U.S. patent application number 13/156606 was filed with the patent office on 2012-09-27 for counterweight incorporated into slider block for scroll compressor.
Invention is credited to Patrice Bonnefoi, Gregory W. Hahn, Ravi Mantrala.
Application Number | 20120244026 13/156606 |
Document ID | / |
Family ID | 44550270 |
Filed Date | 2012-09-27 |
United States Patent
Application |
20120244026 |
Kind Code |
A1 |
Hahn; Gregory W. ; et
al. |
September 27, 2012 |
COUNTERWEIGHT INCORPORATED INTO SLIDER BLOCK FOR SCROLL
COMPRESSOR
Abstract
A slider block has an inner bore which receives an eccentric
pin, and a generally flat drive surface over a limited
circumferential extent to be engaged by a flat drive surface on an
eccentric pin. A counterweight is positioned on an outer periphery
of the slider block. The counterweight has a center line defining a
first plane. A second plane is defined parallel to the first plane,
with the second plane including a point on the flat drive surface
of the slider block, with the flat drive surface of the slider
block including a third plane, and a non-zero angle defined between
the second and third planes.
Inventors: |
Hahn; Gregory W.;
(Arkadelphia, AR) ; Bonnefoi; Patrice;
(Saint-Didier au Mont d'Or, FR) ; Mantrala; Ravi;
(Arkadelphia, AR) |
Family ID: |
44550270 |
Appl. No.: |
13/156606 |
Filed: |
June 9, 2011 |
Current U.S.
Class: |
418/55.1 |
Current CPC
Class: |
F04C 18/0215 20130101;
F04C 2240/807 20130101; F04C 23/008 20130101 |
Class at
Publication: |
418/55.1 |
International
Class: |
F01C 1/02 20060101
F01C001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 2011 |
FR |
11/52384 |
Claims
1. A scroll compressor comprising: a first scroll member and a
second scroll member, each of said first and second scroll members
having a base and a generally spiral wrap extending from their
base; said second scroll member having a boss extending away from
said base in an opposed direction to said wrap; a motor for driving
a drive shaft, said drive shaft having an eccentric pin, said
eccentric pin extending upwardly into a slider block, said slider
block being received between said pin and an interior surface of
said boss, and said slider block having an inner bore which
receives said eccentric pin, and having a generally flat drive
surface over a limited circumferential extent to be engaged by a
flat drive surface on said eccentric pin; a counterweight
positioned on an outer periphery of said slider block; and said
counterweight having a center line, and a second line being defined
parallel to said center line, with said second line including a
point on said flat drive surface of said slider block, with said
flat drive surface of said slider block defining a plane, and a
non-zero angle defined between said second line and said plane.
2. The scroll compressor as set forth in claim 1, wherein said
angle is between 6.degree. and 40.degree..
3. The scroll compressor as set forth in claim 2, wherein a
locating feature is provided between said counterweight and said
slider block.
4. The scroll compressor as set forth in claim 3, wherein said
locating feature is a flat portion provided between the
counterweight and the slider block.
5. The scroll compressor as set forth in claim 2, wherein said
angle is between 5.degree. and 20.degree..
6. The scroll compressor as set forth in claim 5, wherein said
angle is between 7.5.degree. and 17.5.degree..
7. The scroll compressor as set forth in claim 1, wherein said
counterweight having a ring portion surrounding said slider block,
and an extending portion extending upwardly and partially
surrounding an outer peripheral surface of said boss.
8. The scroll compressor as set forth in claim 7, wherein said
extending portion having an angled surface extending from said ring
portion into said extending portion.
9. The scroll compressor as set forth in claim 8, wherein a second
angle is defined from the angled surface relative to a plane which
is perpendicular to a drive axis of the drive shaft, the second
angle being between 20.degree. and 60.degree..
10. The scroll compressor as set forth in claim 1, wherein a
circumferential extent of said extending portion is formed at a
third angle relative to a top surface of said ring portion, with
said third angle being between 95.degree. and 125.degree..
11. The scroll compressor as set forth in claim 1, wherein a
locating feature is provided between said counterweight and said
slider block.
12. The scroll compressor as set forth in claim 11, wherein said
locating feature is a flat portion provided between the
counterweight and the slider block.
13. The scroll compressor as set forth in claim 1, wherein a
hydrodynamic oil bearing is positioned between an inner surface of
said boss, and an outer surface of said slider block.
Description
BACKGROUND
[0001] This application relates to a scroll compressor wherein a
counterweight is incorporated into the drive connection such that
it surrounds a slider block.
[0002] Scroll compressors are known and have become widely utilized
in refrigerant compression applications. In a typical scroll
compressor, a first scroll member has a base and a generally spiral
wrap extending perpendicularly from the base. The first scroll
member interfits with the wraps of a second scroll member. The
second scroll member is driven to orbit by a drive connection
relative to the first scroll member, and as it orbits, the wraps
move relative to each other to entrap refrigerant, and then
decrease the size of compression chambers to compress the
refrigerant.
[0003] One standard type of drive connection includes a so-called
"slider block." The slider block surrounds an eccentric pin on a
drive shaft. The slider block interfits upwardly into a boss in the
second scroll member. As the shaft is driven to rotate, the
eccentric pin moves eccentrically, and a relatively flat drive face
on the pin engages a relatively flat drive face on the slider block
to cause the wraps to be held in contact, and the wraps orbit
relative to each other.
[0004] Counterweights are also utilized in scroll compressors. It
has been known to incorporate a counterweight into the area of the
drive connection, such that it surrounds and is fixed to the slider
block.
SUMMARY
[0005] A scroll compressor has a first scroll member and a second
scroll member, each of having a base and a generally spiral wrap
extending from their base. The second scroll member has a boss
extending away from the base in an opposed direction to the wrap. A
motor drives a drive shaft, which has an eccentric pin extending
upwardly into a slider block. The slider block is received between
the pin and an interior surface of the boss. The slider block has
an inner bore which receives the eccentric pin, and a generally
flat drive surface over a limited circumferential extent to be
engaged by a flat drive surface on the eccentric pin. A
counterweight is positioned on an outer periphery of the slider
block. The counterweight has a center line defining a first plane.
A second plane is defined parallel to the first plane and including
a point on the flat drive surface of the slider block, with the
flat drive surface of the slider block including a third plane, and
a non-zero angle defined between the second and third planes
being.
[0006] These and other features of the present invention can be
best understood from the following specification and drawings, of
which the following is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a cross-sectional view through a scroll
compressor.
[0008] FIG. 2A is a top view of a counterweight.
[0009] FIG. 2B is a cross-section along line A-A of FIG. 2A.
[0010] FIG. 2C is a bottom view of a combined counterweight and
slider block.
[0011] FIG. 2D shows one graphical feature of the FIG. 2C
combination.
[0012] FIG. 3 shows an alternative feature.
DETAILED DESCRIPTION
[0013] A compressor 20 is illustrated in FIG. 1 having a drive
motor 122 driving a shaft 24. Shaft 24 is provided with an
eccentric pin 26. A slider block 28 has a bore surrounding the
eccentric pin 26. As is known, the slider block and pin each have a
generally cylindrical section over a good deal of circumferential
extent of the two. However, a relatively flat drive face is formed
on both the eccentric pin and the slider block over a limited
circumferential extent. These two relatively flat drive surfaces
are brought into contact to cause an orbiting scroll member 21 to
orbit relative to a non-orbiting scroll member 22. In addition, a
non-rotating coupling, such as an Oldham coupling, may be
positioned to cause the orbiting movement, as known. While the term
"flat faces" have been utilized to describe surfaces on the
eccentric pin and slider block, in practice, there may be a slight
curve or barrel shape to one or both, and the term "flat" should be
interpreted with this in mind.
[0014] A counterweight 30 surrounds the slider block 28. As shown,
a cylindrical ring 36 on the counterweight 30 surrounds the slider
block 28, and an extending portion 34 extends upwardly such that it
circumferentially surrounds a boss 32 that receives the slider
block 28 and eccentric pin 26. As shown, a hydrodynamic oil bearing
400 is positioned intermediate the inner periphery of the boss 32,
and the outer periphery of the slider block 28.
[0015] As is well known in scroll compressors, refrigerant to be
compressed enters the compressor 20 through a suction tube 160, and
flows into a suction pressure chamber 101 surrounding the motor
122. That refrigerant passes upwardly into compression chambers 105
formed between the scroll members, and is compressed and delivered
into a discharge pressure chamber 102. From the discharge pressure
chamber 102, the refrigerant flows outwardly through a tube
103.
[0016] FIG. 2A is a bottom view of the counterweight 30. As shown,
a bore 40 is formed in the interior of the counterweight, and is
tightly received on the outer periphery of the slider block 28. The
counterweight 30 has a center line 59, which is a center of weight
for the counterweight.
[0017] As shown in FIG. 2B, an angle A is defined at a ramp outer
portion 50 which extends upwardly into the extending portion 34.
Angle A may be between 20.degree. and 60.degree. . In some
embodiments, this angle may be omitted entirely.
[0018] As shown in FIG. 2C, when the slider block 28 is received
within the bore 40, there is a flat drive face 62 on the interior
bore 60 of the slider block 28. The outer periphery of the
eccentric pin 26 is shown, and can be seen to have a mating drive
face 99. As shown, the outer periphery of the eccentric pin 26 also
has a cylindrical portion 98 at locations spaced from the flat
drive surface 99. Similarly, there is a cylindrical portion 61
forming part of the bore 60 of the slider block 28.
[0019] As shown, the inner periphery of the bore 40 is provided
with a flat 300, as is the outer periphery of the slider block 28.
This will ensure proper positioning of the counterweight on the
slider block.
[0020] As shown in FIG. 2D, a line 159 can be defined which is
parallel to the line 59. Line 159 has a point X which is on the
flat drive surface 62. The plane of the flat drive surface 62, and
the line 159, define an angle B. In practice, this angle is
non-zero and may be between 6.degree. and 40.degree. , and more
particularly between 5.degree. and 20.degree. , and more
particularly, between 6.degree. and 20.degree.. In one embodiment,
the angle was between 7.5.degree. and 17.5.degree..
[0021] By having this relationship between the flat drive surface
62 and the counterweight center axis 59, better control of the
operation of the scroll compressor is achieved. The angle provides
extra closing force, and better control to hold the wraps in
contact during compression. The centrifugal force created by the
moving elements has a part in holding the wraps in contact, and the
use of the counterweight will somewhat limit that centrifugal
force. As such, this angle provides additional force. On the one
hand, if the angle is too small, there may not be enough force, but
excessive force would also be undesirable. As such, the mentioned
ranges provide valuable benefits.
[0022] FIG. 3 shows an alternative counterweight 198, wherein the
extending portion 200 and the ring 202 are generally as shown in
the earlier embodiment. However, a circumferential edge 204 of the
extending portion 200 is formed at an angle C relative to an upper
surface of the ring portion 202. This surface assists in directing
oil flow to appropriate surfaces. In embodiments, the angle C may
be between 95.degree. and 125.degree. , and in one embodiment was
110.degree..
[0023] Although an embodiment of this invention has been disclosed,
a worker of ordinary skill 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.
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