JP2022056199A - Rotor for scroll compressor and scroll compressor - Google Patents

Abstract

To provide a rotor for a scroll compressor which can alleviate a stress concentration while reducing its weight, and is high in versatility, and the scroll compressor having the rotor.SOLUTION: A scroll rotor 1 comprises a substantially-flat plate-shaped baseboard 2 and a spiral scroll blade 3 substantially orthogonally extending from the baseboard 2, forms a compression chamber between a mating rotor and itself, compresses fluid, and is constituted while including a resin part. The scroll blade 3 has a circular arc part 4 having a cross section of a circular arc shape which is composed of a resin part at a root connected to the baseboard 2, and cut along a height direction of the scroll blade 3, and the circular arc part 4 is arranged at least at a part of the scroll blade 3. When setting a dimension of the scroll blade 3 in the height direction as V, and setting a dimension of the scroll blade 3 in a direction vertical to the height direction as H, a relationship of V>H is satisfied.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotor for a scroll compressor mounted on an air conditioner, a refrigerator, or the like, and a scroll compressor including the rotor.

In the scroll compressor, a fixed rotor having a substrate and a spiral scroll blade standing on the surface of the substrate and a movable rotor having a spiral blade standing on the surface of the substrate and the substrate are respectively arranged on the scroll blade. It is meshed to form a compression chamber between them. This compression chamber moves toward the center of the spiral by the action of the movable rotor that revolves around the axis of the fixed rotor, and the compressed fluid such as gas is compressed.

As described in Patent Document 1, most of the rotors for scroll compressors are conventionally produced by cutting a blank made by die casting or forging aluminum. However, since it is difficult to obtain the accuracy required for the rotor only by aluminum casting or forging aluminum, cutting is performed on almost all the parts in order to obtain the shape accuracy. Therefore, the manufacturing cost tends to be high. Further, since the rotor swings, it is desirable that the rotor is as light as possible, but there is a limit to the use of aluminum.

On the other hand, it has also been proposed to use resin for the rotor. For example, in Patent Document 2, polyphenylene sulfide resin, polyether ether ketone resin, all-aromatic polyester resin, nylon-4,6 resin, polyether sulfone resin, polyetherimide resin and the like are used as base resins, and whisker and heat resistance are used. A resin rotor is manufactured by injection molding a resin composition containing a sex fiber and a powdery solid lubricant. By using a predetermined resin composition, the weight is reduced and the dimensional accuracy, strength, and heat resistance are improved. In this way, by changing the rotor to a resin product, it becomes possible to select a manufacturing method such as injection molding that can obtain higher dimensional accuracy than casting or forging, and it is also possible to omit cutting.

Japanese Unexamined Patent Publication No. 1-155001 Japanese Unexamined Patent Publication No. 63-301258

However, since the rotor using resin is inferior in strength to the rotor made of aluminum, a large stress generated at the base of the scroll blade becomes a problem. In order to withstand this stress, for example, it is necessary to use a very expensive high-strength resin, or to set a limit on the maximum discharge pressure or the size of the rotor, and there is room for improvement in terms of versatility. ..

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a highly versatile scroll compressor rotor capable of alleviating stress concentration while reducing the weight, and a scroll compressor provided with the rotor. And.

The rotor for a scroll compressor of the present invention (hereinafter, also simply referred to as a scroll rotor) includes a substantially flat plate-shaped substrate and a spiral scroll blade extending substantially at a right angle from the substrate, and is between the rotor on the other side. A rotor for a scroll compressor that forms a compression chamber and compresses a fluid. The rotor for a scroll compressor includes a resin portion, and the scroll blade has a resin portion at a base connected to the substrate. The cross section cut along the height direction of the scroll wing has an arcuate arcuate portion, and the arcuate portion is provided in at least a part of the scroll wing and is in the height direction of the scroll wing. When the dimension (height dimension) is V and the dimension (width dimension) in the direction perpendicular to the height direction of the scroll blade is H, the relational expression V> H is satisfied. The "arc shape" in the present invention includes not only a perfect circle or an elliptical arc shape but also various curved shapes.

It is characterized in that the dimension V and the dimension H of the arc portion satisfy the relational expression of 1.5 ≦ V / H ≦ 2.5. Further, the dimension V and the dimension H of the arc portion satisfy the relational expression of 2.0 ≦ V / H ≦ 2.3.

The resin portion is characterized by using an aromatic polyamide resin, a polyphenylene sulfide (PPS) resin, a polyetheretherketone (PEEK) resin, a polyetherimide (PEI) resin, or a liquid crystal polymer (LCP) as a base resin. ..

The resin portion is characterized by containing reinforcing fibers of glass fiber, carbon fiber, or aramid fiber. Further, the average fiber length of the reinforcing fibers is 0.5 mm or more.

The rotor for a scroll compressor is composed of the resin portion and the core metal, and is characterized in that the core metal is embedded in at least a part of the scroll blade along the spiral shape of the scroll blade. In the present invention, the term “embedded” is not limited to the case where all of the core metal is completely embedded in the resin portion, but also includes the case where a part of the core metal is exposed from the resin portion and embedded.

The scroll blade is characterized in that the core metal is embedded around the winding center of the scroll blade from the central end portion of the scroll blade to a portion of 270 ° or less in the winding direction. do. Further, in the scroll blade, the core metal is embedded around the winding center of the scroll blade from the central end portion of the scroll blade to a portion of 120 ° or less in the winding direction. It is a feature.

The core metal has a wall portion embedded in the scroll blade and a circular flange portion integrally formed with the wall portion, and the flange portion is embedded in the substrate.

The flange portion has a diameter of 90% or more of the hole diameter of the bearing hole provided on the back surface side of the substrate.

The scroll blade is characterized in that the thickness of the resin portion covering the core metal is 0.8 mm to 1.5 mm. Further, the scroll blade is characterized in that the thickness of the resin portion covering the core metal is 1.0 mm to 1.3 mm.

The core metal and the resin portion are bonded to each other.

The maximum value of the adhesive gap between the core metal and the resin portion is 0.1 mm or less, excluding the adhesive pool portion. The maximum value of the adhesive gap between the core metal and the resin portion is 0.05 mm or less, excluding the adhesive pool portion.

The core metal is characterized by being made of a sintered metal material.

The scroll compressor of the present invention includes a fixed rotor having a spiral fixed-side scroll blade erected on the substrate and its surface, and a movable rotor having a spiral movable-side scroll blade erected on the substrate and its surface. A scroll compressor in which a compression chamber is formed between the fixed side scroll blade and the movable side scroll blade, and the movable rotor is revolved around the axis of the fixed rotor to compress gas, and at least the movable side. The rotor is a rotor for a scroll compressor of the present invention.

Since the rotor for a scroll pump of the present invention is configured to include a resin portion, the weight can be reduced as compared with the rotor made of aluminum. Further, at the base of the scroll blade where a large stress is generated, an arc portion having an arcuate cross section satisfying the relational expression of height dimension V> width dimension H is provided. In this case, an asymmetric arc portion shifted in the height direction is formed as compared with the arc portion having a single radius of curvature. Therefore, it is necessary to secure a large chamfer while considering the dimensional limitation of the scroll rotor. Can be done. As a result, the stress concentration generated at the base of the scroll blade can be relaxed.

As a result, the following effects can be obtained, resulting in a highly versatile scroll rotor. The strength requirements for resin materials will be relaxed, and the choices of resin materials will increase. For example, it will be possible to select resins with excellent items other than chemical resistance, cost, and strength. Further, the restrictions on the size of the rotor and the discharge pressure are relaxed, and the resin rotor can be applied to a large machine having a higher scroll blade and a high pressure machine having a higher discharge pressure. Furthermore, the relaxation of stress concentration leads to an improvement in rotor life and reliability.

Since the dimension V and the dimension H of the arc portion satisfy the relational expression of 1.5 ≦ V / H ≦ 2.5, the stress concentration can be suitably relaxed.

The rotor for a scroll compressor is composed of a resin part and a core metal, and the core metal is embedded along the spiral shape of the scroll blade at least in a part of the scroll blade, so that the scroll blade that causes a large stress is the core metal. Since it can be effectively reinforced by the above, the stress generated in the resin portion can be reduced.

In the scroll blade, the core metal is embedded around the winding center of the scroll blade from the central end of the scroll blade to a portion of 270 ° or less in the winding direction, so that a large stress is applied to the scroll blade. It is possible to effectively reinforce only the part where the problem occurs, and it is possible to further improve the strength and reduce the weight.

The core metal has a wall portion embedded in the scroll blade and a circular flange portion integrally formed with the wall portion. Since the flange portion is embedded in the substrate, the substrate is reinforced by the flange portion. Deformation of the substrate can be suppressed, and as a result, the stress concentration generated at the base of the scroll flange can be further relaxed.

In the scroll compressor of the present invention, at least the movable rotor is the rotor for the scroll pump of the present invention, which leads to reduction of the movable mass, and as a result, noise reduction and vibration reduction effects can be expected. Moreover, since the weight of the counterweight can be reduced, further weight reduction can be expected as a whole.

It is a top view which shows an example of the scroll rotor of 1st Embodiment. FIG. 3 is a cross-sectional view taken along the line AA of the rotor of FIG. It is the B part enlarged view of FIG. It is a graph which shows the relationship between the radius of curvature and the maximum value of a principal stress. It is a graph which shows the relationship between V / H and the maximum value of a principal stress. It is a top view which shows another example of the scroll rotor of 1st Embodiment. It is a top view which shows another example of the scroll rotor of 1st Embodiment. It is a schematic cross-sectional view which shows an example of the scroll compressor of this invention. It is a perspective view which shows an example of the scroll rotor of 2nd Embodiment. It is a top view of the scroll rotor of the 2nd Embodiment. It is a schematic cross-sectional view of the scroll rotor of 2nd Embodiment. It is a graph which shows the relationship between the thickness of a resin part, and the maximum value of a principal stress. It is a graph which shows the relationship between the thickness of a flange part and the maximum value of a principal stress. It is a perspective view which shows the other example of the scroll rotor of 2nd Embodiment. It is a figure which shows the stress distribution of a scroll rotor.

Hereinafter, the first embodiment of the rotor for a scroll compressor of the present invention will be described with reference to FIGS. 1 to 3. 1 is a plan view of the scroll rotor as viewed from the scroll blade side, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is an enlarged view of a portion B of FIG. This scroll rotor may be used as a fixed rotor or a movable rotor in the scroll compressor shown in FIG. 8 described later.

The scroll rotor 1 of FIG. 1 is an injection molded body of a resin composition, and a substrate 2 and a scroll blade 3 are integrally formed. The scroll rotor 1 includes a substantially flat plate-shaped substrate 2 and a spiral-shaped scroll blade 3 extending at a substantially right angle from the substrate 2. The planar shape of the substrate 2 is a circular shape, and for example, a gate mark (not shown) at the time of injection molding is formed in a substantially central portion of the substrate 2. The scroll blade 3 is formed so that the radius of curvature gradually increases from the inner end portion 3a, which is the central end portion, toward the outer end portion 3b. In the scroll blade 3, the side wall surface on the inner peripheral side of the spiral is the inner wall surface 3c, and the side wall surface on the outer peripheral side of the spiral is the outer wall surface 3d.

FIG. 2 shows a cross-sectional view cut along the height direction of the scroll blade. As shown in FIG. 2, the scroll blade 3 is integrally upright from the substrate 2. The tip end surface 3e of the scroll blade 3 is a sliding surface with the substrate of the facing rotor on the opposite side, and is a sealing surface for sealing the compressed fluid in the compression chamber. The tip end surface 3e may be formed with a mounting groove into which a spiral seal member (chip seal) can be mounted. The sealing member is in sliding contact with the substrate of the opposing rotor, so that the airtightness of the compression chamber is ensured. In this case, the mounting groove is formed as a concave groove closed in the end surface 3e on the distal end side without opening in the inner wall surface 3c and the outer wall surface 3d.

In the scroll blade 3, the tip arc portion 5 is provided at each of the connection points between the tip end surface 3e and the inner wall surface 3c and the tip end side end face 3e and the outer wall surface 3d. The tip arc portion 5 is formed so as to be substantially parallel to the arc portion provided at the base of the scroll blade of the mating rotor. Further, an arc portion 4 is formed at the base of the scroll blade 3. In this embodiment, an arc portion 4 is formed around the entire root of the scroll blade 3 connected to the inner side surface 2a of the substrate 2. That is, in this form, the arc portion 4 is provided at the inner end portion, the outer end portion, the inner wall surface 3c, and the root of the outer wall surface 3d of the scroll blade 3.

Here, a pressure load according to the discharge pressure is applied to the scroll blade 3 of the rotor 1. Further, since the scroll blade 3 is a wall-shaped portion attached to the surface of the substrate 2, the load condition is a so-called "cantilever that receives an evenly distributed load", and stress based on a large moment is applied to the root portion thereof. Occurs. In particular, when the base of the scroll blade is a corner with a sharp edge (pin angle) without a rounded edge, stress concentration causes a larger load to be generated at this portion.

As a method of relaxing the stress concentration as described above, first, it is conceivable to form an arc portion R (see FIG. 3) having a single radius of curvature r at the base of the scroll blade. Here, in the scroll rotor, the relationship between the radius of curvature r of the arc portion and the stress generated in the arc portion is shown in FIG. FIG. 4 shows the change in the stress value when the radius of curvature r is increased, where 1 is the stress value when the radius of curvature r is 0.05. As shown in FIG. 4, until the radius of curvature r is about 0.5, the stress decreases rapidly as the radius of curvature r increases, and then the stress gradually decreases. From this tendency, when an arc portion having a single radius of curvature r is provided at the base of the scroll blade, it is considered that the radius of curvature r is preferably 0.5 or more, and more preferably 0.8 or more.

On the other hand, in the scroll rotor, it is necessary to keep the gap between the scroll blade and the mating scroll blade small in order to secure the pump efficiency. Therefore, as shown in FIG. 2, when the arc portion 4 is provided at the base of the scroll blade 3, the tip arc portion C corresponding to the arc portion 4 at the base is also provided on the tip side of the mating scroll blade (dotted line in FIG. 2). Need to be provided. In such a case, for example, if the thickness of the scroll blade 3 is 3 mm to 4 mm and a tip seal having a width of about 2 mm is provided on the tip end surface 3e of the scroll blade 3, the radius of curvature r taken in the tip arc portion 5 of the scroll blade 3 is It will be about 0.5 mm to 1 mm. That is, the radius of curvature r is limited to some extent. On the other hand, there is no particular dimensional limitation in the height direction of the scroll blade 3.

Therefore, in the scroll rotor of the first embodiment, the arc portion is made large on the height direction side of the scroll blade without limitation. Specifically, as shown in FIG. 3, the dimension V in the height direction of the scroll wing 3 of the arc portion 4 provided at the base of the scroll wing 3 is in the direction perpendicular to the height direction of the scroll wing 3 ( It is made larger than the dimension H (in the width direction) (V> H). That is, in the scroll rotor 1, there is a large margin for taking a large radius of curvature in the height direction of the scroll blade 3, but in view of the fact that there is little dimensional margin in the width direction, the asymmetric arc portion 4 whose curvature is not constant. Is provided.

As shown in FIG. 3, the arc portion 4 is formed in an elliptical arc shape. In this case, the curvature of the arc portion 4 increases in the direction away from the substrate 2. The arc portion 4 is provided at the root on the inner peripheral side of the spiral of the scroll blade 3 and the root on the outer peripheral side of the spiral, respectively. The end portion of the arc portion 4 is smoothly connected to the inner side surface 2a of the substrate 2 and the inner wall surface 3c (or outer wall surface 3d) of the scroll blade 3. The shape of the arc portion 4 may satisfy the relationship of V> H, and is not limited to the elliptical arc. For example, the substrate side may be an arc having a predetermined radius, and the side wall surface side of the scroll blade may be an arc having a larger radius, and the arc portion may be formed by a composite arc in which these are continuously connected.

Subsequently, the stress generated in the arc portion 4 will be described with reference to FIG. FIG. 5 is a graph showing the change in stress when the dimension V shown in FIG. 3 is fixed to 0.8 mm and the dimension H is reduced. In the graph of FIG. 5, the horizontal axis is the ratio of the dimension V to the dimension H (V / H), and the vertical axis is the stress value generated when V / H = 1 (in this case, the radius of curvature r = 0.8). It is the ratio of the stress values generated when V / H is changed. As shown in FIG. 5, the stress is rapidly reduced until the V / H is about 1.5, the stress starts to increase when the V / H exceeds 2.5, and the V / H is about 5. It can be seen that the stress is about the same as V / H = 1.

Considering the result of FIG. 5 and the shape limitation of the scroll rotor that a large chamfer cannot be provided in the width direction, the relationship between the dimension V and the dimension H is preferably 1.5 ≦ V / H ≦ 2.5. By satisfying this relationship, the stress concentration generated at the base of the scroll blade can be further relaxed. Further, considering the processing error, 2.0 ≦ V / H ≦ 2.3 is more preferable.

For each dimension, specifically speaking, the V dimension is 0.5 mm to 1.2 mm and the H dimension is 0.75 mm to 3 mm after satisfying 1.5 ≦ V / H ≦ 2.5. Is preferable. Further, the arc portion described above is suitable for such a configuration because stress concentration can be relaxed while ensuring the width of the end face on the tip side even when the thickness of the scroll blade is relatively thin. The thickness T of the scroll blade (see FIG. 3) is, for example, 2 mm to 4 mm. The thickness T of the scroll blade is the distance between the inner wall surface 3c and the outer wall surface 3d.

Further, the V / H may be constant over the entire area of the arc portion 4 formed at the base of the scroll blade 3, or may change depending on the portion. In the latter case, the V / H of the arc portion 4 near the center of the spiral is set to the V / H of the arc portion 4 near the outside of the spiral, in view of the fact that the pressure near the center of the spiral is higher than that near the outside of the spiral. It is preferably larger than H. The V / H may change continuously along the winding direction of the spiral, or may change stepwise. When V / H changes, it is more preferable to change within the range of 1.5 ≦ V / H ≦ 2.5.

In the examples shown in FIGS. 1 to 3, the arc portion 4 is provided around the entire base of the scroll blade 3, but in the present invention, the arc portion 4 is provided on at least a part of the scroll blade 3. good. For example, as in the scroll rotor 6 of FIG. 6, the arc portion 4 (V> H) may be provided only at the root of the scroll blade 3 on the inner peripheral side. In this case, for example, an arc portion (V = H) having a single radius of curvature r is provided at the base of the scroll blade 3 on the outer peripheral side. In FIG. 6, an arc portion 4 (V> H) may be provided at the roots of the inner end portion 3a and the outer end portion 3b of the scroll blade 3.

Further, in addition to the root on the inner peripheral side of the spiral of the scroll blade 3 in FIG. 6, an arc portion (V> H) is provided at the root on the outer peripheral side, and then the arc portion on the inner peripheral side and the outer peripheral side are provided. The design of the R of the arc portion may be different. In general, since the resin has a higher compressive strength than the tensile strength, it is preferable to make the V / H of the arc portion on the inner peripheral side larger than the V / H of the arc portion on the outer peripheral side.

Note that, unlike the configuration of FIG. 6, the arc portion 4 (V> H) may be provided only at the root on the outer peripheral side of the spiral of the scroll blade 3. In this case, for example, an arc portion (V = H) having a single radius of curvature r is provided at the base of the scroll blade 3 on the inner peripheral side.

Further, as in the scroll rotor 7 of FIG. 7, the arc portion 4 (V> H) may be provided only at the root near the center of the spiral of the scroll blade 3. In FIG. 7, the arc portion 4 is provided at the root of the inner end portion 3a of the scroll blade 3, the root of a part of the inner wall surface 3c, and the root of a part of the outer wall surface 3d. Since the compression pressure is relatively low near the outside of the spiral, the arc portion 4 is not always necessary. Specifically, it is preferable to provide an arc portion 4 at the root of a portion 270 ° or less in the winding direction from the center side end portion 3a of the scroll blade 3 centering on the winding center O of the scroll blade, preferably 120 °. It is more preferable to provide the arc portion 4 at the base of the following portions. Further, it is more preferable that the dimension V and the dimension H of the arc portion 4 satisfy the relational expression of 1.5 ≦ V / H ≦ 2.5. In this way, stress concentration can be suitably relaxed.

Further, the arc portion may be designed in combination with the configuration of the core metal in the second embodiment described later. That is, the dimensions of the range in which the core metal is embedded in the winding direction from the central end of the scroll blade (see FIG. 10) and the arc portion 4 provided in the winding direction from the central end 3a of the scroll blade 3 It is preferable that V and the range in which the dimension H satisfies the relational expression of 1.5 ≦ V / H ≦ 2.5 are common. By doing so, it is possible to further suppress the generation of stress and relax the stress concentration.

Next, an example of a scroll compressor using the scroll rotor of the first embodiment shown in FIG. 1 as a fixed rotor and a movable rotor will be described with reference to FIG. FIG. 8 is a partial cross-sectional view of the compression mechanism portion of the scroll compressor. As shown in FIG. 8, the scroll compressor 19 includes a fixed rotor 8 having a substrate 9 and a fixed-side scroll blade 10 upright on the surface thereof, and a movable rotor 13 having a substrate 14 and a movable-side scroll blade 15 upright on the surface thereof. And have. The fixed rotor 8 and the movable rotor 13 are meshed with each other in an eccentric state, and a compression chamber 18 is formed between them. As the movable rotor 13 revolves around the axis of the fixed rotor 8, the compression chamber 18 moves toward the center of the spiral shape and the compressed fluid is compressed. The compressed compressed fluid is discharged from the discharge pipe through a discharge port (not shown) at the center of the fixed rotor 8.

In this compression step, each of the rotors 8 and 13 is pressured by the compressed compressive fluid. Then, stress is intensively generated at the base of the fixed side scroll blade 10 of the fixed rotor 8 and the base of the movable side scroll blade 15 of the movable rotor 13. However, as described above, the stress is diffused by providing the arcuate portions 11 and 16 satisfying a predetermined dimensional relationship at the root. Further, since the tip arc portions 12 and 17 having a shape complementary to the arc portions 11 and 16 of the mating rotor are provided on the tip side of each scroll blade 10 and 15, the gap between the scroll blades should be reduced. Can be done. As a result, the amount of fluid leaking from the compression chamber 18 is suppressed, and the compression efficiency of the refrigerant and the like can be maintained high.

The rotor for a scroll compressor of the first embodiment is made of a resin composition containing a base resin as a main component. As described above, the type of the base resin is not particularly limited because the strength requirement of the resin material is reduced by providing the arc portion having a predetermined shape. Therefore, the choices of the base resin are increased, and for example, a resin having an excellent cost can be used. From the viewpoint of slidability and strength, the base resin is preferably an aromatic polyamide resin, a PPS resin, a PEEK resin, a PEI resin, or an LCP.

It is preferable that the resin composition contains reinforcing fibers such as glass fiber, carbon fiber and aramid fiber. The reinforcing fiber is more preferably contained in an amount of 10 to 70% by mass, more preferably 15 to 50% by mass, based on the entire resin composition. If the blending amount of the reinforcing fiber is less than 10% by mass, the reinforcing effect is small, and if it exceeds 70% by mass, fluidity suitable for injection molding may not be obtained.

It is more preferable to use glass fiber or carbon fiber as the reinforcing fiber. The glass fiber is obtained by spinning from inorganic glass containing SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , CaO, MgO, Na ₂ O, K ₂ O, Fe ₂ O ₃ and the like as main components. Generally, non-alkali glass (E glass), alkali-containing glass (C glass, A glass) and the like can be used. Further, the carbon fiber can be used regardless of the type of raw material such as polyacrylonitrile-based (PAN-based), pitch-based, rayon-based, and lignin-poval-based mixture.

The average fiber length of the reinforcing fibers contained in the resin composition is not particularly limited, but is preferably 0.5 mm or more. In the present invention, the average fiber length is a number average fiber length. If the average fiber length is less than 0.5 mm, the reinforcing effect becomes small and the wear resistance may decrease. The upper limit of the average fiber length is, for example, 5 mm. The average fiber diameter of the glass fiber or carbon fiber is not particularly limited, but is, for example, 5 μm to 20 μm, preferably 10 μm to 20 μm. The average fiber diameter can be measured by an electron microscope or an atomic force microscope usually used in this field. The average fiber diameter can be calculated as a number average fiber diameter based on the above measurement.

Additives other than the reinforcing fibers may be added to the resin composition, if necessary, as long as the strength and injection moldability are not impaired. As other additives, for example, solid lubricants, inorganic fillers, antioxidants, antistatic agents, mold release materials and the like can be blended.

If necessary, each material constituting the above resin composition is mixed by a Henschel mixer, a ball mixer, a ribbon blender, or the like, and then melt-kneaded by a melt-kneading machine such as a twin-screw kneading extruder to pellet for molding. Can be obtained. As for the filling material, a side feed may be adopted when melt-kneading with a twin-screw extruder or the like. A rotor for a scroll pump can be obtained by injection molding using these molding pellets.

Next, a second embodiment of the scroll rotor of the present invention will be described. FIG. 9 shows an example of the scroll rotor of the second embodiment. FIG. 9 is a perspective view of the scroll rotor as viewed from diagonally above the scroll blade. The scroll rotor 21 of FIG. 9 includes a substantially flat plate-shaped substrate 22 and a spiral-shaped scroll blade 23 extending at a substantially right angle from the substrate 22. The basic configuration of the scroll rotor of the second embodiment is the same as that of the scroll rotor of the first embodiment, but in the first embodiment, the scroll rotor is made of a resin molded body, and the arc portion at the base of the scroll blade is formed. Whereas there was a feature, the second embodiment is characterized in that the scroll rotor is composed of a resin molded body and a core metal.

As shown in FIG. 9, the scroll rotor 21 is composed of a portion (resin portion) of a resin molded body and a core metal 24, and the scroll rotor 21 is characterized in that the core metal 24 is embedded in the scroll rotor 21. In the scroll rotor 21, the portion other than the core metal 24 is the resin portion. The core metal 24 has a disk-shaped flange portion 24a and a wall portion 24b that is integrally upright from the flange portion 24a. The flange portion 24a is embedded in the substrate 22, and the wall portion 24b is embedded in a part of the scroll blade 23. The wall portion 24b has a crescent shape in a plan view, and is embedded along the shape of the winding start portion of the spiral scroll blade 23. In the second embodiment, the metal core metal is embedded in at least a part of the scroll blade along the shape of the portion, so that the stress at the base of the scroll blade in which a large stress is generated is relaxed. In this form, the core metal is provided as a reinforcing member.

In the scroll rotor 21, the resin portion and the core metal 24 are adhered to each other, and an adhesive layer is interposed between them. The scroll rotor 21 can be obtained, for example, by preparing a resin molded body and a core metal in advance and adhering them using a well-known adhesive or adhesive tape. As the adhesive, for example, an epoxy-based adhesive, a phenol-based adhesive, a vinyl ether-based adhesive, a vinyl acetal-based adhesive, or the like can be used.

The bonding gap, which is the distance between the resin molded body and the core metal, is preferably such that the core metal can be lightly press-fitted. If it is press-fitted strongly, it may be deformed due to press-fitting or residual stress may remain. On the other hand, if the bonding gap is too large, the resin portion is easily deformed by the amount of the gap, and the force received by the resin portion cannot be transmitted to the core metal, so that the reinforcing effect of the core metal may be reduced. Therefore, the bonding gap is preferably 0.1 mm or less, more preferably 0.05 mm or less even at the largest portion. It should be noted that this adhesive gap does not include a concave adhesive reservoir for accumulating the adhesive.

The method of embedding the core metal 24 in the resin portion is not limited to the above-mentioned bonding method, and insert molding in which the molten resin is injected and filled in the mold to which the core metal is fixed can also be adopted. In the case of insert molding, the resin portion shrinks due to molding shrinkage, whereas the core metal does not shrink. Therefore, the residual stress due to the difference in shrinkage may cause a decrease in strength or deformation may occur, which may affect the dimensional accuracy of the component. Therefore, a method of adhering the resin molded body and the core metal is preferable.

Here, in the scroll rotor 1, a large stress is generated at the base of the scroll blade as described above, but the largest stress is generated at the base of the scroll blade near the center of the spiral. Therefore, in the second embodiment, it is preferable to provide a core metal at least near the center of the spiral of the scroll blade which is the maximum stress portion. From the viewpoint of the reinforcing effect, it is preferable to provide the core metal over the entire scroll blade, but the weight is increased by that amount, and the effect of weight reduction, which is one of the merits of resinification, is diminished. Therefore, in order to achieve both strength improvement and weight reduction by the core metal, it is preferable to provide the core metal in the scroll blade only near the center of the spiral of the scroll blade. The vicinity of the center of the spiral of the scroll blade means a portion where the angle θ shown in FIG. 10 described later is within 270 °.

FIG. 10 is a plan view of the scroll rotor of the second embodiment. Since the core metal cannot be seen in the plan view of FIG. 10, it is shown by a dotted line for convenience. The angle θ is an angle that advances in the winding direction from the inner end portion 23a with the winding center O of the scroll blade 23 as the center. It is more preferable that the core metal 14 is provided up to the portion where the angle θ is 180 °, and it is further preferable that the core metal 24 is provided up to the portion where the angle θ is 120 ° in order to further reduce the weight.

In the scroll rotor, it is considered that a large stress is generated particularly at the root of the scroll blade, and the other parts such as the tip portion (anti-root portion) of the scroll blade and the substrate to which the scroll blade is attached do not generate such a large stress. However, in the examples of FIGS. 9 and 10, the area of the flange portion 24a is increased to reinforce the central portion of the substrate 22. The diameter of the flange portion 24a is preferably 60% or more, more preferably 90% or more, and further preferably the same size as the hole diameter of the bearing hole 22b (see FIG. 11) provided on the back surface side of the substrate 22. The diameter of the flange portion 24a is set smaller than the diameter of the substrate 22, and is preferably 40% to 80% of the diameter of the substrate 22.

FIG. 11 is a schematic cross-sectional view of the scroll rotor of the second embodiment along the height direction. In FIG. 11, the flange portion 24a is embedded in the bearing hole 22b on the back surface side of the substrate 22, and the wall portion 24b is embedded in the scroll blade 23. In FIG. 11, the diameter of the flange portion 24a of the core metal 24 has the same size as the hole diameter of the bearing hole 22b, and is constrained in the axial direction. The flange portion 24a is exposed toward the back surface side of the substrate 12. On the other hand, the wall portion 24b is entirely covered with the resin portion and is not exposed on the surface of the scroll blade 23.

Here, the relationship between the thickness t of the resin portion covering the wall portion 24b and the stress will be described with reference to FIG. FIG. 12 is a calculation of the maximum value of the principal stress generated in the resin portion when the thickness t of the resin portion is changed. The thickness t of the resin portion is a length in a direction parallel to the thickness T of the scroll blade. As shown in FIG. 12, the thinner the thickness of the resin portion, the smaller the stress generated in the resin portion. That is, the thicker the core metal embedded in the scroll blade, the greater the reinforcing effect. However, if the portion of the core metal is made too thick, the thickness t of the resin portion becomes thin, which may cause problems such as poor fluidity during molding and welding of the scroll blades that require strength. Therefore, the thickness t of the resin portion around the core metal is preferably 0.5 mm or more. The preferred range of the thickness t is 0.8 mm to 1.5 mm, and the more preferable range is 1.0 mm to 1.3 mm. The thickness t does not have to be constant and may vary within each of the above ranges.

Further, FIG. 13 shows the relationship between the thickness of the flange portion of the core metal and the stress. FIG. 13 is a calculation of the maximum value of the principal stress generated in the resin portion when the thickness s (see FIG. 11) of the flange portion 24a is changed. As shown in FIG. 13, the thicker the flange portion, that is, the thinner the resin portion of the substrate 22, the smaller the stress generated in the resin portion of the scroll blade. However, if the thickness of the resin portion becomes too thin, the fluidity during molding may deteriorate. Therefore, the thickness of the resin portion is preferably 0.5 mm or more. The thickness s of the flange portion is set to, for example, 1.0 mm to 3.0 mm.

Subsequently, another example of the scroll rotor of the second embodiment is shown in FIG. The scroll rotor 31 of FIG. 14 has a different shape of the flange portion 34a of the core metal 34 as compared with the scroll rotor 21 of FIG. Specifically, the planar shape of the flange portion 34a is not a circular shape, but a crescent shape along the planar shape of the wall portion 34b. That is, the core metal 34 in FIG. 14 is configured to mainly reinforce only the scroll blade 33. Even in this configuration, the stress concentration generated at the base of the scroll blade 33 can be sufficiently relaxed as compared with the case where the round bar is used as the core metal or the case where the core metal is not used (only the resin portion).

The configuration of the flange portion may be either the configuration of FIG. 9 or the configuration of FIG. 14, but since the flange portion is smaller, the configuration of FIG. 14 is preferable from the viewpoint of weight reduction. On the other hand, since the reinforcing area of the substrate increases, the configuration shown in FIG. 9 is preferable from the viewpoint of stress relaxation. Actually, when the stress generated at the base of the scroll blade was compared between the configuration of FIG. 9 and the configuration of FIG. 14, the stress of the configuration of FIG. 9 was reduced to about 2/3 as compared with the configuration of FIG. It is presumed that this is because, as shown in the stress distribution diagram of FIG. 15, further force is applied to the base of the scroll blade due to the deflection deformation of the entire substrate which is the bottom surface. As shown in FIG. 15, a large stress (strain) is not generated at a specific part of the substrate, but it is considered that the strain generated little by little over the entire substrate affects the root of the scroll blade. Therefore, as shown in FIG. 9, it is considered that the deformation of the substrate can be suppressed by enlarging the flange portion of the core metal, and as a result, the stress relaxation at the base of the scroll blade can be further contributed.

As the material of the core metal, a sintered metal material or a molten metal material can be adopted. As the sintered metal material, iron-based, copper-iron-based, copper-based, stainless-steel, or the like can be used. Among these, it is preferable to use an iron-based sintered material because it has excellent compressive strength, bonding strength with a resin portion, and low cost. Examples of the molten metal material include iron, aluminum, an aluminum alloy, copper, and a copper alloy.

In the scroll rotor of the second embodiment, it is preferable to use a sintered metal material for the core metal. Compared to casting and forging, sintering makes it easier to make a large flange portion, has excellent dimensional accuracy, and makes it easier to control the above-mentioned bonding gap. In addition, no cutting process is required, and the manufacturing cost can be reduced. Since the sintered metal material has pores on its surface, the adhesive enters the pores when adhering, and it is easy to obtain high adhesive strength due to the anchor effect. Further, the sintered metal material has a smaller specific gravity than the molten metal material manufactured by casting or forging, and the effect of weight reduction can be easily obtained.

Further, the resin composition described in the first embodiment can be used for the resin portion of the scroll rotor of the second embodiment. The molding method of the resin portion is not particularly limited, and can be obtained by, for example, injection molding.

The scroll rotor of the present invention is not limited to the first embodiment and the second embodiment described above. For example, a scroll rotor in which a predetermined arc portion of the first embodiment and a core metal of the second embodiment are combined may be used. This scroll rotor is composed of a resin portion which is a molded body of a resin composition and a core metal, and a core metal conforming to the shape of a part of the scroll blade is embedded in at least a part of the scroll blade. Further, an arc portion satisfying the relational expression V> H is provided at the base of the scroll blade composed of the resin portion. In this way, by combining the characteristic configurations of each form, the stress generated at the base of the scroll blade can be further relaxed. As the arc portion and the core metal in the scroll rotor, the configurations described in each of the above embodiments can be appropriately adopted.

The rotor for a scroll pump of the present invention can be widely used as a rotor in place of the rotor for a scroll pump made of aluminum because it can reduce stress concentration while reducing the weight and has high versatility.

1 Scroll rotor (rotor for scroll compressor)
2 Board 3 Scroll blade 3a Inner end 3b Outer end 3c Inner wall surface 3d Outer wall surface 3e Tip side end face 4 Arc part 5 Tip arc part 6 Scroll rotor (rotor for scroll compressor)
7 Scroll rotor (rotor for scroll compressor)
8 Fixed rotor 9 Board 10 Fixed side scroll blade 11 Arc part 12 Tip arc part 13 Movable rotor 14 Board 15 Movable side scroll blade 16 Arc part 17 Tip arc part 18 Compression chamber 19 Scroll compressor 21 Scroll rotor (Rotor for scroll compressor)
22 Board 23 Scroll blade 24 Core metal 24a Flange part 24b Wall part 31 Scroll rotor (Rotor for scroll compressor)
32 Board 33 Scroll blade 34 Core metal 34a Flange part 34b Wall part

Claims (14)

A rotor for a scroll compressor having a substantially flat plate-shaped substrate and a spiral scroll blade extending at a substantially right angle from the substrate, forming a compression chamber between the substantially flat plate-shaped substrate and the mating rotor, and compressing the fluid. ,
The rotor for a scroll compressor is configured to include a resin portion.
The scroll blade is composed of the resin portion at the root connected to the substrate, and has an arc portion having an arcuate cross-sectional shape cut along the height direction of the scroll blade, and the arc portion has the arc shape. When the dimension in the height direction of the scroll blade is V and the dimension in the direction perpendicular to the height direction of the scroll blade is H, which is provided in at least a part of the scroll blade, the relational expression of V> H is established. Rotor for scroll compressors characterized by filling. The rotor for a scroll compressor according to claim 1, wherein the dimension V and the dimension H of the arc portion satisfy the relational expression of 1.5 ≦ V / H ≦ 2.5. The scroll compressor according to claim 1 or 2, wherein the resin portion is made of an aromatic polyamide resin, a polyphenylene sulfide resin, a polyetheretherketone resin, a polyetherimide resin, or a liquid crystal polymer as a base resin. Rotor. The rotor for a scroll compressor according to any one of claims 1 to 3, wherein the resin portion contains reinforcing fibers of glass fiber, carbon fiber, or aramid fiber. The rotor for a scroll compressor according to claim 4, wherein the average fiber length of the reinforcing fibers is 0.5 mm or more. The scroll compressor rotor is composed of the resin portion and the core metal, and the core metal is embedded in at least a part of the scroll blade along the spiral shape of the scroll blade. The rotor for a scroll compressor according to any one of items 1 to 5. The scroll blade is characterized in that the core metal is embedded around the winding center of the scroll blade from the central end portion of the scroll blade to a portion of 270 ° or less in the winding direction. 6. The rotor for a scroll compressor according to claim 6. The core metal has a wall portion embedded in the scroll blade and a circular flange portion integrally formed with the wall portion, and the flange portion is embedded in the substrate. 6 or the rotor for a scroll compressor according to claim 7. The rotor for a scroll compressor according to claim 8, wherein the flange portion has a diameter of 90% or more of the hole diameter of the bearing hole provided on the back surface side of the substrate. The rotor for a scroll compressor according to any one of claims 6 to 9, wherein the thickness of the resin portion covering the core metal in the scroll blade is 0.8 mm to 1.5 mm. .. The rotor for a scroll compressor according to any one of claims 6 to 10, wherein the core metal and the resin portion are adhered to each other. The rotor for a scroll compressor according to claim 11, wherein the maximum value of the adhesive gap between the core metal and the resin portion is 0.1 mm or less excluding the adhesive pool portion. The rotor for a scroll compressor according to any one of claims 6 to 12, wherein the core metal is made of a sintered metal material. A fixed rotor having a spiral fixed-side scroll blade erected on the substrate and its surface, and a movable rotor having a spiral movable-side scroll blade erected on the substrate and its surface are provided with the fixed-side scroll blade. A scroll compressor in which a compression chamber is formed between the movable side scroll blade and the movable rotor is revolved around the axis of the fixed rotor to compress gas.
The scroll compressor according to claim 1, wherein at least the movable rotor is the rotor for a scroll compressor according to any one of claims 1.

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