U.S. patent application number 09/782123 was filed with the patent office on 2002-08-15 for oil supply cross-hole in orbiting scroll member.
This patent application is currently assigned to Scroll Technologies. Invention is credited to Sun, Zili, Witham, Robert Carl.
Application Number | 20020110471 09/782123 |
Document ID | / |
Family ID | 25125039 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020110471 |
Kind Code |
A1 |
Sun, Zili ; et al. |
August 15, 2002 |
OIL SUPPLY CROSS-HOLE IN ORBITING SCROLL MEMBER
Abstract
A scroll compressor includes an oil supply cross-hole extending
radially outwardly to the outer peripheral surface of the base of
the orbiting scroll. The cross-hole supplies lubricant against the
crankcase towers such that lubricant is supplied to both the Oldham
coupling and the seals for the back pressure chamber. The
cross-hole is preferably positioned to be between 80.degree. and
90.degree. downstream from the beginning of the orbiting scroll
wrap. In this position, adequate oil will be supplied to lubricate
the Oldham coupling and the seal, while at the same time, it is
unlikely that an undue amount of lubricant will be allowed into the
scroll compressor chambers.
Inventors: |
Sun, Zili; (Arkadelphia,
AR) ; Witham, Robert Carl; (Arkadelphia, AR) |
Correspondence
Address: |
THEODORE W. OLDS
CARLSON, GASKEY & OLDS
400 W. Maple Road, Ste. 350
Birmingham
MI
48009
US
|
Assignee: |
Scroll Technologies
|
Family ID: |
25125039 |
Appl. No.: |
09/782123 |
Filed: |
February 13, 2001 |
Current U.S.
Class: |
418/55.4 ;
418/55.5; 418/55.6; 418/94; 418/99 |
Current CPC
Class: |
F04C 18/0215 20130101;
F04C 29/02 20130101 |
Class at
Publication: |
418/55.4 ;
418/55.5; 418/55.6; 418/94; 418/99 |
International
Class: |
F04C 029/02; F04C
018/04 |
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 its base; a crankcase for supporting said second scroll
member, said second scroll member being driven to orbit relative to
said first scroll member; a driveshaft being driven by a motor for
causing said second scroll member to orbit, and a coupling
positioned to constrain said second scroll member to orbit; and oil
supply port passing through said drive shaft, and a oil cross-hole
extending through said base of said second scroll member to an
outer peripheral surface of said second scroll member, said oil
support cross-hole being at a location between 0 and 180.degree.
measured from a beginning point of said wrap of said second scroll
member measured in a downstream direction.
2. A scroll compressor as recited in claim 1, wherein said
crankcase includes a number of crankcase towers extending upwardly
and along an outer peripheral surface of said second scroll member,
and said cross-hole being circumferentially aligned with one of
said crankcase towers.
3. A scroll compressor as recited in claim 1, wherein said
cross-hole is positioned from said beginning point of said scroll
wrap by an angle between 30.degree. and 90.degree. in a downstream
direction.
4. A scroll compressor as recited in claim 3, wherein said angle is
between 80.degree. and 90.degree..
5. A scroll compressor as recited in claim 1, wherein a pair of
spaced seals are positioned in said crankcase for defining a back
pressure chamber, said oil supply ports supplying oil to said
seals.
6. A scroll compressor as recited in claim 5, wherein said oil
supply port further supplying oil to said coupling.
7. 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 its base; a crankcase for supporting said second scroll
member, said second scroll member being driven to orbit relative to
said first scroll member, said crankcase including a number of
crankcase towers extending upwardly and along an outer peripheral
surface of said second scroll member; a drive shaft being driven by
a motor for causing said scroll member to orbit, and a coupling
positioned to constrain said second scroll member to orbit; and an
oil supply port passing through said drive shaft, and a oil
cross-hole extending through said base of said second scroll member
to an outer peripheral surface of said second scroll member, said
oil support cross-hole being at a location between 30.degree. and
90.degree. measured from a beginning point of said wrap of said
second scroll member measured in a downstream direction, said
cross-hole also being circumferentially aligned with one of said
crankcase towers.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a unique position for an oil
supply cross-hole in the orbiting scroll of a scroll
compressor.
[0002] Scroll compressors are becoming widely utilized in
refrigerant applications. In a scroll compressor first and second
scroll members each have a base and a generally spiral wrap
extending from a base. The wraps interfit to define compression
chambers. One of the scroll members is caused to orbit relative to
the other, and as the scroll member orbits the compression chambers
decrease in volume to compress an entrapped refrigerant.
[0003] One challenge with scroll compressors involves holding the
two scroll members together as the refrigerant begins to be
compressed. The opposed wraps must contact the base of the opposed
scroll member to define the compression chambers. However, the
entrapped refrigerant creates a separating force tending to bias
the two scroll members away from each other. Thus, it is typical in
scroll compressors to tap a portion of the refrigerant to a back
pressure chamber. The back pressure chambers are typically defined
by seals within a crankcase which supports the orbiting scroll.
Further, outwardly of the seals an Oldham coupling constrains the
orbiting scroll to orbiting movement, even though it receives a
rotary input from a rotary motor.
[0004] One challenge in the prior art is supplying adequate
lubricant to the interface between the orbiting scroll and the
crankcase to provide sufficient lubrication to both the coupling
and the seals.
[0005] The crankcase is secured to the non-orbiting scroll through
a plurality of structures called crankcase towers. In the prior
art, a cross-hole extends through the base of the orbiting scroll
to supply lubricant to the outer periphery of the orbiting scroll
at a circumferential location generally aligned with one of the
crankcase towers. Lubricant is supplied through this cross-hole to
the seals and to the coupling.
[0006] In the prior art, the cross-hole was formed at a location
slightly upstream of the suction inlet into the scroll compressor.
With such a location, there is the potential of lubricant being
entrained into the refrigerant being compressed. This is
undesirable.
SUMMARY OF THE INVENTION
[0007] In the disclosed embodiment of this invention, a cross-hole
extends from the inner periphery of the bore of the orbiting scroll
radially outwardly to the outer peripheral surface of the orbiting
scroll to supply lubricant against a crankcase tower. Preferably
this cross-hole is circumferentially downstream from the beginning
of the orbiting scroll wrap, and less than 180.degree. downstream
from the beginning of the orbiting scroll wrap. More preferably,
the cross-hole is between 30.degree. and 90.degree. downstream of
the beginning of the scroll wrap. In an illustrated embodiment the
cross-hole is a few degrees above 80 downstream of the beginning of
the scroll wrap.
[0008] In this location, the cross-hole is directed at a crankcase
tower, which is desirable for providing adequate lubrication.
Further, the position is far enough downstream that lubricant will
not likely be drawn into the compression chambers in any undue
quantities.
[0009] 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
[0010] FIG. 1 is a cross-sectional view of a scroll compressor
according to this invention.
[0011] FIG. 2 is a plan view of an orbiting scroll assembly
incorporating the present invention.
[0012] FIG. 3 shows the prior art.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0013] A scroll compressor 20 is illustrated in FIG. 1 having a
housing shell 22 enclosing a quantity of oil 24. A shaft 26 is
driven to rotate by an electric motor 28 within the housing 22.
Lubricant is drawn from sump 24 upwardly through a lubricant supply
passage 30. An orbiting scroll member 32 has a downwardly extending
boss 34 surrounding eccentric pin 35 from the shaft. Lubricant is
supplied through the port 30 upwardly into the area of the boss 34.
This lubricant extends through the base 38 of the orbiting scroll
32 and through a cross-hole 40 to a cross-hole outlet 39 positioned
circumferentially aligned with a crankcase tower 42. As shown, the
orbiting scroll 32 has a generally spiral wrap 36. The orbiting
scroll faces and is meshed with a non-orbiting scroll 44 having its
own wrap 46. The two wraps of the two scroll members 36 and 44
compress the entrapped refrigerant and deliver it to a discharge
opening 48. An Oldham coupling 49 constrains the orbiting scroll 32
for orbital movement relative to the non-orbiting scroll 44. As
shown, a back pressure tap 17 taps a refrigerant to a back pressure
chamber defined between seals 18 and 19.
[0014] As is known, the purpose of the cross-hole 40 is to deliver
lubricant against the inner periphery of the crankcase tower 40
such that there will be sufficient lubricant for the seal 19 and
the coupling 49.
[0015] As shown in FIG. 2, most preferably, the cross-hole 40 is
positioned by an angle A from a beginning point 56 of the orbiting
scroll wrap 36. As shown the outlet 39 faces a crankcase tower 42.
Further, as shown, the suction inlet 50 into the scroll compressor
is at a position slightly upstream of the beginning point 56 of the
scroll wrap. The direction of orbital movement of the scroll wrap
is counter-clockwise in the view shown in FIG. 2. Other crankcase
towers 52 and 54 are shown circumferentially spaced around the
orbiting scroll member 32.
[0016] The angle A is preferably chosen to be greater than 0 but
less than 180.degree.. In this way, the outlet 39 is positioned
such that it is unlikely lubricant will be mixed into the suction
flow 50. Further, the outlet 39 is preferably circumferentially
aligned with a crankcase tower 42. With orbital movement of the
orbiting scroll, the relative location of the outlet 39 and the
tower will change, however, throughout the orbital movement, it is
likely that the outlet 39 will preferably be aligned with a portion
of the crankcase tower 42. In this way, the tower 42 can provide a
deflection surface for deflecting the oil back inwardly toward the
seal and coupling. More preferably, it is preferred that the angle
A be between 30.degree. and 90.degree.. The preferred angle is
slightly over 80.degree. as is illustrated in FIG. 2.
[0017] FIG. 3 shows the prior art wherein a cross-hole 50 was
positioned further upstream from the position illustrated in FIG.
2. The outlet 102 was aligned with the crankcase tower 54. In this
position there was the possibility of lubricant mixing into the
suction flow 50, which is undesirable.
[0018] Although a preferred embodiment of this invention has been
disclosed, a worker in this art would recognize that 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.
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