Compressor

Abstract

To provide a compressor capable of reducing heat generation caused by sliding.SOLUTION: In a compressor that has in a closed container, a compression mechanism part for compressing a refrigerant, the refrigerant is an unsaturated refrigerant or a mixed refrigerant containing an unsaturated refrigerant, and the compression mechanism part contains chromium. The compression mechanism part includes a first member and a second member that slide relatively to each other. A blend layer containing chromium nitride and titanium nitride is formed on a surface of the first member. The titanium nitride in the blend layer is distributed so that a concentration of the titanium nitride regularly increases / decreases in the thickness direction of the blend layer, and carbide is precipitated on a surface of the second member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a compressor. [Background technology]

[0002] Refrigeration cycle devices such as air conditioners use compressors, such as refrigerant compressors, that have a compression mechanism that draws in and discharges a refrigerant, a working fluid. For example, heat is easily generated at sliding parts, such as the tip surfaces of compressor blades and the outer circumferential surfaces of rollers, which can cause the refrigerant to thermally decompose. Products resulting from the thermal decomposition of the refrigerant can lead to compressor failure. Patent Document 1 discloses that an antioxidant or the like is added to refrigerating machine oil in order to suppress thermal decomposition of the refrigerant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6011861 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 only considers refrigeration oil for suppressing thermal decomposition of the refrigerant, and it is also important to improve sliding parts to reduce heat generation due to sliding of the compressor.

[0005] A main problem to be solved by the present invention is to provide a compressor capable of reducing heat generation due to sliding. [Means for solving the problem]

[0006] A compressor according to an embodiment has a compression mechanism unit arranged in a sealed container to compress a refrigerant that is an unsaturated refrigerant or a mixed refrigerant containing an unsaturated refrigerant, the compression mechanism unit including a first member and a second member that contain chromium and slide relative to each other, a blend layer containing chromium nitride and titanium nitride is formed on a surface of the first member, the blend layer having a titanium nitride concentration that regularly increases and decreases in a thickness direction, and carbide is precipitated on a surface of the second member. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing a schematic configuration of a compressor according to an embodiment; [Figure 2] FIG. 2 is a cross-sectional view of the compressor shown in FIG. 1 along line II-II. [Figure 3] FIG. 2 is a perspective view of the cylinder, rollers, and blades of the compressor of FIG. 1. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing the tip surface side of the blade. [Figure 5] 1 is a graph showing the blend ratio of TiN in a blend layer, with the thickness of the blend layer on the horizontal axis and the TiN concentration on the vertical axis. [Figure 6] FIG. 10 is an enlarged cross-sectional view showing the tip surface side of another example of a blade. DETAILED DESCRIPTION OF THE INVENTION

[0008] The compressor according to the embodiment has a compression mechanism that compresses a refrigerant in a sealed container. The compression mechanism includes a first member and a second member that contain chromium and slide relative to each other. A blend layer containing chromium nitride and titanium nitride is formed on the surface of the first member, and carbide is precipitated on the surface of the second member. The titanium nitride in the blend layer is distributed such that the concentration of the titanium nitride increases and decreases regularly in the thickness direction of the blend layer.

[0009] The compressor according to the embodiment may be any compressor having these characteristics, and other than these characteristics, any known aspect may be adopted without limitation. The compressor according to the embodiment can be used in, for example, a refrigeration cycle device. One example is a refrigeration cycle device including the compressor according to the embodiment, a condenser serving as a heat radiator connected to the compressor, an expansion device connected to the condenser, and an evaporator serving as a heat absorber connected between the expansion device and the compressor.

[0010] The condenser dissipates heat from the high-temperature, high-pressure gas refrigerant sent from the compressor, converting it into a high-pressure liquid refrigerant. The expansion device reduces the pressure of the high-pressure liquid refrigerant sent from the condenser, converting it into a low-temperature, low-pressure liquid refrigerant. The evaporator vaporizes the low-temperature, low-pressure liquid refrigerant sent from the expansion device, converting it into a low-pressure gas refrigerant. In the evaporator, as the low-pressure liquid refrigerant vaporizes, it removes heat of vaporization from the surrounding area, cooling the surrounding area. The low-pressure gas refrigerant that passes through the evaporator is taken into the compressor. In this way, in a refrigeration cycle device, the refrigerant circulates while changing phases between gas refrigerant and liquid refrigerant.

[0011] (Compressor) FIG. 1 is a schematic diagram showing a schematic configuration of a compressor 1 according to an example of an embodiment. The compressor 1 is a so-called rotary compressor that takes in a gas refrigerant and compresses it to produce a high-temperature, high-pressure refrigerant. Note that the compressor of the embodiment is not limited to a rotary type, and may be a scroll type, reciprocating type, swash plate type, or other type of compressor.

[0012] The compressor 1 includes a compressor body 11 and an accumulator 12. The accumulator 12 is a so-called gas-liquid separator. The accumulator 12 is connected to the compressor body 11 through a suction pipe 21. The accumulator 12 is connected to the evaporator, and supplies only the gasified refrigerant to the compressor body 11 out of the refrigerant vaporized in the evaporator and the liquid refrigerant not vaporized in the evaporator.

[0013] The compressor body 11 includes a rotating shaft 31, an electric motor section 32, a compression mechanism section 33, and a sealed container 34 that houses the rotating shaft 31, the electric motor section 32, and the compression mechanism section 33. The sealed container 34 is formed in a cylindrical shape, and both ends in the direction of the axis O are closed. Refrigerating machine oil J is contained within the sealed container 34. A portion of the compression mechanism 33 is immersed in the refrigerating machine oil J.

[0014] The rotating shaft 31 is arranged coaxially along the axis O of the sealed container 34. In the following description, the direction along the axis O will be simply referred to as the axial direction, the direction perpendicular to the axial direction will be referred to as the radial direction, and the direction around the axis O will be referred to as the circumferential direction.

[0015] The electric motor unit 32 is disposed on a first axial side within the sealed container 34. The compression mechanism unit 33 is disposed on a second axial side within the sealed container 34. In the following description, the electric motor unit 32 side along the axial direction is referred to as the upper side, and the compression mechanism unit 33 side is referred to as the lower side.

[0016] The electric motor unit 32 is a so-called inner rotor type DC brushless motor. Specifically, the electric motor unit 32 includes a stator 35 and a rotor 36. The stator 35 is fixed to the inner wall surface of the sealed container 34 by shrink fitting or the like. The rotor 36 is fixed to the upper part of the rotating shaft 31 inside the stator 35 with a radial gap therebetween.

[0017] The compression mechanism 33 includes a cylindrical cylinder 41 through which the rotary shaft 31 passes, and a main bearing 42 and an auxiliary bearing 43 that close both axial end openings of the cylinder 41 and rotatably support the rotary shaft 31. The space formed by the cylinder 41, the main bearing 42, and the auxiliary bearing 43 constitutes a cylinder chamber 46.

[0018] An eccentric portion 51 that is radially eccentric with respect to the axis O is formed in a portion of the rotary shaft 31 that is positioned inside the cylinder chamber . A roller 53 is fitted onto the eccentric portion 51. The roller 53 is configured to be able to rotate eccentrically about the axis O as the rotary shaft 31 rotates, with an outer peripheral surface 53a in sliding contact with the inner peripheral surface 41a of the cylinder 41 via a film of refrigeration oil.

[0019] 2 and 3, a blade groove 54 recessed radially outward is formed in a portion of the circumferential direction of the cylinder 41. The blade groove 54 is formed over the entire axial direction (height direction) of the cylinder 41. The blade groove 54 communicates with the inside of the sealed container 34 at the radially outer end.

[0020] A blade 55 is provided in the blade groove 54. The blade 55 is configured to be slidable in the radial direction relative to the cylinder 41. As shown in FIG. 1, a back surface 55b, which is the radially outer end surface of the blade 55, is biased radially inward by a biasing means 57. As shown in FIGS. 2 and 3, a tip surface 55a, which is the radially inner end surface of the blade 55, abuts against an outer peripheral surface 53a of the roller 53 in the cylinder chamber 46. This allows the blade 55 to advance and retreat within the cylinder chamber 46 in accordance with the eccentric rotation of the roller 53. The roller 53 and the blade 55 divide the cylinder chamber 46 into a suction chamber 46a and a compression chamber 46b. Note that, in a plan view seen from the axial direction, the tip surface 55a of the blade 55 has an arc shape that convex radially inward.

[0021] Refrigerating machine oil J is interposed between the blade 55 and the inner surfaces 54a, 54b of the blade groove 54, between the blade 55 and the lower surface 42a of the main bearing 42, and between the blade 55 and the upper surface 43a of the sub-bearing 43.

[0022] A suction hole 56 is formed radially through the cylinder 41 in a portion located forward (to the left of the blade groove 54 in FIG. 2) in the direction of rotation of the roller 53 relative to the blade groove 54 (see the arrow in FIG. 2). The radially outer end of the suction hole 56 is connected to the suction pipe 21 (see FIG. 1). The radially inner end of the suction hole 56 opens into the suction chamber 46a of the cylinder chamber 46. A discharge groove 58 is formed in a portion of the cylinder 41 located forward of the blade groove 54 in the direction of rotation of the roller 53 (to the right of the blade groove 54 in FIG. 2). The discharge groove 58 is formed in a semicircular shape in a plan view seen from the axial direction. The discharge groove 58 opens at least on the top surface of the cylinder 41.

[0023] 1, the main bearing 42 closes the upper end opening of the cylinder 41. The main bearing 42 rotatably supports a portion of the rotating shaft 31 that is located above the cylinder 41. Specifically, the main bearing 42 includes a cylindrical portion 61 through which the rotating shaft 31 is inserted, and a flange portion 62 that protrudes radially outward from the lower end of the cylindrical portion 61.

[0024] 1 and 2, a discharge hole 64 (see FIG. 2) that axially penetrates the flange portion 62 is formed in a portion of the circumferential direction of the flange portion 62. The discharge hole 64 communicates with the inside of the cylinder chamber 46 through the discharge groove 58. The flange portion 62 is provided with a discharge valve mechanism (not shown) that opens and closes the discharge hole 64 in response to an increase in pressure in the cylinder chamber 46 (compression chamber 46b) to discharge the refrigerant out of the cylinder chamber 46.

[0025] The main bearing 42 is provided with a muffler 65 that covers the main bearing 42 from above. A communication hole 66 that communicates the inside and outside of the muffler 65 is formed in the muffler 65. The high-temperature, high-pressure gas refrigerant discharged through the discharge hole 64 is discharged into the sealed container 34 through the communication hole 66. The sub-bearing 43 closes the opening at the lower end of the cylinder 41. The sub-bearing 43 rotatably supports a portion of the rotating shaft 31 that is located below the cylinder 41. Specifically, the sub-bearing 43 includes a cylindrical portion 71 through which the rotating shaft 31 is inserted, and a flange portion 72 that protrudes radially outward from the upper end of the cylindrical portion 71.

[0026] In the compressor 2, when power is supplied to the stator 35 of the electric motor unit 32, the rotating shaft 31 rotates together with the rotor 36 around the axis O. Then, as the rotating shaft 31 rotates, the eccentric portion 51 and the roller 53 rotate eccentrically within the cylinder chamber 46. At this time, the outer peripheral surface 53a of the roller 53 is in sliding contact with the inner peripheral surface 41a of the cylinder 41 via a film of refrigeration oil. As a result, the gaseous refrigerant is taken into the cylinder chamber 46 through the suction pipe 21, and the gaseous refrigerant taken into the cylinder chamber 46 is compressed.

[0027] Specifically, gaseous refrigerant is drawn into suction chamber 46a of cylinder chamber 46 through suction hole 56, and the gaseous refrigerant previously drawn through suction hole 56 is compressed in compression chamber 46b. The compressed gaseous refrigerant is discharged to the outside of cylinder chamber 46 (into muffler 65) through discharge hole 64 of main bearing 42, and then discharged into sealed container 34 through communication hole 66 of muffler 65. The gaseous refrigerant discharged into sealed container 34 is sent to the condenser.

[0028] In the compression mechanism 33 of the compressor 1, the blade 55 and the roller 53 slide relative to each other with a tip end surface 55a of the blade 55 and an outer circumferential surface 53a of the roller 53 in contact with each other. The blade 55 and the cylinder 41 slide relative to each other with side surfaces 55c, 55d on both sides of the blade 55 and inner surfaces 54a, 54b of the blade groove 54 in contact with each other. The blade 55 and the main bearing 42 slide relative to each other with an upper end surface 55e of the blade 55 and a lower surface 42a of the main bearing 42 in contact with each other. The blade 55 and the sub-bearing 43 slide relative to each other with a lower end surface 55f of the blade 55 and an upper surface 43a of the sub-bearing 43 in contact with each other.

[0029] An example in which the first member is a blade 55 and the second member is a roller 53 will be described below. In a rotary compressor 1 such as the embodiment, the sliding conditions are severe and heat is most likely to occur in the sliding portion between the blade and the roller. Therefore, by using the features of the embodiment in which the first member is a blade 55 and the second member is a roller 53, the compressor 1 has particularly excellent long-term reliability. The first member may be the blade 55 and the second member may be the cylinder 41, the first member may be the blade 55 and the second member may be the main bearing 42, or the first member may be the blade 55 and the second member may be the sub-bearing 43. A combination of these may also be used.

[0030] The compression mechanism 33 contains chromium (Cr). In the compression mechanism 33, it is preferable that the base material of the first member contains Cr because it has excellent wear resistance. For example, the base material of the blade 55 can be made of a steel material containing Cr (for example, an SKH material such as SKH51). The base material of the roller 53 can be made of a special alloy cast iron (monichrome cast iron) in which Mo, Ni, Cr, etc. are added to FC250 gray cast iron. The cylinder 41, main bearing 42, and sub-bearing 43 can be made of gray cast iron such as FC250.

[0031] 4, a blend layer 81 containing chromium nitride (CrN) and titanium nitride (TiN) is formed on a surface 80a of a substrate 80 on the tip surface 55a side of a blade 55, which is a first member. The substrate 80 of the blade 55 contains Cr. Therefore, the substrate 80 and the blend layer 81 have excellent adhesion to each other.

[0032] Blend layer 81 is a layer containing CrN and TiN. By including TiN, which has high thermal conductivity, in blend layer 81 together with CrN, it is possible to efficiently dissipate heat generated by sliding between blade 55, which is the first member, and roller 53, which is the second member. As a result, the refrigerant is prevented from excessively increasing in temperature due to sliding heat generation, which would otherwise cause decomposition. Furthermore, the lattice constant of CrN is 0.41 nm, and the lattice constant of TiN is 0.42 nm, which are almost the same. Therefore, even though blend layer 81 contains both of these, distortion is small, and excellent peel resistance and adhesion can be obtained even as a thick film of 3 μm or more. Blend layer 81 is preferably a layer consisting of only two components, CrN and TiN, because this can easily prevent thermal decomposition of the refrigerant and a decrease in the lubricity of the refrigeration oil. However, blend layer 81 may contain components other than CrN and TiN as needed, provided that the effects of the present invention are not impaired.

[0033] The TiN in the blend layer 81 is distributed such that the concentration of TiN increases and decreases regularly in the thickness direction of the blend layer 81. The regular increase and decrease in the TiN concentration in the thickness direction of the blend layer 81 increases and decreases the efficiency of dissipating sliding heat compared to when the TiN concentration is constant, thereby enhancing the effect of suppressing decomposition of the refrigerant.

[0034] In the present invention, "the TiN concentration increases and decreases regularly in the thickness direction of the blend layer" means that when the TiN concentration in a cross-sectional region perpendicular to the thickness direction of the blend layer is measured while gradually changing the position in the thickness direction of the blend layer from the substrate side to the opposite side, the TiN concentration increases and decreases repeatedly, and the pattern of increase and decrease shows a constant pattern. A typical example is shown in Figure 5, where in a blend layer with a thickness of T (μm), the TiN concentration increases and decreases in a constant wave-like pattern from the position of zero thickness to the position of thickness T (μm).

[0035] The increase and decrease in TiN concentration in the thickness direction of the blend layer is considered "regular" if, in a graph with the horizontal axis representing the blend layer thickness and the vertical axis representing the TiN concentration, the difference between the upper and lower limits of the increasing and decreasing TiN concentration is within 10% and 10%, respectively, or if the average of the maximum and minimum peak concentrations of TiN concentration falls within the range of the average ± standard deviation × 3, as shown in Figure 5. Furthermore, the difference in the distance between adjacent peak tops in the thickness direction of the blend layer in the graph is considered "regular" if it is within 0.2 μm. In a graph in which the horizontal axis represents the thickness of the blend layer and the vertical axis represents the TiN concentration, the interval between peak tops is preferably 0.05 to 0.4 μm, and more preferably 0.2 μm.

[0036] The TiN concentration in a cross-sectional region perpendicular to the thickness direction of the blend layer 81 preferably varies within a range of 0 to 15 mass %, more preferably within a range of 0 to 10 mass %, and even more preferably within a range of 0 to 5.0 mass %, in the thickness direction of the blend layer 81. By varying the TiN concentration within this range, it becomes easy to obtain a blend layer 81 that combines efficiency in releasing sliding heat, adhesion to the substrate 80, and scratch resistance.

[0037] The number of repetitions of increasing and decreasing the TiN concentration in the thickness direction of the blend layer 81 is not particularly limited, and can be, for example, 5 to 9 times, 10 to 14 times, or 15 to 30 times.

[0038] The method for forming the blend layer 81 in which the TiN concentration increases and decreases regularly in the thickness direction is not particularly limited.

[0039] The thickness of the blend layer 81 is preferably 1.0 to 6.0 μm. If the thickness of the blend layer 81 is equal to or greater than the lower limit, abrasion resistance can be ensured even during long-term use. If the thickness of the blend layer 81 is equal to or less than the upper limit, peeling due to increased internal stress can be prevented. The lower limit of the thickness of the blend layer 81 is more preferably 3.0 μm or more. The upper limit of the thickness of the blend layer 81 is even more preferably 6.0 μm or less.

[0040] 6, a CrN layer 82 may be provided between the substrate 80 and the blend layer 81. By providing the CrN layer 82, the adhesion between the substrate 80 and the blend layer 81 can be improved. The CrN layer 82 is preferably a layer made of only CrN, as this provides excellent adhesion to the base material 80. The CrN layer 82 may contain components other than CrN as long as the effects of the embodiment are not impaired. The CrN layer 82 does not contain TiN.

[0041] The thickness of the chromium layer 82 is preferably from several nm to 1.0 μm or less. If the thickness of the chromium layer 82 is equal to or less than the upper limit value, the blend layer 81 is less likely to peel off. When the chrome layer 82 is provided, the total thickness of the chrome layer 82 and the blend layer 81 is preferably 0.5 to 7.0 μm. When the total thickness is equal to or greater than the lower limit, abrasion resistance can be ensured. When the total thickness is equal to or less than the upper limit, peeling due to increased internal stress can be prevented. The lower limit of the total thickness is more preferably 1.0 μm or more, and even more preferably 2.0 μm or more. The upper limit of the total thickness is more preferably 6.0 μm or less, and even more preferably 5.0 μm or less.

[0042] Carbide is precipitated on the outer peripheral surface 53a of the roller 53, which is the second member. Precipitation of hard carbide on the surface ensures wear resistance against the blend layer 81 of the blade 55, which is the first member.

[0043] (refrigerant) The refrigerant is not particularly limited, and examples thereof include unsaturated refrigerants and mixed refrigerants containing unsaturated refrigerants. Unsaturated refrigerants have poor chemical stability due to the double bond they contain, and tend to easily decompose due to sliding heat generation. In the embodiment, even when an unsaturated refrigerant or a mixed refrigerant containing an unsaturated refrigerant is used, refrigerant decomposition due to sliding heat generation can be sufficiently suppressed.

[0044] Furthermore, when carbon dioxide is used as the refrigerant, a high-temperature, high-pressure environment is created, which means that the viscosity of the refrigerating machine oil J in the compression mechanism 33 is likely to decrease with temperature, and its lubricity tends to decrease. However, in the embodiment, since the temperature increase caused by heat generated by sliding between the first and second members can be suppressed, even when carbon dioxide or a mixed refrigerant containing carbon dioxide is used as the refrigerant, the increase in wear caused by the decrease in viscosity of the refrigerating machine oil J can be suppressed, resulting in excellent reliability.

[0045] Furthermore, hydrocarbons or mixed refrigerants containing hydrocarbons have a lower refrigeration capacity per volume than conventional refrigerants such as HFC410A, so a higher refrigerant flow rate is required to ensure the desired refrigeration capacity. Increasing the number of compression cycles is an effective way to increase the refrigerant flow rate, but increasing the number of compression cycles increases the temperature of the compression mechanism, causing a decrease in the viscosity of the refrigeration oil J and making it more likely that the lubrication will be impaired. However, in the present embodiment, temperature increases due to heat generated by sliding between the first and second members can be suppressed. Therefore, even when a hydrocarbon or mixed refrigerant containing hydrocarbons is used as the refrigerant, increased wear due to a decrease in the viscosity of the refrigeration oil J can be suppressed, resulting in excellent reliability.

[0046] Specific examples of the refrigerant include propane, propylene, normal butane, 2-methylbutane, isobutane, refrigerant carbon dioxide gas (R744), HFO1225ye, HFO1233zd, HFO1233yd, HFO1234yf, HFO1234ze, HFO1234ye, and HFO1243zf. One refrigerant may be used alone, or two or more refrigerants may be used in combination.

[0047] (Refrigerating machine oil) The refrigerating machine oil is not particularly limited, and examples thereof include mineral oil, ester oil, polyol ester oil, polyvinyl ether oil, alkylene glycol oil, and polyalphaolefin oil. One type of refrigerating machine oil may be used alone, or two or more types may be used in combination.

[0048] A phosphorus-containing anti-friction agent may be added to the refrigerating machine oil. By blending the phosphorus-containing anti-friction agent into the refrigerating machine oil, a film made of a reaction product of the anti-friction agent is formed on the sliding surfaces of the first and second members that slide against each other. As a result, solid contact between the sliding members is prevented, and temperature increases due to sliding heat are further suppressed, making it possible to more efficiently suppress refrigerant decomposition. Specific examples of phosphorus-containing anti-friction agents include tricresyl phosphate (TCP), trithiophenyl phosphate, tri(nonylphenyl) phosphite, triphenyl phosphate, dialkyl hydrogen phosphite, etc. One type of anti-friction agent may be used alone, or two or more types may be used in combination.

[0049] When a phosphorus-containing anti-friction agent is blended into a refrigerating machine oil, the blending amount of the phosphorus-containing anti-friction agent is preferably 0.01 to 5 parts by mass per 100 parts by mass of refrigerant. The lower limit of the blending amount of the phosphorus-containing anti-friction agent is more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more. The upper limit of the blending amount of the phosphorus-containing anti-friction agent is more preferably 3 parts by mass or less, and even more preferably 1.5 parts by mass or less.

[0050] As described above, according to the embodiment, by forming a blend layer containing CrN and TiN on the surface of the first member, in which the TiN concentration regularly increases and decreases in the thickness direction, it is possible to reduce heat generation due to sliding contact between the first member and the second member. This makes it possible to suppress thermal decomposition of the refrigerant and a decrease in lubricating performance due to a decrease in the viscosity of the lubricating oil. Furthermore, the blend layer formed on the surface of the first member has excellent adhesion and is resistant to peeling, resulting in excellent wear resistance. These factors make it possible to realize a compressor with excellent reliability over a long period of time.

[0051] Although the embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Example]

[0052] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following descriptions.

[0053] [Example 1] In the compressor 1 illustrated in FIGS. 1 to 3, an experiment was conducted using the blade 55 as the first member and the roller 53 as the second member. SKH51 (hardness: HRC63) containing 4% by mass of Cr was used for the base material 80 of the blade 55. A 6.0 μm-thick blend layer 81 containing CrN and TiN was formed on the surface 80a of the base material 80 on the tip surface 55a side of the blade 55 by PVD treatment. In the blend layer 81, the TiN concentration was repeatedly increased and decreased in the thickness direction within a range of 0 to 5% by mass in a wave-like pattern 15 times. The material of the roller 53, which is the second member, was monochromatic cast iron (HRC50) containing 0.8% by mass of Cr. The amount of carbides precipitated on the outer peripheral surface 53a of the roller 53 was 4% by mass.

[0054] An evaluation test was carried out using the compressor 1 equipped with this blade 55 and roller 53. The refrigerant used was R744 (carbon dioxide), and the refrigeration oil was a blend of polyalkylene glycol (PAG) and tricresyl phosphate. The operating conditions during the test were a refrigeration oil temperature of over 130°C (approximately 130-150°C), a suction pressure of 3.0 MPa, and a discharge pressure of 12.0 MPa. The device was operated for 2000 hours under the above configuration and conditions, and the wear of the blades after the test was evaluated according to the following criteria. <Evaluation criteria> "○": Blade wear is less than 1 μm. "X": The amount of blade wear is greater than 1 μm.

[0055] [Comparative Example 1] A compressor having the same configuration as in Example 1 was manufactured, except that a 2 μm thick diamond-like carbon (DLC) layer was formed instead of the blend layer 81 on the surface 80a of the substrate 80 on the tip end surface 55a side of the blade 55, and was evaluated in the same manner as in Example 1.

[0056] [Reference example 1] A compressor having the same configuration as Comparative Example 1 was manufactured and evaluated in the same manner as in Example 1, except that the set temperature of the refrigerating machine oil in the evaluation test was changed to less than 130°C (approximately 110 to 130°C).

[0057] The evaluation results of Example 1, Comparative Example 1 and Reference Example 1 are shown in Table 1.

[0058] [Table 1]

[0059] As shown in Table 1, the compressor of Comparative Example 1, in which a DLC layer was formed on the surface of the blades, experienced greater blade wear than Reference Example 1, in which the oil temperature was set to less than 130° C. In contrast, the compressor of Example 1, in which a blend layer was formed on the surface of the blades, experienced reduced wear of the blades and rollers. [Explanation of symbols]

[0060] 1 Compressor 31 Rotation axis 34 Airtight containers 41 cylinders 42 Main bearing 43 Sub bearing 46 Cylinder chamber 53 Laura 53a Outer surface 54 Blade Groove 55 Blades 55a Tip surface 80 Base material 81 Blend Layer 82 CrN layer

Claims

1. A compressor having a compression mechanism that compresses a refrigerant in a sealed container, The refrigerant is an unsaturated refrigerant or a mixed refrigerant containing an unsaturated refrigerant, the compression mechanism portion contains chromium, the compression mechanism includes a first member and a second member that slide relative to each other; a blend layer containing chromium nitride and titanium nitride is formed on a surface of the first member; the titanium nitride in the blend layer is distributed such that the concentration of the titanium nitride increases and decreases regularly in the thickness direction of the blend layer; A compressor, wherein carbides are precipitated on the surface of the second member.

2. A compressor having a compression mechanism that compresses a refrigerant in a sealed container, the refrigerant is carbon dioxide or a mixed refrigerant containing carbon dioxide, the compression mechanism portion contains chromium, the compression mechanism includes a first member and a second member that slide relative to each other; a blend layer containing chromium nitride and titanium nitride is formed on a surface of the first member; the titanium nitride in the blend layer is distributed such that the concentration of the titanium nitride increases and decreases regularly in the thickness direction of the blend layer; A compressor, wherein carbides are precipitated on the surface of the second member.

3. A compressor having a compression mechanism that compresses a refrigerant in a sealed container, the refrigerant is a hydrocarbon or a mixed refrigerant containing a hydrocarbon, the compression mechanism portion contains chromium, the compression mechanism includes a first member and a second member that slide relative to each other; a blend layer containing chromium nitride and titanium nitride is formed on a surface of the first member; the titanium nitride in the blend layer is distributed such that the concentration of the titanium nitride increases and decreases regularly in the thickness direction of the blend layer; A compressor, wherein carbides are precipitated on the surface of the second member.

4. The compressor according to any one of claims 1 to 3, wherein the concentration of titanium nitride in a cross-sectional region perpendicular to the thickness direction of the blend layer increases or decreases in the range of 0 to 5.0 mass% in the thickness direction of the blend layer.

5. The compressor according to any one of claims 1 to 3, wherein the sealed container contains refrigerating machine oil blended with a phosphorus-containing anti-wear agent.

6. The compressor according to any one of claims 1 to 3, which is a rotary compressor having a blade as the first member and a roller as the second member.

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