JP2004076685A - Scroll type fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll type fluid machine capable of enhancing vacuum performance by reducing the quantity of a gas discharged from an anodic oxide coating film to a fluid chamber. <P>SOLUTION: This scroll type fluid machine 1 has a fixed scroll 20 and a rotating scroll 30 which are made of aluminum alloy cast materials. The rotating scroll 30 is constituted to eccentrically rotate in relation to the fixed scroll 20, so that a sealed fluid chamber 20a is constituted by the fixed scroll 20 and the rotating scroll 30. The surfaces of the fixed scroll 20 and the rotating scroll 30 have an anodic oxide coating film 32C having minute pores 32a, and an impregnation 32D of a metal and a resin is impregnated in the pores 32a. A layer 32E consisting of lubricating oil or grease is provided on the anodic oxide coating film 32C in a thickness of 0.01-1μm. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a scroll-type fluid machine, and more particularly to a scroll type fluid machine that includes a fixed scroll and an orbiting scroll, and the volume of a fluid chamber defined in the fixed scroll and the orbiting scroll changes by the eccentric rotation of the orbiting scroll with respect to the fixed scroll. Thus, the present invention relates to a scroll type fluid machine for creating a vacuum or high pressure state.
[0002]
[Prior art]
As a device for creating a vacuum state or a high-pressure state, a scroll-type fluid machine including a fixed scroll and an orbiting scroll arranged to mesh with each other is known. The scroll-type fluid machine is provided with a suction adapter and an exhaust adapter.When a desired container is to be evacuated, the container is connected to the suction adapter, and when the desired container is to be set to a high pressure. Is connected to the exhaust adapter. The scroll type fluid machine is sometimes referred to as a scroll type vacuum pump because it is sometimes used in a vacuum application. This type of fluid machine is used in the fields of physicochemical analyzers, electron microscopes, semiconductor manufacturing equipment, and the like.
[0003]
Specifically, the fixed scroll of the scroll type fluid machine is provided immovably with respect to a machine main body constituting an outer frame or the like of the scroll type fluid machine, and has a spiral fixed scroll plate. Further, the orbiting scroll has a spiral orbiting scroll plate which is opposed along substantially the entire surface of the fixed scroll plate, and the orbiting scroll plate is supported by the machine body so as to rotate eccentrically with respect to the fixed scroll plate. I have. A part of the fixed scroll and a part of the orbiting scroll abut each other, and by this abutment, a fluid chamber sealed in the fixed scroll and the orbiting scroll is defined. The portions that come into contact with each other form sliding surfaces that slide with each other when the orbiting scroll is eccentrically rotating and also define surfaces that define a fluid chamber. By the eccentric rotation of the orbiting scroll, the fluid flows into the fluid chamber in which the sealed state is temporarily released via the suction adapter, and the fluid chamber is again in the sealed state, and the volume in the fluid chamber is reduced and the fluid chamber is reduced. Is compressed, and the fluid is discharged to the outside of the fluid machine via the exhaust adapter.
[0004]
The fixed scroll and the orbiting scroll are made of an aluminum alloy casting in order to increase the rotation speed of the orbiting scroll and reduce the weight of the fluid machine. The sliding surfaces of the fixed scroll and the orbiting scroll that define the fluid chamber are provided with an alumite coating by performing an alumite treatment to increase the hardness of the sliding surfaces. In this alumite film, a number of fine porous layers are formed.
[0005]
When the orbiting scroll is eccentrically rotating, the alumite films provided on the respective sliding surfaces of the orbiting scroll and the fixed scroll slide against each other. At this time, problems such as seizure, galling, and abrasion occur. Tends to occur. In order to improve these problems, a processing method is generally used in which a porous metal of the alumite film is impregnated with a metal or a resin to enhance the lubricity of the alumite film and improve the wear resistance.
[0006]
[Problems to be solved by the invention]
In the conventional fixed scroll, orbiting scroll, as described above, the sliding surface is hardened by alumite treatment, and the alumite film is impregnated with a metal or resin to enhance lubricity and improve wear resistance. There is no problem in terms of durability.
[0007]
However, since the alumite film is porous as described above, the surface area is large. Gas is present in the alumite film and aluminum alloy, but the large surface area of the alumite film increases the gas release area from the alumite film into the fluid chamber, resulting in a large amount of gas released. turn into. The amount of gas released is one of the performance factors of scroll-type fluid machines, and a large amount of this means that the performance of scroll-type fluid machines is low, such as aluminum alloy or stainless steel that has not been subjected to alumite treatment. The performance was greatly inferior to the scroll type fluid machine having the fixed scroll and the orbiting scroll made of the above materials. For this reason, it was thought that the alumite treatment was not suitable for fixed scrolls and orbiting scrolls that required vacuum performance.
[0008]
Therefore, an object of the present invention is to provide a scroll-type fluid machine that improves vacuum performance by reducing the amount of gas released from the alumite film into the fluid chamber.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a machine main body, a fixed scroll having a spiral fixed scroll plate provided immovably with respect to the machine main body, and substantially along the entire surface of the fixed scroll plate. An orbiting scroll plate opposed to the fixed scroll plate, the orbiting scroll plate being supported by the machine body so as to rotate eccentrically with respect to the fixed scroll plate. A sealed fluid chamber is defined between the fixed scroll plate and the orbiting scroll plate. The fixed scroll and the orbiting scroll are made of an aluminum alloy casting, and the fixed scroll and the orbiting scroll define the fluid chamber. The surface of the orbiting scroll is provided with an alumite film on which fine pores have been formed by alumite treatment. Alternatively, the present invention provides a scroll-type fluid machine in which the metal and the resin are impregnated, in which a layer of lubricating oil or grease having a thickness of 0.01 to 1 μm is provided on the alumite film. .
[0010]
Here, the lubricating oil is preferably of a paraffin type, a silicon type, a fluorine type, or a phenyl ether type.
[0011]
The grease is preferably a silicon-based, fluorine-based, or phenyl ether-based grease.
[0012]
The aluminum alloy casting preferably contains 4.0 to 10% of Si and 4.0% or less of Cu.
[0013]
Preferably, the metal comprises silver or gold or molybdenum disulfide.
[0014]
The resin is preferably an ethylene tetrafluoride resin.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
A scroll type fluid machine 1 according to an embodiment of the present invention will be described with reference to FIGS. The scroll-type fluid machine 1 has a machine body 10 constituting an outer frame, and the machine body 10 is provided with a suction adapter 11 and an exhaust adapter 12 respectively. The suction adapter 11 and the exhaust adapter 12 are formed with through holes 11a and 12a, respectively, and communicate with a fixed scroll case 21 described later. When it is desired to evacuate the inside of a desired container (not shown), the container is connected to the suction adapter 11 and the scroll type fluid machine 1 is operated so that the inside of the container can be evacuated. It is configured. During the operation of the scroll-type fluid machine 1, air serving as a fluid in the container is extracted through the scroll-type fluid machine 1 and discharged from the exhaust adapter 12. Conversely, when it is desired to set the inside of a desired container to a high-pressure state, the container is connected to the exhaust adapter 12 and the scroll-type fluid machine 1 is operated so that the inside of the container can be set to a high-pressure state. It is configured. A fixed scroll 20 and an orbiting scroll 30 are provided inside the machine body 10. A motor case 40 having a motor (not shown) is connected to the outside of the machine body 10.
[0016]
The fixed scroll 20 has a fixed scroll case 21. The fixed scroll case 21 is composed of two substantially identical circular end surfaces 21A and 21B and a peripheral surface 21C connecting these end surfaces. The end surfaces 21A and 21B are in a parallel positional relationship, and the fixed scroll case 21 is immovably fixed to the machine body 10.
[0017]
An orbiting scroll disk 31 constituting the orbiting scroll 30 is provided inside the fixed scroll case 21. The orbiting scroll disk 31 has a circular shape slightly smaller in radius than the end faces 21A and 21B, is spaced apart from the end faces 21A and 21B by an equal distance, and is arranged in a positional relationship parallel to the end faces 21A and 21B. One surface 31A of the orbiting scroll disk 31 faces one end surface 21A, and the other surface 31B of the orbiting scroll disk 31 faces the other end surface 21B.
[0018]
A through hole 30a is formed at a position eccentric from the center of the orbiting scroll disk 31, and the crankshaft 50 passes through the through hole 30a. The orbiting scroll disk 31 is supported on the crankshaft 50 via a bearing 51, and is rotatable with respect to the crankshaft 50. The crankshaft 50 is supported by the machine body 10 via a bearing 52, and is rotatable with respect to the machine body 10. Therefore, the orbiting scroll 30 is in a state of being indirectly supported by the machine main body 10. The crankshaft 50 is drivingly connected to a motor (not shown) in the motor case 40, and is configured such that when the motor is driven, the crankshaft 50 rotates. In a portion of the crankshaft 50 located in the through hole 30a, the rotation axis of the crankshaft 50 is not located at the center of the portion in the radial direction but at an eccentric position. Further, as described above, the through hole 30a is formed at a position eccentric from the center of the orbiting scroll disk 31. For this reason, the orbiting scroll disk 31 is configured to rotate eccentrically with respect to the fixed scroll case 21 when the crankshaft 50 rotates.
[0019]
On the orbiting scroll disk 31, a plate-shaped orbiting scroll plate 32 is provided. More specifically, one orbiting scroll plate 32A is provided on one surface 31A of orbiting scroll disk 31, and the other orbiting scroll plate 32B is provided on the other surface 31B of orbiting scroll disk 31. Has been. As shown in FIG. 2, the orbiting scroll plates 32A and 32B have a shape in which a band-shaped plate is spirally rounded, and one side edge of each is fixed to one surface 31A and the other surface 31B, respectively. It is in a state of being left. When viewed in the cross-sectional view shown in FIG. 1, the orbiting scroll plate 32A has a fin shape protruding from one surface 31A of the orbiting scroll disk 31 to one end surface 21A of the fixed scroll case 21. Similarly, the orbiting scroll plate 32B has a fin shape protruding from the other surface 31B of the orbiting scroll disk 31 to the other end surface 21B of the fixed scroll case 21. The orbiting scroll plate 32 constitutes the orbiting scroll 30 together with the orbiting scroll disk 31.
[0020]
A fixed scroll plate 22 having a plate shape is provided on the inner peripheral surface of the fixed scroll case 21 at the end surfaces 21A and 21B. More specifically, the fixed scroll plate 22A is provided on the end surface 21A, and the fixed scroll plate 22B is provided on the end surface 21B. As shown in FIG. 2, the fixed scroll plates 22A and 22B have a shape in which a band-shaped plate is spirally rounded similarly to the orbiting scroll plates 32A and 32B, and one side edge of each of the end surfaces 21A and 21B. It is in a state of being stuck to. When viewed in the cross-sectional view shown in FIG. 1, the fixed scroll plate 22A has a fin shape protruding from one end face 21A of the fixed scroll case 21 to one face 31A of the orbiting scroll disk 31. Similarly, the fixed scroll plate 22B has a fin shape protruding from the other end surface 21B of the fixed scroll case 21 to the other surface 31B of the orbiting scroll disk 31. As shown in FIG. 2, the fixed scroll plate 22 and the orbiting scroll plate 32 are engaged with each other, and the entire surface of the fixed scroll plate 22 is opposed along substantially the entire surface of the orbiting scroll plate 32. It is in a state of being arranged. The fixed scroll plate 22 forms the fixed scroll 20 together with the fixed scroll case 21.
[0021]
The surface of the fixed scroll plate 22 and the surface of the orbiting scroll plate 32 are configured to be able to contact at two or more places at the same time. One surface 31A and the other surface 31B of the orbiting scroll disk 31 are mirror surfaces, respectively, and are always in contact with the tips of the fixed scroll plates 22A and 22B in the protruding direction. Similarly, the inner peripheral surface of the fixed scroll case 21 and the end surfaces 21A and 21B are mirror surfaces, and are always in contact with the leading ends of the orbiting scroll plates 32A and 32B in the protruding direction. More specifically, as shown in FIG. 3, a tip seal 33 made of a self-lubricating resin is provided along the tip of a spiral orbiting scroll plate 32A facing one end face 21A. Similarly, a tip seal 23 made of self-lubricating resin is provided along the tip of the spiral fixed scroll plate 22A facing the orbiting scroll disk 31A. The orbiting scroll plate 32 is in contact with the fixed scroll case 21 via the tip seals 23 and 33, and the fixed scroll plate 22 is in contact with the orbiting scroll disk 31. The tip seals 23 and 33 enhance the sealing performance between one end surface 21A of the fixed scroll case 21 and the orbiting scroll plate 32A, and seal the one surface 31A of the orbiting scroll disk 31 and the fixed scroll plate 22A. Sex has been enhanced. For convenience of explanation, FIG. 3 shows one fixed scroll plate 22A, the orbiting scroll plate 32A and the like, but the same applies to the other fixed scroll plate 22B and the orbiting scroll plate 32B.
[0022]
The contact between the fixed scroll 20 and the orbiting scroll 30 causes the orbiting scroll plate 32, the fixed scroll plate 22, the orbiting scroll disk 31, and the fixed scroll case 21 between the fixed scroll 20 and the orbiting scroll 30. An enclosed and sealed fluid chamber 20a is defined. The surfaces that define the fluid chambers 20a form sliding surfaces that slide with each other when the orbiting scroll 30 is eccentrically rotating. When the orbiting scroll plate 32 rotates eccentrically, the fixed scroll plate 22 and the orbiting scroll plate 32 slide with each other, and the contact position between the fixed scroll plate 22 and the orbiting scroll plate 32 changes. The volume of the fluid chamber 20a is reduced by the change of the contact position.
[0023]
The fixed scroll 20 and the orbiting scroll 30 are castings made of an aluminum alloy. This aluminum alloy casting contains 4.0 to 10% of Si and contains Cu in an amount of 4.0% or less. The reason why the content of Si is set to 4.0% to 10% and the content of Cu is set to 4.0% or less is to reduce the amount of alloying elements, particularly, Si and Cu which form a eutectic during casting and form a network. Thereby, when performing the alumite treatment described below, it is possible to reduce the unevenness of the surface caused by the eutectic material falling off, and it is possible to suppress the variation in the thickness of the alumite film 32C described below. .
[0024]
The surfaces of the fixed scroll 20 and the orbiting scroll 30 that define the fluid chamber 20a, that is, the fixed scroll plate 22, one surface 31A and the other surface 31B of the orbiting scroll disk 31, one end surface 21A and the other of the fixed scroll case 21. The end surface 21B and the surface of the orbiting scroll disk 31 are subjected to an alumite treatment, and as shown in FIG. 4, an alumite film 32C is provided by the alumite treatment. For convenience of explanation, FIG. 4 shows only the surface of the orbiting scroll plate 32, but one end surface 21A and the other end surface 21B of the fixed scroll case 21, the fixed scroll plate 22, and the orbiting scroll disk 31 The same applies to the respective surfaces of the one surface 31A and the other surface 31B. By providing the alumite coating 32C, the surfaces of the fixed scroll 20 and the orbiting scroll 30 that define the fluid chamber 20a are hardened.
[0025]
The alumite film 32C has countless fine pores 32a formed therein. As shown in FIG. 4, an impregnated material 32D made of a metal and a resin is impregnated in the porous 32a. The impregnated material 32D is formed by impregnating a resin after impregnating a metal. As the metal to be impregnated, gold, silver, molybdenum disulfide or the like is used, and as the resin, ethylene tetrafluoride or the like is used. By impregnating the porous 32a with the metal, the porous 32a can be closed. Silver, gold, molybdenum disulfide and the like were used as the metals because these metals have a low coefficient of friction. Since the coefficient of friction is low, the sliding characteristics between the orbiting scroll plate 32 and the fixed scroll plate 22 that are in contact with each other can be improved, and the durability can be improved. In addition, these metals are suitable for closing the porous layer 32a, and can reduce the release of gas from the alumite film 32C. Furthermore, when a tetrafluoroethylene resin is added to the metal, the wear resistance can be further increased, and gas emission can be effectively reduced.
[0026]
As shown in FIG. 4, a layer 32E made of lubricating oil having a thickness of 0.01 to 1 μm is provided on the alumite coating 32C in a state where the metal or the like is impregnated in the porous 32a. As the lubricating oil, paraffinic, silicone, fluorine, and phenyl ether oils are used. Since the layer 32E made of lubricating oil is provided, a film of lubricating oil is generated on the outermost surface of the alumite film 32C, which is a porous layer, and the surface area of the alumite film 32C can be reduced. For this reason, the amount of released gas can be more effectively reduced in addition to the above-described effects of the metal and the like. Further, the sealing performance by the tip seals 22 and 33 can be improved, and the vacuum performance can be further improved. The lubricating oil was used as the material of the layer 32E because a thin film was easily formed on the alumite film 32C. The lubricating oils of paraffinic type or the like are used because the vapor pressure of these lubricating oils is low and lower than the minimum pressure in the vacuum system constituted by the fixed scroll 20 and the orbiting scroll 30, so that the oil component is This is because it is difficult to generate steam at the time, and contamination in the vacuum system can be prevented. The reason why the thickness of the lubricating oil film is set to 1 μm or less is that if it is thicker, contamination in the vacuum system becomes a problem. The reason why the thickness of the lubricating oil film is set to 0.01 μm or more is that if the thickness is smaller than this, it is difficult to obtain the effect of improving the vacuum performance.
[0027]
When a container (not shown) is connected to the suction adapter 11 of the scroll type fluid machine 1 having the above configuration and a motor (not shown) is driven, the contact position between the fixed scroll plate 22 and the orbiting scroll plate 32 is changed to the orbiting scroll. The volume changes due to the eccentric rotation of the plate 32, and the volume of the fluid chamber 20a decreases. As the volume decreases, the position of the fluid chamber 20 a moves in the circumferential direction of the spiral orbiting scroll plate 32 and the fixed scroll plate 22, and the outer periphery of the spiral formed by the fixed scroll plate 22 and the orbiting scroll position 32. From the position to the inside of the spiral. More specifically, when the orbiting scroll plate 32 is eccentrically rotating, the contact between the fixed scroll plate 22 and the orbiting scroll plate 32 is temporarily released in the fluid chamber 20a at the outermost peripheral position of the spiral, It communicates with the through hole of the suction adapter 11. At this time, air as a fluid in a container (not shown) communicating with the through hole flows into the fluid chamber 20a. Then, the fixed scroll plate 22 and the orbiting scroll plate 32 immediately come into contact with each other, and the fluid chamber 20a is sealed. Thereafter, the volume of the fluid chamber 20a continues to decrease, and the fluid chamber 20a moves inward of the spiral along the periphery of the spiral and continues to compress the air in the fluid chamber 20a. The center of the spiral communicates with the through hole 12a of the exhaust adapter 12, and when the fluid chamber 20a reaches the center of the spiral, the air in the fluid chamber 20a flows from the through hole 12a of the exhaust adapter 12 to the scroll type fluid machine. 1 to the outside.
[0028]
Next, an experiment was conducted to test the amount of gas released from the material according to the present invention (the present invention) that defines the fluid chamber 20a of the scroll fluid machine 1 according to the present embodiment. The product of the present invention is a fixed scroll 20 and an orbiting scroll 30 of the scroll type fluid machine according to the present embodiment, and alumite treatment is performed on a metal piece of an aluminum alloy containing 7.0% Si and 0.08% Cu. After forming an alumite film on the entire surface of the alumite film, the porous body of the alumite film is impregnated with an ethylene tetrafluoride resin, and then silver is deposited. A layer of oil having a thickness of 0.1 μm was formed. The product of the present invention has a rectangular parallelepiped shape, each of 10 mm in length and width and 1 mm in height.
[0029]
For comparison, a conventional product having a surface defining a fluid chamber of a conventional scroll type fluid machine was used. The conventional product differs from the product of the present invention only in that a 0.1 μm-thick layer made of the same lubricant as the layer 32E is not formed on the entire surface of the alumite film. In the test, the product of the present invention and the conventional product were separately placed in a chamber of an experimental apparatus by thermal desorption gas analysis (TDS), and the temperature was raised at 60 ° C./min, and the pressure change in the chamber was measured. It was done by doing.
[0030]
As shown in FIG. 5, in the experimental results, the gas emission amount of the product of the present invention is smaller than that of the conventional product at any temperature. For example, at about 150 ° C., the pressure in the chamber is about 5 × 10 ^-4 It can be seen that Pa and the degree of vacuum are high, and the gas release amount is low. On the other hand, in the conventional product, 5 × 10 ^-3 It can be seen that Pa and the degree of vacuum are low, and the amount of released gas is large.
[0031]
Next, an experiment on the vacuum performance of the product of the present invention, which is an actual scroll type fluid machine 1 according to the present embodiment, was performed. For comparison, a conventional scroll type fluid machine, which is an actual machine, was used. The conventional product differs from the present invention only in that no lubricating oil layer is provided on the alumite film provided on the surfaces of the fixed scroll and the orbiting scroll that define the fluid chamber. In the experiment, the suction adapter 11 of the scroll-type fluid machine 1 was covered with a lid, a motor (not shown) was driven, and a change in air pressure inside the lid was measured for evaluation. In the test using the actual machine, the vacuum performance based on two factors, namely, the amount of gas released from the alumite film 32C and the aluminum alloy, and the sealing properties of the tip seals 23 and 33 due to the formation of the lubricating oil layer 32E. Comprehensive evaluation can be performed.
[0032]
As shown in FIG. 6, in the experimental results, the product of the present invention has higher vacuum performance than the conventional product at any time. For example, in the product of the present invention, it takes about 18 minutes for the pressure to reach 2 Pa. On the other hand, in the conventional product, it takes about 40 minutes until the atmospheric pressure becomes 2 Pa. From this difference in time, it can be seen that the product of the present invention emits less gas from the alumite film 32C, improves the shielding properties of the tip seals 23 and 33, and significantly improves vacuum performance. Therefore, it can be understood that a desired vacuum state can be quickly achieved.
[0033]
The scroll type fluid machine 1 according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, in the present embodiment, the layer 32E made of lubricating oil is provided on the alumite film 32C in a state in which the metal or the like is impregnated in the porous material. May be provided. As the grease in this case, a silicone grease, a fluorine grease or a phenyl ether grease is preferably used. Grease was used as the material of the layer because a thin film was easily formed on the alumite film. Further, the use of silicon-based grease as the grease, because the vapor pressure of these greases is low, makes it difficult for oil to become steam, and can prevent contamination in the vacuum system constituted by the fixed scroll and the orbiting scroll. .
[0034]
Although the porous material of the alumite film 32C is impregnated with the impregnated material 32D of metal and resin, only the metal such as gold, silver, and molybdenum disulfide may be impregnated.
[0035]
In addition, the impregnated material 32D is impregnated with a resin after being impregnated with a metal. On the contrary, the impregnated material 32D may be impregnated with a metal after being impregnated with a resin.
[0036]
【The invention's effect】
According to the scroll-type fluid machine according to the first aspect, the fixed scroll and the orbiting scroll that define the fluid chamber are provided with the fine anodized film formed with a fine porous by alumite processing. The sliding surface on which the orbiting scroll and the orbiting scroll abut against each other can be hardened, and the durability can be improved. In addition, since the porous material is impregnated with a metal, or a metal and a resin, the lubricating property of the alumite film can be improved, and at the same time, the porous material can be closed, and the amount of gas released from the alumite film can be reduced. can do. Furthermore, since a layer of lubricating oil or grease having a film thickness of 0.01 to 1 μm is provided on the alumite film, the amount of gas released from the alumite film can be reduced to a higher level, and fixed. The sealing performance of the tip seal for sealing between the scroll plate and the orbiting scroll can be improved, and a high-performance machine with improved vacuum performance can be provided.
[0037]
Further, since the layer provided on the alumite film is made of lubricating oil or grease, a thin layer can be easily formed on the alumite film. Further, since the thickness of the lubricating oil or grease layer is set to 1 μm or less, it is possible to prevent contamination in the vacuum system including the fixed scroll and the orbiting scroll. In addition, since the thickness of the lubricating oil or grease layer is set to 0.01 μm or more, good vacuum properties can be obtained.
[0038]
According to the scroll-type fluid machine according to claims 2 and 3, since the lubricating oil is a paraffinic, silicon-based, fluorine-based, or phenyl ether-based, the grease is a silicon-based, fluorine-based, or phenyl ether-based grease. Therefore, the vapor pressure of the lubricating oil and grease can be reduced, and the oil can be less likely to be vaporized in the vacuum system. For this reason, contamination in the vacuum system can be prevented.
[0039]
According to the scroll type fluid machine according to the fourth aspect, since the aluminum alloy casting contains 4.0 to 10% of Si and 4.0% or less of Cu, the alloy element, particularly, the eutectic at the time of casting. Thus, the amount of Si and Cu generated in a network can be reduced, and the surface irregularities caused by the eutectic material falling off during the alumite treatment can be reduced. In addition, variations in the thickness of the alumite film can be suppressed.
[0040]
According to the scroll type fluid machine according to claims 5 and 6, the metal is silver or gold or molybdenum disulfide, and the resin is an ethylene tetrafluoride resin. The coefficient of friction of these materials is low, and the sliding characteristics between the orbiting scroll plate and the fixed scroll plate that are in contact with each other can be improved. For this reason, durability can be improved. Further, these metals and resins are suitable for closing the porous material, and can reduce the release of gas from the alumite film.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a scroll type fluid machine according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along the line II-II in FIG.
FIG. 3 is an essential part cross-sectional view showing a fixed scroll and an orbiting scroll of the scroll fluid machine according to the embodiment of the present invention.
FIG. 4 is an enlarged schematic view showing a surface of a sliding surface of a fixed scroll and an orbiting scroll of the scroll fluid machine according to the embodiment of the present invention.
FIG. 5 is a graph showing the results of an experiment on gas release characteristics of a product of the present invention and a conventional product by thermal desorption spectroscopy (TDS).
FIG. 6 is a graph showing results of an experiment on vacuum characteristics of a scroll type fluid machine according to the present embodiment and a conventional scroll type fluid machine using actual machines.
[Explanation of symbols]
1. Scroll type fluid machine
10 Machine body
20 fixed scroll
20a Fluid chamber
22 Fixed scroll plate
30 orbiting scroll
32 orbiting scroll board
32C anodized film
32D Impregnated with metal and resin
32E layer
32a porous

Claims (6)

Machine body,
A fixed scroll which is provided immovably with respect to the machine body and has a spiral fixed scroll plate;
A spiral scroll plate opposed to the fixed scroll plate along substantially the entire surface of the fixed scroll plate, and the orbiting scroll plate is supported by the machine main body so as to rotate eccentrically with respect to the fixed scroll plate. Prepare,
In the fixed scroll and the orbiting scroll, a sealed fluid chamber is defined between the fixed scroll plate and the orbiting scroll plate,
The fixed scroll and the orbiting scroll are castings made of an aluminum alloy, and the surfaces of the fixed scroll and the orbiting scroll that define the fluid chamber are provided with an alumite film on which fine porous material is formed by anodizing. In the scroll, a porous fluid machine in which the metal is impregnated with the metal, or the metal and the resin,
A scroll type fluid machine characterized in that a layer made of lubricating oil or grease having a thickness of 0.01 to 1 [mu] m is provided on the alumite film. 2. The scroll-type fluid machine according to claim 1, wherein the lubricating oil is a paraffin-based, silicon-based, fluorine-based, or phenyl ether-based lubricant. 2. The scroll-type fluid machine according to claim 1, wherein said grease is a silicon-based, fluorine-based, or phenyl ether-based grease. The scroll type fluid machine according to claim 1, wherein the aluminum alloy casting contains 4.0 to 10% of Si and 4.0% or less of Cu. The scroll-type fluid machine according to claim 1, wherein the metal is made of silver, gold, or molybdenum disulfide. The scroll type fluid machine according to claim 1, wherein the resin is an ethylene tetrafluoride resin.

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