JP2007205323A - Swash plate compressor and its swash plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swash plate of a swash plate compressor in which a resin layer on the shoe sliding surface of the swash plate sufficiently develops the friction characteristic specific to a fluororesin and has wear resistance, and seizure is hard to occur even under dry lubricating state in which a lubricating oil is absent. <P>SOLUTION: A film composed of a resin composition formed by mixing a 10 to 100 pts.wt fluororesin such as PTFE and ETFE and a 20 to 100 pts.wt aromatic polyester resin in a 100 pts.wt polyphenylene sulfide resin is formed on the shoe contact surface of the swash plate 3 of the swash plate compressor. The film has a heat resistance of 300°C or higher, sufficiently develops the abrasive characteristics of the fluororesin, has excellent abrasive characteristic and wear resistance even under the high load use condition of 5 to 10 kgf/cm<SP>2</SP>or higher, and is hard to be seized even under dry lubricating state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a swash plate type compressor used for a heat medium compressor of an air conditioner, and the swash plate.

  In general, a swash plate compressor is known as a compressor (compressor) for a working fluid such as a refrigerant used in a heat exchange cycle of an air conditioner or the like.

  The structure of a typical swash plate compressor will be described with reference to FIG. 1. A rotary shaft 2 to which a driving force is input is provided in a compressor housing (cylinder block) 1 for compressing a working fluid. On the other hand, a disk-like swash plate (also referred to as a swash plate) 3 is fixed directly at an angle, or indirectly attached via a connecting member and rotates integrally. The shoe 4 is disposed so as to slidably contact the periphery of the swash plate 3 from both sides, and is composed of a pair of hemispherical sliding parts. The shoe 4 is slidably contacted with a spherical seat 6 formed in the concave portion 5a of the piston 5 and is held so that the inclination angle can be changed. The piston 5 is converted into an axial reciprocating motion via the shoe 4. The piston 5 reciprocates to pressurize or depressurize the working fluid in the cylinder bore 7.

  The normal swash plate 3 in such a swash plate compressor is made of an iron-based metal material, and this slides in a state where the shoe 4 is in pressure contact, and therefore the lubricating oil tends to be insufficient on the sliding surface. Further, in the initial stage of operation, the metal swash plate and the shoe slide before the lubricating oil reaches the housing where the refrigerant exists, so that these sliding portions are in a dry lubricating state without the lubricating oil. When such a lack of lubrication occurs, the sliding surfaces of the shoe 4 and the swash plate 3 are worn away, and the swash plate 3 and the shoe 4 may eventually be seized.

  In order to prevent such seizure, it is necessary to improve the slidability of the swash plate 3 in contact with the shoe 4, and a solid surface containing polytetrafluoroethylene (PTFE) on the sliding surface of the swash plate 3 with the shoe 4. There is known one provided with a sliding layer in which a lubricant is dispersed and held in a thermosetting polyamide-imide resin (PAI) (Patent Document 1).

JP 2003-138287 A

  However, in the above-described conventional swash plate compressor, the swash plate base material and the sliding layer are not sufficiently bonded, and the PAI layer has water absorption, so the strength of the sliding layer is reduced by water absorption. However, there is a problem that the durability is not sufficiently exhibited.

  Further, since the glass transition temperature of PAI is about 280 to 290 ° C., there is a problem that heat resistance cannot be sufficiently maintained if the sliding portion generates heat in a dry lubrication state where no lubricating oil is present.

When a paint in which a fluororesin such as PTFE is dispersed and held in a binder resin such as PAI is applied to the swash plate, the binder resin is shifted to the base side due to the energy difference of the surface, so that the adhesion is improved and the PTFE moves to the surface layer side. Although its low friction characteristics are exhibited, its friction characteristics and wear resistance are not sufficient under high load conditions of 5 to 10 kgf / cm ² or more in the use state of the swash plate.

  Further, since the binder resin is mixed with the fluororesin on the surface layer, the low friction characteristic inherent to the fluororesin did not sufficiently appear on the sliding surface of the swash plate.

  Therefore, the object of the present invention is to solve the above-described problems, the resin layer on the sliding surface of the shoe of the swash plate sufficiently exhibits the inherent friction characteristics of the fluororesin, and has wear resistance. A swash plate of a swash plate type compressor that hardly seizes even under dry lubrication conditions in which no lubricating oil is present.

  In order to solve the above problems, in the present invention, a shoe is attached to an obliquely attached swash plate so as to be directly fixed to a rotating shaft or indirectly through a connecting member in a housing in which a refrigerant exists. The swash plate slides on the swash plate of the swash plate compressor that compresses and expands the refrigerant by converting the rotational movement of the swash plate into the reciprocating motion of the piston through the shoe. A swash plate of a swash plate compressor characterized in that a coating made of a resin composition in which a fluororesin is added with polyphenylene sulfide resin (PPS) as a main component is provided on the surface.

The swash plate of the swash plate compressor according to the present invention configured as described above has a coating provided on the sliding surface of the shoe as a resin composition to which a fluororesin is added with PPS as a main component. It has a heat resistance of ℃ or higher and sufficiently exhibits the friction characteristics of fluororesin, and is excellent in friction characteristics and wear resistance even under high load conditions of 5 to 10 kgf / cm ² or more in the state of use of the swash plate. It becomes a swash plate of a swash plate type compressor which is hard to be seized even in dry lubrication conditions where no lubricating oil is present.

More desirably, the film is formed from a resin composition in which a fluororesin and an aromatic polyester resin are added with a PPS resin as a main component.
In order to obtain a swash plate in which the sliding surface is not seized in this manner, the resin composition is more preferably 10 to 100 parts by weight of fluororesin and 20 to 100 aromatic polyester resins with respect to 100 parts by weight of PPS. It is the resin composition which mix | blended the weight part.

  If the blending amount of the fluororesin is less than a predetermined amount, sufficient sliding characteristics cannot be obtained as the fluororesin, and if it exceeds the predetermined amount, the adhesion strength with the metal substrate as the coating base is weakened.

  In addition, if the amount of the aromatic polyester resin is less than the predetermined amount, the heat resistance and wear resistance of the coating will be insufficient, and if it exceeds the predetermined amount, the adhesion strength with the metal substrate underlying the coating will be weakened. It is not preferable.

  In addition, in order to solve the problem of image sticking as described above, a swash plate compressor equipped with the above-described swash plate can be provided.

  According to the present invention, a sliding surface of a swash plate on which a shoe of a swash plate compressor slides is provided with a film made of a resin composition containing at least PPS and a fluororesin, and preferably added with an aromatic polyester resin. Since it is a swash plate or a swash plate type compressor using the swash plate, it becomes a swash plate which does not generate seizure even when the surface of the swash plate is in a dry lubrication state. There is an advantage to become.

Embodiments of a swash plate and a swash plate compressor according to the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1, a rotary shaft 2 that is driven in a housing 1 of a compressor that compresses a working fluid such as a refrigerant is provided, and is fixed integrally with the rotary shaft 2 to provide a disk-shaped swash plate 3. A pair of shoes 4 slidably contacted from both sides are provided on the periphery of the swash plate 3 so as to be held in the recess 5a of the piston 5, and the rotational fluid of the swash plate 3 is converted into the reciprocating motion of the piston 5 through the shoe 4 to obtain a working fluid. 2 is a swash plate 3 of a swash plate type compressor.

  The swash plate 3 can be stably rotated at a fixed position by holding both end surfaces of the boss 3a in the axial direction between the thrust needle roller bearings 8.

  As shown in FIG. 2, a film 11 made of a predetermined resin composition is formed on the shoe contact surface of the swash plate 3.

  The swash plate type compressor shown in FIG. 1 is a double swash plate type that compresses and expands working fluid on both axial sides of each piston 5 in a cylinder bore 7 formed at equal intervals in the circumferential direction of a cylindrical housing 1. The rotary shaft 2 that is rotationally driven at high speed by external power is supported by needle roller bearings 9 in the radial direction.

  A hemispherical shoe 4 is seated on a spherical seat 6 formed on the opposing surface in the axial direction of the recess 5 a of the piston 5. The shoe 4 may have a spherical shape or other shapes. When the rotational movement of the swash plate 3 is converted into the reciprocating movement of the piston 5, the shoe 4 is always in sliding contact with the swash plate in a stable posture. Smooth reciprocation is achieved.

  An example of the base material of the swash plate 3 is a metal material such as carbon steel S45C for mechanical structure, and the shoe 4 is formed of high carbon chromium bearing steel SUJ2. Further, a porous metal sprayed layer 10 made of a copper alloy is formed on both side surfaces of the swash plate 3 on which the shoe 4 slides, and a resin coating 11 is formed on the surface of such a metal substrate. Has been.

  There are two types of piston operation of such a swash plate compressor, a double swash plate type using a double-headed piston that can increase and decrease the pressure at both ends of the piston in the reciprocating direction, and a piston Although there is a swash plate type that can do it only at one end, any type may be used.

  In the above-described embodiment, the swash plate compressor to which the swash plate is mounted is illustrated as a double swash plate type, but it may be a swash plate type, and the shoe slides on one side of the swash plate. All known types of swash plate compressors may be used, such as those that move and those in which a swash plate is attached to a rotating shaft via a connecting member.

  The polyphenylene sulfide (PPS) resin, which is a component of the resin composition part used in the present invention, is a polymer composed of a repeating unit represented by the general formula represented by the following chemical formula 1 as a main structural unit.

  PPS is preferably a low molecular weight having an average particle size of 5 μm or less when used as a coating method on the swash plate surface, for example, when sprayed and uniformly dispersed in an organic solvent or water.

  Commercially available PPS satisfying such conditions is preferably Ryton V-1 manufactured by Philippe Sporium, Inc. or PPS oligomer described in US Pat. No. 4046749. In addition, when adopting a powder coating method such as fluidized dipping as a coating method, a linear PPS (for example, Kureha Chemical Industry Co., Ltd .: KSP) and a cross-linked PPS (for example, Topren Co., Ltd .: T-4) are also preferable. .

  In addition, the aromatic polyester resin in the present invention is a thermoplastic resin composed of a repeating unit represented by the following chemical formula 2 as a main structural unit, and examples of commercially available products include Econol manufactured by Sumitomo Chemical Co., Ltd.

  Such an aromatic polyester resin is uniformly dispersed in the composition, and the main structural unit is represented by the following chemical formula 3 with an average particle size of 5 μm or less so that the formed coating film surface is smooth. Econol E101F, which is a homopolymer of parahydroxybenzoic acid composed of repeating units, is particularly preferred. Such an aromatic polyester resin is blended in an amount of 20 to 100 parts by weight with respect to 100 parts by weight of PPS. This is because if the amount of the aromatic polyester resin is less than 20 parts by weight, sufficient heat resistance and wear resistance cannot be obtained for the formed coating film, and if it is more than 100 parts by weight, This is because the adhesion strength is reduced and the wear resistance is poor.

  As the fluororesin blended in the resin composition in the present invention, a known fluororesin can be adopted as long as it is made of a slidable fluoropolymer.

  A typical example of the fluororesin is polytetrafluoroethylene (PTFE) or tetrafluoroethylene-ethylene copolymer (ETFE), and it is preferable to use both of these in combination.

The fluorine-based polymer composed of PTFE or ETFE is preferably one having an average molecular weight of 50,000 or less, more preferably 5,000 to 30,000 in consideration of dispersibility during blending.
These average particle diameters are preferably 20 μm or less, and particularly preferably 5 to 10 μm. Commercially available fluoropolymers satisfying such conditions include PTFE, Asahi Glass Lubricant L169, Hoechst TF9502, Central Glass Co., Ltd., Cefral Lube, ETFE, Asahi Glass Co., Ltd. Aflon COP, and PFA as Mitsui DuPont Fluorochemical. For example, MP10 manufactured by the company.

  The blending ratio of the total amount of PTFE and ETFE is 10 to 100 parts by weight with respect to 100 parts by weight of PPS. If the total amount is less than 10 parts by weight, sufficient non-adhesiveness and sliding properties cannot be obtained. If the amount exceeds 100 parts by weight, the adhesion strength with the metal substrate is weakened and the wear resistance is poor. It is.

  In order to improve impact resistance and toughness, an elastomer material selected from organopolysiloxane elastomers or fluoroelastomers may be added.

  In this case, the organopolysiloxane elastomer may be exemplified by a wide range of organopolysiloxanes having a high degree of polymerization having a Si-O bond (siloxane bond) and rubber-like elasticity at room temperature. it can. Further, the molecular weight of the organopolysiloxane elastomer is usually desirably 50,000 or more, and since a high molecular weight as much as possible obtains good results, it is more desirably 70,000 or more, particularly desirably 10 to 25. Use about 10,000. Representative examples of the above conditions include polydimethyl silicone elastomer (hereinafter abbreviated as MQ) KE76 manufactured by Shin-Etsu Chemical Co., Ltd., methyl vinyl silicone elastomer (hereinafter abbreviated as VMQ) SH433 manufactured by Toray Silicone Co., Ltd., or Shin-Etsu Chemical Co., Ltd. Examples include TSE201, methylphenyl silicone elastomer (hereinafter abbreviated as PMQ) SE955U manufactured by Toray Silicone and fluorosilicone elastomer (hereinafter abbreviated as FVMQ) Silastic LS manufactured by Dow Corning.

  A fluoroelastomer is a polymer or copolymer of unit monomers containing an average of one or more fluorine atoms, and has a glass transition point of room temperature or lower and rubber-like elasticity at room temperature. It does not specifically limit and can illustrate a wide range. Examples of the polymerization method of the fluoroelastomer include bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, catalyst polymerization, ionizing radiation polymerization, and redox polymerization. Further, the molecular weight of the fluoroelastomer is usually desirably 50,000 or more, and since a high molecular weight as much as possible obtains good results, it is more desirably 70,000 or more, particularly desirably about 100,000 to 250,000. Use one. As representative examples corresponding to the above conditions, Aphras manufactured by Asahi Glass Co., which is a tetrafluoroethylene / propylene copolymer, DuPont which is a vinylidene fluoride / hexafluoropropylene copolymer, Viton manufactured by Showa Denko KK, vinylidene fluoride / Montefluos technoflon, a hexafluoropropylene / tetrafluoroethylene copolymer, Dow Corning silastic LS, a fluorosilicone elastomer, Firestone PNF, a phosphazene elastomer, Daikin, a perfluoroelastomer An example is Daiel Perflo manufactured by Kogyo Co., Ltd.

  The blending ratio of these elastomers is desirably 5 to 50 parts by weight with respect to 100 parts by weight of PPS. This is because if it is 5 parts by weight or less, the toughness and impact resistance properties that were the original purpose cannot be obtained, and if it exceeds 50 parts by weight, the adhesion strength with the metal substrate is weakened and the wear resistance is inferior. Because.

  In addition, you may mix | blend a well-known additive with a resin composition in the range which does not impair the objective of this invention. Appropriate blending ratios of the additives are different in specific gravity, so that if indicated by volume, 5 to 50 parts by volume is preferable with respect to 100 parts by volume of PPS, and 15 to 35 parts by volume is particularly preferable. Representative additives are listed below.

  Lubricant: graphite, molybdenum disulfide, reinforcing agent: glass fiber, carbon fiber, boron fiber, silicon carbide fiber, carbon whisker, asbestos, metal fiber, rock wool, etc., flame retardant: antimony oxide, magnesium carbonate, calcium carbonate, etc. Electrical property improvers: clay, mica, etc. Thermal conductivity improvers: iron, zinc, aluminum, copper and other metal compounds and other fillers: glass beads, glass spheres, alumina, talc, diatomaceous earth, hydrated alumina, shirasu In order to produce balloons, zinc oxide, titanium oxide, and other metal oxides, natural or synthetic compounds that are stable at 500 ° C or higher, and compositions containing the above materials, they can be dispersed as they are or dispersed in water or organic solvents. Grind with a ball or the like and mix homogeneously. The coating material thus obtained is applied by spray coating, fluid immersion, electrostatic coating or the like.

[Examples 1 to 3, Comparative Examples 1 and 2]
As a test piece for a swash plate base material of a swash plate type compressor, a ring-shaped test piece (outer diameter 33 mm, inner diameter 6 mm, length 6 mm) is made of carbon steel for mechanical structure S45C, and the surface is shown in Table 1. The paint was sprayed with a spray gun and baked at 370 ° C. for 45 minutes to form a smooth coating film.

  The obtained test piece was tested using a ball-on-disk type tester (3-ball-on tester) under the conditions of a load of 5 kgf, a rotational speed of 2000 rpm, a lubrication condition: dry, and a test time of 120 seconds. This result was evaluated in terms of the presence or absence of seizure or abnormal wear in four grades: excellent: 、, good: ◯, acceptable: △, impossible: x, and these results are shown in Table 1 together with symbols.

  As is apparent from the results in Table 1, Comparative Example 1 and Comparative Example 2 not containing a fluororesin were seized and abnormally worn, and could not be used as a swash plate.

  On the other hand, Examples 1 and 3 provided with a film made of a resin composition containing PPS resin and fluororesin (PTFE and ETFE) are good test results without seizure and abnormal wear. The blended Example 2 was a very good test result with no evidence of seizure or abnormal wear.

  From this test result, it was found that no seizure occurred in any of the examples, and the swash plate of the present invention could reliably prevent seizure from occurring in the sliding portion under dry lubrication conditions.

A longitudinal sectional view showing an embodiment of a swash plate compressor 1 is an enlarged longitudinal sectional view of the swash plate of FIG.

Explanation of symbols

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

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 compressor that compresses and expands the refrigerant by converting the movement into the reciprocating motion of the piston,
A swash plate for a swash plate compressor, wherein a coating film made of a resin composition containing a polyphenylene sulfide resin as a main component and a fluororesin is provided on a sliding surface of a swash plate on which the shoe slides.   The swash plate for a swash plate compressor according to claim 1, wherein the resin composition is a resin composition to which an aromatic polyester resin is added.   The swash plate compressor according to claim 2, wherein the resin composition is a resin composition in which 10 to 100 parts by weight of a fluororesin and 20 to 100 parts by weight of an aromatic polyester resin are blended with 100 parts by weight of a polyphenylene sulfide resin. Swashplate.   The swash plate of the swash plate type compressor according to any one of claims 1 to 3, wherein the base material of the swash plate is a metal base material.   The swash plate type compressor provided with the swash plate in any one of Claims 1-4.

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