JP4898162B2 - Hermetic compressor and refrigeration cycle apparatus - Google Patents

Description

  The present invention relates to a hermetic compressor and a refrigeration cycle apparatus, and more particularly to a hermetic compressor having an improved sliding member and a refrigeration cycle apparatus that constitutes a refrigeration cycle using the hermetic compressor.

The refrigeration cycle is also used in refrigeration apparatuses such as air conditioners, refrigerators, and refrigeration showcases for cooling and heating the interior of a room, and more recently in heat pump water heaters. These refrigeration cycles incorporate a hermetic compressor that circulates HFC refrigerant, other HC refrigerant, and other natural refrigerants such as CO ₂ .

  For example, a general rotary-type hermetic compressor provided in an air conditioner includes an electric motor unit and a compression mechanism unit connected to the electric motor unit via a rotating shaft in a hermetic case. The compression mechanism portion accommodates an eccentric roller in a cylinder chamber provided in the cylinder, and is pressed and urged by a compression spring so that the tip edge of the blade is elastically contacted with the peripheral surface of the eccentric roller. Therefore, the cylinder chamber is divided into a suction chamber and a compression chamber along the rotation direction of the eccentric roller by the blade.

  The hermetic compressor is required to be operated at a higher speed, higher load (high pressure, high compression ratio, high temperature), and longer life. For this reason, various sliding members such as cylinders and blades are subjected to various surface treatments such as nitriding treatment, nitronitriding treatment, hard film coating such as CrN on the surface of the sliding metal (base material) and wear resistance. The improvement of the property is aimed at.

  However, it is difficult to improve the wear resistance sufficiently by various nitriding treatments. Further, although the hard film coating has good wear resistance, there is a problem that the sliding counterpart member is worn.

  For this reason, in Patent Document 1, a base layer made of compounds having different compositions composed of carbon, nitrogen, and a transition metal is formed on a base material by sputtering or CVD, and a diamond-like carbon film is formed on the base layer. Describes a sliding member used in a compressor or the like in which a solid lubricating film is formed so that the hardness from the uppermost layer toward the base material is sequentially reduced.

  In Patent Document 2, a wear-resistant surface treatment layer (gas nitride layer, Cr plating film or ion plating film such as chromium nitride or titanium nitride) is formed on the surface of the base material, and Si, Ti, A piston ring in which a hard film made of diamond-like carbon in which carbides of one or more elements selected from the group of W, Cr, Mo, Nb, and V are dispersed is described.

  However, in Patent Document 1, since a base layer made of a predetermined compound is formed on the surface of the base material and a diamond-like carbon film is formed thereon, when a high load such as sliding is applied to the sliding member The base layer is susceptible to elastic deformation, and there is a risk of peeling at the interface between the base material and the base layer.

Further, the nitride layer described in Patent Document 2 generally has a nitrogen compound layer (a nitrogen compound layer in which a base material and nitrogen are reacted in a stoichiometric ratio) formed on the surface. For this reason, when a high load such as sliding is applied to the piston ring, the nitrogen compound layer as the surface treatment layer is easily subjected to elastic deformation, and as in Patent Document 1, peeling occurs at the interface between the base material and the nitrogen compound layer. May occur.
JP2001-107860 Japanese Patent Laid-Open No. 11-172413

  The present invention provides a hermetic compression having a sliding member that improves adhesion to a base material and adhesion between layers, and can effectively exhibit the characteristics of the uppermost hydrogen-containing amorphous carbon layer or metal-containing amorphous carbon layer. And a refrigeration cycle apparatus including the hermetic compressor.

According to the present invention, in a hermetic compressor provided in a refrigeration cycle, compressing and circulating a refrigerant, and having a sliding member,
The sliding member is formed of a base material made of a steel material, a nitrogen amount nitride layer formed by diffusing nitrogen on the surface of the base material, and generating no nitrogen compound of the steel material and nitrogen, and the nitride layer Formed of at least a sliding surface with a mating member and made of a single layer or a plurality of layers selected from metals selected from tungsten, chromium, silicon, titanium, molybdenum and zirconium, and oxides, nitrides and carbides of these metals. An intermediate layer, a hydrogen-containing amorphous carbon layer formed on the intermediate layer , and at least selected from tungsten, chromium, silicon, titanium, molybdenum, zirconium carbides and oxides formed on the hydrogen-containing amorphous carbon layer. hermetic compressor provided is characterized by having a structure including a metal-containing amorphous carbon layer containing one compound That.

  Furthermore, according to the present invention, there is provided a refrigeration cycle apparatus comprising the hermetic compressor, a condenser, a decompression device, and an evaporator.

  According to the present invention, adhesion to a base material and adhesion between layers are improved, and characteristics of the uppermost hydrogen-containing amorphous carbon layer or metal-containing amorphous carbon layer (wear resistance, smoothness, conformability, mating member) It is possible to provide a hermetic compressor that has a sliding member that can effectively express (low wear resistance), can be used in various refrigerants and various refrigeration cycles, and guarantees stable operation over a long period of time.

  In addition, a refrigeration cycle apparatus including the hermetic compressor and capable of stable refrigeration cycle operation for a long period of time can be provided.

  Hereinafter, a hermetic compressor and a refrigeration cycle apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional structure of a hermetic compressor A according to the embodiment and a refrigeration cycle configuration diagram of a refrigeration apparatus including the hermetic compressor A.

  First, the hermetic compressor A will be described. In the figure, reference numeral 1 denotes a hermetic case, and a compression mechanism unit 3 and a motor unit 4 to be described later are integrally connected to the inside of the hermetic case 1 via a rotating shaft 2. The electric compressor main body 5 to be used is accommodated. The rotating shaft 2 is provided along the central axis of the sealed case 1, the compression mechanism unit 3 is disposed on the lower side of the sealed case 1, and the electric motor unit 4 is disposed on the upper side of the sealed case 1. .

  The compression mechanism section 3 is a two-cylinder type having two sets of cylinders 7A and 7B with an intermediate partition plate 6 interposed therebetween. The electric motor unit 4 is a so-called outer rotor type electric motor unit including a stator 8 and an umbrella-shaped rotor 9 provided on the outer diameter side of the stator 8.

  Further, the compression mechanism section 3 will be described in detail. The first cylinder 7A is located on the upper side, and the second cylinder 7B is located on the lower side via the intermediate partition plate 6. A main bearing 10 is attached to the upper surface of the first cylinder 7A. The lower opening surface of the first cylinder 7A and the upper opening surface of the second cylinder 7B are closed by the intermediate partition plate 6, and the auxiliary bearing 11 is attached to the lower surface of the second cylinder 7B.

  Therefore, a first cylinder chamber 12 surrounded by the main bearing 10 and the intermediate partition plate 6 is formed in the first cylinder 7A, and the intermediate partition plate 6 and the sub main bearing 11 are formed in the second cylinder 7B. An enclosed second cylinder chamber 13 is formed.

  Each of the first and second cylinder chambers 12 and 13 accommodates an eccentric part a integrally provided on the rotary shaft 2, and a roller b is rotatably fitted in the eccentric part a. Each eccentric part a is eccentric so that the center of gravity is located in a symmetrical direction with respect to each other via the central axis of the rotating shaft 2 and at the same size position.

  In each of the cylinder chambers 12 and 13, the eccentric part a and the roller b rotate eccentrically as the rotary shaft 2 rotates. In any position of the eccentric rotation of the roller b, a part of the circumferential surface along the axial direction always comes into linear contact with the circumferential surfaces of the cylinder chambers 12 and 13.

  A blade storage chamber (schematically shown only on the second cylinder chamber side) 14 is provided at the side of each cylinder 7A, 7B, and a spring 15 and a blade 16 are stored therein. The spring 15 always presses elastically so that the tip of the blade 16 contacts the peripheral surface of the roller b. As a result, the blade 16 separates the cylinder chambers 12 and 13.

  FIG. 2 shows the second cylinder 7B.

  A refrigerant pipe P communicating with the condenser B is provided at the upper end of the sealed case 1. Two refrigerant tubes Pa and Pb communicating with the gas-liquid separator E pass through the side of the sealed case 1 and communicate with the compression mechanism 3. Between the condenser B and the gas-liquid separator E, the expansion device C and the evaporator D are communicated with each other through the refrigerant pipe P. The hermetic compressor A, the condenser B, the condenser C, the evaporator D, and the gas-liquid separator E constitute a refrigeration cycle circuit R of the refrigeration apparatus.

  In the above-described hermetic compressor A, when a drive signal is input to the motor unit 4, the rotor 9 is driven to rotate. The rotating shaft 2 connected integrally with the rotor 9 rotates, and the eccentric portion a and the roller b of the rotating shaft 2 rotate eccentrically in the first cylinder chamber 12 and the second cylinder chamber 13.

  Accordingly, low-pressure refrigerant gas is sucked into the first and second cylinder chambers 12 and 13 through the refrigerant pipes Pa and Pb, and is compressed to become high-pressure gas. The high-pressure gas compressed in the cylinder chambers 12 and 13 is discharged into the sealed case 1 and is filled.

  The high-pressure gas filling the sealed case 1 is discharged from the sealed case 1 to the refrigerant pipe P, led to the condenser B connected to the outside of the compressor A, condensed, and further led to the expansion device C to expand under reduced pressure. Further, a refrigeration cycle action is performed in which the gas is led to the evaporator D and evaporated. Then, it is guided to the gas-liquid separator E to be gas-liquid separated, and again sucked into the compressor A to circulate through the above-mentioned path.

  The blade 16 as the sliding member has a structure shown in FIGS. 3A to 3C described below.

The blade 16 shown in FIG. 3A includes a base material 21 made of a steel material. On the surface of the base material 21, a nitride layer 22 having a nitrogen amount smaller than the stoichiometric ratio of the nitrogen compound is formed by diffusion of nitrogen. A sliding surface of the nitride layer 22 with the mating member (roller, cylinder), for example, the front end surface, is simply selected from tungsten, chromium, silicon, titanium, molybdenum, zirconium and oxides, nitrides and carbides of these metals. An intermediate layer 23 composed of a layer or a plurality of layers is formed. A hydrogen-containing amorphous carbon layer 24 is formed on the intermediate layer 23.

  The blade 16 shown in FIG. 3B has at least one selected from carbides and oxides of tungsten, chromium, silicon, titanium, molybdenum, zirconium on the hydrogen-containing amorphous carbon layer 24 shown in FIG. It has a structure in which a metal-containing amorphous carbon layer 25 containing one compound is further formed.

  The blade 16 shown in FIG. 3C is selected from carbides and oxides of tungsten, chromium, silicon, titanium, molybdenum, zirconium instead of the hydrogen-containing amorphous carbon layer 24 shown in FIG. The metal-containing amorphous carbon layer 25 containing at least one compound has a structure formed on the intermediate layer 23.

  Examples of the steel material used for the base material 21 include high-speed tool steel such as SKH51, stainless steel such as SUS440C, gray cast iron such as FC200 and FC250, and spheroidal graphite cast iron such as FCD600. . In particular, it is preferable to use a steel material such as high-speed tool steel or stainless steel containing 3% by weight or more of chromium as the base material of the blade. The upper limit of the chromium content is preferably 20% by weight.

  The nitride layer 22 can be formed by, for example, two methods described below.

(1) The base material surface is nitrided by a nitriding method such as gas nitriding (including gas oxynitriding and gas soft nitriding), sulfur nitriding, plasma nitriding, liquid nitriding, or the like. At this time, the base material generated on the base material surface and the nitrogen compound layer of nitrogen are removed by mechanical polishing or the like so that the nitrogen compound layer does not exist, that is, a nitride layer having a nitrogen amount smaller than the stoichiometric ratio of the nitrogen compound is formed. Form.

  (2) For example, a mixed gas of ammonia and hydrogen is turned into plasma by glow discharge, active radicals (eg, NH radicals) are generated, and nitrogen is diffused and permeated into the base material surface to form a nitride layer without a nitrogen compound layer. To do.

  The thickness of the nitride layer 22 is preferably 30 μm or more from the viewpoint of increasing the hardness of the surface of the base material 21.

  The intermediate layer 23 is preferably composed of a plurality of layers. For example, the intermediate layer is preferably composed of a plurality of layers such as tungsten carbide (WC) / chromium (Cr) in the upper layer / lower layer.

  The hydrogen-containing amorphous carbon layer 24 preferably has a micro Vickers hardness (Hv) of 1800-2500. The hydrogen-containing amorphous carbon layer 24 preferably has a thickness of 1.0 to 3.0 μm.

  The metal-containing amorphous carbon layer 25 preferably has a micro Vickers hardness (Hv) of 1000 to 1500.

  When the metal-containing amorphous carbon layer 25 is formed on the hydrogen-containing amorphous carbon layer 24 as shown in FIG. 3B, the metal-containing amorphous carbon layer 25 has a thickness of 0.3 to 2.5 μm. It is preferable to have a thickness. In this case, the thickness ratio of the hydrogen-containing amorphous carbon layer 24 / metal-containing amorphous carbon layer 25 is preferably 5-1.

  When the metal-containing amorphous carbon layer 25 is formed on the intermediate layer 23 as shown in FIG. 3C, the metal-containing amorphous carbon layer 25 has a thickness of 1.0 to 5.0 μm. Is preferred.

  In the blade 13 described above, the intermediate layer 23, the hydrogen-containing amorphous carbon layer 24, and the like are formed only on the tip surface of the base material 21 having the nitride layer 22. However, these layers may be formed on the entire surface.

As described above, the blade 16 shown in FIG. 3A which is a sliding member according to the embodiment is formed on the base material 21 made of a steel material and the surface of the base material 21, and is based on the stoichiometric ratio of the nitrogen compound. A sliding surface between the nitride layer 22 having a small amount of nitrogen and at least a mating member (cylinder) of the nitride layer 22, for example, tungsten, chromium, silicon, titanium, molybdenum, zirconium and oxides of these metals formed on the tip surface, The intermediate layer 23 includes a single layer or a plurality of layers selected from nitrides and carbides, and a hydrogen-containing amorphous carbon layer 24 formed in the intermediate layer 23.

In the blade 16 having such a configuration, since the nitride layer 22 having a nitrogen amount smaller than the stoichiometric ratio of the nitrogen compound is formed on the surface of the base material 21, the base material 21, the intermediate layer 23, and the hydrogen-containing amorphous carbon layer 24 are formed. The hardness difference between them can be reduced. As a result, the adhesion between them can be improved. In particular, by forming a nitride layer 22 having substantially no nitrogen compound layer on the surface thereof on the surface of the base material 21, when a high load is applied when the tip of the blade 16 is slid on the cylinder inner surface, the base material 21 The hardness deformation and the absence of the nitrogen compound layer on the surface can reduce the elastic deformation of the surface of the base material 21. As a result, the adhesion of the intermediate layer 23 to the surface of the base material 1 is improved, and the intermediate layer 23 can be prevented from peeling off from the surface of the base material 1.

  Further, the uppermost hydrogen-containing amorphous carbon layer 24 has improved wear resistance due to high hardness, improved smoothness due to the amorphous structure, improved conformability due to a small friction coefficient, and further applied to a counterpart member (for example, a cylinder). Can exhibit low wear.

  Therefore, the blade 16 shown in FIG. 3A, which is a sliding member according to the embodiment, has an uppermost hydrogen-containing amorphous carbon layer due to high adhesion between the base material 21, the intermediate layer 23, and the hydrogen-containing amorphous carbon layer 24. 24 excellent properties (abrasion resistance, smoothness, conformability, low wear against the mating member) can be effectively expressed. As a result, the hermetic compressor having the blade 16 can be used in various refrigerants and various refrigeration cycles, and can guarantee stable operation over a long period of time.

Also, the blade 16 shown in FIG. 3C, which is a sliding member according to the embodiment, is formed on a base material 21 made of a steel material and the surface of the base material 21, and nitrogen is determined from the stoichiometric ratio of the nitrogen compound. A small amount of nitride layer 22 and at least a mating member (cylinder) sliding surface of nitride layer 22 such as tungsten, chromium, silicon, titanium, molybdenum, zirconium and oxides of these metals, nitrided An intermediate layer 23 composed of a single layer or a plurality of layers selected from an oxide and a carbide, and at least one compound selected from carbides and oxides of tungsten, chromium, silicon, titanium, molybdenum, zirconium formed in the intermediate layer 23 The metal-containing amorphous carbon layer 25 is included.

  Such a blade can reduce the difference in hardness between the base material 21, the intermediate layer 23, and the metal-containing amorphous carbon layer 25 and improve the adhesion between them, as shown in FIG. can do.

  In addition, the metal-containing amorphous carbon layer 25 as the uppermost layer exhibits wear resistance, improved smoothness due to the amorphous structure, improved conformability due to a small friction coefficient, and low wear to the mating member (for example, cylinder). it can. In particular, the amorphous carbon layer 25 has an action of relieving internal stress in the layer by containing a metal. For this reason, it is possible to prevent the metal-containing amorphous carbon layer 25 from being peeled off from the intermediate layer even when subjected to local stress during the initial operation of the compressor in which the parts are not familiar with each other.

  Therefore, the blade 16 shown in FIG. 3C, which is the sliding member according to the embodiment, has the uppermost metal-containing amorphous carbon layer due to high adhesion between the base material 21, the intermediate layer 23, and the metal-containing amorphous carbon layer 25. 25 excellent properties (abrasion resistance, smoothness, conformability, low wear against the mating member) can be effectively expressed, and in addition, initial conformability can be improved. As a result, the hermetic compressor having the blade 16 can be used in various refrigerants and various refrigeration cycles, and can guarantee stable operation over a long period from the beginning.

Further, the blade 16 shown in FIG. 3B, which is a sliding member according to the embodiment, is formed on the base material 21 made of a steel material and the surface of the base material 21, and is based on the stoichiometric ratio of the nitrogen compound. A sliding surface between the nitride layer 22 having a small amount of nitrogen and at least a mating member (cylinder) of the nitride layer 22, for example, tungsten, chromium, silicon, titanium, molybdenum, zirconium and oxides of these metals formed on the tip surface, An intermediate layer 23 composed of a single layer or a plurality of layers selected from nitride and carbide, a hydrogen-containing amorphous carbon layer 24 formed on the intermediate layer 23, and the metal-containing amorphous formed on the hydrogen-containing amorphous carbon layer 24 The structure includes the carbon layer 25.

  The hermetic compressor having the blade 16 having such a configuration can be used in various refrigerants and various refrigeration cycles, and can guarantee more stable operation from the initial stage over a long period of time.

  Hereinafter, embodiments of the present invention will be described in detail.

Example 1
First, a SUS440C steel material was processed to produce a vane-shaped base material with one end protruding in a tapered shape. Subsequently, the base material is placed in a chamber, a mixed gas of ammonia and hydrogen is introduced into the chamber, and plasma is generated by glow discharge to generate active radicals (for example, NH radicals). A nitride layer having a thickness of 50 μm without a nitrogen compound layer was formed by diffusion and permeation treatment on the surface. Subsequently, a Cr layer having a thickness of 0.1 μm and a WC layer having a thickness of 0.2 μm were formed in this order on the front end surface of the base material having a nitride layer on the surface by a sputtering method to form an intermediate layer. The WC layer was provided with a concentration gradient so that the carbon concentration increased from the Cr layer side to the surface. Next, a vane was manufactured by forming a hydrogen-containing amorphous carbon layer having a thickness of 3 μm on the intermediate layer by sputtering.

(Comparative Example 1)
A vane was manufactured by performing a gas nitriding process on the surface of the base material similar to that in Example 1 to form a nitride layer having a thickness of 60 μm having a nitrogen compound layer on the surface.

(Comparative Example 2)
A vane was manufactured by subjecting the surface of the base material similar to that of Example 1 to a nitronitriding treatment using a mixed gas of H ₂ S and NH ₃ to form a nitronitriding layer having a thickness of 60 μm.

(Comparative Example 3)
A vane was manufactured by forming a hard film made of CrN having a thickness of 5 μm on the surface of the base material similar to that in Example 1 by sputtering.

  A vane-on-disk abrasion test was performed on the obtained vanes of Example 1 and Comparative Examples 1 to 3. That is, a shaft 32 is attached to the center of a disc 31 made of Mo—Ni—Cr cast iron shown in FIG. The disk 31 was rotated about the shaft 32 at a speed of 716 rpm while applying a 1 kN load to the vane 33 with the taper tip of 33 being in contact. The amount of wear of the vane after rotating for 1 hour and the amount of wear of the disk as the mating member were measured. FIG. 5 shows the vane wear amount, and FIG. 6 shows the disc wear amount.

  As is apparent from FIG. 5, the vane of Example 1 has an extremely small amount of wear compared to the vanes of Comparative Examples 1 to 3. Further, as is apparent from FIG. 6, the amount of wear of the disk when the vane of Example 1 is slid on the disk which is the mating member is the same as that of the comparative examples 1 to 3. It can be seen that it is reduced compared to that of the case. Therefore, it was confirmed that the vane of Example 1 has excellent wear resistance and low wear against the mating member.

(Example 2)
A vane was manufactured by further forming a tungsten-containing amorphous carbon layer having a thickness of 1.5 μm on the hydrogen-containing amorphous carbon layer of Example 1.

(Example 3)
A vane similar to that in Example 1 was manufactured except that a tungsten-containing amorphous carbon layer having a thickness of 3 μm was formed as an intermediate layer instead of the uppermost hydrogen-containing amorphous carbon layer.

  The vane of Example 2 and 3 obtained was subjected to the same vane-on-disk wear test as Example 1. As a result, the wear amount of the vane and the disk of the mating member was the same as in Example 1, and it was confirmed that the vane and the mating member had excellent wear resistance and low wear to the mating member.

The cross-sectional structure of the hermetic compressor which concerns on embodiment of this invention, and the refrigerating cycle block diagram of the freezing apparatus provided with this hermetic compressor A. The principal part perspective view of the hermetic compressor incorporated in FIG. Sectional drawing which shows the braid | blade integrated in the hermetic compressor of the freezing apparatus of FIG. The perspective view which shows a vane on disk abrasion tester. The figure which shows the abrasion loss of the vane of Example 1 and Comparative Examples 1-3. The figure which shows the abrasion loss of a disk when the vane of Example 1 and Comparative Examples 1-3 is made to slide on a disk.

Explanation of symbols

  A ... Sealed compressor, B ... Condenser, C ... Condenser, D ... Evaporator, E ... Gas-liquid separator, R ... Refrigeration cycle circuit, 1 ... Sealed case, 3 ... Compression mechanism part, 4 ... Electric motor part 7A, 7B ... cylinder, 12, 13 ... cylinder chamber, a ... eccentric part, b ... roller, 16 ... blade, 21 ... base material, 22 ... nitride layer, 23 ... intermediate layer, 24 ... hydrogen-containing amorphous carbon layer, 25 ... Metal-containing amorphous carbon layer, 31 ... Disc, 33 ... Vane.

Claims (2)

In a hermetic compressor provided in a refrigeration cycle, compressing and circulating a refrigerant, and having a sliding member,
The sliding member is formed of a base material made of a steel material, a nitrogen amount nitride layer formed by diffusing nitrogen on the surface of the base material, and generating no nitrogen compound of the steel material and nitrogen, and the nitride layer Formed of at least a sliding surface with a mating member and made of a single layer or a plurality of layers selected from metals selected from tungsten, chromium, silicon, titanium, molybdenum and zirconium, and oxides, nitrides and carbides of these metals. An intermediate layer, a hydrogen-containing amorphous carbon layer formed on the intermediate layer , and at least selected from tungsten, chromium, silicon, titanium, molybdenum, zirconium carbides and oxides formed on the hydrogen-containing amorphous carbon layer. A hermetic compressor having a configuration including a metal-containing amorphous carbon layer containing one compound . A refrigeration cycle apparatus comprising the hermetic compressor according to claim 1 , a condenser, a decompression device, and an evaporator.

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