JP5374294B2 - Refrigerant compressor and refrigeration cycle apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deformation of a base material of a sliding member employed in a refrigerant compressor and improve adhesion of a coating formed on a surface of the base material. <P>SOLUTION: In a sliding member 15b of a compression mechanism part, a surface-hardened metallic material is formed as a base material 24. A coating formed by successively laminating a first layer 25 formed of a chromium single layer, a second layer 26 formed of an alloy layer of chromium and tungsten carbide, a third layer 27 formed of an amorphous carbon layer containing metal containing at least one of tungsten and tungsten carbide and a fourth layer 28 formed of an amorphous carbon layer not containing metal and containing carbon and hydrogen, is formed on a surface of the base material 24. The second layer 26 keeps a chromium content higher at the first layer 25 side rather than the third layer 27 side and a tungsten carbide content higher at the third layer 27 side rather than the first layer 25 side. The third layer 27 keeps a tungsten or tungsten carbide content higher at the second layer 26 side rather than the fourth layer 28 side. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a refrigerant compressor and a refrigeration cycle apparatus, and more particularly to a refrigerant compressor and a refrigeration cycle apparatus provided with a sliding member having a film excellent in wear resistance and adhesion.

  A sliding member for compressing the refrigerant is used in the compression mechanism portion that compresses the refrigerant in the refrigerant compressor, and as a refrigerant compressor with improved wear resistance of the sliding member, the following patent document 1 is known.

  The sliding member (for example, vane) of the refrigerant compressor described in Patent Document 1 forms a nitride layer on the surface of a base material (base material) to cure the base material, and an intermediate layer and a single layer thereon. Alternatively, two amorphous carbon layers are formed. When two amorphous carbon layers are formed, the lower layer side (base material side) is a hydrogen-containing amorphous carbon layer, and the upper layer side is a metal-containing amorphous carbon layer.

JP 2007-32360 A

  The sliding member described in Patent Document 1 is formed by forming a nitride layer on the surface of the base material and curing the base material, so that deformation of the base material at the time of high load action is suppressed, and the base material and the intermediate layer Excellent adhesion. However, when the amorphous carbon layer is made into two layers between the intermediate layer and the amorphous carbon layer, there is a problem in adhesion between the two amorphous carbon layers. Peeling or cracking may occur between the intermediate layer and the amorphous carbon layer or when there are two amorphous carbon layers.

  The present invention has been made to solve such problems, and its purpose is to deform the base material of the sliding member when a high load is applied to the sliding member used in the refrigerant compressor. It is intended to suppress and improve the adhesion of the film formed on the surface of the base material of the sliding member.

A first feature according to an embodiment of the present invention is that, in the refrigerant compressor including a compression mechanism unit that compresses the refrigerant used during the refrigeration cycle, at least one of the sliding members of the compression mechanism unit is surface-hardened. A treated metal material is formed as a base material, and a first layer made of a single layer of chromium, a second layer made of an alloy layer of chromium and tungsten carbide, tungsten, A film is formed by sequentially laminating a third layer made of a metal-containing amorphous carbon layer containing at least one of tungsten carbide and a fourth layer made of an amorphous carbon layer containing no metal and containing carbon and hydrogen. The second layer has a chromium content higher on the first layer side than on the third layer side, and a tungsten carbide content on the third layer side than on the first layer side. ~ side Is formed so as to be higher, the third layer is formed to the second layer side content than the fourth layer side of the tungsten or tungsten carbide is increased, and the first layer, That is , the total thickness dimension of the second layer and the third layer is made smaller than the thickness dimension of the fourth layer .

  A second feature according to the embodiment of the present invention is that the refrigeration cycle apparatus includes the refrigerant compressor, the condenser, the expansion device, and the evaporator according to the first feature.

  According to the present invention, when a high load is applied to the sliding member used in the refrigerant compressor, the deformation of the base material of the sliding member can be suppressed, and the base material of the sliding member can be suppressed. The adhesion of the film formed on the surface can be improved.

It is a mimetic diagram showing the refrigerating cycle device of a 1st embodiment of the present invention. It is a vertical front view which shows the internal structure of a refrigerant compressor. It is a perspective view which shows the cylinder, roller, and vane which comprise a compression mechanism part. It is sectional drawing which shows the front-end | tip part of a vane. 6 is a graph showing the results of relative comparison of film strength between Example 1 and Comparative Example 1. It is explanatory drawing which shows the measurement result of the surface hardness of a base material, and the adhesiveness of a film in the 2nd Embodiment of this invention. It is sectional drawing which shows the front-end | tip part of the vane of the 3rd Embodiment of this invention. 6 is a graph showing measurement results of film strengths of Example 3, Comparative Example 2, and Comparative Example 1. It is a graph which shows the hardness from the surface in the base material of Example 3 and Comparative Example 2. FIG. It is sectional drawing which shows the surface part of the bearing of the 4th Embodiment of this invention. 6 is a graph showing measurement results of film strengths of Example 4, Comparative Example 3, and Comparative Example 1. It is a graph which shows the measurement result of the film | membrane intensity | strength of Example 5, the comparative example 4, and the comparative example 1 in the 5th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a refrigeration cycle apparatus 1 according to a first embodiment of the present invention.

  The refrigeration cycle apparatus 1 includes a hermetic rotary type refrigerant compressor 2, a four-way valve 3, an outdoor heat exchanger 4 that functions as a condenser during cooling operation and functions as an evaporator during heating operation, and an expansion device 5 The indoor heat exchanger 6 that functions as an evaporator during the cooling operation and also functions as a condenser during the heating operation and the accumulator 7 are formed to communicate in a cycle.

  In the refrigeration cycle apparatus 1, during cooling operation, the refrigerant discharged from the refrigerant compressor 2 is supplied to the outdoor heat exchanger (condenser) 4 through the four-way valve 3, as indicated by solid arrows, It is condensed by exchanging heat with the outside air. The condensed refrigerant flows out of the outdoor heat exchanger 4, flows into the indoor heat exchanger (evaporator) 6 through the expansion device 5, and evaporates by exchanging heat with indoor air in the indoor heat exchanger 6. And cool the room air. The refrigerant flowing out of the indoor heat exchanger 6 is sucked into the refrigerant compressor 2 through the four-way valve 3 and the accumulator 7.

  On the other hand, during the heating operation, the refrigerant discharged from the refrigerant compressor 2 is supplied to the indoor heat exchanger (condenser) 6 through the four-way valve 3 as indicated by the dashed arrows, where indoor air and heat are supplied. It exchanges and is condensed and heats indoor air. The condensed refrigerant flows out of the indoor heat exchanger 6 and flows into the outdoor heat exchanger (evaporator) 4 through the expansion device 5, and exchanges heat with outdoor air in the outdoor heat exchanger 4 to evaporate. To do. The evaporated refrigerant flows out of the outdoor heat exchanger 4 and is sucked into the refrigerant compressor 2 through the four-way valve 3 and the accumulator 7.

  Thereafter, the refrigerant flows sequentially in the same manner, and the operation of the refrigeration cycle apparatus 1 is continued. As the refrigerant, HFC refrigerant, HC (hydrocarbon) refrigerant, carbon dioxide refrigerant or the like is used.

  The refrigerant compressor 2 is a two-cylinder type as shown in FIG. 2, and includes a sealed case 2a. In the sealed case 2a, an electric motor unit 8 and a rotary compression mechanism unit 9 which is a compression mechanism unit are accommodated. The electric motor unit 8 and the rotary compression mechanism unit 9 are connected via a rotary shaft 10 having eccentric portions 10a and 10b. It is connected.

  The electric motor unit 8 includes a rotor 8a and a stator 8b, and may be any of a brushless DC synchronous motor driven by an inverter, an AC motor, a motor driven by a commercial power source, and the like.

  Refrigerating machine oil 11 for lubricating the rotary compression mechanism 9 is stored at the bottom of the sealed case 2a. As the refrigerating machine oil 11, POE (polyol ester), PVE (polyvinyl ether), PAG (polyalkylene glycol), or the like is used.

  The rotary compression mechanism unit 9 includes a first compression mechanism unit 9a and a second compression mechanism unit 9b. The first compression mechanism unit 9a includes a cylinder 13a that forms a cylinder chamber 12a, and includes a second compression mechanism 9a. The mechanism portion 9b includes a cylinder 13b that forms a cylinder chamber 12b. A roller 14b and a vane 15b as a sliding member are accommodated in the cylinder 13b, and a roller 14a and a vane 15a (not shown) as a sliding member are accommodated in the cylinder 13a. 2 shows a part of the first compression mechanism 9a and the second compression mechanism 9b in different sections so that the state of the vane 15b and the connection state of the suction pipe 23 can be understood.

  The roller 14b is fitted in the eccentric portion 10b of the rotating shaft 10, and rotates in the cylinder chamber 12b as the rotating shaft 10 rotates. The roller 14 a is fitted to the eccentric portion 10 a of the rotating shaft 10 and rotates in the cylinder chamber 12 a as the rotating shaft 10 rotates.

  As shown in FIG. 3, the vane 15b is slidably fitted in a groove 16b formed in the cylinder 13b. A spring (not shown) that biases the vane 15b is housed in the groove 16b so that the tip of the vane 15b slides on the outer peripheral surface of the roller 14b. The vane 15a is slidably fitted in a groove (not shown) formed in the cylinder 13a, and the vane 15a is attached in the groove so that the tip of the vane 15a is in sliding contact with the outer peripheral surface of the roller 14b. An energizing spring (not shown) is accommodated.

  Both ends of the cylinder 13a of the first compression mechanism 9a are covered with the main bearing 17 and the partition plate 18, and a cylinder chamber 12a is formed inside. Both ends of the cylinder 13b of the second compression mechanism 9b are covered with the auxiliary bearing 19 and the partition plate 18, and a cylinder chamber 12b is formed inside. The main bearing 17 is provided with a discharge hole 20a that communicates between the cylinder chamber 12a and the inside of the sealed case 2a, and a discharge valve 21a that opens and closes the discharge hole 20a. The sub-bearing 19 is provided with a discharge hole 20b that communicates between the cylinder chamber 12b and the inside of the sealed case 2a, and a discharge valve 21b that opens and closes the discharge hole 20b.

  A discharge pipe 22 that discharges the compressed refrigerant in the sealed case 2a toward the four-way valve 3 is connected to the upper surface of the sealed case 2a. A suction pipe 23 that guides the refrigerant that has passed through the accumulator 7 into the cylinder chambers 12a and 12b is connected to the lower side of the side surface of the sealed case 2a.

  FIG. 3 is a perspective view showing the cylinder 13b, the roller 14b, and the vane 15b constituting the second compression mechanism 9b. The first compression mechanism 9a has the same configuration as the second compression mechanism 9b, and the first compression mechanism 9a includes a cylinder 13a, a roller 14a, a vane 15a, and the like.

  FIG. 4 is a cross-sectional view showing a part of the tip side of the vane 15b. The vane 15b uses a base material 24 formed by cold forging a chromium-molybdenum steel that is a metal material. The base material 24 is subjected to a surface hardening process by carburizing and quenching, and the surface hardness is set to 650 in terms of Vickers hardness. . This surface hardening treatment does not mean that only the surface of the base material 24 is hardened, but means that at least the surface of the base material 24 is hardened, and includes the case where the whole base material 24 is hardened.

  Furthermore, on the surface of the base material 24 subjected to the surface hardening treatment, a first layer 25 made of a single layer of chromium (Cr) and a second layer made of an alloy layer of chromium and tungsten carbide (WC). 26, a third layer 27 made of an amorphous carbon layer containing tungsten (W), and a film 29 in which a fourth layer 28 made of an amorphous carbon layer containing no metal and containing carbon and hydrogen is sequentially laminated. Is formed. The third layer 27 may be an amorphous carbon layer containing tungsten carbide instead of tungsten, or an amorphous carbon layer containing both tungsten and tungsten carbide.

  The second layer 26 has a higher chromium content on the first layer 25 side than the third layer 27, and a tungsten carbide content on the third layer 27 side than the first layer 25 side. It is formed by inclining the contained components so as to be higher.

  The third layer 27 is formed by inclining the contained components so that the tungsten content is higher on the second layer 26 side than on the fourth layer 28 side.

  The thicknesses of the layers 25 to 28 are 0.1 μm for the first layer 25, 0.2 μm for the second layer 26, 0.5 μm for the third layer 27, and 2.2 μm for the fourth layer 28. In addition, the overall heat dimension of the film 29 composed of each of the layers 25 to 28 is 3 μm.

  FIG. 5 is a graph showing the relative evaluation of the results of measuring the strength against breakage, peeling, damage, etc., between the film 29 formed on the vane 15b and the film formed on the vane described in Patent Document 1. is there. In this measurement, the vane 15b (Example 1) or the vane (Comparative Example 1) of Patent Document 1 is attached to the rotary compression mechanism unit 9 of the refrigerant compressor 2, and the liquid refrigerant is forcedly intermittently supplied to the rotary compression mechanism unit 9. And repeatedly sucking the vane 15b into the roller 14b. From this measurement result, it was found that the vane 15b of the first embodiment has a film strength that is about 20% higher than that of the vane of Patent Document 1.

  In such a configuration, by subjecting the base material 24 of the vanes 15a and 15b formed of a metal material to surface hardening treatment by carburizing and quenching, elastic deformation of the base material 24 at the time of high load action can be suppressed. For this reason, the deformation | transformation of the membrane | film | coat 29 at the time of a high load effect | action can be suppressed, and the adhesiveness between the base material 24 and the membrane | film | coat 29 and each layer 25-28 in the membrane | film | coat 29 can be improved.

  Regarding the four layers 25 to 28 constituting the film 29, the first layer 25 is a single layer of chromium, the second layer 26 is an alloy layer of chromium and tungsten carbide, and the third layer 27 is tungsten and A metal-containing amorphous carbon layer containing at least one of tungsten carbide is used, and the fourth layer 28 is an amorphous carbon layer containing no metal and containing carbon and hydrogen. Further, the second layer 26 is formed such that the chromium content is higher on the first layer 25 side than the third layer 27, and the tungsten carbide content is third on the first layer 25 side. The components are inclined so as to be higher on the layer 27 side. In addition, the third layer 27 is formed by tilting the contained components so that the tungsten content is higher on the second layer 26 side than on the fourth layer 28 side.

  Therefore, between the first layer 25 and the second layer 26, between the second layer 26 and the third layer 27, and between the third layer 27 and the fourth layer 28. The difference in hardness is reduced, whereby the adhesion between these layers 25 to 28 can be improved, and the occurrence of cracks and the like inside the coating 29 can be suppressed.

  In addition, since the fourth layer 28 located on the outermost side of the coating 29 is an amorphous carbon layer that does not contain metal and contains carbon and hydrogen, higher hardness can be achieved than the amorphous carbon layer that contains metal. The wear resistance of the vane 15b can be improved.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. The basic structure of the vane of the second embodiment is the same as that of the vanes 15a and 15b described in the first embodiment, and portions related to the structure of the vane will be described with reference to FIG.

  FIG. 6 is an explanatory diagram showing the results of measuring the adhesion of the film 29 in various cases with various surface hardnesses of the base material 24 of the vane. Specifically, by subjecting the base material 24 to surface hardening treatment, the surface hardness of the base material 24 was set to less than 70, less than 70 and less than 80, and 80 or more in terms of Rockwell hardness HRA. Further, the surface hardness of the substrate 24 was set to less than 25, 25 or more, less than 60, or 60 or more in terms of Rockwell hardness HRC. Furthermore, the surface hardness of the base material 24 was less than 400, 400 or more, less than 800, or 800 or more in terms of Vickers hardness.

  This measurement is similar to the measurement described in the first embodiment, in which a vane is attached to the rotary compression mechanism unit 9 of the refrigerant compressor 2 and liquid refrigerant is forcibly and repeatedly sucked into the rotary compression mechanism unit 9 repeatedly. The vane violently collided with the roller 14b.

  In addition, a vane in which the film described in Patent Document 1 (a film of a known example) is formed on the surface of the base material 24 with various surface hardnesses is manufactured, and the same measurement is performed on the prototype. I did it.

  According to the measurement result, in the vane of the second embodiment, the surface hardness of the base material 24 is 70 or more in Rockwell hardness HRA, 25 or more in Rockwell hardness HRC, or Vickers hardness. It was found that sufficient adhesion can be obtained between the base material 24 and the film 29 and between the layers 26 to 28 in the film 29 by setting it to 400 or more. Furthermore, the surface hardness of the base material 24 is 80 or more in Rockwell hardness HRA, 60 or more in Rockwell hardness HRC, or 800 or more in Vickers hardness, thereby providing even more sufficient adhesion. Was found to be obtained.

  On the other hand, when the film described in Patent Document 1 is formed on the surface of the substrate 24, the Rockwell hardness HRA is 70 or more and less than 80, and the Rockwell hardness HRC is 25 or more and less than 60. It has been found that sufficient adhesion cannot be obtained when the Vickers hardness is 400 or more and less than 800.

  In such a configuration, when the surface hardness of the base material 24 is 70 or more in Rockwell hardness HRA, 25 or more in Rockwell hardness HRC, or 400 or more in Vickers hardness, a high load is achieved. It is possible to suppress the deformation of the base material 24 and to suppress the deformation of the film 29 at the time of action. For this reason, the adhesiveness between the base material 24 and the membrane | film | coat 29 and between each layers 26-28 in the membrane | film | coat 29 can be improved, and a durable vane can be obtained.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS.

  The basic structure of the vane 15A of the third embodiment is the same as the vane 15b shown in FIG. 4, and the vane 15A uses a base material 24A formed of stainless steel (SUS440C) as a metal material. The surface of the substrate 24A is hardened by radical nitriding to form a diffusion layer 30 in which nitrogen is diffused inside the substrate 24A, and the surface hardness of the substrate 24A is set to 900 in terms of Vickers hardness. A nitrogen compound layer (so-called white layer) is not formed.

  Furthermore, a film 29 composed of four layers 25 to 28 is formed on the surface of the base material 24A after the surface hardening treatment.

  FIG. 8 shows a vane 15A of the third embodiment (Example 3), a vane in which a film 29 is formed on a base material obtained by radical nitriding carbon steel (Comparative Example 2), and a vane described in Patent Document 1. It is a graph which shows the measurement result which carried out relative comparison of the film strength with (comparative example 1). This measurement was performed in the same manner as the measurement described in the first embodiment.

  From this measurement result, it was found that the film strength of the vane 15A was higher than those of Comparative Example 2 and Comparative Example 1.

  FIG. 9 is a graph showing the hardness from the surface of the base material 24A of the vane 15A of Example 3 and the base material of the vane of Comparative Example 2. In Example 3, the effect of surface hardening by radical nitriding is great, and deformation of the base material 24A is suppressed.

  In such a configuration, stainless steel has high hardness obtained by radical nitriding, and deformation during high load action is suppressed. For this reason, the deformation | transformation of the membrane | film | coat 29 formed in the surface of 24 A of base materials is also suppressed, and the adhesiveness between the base materials 24 and the membrane | film | coat 29 and each layer 26-28 in the membrane | film | coat 29 can be improved.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIGS. In this embodiment, a bearing 31 that is a sliding member is subjected to a surface hardening treatment and a film 29 is formed on the surface thereof. The bearing 31 corresponds to the main bearing 17 and the auxiliary bearing 19 described with reference to FIG. 2 of the first embodiment.

  The bearing 31 uses iron, copper, and a carbon-based sintered alloy as the base material 24B. The base material 24B is subjected to a surface hardening process by a steam treatment to form a triiron tetroxide 32 on the surface of the base material 24B. The holes 33 formed in the surface of the base material 24B are filled during sintering. In addition, the surface hardness of the base material 24B is set to 450 by the Vickers hardness by forming the iron tetroxide 32.

  Further, a film 29 composed of four layers 25 to 28 is formed on the surface of the base material 24 </ b> B after the surface hardening treatment is performed.

  FIG. 11 shows a bearing 31 according to a fourth embodiment (Example 4), a bearing having a coating 29 formed on the surface of a base material 24B on which iron trioxide 32 is not formed (Comparative Example 3), and a surface hardening treatment. It is a graph which shows the measurement result which compared the film | membrane intensity | strength with the bearing (comparative example 1) which formed the film | membrane described in patent document 1 on the base material which performed. This measurement was performed in the same manner as the measurement described in the first embodiment.

  From this measurement result, it was found that the film strength of the bearing 31 was higher than those of Comparative Example 4 and Comparative Example 1.

(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a rotating shaft (corresponding to the rotating shaft 10 in FIG. 2), which is a sliding member, is formed using spheroidal graphite cast iron (FCD600) as a base material, and the surface is subjected to surface hardening treatment by hard chrome plating. The surface hardness is set to 700 in terms of Vickers hardness.

  Further, a film 29 composed of four layers 25 to 28 is formed on the surface of the base material after the surface hardening treatment is performed.

  FIG. 12 shows a rotating shaft (Example 5) of the fifth embodiment, a rotating shaft (Comparative Example 4) in which a film 29 is formed on a base material made of spheroidal graphite cast iron without applying hard chrome plating, It is a graph which shows the measurement result which carried out the relative comparison of the film | membrane intensity | strength with the rotating shaft (comparative example 1) which formed the film | membrane described in patent document 1 on the base material which carried out the hardening process. This measurement was performed in the same manner as the measurement described in the first embodiment.

  According to this measurement result, it was found that the film strength of the rotating shaft of Example 5 was higher than that of Comparative Example 4 and Comparative Example 1.

  In this embodiment, a rotating shaft using spheroidal graphite cast iron as a base material is described as an example. However, as a base material of the rotating shaft, flake graphite cast iron, molybdenum, nickel, chromium, etc. are used. Added special flake graphite cast iron may be used.

  Further, the surface hardening treatment may be performed by heat treatment such as austempering treatment or deep cooling treatment instead of hard chrome plating.

2 Refrigerant compressor, 4 outdoor heat exchanger (condenser, evaporator), 5 expansion device, 6 indoor heat exchanger (evaporator, condenser), 9 rotary compression mechanism (compression mechanism), 15a, 15b vane (Sliding member), 15A vane (sliding member), 24 base material, 24A base material, 24B base material, 25 first layer, 26 second layer, 27 third layer, 28 fourth layer, 29 Coating, 31 Bearing (sliding member)

Claims (4)

In a refrigerant compressor provided with a compression mechanism for compressing refrigerant used during the refrigeration cycle
At least one of the sliding members of the compression mechanism is formed using a surface-hardened metal material as a base material,
A metal-containing amorphous material containing at least one of tungsten and tungsten carbide, a first layer made of a single layer of chromium, a second layer made of an alloy layer of chromium and tungsten carbide, on the surface of the base material A film is formed by sequentially laminating a third layer made of a carbon layer and a fourth layer made of an amorphous carbon layer containing no metal and containing carbon and hydrogen,
The second layer has a chromium content higher on the first layer side than the third layer side, and a tungsten carbide content on the third layer side than the first layer side. Formed to be high,
The third layer is formed so that the content of tungsten or tungsten carbide is higher on the second layer side than on the fourth layer side ,
A refrigerant compressor , wherein a total thickness dimension of the first layer, the second layer, and the third layer is made smaller than a thickness dimension of the fourth layer . A refrigerant compressor, wherein the thickness dimension is gradually reduced from the fourth layer toward the first layer . The refrigerant according to claim 1, wherein the surface hardness of the base material is 70 or more in Rockwell hardness HRA, 25 or more in Rockwell hardness HRC, or 400 or more in Vickers hardness. Compressor. A refrigeration cycle apparatus comprising: the refrigerant compressor according to any one of claims 1 to 3, a condenser, an expansion device, and an evaporator.

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