Abstract
A thrust plate for use in a scroll compressor is described. The thrust plate comprises a disk-shaped body defining a plane and having a first side and a second side, wherein the second side opposes the first side, at least one protrusion extending from the first side, and at least one recess located at the second side, wherein the at least one protrusion and the at least one recess overlap at least partially in a direction perpendicular to the plane. Further, a system is described, wherein the system comprises a thrust plate with at least one protrusion and an orbiting scroll plate with at least one recess, wherein the at least one protrusion and the at least one recess overlap. Also, a scroll compressor having either a corresponding thrust plate or a corresponding system is described.
Claims
1. A thrust plate for use in a scroll compressor, the thrust plate comprising: a disk-shaped body defining a plane and having a first side and a second side, wherein the second side opposes the first side; at least one protrusion extending from the first side; and at least one recess located at the second side; wherein the at least one protrusion and the at least one recess overlap at least partially in a direction perpendicular to the plane.
2. The thrust plate according to claim 1, wherein the disk-shaped body comprises a plurality of holes, which extend from a surface of the first side to a surface of the second side and which are configured to receive pins of an Oldham coupling.
3. The thrust plate according to claim 1, wherein the disk-shaped body comprises an aperture, which extends from a surface of the first side to a surface of the second side and which is configured to receive a portion of a crankshaft and/or a portion of an orbiting scroll plate.
4. The thrust plate according to claim 1, wherein the at least one recess is located at a surface of the second side.
5. The thrust plate according to claim 1, wherein the at least one recess is located beneath a surface of the second side.
6. The thrust plate according to claim 1, wherein the at least one protrusion overlaps entirely with the at least one recess.
7. The thrust plate according to claim 6, wherein at least a portion of the at least one recess does not overlap with the at least one protrusion.
8. The thrust plate according to claim 1, wherein the first side comprises two or more protrusions and wherein each of the two or more protrusions overlaps entirely with at least a portion of the at least one recess.
9. The thrust plate according to claim 1, wherein the at least one protrusion and the at least one recess form first and second patterns, respectively.
10. The thrust plate according to claim 9, wherein the first pattern overlaps entirely with the second pattern, but wherein the at least one recess extends outwardly in every in-plane direction of the plane for a distance of 1 to 2 mm.
11. The thrust plate according to claim 1, wherein the at least one protrusion has an annular shape and wherein the at least one recess has an annular shape.
12. The thrust plate according to claim 11, wherein the first side comprises two or more protrusions, wherein the two or more protrusions form concentric rings, and/or wherein the second side comprises two or more recesses, wherein the two or more protrusions form concentric rings.
13. The thrust plate according to claim 1, wherein each of the at least one protrusion is formed by a bar, which extend radially from a center of the disk-shaped body and wherein each of the at least one recess is formed by a groove, which extend radially from the center of the disk-shaped body, the number of the plurality of bars and the number of the plurality of grooves being the same.
14. A system comprising: a thrust plate comprising: a disk-shaped body defining a plane and having a first side and a second side, wherein the second side opposes the first side, and at least one protrusion extending from the first side; and an orbiting scroll plate having a base plate with a frontside and a backside, wherein the orbiting scroll plate comprises at least one recess located at its backside; wherein the backside of the orbiting scroll plate at least partially abuts at least a portion of the second side of the thrust plate, and wherein the at least one protrusion and the at least one recess overlap at least partially in a direction perpendicular to the plane.
15. A scroll compressor comprising: either a thrust plate according to claim 1 and an orbiting scroll plate or a system of an orbiting scroll plate and a thrust plate according to claim 14.
Description
DRAWINGS
[0047] In the drawings, like reference characters generally refer to the same parts throughout the different drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
[0048] In the following description, various embodiments of the invention are described with reference to the following drawings, in which:
[0049] FIG. 1 shows a cross-sectional view of an exemplary scroll compressor in which the current invention may be exercised.
[0050] FIG. 2 shows an exploded view of the scroll plates, the thrust plate, the Oldham coupling, and an exemplary portion of the frame of the scroll compressor of FIG. 1.
[0051] FIGS. 3a, 3b show cross-sectional views of a thrust plate disposed between a frame and an orbiting scroll plate, wherein the forces caused by high fluid pressure during compression, which act on the orbiting scroll plate, are illustrated. Thereby, FIG. 3a illustrates the forces pushing the orbiting scroll plate towards the thrust plate and FIG. 3b illustrates wobbling or tilting caused by motion of the orbiting scroll plate.
[0052] FIGS. 4a, 4b show (a) a perspective view of an exemplary embodiment of the thrust plate according to the current invention and (b) a cross-sectional view along line A-A of FIG. 4a.
[0053] FIGS. 5a, 5b show (a) a bottom view of exemplary protrusions at a first side of a thrust plate according to one embodiment of the current invention and (b) an overlap of the protrusions at the first side and the recesses at the second side. In this embodiment, the protrusions and the recesses form an exemplary pattern.
[0054] FIGS. 6a-c show schematics of the overlap of a protrusion and a recess in a direction perpendicular to the plane defined by the disk-shaped body of the thrust plate, wherein (a) illustrates a protrusion, which overlaps entirely with a recess, while the recess itself is larger, (b) illustrates a protrusion and a recess of the same size and (c) illustrates a recess overlapping entirely with a protrusion, while the protrusion itself is larger.
[0055] FIGS. 7a, 7b show (a) a bottom view of an exemplary annular protrusion at a first side of a thrust plate according to a further embodiment of the current invention and (b) an overlap of the protrusions at the first side and the recesses at the second side. In this embodiment, the protrusions and the recesses form concentric rings.
[0056] FIGS. 8a, 8b show (a) a bottom view of exemplary annular protrusions at a first side of a thrust plate according to a further embodiment of the current invention and (b) an overlap of the protrusions at the first side and the recesses at the second side. In this embodiment, the protrusions and the recesses form concentric rings at the edges of the thrust plate.
[0057] FIGS. 9a, 9b show (a) a bottom view of exemplary protrusions at a first side of a thrust plate according to a further embodiment of the current invention and (b) an overlap of the protrusions at the first side and the recesses at the second side. In this embodiment, the protrusions and the recesses extend radially from a center of the surface of the respective side of the thrust plate.
[0058] FIG. 10 shows a cross-sectional view of a thrust plate according to a further embodiment of the current invention, wherein the recess of the second side is located beneath the surface of the second side.
[0059] FIGS. 11a-d show perspective views of (a) an orbiting scroll plate and (b), (c) thrust plates according to a further embodiment of the current invention as well as (d) an overlap of the protrusions and the recesses.
DETAILED DESCRIPTION
[0060] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced.
[0061] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs.
[0062] FIG. 1 shows a cross-sectional view of an exemplary scroll compressor in which the current invention may be exercised.
[0063] As depicted in FIG. 1, the scroll compressor 100 comprises a case 110, a suction port 160 for receiving fluid (e.g. a refrigerant) from a cycle (e.g. a refrigeration cycle), a scroll set 120, 130 for compressing the fluid and a discharge port 170 for discharging the compressed fluid and providing it back to the cycle. The scroll set 120, 130 comprises a stationary scroll plate 120, and an orbiting scroll plate 130. The stationary scroll plate 120 has an opening in its center, which is connected to a high pressure side of the scroll compressor. The opening of the stationary scroll plate may be connected to the high pressure side via a valve, for example a check valve.
[0064] The orbiting scroll plate 130 may be driven by a motor 180. The motor 180 drives a crankshaft 185, which causes a rotational motion of the crankshaft 185. The crankshaft 185 transfers its rotational motion to an orbiting motion of the orbiting scroll plate 130. This is achieved by providing the crankshaft 185 with a first end, which engages a slider block, which is placed in an aperture at the backside of the orbiting scroll plate 130. The slider block slides within the aperture, which avoids a rotation of the orbiting scroll plate 130. However, if the first end of the crankshaft 185 is offset to the rotation axis of the crankshaft 185, the orbiting scroll plate 130 will still be moved, but only in an orbiting path relatively to the stationary scroll plate 120.
[0065] In order to further avoid rotational motion of the orbiting scroll plate 130, an Oldham coupling 155 is provided, which engages the orbiting scroll plate 130. The Oldham coupling 155 has pins, which engage notches in the orbiting scroll plate 130.
[0066] The scroll compressor comprises a thrust plate 140, which is disposed between the backside of the orbiting scroll plate 130 and a frame 150, which supports the scroll set 120, 130. The thrust plate 140 comprises one or more protrusions and one or more recesses on corresponding locations of its opposing sides as will be described in more detail with respect to the following drawings. The Oldham coupling 155 is disposed behind the thrust plate 140 in clearances around the one or more protrusions of the thrust plate 140.
[0067] Additionally, the scroll compressor 100 depicted in FIG. 1 comprises a lubricant supply 190, which is connected to the crankshaft 185. Thereby, it is ensured that lubricant can be provided to the moving components of the scroll compressor 100, which reduces wear.
[0068] FIG. 2 shows an exploded view of the scroll plates 120, 130, the thrust plate 140, the Oldham coupling 155, and an exemplary portion of the frame 150 of the scroll compressor wo depicted in FIG. 1. From top to bottom of FIG. 2 the stationary scroll plate 120, the orbiting scroll plate 130, the thrust plate 140, the Oldham coupling 155 and a portion of the supporting frame 150 are shown. Stacking said components together in this order creates the assembly depicted in abovementioned FIG. 1.
[0069] FIGS. 3a, 3b show cross-sectional views of a thrust plate 140′ disposed between a frame 150 and an orbiting scroll plate 130, wherein the forces caused by high fluid pressure during compression, which act on the orbiting scroll plate 130 are illustrated. The thrust plate 140′ depicted in FIGS. 3a, 3b is a disk without protrusions or recesses. Such a thrust plate 140′ provides for a thrust surface, which can distribute the load experienced by the motion of the orbiting scroll plate. However, the disk-shaped thrust plate 140′ is sturdy and provides a hard contact between the orbiting scroll plate 130 and the supporting frame 150.
[0070] As is depicted in FIG. 3a, the fluid compressed at a high pressure creates a force F1, which pushes the orbiting scroll 130 away from the stationary scroll plate, i.e. downwards with respect to the orientation shown in FIG. 3a (see arrows in FIG. 3a). This presses the thrust plate 140′ against the supporting frame 150. Because of the solid structure of the thrust plate 140′, the thrust plate 140′ is sturdy and provides for hard contact, as is depicted by line A-B in FIG. 3a. Such a hard contact results in high contact stress and affects the lifetime of the compressor negatively.
[0071] Furthermore, upon motion of the orbiting scroll plate, tilting forces act on the orbiting scroll plate 130, which result in squeezing of the thrust plate 140′. However, because of the hard contact, the thrust plate 140′ cannot be deformed, which increases the wear and contact stress. This behavior is depicted in FIG. 3b. The crankshaft engages the aperture 134 at the backside of the orbiting scroll plate 130. When the crankshaft rotates, a force is applied to the boundary of the aperture 134, thereby pushing the orbiting scroll plate to the side, as is illustrated by force F2 in FIG. 3b. The orbiting motion of the orbiting scroll plate 130 caused by force F2 compresses the fluid within the compression chamber formed between the spiral wrap 132 of the orbiting scroll plate 130. Because the compression results in increased pressure, the pressure causes force F.sub.3, which is directed against the orbiting motion. Since force F2 acts on the backside of the orbiting scroll plate 130 and force F3 acts on the frontside of the orbiting scroll plate 130, there is an offset between these forces, which results in wobbling or tilting of the orbiting scroll plate as is illustrated in FIG. 3b. The person skilled in the art will appreciate that the tilt illustrated in FIG. 3b is shown exaggerated for illustrative purposes. As a result of wobbling or tilting, additional stress is applied onto the thrust plate 140′ locally. In the illustrative example depicted in FIG. 3b, forces F2 and F3 cause a tilt of the orbiting scroll plate 130 towards the left-hand side of the thrust plate 140′, thereby causing local squeeze at point C. Using a thrust plate with recess and protrusion according to the current invention reduces the stiffness of the thrust plate and thereby improves the adaptability of the thrust plate to a wobbling or tilting orbiting scroll plate, thereby reducing wear and improving the durability of the scroll compressor.
[0072] FIGS. 4a, 4b show (a) a perspective view of an exemplary embodiment of the thrust plate 140 according to the current invention and (b) a cross-sectional view along line A-A of FIG. 4a.
[0073] The thrust plate 140 comprises a disk-shaped body, which defines a plane and has a first side 250 and a second side 200. The plane may correspond to the dashed line illustrated in FIG. 4b, which separates the first and second sides. Protrusions 270 are formed at the first side 250 of the thrust plate 140, which are configured to contact the supporting frame, and recesses 220 are formed at the second side 200 of the thrust plate 140, wherein the second side 250 is configured to contact the backside of the orbiting scroll plate. The at least one protrusion 270 and the at least one recess 220 overlap at least partially in a direction perpendicular to the plane. Because of the overlap of the recesses 220 and the protrusions 270, any location of hard contact (as shown above with respect to FIG. 3a) is avoided. This allows for reducing the sturdiness and stiffness of the thrust plate 140 and enables a slight deformation of the thrust plate 140, which reduces the wear and contact stress.
[0074] FIG. 4b illustrates the terms first side 250 and second side 200. The dashed line is shown to identify the first side 250 below the dashed line and the second side 200 above the dashed line. Accordingly, said terms are not limited to a surface, but rather refer to the respective surface and an adjacent portion of the disk-shaped body below the surface. In the example depicted in FIG. 4b, the first side 250 may also be referred to as bottom side and the illustrated protrusion 270 extends from the surface 26o of the first side 250 downwardly. The second side 200 may also be referred to as top side and the illustrated recess 220 is located at the surface 240 of the second side 200. As can be seen in FIG. 4b, the contact surface for contact between the thrust plate 140 and the backside of the orbiting scroll plate does not overlap with the contact between the protrusions of the thrust plate and the supporting frame.
[0075] As the disk-shaped body of the thrust plate defines a plane, a cross-section identified by the dashed line may be an example of a location and course of such a plane. The plane may be parallel to the surface 240 of the second side of the thrust plate as is depicted in FIG. 4b. However, the surface 240 of the second side 200 may also represent the plane defined by the disk-shaped body. Similarly, the plane may also be defined by the surface of the 260 of the first side 250. Further, any plane parallel to any of the aforementioned surfaces or the cross-section identified by the dashed line of FIG. 4b may represent the plane. The person skilled in the art will appreciate that the plane is used to identify geometrical properties of the thrust plate and various locations of the plane are possible.
[0076] FIGS. 5a, 5b show (a) a bottom view of exemplary protrusions at a first side of a thrust plate according to one embodiment of the current invention and (b) an overlap of the protrusions at the first side and the recesses at the second side. In this embodiment, the protrusions and the recesses form an exemplary pattern. The thrust plate 140a according to the embodiment example depicted in FIG. 5a comprises a plurality of protrusions 270a. The plurality of protrusions 270a are illustrated in black and extend from the surface of the first side of the thrust plate 140a. As can be seen, the protrusions 270a are distributed in an annular fashion. Further, as can also be seen, the protrusions 270a do not necessarily have the same shape. Distributing the protrusions 270a in an evenly manner as is done in the embodiment example of FIG. 3a provides for a symmetric support of the orbiting scroll plate and improves the durability of the scroll compressor.
[0077] In FIG. 5b the overlap of the protrusions 270a with recesses 220a at the second side of the thrust plate 140a is illustrated. The recesses 220a are illustrated as dashed lines. As can be seen in FIG. 5b, each protrusion 270a is located in an area that overlaps with a location of a recess 220a. Further, the area covered by the recesses 220a is larger than the area covered by the protrusions. Such a configuration provides improved soft contact as will be described in more detail with respect to FIGS. 6a to 6c. The recesses 220a formed at the second side of the thrust plate 140a are connected in order to form a pattern on the surface of the second side of the thrust plate 140a.
[0078] FIGS. 5a, 5b also illustrate further features of the thrust plate. The thrust plate 140a comprises two holes 280, which can receive pins of an Oldham coupling, so that the pins of the Oldham coupling can reach through the body of the thrust plate 140a and engage the orbiting scroll plate. Further, the thrust plate 140a comprises an aperture 230 in the center of its body. The aperture 230 is configured to receive a portion of a crankshaft, so that the crankshaft can reach through the body of the thrust plate 140a and can engage an orbiting scroll plate.
[0079] FIGS. 6a, 6b, 6c show schematics of the overlap of a protrusion and a recess in a direction perpendicular to the plane defined by the disk-shaped body of the thrust plate, wherein (a) illustrates a protrusion 300a, which overlaps entirely with a recess 350a, while the recess 350a itself is larger, (b) illustrates a protrusion 300b and a recess 350b of the same size and (c) illustrates a recess 350c overlapping entirely with a protrusion 300c, while the protrusion 300c itself is larger.
[0080] In FIGS. 6a to 6c, the solid lines illustrate a protrusion, whereas the dashed lines illustrate a recess. Hatched areas indicate overlap between the protrusion and the recess in a direction perpendicular to the plane, wherein the plane is the image plane of FIGS. 6a to 6c. In FIG. 6a, the protrusion 300a overlaps entirely with the recess 350a, but a portion of the recess 350a does not overlap with any portion of the protrusion 300a. In other words, the recess 350a is greater than the protrusion 300a. The non-overlapping portion of the recess 350a may extend outwardly in any in-plane direction for about 1 to 2 mm. Said portion may also be referred to as a buffer or transition region. In FIG. 6b, the protrusion 300b overlaps entirely with the recess 350b and the recess 350b overlaps entirely with the protrusion 300b. In other words, the protrusion 300b and the recess 350b have the same size with respect to the plane and overlap with each other entirely. In FIG. 6c, the recess 350c overlaps entirely with the protrusion 300c, but a portion of the protrusion 300c does not overlap with any portion of the recess 350c. In other words, the protrusion 300c is greater than the recess 350c. In some cases, the configuration illustrated in FIG. 6c may be beneficial, even though there is hard contact in the small area in which the protrusion 300c does not overlap with any portion of the recess 350c. The hard contact leads to wear-off in these areas, which will re-distribute the contact stress. Preferably, the non-overlapping area has an extend of 2 mm or less.
[0081] FIGS. 7a, 7b show (a) a bottom view of an exemplary annular protrusion 270b at a first side of a thrust plate 140b according to a further embodiment of the current invention and (b) an overlap of the protrusion 270b at the first side and the recess 220b at the second side. In this embodiment, the protrusion and the recess form concentric rings. Similarly to FIGS. 5a, 5b, the protrusion 270b is illustrated in black and the recess is illustrated in dashed lines.
[0082] FIGS. 8a, 8b show (a) a bottom view of exemplary annular protrusions 270c1, 270c2 at a first side of a thrust plate 140c according to a further embodiment of the current invention and (b) an overlap of the protrusions 270c1, 270c2 at the first side and the recesses 220c1, 220c2 at the second side. In this embodiment, the protrusions 270c1, 270c2 and the recesses 220c1, 220c2 form concentric rings at the edges of the thrust plate. Similarly to FIGS. 5a, 5b, the protrusions 270c1, 270c2 are illustrated in black and the recesses 220c1, 220c2 are illustrated in dashed lines. Whereas the protrusion and recess in the embodiment example in FIGS. 7a, 7b are located in the center of the disk formed by the disk-shape body, the protrusions and recesses of the embodiment example of FIG. 8a, 8b are located at the outer edge and the inner edge, i.e. near the location of the aperture 230 in the center.
[0083] FIG. 9a, 9b show (a) a bottom view of exemplary protrusions 270d at a first side of a thrust plate 140d according to further embodiment of the current invention and (b) an overlap of the protrusions 270d at the first side and the recesses 220d at the second side. In this embodiment, the protrusions 270d and the recesses 220d extend radially from a center of the surface of the respective side of the thrust plate. In this embodiment example, the protrusions 270d are formed as radial bars, while the recesses 220d are formed as radial grooves. Similarly to FIGS. 5a, 5b, the protrusions 270d are illustrated in black and the recesses 220d are illustrated in dashed lines.
[0084] FIG. 10 shows a cross-sectional view of a thrust plate 140e according to a further embodiment of the current invention, wherein the recess 220e at the second side 200 is located beneath the surface 240 of the second side 200. This embodiment example achieves the soft contact without reducing the surface 240, which can contact the orbiting scroll plate. Therefore, such an embodiment example may provide a maximized contact surface between the thrust plate and the orbiting scroll plate and thereby a maximum of contact stress reduction.
[0085] FIGS. 11a-d show perspective views of (a) an orbiting scroll plate and (b), (c) thrust plates according to a further embodiment of the current invention as well as (d) an overlap of the protrusions and the recesses.
[0086] The embodiment example depicted in FIGS. 11a-d is an example of the system of an orbiting scroll plate and a thrust plate according to the current invention. The orbiting scroll plate 400 depicted in FIG. 11a comprises a base plate 450 having a frontside and a backside. At the frontside, the baseplate 450 comprises a spiral wrap 410 for being interleaved with a corresponding spiral wrap of a stationary scroll plate. At the backside, the base plate 450 comprises an aperture 420 for receiving a portion of a crankshaft configured to drive the orbiting motion of the orbiting scroll plate 400. Further, the backside of the base plate 450 comprises a plurality of recesses 430.
[0087] As is illustrated in FIG. 11b, the thrust plate 140f comprises a base plate with a first side and a second side. The first side comprises a plurality of protrusions 270f. When the system of the orbiting scroll plate 400 and the thrust plate 140f is assembled, the plurality of protrusions 270f and the plurality of recesses 430 of the orbiting scroll plate 400 overlap in a direction perpendicular to the base plate of the thrust plate 140f. As such, the system of the orbiting scroll plate 400 and the thrust plate 140f provides the benefit of avoiding hard contact, because the thrust plate is supported at the locations of the protrusions 270f, while there is contact between the orbiting scroll plate 400 and the thrust plate 140f at other locations because of the recesses 430.
[0088] Alternatively to the thrust plate 140f depicted in FIG. 11b, the thrust plate 140g depicted in FIG. 11c can also be used. Compared to the thrust plate 140f, the thrust plate 140g comprises a plurality of recesses 220g at locations overlapping with the plurality of protrusions 270g. In this case, recesses are provided to the backside of the orbiting scroll plate 400 as well as the second side of the thrust plate 140g, which may even further improve the hard contact avoidance.
[0089] In order to further illustrate the overlap of the protrusions and recesses, FIG. 11d depicts an overlay of the orbiting scroll plate 400 of FIG. 11a and the thrust plate 140f or 140g of FIGS. 11b, 11c. The overlay is illustrated similarly to the overlays depicted in FIGS. 5b, 7b, 8b, 9b. For illustrative purposes, the recesses illustrated in dashed lines may either be the recesses 430 of the orbiting scroll plate 400 or the recesses 270g of the thrust plate 140g. As is depicted in FIG. 11d, the recesses preferably cover a larger section than the protrusions in order to allow for sufficient overlap even if the orbiting scroll plate 400 is orbiting relatively to the thrust plate 140f or thrust plate 140g, respectively.
[0090] What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims.
