Information
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Patent Grant
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6443719
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Patent Number
6,443,719
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Date Filed
Tuesday, February 20, 200123 years ago
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Date Issued
Tuesday, September 3, 200222 years ago
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Inventors
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Original Assignees
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Examiners
- Denion; Thomas
- Trieu; Theresa
Agents
-
CPC
-
US Classifications
Field of Search
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International Classifications
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Abstract
An improved Oldham coupling ring is relatively easy to manufacture. Opposed circular arc portions are connected by angled portions to opposed flat portions. The circular arc portions are centered on a common center. As such, the invention is relatively easy to manufacture when compared to prior art systems.
Description
BACKGROUND OF THE INVENTION
This invention relates to an Oldham coupling which is manufactured in a simplified manner.
Scroll compressors are becoming widely utilized in refrigerant compression applications. In a typical scroll compressor a first scroll member has a base and a generally spiral wrap extending from the base. The wrap of the first scroll member interfits with a spiral wrap of a second scroll member, and the scroll member is driven to orbit relative to the first scroll member to compress an entrapped refrigerant. The orbiting movement is achieved from a rotary motor which is connected to the second scroll member through a non-rotation coupling. Typically, an Oldham coupling is provided. The Oldham coupling includes keys which slide in slot structures on the second scroll member, and which in turn has keys extending into slots in a crankcase which supports the second scroll member. In some Oldham couplings, the first scroll member receives the keys rather than the crankcase. The Oldham coupling can move in the slots in the crankcase along a linear path. This allows rotation of the drive motor to be translated into orbiting movement of the second scroll member.
The Oldham coupling is a relatively simple part, but it must meet several design criteria. In particular, the Oldham coupling must have an interior bore which will allow it to slide as described above while remaining out of contact with several components of the compressor which are positioned radially inwardly of the bore's inner periphery. Moreover, the Oldham coupling ring must have sufficient wall thickness throughout its entire periphery such that the part will be sufficiently robust for reliable use. Finally, the inner periphery of the Oldham coupling ring cannot be so complex that it is difficult or unduly expensive to manufacture.
SUMMARY OF THE INVENTION
In the disclosed embodiment of this invention, an Oldham coupling ring has a generally cylindrical inner periphery. Two opposed circular arcs are centered on a common axis, and are associated with the portions of the Oldham coupling which are received in keyways in the crankcase. The circular portions have a pair of angled portions at each of their circumferential extremes. The angled portions merge into flat portions which are positioned radially inwardly of the slots on the ring which receive keys from the orbiting scroll member. The inventive Oldham coupling ring is a relatively simple part to manufacture, in that its inner periphery is formed to be generally circular, with the angled portions on the flat portions being relatively simple portions to manufacture.
In another embodiment, there are three of the angled portions at each of the circumferential extends. This adds additional size to the ring at the area where the angled portions are merging into the flat portions.
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 through a scroll compressor incorporating this invention.
FIG. 2
is a plan view of an Oldham coupling according to the present invention.
FIG. 3
is another sectional view.
FIG. 4
shows another embodiment.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
A scroll compressor
20
is shown in
FIG. 1
having an orbiting scroll
22
being driven by a shaft
24
. An Oldham coupling
26
is positioned intermediate a crankcase
25
and the orbiting scroll
22
. As is known, the shaft
24
drives the orbiting scroll
22
through a slider block connection
27
. The Oldham coupling prevents the orbiting scroll
24
from rotating, and instead transmits the rotation from the shaft
24
into constrained orbiting movement of the orbiting scroll
22
. As is also known, when the orbiting scroll
22
orbits, it orbits relative to a non-orbiting scroll
29
. This orbiting movement compresses a refrigerant trapped in compression chambers
31
.
As shown in
FIGS. 2 and 3
, the Oldham coupling ring
26
functions generally as known in the art. Keyways from orbiting scroll
22
receive keys
28
. Keys
30
are formed at diametrically opposed positions which are spaced generally by 90° from the keys
28
. The keys
30
fit into slots in the crankcase
25
. As is known, during movement, the Oldham coupling ring
26
will slide vertically upwardly and downwardly in the direction illustrated in
FIG. 2
, and within the slots of crankcase
25
. This is as known in the art. During this movement, the keys
28
are guided into keyways on orbiting scroll
22
, preventing the orbiting scroll
22
from rotating, and instead constrain the orbiting scroll
22
to orbit.
As can be appreciated, as the Oldham coupling
26
moves, it must avoid portions of the crankcase
25
inwardly of its bore, along with any other internal structure. Thus, it is desirable to provide sufficient clearance within the inner periphery of the ring
26
to avoid contact with any such component. The present invention provides sufficient clearance, while still maintaining an easy to manufacture configuration. As shown, opposed circular arcs
32
are positioned radially inwardly of the keys
30
. The arcs
32
are each centered on a common center
34
. Flat portions
36
are positioned radially inwardly of the keys
28
. Angled portions
38
and
40
connect each flat
36
to one circumferential end of an arc
32
. The ring
26
provides sufficient clearance space, while still providing a relatively easy to manufacture configuration. The prior art had more complex configurations, and this invention is thus an improvement. Moreover, the prior art had configurations that would often result in undesirably thin wall sections that resulted in the ring not being sufficiently robust.
FIG. 4
shows another preferred embodiment of the ring
100
. In ring
100
, there are three angled portions
138
,
140
and
142
. This provides additional wall size in the area immediately adjacent to the point where the angled portions merge into the flat portion
36
.
A preferred embodiment of this invention has been disclosed, however, 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.
Claims
- 1. A scroll compressor comprising:a first scroll member having a base and a generally spiral wrap extending from 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 member interfitting to define compression chambers; a shaft driven to rotate, said shaft being operatively connected to drive said second scroll member, a crankcase for supporting said second scroll member; and an Oldham coupling ring positioned between a guiding structure and said second scroll member, said Oldham coupling ring having diametrically opposed circular portions centered on a common point, and having flat portions spaced by 90° from said circular portions, said flat portions being connected to circumferential ends of said circular portion by angled portions, said angled portions being line segments which are not parallel to said flat portion, and said Oldham coupling ring being operatively connected to both said guiding structure and said second scroll member to cause said second scroll member to orbit when said shaft rotates.
- 2. A scroll compressor as recited in claim 1, wherein said guiding structure is on said crankcase.
- 3. A scroll compressor as recited in claim 2, wherein said circular arcs are positioned radially inwardly of structure to be received on said crankcase, and said flat portions are positioned radially inwardly of structure associated with said second scroll member.
- 4. A scroll compressor as recited in claim 3, wherein keys are formed on said ring and extend into slots in said crankcase, and said ring further including keys extending into slots from said second scroll member.
- 5. A scroll compressor as recited in claim 1, wherein there are at least two of said angled portions.
- 6. A scroll compressor as recited in claim 5, wherein there are three of said angled portions.
US Referenced Citations (5)
Foreign Referenced Citations (3)
Number |
Date |
Country |
09-032748 |
Feb 1997 |
JP |
11-182459 |
Jul 1999 |
JP |
11-324943 |
Nov 1999 |
JP |