JP6246693B2 - Scroll member and scroll type fluid machine - Google Patents

Description

  The present invention relates to a scroll member and a scroll fluid machine.

  In a scroll fluid machine such as a scroll compressor, generally, improving the sealing performance between the tip surface of a blade (lap) and the surface (thrust surface) in contact with the end surface of the other scroll member leads to improved performance. Patent Document 1 discloses that a coating film is formed on at least one thrust surface of the fixed scroll member and the orbiting scroll member in order to improve the sealing performance.

JP 2008-151009 A

  When mass producing scroll members having a coating layer on the thrust surface, there is a problem that it is difficult to form a uniform coating layer. In particular, if the coating layer is formed on the side surface of the blade, there is a problem that a gap is formed between the blade of the other scroll member and the sealing performance is deteriorated.

  On the other hand, this invention provides the technique which improves the sealing performance between scroll members in a scroll type fluid machine.

  The present invention provides a flat plate having a thrust surface, a spiral blade formed on the thrust surface, a coating layer formed on the thrust surface, and the coating layer around the blade on the thrust surface. Provided is a scroll member having a void portion that is not formed.

  Among the spirals of the blades, the outer space around the first region may be narrower than the inner space around the second region.

  The coating layer may have a step shape in a normal direction of the thrust surface.

  Of the thrust surface, the coating layer may not be formed inside the spiral of the blade.

  The present invention also provides a first flat plate having a first thrust surface, a first scroll member having a spiral first blade formed on the first thrust surface, a second flat plate having a second thrust surface, and A second scroll member formed on the second thrust surface, having a spiral second blade forming a compression chamber with the first blade, and revolving relative to the first scroll member; Provided is a scroll fluid machine having a coating layer formed on a first thrust surface, and a gap portion where the coating layer is not formed around the first blade on the first thrust surface.

  The coating layer may have a step shape in a normal direction of the first thrust surface.

  The magnitude | size of the direction parallel to the said thrust surface of the convex part in the said level | step difference shape may be below the turning radius of the said scroll member.

  According to the present invention, in the scroll fluid machine, it is possible to improve the sealing performance between the scroll members as compared with the configuration in which the coating layer is also formed around the blades.

1 is a cross-sectional view illustrating the structure of a scroll fluid machine 1 according to an embodiment. The schematic diagram which shows the structure of the movable scroll member 4. FIG. The schematic diagram which shows the structure of the movable scroll member 4. FIG. Engagement between the movable scroll member according to the comparative example and the other-side blade. Engagement of the movable scroll member according to the present embodiment and the counterpart blade. FIG. 3 is a schematic diagram showing a cross-sectional structure of a coating layer 44. FIG. 4 is a schematic diagram showing a structure of a coating layer 44. FIG. 6 is a schematic diagram showing another example of the structure of the coating layer 44. The figure which shows another example of the cross-section of the coating layer. The other example of the shape of the coating layer 44 seen from the direction perpendicular | vertical to a thrust surface.

  FIG. 1 is a cross-sectional view illustrating the structure of a scroll fluid machine 1 according to an embodiment. In this example, the scroll fluid machine 1 is a compressor (scroll compressor) applied to an automotive air conditioner. The scroll fluid machine 1 includes a housing 2, a shaft 3, a movable scroll member 4, and a fixed scroll member 5.

  The housing 2 is fixed to an automobile engine (not shown). The interior of the housing 2 is partitioned into a compression chamber S1 in which the movable scroll member 4 and the fixed scroll member 5 are located, and a discharge chamber S2 formed on the right side in the drawing with respect to the fixed scroll member 5. The compression chamber S1 is provided with a suction hole (not shown) for sucking a gas (fluid) such as a refrigerant. The discharge chamber S2 is provided with a discharge hole (not shown) for discharging gas.

  The shaft 3 transmits the driving force of the engine to the movable scroll member 4. The shaft 3 can rotate in the housing 2. The shaft 3 has a small diameter part 31, a large diameter part 32, and a crankpin 33. The small diameter part 31 receives the driving force of the engine. The shaft center of the shaft 3 extends in the horizontal direction in the figure. The large diameter portion 32 is directly connected to the small diameter portion 31 in the axial direction. The crank pin 33 is directly connected to the large diameter portion 32 in the axial direction. The crank pin 33 is provided at a position eccentric with respect to the rotation axis of the shaft 3.

  The movable scroll member 4 and the fixed scroll member 5 form a compression chamber. The movable scroll member 4 and the fixed scroll member 5 relatively revolve (turn). Specifically, the fixed scroll member 5 is fixed to the housing 2, and the movable scroll member 4 revolves (turns) with respect to the fixed scroll member 5. Here, “revolution” means that one member moves in a circle around another member.

  The movable scroll member 4 has an end plate 41 and a blade (wrap) 42. The end plate 41 is a disk-shaped flat plate having a predetermined diameter (for example, 150 mm). The blades 42 are formed on the thrust surface of the end plate 41. The thrust surface of the movable scroll member 4 refers to the surface facing the fixed scroll member 5. The blades 42 extend in a direction perpendicular to the thrust surface. When viewed from a direction perpendicular to the thrust surface, the blades 42 have a spiral shape (specifically, for example, a shape along an involute curve).

  The fixed scroll member 5 has an end plate 51 and a blade 52. The end plate 51 is a disk-shaped flat plate having a predetermined diameter (for example, 150 mm). The blades 52 are formed on the thrust surface of the end plate 51. The thrust surface of the fixed scroll member 5 refers to the surface facing the movable scroll member 4. The blades 52 extend in a direction perpendicular to the thrust surface. When viewed from a direction perpendicular to the thrust surface, the blade 52 has a spiral shape.

  The blades 42 and 52 are engaged with each other to form the compression chamber S1. That is, the compression chamber S <b> 1 is a space surrounded by the blades 42, the blades 52, the end plate 41, and the end plate 51.

  The shaft 3 is rotated by the driving force of the engine. As the shaft 3 rotates, the crankpin 33 revolves (turns) around the rotation axis. The crank pin 33 transmits this rotational force to the movable scroll member 4. That is, the movable scroll member 4 revolves (turns) with respect to the fixed scroll member 5 as the shaft 3 rotates.

  The scroll fluid machine 1 further includes a bearing 6, an eccentric bush 7, and a bearing 8. The bearing 6 supports the large diameter portion 32. The eccentric bush 7 supports the crank pin 33. The eccentric bush 7 has an inner peripheral surface portion 7a and an outer peripheral surface portion 7b. When viewed from the axial direction, the circles of the inner peripheral surface portion 7a and the outer peripheral surface portion 7b are off the center, that is, both are eccentric. The inner peripheral surface portion 7 a slides with the crank pin 33. The outer peripheral surface portion 7 b slides with the movable scroll member 4.

  On the end plate 41 of the movable scroll member 4, a ring-shaped boss 43 is formed on the surface opposite to the blade 42. A bearing 8 is provided on the inner peripheral surface of the boss 43. The bearing 8 supports the eccentric bush 7. When the bearing 8 is integrated with the movable scroll member 4 and revolves around the small diameter portion 31, the outer peripheral surface portion 7 b of the eccentric bush 7 slides with the inner surface of the bearing 8. A mechanism is provided between the end plate 41 of the movable scroll member 4 and the housing 2 to prevent the movable scroll member 4 from rotating about a rotation axis passing through the crankpin 33. Here, “spinning” means that a certain member rotates around a rotation axis inside the member.

  A hole 53 is provided in the center of the end plate 51 of the fixed scroll member 5 for allowing the refrigerant to flow from the compression chamber S1 to the discharge chamber S2. The hole 53 is opened and closed by a thin plate-like reed valve 10.

  Refrigerant is sucked into the compression chamber S1 from an intake port (not shown). When the volume of the compression chamber S1 decreases as the movable scroll member 4 rotates, the refrigerant sucked into the compression chamber S1 is compressed. The compressed refrigerant passes through the hole 53 and the reed valve 10 and flows into the discharge chamber S2. The refrigerant flowing into the discharge chamber S2 is discharged from a discharge hole provided in the housing 2.

  FIG. 2 is a schematic diagram showing the structure of the movable scroll member 4. 2A is a view as seen from the direction perpendicular to the thrust surface (that is, the axial direction of the shaft 3), and FIG. 2B is a cross-sectional view taken along the line II-II in FIG. A coating layer 44 is formed on the thrust surface of the end plate 41. The coating layer 44 is a layer for improving the sealing performance of the thrust surface or for improving the sliding characteristics. The coating layer 44 includes, for example, a binder resin and a solid lubricant. Examples of the binder resin include polyamideimide resin, polyimide resin, PEEK (polyetheretherketone), diisocyanate-modified, BPDA-modified, or sulfone-modified resin, polyamide resin, epoxy resin, and phenol resin of these resins. 1 or more types are used. As the solid lubricant, for example, at least one of graphite, carbon, molybdenum disulfide, polytetrafluoroethylene, boron nitride, tungsten disulfide, fluorine-based resin, and soft metal (for example, Sn, Bi, etc.) is used. . The coating layer 44 may contain an additive such as a hard material in addition to or instead of the binder resin and the solid lubricant. Alternatively, the coating layer 44 may be formed of only a solid lubricant or a binder resin.

  The base material (portion excluding the coating layer 44) of the movable scroll member 4 is made of cast iron, for example. Alternatively, the base material of the movable scroll member 4 can be subjected to various processing processes such as casting, sintering, forging, cutting, pressing, welding, and surface treatment on various materials such as aluminum, stainless steel, and ceramic. It may be formed. The coating layer 44 is formed by applying, drying, and baking a precursor solution prepared by dispersing a solid lubricant in a binder resin on a base material shaped into a movable scroll shape. The precursor solution is applied by, for example, a spray method, a roll transfer method, a tumbling method, a dipping method, a brush coating method, a printing method (pad printing or screen printing), and the like.

  The blade | wing 42 has a spiral shape, as FIG. 2 shows. The space | interval of the blade | wing 42 and the blade | wing 42 in this spiral is 50 mm or less, or 20 mm or less, for example.

  In this example, the coating layer 44 is not formed around the blades 42 when viewed from the direction perpendicular to the thrust surface. That is, a portion where the coating layer 44 is not formed is formed around the blade 42 on the thrust surface of the end plate 41. This portion is referred to as “gap 45”. That is, the gap 45 is a portion of the thrust surface of the end plate 41 around the blade 42 where the coating layer 44 is not formed and the base material is exposed. The reason for providing the gap 45 is as follows.

  FIG. 3A is a diagram illustrating meshing of a movable scroll member and a counterpart blade according to a comparative example. The comparative example shows a movable scroll member manufactured by a design in which a coating layer is formed without providing a gap around the blade 42 on the thrust surface. Even if the gap is zero, a certain percentage of products in which the coating layer 44 is formed on the side surfaces of the blades 42 due to tolerance (variation) during mass production is manufactured. When the movable scroll member having the coating layer 44 formed on the side surface of the blade 42 is inclined with respect to the blade 52 of the stationary scroll member 5 on the other side, the coating layer 44 formed on the side surface of the blade 42 causes the blade 42 and A gap between the blades 52 becomes large. That is, the sealing performance between the movable scroll member 4 and the fixed scroll member 5 is deteriorated. In the drawing, the fixed scroll member 5 is depicted as being tilted, but the movable scroll member 4 is actually tilted.

  FIG. 3B is a diagram showing meshing of the movable scroll member and the counterpart blade according to the present embodiment. A gap 45 is provided around the blade 42 on the thrust surface. The width of the gap 45 is larger than the tolerance of the coating layer 44 at the time of manufacture. Note that the “width” of the gap 45 refers to the length of the gap 45 in the radial direction (radial direction) of the end plate 41. The width B of the gap 45 is, for example, 0.1 to 1 mm.

  Since the gap 45 is provided, the coating layer 44 is not formed on the side surface of the blade 42. Therefore, even if the blade 42 of the counterpart movable scroll member 4 is tilted and hit, the gap between the blade 52 and the blade 42 is narrower than the comparative example of FIG. 3A. That is, the sealing performance between the movable scroll member 4 and the fixed scroll member 5 is improved.

  FIG. 4 is a schematic diagram showing a cross-sectional structure of the coating layer 44. The coating layer 44 has a so-called step land shape. The step land shape means a shape having a height difference, that is, a step in a direction perpendicular to the thrust surface. The step land shape is formed for the purpose of easily discharging foreign matter that has entered the surface of the coating layer 44. That is, the foreign matter that has entered the surface of the coating layer 44 is discharged together with, for example, lubricating oil through a groove (concave portion) between two lands (convex portions) in the step land shape. Further, the lubricating oil can be held in the groove (concave portion), and the fluid lubrication region can be expanded to reduce the friction.

  In this example, the coating layer 44 has a two-layer structure of a first layer 441 and a second layer 442. The first layer 441 is uniformly formed on the thrust surface (excluding the portion corresponding to the gap 45). The second layer 442 protrudes upward in the thrust surface with respect to the first layer 441. The second layer 442 forms a land (island) shape.

  FIG. 5 is a schematic diagram showing the structure of the coating layer 44 as viewed from a direction perpendicular to the thrust surface. In this example, the land portion formed by the second layer 442 has a quadrangular shape. The plurality of land portions are arranged in a lattice shape, that is, a matrix shape.

  FIG. 6 is a schematic view showing another example of the structure of the coating layer 44 as seen from the direction perpendicular to the thrust surface. In this example, the land portion formed by the second layer 442 has a circular shape. The plurality of land portions are arranged in a staggered manner, that is, alternately.

  Here, from the viewpoint of improving the foreign matter discharge performance, the size of one land portion, that is, the maximum length in the direction horizontal to the thrust surface, is preferably equal to or less than the relative turning diameter of the two scroll members. For example, it is preferable that the length of the diagonal line of the quadrangle in the example of FIG. 5 or the diameter of the circle in the example of FIG. In addition, the level | step difference in a step land shape is 1-50 micrometers, for example, Preferably it is 1-20 micrometers. Moreover, the thickness of the coating layer 44 is 1-50 micrometers, for example, Preferably it is 1-20 micrometers. The step land shape is formed by, for example, pad printing or screen printing.

  Thus, by adopting a structure having a step in the coating layer 44, foreign matter can be easily discharged. One of the foreign matters that enter the surface of the coating layer 44 is the abrasion powder of the resin of the coating layer 44. When the wear powder is in a volume, there is a possibility that seizure occurs or the counterpart material comes into contact with each other. However, in the present embodiment, since the coating layer 44 has a step land shape, foreign matters can be easily discharged, and the possibility of these problems occurring can be reduced.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. Hereinafter, some modifications will be described. Two or more of the following modifications may be used in combination.

  FIG. 7 is a diagram showing another example of the cross-sectional structure of the coating layer 44. In the example of FIG. 7A, the coating layer 44 is not a two-layer structure but a single-layer structure. A portion where the base material is exposed is a step portion (groove portion), and a portion where the coating layer 44 is formed is a land portion. In the example of FIG. 7B, the coating layer 44 has a two-layer structure, but the first layer 441 is not uniformly formed on the thrust surface and has a two-dimensional pattern. That is, the step part has a two-stage shape.

  The width of the gap 45 may not be uniform in all portions of the blade 42. For example, the gap in the outer region of the spiral of the blade 42 may be narrower than the void in the inner region.

  FIG. 8 is a diagram illustrating another example of the shape of the coating layer 44 as viewed from the direction perpendicular to the thrust surface. In this example, the coating layer 44 is not formed inside the spiral of the blade 42, and the coating layer 44 is formed only outside the outermost periphery of the spiral of the blade 42 on the thrust surface. That is, all the insides of the spirals are gaps 45, which are wider than the outside gaps on the outermost periphery of the spirals. In general, it is difficult to form a uniform coating layer on a portion having a complicated shape such as the inside of the spiral of the blade 42. According to the example of FIG. 8, the manufacturing cost can be further reduced as compared with the case where the coating layer 44 is formed even inside the spiral of the blade 42.

  The shape of the land portion in the step land shape of the coating layer 44 viewed from the direction perpendicular to the thrust surface and the arrangement thereof are not limited to those illustrated in FIGS. 5 and 6. The land portion may be a polygon other than a rectangle, an ellipse, or the like. Further, the arrangement is not limited to a lattice shape and a staggered shape, and may be a random arrangement, for example.

  The cross-sectional shape perpendicular to the thrust surface of the land portion in the step land shape of the coating layer 44 is not limited to a quadrangle. An ideal quadrangular corner may have a rounded shape, or the surface may have an arc shape.

  The scroll fluid machine 1 in which the movable scroll member 5 according to the present embodiment is used is not limited to the one illustrated in FIG. The movable scroll member 5 according to the present embodiment may be applied to, for example, a so-called high pressure chamber type scroll compressor. The high-pressure chamber type scroll compressor refers to a compressor having a structure in which a housing includes a chamber that accommodates at least an orbiting scroll member. In a high-pressure chamber type scroll compressor, compared to a low-pressure chamber type scroll compressor, the load applied to the thrust surface is high, and a problem that a problem of one-sided contact or foreign matter is likely to occur. That is, the movable scroll member 5 according to the present embodiment is suitable for a high-pressure chamber type scroll compressor.

  Further, the movable scroll member 5 according to the present embodiment may be applied to a fluid machine other than the compressor, such as an air compressor or a pump.

  In the embodiment, the example in which the coating layer 44 and the gap 45 are formed on the thrust surface of the movable scroll member 4 has been described, but the coating layer and the gap may be formed on the thrust surface of the fixed scroll member 5. In short, the coating layer and the gap may be formed on at least one of the thrust surfaces of the movable scroll member 4 and the fixed scroll member 5.

DESCRIPTION OF SYMBOLS 1 ... Scroll type fluid machine 2 ... Housing 3 ... Shaft 31 ... Small diameter part 32 ... Large diameter part 33 ... Crank pin 4 ... Movable scroll member 41 ... End plate 42 ... Blade 44 ... Coating layer 441 ... 1st layer 442 ... 2nd layer 45 ... Gap 5 ... Fixed scroll member 51 ... End plate 52 ... Blade 53 ... Hole 6 ... Bearing 7 ... Eccentric bush 8 ... Bearing

Claims (7)

A flat plate having a thrust surface;
Spiral blades formed on the thrust surface;
Oite on the thrust surface, and a resin coating layer formed in a region including a region corresponding to the radial direction inner side of the vane,
A scroll member having a void portion in which the resin coating layer is not formed around the blade on the thrust surface. Of spiral of the blade, wherein the first gap portion around the first region, characterized in that narrower than second gap part of the second region surrounding existing inside in the radial direction to the next of the first cavity portion Item 2. The scroll member according to Item 1. The scroll member according to claim 1, wherein the resin coating layer has a step shape in a normal direction of the thrust surface. The scroll member according to any one of claims 1 to 3, wherein the resin coating layer is not formed inside the spiral of the blades in the thrust surface. A first scroll member having a first flat plate having a first thrust surface and a spiral first blade formed on the first thrust surface;
A second flat plate having a second thrust surface and a spiral second blade formed on the second thrust surface and forming a compression chamber with the first blade, and relative to the first scroll member; A second scroll member that pivots to
Oite the first thrust surface, and a resin coating layer formed in a region including a region corresponding to the radial direction inner side of the vane,
A scroll type fluid machine having a void portion in which the resin coating layer is not formed around the first blade on the first thrust surface. The scroll fluid machine according to claim 5, wherein the resin coating layer has a step shape in a direction normal to the first thrust surface. The maximum length in a direction parallel to the first thrust surface of the projection in the step shape A scroll fluid machine according to claim 6, characterized in that the pivot straight diameter or less under the scroll member.