JP2007205335A - Swash plate of swash plate compressor and swash plate compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swash plate of a swash plate compressor made of a metal base material made usable also for a swash plate compressor in which carbon dioxide gas is used as a refrigerant by covering it with a lubricating film excellent in anti-seizure property, adhesiveness, and wear resistance. <P>SOLUTION: A lubricating film 11 made of a fluororesin, a heat resistant resin, and a metal oxide powder is formed on the surface of the metal base material 3a forming the swash plate 3. A porous thermal spray layer 10 is formed between the lubricating film 11 and the metal base material 3a to increase the adhesiveness of the lubricating film 11 by the anchor effect on the porous thermal spray layer 10. Since sufficient anti-seizure property and wear resistance can be secured on the sliding surface of the swash plate by the lubricating film 11 made of the fluororesin, the heat resistant resin, and the metal oxide powder which is excellent in friction and wear characteristics, the swash plate can also be used as a swash plate compressor in which carbon dioxide is used as a refrigerant. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a swash plate compressor and a swash plate compressor used for an air conditioner or the like.

  In the housing where the refrigerant is present, the shoe is slid on the swash plate attached obliquely so as to be directly fixed to the rotating shaft or indirectly through the connecting member, and the swash plate rotates through this shoe. The swash plate compressor that compresses and expands the refrigerant into the reciprocating motion of the piston includes a double swash plate type that compresses and expands the refrigerant on both sides using a double-headed piston, and a single-headed piston. There is a swash plate type that compresses and expands the refrigerant only on one side. In addition, there are shoes that slide on only one side of the swash plate and those that slide on both sides of the swash plate.

  In these swash plate compressors, the metal swash plate and the shoe slide in the initial stage of operation before the lubricating oil reaches the housing in which the refrigerant exists. It becomes a state and seizure is likely to occur. As means for preventing this seizure, so far, a copper-based or aluminum-based metal material is sprayed on the sliding surface of the metal swash plate on which the shoe slides, and this metal sprayed layer is lead-plated, Tin-based plating, lead-tin-based plating, polytetrafluoroethylene (PTFE) -based coating, molybdenum disulfide coating or molybdenum disulfide-graphite mixed coating (for example, see Patent Document 1), aluminum or iron-based A swash plate having a base material, an intermediate layer mainly composed of tin, copper or metal phosphate, and a sliding contact layer including a thermosetting resin and at least one solid lubricant selected from molybdenum disulfide and graphite ( For example, Patent Document 2) has been proposed.

Japanese Patent Laid-Open No. 8-199327 Japanese Patent Laid-Open No. 11-13638

  In a swash plate type compressor that uses carbon dioxide gas as a refrigerant, which has been developed in recent years, the pressure in the compressor reaches as high as 10 MPa, so the sliding pressure between the swash plate and the shoe is higher than before. The formed swash plate film is required to have better adhesion and wear resistance.

  However, the conventional swash plate described in Patent Documents 1 and 2 is not suitable for a swash plate compressor that uses carbon dioxide gas as a refrigerant and the pressure in the compressor reaches 10 MPa. There is a problem that the wear resistance cannot be ensured and the durability is not sufficient.

  Accordingly, an object of the present invention is to coat a swash plate formed of a metal substrate of a swash plate compressor with a lubricating film having excellent adhesion and wear resistance as well as seizure resistance, and using carbon dioxide as a refrigerant. The swash plate compressor to be used should also be durable.

  In order to solve the above-described problems, the present invention slidably slides a shoe on a swash plate attached obliquely so as to be directly fixed to a rotating shaft or indirectly through a connecting member in a housing in which a refrigerant exists. In the swash plate of the swash plate compressor that compresses and expands the refrigerant by converting the rotational motion of the swash plate to the reciprocating motion of the piston through this shoe, the swash plate is formed of a metal substrate, A lubricious coating made of fluororesin, heat-resistant resin and metal oxide powder is formed on the sliding surface on which the shoe slides, and a porous sprayed layer is formed between the lubricating coating and the metal substrate. The configuration was adopted.

  That is, a swash plate is formed of a metal base material, and a lubricating film made of a fluororesin, a heat-resistant resin and a metal oxide powder is formed on a sliding surface on which the shoe slides. By forming a porous sprayed layer with the base material, the anchoring effect to the porous sprayed layer increases the adhesion of the lubricating coating, and the fluororesin, heat resistant resin and metal oxide with excellent frictional wear characteristics The lubricant film made of the product powder ensures sufficient seizure resistance and wear resistance on the sliding surface, and can be used for a swash plate compressor using carbon dioxide as a refrigerant.

  The porous sprayed layer can enhance the adhesion of the lubricating coating by the anchor effect of the resin of the lubricating coating entering the fine pores, and as the sprayed metal, Cu, Sn, Al, Ni, Mo, Fe and the like, and alloys thereof can be used.

The fluororesin that forms the lubricating film has a low friction characteristic and serves to impart seizure resistance to the film. The fluororesin is not particularly limited as long as it has heat resistance capable of withstanding temperature rise at the sliding portion with the shoe. Specifically, PTFE (melting point θ _M : 327 ° C., continuous use temperature θ _A : 260 ° C. ), Tetrafluoroethylene-hexafluoropropylene copolymer (θ _M : 270 ° C., θ _A : 200 ° C.), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (θ _M : 310 ° C., θ _A : 260 ° C.) , Tetrafluoroethylene-ethylene copolymer (θ _M : 270 ° C., θ _A : 150 ° C.), polychlorotrifluoroethylene (θ _M : 210 ° C., θ _A : 120 ° C.), ethylene-chlorotrifluoroethylene copolymer And coalesced (θ _M : 240 ° C, θ _A : 150 ° C). These may be used singly or in combination of two or more types of copolymers or tricopolymers.

Among these, PTFE is composed of repeating units of —CF ₂ CF ₂ —, has a high melt viscosity of about 10 ¹⁰ to 10 ¹¹ Pa · s even at 340 to 380 ° C., and hardly flows even when the melting point is exceeded. Among these, heat resistance is most excellent, and excellent sliding property is exhibited even at room temperature. Furthermore, among PTFE, it is preferable to use a lubricant grade powder PTFE, and examples of commercially available lubricant grade powder PTFE include Polyflon M15, Lubron L-2 (trade name, manufactured by Daikin Industries), Teflon TLP-10 ( DuPont brand name), Fullon G163 (Asahi Glass brand name) and the like. Note that the lubricant-grade powder PTFE means regenerated PTFE obtained by pulverizing PTFE that has been fired once, PTFE powder that has been subjected to gamma ray irradiation treatment to reduce the molecular weight, and examples of commercially available products that have been subjected to gamma ray irradiation treatment include: There is KT400H (Kitamura Co., Ltd. trade name).

  The form of the PTFE may be a molding powder or a so-called fine powder for a solid lubricant, and its average particle size is in the range of 0.1 to 20 μm, preferably 0.2 to 10 μm. There should be. When the average particle size is within this range, it is difficult to agglomerate in the coating agent, and it is uniformly distributed in the film.

  The heat-resistant resin firmly adheres to the porous sprayed layer without thermally degrading the coating, and serves to bind the fluororesin or metal oxide powder as a powder. Examples of the heat resistant resin include a polyimide resin, an epoxy resin, a phenol resin, a silicone resin, and the like. Among them, the polyimide resin is most excellent in heat resistance and adhesion.

  Specific examples of the polyimide resin include a polyimide resin (PI), a polyamideimide resin (PAI), a polyesterimide resin, a polyesteramideimide resin, and the like. Among them, PI and PAI are preferable. An aromatic polyimide resin or an aromatic polyamideimide resin in which a bond or an amide bond is bonded via an aromatic group is particularly preferable.

  The PAI is a resin having an imide bond and an amide bond. Moreover, the imide bond of the aromatic polyamideimide resin may be a precursor such as polyamic acid, a closed imide ring, or a mixture of these. Such an aromatic polyamideimide resin is produced from an aromatic primary diamine (for example, diphenylmethanediamine) and an aromatic tribasic acid anhydride (for example, a mono- or diacyl halide derivative of trimet acid anhydride). And those produced from an aromatic diisocyanate compound (for example, diphenylmethane diisocyanate) and an aromatic tribasic acid anhydride. Furthermore, it is produced from an aromatic, aliphatic or alicyclic diisocyanate compound and an aromatic tetrabasic acid dianhydride and an aromatic tribasic acid anhydride as PAI having a higher ratio of imide bonds than amide bonds. Any PAI can be used.

  The metal oxide powder serves to improve the wear resistance of the film, and powders of iron oxide, titanium oxide, magnesium oxide, aluminum oxide, and the like can be used.

  As a method for forming the above-described lubricating coating on the surface of the porous sprayed layer, the coating agent having the above-described configuration is applied to the surface of the porous sprayed layer by dipping, spray coating, brush coating, powder coating, or the like. The method of apply | coating to this and baking this can be employ | adopted. When the coating agent is applied by the spray coating method, the coating agent becomes fine particles and adheres to the surface of the porous sprayed layer, so that the thickness of the coating can be managed with high accuracy.

  The coating agent can be obtained by dispersing or dissolving a fluororesin, a heat-resistant resin, and a metal oxide powder in a solvent except when a powder coating method is employed. Solvents include ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, aromatic hydrocarbons such as toluene and xylene, and organic halogenated compounds such as methyl chloroform, trichloroethylene and trichlorotrifluoroethane. Aprotic polar solvents such as NMP, DMAC, methylisopyrrolidone (MIP), and dimethylformamide (DMF) can be used. The powder coating method is solventless coating.

  The film thickness of the lubricating coating applied to the porous sprayed layer by these methods is 5 to 40 [mu] m, preferably 10 to 30 [mu] m in thickness after firing. If the film thickness is less than 5 μm, local wear may occur when the shoe comes into contact with each other, and if the film thickness exceeds 40 μm, peeling of the film tends to occur.

  The firing temperature of the lubricating film varies depending on the type of heat resistant resin constituting the coating agent, but when the heat resistant resin is PI, 200 to 350 ° C. is appropriate. If the firing temperature is less than 200 ° C., the imide reaction of the polyamic acid that is the precursor is not sufficient, and there is a possibility that sufficient adhesion with the porous sprayed layer may not be ensured. This is because it begins to decompose.

  When the heat resistant resin is PAI, the baking temperature of the film is suitably 180 to 280 ° C. When the firing temperature is less than 180 ° C., the PAI curing reaction does not proceed so much, so that sufficient adhesion with the porous sprayed layer and the metal substrate cannot be ensured, and when it exceeds 280 ° C., the fluororesin exceeds the melting point. Because it begins to decompose. Further, since the adhesiveness of the PAI with the porous sprayed layer reaches an equilibrium state at around 280 ° C., it is preferable to calcinate at 280 ° C. or lower in consideration of the temperature rise energy.

  The porous coating layer is formed by using 100 to 150 parts by weight of the heat-resistant resin and 5 to 20 parts by weight of the metal oxide powder with respect to 100 parts by weight of the fluororesin. It is possible to exhibit better adhesion and wear resistance. If the heat resistant resin is less than 100 parts by weight with respect to 100 parts by weight of the fluororesin, the adhesiveness is lowered, and if it exceeds 150 parts by weight, the sliding characteristics are lowered. Further, if the amount of the metal oxide powder is less than 5 parts by weight with respect to 100 parts by weight of the fluororesin, the wear resistance is insufficient, and if it exceeds 20 parts by weight, the adhesion is deteriorated.

  By using the iron oxide powder as the metal oxide powder, the wear resistance can be further improved, which is advantageous in terms of availability and cost.

  As the iron oxide powder, iron oxide (II), ferric trioxide, triiron tetroxide and the like can be used, and the powder shape of these iron oxides is any of spherical, scaly, acicular, etc. It may be a shape. The average particle diameter of the iron oxide powder may be any particle diameter, for example, about 0.1 to 10 μm, but is preferably 0.1 to 1 μm, more preferably 0.2 to 0.5 μm. When the average particle size is less than 0.1 μm, the particles are easily aggregated and the dispersibility is deteriorated. When the average particle size is more than 1 μm, the wear resistance of the film becomes slightly nonuniform. The average particle diameter of the iron oxide powder can be measured by the BET method, but is not particularly limited to this measurement method.

  The present invention also employs a configuration in which the swash plate compressor is provided with any of the swash plates described above.

  Even if the swash plate compressor uses carbon dioxide gas whose pressure in the compressor reaches 10 MPa as a refrigerant, the metal base film of the swash plate has excellent adhesion and wear resistance and is sufficiently durable. Can be possible.

  The swash plate of the swash plate compressor according to the present invention is formed by forming a swash plate with a metal base material, and forming a lubricating film made of fluororesin, heat-resistant resin and metal oxide powder on the sliding surface on which the shoe slides. By forming a porous sprayed layer between this lubricating coating and the metal substrate, the adhesion of the lubricating coating is enhanced by the anchor effect on the porous sprayed layer, and the fluororesin has excellent friction and wear characteristics. In addition, the lubricant film made of heat-resistant resin and metal oxide powder ensures sufficient seizure resistance and wear resistance on the sliding surface, so it can be used for swash plate compressors that use carbon dioxide as a refrigerant. It can be.

  Adhesiveness with a metal base material by using 100 to 150 parts by weight of heat-resistant resin and 5 to 20 parts by weight of metal oxide powder for 100 parts by weight of the fluororesin. And better wear resistance.

  By using the iron oxide powder as the metal oxide powder, the wear resistance can be further improved, which is advantageous in terms of availability and cost.

  Further, since the swash plate compressor of the present invention is provided with the swash plate described above, even if it is used in a swash plate compressor that uses carbon dioxide gas as a refrigerant, the pressure in the compressor reaches 10 MPa, it can be sufficiently used. Can be.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This swash plate type compressor uses carbon dioxide gas as a refrigerant, and as shown in FIG. 1, a rotary motion of a swash plate 3 attached obliquely so as to be directly fixed to a rotary shaft 2 in a housing 1 where the refrigerant exists. Is converted into a reciprocating motion of a double-headed piston 5 through shoes 4 sliding on both side surfaces of the swash plate 3, and on both sides of each piston 5 in a cylinder bore 6 formed at equal intervals in the circumferential direction of the housing 1. The rotary shaft 2 that is a swash plate type that compresses and expands the refrigerant and is driven to rotate at high speed is supported by the needle roller bearing 7 in the radial direction and supported by the thrust needle roller bearing 8 in the thrust direction. Has been.

  Each piston 5 is formed with a recess 5a so as to straddle the outer periphery of the swash plate 3, and a hemispherical shoe 4 is seated on a spherical seat 9 formed on the axially opposed surface of the recess 5a. The shoe 4 is also spherical and supports the piston 5 so as to be movable relative to the rotation of the swash plate 3. Thereby, the conversion from the rotational movement of the swash plate 3 to the reciprocating movement of the piston 5 is performed smoothly.

  The base material 3a of the swash plate 3 is made of steel S45C, and as shown in FIG. 2, porous sprayed layers 10 of copper alloy are formed on both side surfaces of the base material 3a on which the shoe 4 slides. On top of that, a lubricating film 11 made of PTFE as a fluororesin, PAI as a heat resistant resin, and iron oxide or titanium oxide as a metal oxide powder is formed.

As an example, as shown in Table 1, a porous thermal spray layer of copper alloy of 95% by mass of Cu and 5% by mass of Sn is formed on one side of a steel disk, and consists of powders of PTFE, PAI and iron oxide. The test piece (Examples 1-3) which formed the lubricity film | membrane from which the compounding ratios differed, and the test piece (Example 4) which formed the lubricity film which consists of a powder of PTFE, PAI, and a titanium oxide were prepared. In addition, as a comparative example, without forming the above-mentioned porous sprayed layer, a coating agent in which copper powder and molybdenum disulfide (MoS ₂ ) are blended in place of the metal oxide powder of iron oxide or titanium oxide is used. A test piece (Comparative Examples 1 and 2) on which a lubricating film was formed in the same manner as in each example was also prepared. In addition, the numerical value in Table 1 is the value of the weight part of each composition with respect to 100 weight part of PTFE.

  Two types of friction and wear tests (tests 1 and 2) using a thrust type tester (3 shoe-on-type) that slides three steel shoes on each of the test pieces of the above-mentioned examples and comparative examples. The friction coefficient of the sliding part at the beginning of the test and after 5 minutes, and the wear amount and temperature of the sliding surface of the test piece after 5 minutes were measured. The test conditions for each test 1 and 2 are as follows.

  The results of the friction and wear test are also shown in Table 1. In Examples 1 to 4 in which a porous sprayed layer was formed between the metal substrate and the lubricious coating, and the metal oxide powder was blended in the lubricious coating, the lubrication condition of the sliding surface was in a dry state. In both Test 1 and Test 2 in which the sliding surface pressure was increased to 10 MPa, it was confirmed that the wear amount was small and excellent wear resistance was obtained. In addition, although the thing of each Example does not have so much difference in the measurement data of the friction coefficient and the amount of wear, the result of visually observing the sliding surface after each test is the best in Example 3. Hereinafter, the order was Example 2, Example 4, and Example 1.

  On the other hand, each of Comparative Examples 1 and 2 in which the porous sprayed layer was not formed and the metal oxide powder was not blended in the lubricious coating had a large amount of wear and sufficient wear resistance. It was not obtained. Further, the lubricating film of Comparative Example 1 in Test 2 did not peel off from the metal substrate, but slight interface peeling occurred.

  In the above-described embodiment, the swash plate type swash plate compressor is configured such that the shoes slide on both sides of the swash plate. However, the swash plate of the swash plate compressor according to the present invention is of a swash plate type. In addition, the present invention can be applied to all types of swash plate compressors such as a shoe that slides only on one side of a swash plate, and a swash plate that is attached to a rotating shaft via a connecting member.

A longitudinal sectional view showing an embodiment of a swash plate compressor Sectional drawing which expands and shows the swash plate of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Rotating shaft 3 Swash plate 4 Shoe 5 Piston 5a Recess 6 Cylinder bore 7 Needle roller bearing 8 Thrust needle roller bearing 9 Spherical seat 10 Porous sprayed layer 11 Lubrication film

Claims (5)

  In the housing where the refrigerant is present, the shoe is slid on the swash plate attached obliquely so as to be directly fixed to the rotating shaft or indirectly through the connecting member, and the swash plate is rotated through this shoe. In the swash plate of the swash plate type compressor that converts the movement into the reciprocating motion of the piston and compresses and expands the refrigerant, the swash plate is formed of a metal base material, and the sliding surface on which the shoe slides has a fluororesin, A swash plate for a swash plate compressor, wherein a lubricious coating comprising a heat-resistant resin and a metal oxide powder is formed, and a porous sprayed layer is formed between the lubricating coating and the metal substrate.   2. The swash plate compressor according to claim 1, wherein the lubricating coating is 100 to 150 parts by weight of the heat resistant resin and 5 to 20 parts by weight of the metal oxide powder with respect to 100 parts by weight of the fluororesin. Swash plate.   The swash plate for a swash plate compressor according to claim 1 or 2, wherein the metal oxide powder is iron oxide powder.   A swash plate compressor comprising the swash plate according to any one of claims 1 to 3.   The swash plate compressor according to claim 4, wherein the swash plate compressor uses carbon dioxide as a refrigerant.

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