two
wraps.
[0022] In the non-orbiting scroll 24, the base is sealed to
periphery 35 of the upper shell 28. The base itself can form a
seal, or a separate seal element can be used. A shaft 36 is driven
by motor 137 to drive the orbiting scroll 22. A suction tube 38
extends through the center shell 26 to supply refrigerant to
chamber 40. As can be seen, suction tube 38 is positioned on a side
of orbiting scroll 22 remote from non-orbiting scroll 24. The
sealing joint between the base of non-orbiting scroll 24 and the
upper shell 28 divides the interior of the housing into the
discharge pressure chamber 32 and the suction pressure chamber
40.
[0023] Boss 42 on base receives a check valve assembly 44, shown
schematically. Refrigerant is compressed between the orbiting and
non-orbiting scrolls 22 and 24 and passes through check valve 44
into chamber 32. Refrigerant in discharge pressure chamber 32 is at
high pressure while suction pressure chamber 40 is at low pressure.
The difference in pressure may cause non-orbiting scroll to deflect
or deform toward suction pressure chamber 40. High temperature of
the non-orbiting scroll may also cause deformation.
[0024] FIG. 1B illustrates a prior art design. Shown is
non-orbiting scroll member 10 with ribs 12 extending from center 14
along a radial direction. As shown in this figure, ribs 12 extend
only across a limited portion of non-orbiting scroll member 10.
Thus, scroll member 10 is supported only across this portion along
a radial path from center 14.
[0025] To increase support, the inventive non-orbiting scroll
member 24 is reinforced by several ribs 50, extending from boss 42
to about periphery 37. Periphery 37 meets wall 33 of upper shell 28
as shown. In this way, ribs 50 provide support against deflection
from boss 42 to periphery 37 across the great majority of member
24. Each rib 50 has first portion 52 extending above land 62 of
base 100 and second portion 54 extending above land 64 of base 100,
reinforcing both areas to prevent deflection of base 100. As shown,
land 64 is elevated relative to land 62 essentially by a
circumferentially extending portion, or rib 180.
[0026] FIG. 2 illustrates the non-orbiting scroll employing the
inventive features of this invention. Boss 42 is located in a
center portion of non-orbiting scroll 24. Boss 42 has passage 74 to
permit the communication of refrigerant between the compression
chamber and the discharge pressure chamber. Non-orbiting scroll 24
comprises base 100, which itself comprises land 62, land 64 and
central portion 82. Land 62 encircles land 64, which encircles boss
42. Moreover, as shown in this figure, land 64 is elevated above
land 62 and shares circumferential rib 180, which provides the
elevated position of land 64 with respect to land 62. Boss 42 may
be elevated above both land 62 and land 64. Supporting base 100
further are radial ribs 50, which may extend from center point 88
to about periphery 37. Periphery 37 is positioned inwardly of outer
periphery 94. Periphery 37 is elevated above outer periphery 94 to
form a circumferential lip 34 which may abut upper shell 28 as
shown in FIG. 1.
[0027] FIG. 3 illustrates another non-orbiting scroll 110 having
base 112, boss 114 and ribs 116 radiating from boss 114. This
particular design also employs rib 118 extending circumferentially
around periphery 120 of base 112. Rib 118 may provide additional
support to base 112 and intersect radial ribs 116. Moreover, rib
118 may form part of the sealing surface for an upper shell of a
sealed housing.
[0028] FIGS. 4, 5 and 6 illustrate other rib patterns. FIG. 4 shows
non-orbiting scroll 126 with base 130 and boss 134. Base 130 is
reinforced by ribs, such as rib 138, extending radially from boss
134 to inner periphery 142. Inner periphery 142 is within outer
periphery 144.
[0029] In addition, base 130 may be reinforced by non-radial ribs
such as rib 156, which extends along a path that does cross center
150. Rib 156 may extend transversely from rib 138, a radial rib.
Rib 158 is also provided, extending circumferentially about inner
periphery 142 and may intersect rib 138 and rib 156. In this way,
the invention provides support radially and non-radially across
base 130, distributing load over, through and around center
150.
[0030] FIG. 5 illustrates another non-orbiting scroll 159 having
center point 160 and ribs 162 and 163 radiating from center point
160. Here, rib 164 is formed that is transverse to ribs 162 and 163
and does not pass through center point 160.
[0031] FIG. 6 illustrates a waffle pattern design, highlighting
again the non-radial rib feature of the invention. Rib 176 extends
across base 174 of non-orbiting scroll 178 along a path that does
not extend through center 170. Another non-radial rib 173 may
intersect rib 176 perpendicularly at point A. One of ordinary skill
in the art can envision other ways to employ both radial and
non-radial ribs to support a non-orbiting scroll to avoid
deformation and its deflection.
[0032] The aforementioned description is exemplary rather that
limiting. 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, one of ordinary skill in the art would recognize that
certain modifications would come within the scope of this
invention. Hence, within the scope of the appended claims, the
invention may be practiced otherwise than as specifically
described. For this reason the following claims should be studied
to determine the true scope and content of this invention.
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