Information
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Patent Grant
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6375444
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Patent Number
6,375,444
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Date Filed
Wednesday, February 14, 200123 years ago
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Date Issued
Tuesday, April 23, 200222 years ago
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Inventors
-
Original Assignees
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Examiners
- Denion; Thomas
- Trieu; Theresa
Agents
-
CPC
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US Classifications
Field of Search
US
- 418 99
- 418 94
- 418 555
- 418 557
- 418 556
- 418 554
- 184 618
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International Classifications
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Abstract
A scroll compressor has a unique oil supply port for supplying lubricant to both the seals and the Oldham coupling. The oil supply port is positioned at a location such that it will not likely result in undue amounts of lubricant being entrained into the refrigerant leading into the compression chambers. The present invention is thus an improvement over the prior art.
Description
BACKGROUND OF THE INVENTION
This invention relates to a unique positioning of an axial oil supply port for a scroll compressor.
Scroll compressors are becoming widely utilized in refrigerant compression applications. In a scroll compressor, a pair of interfitting scroll members each have a base and a generally spiral wrap extending from the base. The wraps interfit to define compression chambers. One of the two scroll members is caused to orbit relative to the other, and the interfitting wraps define compression chambers As the orbiting scroll orbits the size of the compression chambers decrease and an entrapped refrigerant is compressed.
One challenge to a scroll compressor designer is that the entrapped refrigerant creates a force tending to separate the two scroll members. In response to this “separating force” a portion of the refrigerant is tapped from a compression chamber to a back pressure chamber behind the orbiting scroll. This entrapped refrigerant creates a force tending to resist the separating force. A pair of seals are positioned within a crankcase which supports the orbiting scroll to define the back pressure chamber. Further, a coupling is typically positioned radially outwardly of the seals to constrain the orbiting scroll for orbital movement.
It is desirable to supply lubricant both to the seals and to the coupling. In the past, oil is supplied through the driveshaft into a cross-hole extending through the orbiting scroll. This oil is then delivered to a location between the seals and the coupling. In the past this oil has been delivered at a location upstream of the beginning of the orbiting scroll wrap. It is desirable that this oil not be supplied at a location where it is likely to flow into the compression chambers in undue amounts. Thus, it would be desirable to position the cross-hole at a location such that it is unlikely the oil will flow into the scroll compressor.
SUMMARY OF THE INVENTION
In the disclosed embodiment of this invention, a hole for supplying oil to a downwardly extending supply hole is positioned between 25° and 90° from the beginning of the orbiting scroll wrap. More preferably, this hole is positioned 30°.
With this positioning, the lubricant will be adequately supplied, but will not be likely to flow into the compression chambers in any undue amount.
More preferably, the present invention incorporates a scroll compressor wherein there are two refrigerant supply ports spaced by approximately 180°. Thus, the positioning of the supply port downstream of the beginning of the scroll wrap by a limited angular amount will ensure that that oil will not flow in undue amounts into the compression chamber through either of the suction ports. Again, this provides benefits.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a cross-sectional view of a scroll compressor incorporating this invention.
FIG. 2
is a cross-sectional view through the scroll compressor according to this invention.
FIG. 3
is a plan view of the non-orbiting scroll of this invention.
FIG. 4
is a plan view of the orbiting scroll of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
A scroll compressor
20
is illustrated in
FIG. 1
incorporating an orbiting scroll
22
having a generally spiral wrap
23
. The orbiting scroll
22
interfits with a non-orbiting scroll
24
, as known. A radially outer seal
26
and a radially inner seal
28
define a back pressure chamber, as known. An Oldham coupling
30
constrains the orbiting scroll
22
for orbital movement. An input shaft
32
is driven by a motor
36
to rotate. An oil supply passage
34
extends through the shaft
32
, as known. A downwardly extending boss
38
from the orbiting scroll is received on an eccentric pin from the shaft
32
. A passage
40
extends radially outwardly through the base of the orbiting scroll
32
to a downwardly extending port
42
. The port
42
is positioned radially between the outer seal
26
and the coupling
30
.
As shown in
FIG. 2
, the passage
40
extends to the port
42
. A plug
46
closes the passage
40
at its radially outer end to ensure there is adequate pressure to drive sufficient oil through the port
42
.
As shown in
FIG. 3
, the non-orbiting scroll
24
includes a pair of ports
50
and
52
to supply suction refrigerant to the compression chambers. While the present invention is usable with scroll compressors having a single port, it is particularly beneficial for scroll compressors having a pair of ports.
FIG. 4
shows the unique and inventive positioning of the passage
40
relative to the beginning point
54
of the scroll wrap
23
. As shown, an angle B is defined between the end point
54
and the passage
40
. Preferably, that angle B is between 0 and 90°. More preferably, the angle is between 25° and 60°. In a most preferred embodiment the angle is approximately 30°.
With the inventive positioning, the oil supplied to port
32
is at a location such that it is unlikely it will be supplied in undue amounts into either suction port
50
or
52
. Rather, the oil will be supplied at a location such that it will adequately lubricate the couplings
30
and the seals
26
and
28
, and yet will not deliver undue amounts of lubricant into the compression chambers.
In the prior art, the oil supply port was essentially positioned to be in the bottom left hand quadrant of this figure. In such positioning, there is the risk of oil being delivered into the compression chambers, as it will be upstream of the inlet into the compression chambers. This becomes particularly acute in a dual suction port compressor.
Although a preferred embodiment of this invention has been disclosed, a worker in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
Claims
- 1. A scroll compressor comprising:first and second scroll members each having a base and a generally spiral wrap extending from said base; a shaft for causing said second scroll member to orbit, said shaft being driven to rotate by an electric motor; a coupling positioned within said scroll compressor to constrain said second scroll member to orbit; a crankcase supporting said second scroll member, said crankcase having at least one seal for defining a back pressure chamber between an end face of said crankcase and a rear of said base of said second scroll member; and an oil supply passage extending radially outwardly through said base of said second scroll member to an oil supply port extending downwardly through said base toward said crankcase, said oil supply port being positioned radially between said seal and said coupling, and said oil supply passage being positioned in a downstream direction from an outer end of said wrap of said second scroll member by an angle of between 0 and 90°.
- 2. A scroll compressor as recited in claim 1, wherein said angle is between said 25° and 60°.
- 3. A scroll compressor as recited in claim 2, wherein said angle is 30°.
- 4. A scroll compressor as recited in claim 1, wherein said cross-passage is plugged at a radially outer location to ensure sufficient pressure to drive lubricant through said oil supply hole.
- 5. A scroll compressor as recited in claim 1, wherein there are a pair of suction passages leading into compression chambers defined between said first and second scroll members.
- 6. A scroll compressor as recited in claim 5, wherein said suction passages are formed through said first scroll member.
- 7. A scroll compressor comprising:first and second scroll members each having a base and a generally spiral wrap extending from said base, said wraps of said first and second scroll members defining compression chambers, and there being a pair of suction ports extending through said first scroll member for defining said suction ports; a shaft for causing said second scroll member to orbit, said shaft being driven to rotate by an electric motor; a coupling positioned within said scroll compressor to constrain said second scroll member to orbit; a crankcase supporting said second scroll member, said crankcase having at least one seal for defining a back pressure chamber between an end face of said crankcase and a rear of said base of said second scroll member; and an oil supply passage extending radially outwardly through said base of said second scroll member to an oil supply port extending downwardly through said base toward said crankcase, said oil supply port being positioned radially between said seal and said coupling, and said oil supply passage being positioned in a downstream direction from an outer end of said wrap of said second scroll member by an angle of between 25 and 60°.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5989000 |
Tomayko et al. |
Nov 1999 |
A |
6149413 |
Lifson |
Nov 2000 |
A |
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Number |
Date |
Country |
55-160192 |
Dec 1980 |
JP |
61-192881 |
Aug 1986 |
JP |
01-277694 |
Nov 1989 |
JP |
03-145589 |
Jun 1991 |
JP |
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Feb 1992 |
JP |
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