Scroll Compressor

Abstract

To improve durability of scrolls of a scroll-type compressor.SOLUTION: A scroll type compressor 1 includes a fixed scroll 50 and s turning scroll 60 made of an aluminum-based material. A first coating layer C1 by tin plating is formed on a compression chamber side end surface 51a of a base plate 51 and a surface of a spiral wall 52 of one scroll 30A, a second coating layer C2 by nickel-phosphorus plating is formed on a compression chamber side end surface 61a of a base plate 61 and a surface of a spiral wall 62 of the other scroll 30B, and a wall height h2 of the spiral wall 62 of the other scroll 30B is set to be higher than a wall height h1 of the spiral wall 52 of the one scroll 30A. The first coating layer C1 on an end of the spiral wall 52 of the one scroll 30A and the second coating layer C2 on the base plate 61 of the other scroll 30B are separated from each other, and the first coating layer C1 on the base plate 51 of the one scroll 30A and the second coating layer C2 on an end of the spiral wall 62 of the other scroll 30B are brought into contact with each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a scroll compressor used in a vehicle air conditioner or the like. [Background technology]

[0002] The scroll compressor disclosed in Patent Document 1 includes a fixed scroll and an orbiting scroll arranged to mesh with each other, each having a base plate and a spiral wall erected on the base plate, and is configured to compress a fluid taken into a compression chamber formed between the fixed scroll and the orbiting scroll by revolving the orbiting scroll relative to the fixed scroll. In the scroll compressor disclosed in Patent Document 1, the fixed scroll and the orbiting scroll are made of an aluminum-based material to reduce weight, and a coating layer made of nickel-phosphorus plating is formed on the surfaces of the base plate and spiral wall of the orbiting scroll. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2941680 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the scroll compressor disclosed in Patent Document 1, the fixed scroll is not plated, and the aluminum-based material is exposed on the surface of the fixed scroll, so there is a risk that the nickel-phosphorus plating coating layer on the tip of the spiral wall of the orbiting scroll will directly slide against the aluminum-based material of the base plate of the fixed scroll. Furthermore, because the mutual solubility of nickel and aluminum is relatively high, in the scroll compressor disclosed in Patent Document 1, for example, there is a risk that the tip of the spiral wall of the orbiting scroll will adhere to the aluminum-based base plate of the fixed scroll through the nickel-containing coating layer, leaving room for improvement in terms of durability.

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a scroll compressor having a structure that can reduce the weight of each scroll while improving durability. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a scroll compressor including a fixed scroll and an orbiting scroll arranged to mesh with each other, each having a base plate and a spiral wall extending from the base plate, and configured to compress a fluid taken into a compression chamber formed between the fixed scroll and the orbiting scroll by revolving the orbiting scroll relative to the fixed scroll. In this scroll compressor, each of the fixed scroll and the orbiting scroll is made of an aluminum-based material, and a first coating layer formed by tin plating is formed on a compression chamber side end face of the base plate of one of the fixed scroll and the orbiting scroll and on a surface of the spiral wall of the one scroll, and a second coating layer formed by nickel-phosphorus plating is formed on a compression chamber side end face of the base plate of the other of the fixed scroll and the orbiting scroll and on a surface of the spiral wall of the other scroll. The wall height of the spiral wall of the other scroll is set to be higher than the wall height of the spiral wall of the one scroll, the first coating layer on the tip of the spiral wall of the one scroll and the second coating layer on the substrate of the other scroll are spaced apart from each other, and the first coating layer on the substrate of the one scroll and the second coating layer on the tip of the spiral wall of the other scroll are in contact with each other. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a scroll compressor having a structure that can reduce the weight of each scroll while improving durability. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a scroll compressor according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view illustrating a main part of the scroll compressor. [Figure 3] FIG. 2 is an enlarged cross-sectional view of a compressor according to a comparative example. [Figure 4]FIG. 10 is an enlarged cross-sectional view of a compressor according to another comparative example. [Figure 5] FIG. 10 is an enlarged cross-sectional view of a main portion for explaining a modified example of the scroll compressor. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] Fig. 1 is a cross-sectional view showing a schematic configuration of a scroll compressor 1 according to one embodiment of the present invention. The scroll compressor 1 is incorporated into a refrigerant circuit of a vehicle air conditioner or the like, and is configured to receive low-pressure gaseous refrigerant from the refrigerant circuit, compress it, increase the pressure, and return it to the refrigerant circuit. Note that Fig. 1 shows an example of the front-rear direction and the up-down direction when the scroll compressor 1 is in use. The aforementioned gaseous refrigerant is an example of a fluid in the present invention.

[0011] The scroll compressor 1 includes a housing 10, a rotating shaft 20a, an electric motor 20 that rotates the rotating shaft 20a, a scroll unit 30 that is driven by the rotating shaft 20a and compresses a (low-pressure) gaseous refrigerant, and an inverter 40 that drives and controls the electric motor 20. Main components (10, 20a, 30, 40) are housed inside the housing 10. The scroll unit 30 includes a fixed scroll 50 and an orbiting scroll 60. The fixed scroll 50 and the orbiting scroll 60 are arranged opposite to each other in the central axial direction of the scroll compressor 1 and are meshed with each other.

[0012] The housing 10 includes a front housing 11, a cover member 12, a center housing 13, and a rear housing 14. These components (11, 12, 13, 14) are fastened together by fasteners (not shown) or the like to form the housing 10 of the scroll compressor 1.

[0013] The front housing 11 has a cylindrical first peripheral wall portion 111 and a first partition portion 112 that divides the interior of the first peripheral wall portion 111 into a front and a rear space. The interior space of the first peripheral wall portion 111 is divided by the first partition portion 112 into an inverter-accommodating space on the front side and a motor-accommodating space on the rear side. The first partition portion 112 is provided with a support portion 113 that supports the front end of the rotating shaft 20a, and the support portion 113 rotatably supports the front end of the rotating shaft 20a via a first bearing 114.

[0014] The cover member 12 is joined to the front end surface of the front housing 11, thereby closing off the inverter accommodating space. The front end surface of the center housing 13 is joined to the rear end surface of the front housing 11.

[0015] The center housing 13 has a cylindrical second circumferential wall portion 131 and a second partition wall portion 132 that divides the interior of the second circumferential wall portion 131 into a front and a rear space. The internal space of the second circumferential wall portion 131 is divided by the second partition wall portion 132 into a front connection space connected to the motor accommodating space and a rear scroll accommodating space. The second partition wall portion 132 has a hollow protrusion portion 132a that protrudes toward the front housing 11. A rotary shaft insertion hole 132b is formed in the hollow protrusion portion 132a. The hollow protrusion portion 132a rotatably supports a rear end portion of the rotary shaft 20a via a second bearing 133.

[0016] The rear housing 14 is joined to the rear end surface of the center housing 13. For example, a recess 134 is formed in the rear end surface of the center housing 13 (second circumferential wall portion 131). The outer edge of the fixed scroll 50 is sandwiched between the center housing 13 and the rear housing 14, and the rear opening of the second circumferential wall portion 131 is closed by the fixed scroll 50. The rear housing 14 has a cylindrical third circumferential wall portion 141 and a bottom wall portion 142 that closes the rear opening of the third circumferential wall portion 141. The front end surface of the third circumferential wall portion 141 is joined to the rear end surface of the second circumferential wall portion 131, and the front opening of the third circumferential wall portion 141 is closed by the fixed scroll 50.

[0017] The electric motor 20 is configured as, for example, a three-phase AC motor and includes a stator core unit 21 and a rotor 22. The stator core unit 21 is fixed to the inner circumferential surface of the first circumferential wall portion 111 of the front housing 11. DC current from an on-board battery (not shown) or the like is converted into AC current by an inverter 40 and supplied to the stator core unit 21. The rotor 22 is disposed radially inside the stator core unit 21 with a predetermined gap therebetween. The rotor 22 is formed in a cylindrical shape and is fixed to the rotating shaft 20a with the rotating shaft 20a inserted into its hollow portion. The rotor 22 is integrated with the rotating shaft 20a.

[0018] When a magnetic field is generated in the stator core unit 21 by power supply from the inverter 40, a rotational force acts on the permanent magnets incorporated in the rotor 22, causing the rotor 22 to rotate, thereby rotating the rotary shaft 20a.

[0019] As described above, the scroll unit 30 includes the fixed scroll 50 and the orbiting scroll 60 that revolves around the fixed scroll 50. The fixed scroll 50 and the orbiting scroll 60 are arranged to mesh with each other, and each have a base plate (51, 61) and a spiral-shaped spiral wall (52, 62) standing on the base plate (51, 61). Each of the fixed scroll 50 and the orbiting scroll 60 is made of an aluminum-based material. Specifically, an aluminum alloy is used as the material for each scroll (50, 60), thereby reducing the weight of the scroll unit 30.

[0020] Specifically, the fixed scroll 50 has a disk-shaped base plate 51 (hereinafter referred to as the fixed base plate 51 as appropriate) and a spiral-shaped spiral wall 52 (hereinafter referred to as the fixed spiral wall 52 as appropriate) erected on the compression chamber side end face 51a of the fixed base plate 51. The orbiting scroll 60 has a disk-shaped base plate 61 (hereinafter referred to as the orbiting base plate 61 as appropriate) and a spiral wall 62 (hereinafter referred to as the orbiting spiral wall 62 as appropriate) erected on the compression chamber side end face 61a of the orbiting base plate 61. The orbiting scroll 60 is arranged so that the orbiting spiral wall 62 meshes with the fixed spiral wall 52 of the fixed scroll 50. The orbiting scroll 60 is driven by the rotating shaft 20a via a crank mechanism 70 and is configured to perform an orbital motion relative to the fixed scroll 50.

[0021] The crank mechanism 70 connects the rotary shaft 20a and the orbiting scroll 60 and converts the rotational motion of the rotary shaft 20a into the orbital motion of the orbiting scroll 60. The crank mechanism 70 includes a crank pin 71 erected at the rear end of the rotary shaft 20a, an eccentric bushing 72 attached eccentrically to the crank pin 71, and a cylindrical portion 73 formed to protrude from the rear surface of the orbiting base plate 61 of the orbiting scroll 60. The eccentric bushing 72 is rotatably supported on the inner circumferential surface of the cylindrical portion 73 via a bearing (not shown). A balancer weight 74 is attached to the rear end of the rotary shaft 20a.

[0022] The rotation of the orbiting scroll 60 can be prevented by a rotation-preventing mechanism 80. The rotation-preventing mechanism 80 is configured by arranging a plurality of rotation-preventing portions, each composed of a ring 81 and a pin 82, at equal intervals along the circumferential direction near the outer periphery of the back surface of the orbiting base plate 61. The ring 81 is press-fitted into a circular hole formed in the back surface 61b, which is the surface of the orbiting base plate 61 opposite to the compression chamber-side end surface 61a, and the pin 82 protrudes from the second partition wall portion 132 of the center housing 13, passes through the thrust plate 90, and is loosely fitted inside the ring 81.

[0023] The scroll unit 30 is configured so that the orbiting scroll 60 takes in and compresses a low-pressure gaseous refrigerant by revolving around the fixed scroll 50. A circular annular thrust plate 90 is disposed between the orbiting base plate 61 of the orbiting scroll 60 and the second partition wall portion 132 of the center housing 13, and the rear surface of the second partition wall portion 132 receives the thrust force from the orbiting scroll 60 via the thrust plate 90.

[0024] Here, the scroll compressor 1 has a suction chamber H1 into which low-pressure gas refrigerant flows, a compression chamber H2 that compresses the low-pressure gas refrigerant, a discharge chamber H3 from which the gas refrigerant compressed in the compression chamber H2 is discharged, a gas-liquid separation chamber H4 that separates lubricating oil from the gas refrigerant compressed in the compression chamber H2, and a back pressure chamber H5 provided on the back side of the rotating scroll 60 (the back side of the rotating base plate 61).

[0025] The suction chamber H1 is defined by the front housing 11 (first peripheral wall 111, first partition 112) and the center housing 13 (second peripheral wall 131, second partition 132). An intake port P1 formed in the first peripheral wall 111 is connected to the refrigerant circuit (the low-pressure side thereof) via a connecting pipe (not shown). Therefore, low-pressure refrigerant from the refrigerant circuit flows into the suction chamber H1 through the intake port P1. In addition, a refrigerant passage L1 is formed in the center housing 13 to guide the low-pressure gas refrigerant in the suction chamber H1 to a space H6 near the outer end of the scroll unit 30.

[0026] The compression chamber H2 is formed between the fixed scroll 50 and the orbiting scroll 60. The scroll unit 30 is configured to compress the low-pressure gaseous refrigerant by taking in the low-pressure gaseous refrigerant from the space H6 when the compression chamber H2 is formed. The scroll compressor 1 is configured to compress the gaseous refrigerant (fluid) taken in the compression chamber H2 formed between the fixed scroll 50 and the orbiting scroll 60 by revolving the orbiting scroll 60 relative to the fixed scroll 50.

[0027] The discharge chamber H3 is formed by the rear housing 14 (third circumferential wall portion 141, bottom wall portion 142) and the fixed scroll 50 (fixed base plate 51). The gaseous refrigerant compressed in the compression chamber H2 is discharged into the discharge chamber H3 through a discharge hole L2 formed in the radial center of the fixed base plate 51. A check valve V, such as a reed valve, is attached to a surface 51b opposite to the compression chamber-side end surface 51a of the fixed base plate 51 of the fixed scroll 50. The check valve V allows the gaseous refrigerant to flow from the compression chamber H2 to the discharge chamber H3 but restricts the flow of the gaseous refrigerant from the discharge chamber H3 to the compression chamber H2.

[0028] The gas-liquid separation chamber H4 is provided in the rear housing 14. For example, a centrifugal oil separator OS is disposed within the gas-liquid separation chamber H4. A discharge port P2 provided above the oil separator OS is connected to the refrigerant circuit (the high-pressure side thereof) via a connecting pipe (not shown). The gas refrigerant (high-pressure gas refrigerant) within the discharge chamber H3 flows into the gas-liquid separation chamber H4 through a communication hole L3 formed in the bottom wall portion 142 of the rear housing 14, where the lubricating oil contained in the gas refrigerant is separated by the oil separator OS and then discharged from the discharge port P2 to the high-pressure side of the refrigerant circuit. Meanwhile, the lubricating oil separated from the high-pressure gas refrigerant by the oil separator OS is guided by gravity to the bottom of the gas-liquid separation chamber H4.

[0029] The back pressure chamber H5 is formed between the swivel base plate 61 and the second partition wall 132. In this embodiment, the back pressure chamber H5 includes the internal space of the hollow protrusion 132a of the second partition wall 132. A lubricant oil passage L4 connecting the back pressure chamber H5 and the gas-liquid separation chamber H4 is formed in the center housing 13, the fixed base plate 51, and the rear housing 14. An orifice (throttle portion) OL is disposed in the lubricant oil passage L4. In the gas-liquid separation chamber H4, the lubricant oil separated by the oil separator OS is depressurized by the orifice OL and supplied to the back pressure chamber H5 through the lubricant oil passage L4. The back pressure chamber H5 can communicate with the compression chamber H2 via a through hole 611 formed in the swivel base plate 61 and functioning as a throttle portion. Therefore, the through hole 611 limits the flow rate of the fluid (lubricant oil and / or gas refrigerant) passing between the back pressure chamber H5 and the compression chamber H2. As a result, the pressure in the back pressure chamber H5 is maintained at an intermediate pressure (back pressure) between the pressure in the suction chamber H1 and the pressure in the discharge chamber H3, and this intermediate pressure (back pressure) presses the orbiting scroll 60 against the fixed scroll 50. In other words, the back pressure chamber H5 applies a back pressure (back pressure load) to the orbiting scroll 60 that presses the orbiting scroll 60 against the fixed scroll 50.

[0030] To improve the durability of the scroll unit 30, it is possible to apply tin plating (hereinafter referred to as Sn plating) or nickel-phosphorus plating (hereinafter referred to as Ni-P plating). Sn plating has excellent lubricity, conforms well to other materials, and is easily able to improve the critical surface pressure (specifically, the surface pressure at which seizure occurs when a material slides against another material at a predetermined sliding speed). Furthermore, the application cost of Sn plating is generally lower than that of Ni-P plating. However, compared to Ni-P plating, Sn plating is more susceptible to wear and peeling from the plated surface. Furthermore, Sn plating has inferior heat resistance compared to Ni-P plating. Therefore, if the same Sn-plated area slides continuously for a long period of time, the Sn plating may be worn away from the plated surface due to wear or peeling, potentially exposing the plated surface. Furthermore, Ni-P plating has superior heat resistance compared to Sn plating. However, nickel and aluminum have a relatively high mutual solubility. The inventors of the present application took note of this high mutual solubility and realized that direct contact of the Ni-P plating with the aluminum-based material of the scroll unit 30 is not a desirable sliding state.

[0031] The scroll compressor 1 according to this embodiment has the following structure for improving the durability of the scroll unit 30 while reducing the weight of the scroll unit 30.

[0032] FIG. 2 is an enlarged cross-sectional view of the scroll compressor 1 for explaining the main parts thereof.

[0033] In the scroll unit 30 of the scroll compressor 1 according to this embodiment, a first coating layer C1 made of tin plating is formed on the compression chamber side end face (51a or 61a) of the base plate (51 or 61) of one scroll 30A of the fixed scroll 50 and the orbiting scroll 60, and on the surface of the spiral wall (52 or 62) of the one scroll 30A. The first coating layer C1 (in other words, an Sn-plated layer) has a first layer thickness t1, which is a predetermined plating thickness, and the plated portion of the one scroll 30A is covered with the first coating layer C1 (Sn-plated layer) made of, for example, electroless Sn and having the first layer thickness t1.

[0034] A second coating layer C2 made of nickel-phosphorus plating is formed on the compression chamber side end surface (61a or 51a) of the base plate (61 or 51) of the other scroll 30B of the fixed scroll 50 and the orbiting scroll 60, and on the surface of the spiral wall (62 or 52) of the other scroll 30B. The second coating layer C2 (in other words, the Ni-P plating layer) has a second layer thickness t2, which is a predetermined plating thickness, and the plated portions of the other scroll 30B are covered with the second coating layer C2 (Ni-P plating layer) having the second layer thickness t2.

[0035] That is, in the scroll unit 30, the compression chamber side end surface 51a of the fixed base plate 51 and the fixed spiral wall 52 of the fixed scroll 50, and the compression chamber side end surface 61a of the orbiting base plate 61 and the orbiting spiral wall 62 of the orbiting scroll 60 are plated.

[0036] In this embodiment, the plating area of ​​the orbiting scroll 60 is smaller than the plating area of ​​the fixed scroll 50. Specifically, the orbiting base plate 61 of the orbiting scroll 60 has an outer shape smaller than the outer shape of the fixed base plate 51 of the fixed scroll 50. The plating area of ​​the orbiting scroll 60, which is obtained by adding together the surface area of ​​the compression chamber side end face 61a of the orbiting base plate 61 and the surface area of ​​the orbiting spiral wall 62, is smaller than the plating area of ​​the fixed scroll 50, which is obtained by adding together the surface area of ​​the compression chamber side end face 51a of the fixed base plate 51 and the surface area of ​​the fixed spiral wall 52.

[0037] In this embodiment, one scroll 30A on which the first coating layer C1 by tin plating is formed is the fixed scroll 50, and the other scroll 30B on which the second coating layer C2 by nickel-phosphorus plating is formed is the orbiting scroll 60. In other words, one scroll 30A on which the first coating layer C1 by tin plating is formed is the fixed scroll 50, and the other scroll 30B on which the second coating layer C2 by nickel-phosphorus plating is formed is the orbiting scroll 60.

[0038] Therefore, in this embodiment, the first coating layer C1 made of tin plating is formed on the compression chamber side end face 51a of the fixed base plate 51 and the surface of the fixed spiral wall 52 of the fixed scroll 50 serving as one of the scrolls 30A. In other words, in this embodiment, the first coating layer C1 (Sn plating layer) is formed on the fixed scroll 50 having a relatively large (wide) plating area out of the fixed scroll 50 and the orbiting scroll 60.

[0039] In this embodiment, the second coating layer C2 made of nickel-phosphorus plating is formed on the compression chamber side end surface 61a of the orbiting base plate 61 and the surface of the orbiting spiral wall 62 of the orbiting scroll 60 serving as the other scroll 30B. In other words, in this embodiment, the second coating layer C2 (Ni-P plating layer) is formed on the orbiting scroll 60 having the relatively small (narrow) plating area between the fixed scroll 50 and the orbiting scroll 60.

[0040] 2, a wall height h2 of the spiral wall of the other scroll 30B (in this embodiment, the orbiting spiral wall 62) is set higher than a wall height h1 of the spiral wall of one scroll 30A (in this embodiment, the fixed spiral wall 52). Specifically, the wall height h2 of the orbiting spiral wall 62 is the distance from the compression chamber side end face 61a of the orbiting base plate 61 to the tip face of the orbiting spiral wall 62, and the wall height h1 of the fixed spiral wall 52 is the distance from the compression chamber side end face 51a of the fixed base plate 51 to the tip face of the fixed spiral wall 52.

[0041] The first coating layer C1 (Sn plating layer) on the tip of the spiral wall (fixed spiral wall 52) of one scroll 30A and the second coating layer C2 (Ni-P plating layer) on the substrate (orbiting substrate 61) of the other scroll 30B are spaced apart from each other, and the first coating layer C1 (Sn plating layer) on the substrate (fixed substrate 51) of one scroll 30A and the second coating layer C2 (Ni-P plating layer) on the tip of the spiral wall (orbiting spiral wall 62) of the other scroll 30B are in contact with each other. Therefore, during scroll operation, the first coating layer C1 (Sn plating layer) on the tip of the spiral wall of one scroll 30A is always spaced apart from the opposing second coating layer C2 (Ni-P plating layer) on the substrate of the other scroll 30B. In contrast, the second coating layer C2 (Ni-P plated layer) on the tip of the spiral wall of the other scroll 30B slides against the first coating layer C1 (Sn plated layer) on the substrate of one scroll 30A.

[0042] Next, the effects of the scroll compressor 1 according to this embodiment will be described in comparison with a comparative scroll compressor according to a comparative example. FIGS. 3 and 4 are enlarged cross-sectional views of comparative scroll compressors (1', 1"), respectively, for comparison with the scroll compressor 1 of this embodiment shown in FIG. 2. FIG. 3 is an enlarged cross-sectional view of the scroll unit 30 of the comparative compressor 1' according to the comparative example, and FIG. 4 is an enlarged cross-sectional view of the scroll unit 30 of the comparative compressor 1" according to another comparative example.

[0043] 3, in the comparative compressor 1' according to the comparative example, a second coating layer C2 made of nickel-phosphorus is formed on the compression-chamber-side end surface 61a of the orbiting base plate 61 of the orbiting scroll 60 and on the surface of the orbiting spiral wall 62, but the fixed scroll 50 is not plated. Furthermore, the tip of the fixed spiral wall 52 of the fixed scroll 50, where the aluminum-based material (base material) is exposed, is in contact with the second coating layer C2 (Ni-P plating layer) formed on the compression-chamber-side end surface 61a of the orbiting base plate 61. Therefore, in the comparative compressor 1' according to the comparative example, during scroll operation, the tip of the orbiting spiral wall 62 directly contacts and slides against the exposed compression-chamber-side end surface 51a of the fixed scroll 50, which contains an aluminum component, via the second coating layer C2 containing a nickel component. Furthermore, because the nickel component and the aluminum component have high mutual solubility, in the comparative compressor 1', a large amount of frictional heat is generated at the sliding portion between the tip of the orbiting spiral wall 62 of the orbiting scroll 60 (the surface of the second coating layer C2) and the compression-chamber-side end face 51a of the fixed base plate 51 of the fixed scroll 50, which may cause the temperature of the sliding portion to rise excessively. In this case, in the comparative compressor 1', there is a risk that the tip of the orbiting spiral wall 62 of the orbiting scroll 60 will adhere to the compression-chamber-side end face 51a of the exposed aluminum-containing fixed base plate 51 of the fixed scroll 50 via the second coating layer C2 containing nickel. Similarly, in the comparative compressor 1', there is a risk that the tip of the exposed aluminum-containing fixed spiral wall 52 of the fixed scroll 50 will adhere to the compression-chamber-side end face 61a of the orbiting base plate 61 of the orbiting scroll 60 via the second coating layer C2 containing nickel. In other words, in the comparative compressor 1', the second coating layer C2 (Ni-P plating layer) containing nickel components applied to the orbiting scroll 60 slides in direct contact with the exposed aluminum-based material (aluminum raw material) of the fixed scroll 50, which may cause adhesion between the two scrolls (50, 60).

[0044] In contrast, in the scroll compressor 1 according to this embodiment, a first coating layer C1 made of tin plating is formed on the compression chamber side end face of the base plate of one scroll 30A and the surface of the spiral wall, and a second coating layer C2 made of nickel-phosphorus plating is formed on the compression chamber side end face of the base plate of the other scroll 30B and the surface of the spiral wall. Therefore, in the scroll compressor 1, the second coating layer C2 (Ni-P plating layer) containing nickel and applied to the other scroll 30B is prevented from sliding in contact with the aluminum-based material (aluminum raw material) of one scroll 30A.

[0045] Referring to FIG. 4, in a comparative compressor 1″ according to another comparative example, a second coating layer C2 made of nickel-phosphorus is formed on the compression chamber side end face 61 a of the orbiting base plate 61 of the orbiting scroll 60 and on the surface of the orbiting spiral wall 62, and a first coating layer C1 made of tin plating is formed on the compression chamber side end face 51 a of the fixed base plate 51 of the fixed scroll 50 and on the surface of the fixed spiral wall 52. In the comparative compressor 1″, the first coating layer C1 (Sn plating layer) on the compression chamber side end face 51 a of the fixed base plate 51 of the fixed scroll 50 and the second coating layer C2 (Ni-P plating layer) on the tip of the orbiting spiral wall 62 of the orbiting scroll 60 are in contact with each other. In these respects, the structure of the comparative compressor 1" is common to the structure of the scroll compressor 1 according to this embodiment. However, in the comparative compressor 1", the first coating layer C1 (Sn plating layer) on the tip of the fixed spiral wall 52 of the fixed scroll 50 and the second coating layer C2 (Ni-P plating layer) on the compression chamber side end face 61a of the orbiting base plate 61 of the orbiting scroll 60 are in contact with each other.

[0046] Here, in the comparative compressor 1", the wall height of the fixed spiral wall 52 of the fixed scroll 50 is the same as the wall height of the orbiting spiral wall 62 of the orbiting scroll 60. During scroll operation of the comparative compressor 1", temperature increases due to frictional heat occur in each of the following contact pairs A and B. Contact pair A is a sliding portion between the first coating layer C1 (Sn plated layer) on the tip of the fixed spiral wall 52 of the fixed scroll 50 and the second coating layer C1 (Ni-P plated layer) on the compression chamber side end face 61a of the orbiting base plate 61 of the orbiting scroll 60. Contact pair B is a sliding portion between the first coating layer C1 (Sn plated layer) on the compression chamber side end face 51a of the fixed base plate 51 of the fixed scroll 50 and the second coating layer C2 (Ni-P plated layer) on the tip of the orbiting spiral wall 62 of the orbiting scroll 60.

[0047] As mentioned above, Sn plating is more susceptible to wear and peeling from the plated surface than Ni-P plating. Therefore, the inventors of the present application conducted a detailed study on the sliding state of the first coating layer C1 (Sn plating layer) in contact pair A and contact pair B of the comparative compressor 1".

[0048] In the comparative compressor 1", in contact pair B, during scroll operation, the first coating layer C1 (Sn plated layer) on the compression chamber side end face 51a of the fixed base plate 51 of the fixed scroll 50 intermittently slides against the second coating layer C2 due to the orbital revolution of the orbiting scroll 60. Therefore, with the intermittent sliding, the first coating layer C1 (Sn plated layer) on the compression chamber side end face 51a of the fixed base plate 51 in contact pair B is less likely to wear or peel off, and the first coating layer C1 (Sn plated layer) is more likely to remain.

[0049] However, in the comparative compressor 1", in the contact pair A, the first coating layer C1 (Sn plating layer) on the tip of the fixed spiral wall 52 of the fixed scroll 50 continuously (always) slides on the second coating layer C2 during scroll operation. Therefore, in the contact pair A, the first coating layer C1 (Sn plating layer) on the tip of the fixed spiral wall 52 of the fixed scroll 50 may be worn away and peeled off from the tip of the fixed spiral wall 52, and the aluminum-based material (aluminum raw material) may be exposed on the tip surface of the fixed spiral wall 52. As a result, the fixed spiral wall 52 may be heated. When stretched due to expansion, a large frictional force is generated between the aluminum-based material exposed at the tip end surface of the fixed spiral wall 52 and the surface of the second coating layer C2 (Ni-P plating layer) on the compression-chamber-side end surface 61a of the orbiting base plate 61, which may cause an excessive rise in temperature. In this case, in the comparative compressor 1", in contact pair A, the tip end of the exposed fixed spiral wall 52 containing an aluminum component of the fixed scroll 50 may adhere to the compression-chamber-side end surface 61a of the orbiting base plate 61 of the orbiting scroll 60 via the second coating layer C2 containing a nickel component.

[0050] In contrast, in the scroll compressor 1 according to this embodiment, the first coating layer C1 (Sn-plated layer) on the tip of the spiral wall of one scroll 30A and the second coating layer C2 on the base plate of the other scroll 30B, which constitute pair A1 corresponding to contact pair A, are spaced apart from each other. Therefore, in the scroll compressor 1, the first coating layer C1 (Sn-plated layer) on the tip of the spiral wall of one scroll 30A is prevented from wearing and peeling off. As a result, in the scroll compressor 1, the tip of the spiral wall of one scroll 30A is reliably prevented from adhering to the second coating layer C2 on the compression-chamber-side end face of the base plate of the other scroll 30B, thereby improving durability.

[0051] In the scroll compressor 1, a gap is formed between the first coating layer C1 (Sn plated layer) on the tip of the spiral wall of one scroll 30A and the second coating layer C2 on the base plate of the other scroll 30B, so that the first coating layer C1 (Sn plated layer) on the compression chamber side end face of the base plate of one scroll 30A and the second coating layer C2 on the tip of the spiral wall of the other scroll 30B come into preferential contact with each other. As a result, in the scroll compressor 1, the pressing force in pair A1 corresponding to contact pair A (the first coating layer C1 (Sn plated layer) on the tip of the spiral wall of one scroll 30A and the second coating layer C2 on the base plate of the other scroll 30B) is reduced compared to the pressing force in the comparative compressor 1'', and the pressing force in pair B1 corresponding to contact pair B (the first coating layer C1 (Sn plated layer) on the compression chamber side end surface of the base plate of one scroll 30A and the second coating layer C2 on the tip of the spiral wall of the other scroll 30B) is increased compared to the pressing force in the comparative compressor 1''. The pressing force increases in pair B1 corresponding to contact pair B in the scroll compressor 1, but the first coating layer C1 (Sn plated layer) on the compression chamber side end surface of the base plate of one scroll 30A of this pair B1 slides intermittently against the second coating layer C2. Therefore, the first coating layer C1 (Sn plating layer) of this pair B1 is more likely to remain and has a high critical surface pressure.

[0052] In addition, in this embodiment, the scroll compressor 1 is configured such that the gaseous refrigerant is taken into the compression chamber H2 together with the lubricating oil, and an oil film M made of the lubricating oil is formed in the gap between the first coating layer C1 at the tip of the spiral wall of one scroll 30A and the second coating layer C2 on the base plate of the other scroll 30B. This easily ensures the airtightness of the compression chamber H2 while improving the wear resistance and adhesion (galling) resistance. As a result, the life of the Sn plating (first coating layer C1) is extended, and ultimately, durability is more effectively improved.

[0053] As described above, in the scroll compressor 1 according to this embodiment, the weight of the scroll unit 30 is reduced by using an aluminum-based material as the material for the fixed scroll 50 and the orbiting scroll 60. As described above, the scroll compressor 1 has a structure that can improve durability compared to conventional scroll compressors.

[0054] In this embodiment, the plating area of ​​the orbiting scroll 60 is smaller than the plating area of ​​the fixed scroll 50, and the other scroll 30B on which the second coating layer C2 made of nickel-phosphorus plating (Ni-P plating) is formed is the orbiting scroll 60. As a result, the Ni-P plating, which has a high plating cost per unit area, is formed on the orbiting scroll 60, which has a small (narrow) plating area. As a result, the plating cost is lower than the plating cost when the second coating layer C2 (Ni-P plating layer) is formed on the fixed scroll 50, and manufacturing costs are reduced.

[0055] In this embodiment, the other scroll 30B to be plated with nickel-phosphorus is the orbiting scroll 60, but is not limited to this. As shown in FIG. 5, the other scroll 30B to be plated with nickel-phosphorus may be the fixed scroll 50.

[0056] Specifically, referring to FIG. 5, in the scroll unit 30 of the scroll compressor 1 according to the modified example, the other scroll 30B on which the second coating layer C2 made of nickel-phosphorus plating is formed is the fixed scroll 50, and the other scroll 30A on which the first coating layer C1 made of tin plating (Sn plating) is formed is the orbiting scroll 60. In this case, referring to Figure 5, a first coating layer C1 made of tin plating is formed on the compression chamber side end face 61a of the orbiting base plate 61 of the orbiting scroll 60 and the surface of the orbiting spiral wall 62, and a second coating layer C2 made of nickel-phosphorus plating is formed on the compression chamber side end face 51a of the fixed base plate 51 of the fixed scroll 50 and the surface of the fixed spiral wall 52, and the wall height h2 of the fixed spiral wall 52 of the fixed scroll 50, which is the other scroll 30B, on which the nickel-phosphorus plating (Ni-P plating) is formed, is set to be higher than the wall height h1 of the orbiting spiral wall 62 of the orbiting scroll 60, which is one scroll 30A, on which the tin plating is formed. 5, the first coating layer C1 on the tip of the orbiting spiral wall 62 of the orbiting scroll 60 and the second coating layer C2 on the fixed base plate 51 of the fixed scroll 50 are spaced apart from each other, and the first coating layer C1 on the orbiting base plate 61 of the orbiting scroll 60 and the second coating layer C2 on the tip of the fixed spiral wall 52 of the fixed scroll 50 are in contact with each other. In the scroll compressor 1 according to this modification, the weight of the scroll unit 30 is reduced and durability is improved.

[0057] The description of the present embodiment is merely an example for explaining the present invention, and does not limit the invention described in the claims. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims. [Explanation of symbols]

[0058] 1...Scroll compressor, 50...Fixed scrolling, 51...Fixed substrate (substrate), 51a...compression chamber side end surface, 52...Fixed spiral wall (spiral wall), 60...Swivel scroll, 61... Swivel base plate (base plate), 61a compression chamber side end surface, 62...Swirling spiral wall (spiral wall), 30A...One scroll, 30B...the other scroll, C1...first coating layer, C2...second coating layer, h1...wall height (wall height of the spiral wall of the one scroll), h2...wall height (wall height of the spiral wall of the other scroll), H2...Compression chamber

Claims

1. A scroll-type compressor including a fixed scroll and an orbiting scroll arranged to mesh with each other and each having a base plate and a spiral wall erected on the base plate, wherein the orbiting scroll is revolved around the fixed scroll to compress a fluid taken into a compression chamber formed between the fixed scroll and the orbiting scroll, each of the fixed scroll and the orbiting scroll is made of an aluminum-based material; a first coating layer formed by tin plating is formed on a compression chamber side end surface of the base plate of one of the fixed scroll and the orbiting scroll and on a surface of the spiral wall of the one scroll; a second coating layer formed by nickel-phosphorus plating is formed on the compression chamber side end surface of the base plate of the other scroll of the fixed scroll and the orbiting scroll and on the surface of the spiral wall of the other scroll; a wall height of the spiral wall of the other scroll is set to be higher than a wall height of the spiral wall of the one scroll, the first coating layer on the tip of the spiral wall of the one scroll and the second coating layer on the base plate of the other scroll are spaced apart from each other; the first coating layer on the substrate of the one scroll and the second coating layer on the tip of the spiral wall of the other scroll are in contact with each other, a plating area of ​​the orbiting scroll is smaller than a plating area of ​​the fixed scroll, The other scroll on which the second coating layer formed by nickel-phosphorus plating is the orbiting scroll.

2. the fluid is a gaseous refrigerant; 2. The scroll compressor according to claim 1, wherein the gaseous refrigerant is taken into the compression chamber together with lubricating oil, and an oil film made of the lubricating oil is formed in a gap between the first coating layer on the tip of the spiral wall of the one scroll and the second coating layer on the base plate of the other scroll.

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