SCROLL COMPRESSOR AND PROCESS FOR COMPRESSING A GASEOUS FLUID WITH THE SCROLL COMPRESSOR

Abstract

A scroll compressor for compressing a gaseous fluid, in particular a refrigerant. The scroll compressor exhibits a non-moving stator with at least one outlet and a moving orbiter, each with a base plate and a spiral-shaped wall that extends from the base plate. The base plates are arranged relative to one another in such a way that the walls interlock with one another and closed working chambers are created. The volumes and the positions of the working chambers are changed in reaction to a rotary movement of the orbiter here.

Claims

1.-16. (canceled)

17. A scroll compressor for compressing a gaseous fluid comprising: a non-moving stator with a base plate and a spiral-shaped wall that extends from the base plate; at least one outlet; and a moving orbiter with a base plate and a spiral-shaped wall that extends from the base plate, wherein the base plate of the stator and the base plate of the orbiter are arranged relative to one another in such a way that the wall of the stator and the wall of the orbiter interlock with one another and create closed working chambers, wherein volumes and positions of the working chambers are changed in reaction to a rotary movement of the orbiter, wherein the wall of the stator and the wall of the orbiter are configured in such a way that a first end chamber of the working chambers and a second end chamber of the working chambers of a compression path, as well as an intermediate chamber arranged between the first end chamber and the second end chamber at inner ends of the wall of the stator and the wall of the orbiter are formed in an area of the at least one outlet based on a rotation angle of the orbiter, and wherein at least one of the wall of the stator and the wall of the orbiter in an area of the inner ends is configured in such a way that a gap is created between the wall of the stator and the wall of the orbiter as a flow path from the intermediate chamber to at least one of the first end chamber and the second end chamber, wherein a degree of opening of the flow path is dependent on the rotation angle of the orbiter.

18. The scroll compressor according to claim 17, wherein the wall of the stator with the inner end on the wall of the orbiter and the wall of the orbiter with the inner end on the wall of the stator are arranged next to one another and create the sealed intermediate chamber based on the rotation angle of the orbiter.

19. The scroll compressor according to claim 17, wherein the gap is created, based on the rotation angle of the orbiter, between the wall of the stator and the wall of the orbiter as a flow path from the intermediate chamber to the first end chamber and/or the gap is created as a flow path from the intermediate chamber to the second end chamber, wherein the degree of opening of each of the flow paths is dependent on the rotation angle of the orbiter.

20. The scroll compressor according to claim 17, wherein a gap created between the wall of the stator and the wall of the orbiter as a flow path from the first end chamber to the second end chamber based on the rotation angle of the orbiter, wherein a degree of opening of the flow path from the first end chamber to the second end chamber is dependent on the rotation angle of the orbiter.

21. The scroll compressor according to claim 17, wherein the at least one of the wall of the stator and the wall of the orbiter is constructed with a wall thickness reduced in the area of the inner ends between two sections in order to increase an original volume of the intermediate chamber.

22. The scroll compressor according to claim 21, wherein the at least one of the wall of the stator and the wall of the orbiter is constructed in such a way that the wall thickness of the at least one of the wall of the stator and the wall of the orbiter decreases continuously from a first one of the two sections moving towards a second one of the two sections and is then increased in an area of the second one of the two sections to an original thickness at the second one of the two sections.

23. The scroll compressor according to claim 17, wherein the at least one of the wall of the stator and the wall of the orbiter exhibits a constant wall thickness across a height of the at least one of the wall of the stator and the wall of the orbiter.

24. The scroll compressor according to claim 17, wherein the wall of the orbiter is constructed in such a way in the area of the inner end that a gap is created between the wall of the stator and the wall of the orbiter as a flow path from the intermediate chamber to the at least one of the first end chamber and the second end chamber.

25. The scroll compressor according to claim 17, wherein the wall of the stator is constructed in such a way in the area of the inner end that a gap is created between the wall of the stator and the wall of the orbiter as a flow path from the intermediate chamber to the at least one of the first end chamber and the second end chamber.

26. A process for compressing the gaseous fluid using the scroll compressor according to claim 17, wherein in a certain range of the rotation angle of the orbiter with an arrangement of the stator and the orbiter a gap is opened between the wall of the stator and the wall of the orbiter as a flow path from the intermediate chamber to the at least one of the first end chamber and the second end chamber, whose degree of opening is dependent on the rotation angle of the orbiter, wherein the intermediate chamber is closed at a rotation angle of 0° with the arrangement of the stator and orbiter.

27. The process according to claim 26, wherein the flow path from the intermediate chamber to the at least one of the first end chamber and the second end chamber is opened in the rotation angle range of greater than 0° up to 60°.

28. The process according to claim 26, wherein an open gap is created between the intermediate chamber and one of the first end chamber and the second end chamber with an arrangement of the stator and the orbiter at the rotation angle of the orbiter in a range around 20°, wherein the flow path between the intermediate chamber and the one of the first end chamber and the second end chamber exhibits a degree of opening of around 20%.

29. The process according to claim 26, wherein an open gap is created between the intermediate chamber and the first end chamber, as well as between the intermediate chamber and the second end chamber, with an arrangement of the stator and the orbiter at the rotation angle of the orbiter in a range around 30°.

30. The process according to claim 29, wherein a flow path between the intermediate chamber and one of the first end chamber and the second end chamber exhibits a degree of opening of around 40%.

31. The process according to claim 26, wherein a gap is created between the intermediate chamber and the first end chamber, as well as between the intermediate chamber and the second end chamber with an arrangement of the stator and the orbiter at the rotation angle of the orbiter in a range around 60° in such a way that compressed fluid flows between the first end chamber and the second end chamber.

32. The process according to claim 26, wherein a flow path between the first end chamber and the second end chamber is continuously opened at the rotation angle within a range greater than 30° and fully open at the rotation angle of around 115° with an arrangement of the stator and the orbiter.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0036] Further details, features and benefits of embodiments of the invention result from the following description of specimen embodiments with reference to the accompanying drawings. These display the following:

[0037] FIGS. 1A and 1B: A scroll compressor as a device for compressing a gaseous fluid using a compression mechanism in a lateral sectional view, as well as a detailed view of a plan view of the compression mechanism,

[0038] FIGS. 2A to 2C: A spiral-shaped wall of the compression mechanism in a plan view, as well as a detailed view of an inner end of the spiral-shaped wall,

[0039] FIGS. 3A to 3H: Gap between the inner ends of the spiral-shaped walls of the compression mechanism based on a rotation angle of an orbiter relative to a stator and comparison of a conventional wall with a wall according to the invention, each in a plan view, as well as

[0040] FIG. 4A: A diagram of the degree of opening of a flow path between two end chambers based on the rotation angle of the orbiter relative to the stator, as well as

[0041] FIG. 4B: A diagram of the degree of opening of a flow path between an intermediate chamber and an end chamber based on the rotation angle of the orbiter relative to the stator.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0042] FIG. 1A shows a lateral sectional view of a scroll compressor 1 as a device for compressing a gaseous fluid using a compression mechanism.

[0043] The scroll compressor 1 exhibits a housing 2, a non-moving, fixed stator 3 with a disk-shaped base plate 3a and a spiral-shaped wall 3b that extends from one side of the base plate 3a, as well as a moving orbiter 4 with a disk-shaped base plate 4a and a spiral-shaped wall 4b that extends from the base plate 4a. The stator 3 and orbiter 4 work together and are, in particular, arranged relative to one another with the base plates 3a, 4a in such a way that the wall 3b of the stator 3 and the wall 4b of the orbiter 4 interlock with one another.

[0044] The orbiter 4, also classed as a moving scroll 4, is moved on a circular path using an eccentric drive and relative to the stator 3, also classed as a fixed scroll 3. The spiral-shaped wall 4b revolves around the stationary spiral-shaped wall 3b. During the relative movement of the scrolls 3, 4 to one another, the walls 3b, 4b touch one another in multiple locations and form multiple consecutive, sealed working chambers 5, 5-0, 5-1, 5-2 between the walls 3b, 4b and the base plates 3a, 4a, wherein the working chambers arranged next one another 5, 5-0, 5-1, 5-2 (neighboring chambers) display different volumes.

[0045] The volumes and the positions of the working chambers 5, 5-0, 5-1, 5-2 change in reaction to the movement of the orbiter 4 relative to the stator 3. The size of the working chambers 5, 5-0, 5-1, 5-2 is reduced due to the counter-rotational movement of the two interlocking, spiral-shaped walls 3b, 4b. The volumes of the working chambers 5, 5-0, 5-1, 5-2 arranged towards the center of the spiral-shaped walls 3b, 4b, which are also classed as scroll walls, become smaller. Here, a gaseous fluid enclosed inside the working chambers is compressed and then released from the compression mechanism through an outlet 6 from a first end chamber 5-1 of a first compression path of the scroll compressor 1, as well as from a second end chamber 5-2 of a second compression path of the scroll compressor 1. The gaseous fluid to be compressed, in particular a refrigerant, is drawn in, compressed inside the compression mechanism and then released via an outlet.

[0046] The eccentric drive (not shown) exhibits a drive shaft that rotates around a rotary axis and is supported by bearings on the housing 2. The orbiter 4 is eccentrically connected to the drive shaft via an intermediate element. This means that the axes of the orbiter 4 and the drive shaft are arranged with an offset from one another. The orbiter 4 is supported via another bearing on the intermediate element.

[0047] FIG. 1B shows a detailed view A of a plan view of the compression mechanism from FIG. 1a in the area of the intermediate chamber 5-0, the end chambers 5-1, 5-2, as well as the outlet 6. FIGS. 2A and 2B show the spiral-shaped wall 4b of the orbiter 4 as a single element in a schematic plan view, as well as a detailed view B of an inner end 4c of the spiral-shaped wall 4b. FIG. 2C shows an inner end 4c of an embodiment of a spiral-shaped wall 4b of the moving scroll 4. The outlet 6 is constructed as a sealable passage opening in the base plate 3a of the stator 3 and, just like the wall 3b of the stator 3, is therefore non-moving—also relative to the wall 3b.

[0048] As a result of the movement of the orbiter 4 along the circular path and relative to the stator 3, the spiral-shaped wall 4b revolves around the stationary spiral-shaped wall 3b. As per FIG. 1B, the walls 3b, 4b of the scrolls 3, 4 are each arranged on internal sides in the area of inner ends 3c, 4c, aligned with one another and in contact with one another. Here, the wall 3b of the fixed scroll 3 is in contact with the inner end 3c on the wall 4b of the moving scroll 4, while the wall 4b of the moving scroll 4 is in contact with the inner end 4c on the wall 3b of the fixed scroll 3, thereby sealing off the intermediate chamber 5-0.

[0049] Consequently, the intermediate chamber 5-0 is limited on the one side by the wall 3b of the stator 3 and on the other side by the wall 4b of the orbiter 4. The walls 3b, 4b are arranged such that they are in contact with one another in two sections of the inner end 4c of the wall 4b.

[0050] In the area of the inner end 4c of the wall 4b of the orbiter 4, the wall 4b between two sections 7, 8 is constructed with a reduced wall thickness in comparison with a wall 4b′ of an orbiter as per the state of the art. The wall thicknesses of the walls 4b, 4b′ gradually increases, starting from the first section 7 and moving towards the second section 8. It is then reduced quite sharply in the area of the second section 8, in particular in comparison with the gradual increase. The contour of the wall 4b of the orbiter 4 differs from the wall 4b′ of a conventional orbiter between sections 7, 8. Otherwise, the contours of the walls 4b, 4b′ are primarily constructed identically.

[0051] The arrangement of the sections 7, 8 of the wall 4b is fixed in each case in such a way that the efficiency of the process of compressing the fluid remains unchanged. Based on a simulation of the movement of the orbiter 4, taking into account the outlet 6 constructed on the stator 3, in particular taking into account the position and size of the outlet 6, a sealing line is determined between the walls 3b, 4b of the two scrolls 3, 4 in such a way that the intermediate chamber 5-0 is optimally sealed as the final compression chamber, which is necessary for a high efficiency of the process of compressing the fluid, particularly at high pressures. The second section 8 is, in particular, arranged precisely in order to avoid any loss of efficiency during compression.

[0052] The radius of the inner side of the wall 4b of the orbiter 4 according to the invention is greater than the radius of the inner side of the wall 4b′ of the orbiter known from the state of the art, meaning that the volume of the intermediate chamber 5-0 of the compression mechanism of the scroll compressor 1 according to the invention is greater than the volume of an intermediate chamber of the compression mechanism of a conventional scroll compressor. The base plates 3a, 4a of the compression mechanisms that limit the volume of the intermediate chambers 5-0 are also identical.

[0053] The area of the inner end 4c of the wall 4b of the orbiter 4, in particular the inner side of the inner end 4c, is preferably defined as a so-called “spline” with more than two radiuses, with freely defined mathematical functions or via reference points and modified.

[0054] The contours of the wall 4b of the orbiter 4 are identical in the area of a first face connected to the base plate 4a and a second, free face that is aligned in the axial direction, as well as distally towards the base plate 4a. The faces of the wall 4b, each of which is arranged on a plane defined vertically to the axial direction, are consequently the same and also arranged at even spacings from one another. The distance between the faces is classed as the height of the wall 4b. The expansion of the wall in the axial direction is therefore viewed as the height of the wall 4b. The contour of the wall 4b is constant over the entire height of the wall 4b.

[0055] The wall 4b of the orbiter 4, which extends from the first face, itself aligned towards the base plate 4a of the orbiter 4, to the second face, which is aligned towards the base plate 3a of the stator 3, can be manufactured in a combined process with the other scroll geometry or also within a step-by-step process. Manufacture of the moving scroll 4 can then be performed using a casting tool or cutting tool and forming the base plate 4a with the wall 4b in one step or within a two-step or multi-step process in separate steps. The contour of the wall 4b can also be produced using high-precision turning processes, milling processes or combined turning/milling processes, as well as during rough or precision grinding of the scrolls 4.

[0056] Compared to a conventional scroll compressor, the wall 4b of the orbiter 4 of the scroll compressor 1 according to the invention is modified in such a way that in certain arrangements of the scrolls 3, 4 to one another, in particular in specific ranges of a rotation angle in which a closed intermediate chamber 5-0 is conventionally constructed, a gap between the walls 3b, 4b of the scrolls 3, 4 is secured, whose degree of opening is based on the rotation angle of the orbiter 4. The associated degree of opening of a flow path that is dependent on the rotation angle of the orbiter 4 due to the gap can adapted optimally to the corresponding application in each case, in particular the pressure levels in place, the wrap angles of the compression paths, as well as opening geometries within the fixed scroll 3, in particular to avoid any overpressure of the compressed fluid inside the intermediate chamber 5 or to minimize this pressure or secure the most even pressure equalization possible between the two end chambers 5-1, 5-2 of the compression paths of the scroll compressor 1, also to avoid any acceleration of the orbiter 4. Consequently, the space between the scrolls 3, 4 is changed, in particular increased, on the basis of the rotation angle of the orbiter 4 using the variable degree of opening of the gap in order to guarantee a flow for equalization of the pressures of the fluid inside the end chambers 5-1, 5-2 and thereby an equalization flow between the two end chambers 5-1, 5-2. The variable degree of opening of the gap that is based on the rotation angle results from the contours of the spiral-shaped walls 3b, 4b of the scrolls 3, 4.

[0057] With the objective of avoiding pressure spikes due to trapped fluid, as well as avoiding sudden pressure equalization processes, the rotation angle-based contour of the orbiter 4 is calculated, for example using CFD (computational fluid dynamics) simulations. Unchanged contours of the walls 3b, 4b of the scrolls 3, 4 are used as the starting point for calculation here. During the calculations, at least one of the contours of the walls 3b, 4b of the scrolls 3, 4 is changed in such a way over an unchanged contour of the walls 3b, 4b of the scrolls 3, 4 that larger gaps between the walls 3b, 4b of the scrolls 3, 4 are created during the orbiting movement of the orbiter 4.

[0058] The arrangement of the calculated contour of the wall 3b, 4b is then adjusted, taking into account boundary conditions of manufacturing, such as minimum radiuses that can be produced and possible cutting paths of the tool used.

[0059] The final construction of the contour of the wall 3b, 4b, for example as per FIG. 2C, in particular of the inner end 4c of the wall 4b of the orbiter 4 with the various radiuses R1, R2, R3, is then based on experimental tests on compressors, taking into account the efficiency of the process of compressing the fluid and the NVH behavior of the compressor. The contour of the wall 4b is changed between the two sections 7, 8 relative to a wall 4b′ of an orbiter as per the state of the art. In each case, the contour corresponds to the unchanged original contour UK up to the sections 7, 8. A transition contour UK is also formed in the area of the second section 8.

[0060] FIGS. 3A to 3H use a plan view to show an open or closed gap between the inner ends 3c, 4c of the spiral-shaped walls 3b, 4b of the compression mechanism based on the rotation angle of the orbiter 4 relative to the stator 3 and a comparison of a conventional wall 4b′ with a wall of the orbiter according to the invention 4b. FIG. 4A also shows a diagram of the degree of opening of a flow path between the two end chambers 5-1, 5-2 based on the rotation angle of the orbiter 4 relative to the stator 3, while FIG. 4B shows a diagram of the degree of opening of a flow path between the intermediate chamber 5-0 and the first end chamber 5-1 based on the rotation angle of the orbiter 4 relative to the stator 3.

[0061] Up to an arrangement of stator 3 and orbiter 4 at a rotation angle of 0° as per FIG. 3A, the scroll compressors 1 display identical compression behavior with a wall according to the invention 4b and a conventional wall 4b′. In each case here, both the first section 7, as a connection between the intermediate chamber 5-0 and the first end chamber 5-1 of the first compression path, and the second section 8, as a connection between the intermediate chamber 5-0 and the second end chamber 5-2 of the second compression paths, are closed. The sections 7, 8 between the walls 3b, 4b, 4b′ of the scrolls 3, 4 are sealed off, so that the degrees of opening of the respective flow paths as per FIGS. 4A and 4B are zero.

[0062] With an arrangement of stator 3 and orbiter 4 at a rotation angle of 20° as per FIG. 3B and construction of the wall according to the invention 4b, a gap is open in the area of the first section 7 between the intermediate chamber 5-0 and the first end chamber 5-1 in comparison with the conventional wall 4b′, so that compressed fluid flows out of the intermediate chamber 5-0 and into the first end chamber 5-1 and thereby reduces or avoids overpressure in the intermediate chamber 5-0. As per FIG. 4B, the flow path between the intermediate chamber 5-0 and the first end chamber 5-1 exhibits a degree of opening of 20%. With construction of the conventional wall 4b′, the first section 7, as a connection between the intermediate chamber 5-0 and the first end chamber 5-1, is closed.

[0063] The second section 8, as a connection between the intermediate chamber 5-0 and the second end chamber 5-2, is closed regardless of the construction of the wall 4b, 4b′ of the orbiter 4, so that the flow paths between the end chambers 5-1, 5-2 are also closed. Since, with construction of the conventional wall 4b′, both the first section 7 and the second section 8 are closed as connections between the intermediate chamber 5-0 and one of the end chambers 5-1, 5-2, the risk of excessive overpressure inside the intermediate chamber 5-0 is very high.

[0064] With an arrangement of stator 3 and orbiter 4 at a rotation angle of 30° as per FIG. 3C and construction of the wall according to the invention 4b, a gap is formed or a flow path opened both in the area of the first section 7 between the intermediate chamber 5-0 and the first end chamber 5-1 and in the area of the second section 8 between the intermediate chamber 5-0 and the second end chamber 5-2 in comparison with the conventional wall 4b′, so that compressed fluid flows out of the intermediate chamber 5-0 and into the end chambers 5-1, 5-2 and thereby reduces or avoids overpressure in the intermediate chamber 5-0. As per FIG. 4B, the flow path between the intermediate chamber 5-0 and the first end chamber 5-1 exhibits a degree of opening of 40%. Due to the low degrees of opening of the gaps in the area of the sections 7, 8 and the release of the fluid from the intermediate chamber 5-0 into the respective end chambers 5-1, 5-2 due to the greater pressure of the fluid inside the intermediate chamber 5-0, no fluid flows between the end chambers 5-1, 5-2 themselves, so that the degree of opening of the flow path between the end chambers 5-1, 5-2 as per FIG. 4A is zero.

[0065] With the construction of the conventional wall 4b′, both the first section 7, as a connection between the intermediate chamber 5-0 and the first end chamber 5-1, and the second section 8, as a connection between the intermediate chamber 5-0 and the second end chamber 5-2, are closed, meaning that the flow path between the end chambers 5-1, 5-2 is consequently also closed and additionally that the risk of excessive overpressure inside the intermediate chamber 5-remains very high.

[0066] With an arrangement of stator 3 and orbiter 4 at a rotation angle of 60° as per FIG. 3D and construction of the wall according to the invention 4b, a gap is opened both in the area of the first section 7 between the intermediate chamber 5-0 and the first end chamber 5-1 and in the area of the second section 8 between the intermediate chamber 5-0 and the second end chamber 5-2 in comparison with the conventional wall 4b′ in such a way that compressed fluid flows between the end chambers 5-1, 5-2 and that an early pressure equalization is thereby performed in both end chambers 5-1, 5-2. The intermediate chamber 5-0 is a complete component of the flow path between the end chambers 5-1, 5-2, so that the degree of opening between the intermediate chamber 5-0 and the first end chamber 5-1 as per FIG. 4B is zero. As per FIG. 4A, the flow path between the end chambers 5-1, 5-2 exhibits a degree of opening of around 10%.

[0067] With the construction of the conventional wall 4b′, both the first section 7, as a connection between the intermediate chamber 5-0 and the first end chamber 5-1, and the second section 8, as a connection between the intermediate chamber 5-0 and the second end chamber 5-2, are closed, meaning that the flow path between the end chambers 5-1, 5-2 is consequently also closed and additionally that the risk of excessive overpressure inside the intermediate chamber 5-remains very high. The intermediate chamber 5-0 is also reduced to a minimum volume.

[0068] With an arrangement of stator 3 and orbiter 4 at rotation angles in excess of 60° as per FIGS. 3E to 3H, particularly at rotation angles of around 85°, 100°, 105° and 115°, and construction of the wall according to the invention 4b, the flow path between the end chambers 5-1, 5-2 remains continuously open, meaning that the degree of opening is around 30%, 52%, 80% and 100%. At a rotation angle of 115°, the flow path is completely open. The pressure equalization in both end chambers 5-1, 5-2 is performed continuously and evenly. Due to the lack of an intermediate chamber 5-0, the degree of opening of the flow path between the intermediate chamber 5-0 and the first end chamber 5-1 as per FIG. 4B remains zero.

[0069] With the construction of the conventional wall 4b′ and an arrangement of stator 3 and orbiter 4 at a rotation angle of around 85° as per FIG. 3E, the sections 7, 8, as a connection between the end chambers 5-1, 5-2, and consequently also the flow path between the end chambers 5-1, 5-2, remain closed. It is not possible to perform pressure equalization between the end chambers 5-1, 5-2. Only with an arrangement of stator 3 and orbiter 4 at a rotation angle of around 100° as per FIG. 3F is a gap opened as a flow path between the end chambers 5-1, 5-2, meaning that a process of pressure equalization between the end chambers 5-1, 5-2 starts. As per FIG. 4A, the degree of opening of the flow path is around 5%. With an arrangement of stator 3 and orbiter 4 at rotation angles in excess of 100° as per FIGS. 3G and 3H, particularly at rotation angles of around 105° and 115°, the flow path between the end chambers 5-1, 5-2 is opened further, meaning that the degree of opening is then around 40% and 80%. Only at a rotation angle of 120° is the flow path completely open.

[0070] When comparing an orbiter 4 with a wall according to the invention 4b against an orbiter with a conventional wall 4b′, in summary it can be stated that the flow path between the end chambers 5-1, 5-2 is already opened evenly, starting at a rotation angle in the range from 30° to 40°, with the inventive embodiment, so that even and continuous pressure equalization takes place between the end chambers 5-1, 5-2. On an orbiter with conventional wall 4b′, the flow path between the end chambers 5-1, 5-2 is only opened at a rotation angle of around 100°. Since the flow paths are each completely open at a rotation angle of around 115° to 120°, the flow path on the orbiter with conventional wall 4b′ is opened abruptly and in a short time period, meaning that the pressure equalization also cannot take place evenly or continuously.

[0071] In addition to this, an overpressure inside the intermediate chamber 5-0 is reduced or avoided by the opening of a flow path between the intermediate chamber 5-0 and an end chamber 5-1 on the orbiter 4 with a wall according to the invention 4b. A flow path of this kind is not opened with an orbiter exhibiting a conventional wall 4b′, meaning that the overpressure.