JPWO2011104876A1 - Scroll compressor - Google Patents

Abstract

The present invention provides a scroll compressor that contributes to the reduction in size and weight of the whole, is excellent in durability and reliability, and can be operated at an ultra high speed by applying a new refrigerant. In this scroll compressor, the base material of the Oldham ring 107 is made of an aluminum alloy, and a hard DLC layer is formed by interposing an undercoat layer on the surface of which an adhesiveness is good and supplements hardness. The weight of the rotating system is reduced by about 1/3 of the weight of the iron-based material, which prevents adhesive wear between sliding members, improves wear resistance, and lowers the friction coefficient. It is small. Moreover, the orbiting scroll 101 has a similar material structure, thereby reducing the eccentric mass of the rotating system. As a result, the torque load of the motor 100 can be reduced as much as possible, contributing to the overall downsizing and weight reduction, excellent durability and reliability, and enabling ultra-high speed operation using a new refrigerant, The compression performance equivalent to the case of using chlorofluorocarbon is obtained. [Selection] Figure 1

Description

  INDUSTRIAL APPLICABILITY The present invention is suitable as a compressor for a refrigeration / air conditioning circuit in an air-conditioning hot-water supply system for a new generation house having a high eco (environmentally friendly) effect, and is applied with a new refrigerant having a low global warming potential (GWP). The present invention relates to a scroll compressor having a miniaturized and lightened structure that can be operated in a wide range at a motor system drive signal frequency, and is particularly excellent in durability and reliability in ultra-high speed operation.

  Conventionally, scroll compressors used in refrigeration / air conditioning circuits (also referred to as refrigerant cycles) of air conditioners and refrigerators are generally used for Oldham rings and orbiting scrolls, which are sliding members that increase slidability during operation. For this, a hard and highly wear-resistant iron-based material is used.

  By the way, chlorofluorocarbon, which has been used for general purposes as a refrigerant for refrigeration and air conditioning circuits, has a high global warming potential (GWP) and has a risk of destroying the ozone layer. Tend to. For this reason, recently, a new refrigerant with a low global warming potential (GWP) has been used. However, the new refrigerant does not have an excellent heat exchange rate compared to Freon, and the conventional compressor has the same compression. In order to obtain performance, it is necessary to increase the volume of the entire compressor or drive the crankshaft (rotary main shaft) to rotate at a high speed as an ultra-high speed operation.

  However, measures to increase the overall volume of the compressor structurally lead to an increase in the size of the entire compressor, and measures to rotate the crankshaft (rotating main shaft) at a high speed increase the torque load of the motor and increase the driving side. In this case, it is necessary to reduce the size, weight, and cost of these devices in any case. There are circumstances that cannot be said to be a good idea because it would be against the current demands. In addition, for new refrigerants, it is necessary to improve the wear resistance and lower the coefficient of friction in the sliding member of the internal structure of the compressor than when using chlorofluorocarbon.

  Therefore, the structural improvement of the compressor or the improvement of the electric circuit system is not performed, the material of the internal structure of the compressor is devised, and a certain degree of operation performance is ensured even if a new refrigerant is used. Techniques for improving wear resistance and reducing the friction coefficient of members have also been proposed.

  For example, even when an alternative refrigerant or natural refrigerant not containing chlorine is used, a scroll-type electric compressor using a sliding member that can further improve wear resistance and can be free of long-term maintenance (see Patent Document 1), configuration A compressor (see Patent Document 2) having a reduced friction coefficient and improved wear resistance, and a fixed scroll or orbiting scroll (movable scroll) as a sliding part is used as an aluminum base, and Ni— Examples thereof include a rotary fluid machine (see Patent Document 3) in which a P plating layer and a DLC (diamond-like carbon) thin film are sequentially formed.

JP 2008-261261 A JP 2001-115959 A JP 2006-200455 A

  The technology according to Patent Document 1 described above forms an oxide film layer, an oxide layer, an intermediate layer, and a hard carbon film layer in this order on the surface of a sliding member formed of sintered iron, and has low wear resistance and low on the outer surface. A hard carbon film layer such as DLC, which has excellent friction properties, is in close contact, and has excellent wear resistance and low friction properties during operation, but the base material of the sliding member itself is made of sintered iron. Since the eccentric mass is large as before and the new torque is applied, the torque load of the motor becomes very large when trying to perform ultra-high speed operation. There is a difficulty that it is difficult to reduce the weight.

  Moreover, the technique which concerns on patent document 2 is the resin material and DLC which made the turning scroll the aluminum base material about the sliding member which is a structural member of a compressor, and made the surface contain carbon fiber and a solid lubricant, DLC. It is formed in order and DLC is in close contact, and the eccentric mass is smaller than in the case of the cited document 1, and the torque load of the motor can be suppressed to some extent, so that ultra-high speed operation and weight reduction can be achieved. However, since the Oldham ring, which requires mechanical strength and wear resistance, is made of an iron-based material here, it is difficult to achieve ultra-high speed operation and light weight on the basic structure.

  Further, the technique according to Patent Document 3 is similar to the technique according to Patent Document 2, in which a turning scroll (movable scroll) is used as an aluminum base, and a Ni-P plating layer and a DLC thin film are sequentially formed on the surface thereof. For this reason, it is difficult to achieve ultra-high speed rotation and light weight on the basic structure.

  In addition, the technologies according to Patent Document 2 and Patent Document 3 are those in which DLC is adhered to the surface of a resin material or Ni-P plating layer formed on the surface of an aluminum base material. In general, DLC is a metal material. It is well known that it is difficult to adhere to the surface of the film, and it is necessary to devise an underlayer in order to ensure adhesion. If the base layer is only a resin material or Ni-P plating layer, it will be exposed to high-pressure gas from a new refrigerant, and under the usage conditions where considerable heat generation due to sliding is assumed, adhesion cannot be maintained stably over a long period of time. There is a risk. In particular, the aluminum base material is sufficiently softer than iron, and the surface DLC is hard. Therefore, assuming that the hard DLC is slid under high pressure conditions, the DLC has a base layer or aluminum base material. There is a risk that the DLC may be deformed or the DLC may be peeled off depending on the degree.

  In addition, the reason why the Oldham ring is made of an iron-based material in the technique according to Patent Document 2 is that the sliding member of the compressor rotates eccentrically in the case of an orbiting scroll when it is desired to reduce the eccentric mass during ultra-high speed operation. The eccentric mass can be canceled by providing a structurally balanced mass, but the Oldham ring reciprocates to constrain the rotating motion of the orbiting scroll and cause the orbiting motion to occur. This is thought to be due to the fact that the eccentric mass cannot be canceled because the mass cannot be balanced.

  However, from the viewpoint of reducing the inertial mass of the rotating system in order to reduce the torque load of the motor, it is advantageous to reduce the weight of the Oldham ring, and it can contribute to reducing the size and weight of the entire compressor. More preferable.

  The present invention has been made to solve such problems, and its technical problem is that it contributes to downsizing and weight reduction of the entire compressor, is excellent in durability and reliability, and is applied with a new refrigerant. It is another object of the present invention to provide a scroll compressor that can be operated at ultra high speed.

  In order to solve the above technical problem, the present invention provides a rotating main shaft in which the spiral body of the orbiting scroll and the spiral body of the fixed scroll are meshed with each other in a hermetically sealed case, and the rotating part of the motor is attached to the substantially central part. The orbiting scroll is attached to one end of the crankshaft with a frame interposed therebetween, and the Oldham ring arranged between the orbiting scroll and the frame constrains the rotation of the orbiting scroll when the crankshaft rotates. In a scroll compressor having a structure for making a swivel motion, the Oldham ring is made of an aluminum alloy as a base material, and a bond layer for enhancing adhesion on the surface of the aluminum alloy base material, the hardness of the aluminum alloy base material A buffer layer to compensate for this, and a hard DLC layer. The features. In this scroll compressor, it is preferable that the aluminum alloy is covered with an oxide film.

  Further, in one embodiment of the scroll compressor, between the buffer layer and the DLC layer, the metal content decreases outward from the aluminum alloy base material, and the carbon content is reduced to the aluminum alloy base. A gradient layer made of a mixture of carbon and metal or metal carbide increasing from the material toward the outside is interposed.

  Furthermore, in another embodiment of the scroll compressor, between the buffer layer and the DLC layer, the content of the first metal decreases outward from the aluminum alloy substrate, and the carbon and the first An inclined layer made of a mixture of metals or metal carbide, in which the content of the second metal different from the metal of the metal increases from the aluminum alloy substrate toward the outside, is interposed.

  In addition, another embodiment of the scroll compressor is characterized in that the DLC layer contains 0.5 to 4.5 at% of aluminum. Here, the aluminum is preferably in one state selected from a metal, a boride, a carbide, a nitride, an oxide, and a hydroxide.

In another embodiment of the scroll compressor, the DLC layer is composed of a mixture of SP ² bonded carbon and SP ³ bonded carbon.

  As another embodiment of the scroll compressor, the orbiting scroll is preferably made of the same material structure as that of the Oldham ring.

  According to the scroll compressor of the present invention, the base material of the Oldham ring is made of an aluminum alloy, and a hard DLC layer is formed by interposing an underlayer for supplementing the surface with good adhesion and hardness. The weight of the rotating system can be reduced by about 1/3 of that of conventional iron-based materials, and the anti-adhesive wear between sliding members can be prevented to improve wear resistance and reduce the friction coefficient. The inertial mass can be reduced. In addition, with respect to the orbiting scroll, the eccentric mass of the rotating system is sufficiently reduced as a similar material structure. Furthermore, a hard DLC layer including a base layer on the surface thereof can be formed at a low temperature that does not cause a decrease in strength of the aluminum alloy substrate. As a result, the torque load of the motor can be reduced as much as possible, which contributes to the overall downsizing and weight reduction and is excellent in durability and reliability. Compression performance equivalent to that of using Freon at low cost can be obtained.

It is the side view which showed schematic structure of the scroll compressor which concerns on Example 1 of this invention in the cross section along the extension direction of a rotating main shaft. It is the perspective view which showed the external appearance of the Oldham ring with which the scroll compressor shown in FIG. 1 is equipped. FIG. 2 is a partial cross-sectional view showing an example of a multilayer structure for materials of an Oldham ring and a turning scroll provided in the scroll compressor shown in FIG. 1. FIG. 5 is a local cross-sectional view showing another example of a multilayer structure of materials of an Oldham ring and a turning scroll provided in the scroll compressor shown in FIG. 1.

  FIG. 1 is a side view showing a schematic configuration of the scroll compressor according to the first embodiment of the present invention in a cross-section along the extending direction of the rotation main shaft.

  This scroll compressor is a well-known conventional one in terms of basic structure, and includes a suction port for mounting a suction pipe 113 for sucking in a new refrigerant gas and a discharge port for mounting a discharge pipe 114 for discharging. A fixed scroll 102 having a spiral body is attached to an end side in a sealed case (chamber) 115 provided with a rotor 100a and a rotor 100a of a motor 100 including a rotor (rotating part) 110a and a stator (fixed part) 110b. A rotating scroll 101 having a mating spiral body is attached to one end side in the axial direction of a crankshaft 106, which is a rotating main shaft attached to the part, with a frame 105 interposed therebetween, and a bearing support plate 111 and a secondary bearing 112 are attached to the other end side. The assembly formed by attaching the shaft support member by the spiral scroll of the orbiting scroll 101 and the fixed scroll Embedded in the remaining space portion of the closed casing 115 so that the spiral of the Le 102 and is meshed with each other, and has a then stored sealed by attaching each part structure.

  In this sealed state, the eccentric portion 106a of the crankshaft 106 supported by the main bearing 105a of the frame 105 is inserted into the orbiting bearing attached to the rear surface of the orbiting scroll 101 in detail structure. An Oldham ring 107 disposed between the two parts 105 restrains the rotational movement of the orbiting scroll 101 when the crankshaft 106 rotates, and performs the orbiting movement.

  The pressure (back pressure value) in the back pressure chamber 109 formed by the fixed scroll 102, the orbiting scroll 101, and the frame 105 is controlled by the differential pressure control mechanism 109a. Press it. The pressure inlet side of the differential pressure control mechanism 109 a communicates with the back pressure chamber 109, and the pressure outlet side communicates with a fixed outer peripheral groove provided on the outer periphery of the spiral body of the fixed scroll 102. The fixed outer peripheral groove communicates with the refrigerant gas suction port, whereby the fixed outer peripheral groove always has a suction pressure.

  The suction pipe 113 is for taking in the refrigerant gas, and communicates with the fixed scroll 102. The discharge pipe 114 is for discharging compressed refrigerant gas to the outside. A secondary bearing 112 attached to a bearing support plate 111 at the bottom of the motor 110 supports the crankshaft 106 together with the main bearing 105 a of the frame 105. Incidentally, the chamber on the other end side in the axial direction of the crankshaft 106 in the sealed case 115 is used as an oil reservoir chamber 116 for storing oil.

  The compression operation of the scroll compressor having such a structure will be described. When the motor 110 is driven to rotate the rotor 100a and the crankshaft 106, the orbiting scroll 101 starts the orbiting motion. By this operation, the spiral bodies of the orbiting scroll 101 and the fixed scroll 102 mesh with each other to form a first compression chamber and a second compression chamber.

  At this time, the refrigerant gas flowing in from the suction pipe 113 is compressed in the first compression chamber and the second compression chamber. In the first compression chamber and the second compression chamber, as the crankshaft 106 rotates, the compression operation is performed while the volume is decreased in the central direction, whereby a high-pressure refrigerant gas is formed in the fixed scroll 102. The discharge port 108 is discharged into the discharge chambers 103 and 104 in the sealed case 115 and finally discharged to the outside through the discharge pipe 114.

  The pressure in the back pressure chamber 109 is controlled by a gas contained in oil that lubricates the main bearing 105a and the like of the frame 105, and is controlled by the differential pressure control mechanism 109a so as to have a constant pressure difference with respect to the suction pressure. This pressure is an intermediate pressure between the suction pressure and the discharge pressure, and presses the orbiting scroll 101 against the fixed scroll 102. By pressing at this time, the end plate of the orbiting scroll 101 is brought into close contact with the fixed scroll 102, and the end plate of the orbiting scroll 101 is sealed (sealed) with the intermediate pressure in the back pressure chamber 109.

New refrigerants such as CO ₂ and HFC152a with low global warming potential (GWP) used in the scroll compressor of Example 1 have a lower heat exchange rate than that of conventional chlorofluorocarbons, and are equivalent to the case of using chlorofluorocarbons. In order to obtain a good compression function, it is necessary to increase the capacity or to operate at an ultra high speed without changing the capacity. As described above, in order to increase the capacity, it is necessary to increase the size of the entire compressor. However, since such a method is contrary to the current demand for reduction in size and weight, it cannot be practically adopted.

  Therefore, considering the conditions for ultra-high speed operation without changing the capacity, the eccentric mass is reduced by devising the material of the orbiting scroll 101 of the sliding member and reducing the weight as in Patent Document 2 and Patent Document 3. In addition, it is desirable to reduce the torque load of the motor 100 as much as possible by reducing the inertial mass of the rotating system.

  However, as in Patent Document 2 and Patent Document 3, the base of the orbiting scroll 101 is made of an aluminum-based material, and the base layer for forming a hard DLC layer on the surface thereof is made of a resin material or a Ni-P plating layer. However, there is a risk that the adhesion cannot be stably maintained over a long period of time, and there is a risk that the DLC is peeled off. That is, when measures are taken by the methods of Patent Document 2 and Patent Document 3, it is difficult to achieve ultra-high speed operation and light weight on the basic structure, and there is also a problem with durability to the sliding member on which the DLC layer is formed. There is.

  Therefore, in the scroll compressor according to the first embodiment, attention is paid to improving the material of the Oldham ring 107 disposed between the orbiting scroll 101 and the frame 105.

  FIG. 2 is a perspective view showing an appearance of the Oldham ring 107 provided in the scroll compressor described above.

  The Oldham ring 107 has a substantially annular shape as usual in appearance. On the outer peripheral edge of the surface on the side of the orbiting scroll 101, convex orbiting side keys 107a for restricting the rotational movement of the orbiting scroll 101 are provided at two locations in the radial direction passing through the center. Also, on the outer peripheral edge of the surface on the frame 105 side, convex frame-side keys 107b are provided at two radial positions passing through the center orthogonal to the turning-side key 107a.

  Here, the Oldham ring 107 uses an aluminum alloy as a base material, a bond layer (conductive layer) for enhancing adhesion on the surface of the aluminum alloy base material, and a buffer for supplementing the hardness of the aluminum alloy base material. A layer and a hard DLC layer are sequentially formed. The orbiting scroll 101 has the same material structure. In any case, the aluminum alloy here may be covered with an oxide film.

  Among these, the bond layer (conductive layer) can be exemplified by the case of containing one kind of chromium (Cr) or titanium (Ti) metal.

  The case where the buffer layer contains one kind of chromium nitride (CrN), chromium carbide (CrC), titanium nitride (TiN), and titanium carbide (TiC) can be exemplified.

  By the way, between the buffer layer and the DLC layer, the metal is one of aluminum (Al), chromium (Cr), and titanium (Ti), and the content of the metal is outside the aluminum alloy substrate. An inclined layer made of a mixture of carbon and metal or a metal carbide may be interposed in which the carbon content decreases toward the outside and the carbon content increases outward from the aluminum alloy substrate. Alternatively, between the buffer layer and the DLC layer, the first metal and the second metal are one of aluminum (Al), chromium (Cr), and titanium (Ti), and contain the first metal. From a mixture of metals or metal carbide in which the amount decreases from the aluminum alloy substrate outward and the content of carbon and a second metal different from the first metal increases outward from the aluminum alloy substrate An inclined layer may be interposed.

Further, the DLC layer may contain 0.5 to 4.5 at% of aluminum. However, here, the aluminum is preferably in one state selected from metal, boride, carbide, nitride, oxide, and hydroxide. Furthermore, the DLC layer may be a mixture of SP ² bonded carbon and SP ³ bonded carbon.

When the Oldham ring 107 and the orbiting scroll 101 which are such sliding members are produced by forming the above-described material structure in a multilayered manner on the surface of the aluminum alloy base material, a sputtering method or an ion is applied to the surface of the aluminum alloy base material. First step of forming a bond layer (conductive layer) by a plating method, and improving the adhesion on the bond layer (conductive layer) in a state where a bias voltage is applied to the aluminum alloy substrate, and supplementing the hardness The buffer layer is formed (an inclined layer is further formed on the buffer layer as necessary), and a DLC layer (aluminum is added if necessary) on the buffer layer (or the inclined layer) or SP ^{2 is used.} And the second step of forming (bonded carbon and SP ³ bonded carbon are mixed).

  In any case, in order to reduce the eccentric mass of the rotating system, the Oldham ring 107 and the orbiting scroll 101, which are sliding members, are simply made of an aluminum alloy base material, the aluminum alloy is generally soft and inferior in slidability, Considering the fact that the sliding speed is large and the heat generation amount is large, the wear resistance that can withstand ultra-high speed operation cannot be obtained. Further, if the Oldham ring 107 and the orbiting scroll 107 are made of the same metal material (aluminum alloy materials), the orbiting scroll 101 and the orbiting side key 107a of the Oldham ring 107 are liable to cause adhesive wear, which is inconvenient.

  Therefore, the Oldham ring 107 and the orbiting scroll 101 are not only made of an aluminum alloy base material, but also by forming a hard DLC layer on the surface with the above-described material structure, thereby preventing adhesive wear and generating heat by sliding. Can also be reduced. By the way, aluminum alloys have a small elastic coefficient and a large linear expansion coefficient, so that it is easy to peel off simply by coating a hard DLC layer. It is important in securing the properties and hardness and preventing peeling. Further, it can be said that, when forming the underlayer, a CVD process or the like having a high process temperature is difficult to apply because the strength is reduced.

  FIG. 3 is a local cross-sectional view showing an example of a multilayer structure of the materials of the Oldham ring 107 and the orbiting scroll 101 here.

  Referring to FIG. 3, the multilayer structure here is formed on the surface of the Oldham ring 107 and the orbiting scroll 101 made of an aluminum alloy substrate whose surface is covered with an oxide film (that is, on the oxide film of the aluminum alloy substrate). , A bond layer (conductive layer), a buffer layer, a gradient layer, and a DLC layer are formed in this order.

  FIG. 4 is a local sectional view showing another example of the multilayer structure of the Oldham ring 107 and the orbiting scroll 101.

  Referring to FIG. 4, the multilayer structure here has a bond layer (conductive layer), a buffer layer, a surface of the Oldham ring 107 and the orbiting scroll 101 made of an aluminum alloy substrate whose surface is not covered with an oxide film, An inclined layer and a DLC layer are sequentially formed.

  In the scroll compressor provided with the Oldham ring 107 and the orbiting scroll 101 of these multilayer structure and material structure, the base material of the Oldham ring 107 is basically made of an aluminum alloy, and the surface thereof has good adhesion to supplement the hardness. Since a hard DLC layer is formed with an underlayer interposed, it is possible to reduce the weight by about 1/3 compared to the case of conventional iron-based materials and to prevent wear and abrasion between sliding members. The improvement of the property and the reduction of the friction coefficient can be achieved, and the inertial mass of the rotating system can be reduced. Further, the turning mass of the rotating system can be reduced by adopting the same multilayer structure and material structure for the orbiting scroll 101 as well. Furthermore, a hard DLC layer including a base layer on the surface thereof can be formed at a low temperature that does not cause a decrease in strength of the aluminum alloy substrate. As a result, since the torque load of the motor 100 can be reduced as much as possible, it can contribute to downsizing and weight reduction of the entire compressor, and is excellent in durability and reliability, and is operated at a high speed by applying a new refrigerant ( The drive signal to the motor 100 can have a frequency of about 200 Hz), and the compression performance equivalent to the case of using Freon can be obtained at low cost.

DESCRIPTION OF SYMBOLS 101 Orbiting scroll 102 Fixed scroll 103,104 Discharge chamber 105 Frame 105a Main bearing 106 Crankshaft 106a Eccentric part 107 Oldham ring 107a Orbit side key 107b Frame side key 108 Discharge port 109 Back pressure chamber 109a Differential pressure control mechanism 110 Motor 110a Rotor 110b Stator 111 Bearing support plate 112 Sub bearing 113 Suction pipe 114 Discharge pipe 115 Sealed case (chamber)
116 Oil storage room

Claims (14)

The spiral body of the orbiting scroll and the spiral body of the fixed scroll are meshed with each other in the hermetic case, and the frame is interposed on one end side of the crankshaft that becomes the rotating main shaft with the rotating part of the motor attached to the substantially central part. In the scroll compressor having a structure in which the orbiting scroll is attached and the Oldham ring arranged between the orbiting scroll and the frame constrains the rotation motion of the orbiting scroll when the crankshaft rotates, and performs the orbiting motion.
The Oldham ring includes an aluminum alloy as a base material, a bond layer for enhancing adhesion on the surface of the aluminum alloy base material, a buffer layer for supplementing the hardness of the aluminum alloy base material, and hard diamond A scroll compressor, wherein a like carbon layer is formed in order.   The scroll compressor according to claim 1, wherein the aluminum alloy is covered with an oxide film.   2. The scroll compressor according to claim 1, wherein the metal content decreases outward from the aluminum alloy base material and the carbon content is between the buffer layer and the diamond-like carbon layer. A scroll compressor comprising an inclined layer made of a mixture of carbon and metal or metal carbide increasing outward from the aluminum alloy substrate.   2. The scroll compressor according to claim 1, wherein a content of the first metal decreases from the aluminum alloy substrate to the outside between the buffer layer and the diamond-like carbon layer, and carbon and Scroll compression characterized by comprising an inclined layer made of a mixture of metals or metal carbides in which the content of a second metal different from the first metal increases from the aluminum alloy substrate toward the outside Machine.   The scroll compressor according to claim 1, wherein the diamond-like carbon layer contains 0.5 to 4.5 at% of aluminum.   6. The scroll compressor according to claim 5, wherein the aluminum is in a state selected from a metal, a boride, a carbide, a nitride, an oxide, and a hydroxide. . In claim 1 a scroll compressor, wherein said diamond-like carbon layer, a scroll compressor, wherein a and SP ² -bonded carbon and SP ³ -bonded carbon made of a mixture.   The scroll compressor according to claim 1, wherein the orbiting scroll has the aluminum alloy as a base material, and the bond layer, the buffer layer, and the diamond-like carbon layer are formed on a surface of the aluminum alloy base material. A scroll compressor characterized by being formed in order.   9. The scroll compressor according to claim 8, wherein the aluminum alloy is covered with an oxide film.   9. The scroll compressor according to claim 8, wherein the metal content decreases outwardly from the aluminum alloy substrate and the carbon content is between the buffer layer and the diamond-like carbon layer. A scroll compressor comprising an inclined layer made of a mixture of carbon and metal or metal carbide increasing outward from the aluminum alloy substrate.   9. The scroll compressor according to claim 8, wherein the content of the first metal decreases from the aluminum alloy base material to the outside between the buffer layer and the diamond-like carbon layer, and carbon and Scroll compression characterized by comprising an inclined layer made of a mixture of metals or metal carbides in which the content of a second metal different from the first metal increases from the aluminum alloy substrate toward the outside Machine.   The scroll compressor according to claim 8, wherein the diamond-like carbon layer contains 0.5 to 4.5 at% of aluminum.   13. The scroll compressor according to claim 12, wherein the aluminum is in a state selected from a metal, a boride, a carbide, a nitride, an oxide, and a hydroxide. . In claim 8 scroll compressor, wherein said diamond-like carbon layer, a scroll compressor, wherein a and SP ² -bonded carbon and SP ³ -bonded carbon made of a mixture.

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