JP2012229629A - Method for manufacturing fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve seizure resistance and wear resistance in a sliding part and to reduce sliding loss in a fluid machine in which efficiency and durability are required.SOLUTION: In the method for manufacturing the fluid machine with an anodic oxide film formed on a surface of a slide member, a step of forming the anodic oxide film includes: a pre-processing step of cleansing a material; an anodizing step where electrolyzation is performed at an electrolytic temperature of 20°C more and with a film thickness of 4 μm or less; and a sealing drying step for performing processing at a sealing drying temperature of 80°C or less. Accordingly, the slide member for which improvement in seizure resistance and wear resistance, and the reduction of sliding loss can be implemented, and the method for manufacturing the fluid machine having high reliability and efficiency can be provided.

Description

  The present invention relates to a sliding member used for a relatively sliding part and a fluid machine for transporting a fluid. In particular, the present invention relates to a method for manufacturing a scroll type fluid machine that is used in refrigeration equipment, air conditioning equipment, and the like, and compresses or expands HFC-based alternative refrigerant gas that is high-pressure refrigerant gas and carbon dioxide gas that is natural refrigerant. .

  Conventionally, compressors for refrigerating and air-conditioning have been widely known as compressors having a reciprocating type, a rolling piston type, and a scroll type. Both methods are used in the field of refrigeration and air conditioning for home use and business use. The typical structure is a structure in which a compression mechanism, a drive shaft, an electric motor, etc. are housed in a sealed container. It is used.

  Here, a conventional technology will be described by taking a scroll compressor for heat pump hot water supply or an air conditioner used for carbon dioxide (carbon dioxide) refrigerant gas, which is a natural refrigerant, as an example. First, the structure will be described with reference to a longitudinal sectional view of a conventional scroll compressor shown in FIG. The hermetic container 1 is constituted by a cylindrical shell shell 21a, and its upper and lower shells 21b and 21c are welded at their ends so that refrigerant gas does not leak, and further, a refrigerant gas suction pipe 11 and a discharge pipe 16 are provided. The terminals 25 for energization of the motor 7 are fixedly installed so that the refrigerant gas does not leak by welding or brazing.

  Inside the hermetic container 1 are a compression mechanism 2 composed of a fixed scroll 2a and a movable scroll 3, a shaft 5 for rotating the movable scroll 3 with respect to the fixed scroll 2a via an Oldham joint 4, and a fixed scroll. A bearing member 6 that fixes the shaft 2a and rotatably supports the shaft 5 is installed. The bearing member 6 is fixed to the sealed container 1 by welding or the like. Below the bearing member 6, a rotor 7a fixed to the shaft 5 and a stator 7b fixed to the shell shell 21a by shrink fitting or the like are installed.

  Further, an oil sump 10 for storing the lubricating oil 9 is provided at the bottom inside the sealed container 1, and the lubricating oil 9 in the oil sump 10 is oiled from the lower end of the through hole 13 of the shaft 5 as the shaft 5 rotates. It is sucked up by the pump 17 and is supplied to each sliding surface such as the journal bearing 6a, the eccentric bearing 3a, and the fixed scroll 2a and the movable scroll 3. The journal bearing 6a and the eccentric bearing 3a are composed of the bearing member 6 and bearing bushes 8a and 8b press-fitted into the movable scroll 3, and maintain durability and sliding characteristics. For the bearing bushes 8a and 8b, a sliding coating layer (for example, a resin such as Teflon (registered trademark), polyimide, polyamide, graphite, glass fiber, hard carbon, etc.) on the inner peripheral surface of a cylindrical back metal (SPCC, etc.) So-called resin-impregnated bearing bushes with a back metal formed on the back.

  Next, the refrigerant gas compression cycle will be described. The low-pressure refrigerant gas that has circulated through the heat exchanger (not shown) of the air conditioner is absorbed by the compression mechanism unit 2 through the suction pipe 11. The sucked refrigerant gas enters a crescent-shaped compression space (not shown) formed between the fixed scroll 2 a and the movable scroll 3, and the crescent-shaped compression space is moved from the outside by the turning motion of the movable scroll 3. By gradually shrinking toward the center, the refrigerant gas is compressed and becomes a high-pressure gas, and is discharged from the discharge hole 12 provided in the center portion of the fixed scroll 2a.

The high-pressure gas discharged from the discharge hole 12 is once discharged into the discharge space 1a above the fixed scroll 2a in the hermetic container 1 and flows to the space 1b above the movable element 7a through the gas passage 14, and then inside the rotor 7a. From the gas passage 18a provided to the closed space 1 to the bottom space 1c of the hermetic container 1 and further upward through the passage 18b provided on the outer periphery of the stator 7b to the stator upper space 1d and provided separately from the passage 14. After flowing out into the upper space 1e of the fixed scroll 2a through the gas passage 15, it is discharged and conveyed from the discharge pipe 16 to a heat pump system such as an external heat exchanger (not shown). The high pressure gas is circulated through a heat exchanger or the like, and becomes a low pressure gas. The high pressure gas returns to the compressor from the suction pipe 11 and circulates a known heat pump cycle.

  Next, the circulation cycle of the lubricating oil 9 inside the compressor will be described. The lubricating oil 9 is sucked up by the oil pump 17 from the oil sump 10, rises through the through hole 13 of the shaft 5, and exits from the gap of the eccentric bearing 3 a to the boss part space 19 in which the boss part of the movable scroll 3 is accommodated. Through the gap of the journal bearing 6a, the oil is discharged from the oil discharge port below the journal bearing 6a to the space 1b above the mover 7a. Then, it returns to the oil sump 10 at the bottom through the passage 18a in the mover 7a. Part of the lubricating oil 9 that has passed through the eccentric bearing 3a is partly from the boss space 19 to the back pressure space 22 where the Oldham coupling 4 is installed, and the suction back pressure adjusting valve 23 that adjusts the pressure in the back pressure space 22. To the compression chamber 24 on the suction side. Thereafter, the lubricant oil is compressed together with the refrigerant gas by the orbiting movement of the movable scroll 3 and exits from the discharge hole 12, and passes through the same path as the previous refrigerant gas, and the lubricating oil that has exited from the lower portion of the previous journal bearing 6 a in the stator upper space 1 b. And return to the sump 10 at the bottom. By these circulation cycles of the lubricating oil, the sliding portions such as the shaft 5, the eccentric bearing 3a, the journal bearing 6a, the Oldham coupling 4, the movable scroll 3, the fixed scroll 2a, and the like are lubricated.

  In recent years, in order to suppress global warming, HFC refrigerants (for example, HFc type mainly composed of R410A or R32, etc.) are used in place of CFCs such as R12 and HCFC refrigerants such as R22, which have been conventionally used as refrigerants. The use of equipment using natural refrigerants such as refrigerants) and carbon dioxide (hereinafter referred to as CO2) has been promoted, and improvement in efficiency has been demanded. However, these refrigerants have higher operating pressure than the conventional refrigerants due to the characteristics of the refrigerants, so that the sliding portion slides while receiving a large force according to the pressure. In addition, the HFC refrigerant has no chlorine that had a lubricating action in the HCFC system, and the natural refrigerant CO2 has a strong cleaning action, both of which have disadvantages in terms of lubrication compared to conventional HCFC refrigerants. In other words, it is effective in suppressing global warming, but has problems in improving reliability and efficiency.

  FIG. 5 is an enlarged cross-sectional view of a conventional sliding portion. The movable scroll 3 makes a turning motion while receiving and thrusting a load in the thrust direction toward the fixed scroll 2a due to the pressure in the boss portion space 19 and the back pressure space 22 from below, and the thrust load is applied to the compression chamber of the fixed scroll 2a. The thrust surface 52b and the wrap end surface 53a (upper surface in the drawing) of the movable scroll 3 and the wrap end surface 52a (lower surface in the drawing) of the fixed scroll 2a and the compression chamber thrust surface 53b of the movable scroll 3 are similarly slid with each other. doing.

  Further, the key portion 4a of the Oldham joint 4 and the key groove portion 3b of the movable scroll 3 and the key portion of the Oldham joint 4 and the key groove portion of the bearing member 6 (not shown) slide against each other while receiving the load in the rotational direction. Yes.

  When the compressor configured as described above is used for a CO2 refrigerant heat pump cycle, since the differential pressure operation is higher than that of the conventional refrigerant, the sliding surfaces are partially separated by an excessive load received by the sliding portion of the scroll and Oldham joint. It becomes easy to be in a mixed lubrication state in contact with (close to boundary lubrication). When this mixed lubrication state (close to boundary lubrication) continues, wear and seizure occur at the sliding portion.

In a conventional scroll compressor, the movable scroll 3 is formed of an aluminum alloy material to cope with weight reduction and high-speed rotation, and the fixed scroll 2 uses cast iron material and the Oldham ring uses iron-based sintered material. An anodized layer is formed on the surface 3 for the purpose of improving wear resistance (see, for example, Patent Document 1). FIG. 6 is a cross-sectional view of a conventional movable scroll that has been anodized. As shown by the dotted lines in FIG. 6, an anodized layer is formed on almost the entire surface (53a, 53b, 53c, 53d, 53e, etc.). In the anodic oxidation treatment, a movable scroll is immersed in an electrolytic solution, and a film is formed by being energized through an electrode 137 from a processing power source 136 as shown in FIG. In order to prevent the bush 103 having the back metal from being corroded by the intrusion of the electrolytic solution, the boss portion is covered with a masking 135.

JP 2006-112379 A

  However, the anodized layer is easily cracked during processing, and has a problem that wear resistance and lubricity are impaired. The present invention solves the above-described conventional problems, and an object thereof is to provide a method of manufacturing a fluid machine that realizes reliability and performance improvement using a sliding member having high wear resistance and lubrication performance. To do.

  In order to achieve the above object, in the present invention, a crack-free coating is formed on the surface of a sliding member mainly composed of aluminum by controlling the process during anodizing. Thereby, a highly reliable film can be formed.

  According to the fluid machine manufacturing method of the present invention, it is possible to realize a sliding member having excellent wear resistance and sliding characteristics, and also to realize a fluid machine manufacturing method having excellent durability and high efficiency.

Sectional drawing of the surface of the movable scroll in Embodiment 1 Flowchart diagram of an anodic oxidation process in the first embodiment SEM photograph of conventional anodized film and anodized film in embodiment 1 of the present invention Longitudinal sectional view of a conventional scroll compressor Expanded sectional view of a conventional sliding part Cross section of a conventional movable scroll

  1st invention is the manufacturing method of the fluid machine which forms an anodic oxide film in the sliding member surface, Comprising: The process of forming the said anodic oxide film is a pre-processing process which wash | cleans a raw material, and electrolysis temperature is 20 degreeC. As described above, by providing the anodizing treatment step for electrolysis at a film thickness of 4 μm or less and the sealing drying step for treatment at a sealing drying temperature of 80 ° C. or less, the growth of the film becomes constant and there is no cracking. A film can be formed.

  In the second invention, the sliding member is mainly composed of aluminum and contains silicon particles in an amount of 5% to 15%, so that the manufacturing cost can be reduced and the mechanical strength can be improved.

3rd invention is a fluid machine which has a scroll type compression mechanism part, Comprising: When the said sliding member is a movable scroll or a fixed scroll, there exists an effect similar to 1st invention.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
A case where an anodized film (alumite layer) having no cracks is formed on the movable scroll 3 made of aluminum and an aluminum alloy containing 5 to 15% Si particles will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of the surface of the movable scroll according to Embodiment 1 of the present invention. FIG. 2 is a flowchart of the anodizing process in the first embodiment. FIG. 3 is a SEM photograph of the conventional anodic oxide film and the anodic oxide film in Embodiment 1 of the present invention.

  FIG. 1 shows a surface layer cross section after anodizing treatment according to the present embodiment, and the material of the movable scroll 3 is an aluminum alloy. The Si particles 31 are particles having an average diameter of about 3 to 5 μm. 32 is a sliding surface, and 35a is an anodized film. Since the Si particles 31 are less conductive than the aluminum part, gaps 36 are generated around the Si particles 31 during the growth process of the anodized film 35a. Here, the anodic oxidation treatment was an alumite sulfate treatment at 25 ° C., the thickness σa was about 3 μm, and the average diameter of the Si particles 31 was 5 μm. The anodized film 35a has a columnar structure, has a hollow portion along the columnar shape, and is connected from the upper surface of the film to the lower part of the film (aluminum substrate).

  In addition, it is effective not only in the case of 5-15% Si aluminum alloy but also in the case of a material containing 15% or more, but the manufacturing cost of the material is high and the mechanical strength is low, and anodization The formation rate of the layer is low, the productivity is low and it is not realistic. On the other hand, it goes without saying that an effect can be obtained even at 5% or less.

  It should be noted that the silicon average particle diameter is not limited to 3 to 5 μm, and it goes without saying that the present invention can be applied even when the particle diameter is larger or smaller.

  According to the above configuration, since the anodic oxide film 35a having excellent wear properties can be formed on the sliding portion of the movable scroll 3 that is a sliding member without breaking, the loss of the sliding portion is reduced and the wear resistance is improved. realizable. Further, by using the movable scroll 3 formed with the oxide film in the scroll compressor which is a fluid machine, it is possible to improve efficiency, durability and reliability.

The movable scroll 3 is completed by forming a desired anodized film 35a on the surface thereof in the anodizing process shown in FIG.
(Step 1) This is a pretreatment step, and the material is washed (acid washing, alkali washing) to remove impurities from the surface.
(Step 2) An anodic oxidation electrolytic treatment step in which an anodized film 35a, which is an aluminum oxide layer, is formed on the pretreated surface. During electrolysis, electrolysis is performed at a constant current, a temperature of 20 ° C. or more, and a film thickness of 4 μm or less, whereby an elastic film can be formed uniformly and an anodic oxide film (alumite layer) without cracks is formed.
(Step 3) This is a sealing treatment step, which is a step of oxidizing and sealing the pore portions of the formed anodized film 35a.
(Process 4) It is a drying process, and is a process of drying at a temperature of 80 ° C. or lower together with the sealing process.

  From FIG. 3, it is confirmed that the anodized film 35a produced by this process has prevented the surface from being cracked due to thermal expansion.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. When a cast iron material is used for the movable scroll 3 and the bearing member 6 and an aluminum alloy material is used for the Oldham joint 4, an oxide film is formed on the sliding portion of the Oldham joint 4 in the same manner as in the first embodiment. Loss reduction and improved wear resistance. Moreover, the scroll compressor which is a fluid machine using the Oldham coupling 4 can realize improvement in efficiency, durability and reliability.

  As described above, in the first and second embodiments, the case where the scroll type compression mechanism is provided has been described as an example. However, other rotary type, reciprocating type compressors, expanders, pumps, and heat engines that do not have an engine, etc. Needless to say, the present invention can be applied to the above, and the same effect can be realized. Especially in car compressors and engines that are required to be smaller and lighter, aluminum alloys are often used for sliding parts and anodization is often required. In addition, the present invention can be more effective. Needless to say, both sliding members that slide relative to each other are made of an aluminum alloy, and an oxide film may be similarly formed on one or both.

  The scroll compressors according to the first and second embodiments of the present invention will be described by taking as an example the case where CO2 is used as refrigerant and PAG oil is used as lubricating oil. However, the present invention is not limited to this, and HFC refrigerants R410A and R32 are used. Alternatively, the present invention can be similarly applied to the case where a refrigerant such as hydrocarbon (HC) or HCFC22 and ether, ester, PAO, alkylbenzene, mineral oil, or the like is used for the lubricating oil, and the same effect can be obtained.

  As described above, according to the sliding member and the fluid machine according to the present invention, a sliding member having excellent wear resistance and sliding characteristics can be realized, and a fluid machine having excellent durability and high efficiency can be realized. Since it can be realized, it should be applied to applications such as engines in addition to refrigerant compressors used in refrigeration equipment such as air conditioners and refrigerators, dehumidifiers and dryers, and water heater heat pump applications. Can do.

3 Movable scroll 31 Si particle 32 Sliding surface 35a Anodized film 36 Gap

Claims (3)

A fluid machine manufacturing method for forming an anodized film on a sliding member surface,
The step of forming the anodized film comprises
A pretreatment process for cleaning the material;
An anodizing treatment step of electrolyzing at an electrolysis temperature of 20 ° C. or more and a film thickness of 4 μm or less;
A method for manufacturing a fluid machine, comprising: a sealing drying process for performing a sealing drying temperature of 80 ° C. or less. 2. The method of manufacturing a fluid machine according to claim 1, wherein the sliding member contains aluminum as a main component and contains 5% to 15% of silicon particles. 3. The fluid machine manufacturing method according to claim 1, wherein the fluid machine has a scroll type compression mechanism, and the sliding member is a movable scroll or a fixed scroll.