In a scroll compressor, under conditions favoring reverse operation, the scroll wraps are separated so as to provide a continuous, unimpeded path through the scrolls. spring bias, a repositioning of driving contact areas and/or force areas can be used singly or in combination to cause separation of the wraps.
|
0. 1. A scroll compressor means including a pair of scrolls one of which being an orbiting scroll, a slider block and a crankshaft wherein said orbiting scroll has a hub with a bore which has an axis and which receives said slider block, and said crankshaft has an axis of rotation and a drive pin which is received in a bore in said slider block, one of said pin and said slider block having a flat surface normally engaged by the other one of said pin and said slider block, said bore in said slider block being larger than said pin and generally coaxial with said bore in said hub and said drive pin acting through said slider block to drive said orbiting scroll during normal operation and said orbiting scroll tending to act through said slider block to drive said drive pin and crankshaft during reverse operation and pressure equalization through said compressor means at shutdown, reverse rotation prevention means comprising:
said orbiting scroll and said slider block being movable with respect to said drive pin along said flat surface between a first position in which said orbiting scroll engages the other one of said pair of scrolls during normal operation and a second position in which said orbiting scroll is separated from the other one of said pair of scrolls upon slowing down and any tendency for reverse operation and pressure equalization; centrifugal force produced solely by movement of said orbiting scroll and said slider block during normal operation tends to keep said orbiting scroll and said slider block in said first position; means for causing said orbiting scroll and said slider block to move along said flat surface from said first position to said second position under conditions associated with slowing down and reverse operation whereby said pair of scrolls is separated, an unimpeded flow path is established through said compressor means and reversing torque caused by gas loads is decreased by reduction of orbit radius.
0. 12. A scroll compressor means including a pair of scrolls one of which being an orbiting scroll, a slider block and a crankshaft wherein said orbiting scroll has a hub with a bore which has an axis and which receives said slider block, and said crankshaft has an axis of rotation and a drive pin which is received in a bore in said slider block, one of said pin and said slider block having a flat surface normally engaged by the other one of said pin and said slider block, said bore in said slider block being larger than said pin and generally coaxial with said bore in said hub and said drive pin acting through said slider block to drive said orbiting scroll during normal operation and said orbiting scroll tending to act through said slider block to drive said drive pin and crankshaft during reverse operation and pressure equalization through said compressor means at shutdown, reverse rotation prevention means comprising:
said orbiting scroll and said slider block being movable with respect to said drive pin along said flat surface between a first position in which said orbiting scroll engages the other one of said pair of scrolls during normal operation and a second position in which said orbiting scroll is separated from the other one of said pair of scrolls upon slowing down and any tendency for reverse operation and pressure equalization; centrifugal force produced solely by movement of said orbiting scroll and said slider block during normal operation tends to keep said orbiting scroll and said slider block in said first position; and means for causing said orbiting scroll and said slider block to move along said flat surface from said first position to said second position to separate said pair of scrolls during slowing down of said compressor before reverse rotation occurs, establishing an unimpeded flow path through said compressor means and decreasing reversing torque caused by gas loads by reduction of orbit radius.
0. 13. A scroll compressor means including a pair of scrolls one of which being an orbiting scroll, a slider block and a crankshaft wherein said orbiting scroll has a hub with a bore which has an axis and which receives said slider block, and said crankshaft has an axis of rotation and a drive pin which is received in a bore in said slider block, one of said pin and said slider block having a flat surface normally engaged by the other one of said pin and said slider block, said bore in said slider block being larger than said pin and generally coaxial with said bore in said hub and said drive pin acting through said slider block to drive said orbiting scroll during normal operation and said orbiting scroll tending to act through said slider block to drive said drive pin and crankshaft during reverse operation and pressure equalization through said compressor means at shutdown, reverse rotation prevention means comprising:
said orbiting scroll and said slider block being movable with respect to said drive pin along said flat surface between a first position in which said orbiting scroll engages the other one of said pair of scrolls during normal operation and a second position in which said orbiting scroll is separated from the other one of said pair of scrolls upon slowing down and any tendency for reverse operation and pressure equalization; centrifugal force produced solely by movement of said orbiting scroll and said slider block during normal operation tends to keep said orbiting scroll and said slider block in said first position; and a spring member, said spring member biasing said orbiting scroll and said slider block along said flat surface from said first position to said second position to separate said pair of scrolls during slowing down of said compressor before reverse rotation occurs, establishing an unimpeded flow path through said compressor means and decreasing reversing torque caused by gas loads by reduction of orbit radius.
0. 14. A scroll compressor means including a pair of scrolls one of which being an orbiting scroll, a slider block and a crankshaft wherein said orbiting scroll has a hub with a bore which as an axis and which receives said slider block, and said crankshaft has an axis of rotation and a drive pin which is received in a bore in said slider block, one of said pin and said slider block having a flat surface normally engaged by the other one of said pin and said slider block, said bore in said slider block being larger than said pin and generally coaxial with said bore in said hub and said drive pin acting through said slider block to drive said orbiting scroll during normal operation and said orbiting scroll tending to act through said slider block to drive said drive pin and crankshaft during reverse operation and pressure equalization through said compressor means at shutdown, reverse rotation prevention means comprising:
said orbiting scroll and said slider block being movable with respect to said drive pin along said flat surface between a first position in which said orbiting scroll engages the other one of said pair of scrolls during normal operation and a second position in which said orbiting scroll is separated from the other one of said pair of scrolls upon slowing down and any tendency for reverse operation and pressure equalization; centrifugal force produced solely by movement of said orbiting scroll and said slider block during normal operation tends to keep said orbiting scroll and said slider block in said first position; wherein said flat surface is oriented at an acute angle to a plane defined by said axis of rotation and an axis of rotation of said drive pin, said angled flat surface biasing said orbiting scroll and said slider block along said flat surface from said first position to said second position to separate said pair of scrolls during slowing down of said compressor before reverse rotation occurs, establishing an unimpeded flow path through said compressor means and decreasing reversing torque caused by gas loads by reduction of orbit radius.
0. 11. A scroll compressor means including a pair of scrolls one of which being an orbiting scroll, a slider block and a crankshaft wherein said orbiting scroll has a hub with a bore which has an axis and which receives said slider block, and said crankshaft has an axis of rotation and a drive pin which is received in a bore in said slider block, one of said pin and said slider block having flat surface normally engaged by the other one of said pin and said slider block, said bore in said slider block being larger than said pin and generally coaxial with said bore in said hub and said drive pin acting through said slider block to drive said orbiting scroll during normal operation and said orbiting scroll tending to act through said slider block to drive said drive pin and crankshaft during reverse operation and pressure equalization through said compressor means at shutdown, reverse rotation prevention means comprising:
said orbiting scroll and said slider block being movable with respect to said drive pin along said flat surface between a first position in which said orbiting scroll engages the other one of said pair of scrolls during normal operation and a second position in which said orbiting scroll is separated from the other one of said pair of scrolls upon slowing down and any tendency for reverse operation and pressure equalization; centrifugal force produced solely by movement of said orbiting scroll and said slider block during normal operation tends to keep said orbiting scroll and said slider block in said first position; means for causing said orbiting scroll and said slider block to move along said flat surface from said first position to said second position and to separate said pair of scrolls during slowing down of said compressor before any reverse rotation occurs, establishing an unimpeded flow path through said compressor means and decreasing reversing torque caused by gas loads by reduction of orbit radius, said means for causing including said flat surface being oriented at an acute angle to a plane defined by said axis of rotation and an axis of rotation of said drive pin.
0. 10. A scroll compressor means including a pair of scrolls one of which being an orbiting scroll, a slider block and a crankshaft wherein said orbiting scroll has a hub with a bore which has an axis and which receives said slider block, and said crankshaft has an axis of rotation and a drive pin which is received in a bore in said slider block, one of said pin and said slider block having a flat surface normally engaged by the other one of said pin and said slider block, said bore in said slider block being larger than said pin and generally coaxial with said bore in said hub and said drive pin acting through said slider block to drive said orbiting scroll during normal operation and said orbiting scroll tending to act through said slider block to drive said drive pin and crankshaft during reverse operation and pressure equalization through said compressor means at shutdown, reverse rotation prevention means comprising:
said orbiting scroll and said slider block being movable with respect to said drive pin along said flat surface between a first position in which said orbiting scroll engages the other one of said pair of scrolls during normal operation and a second position in which said orbiting scroll is separated from the other one of said pair of scrolls upon slowing down and any tendency for reverse operation and pressure equalization; centrifugal force produced solely by movement of said orbiting scroll and said slider block during normal operation tends to keep said orbiting scroll and said slider block in said first position; means for causing said orbiting scroll and said slider block to move along said flat surface from said first position to said second position and to separate said pair of scrolls during slowing down of said compressor before any reverse rotation occurs, establishing an unimpeded flow path through said compressor means and decreasing reversing torque caused by gas loads by reduction of orbit radius; wherein said means for causing said orbiting scroll and slider block to move from said first to said second position includes spring means and further including said flat surface being oriented at an acute angle to a plane defined by said axis of rotation and an axis of rotation of said drive pin.
0. 2. The scroll compressor means of
0. 3. The scroll compressor means of
0. 4. The scroll compressor means of
0. 5. The scroll compressor means of
0. 6. The scroll compressor means of
0. 7. The scroll compressor means of
0. 8. The scroll compressor means of
0. 9. The scroll compressor means of
0. 15. The scroll compressor means of
0. 16. The scroll compressor means of
|
In
As best shown in
As illustrated in
Starting with the members in the position shown in
To achieve a great degree of torque reduction, it is advantageous to allow the orbiting scroll 12 to move radially inward as much as possible within limitations imposed by design. This can be accomplished by a combination of sizing the "D-shaped" recess 20-1 in slider block 20 and of sizing of the outer diameter of drive pin 30-1 and the positioning of drive pin 30-1 relative to crankshaft center C--C A--A. These modifications must be consistent with other design constraints. Of course, travel must not be great enough that orbit radius is too little to allow energizing the orbiting scroll 12 at startup.
The slider block/eccentric drive-type mechanism can be configured so that the inertia load causing wraps 12-1 and 14-1 to contact is opposed by both the radial gas load and another load, applied at eccentric barreled drive area 30-2, equal to Ftg tan θ, where Ftg is the tangential gas load and the angle θ is a design feature. Preferably, θ is of a value such that at a speed for which is desirable for wraps to separate, the friction load, that tends to prevent the wraps from separating, is counteracted. This design feature, the angle θ, is illustrated in
where
m is the combined mass of orbiting scroll 12 and slider block 20
Ro is the orbit radius in the fully energized position
ω is the rotational speed of the compressor/crankshaft at the onset of wrap separation
Ftg is the tangential gas force
Frg is the radial gas force
μ is the coefficient of friction between 20-2 and 30-2
Thus, in effect, the device of
The device of
The orientation of the barreled drive area 130-2 of drive pin 130-1, as defined by the angle θ, can have a substantially effect on compressor efficiency because it can affect whether the flanks of wraps 12-1 and 14-1 contact each other and seal effectively. AS discussed above, the same effect can be used to advantage during shutdown or power interruptions since separating the wraps 12-1 and 14-1, and keeping them separated, can prevent reverse rotation of orbiting scroll 12. However, flat orientations that are best for normal operation and for keeping the wraps 12-1 and 14-1 separated during shutdown are not necessarily the same, so a compromise between these two goals may be required.
Referring to
where Ro=orbit radius in fully energized position (with slider block center at X) Ro=distance from X to A and r=orbit radius when flank separation of some degree exists (slider block center at Y) (r=distance from Y to A)
Study of this equation shows that the angle α+θ between drive force, Fdrive, and tangential gas force, Ftg, varies as the slider block moves along the flat and, correspondingly, as scroll wrap separation is occurring.
Specifically, for cases where θ is greater than zero, (positive θ is defined in
This behavior only occurs for designs with θ>zero. As review of the equation above shows, when θ=zero, α+θ is equal to zero regardless of how much the slider block 20 moves during flank separation. Thus, conventional designs with θ=zero, as illustrated in
The significance of this behavior is that designs for which θ>zero realize a twofold benefit. First, a component of force tending to cause wrap separation is created. (This was explained previously). Second, a positive separation effect is achieved, since once separation begins the separating force increases in magnitude as separation progresses. Both of these benefits are useful for the purposes of this invention.
The above explanation applied to
Although preferred embodiments of the present invention have been illustrated and described, other changes will occur to those skilled in the art. It is therefore intended that the present invention is to be limited only by the scope of the appended claims.
Barito, Thomas R., Shoulders, Stephen L.
Patent | Priority | Assignee | Title |
10388416, | Oct 17 2013 | CLYDE UNION S A S | Motor-driven centrifugal pump for the primary circuit of small or medium-sized modular nuclear reactors |
Patent | Priority | Assignee | Title |
1780109, | |||
3884599, | |||
3924977, | |||
4045682, | May 06 1976 | Phase reversal protection system | |
4696630, | Sep 30 1983 | Kabushiki Kaisha Toshiba | Scroll compressor with a thrust reduction mechanism |
4764096, | May 30 1986 | Matsushita Electric Industrial Co., Ltd. | Scroll compressor with clearance between scroll wraps |
4820130, | Dec 14 1987 | AMERICAN STANDARD INTERNATIONAL INC | Temperature sensitive solenoid valve in a scroll compressor |
4877382, | Aug 22 1986 | Copeland Corporation | Scroll-type machine with axially compliant mounting |
4886435, | Mar 12 1987 | Matsushita Electric Industrial Co., Ltd. | Scroll compressor with intermittent oil supply passage |
4969801, | Nov 06 1989 | Ingersoll-Rand Company | Method and apparatus for shutting off a compressor when it rotates in reverse direction |
4990057, | May 03 1989 | Johnson Controls Technology Company | Electronic control for monitoring status of a compressor |
4998864, | Oct 10 1989 | Copeland Corporation | Scroll machine with reverse rotation protection |
5017107, | Nov 06 1989 | Carrier Corporation | Slider block radial compliance mechanism |
5290161, | Jun 02 1993 | Delphi Technologies, Inc | Control system for a clutchless scroll type fluid material handling machine |
5320507, | Oct 17 1991 | Copeland Corporation | Scroll machine with reverse rotation protection |
5433589, | Dec 27 1991 | Mitsubishi Denki Kabushiki Kaisha | Scroll-type compressor having decreased eccentricity upon reverse rotation |
5520524, | Oct 13 1993 | Nippondenso Co., Ltd.; Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Scroll-type compressor with reduced start-up orbiting radius |
5545019, | Nov 02 1992 | Copeland Corporation | Scroll compressor drive having a brake |
DE3317871, | |||
EP78148, | |||
EP468605, | |||
JP450489, | |||
JP5187366, | |||
JP5248371, | |||
JP5248372, | |||
JP5560684, | |||
JP61272481, | |||
JP6185476, | |||
JP6185477, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Dec 02 1998 | Carrier Corporation | (assignment on the face of the patent) | / |
Date | Maintenance Fee Events |
Sep 10 2007 | REM: Maintenance Fee Reminder Mailed. |
Feb 29 2008 | EXP: Patent Expired for Failure to Pay Maintenance Fees. |
Date | Maintenance Schedule |
Sep 10 2005 | 4 years fee payment window open |
Mar 10 2006 | 6 months grace period start (w surcharge) |
Sep 10 2006 | patent expiry (for year 4) |
Sep 10 2008 | 2 years to revive unintentionally abandoned end. (for year 4) |
Sep 10 2009 | 8 years fee payment window open |
Mar 10 2010 | 6 months grace period start (w surcharge) |
Sep 10 2010 | patent expiry (for year 8) |
Sep 10 2012 | 2 years to revive unintentionally abandoned end. (for year 8) |
Sep 10 2013 | 12 years fee payment window open |
Mar 10 2014 | 6 months grace period start (w surcharge) |
Sep 10 2014 | patent expiry (for year 12) |
Sep 10 2016 | 2 years to revive unintentionally abandoned end. (for year 12) |