U.S. patent application number 09/725364 was filed with the patent office on 2002-05-30 for scroll compressor having clutch with powered reverse rotation protection.
This patent application is currently assigned to Scroll Technologies. Invention is credited to Barito, Thomas, Bush, James W., Hahn, Greg, Hill, Joe T., Hugenroth, Jason, Sun, Zili, Williams, John R., Zamudio, Carlos.
Application Number | 20020064472 09/725364 |
Document ID | / |
Family ID | 24914244 |
Filed Date | 2002-05-30 |
United States Patent
Application |
20020064472 |
Kind Code |
A1 |
Bush, James W. ; et
al. |
May 30, 2002 |
SCROLL COMPRESSOR HAVING CLUTCH WITH POWERED REVERSE ROTATION
PROTECTION
Abstract
A scroll compressor is provided with a clutch to minimize or
eliminate the detrimental effects of reverse rotation. Generally,
the clutch prevents rotation of the shaft during both powered and
unpowered reverse rotation. The clutch could be subject to damage
during powered reverse rotation, and thus a clutch protection
mechanism is incorporated that will prevent the clutch from moving
to an actuated position if powered reverse rotation occurs.
Inventors: |
Bush, James W.;
(Skaneateles, NY) ; Williams, John R.; (Bristol,
VA) ; Sun, Zili; (Arkadelphia, AR) ; Zamudio,
Carlos; (Arkadelphia, AR) ; Hugenroth, Jason;
(Hope, AR) ; Hahn, Greg; (Arkadelphia, AR)
; Barito, Thomas; (Arkadelphia, AR) ; Hill, Joe
T.; (Bristol, VA) |
Correspondence
Address: |
THEODORE W. OLDS
CARLSON, GASKEY & OLDS
Suite 350
400 W. Maple Road
Birmingham
MI
48009
US
|
Assignee: |
Scroll Technologies
|
Family ID: |
24914244 |
Appl. No.: |
09/725364 |
Filed: |
November 29, 2000 |
Current U.S.
Class: |
418/55.1 ;
418/69 |
Current CPC
Class: |
F04C 28/28 20130101;
F04C 29/0057 20130101; F04C 2270/72 20130101 |
Class at
Publication: |
418/55.1 ;
418/69 |
International
Class: |
F04C 018/04 |
Claims
1. A scroll compressor comprising: a first scroll member having a
base and a generally spiral wrap extending from the wrap; a second
scroll member having a base and a generally spiral wrap extending
from said base; a driveshaft having eccentric pin drivingly
engaging said second scroll to cause it to move in an orbital
fashion; and a clutch for selectively protecting said compressor
during reverse rotation, said clutch moving to an actuated position
when reverse rotation occurs, and a clutch protection mechanism
allowing said clutch to move to said actuated position during
unpowered reverse rotation but preventing said clutch from moving
during powered reverse rotation.
2. A scroll compressor as recited in claim 1, wherein said clutch
rotates to said actuated position from a normal position and said
clutch protection mechanism not preventing said clutch from
rotating during unpowered reverse rotation.
3. A scroll compressor as recited in claim 2, wherein said second
scroll member has an extending hub on said base opposite said wrap,
said hub receiving a slider block, said eccentric pin extending
into said slider block, and said clutch has an inner bore
surrounding said slider block and at least one of said inner bore
and said slider block being provided with a radially extending lug,
said slider block being caused to move into contact with said inner
bore at said lug upon the occurrence of powered reverse rotation
and to prevent said clutch from rotating.
4. A scroll compressor as recited in claim 3, wherein said clutch
is provided with engagement surfaces on radially outer surfaces
which selectively engage a bore in a crankcase, said clutch moving
to engage said surfaces in said bore, and said clutch protection
mechanism preventing such movement.
5. A scroll compressor as recited in claim 3, wherein said
eccentric pin selectively engages an actuation pin on an inner bore
of said slider block when powered reverse rotation occurs, said
engagement causing said slider block to move such that it contacts
said engagement lug preventing rotation of said clutch.
6. A scroll compressor comprising: a first scroll member having a
base and a generally spiral wrap extending from the wrap; a second
scroll member having a base and a generally spiral wrap extending
from said base, said second scroll member having a downwardly
extending boss receiving a slider block; a driveshaft having
eccentric pin extending upwardly into said slider block; and a
clutch for selectively protecting said compressor during reverse
rotation, said clutch moving to an actuated position when reverse
rotation occurs, and giving a clutch protection mechanism allowing
said clutch to move to said actuated position during unpowered
reverse rotation but preventing said clutch from moving during
powered reverse rotation, said clutch rotating to said actuated
position from a normal position and said clutch protection
mechanism preventing said clutch from rotating, said clutch having
an inner bore surrounding said slider block, at least one of said
inner bore and said slider block being provided with a radially
extending lug, said slider block being caused to move into contact
with said inner bore at said lug upon the occurrence of powered
reverse rotation and prevent said clutch from rotating, said clutch
being provided with engagement surfaces on radially outer surface
which selectively engage a bore and crankcase, said clutch moving
to engage said surfaces in said bore, and said clutch protection
mechanism preventing such movement during powered reverse rotation,
said eccentric pin having a surface selectively engaging an
actuation pin on an inner bore of said slider block when powered
reverse rotation occurs, said surface causing said slider block to
move such that it contacts said engagement lug, preventing rotation
of said clutch.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to an improvement to a clutch for
preventing reverse rotation in scroll compressors that prevents the
clutch from engaging when powered reverse rotation occurs.
[0002] Scroll compressors are becoming widely utilized in
refrigerant compression applications. In a scroll compressor, a
pair of scroll members each have a base and a generally spiral wrap
extending from the base. The spiral wraps interfit to define
compression chambers. One of the two scroll members is caused to
orbit relative to the other, and as the two orbit compression
chambers defined between the interfitting scroll wraps decrease in
volume, compressing a refrigerant.
[0003] One problem with scroll compressors is that they are
designed to orbit in a single direction. If for some reason the
scroll member orbits in a reverse direction, the results are
undesirable.
[0004] Reverse rotation can occur in one of two ways. First,
unpowered reverse rotation can occur at shutdown of the compressor.
At some point, the force from the entrapped refrigerant can cause
the orbiting scroll to be driven in the reverse direction. This is
generally a short transient phenomena, and results in undesirable
noise.
[0005] Another type of reverse rotation is powered reverse
rotation. This type of reverse rotation generally occurs when a
motor for driving the orbiting scroll is miswired. Powered reverse
rotation can occur for longer periods of time, and will often
result in damage to the compressor.
[0006] One proposed solution to reverse rotation is the use of a
one-way clutch within the scroll compressor. In one type of clutch,
the compressor is provided with a clutch member that is normally in
a first position where it does not affect transmission of orbiting
movement to the orbiting scroll, nor does it affect the scroll
wraps being kept in engagement with each other sealing and defining
compression chambers. In this known clutch, if reverse rotation
occurs, the clutch member will rotate, and surfaces will lock and
engage surfaces within the drive housing, creating a breaking
action. This will slow or halt the reverse rotation, and will
reduce the undesirable noise mentioned above.
[0007] One such proposed clutch is shown in U.S. Pat. No.
5,545,019. This clutch is beneficial for stopping unpowered reverse
rotation. However, there has sometimes been problems with these
systems during powered reverse rotation. In particular, during
powered reverse rotation, the clutch members have sometimes been
destroyed.
[0008] The present invention is thus directed to protecting
clutches during powered reverse rotation. While the invention is
disclosed with a clutch as in the above patent, other clutches may
benefit.
SUMMARY OF THE INVENTION
[0009] In a disclosed embodiment of this invention, an eccentric
pin on a driveshaft is received within a slider block for the
orbiting scroll, as known. As further generally known, the slider
block and eccentric pin are structured such that during forward
rotation flat surfaces on the eccentric pin engage the flat
surfaces on the slider block to drive the orbiting scroll and also
hold the orbiting scroll wrap against the non-orbiting scroll
wrap.
[0010] However, should powered reverse rotation occur, a surface on
the eccentric pin will engage a surface on the slider block, and
cause the slider block to move out of position. The slider block
will then engage a lug on an inner periphery of the clutch. With
the slider block engaging the lug, the clutch will not be allowed
to rotate to its engaged position. This movement of the slider
block will not occur during unpowered reverse rotation.
[0011] In this way, the clutch will brake the shaft during
non-powered reverse rotation, but the inventive structure prevents
the clutch from engaging during non-powered reverse rotation. Thus,
the clutch will be protected.
[0012] 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
[0013] FIG. 1 shows a Prior Art scroll compressor.
[0014] FIG. 2 is a cross-sectional view showing one feature known
in the prior art.
[0015] FIG. 3 shows another view of the Prior Art FIG. 2 structure
moved to a distinct position.
[0016] FIG. 4 shows an engaged view of a Prior Art clutch as shown
in FIGS. 2 and 3.
[0017] FIG. 5 shows an inventive structure in a normal
position.
[0018] FIG. 6 shows the inventive structure in a position after
undergoing powered reverse rotation.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0019] FIG. 1 shows a scroll compressor 20 as is generally known in
the prior art. A non-orbiting scroll 22 is held in a position where
its wrap engages the wrap of an orbiting scroll 24. A crankcase 26
supports the orbiting scroll 24. A clutch 28 surrounds a driveshaft
30 having an eccentric pin 32 received within a slider block 34. A
hub 36 from the orbiting scroll 24 surrounds the slider block
34.
[0020] As shown in FIG. 2, the clutch 28 is provided with surfaces
38 and 40 which selectively engage surfaces 42 on the shaft 30.
During normal direction rotation, the clutch member is free to
rotate within a bore 49 in the crankcase. A end wall 44 of the
clutch has an upwardly extending hub 46. Friction pads 48 and 50
extend outwardly from the hub 46. In the position shown in FIG. 2,
the entire structure is free to rotate as the orbiting scroll
orbits. As described in greater detail in U.S. Pat. No. 5,545,219,
this structure is designed to be in the position shown in FIG. 2
during normal rotation.
[0021] FIG. 3 shows the movement of the clutch 28 as rotation slows
at shutdown. As shown, one friction pad 48 now engages the inner
surface 49. The other friction pad 50 has yet to engage. The clutch
will now begin to slow rotation of the shaft.
[0022] FIG. 4 shows the engagement of the friction pads 48 and 50
with a surface 49 as will occur when reverse rotation begins. The
engagement of the friction pads 48 and 50 with surface 49 tends to
slow or stop reverse rotation of the shaft. Again, the above
description is as known in the art, and described in greater detail
in the above-referenced U.S. Patent. The above-referenced U.S.
Patent also predicted that the clutch would be beneficial for
preventing powered reverse rotation. However, in practice, the
clutches are often ruined when they experience powered reverse
rotation when the motor has sufficient strength when powered in
reverse to overcome the friction of pads 48 and 50. This can
happen, for example, when the motor is a three phase induction
motor.
[0023] FIG. 5 shows an improvement to the system of FIGS. 1-4. The
eccentric pin 32 is provided with a flat face 52 selectively
engaging a flat face 54 on the slider block 34, as known. The bore
58 of the slider block other than the flat surface 54 further has
an actuating pin 60. Actuating pin 60 is selectively aligned with a
flat 56 on the eccentric pin 32. A lug 62 extends radially inwardly
from the hub 46 of the clutch 28. During forward rotation, the
eccentric pin and slider block are held in the position shown in
FIG. 5. In this position, the eccentric pin is forced in a
direction such that its flat surface 52 is driven against the flat
surface 54 and orbiting movement is transmitted to the orbiting
scroll as is known.
[0024] In the event of unpowered reverse rotation, the forces
between the slider block 34 and eccentric pin 32 are generally
unchanged. The slider block 34 and drive shaft 30 slow to a stop
under the influence of high pressure vapor trapped between the
wraps of scrolls 22 and 24 and begin to accelerate in a reverse
direction as the vapor begins to reexpand. Slider block 34 and
eccentric pin 32 remain in normal engagement throughout this
process and clutch 28 operated normally as is known. Note that
"normal engagement" between slider block 34 and eccentric pin 32
may include some sliding motion between surfaces 52 and 54 as is
known. Such sliding motion does not affect the operation of clutch
28.
[0025] However, should powered reverse rotation occur, the
eccentric pin will initially move in a direction away from (to the
right) from the flat surface 54 within the slider block 34. The
surface 56 will contact the actuation pin 60. This then causes the
slider block 34 to move to a position such that it contacts the lug
62. Once the lug 62 has been contacted, the rotating movement
between the FIG. 2 position and the FIGS. 3 and 4 position of the
clutch 28 is prevented. Thus, the clutch will be allowed to operate
during unpowered reverse rotation, but prevented from operating
during powered reverse rotation.
[0026] A worker in this art would know how to design an eccentric
pin and slider block combination that would have the
above-described movement.
[0027] While a particular clutch has been illustrated, and a
particular arrangement of clutch protector has been illustrated, it
should be understood that a worker in this art would be able to
design other clutch protection mechanisms and that such clutch
protection mechanisms would also protect other type clutches. For
that reason the following claims should be studied to determine the
true scope and content of this invention.
* * * * *