JP2017053339A - Refrigerant compressor and freezer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration compressor excellent in reliability without deteriorating abrasion resistance, even with low viscosity of lubricant and downsizing of a slide part.SOLUTION: At least one slide member constituting a compression element comprises a base material 150 made of a ferrous material and an oxide film 151 formed on the surface of the base material. The oxide film comprises, in order from an outermost surface of a slide surface, an outermost portion 151a whose main component is made of diiron trioxide (FeO), an intermediate portion 151b whose main component comprises triiron tetraoxide (FeO) and contains silicate (Si oxide), and an internal portion 151c whose main component is triiron tetraoxide (FeO) and contains silicate (Si oxide) and a silicon (Si) solid solution part. Consequently, abnormal abrasion due to agglutination or the like can be prevented, and reliability can be improved.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a refrigerant compressor used for a refrigerator, an air conditioner, and the like, and a refrigeration apparatus using the same.

  In recent years, development of highly efficient compressors that reduce the use of fossil fuels has been promoted from the viewpoint of global environmental protection.

  The high-efficiency refrigerant compressor forms a phosphate coating on the sliding surface to prevent wear of sliding portions such as pistons and crankshafts, and this phosphate coating forms a machine finish. Measures such as eliminating irregularities on the processed surface and improving the initial familiarity between the sliding members are taken (for example, see Patent Document 1).

  FIG. 11 shows a cross section of a conventional hermetic electric refrigerant compressor described in Patent Document 1. As shown in FIG. 11, an airtight container 1 serving as an outer casing of a refrigerant compressor stores lubricating oil 2 at the bottom, and an electric element 5 including a stator 3 and a rotor 4, and a reciprocating type driven by the same. The compression element 6 is accommodated.

  And the said compression element 6 is comprised by the crankshaft 7, the cylinder block 11, piston 15, etc., The structure is demonstrated below.

  The crankshaft 7 includes a main shaft portion 8 into which the rotor 4 is press-fitted and fixed, and an eccentric shaft 9 formed eccentric to the main shaft portion 8, and includes an oil supply pump 10.

  The cylinder block 11 forms a compression chamber 13 composed of a substantially cylindrical bore 12 and has a bearing portion 14 that supports the main shaft portion 8.

  The piston 15 loosely fitted to the bore 12 is connected to the eccentric shaft 9 via a piston pin 16 by a connecting rod 17 as a connecting means. The end face of the bore 12 is sealed with a valve plate 18.

  A head 19 is fixed to the opposite side of the bore 12 of the valve plate 18 to form a high pressure chamber. The suction tube 20 is fixed to the sealed container 1 and connected to the low pressure side (not shown) of the refrigeration cycle, and guides a refrigerant gas (not shown) into the sealed container 1. The suction muffler 21 is sandwiched between the valve plate 18 and the head 19.

  The main shaft portion 8 and the bearing portion 14 of the crankshaft 7, the piston 15 and the bore 12, the piston pin 16 and the connecting rod 17, and the eccentric shaft 9 and the connecting rod 17 of the crankshaft 7 form a sliding portion.

  Among the sliding members that make up the sliding part, in the combination of ferrous materials, an insoluble phosphate coating consisting of porous crystals is formed on the surface of either sliding part as described above. doing.

  Next, the operation of the above configuration will be described.

  Electric power supplied from a commercial power source (not shown) is supplied to the electric element 5 to rotate the rotor 4 of the electric element 5. The rotor 4 rotates the crankshaft 7 and drives the piston 15 via the connecting rod 17 and the piston pin 16 of the connecting means by the eccentric movement of the eccentric shaft 9. The piston 15 reciprocates in the bore 12, sucks the refrigerant gas introduced into the sealed container 1 through the suction tube 20 from the suction muffler 21, and continuously compresses it in the compression chamber 13.

  The lubricating oil 2 is supplied to each sliding portion from the oil supply pump 10 as the crankshaft 7 rotates, lubricates each sliding portion, and controls the seal between the piston 15 and the bore 12.

  Here, the main shaft portion 8 and the bearing portion 14 of the crankshaft 7 are rotating, the rotation speed is 0 m / s while the compressor is stopped, and the rotation starts from the metal contact state when starting. In this refrigerant compressor, since the phosphate coating is formed on the main shaft portion 8 of the crankshaft 7 and the phosphate coating has initial conformability, It is possible to prevent abnormal wear due to metal contact during startup.

Japanese Patent Laid-Open No. 7-238885

  However, in recent years, in order to increase the efficiency of the compressor, the lubricating oil 2 having a lower viscosity is used, or the sliding length between the sliding portions is designed to be shorter. The phosphate coating is worn or worn at an early stage, making it difficult to maintain the conforming effect and possibly reducing the wear resistance.

  Further, in the refrigerant compressor, the load applied to the main shaft portion 8 of the crankshaft 7 greatly varies during one rotation of the crankshaft 7, and the change between the crankshaft 7 and the bearing portion 14 accompanies this load variation. Thus, the refrigerant gas dissolved in the lubricating oil 2 may be vaporized and foamed, thereby increasing the frequency with which the oil film is cut and contacts the metal. As a result, the phosphate coating formed on the main shaft portion 8 of the crankshaft 7 is worn early, the friction coefficient increases, and the heat generated in the sliding portion is increased accordingly, which may cause abnormal wear such as adhesion. was there. Moreover, since the same phenomenon is caused between the piston 15 and the bore 12, there is a similar problem.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a highly reliable and highly efficient compressor by improving the wear resistance of the sliding member.

A refrigerant compressor according to the present invention stores lubricating oil in a hermetically sealed container, and houses an electric element and a compression element that is driven by the electric element to compress refrigerant, and includes at least one slide that constitutes the compression element. The moving member is an iron-based material, and on the sliding surface of the iron-based material, the most occupied component is ferric trioxide (Fe ₂ O ₃ ) and the most occupied component is triiron tetroxide (Fe ₃ O ₄ ) containing silicate (Si oxide), and the most occupying component is triiron tetroxide (Fe ₃ O ₄ ), and the silicate (Si oxide) and silicon (Si) solid solution part. It is the structure which gave the oxide film which consists of a part to contain.

  This improves the wear resistance of the sliding member and improves the adhesion between the base material and the oxide film, so the viscosity of the lubricating oil is lower and the sliding length between the sliding parts is shorter. it can. As a result, sliding loss can be reduced, and reliability and performance are improved.

  With the above configuration, the refrigerant compressor of the present invention can be designed with a lower viscosity of the lubricating oil and a shorter sliding length between the sliding portions, so that sliding loss can be reduced and reliability is high. A highly efficient refrigerant compressor can be provided.

Sectional drawing of the refrigerant compressor in Embodiment 1 of this invention. TEM (Transmission Electron Microscope) image showing an example of the result of TEM (Transmission Electron Microscope) observation of the oxide film applied to the sliding member of the refrigerant compressor in Embodiment 1, and the result of EDS analysis Elemental map showing an example Explanatory drawing which shows the abrasion amount of the disk after the ring on disk type abrasion test of the oxide film in the same embodiment Explanatory drawing which shows the wear amount of the ring after the ring-on-disk type abrasion test of the oxide film in the same embodiment EELS map and analysis diagram showing an example of the result of EELS analysis of the oxide film in the same embodiment EELS map and analysis diagram showing an example of the result of EELS analysis of the outermost part of the oxide film in the same embodiment Analysis drawing showing an example of the result of EELS analysis of the middle part of the oxide film in the same embodiment Analysis diagram showing an example of the result of EELS analysis of the inner part of the oxide film in the same embodiment TEM (transmission electron microscope) image showing an example of the result of TEM (transmission electron microscope) observation after the reliability test of the oxide film in the same embodiment Schematic diagram of a refrigeration apparatus in Embodiment 2 of the present invention Sectional view of a conventional hermetic electric refrigerant compressor

According to a first aspect of the present invention, at least one sliding member that stores lubricating oil in an airtight container, houses an electric element and a compression element that is driven by the electric element and compresses refrigerant, and constitutes the compression element. Is an iron-based material, and on the sliding surface of the iron-based material, the most occupied component is ferric trioxide (Fe ₂ O ₃ ) and the most occupied component is triiron tetroxide (Fe ₃ O _4). ) Containing silicate (Si oxide), and the most occupying component is triiron tetroxide (Fe ₃ O ₄ ) and containing silicate (Si oxide) and silicon (Si) solid solution parts It is set as the structure which gave the oxide film which consists of these.

  As a result, the wear resistance of the sliding member is improved and the adhesion of the oxide film is improved, so that abnormal wear due to adhesion or the like can be prevented, the viscosity of the lubricating oil is lower, and the sliding between the sliding portions is reduced. Since the dynamic length can be designed to be shorter, sliding loss can be reduced, and reliability and performance are improved.

According to a second invention, in the first invention, the oxide film has, in order from the outermost surface of the sliding surface, the outermost part in which the most occupied component is composed of ferric trioxide (Fe ₂ O ₃ ), and the most The occupying component is triiron tetroxide (Fe ₃ O ₄ ) and an intermediate portion composed of a portion containing silicate (Si oxide), and the most occupying component is triiron tetroxide (Fe ₃ O ₄ ). (Si oxide) and the inner part which consists of a part containing a silicon (Si) solid solution part are set as the structure.

As a result, the ferric trioxide (Fe ₂ O ₃ ) that constitutes the outermost surface is relatively hard but flexible in terms of crystal structure, so that the attack of the opponent is reduced, the initial adaptability is improved, and the reliability is improved. improves.

According to a third invention, in the first or second invention, the silicate (Si oxide) contained in the oxide film contains one or both of silicon dioxide (SiO ₃ ) and firelite (Fe 2 SiO ₄ ). As a configuration.

  Thereby, it has a hard part in a film | membrane, and also abrasion resistance improves, and also the adhesiveness of a base material and an oxide film improves. That is, the film has a higher yield strength and the reliability is improved.

  According to a fourth invention, in any one of the first to third inventions, the oxide film has a thickness of 1 to 5 μm.

  As a result, the wear resistance is improved, the long-term reliability is improved, and the dimensional accuracy is stabilized, so that high productivity can be obtained.

  According to a fifth invention, in any one of the first to fourth inventions, the iron-based material serving as the sliding member includes 0.5 to 10% of silicon.

  Thereby, the adhesiveness of a base material and an oxide film improves effectively, and reliability improves by forming a high proof stress film | membrane.

  In a sixth aspect based on the fifth aspect, the iron-based material is cast iron.

  This makes it possible to reduce the cost because cast iron is inexpensive and has high productivity, and can effectively improve the adhesion between the base material and the oxide film and form a highly proof film. Improves.

  According to a seventh invention, in any one of the first to sixth inventions, the refrigerant is an HFC refrigerant such as R134a or a mixed refrigerant thereof, and the lubricating oil is ester oil, alkylbenzene oil, polyvinyl ether, polyalkylene glycol, or the like. Either one or a mixed oil of these is used.

  As a result, even when a low-viscosity lubricating oil is used, abnormal wear is prevented, sliding loss can be reduced, and reliability and efficiency are improved.

  An eighth invention is the invention according to any one of the first to sixth inventions, wherein the refrigerant is a natural refrigerant such as R600a, R290, R744 or a mixed refrigerant thereof, and the lubricating oil is mineral oil, ester oil or alkylbenzene oil, polyvinyl ether. , Any one of polyalkylene glycols, or a mixed oil thereof.

  This prevents abnormal wear even when low-viscosity lubricating oil is used, reduces sliding loss, improves reliability and efficiency, and uses global warming by using a refrigerant with less greenhouse effect. Suppression can be achieved.

  According to a ninth invention, in any one of the first to sixth inventions, the refrigerant is an HFO refrigerant such as R1234yf or a mixed refrigerant thereof, and the lubricating oil is ester oil, alkylbenzene oil, polyvinyl ether, polyalkylene glycol, or the like. Either one or a mixed oil of these is used.

  This prevents abnormal wear even when low-viscosity lubricating oil is used, reduces sliding loss, improves reliability and efficiency, and uses global warming by using a refrigerant with less greenhouse effect. Suppression can be achieved.

  In a tenth aspect of the invention, in particular, in any one of the first to ninth aspects of the invention, the electric element is driven by an inverter at a plurality of operating frequencies.

  This reduces the amount of oil supplied to each sliding part during low-speed operation, but the oxide film with excellent wear resistance can improve reliability and also during high-speed operation where the rotational speed increases. Since the high reliability can be maintained by the oxide film having excellent wear resistance, the reliability of the compressor can be further improved in addition to the effect of any one of the first to ninth inventions.

  An eleventh aspect of the present invention is a refrigeration apparatus, and the refrigeration apparatus includes a refrigerant circuit in which a compressor, a radiator, a decompression device, and a heat absorber are connected in an annular shape by piping, and the compressor is configured from the first to the tenth It is set as the sealed compressor of any one invention.

  Thereby, the power consumption of the refrigeration apparatus can be reduced by mounting the compressor with improved performance and reliability, energy saving can be realized, and reliability can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
1 is a cross-sectional view of a refrigerant compressor according to Embodiment 1 of the present invention, and FIG. 2 is an example of a result of TEM (transmission electron microscope) observation of an oxide film applied to a sliding member of the refrigerant compressor. It is an element map which shows an example of the result of having performed the TEM (transmission electron microscope) image which shows, and an EDS analysis.

  In FIG. 1, an airtight container 101 is filled with a refrigerant gas 102 made of R134a, ester oil is stored as a lubricating oil 103 at the bottom, an electric element 106 made up of a stator 104 and a rotor 105, and this The reciprocating compression element 107 driven by is accommodated.

  The compression element 107 is constituted by a crankshaft 108, a cylinder block 112, a piston 132, and the like. The configuration will be described below.

  The crankshaft 108 includes a main shaft 109 into which the rotor 105 is press-fitted and fixed, and an eccentric shaft 110 formed eccentrically with respect to the main shaft 109, and includes an oil supply pump 111 communicating with the lubricating oil 103 at the lower end.

  As is apparent from FIG. 2A, the crankshaft 108 uses gray cast iron (FC cast iron) containing about 2% of silicon (Si) in the base material 150, and an oxide film 151 is formed on the surface. Yes.

As shown in FIG. 2 (a), the oxide film 151 occupies the largest amount in order from the outermost surface 151a of the ferric trioxide (Fe ₂ O ₃ ). An intermediate portion 151b composed of a portion containing triiron tetroxide (Fe ₃ O ₄ ) and containing a silicate (Si oxide), and the most occupied component being triiron tetroxide (Fe ₃ O ₄ ) (Si oxide) and the inner part 151c which consists of a part containing a silicon (Si) solid solution part. In addition, the film thickness of the oxide film 151 in this Embodiment is about 2 micrometers.

  The cylinder block 112 is made of cast iron, forms a substantially cylindrical bore 113, and includes a bearing portion 114 that supports the main shaft 109.

  Further, the rotor 105 is formed with a flange surface 120, and the upper end surface of the bearing portion 114 is a thrust surface 122. A thrust washer 124 is inserted between the flange surface 120 and the thrust surface 122 of the bearing portion 114. A thrust bearing 126 is configured by the flange surface 120, the thrust surface 122 and the thrust washer 124.

  The piston 132 is loosely fitted to the bore 113 with a certain amount of clearance, is made of an iron-based material, and forms a compression chamber 134 together with the bore 113. Further, the piston 132 is connected to the eccentric shaft 110 via a piston pin 137 by a connecting rod 138 which is a connecting means. The end surface of the bore 113 is sealed with a valve plate 139.

  The head 140 forms a high pressure chamber and is fixed to the opposite side of the valve plate 139 to the bore 113. The suction tube (not shown) is fixed to the sealed container 101 and connected to the low pressure side (not shown) of the refrigeration cycle, and guides the refrigerant gas 102 into the sealed container 101. The suction muffler 142 is sandwiched between the valve plate 139 and the head 140.

  The operation of the refrigerant compressor configured as described above will be described below.

  Electric power supplied from a commercial power source (not shown) is supplied to the electric element 106 to rotate the rotor 105 of the electric element 106. The rotor 105 rotates the crankshaft 108, and the eccentric motion of the eccentric shaft 110 drives the piston 132 from the connecting rod 138 of the connecting means via the piston pin 137. The piston 132 reciprocates in the bore 113 and sucks the refrigerant gas 102 introduced into the sealed container 101 through a suction tube (not shown) from the suction muffler 142 and compresses it in the compression chamber 134.

  As the crankshaft 108 rotates, the lubricating oil 103 is supplied to each sliding portion from the oil supply pump 111, lubricates the sliding portion, and governs sealing between the piston 132 and the bore 113.

  Here, in order to improve the efficiency of recent refrigerant compressors, the viscosity of the lubricating oil 103 is lowered as described above, or the sliding length between the sliding portions is designed to be shorter. The sliding condition is proceeding in a severer direction, that is, in a direction in which the oil film between the sliding portions becomes thinner or is difficult to be formed.

  In addition, the refrigerant compressor has an eccentric shaft 110 and a connecting rod 138 that are formed eccentrically with respect to the main shaft 109 of the crankshaft 108, the bearing portion 114 of the cylinder block 112, and the main shaft 109 due to the gas pressure of the compressed refrigerant gas 102. A fluctuating load with a load fluctuation is applied between the two. As the load fluctuates, the refrigerant gas 102 dissolved in the lubricating oil 103 repeatedly evaporates between the main shaft 109 and the bearing 114 and foams.

  For these reasons, the oil film is cut off and the frequency of metal contact at the sliding portion such as between the main shaft portion 109 and the bearing portion 114 of the crankshaft 108 increases.

  However, since the above-mentioned oxide film 151 is applied to the sliding portion of this refrigerant compressor, for example, the sliding portion of the crankshaft 108 shown as an example in this embodiment, even if the frequency of oil film cutting increases, The wear caused by this can be suppressed over a long period of time.

  Hereinafter, this wear suppression effect, that is, the wear resistance of the oxide film 151 will be described.

First, in a ring-on-disk wear test in a mixed atmosphere of R134a refrigerant and VG3 (viscosity grade of 3 mm ² / s at 40 ° C), the base material is gray cast iron (FC cast iron). The wear resistance of the four types of surface treatments applied to the outermost surface and the aggressiveness to the mating sliding surface were evaluated.

  FIG. 3 shows the wear amount of the ring after the ring-on-disk wear test, and FIG. 4 shows the wear amount of the disc after the wear test.

As an evaluation comparison processing film of the oxide film 151 of the present embodiment, the phosphate film shown in the conventional example, a gas nitride film (Comparative Example 1) generally used as a hard film, and a conventional general film An oxide film, a so-called black dyeing treatment, or a triiron tetroxide (Fe ₃ O ₄ ) single partial coating (Comparative Example 2) that was carried out by a method called fermite treatment was used.

  In addition, about the ring which is a counterpart sliding material, the base material is made of gray cast iron, and the surface of the sliding surface after polishing is not subjected to surface treatment.

As shown in FIG. 3, when compared with the conventional phosphate coating, the amount of wear on the disk surface is reduced in any of the surface treatment coatings of the examples of the present embodiment and the comparative examples 1 and 2, It can be seen that the self-wear resistance is high. However, as for the general oxide film of Comparative Example 2 consisting of a triiron tetroxide (Fe ₃ O ₄ ) single part, traces of peeling from the substrate interface were observed in some places.

  On the other hand, as shown in FIG. 4, in the wear amount of the ring as the counterpart material, the oxide film 151 of the present embodiment is equivalent to the gas of Comparative Example 1 compared to the conventional phosphate film. It turns out that the nitride film and the general oxide film of the comparative example 2 are increasing. That is, it can be seen that the oxide film 151 of the present embodiment has a low aggressiveness to the counterpart material, similarly to the phosphate film.

  Regarding the self-abrasion resistance, since the oxide film 151 of the present embodiment is an iron oxide, it is chemically very stable and high in hardness as compared with a conventional phosphate film. Therefore, it is considered that the transfer of wear powder was effectively prevented and the wear amount of the oxide film 151 itself was reduced.

On the other hand, regarding the aggressiveness to the latter counterpart material, the oxide film 151 of the present embodiment uses the outermost portion 151a as the portion where the most occupying component is composed of ferric trioxide (Fe ₂ O ₃ ). This is considered to reduce the aggressiveness to the opponent material and improve the familiarity.

That is, the ferric trioxide (Fe ₂ O ₃ ) in the oxide film 151 of the present embodiment is derived from the gas nitride film of Comparative Example 1 or the conventional triiron tetroxide (Fe ₃ O ₄ ) single part of Comparative Example 2. Compared to the oxide film, the hardness at the particle level is low. This is because the crystal structure of diiron trioxide (Fe ₂ O ₃ ) is rhombohedral, so that the crystal structure is cubic iron tetraoxide (Fe ₃ O ₄ ), and the crystal structure is a close-packed hexagonal crystal. This is because the crystal structure is more flexible than the nitride film which is a face-centered cubic crystal and a body-centered tetragonal crystal. From this fact, the oxide film 151 of the present embodiment reduces the aggressiveness to the counterpart material as compared with the oxide film composed of a single portion of Fe ₃ O ₄ of Comparative Example 2 and the nitride film of Comparative Example 1. It is thought that the familiarity is improved.

  Next, for further detailed analysis, among the rings used in the previous ring-on-disk wear test, regarding the cross section of the oxide film 151 of the present embodiment, EDS (energy dispersive X-ray spectroscopy) Since element mapping by analysis was performed, an example of the result will be described with reference to FIG.

  First, FIG. 2A is an overall image of the oxide film 151 as described above, and shows a TEM (transmission electron microscope) image of a cross section near the sliding surface of the ring. It can be seen that the oxide film 151 is formed on the base material 150 made of gray cast iron (FC cast iron) (on the right side of the base material 150 in the image). It can be clearly confirmed from this image that the oxide film 151 has the above-described configuration, that is, the three-part structure of the outermost part 151a, the intermediate part 151b, and the inner part 151c.

  2 (b) shows the mapping result of the iron (Fe) element, FIG. 2 (c) shows the oxygen (O) element, and FIG. 2 (d) shows the mapping result of the silicon (Si) element. The density ratio is indicated by the density of the black and white portion, and the whiter the color, the higher the proportion of the corresponding element. In addition, between the broken lines described on the left and right of each figure is an oxide film 151 portion, which is formed with a width of about 2 μm from the surface.

  From these elemental analysis results, it is understood that the concentration ratio of each element in the oxide film 151 tends to be as follows.

  First, as shown in FIG. 2B, the iron (Fe) element has a region where the concentration of the iron (Fe) element is lower than that of the substrate 150 and is formed over the entire width of the oxide film 151 from about 2 μm from the surface. ing. In the oxide film 151, the iron (Fe) element concentration distribution from the outermost surface side toward the base material 150 side does not show a large concentration difference (difference in density in the black and white part), and is uniformly distributed. You can see that A part of the oxide film 151 shown in FIG. 2 (a) shows a decrease in density at a portion where the white portion 151d is formed.

  Next, as shown in FIG. 2C, the oxygen (O) element has a region where the concentration of the oxygen (O) element is higher than that of the base material 150 at about 2 μm from the surface, that is, the entire width of the oxide film 151. It is formed over. This was confirmed in the same region as the concentration distribution of the iron (Fe) element described above, and it became clear that an oxidized portion different from the base material 150 was formed. Further, as in the concentration distribution of the iron (Fe) element, the concentration distribution is uniform in the oxide film 151, with no large concentration difference being observed in the entire region from the outermost surface side to the base material 150 side direction. It can be seen that it is distributed. Note that, in part of the oxide film 151 shown in FIG. 2A, a decrease in concentration is observed in a portion where the white portion 151 d is formed, similarly to the concentration distribution of iron (Fe) element.

  Next, as shown in FIG. 2D, the concentration distribution of silicon (Si) element is high on the base material 150 side, and it has been found that the concentration distribution immediately starts to decrease at the interface between the inner portion 151c and the intermediate portion 151b. However, an increase in density is observed at the portion that becomes the white portion 151d in FIG. 2A in the intermediate portion 151b.

  From these results, in the oxide film 151, the iron (Fe) element and the oxygen (O) element are present from the inner portion 151c to the outermost portion 151a, and the silicon (Si) element is substantially present in the outermost portion 151a. It was revealed that silicon (Si) element was present in part of the intermediate part 151b and the inner part 151c.

  Next, in order to further clarify the state of the element in each part, the results of EELS (electron beam energy loss spectroscopy) analysis are shown below.

  EELS analysis is a technique for analyzing the composition and bonding state of materials of substances by measuring the energy lost by the interaction of atoms with electrons when passing through a sample. Specific energy depends on the constituent elements and electronic structure. It is clear that the waveform is shown.

  FIG. 5 shows a partial region of the cross section confirmed in FIG. 2A as iron (Fe) (FIG. 5 (1)), oxygen (O) (FIG. 5 (2)), silicon (Si) (FIG. 5 (3)). )) (The mesh portion indicated by Z in FIGS. 5 (1) to 5 (3)), and the result of mapping is shown. 5 (a) to 5 (c) shown next to FIGS. 5 (1) to 5 (3) show the same parts as FIGS. 5 (1) to 5 (3). Shows the intensity, and the whiter the color, the higher the proportion of the corresponding waveform.

From these results, the strength of each iron (Fe), oxygen (O), and silicon (Si) in the oxide film 151 showed the following tendencies.
First, as shown in FIG. 5A, the iron (Fe) element has a large strength difference in the strength distribution of iron (Fe) from the outermost surface side to the base material 150 side in the oxide film 151. It can be seen that the distribution is uniform. A part of the white portion 151d in FIG. 2 (a) shows a decrease in strength.

  Next, as shown in FIG. 5B, the oxygen (O) element is in the oxide film 151 from the outermost surface side toward the base material 150 side, as in the iron (Fe) strength distribution. The intensity distribution of oxygen (O) did not show a large difference in intensity, and it was confirmed that the distribution was uniform and an oxide film was formed. Note that, in some places in FIG. 2A, where the white portion 151d is formed, a decrease in strength is observed in the same manner as the strength distribution of iron (Fe).

  Next, as shown in FIG. 5C, it was found that the strength distribution of the silicon (Si) element is high on the substrate 150 side, and starts to decrease at the interface between the inner portion 151c and the intermediate portion 151b. However, an increase in strength is observed at the portion that becomes the white portion 151d in FIG. 2A in the intermediate portion 151b.

  From these results, the same tendency is observed in the EELS analysis as in the above-described EDS analysis, that is, the oxide film 151 has an iron (Fe) element and oxygen (O) from the inner portion 151c to the outermost portion 151a. It is confirmed that the element is present, the silicon (Si) element is substantially absent in the outermost part 151a, and the silicon (Si) element is present in a part of the intermediate part 151b and the inner part 151c. It was.

  Next, the EELS analysis was further advanced to confirm in detail the types of elements in each part confirmed as described above. The results will be described below.

FIG. 6A is an enlarged waveform of a portion corresponding to iron (Fe) in the EELS waveform of the outermost portion 151a. This waveform shows a typical ferric trioxide (Fe ₂ O ₃ ). FIG. 6A shows the result of mapping the location that matches the peak of this waveform. In FIG. 5 (a) mapped on the whole of iron (Fe), no intensity distribution was observed, but when limited to diiron trioxide (Fe ₂ O ₃ ), the black and white portion was very light in the outermost portion 151a. It showed high strength, and it became clear that the outermost part 151a was substantially composed of ferric trioxide (Fe ₂ O ₃ ).

FIG. 7A is an enlarged waveform of a portion corresponding to iron (Fe) in the EELS waveform of the intermediate portion 151b. This waveform is a typical waveform indicating triiron tetroxide (Fe ₃ O ₄ ), and the same waveform was confirmed in the portion corresponding to iron (Fe) in the other intermediate portion 151b. From this, it became clear that the intermediate portion 151b is mainly composed of triiron tetroxide (Fe ₃ O ₄ ).

  FIG. 7 (2-1, 2-2) is an enlarged waveform of the same portion corresponding to oxygen (O) in the EELS waveform of the white portion 151d of the intermediate portion 151b. In FIG. 7 (2-1), a peak is seen near 525 eV, while in FIG. 7 (2-2), no peak is seen. Since the peak in the vicinity of 525 eV is a characteristic peak found in iron oxide, it is clear that oxygen (O) exists in a structure that does not bind to iron (Fe) at the measurement location in FIG. It became.

  FIG. 7 (3-1, 3-2) is an enlarged waveform of the same portion corresponding to silicon (Si) in the EELS waveform of the white portion 151d of the intermediate portion 151b. FIGS. 7 (2-1) and (2-2) and FIGS. 7 (3-1) and (3-2) are EELS waveforms at the same location. FIG. 7 (3-1) and FIG. 7 (3-2) show substantially the same waveform, and it became clear from the shape that silicon (Si) in a state of being bonded to oxygen (O) is present.

From the results of FIGS. 7 (2-1, 2-2) and 7 (3-1, 3-2), the white portion 151d of the intermediate portion 151b is not bonded to iron (Fe), but is silicon (Si) and oxygen. There are silicates (Si oxides) with different structures such as silicon dioxide (SiO ₂ ) bonded with (O) and firelite (Fe ₂ SiO ₄ ) bonded with iron (Fe), silicon (Si) and oxygen (O). It became clear that

Furthermore, the enlarged waveform of the portion corresponding to iron (Fe) in the EELS waveform of the black portion of the inner portion 151c showed substantially the same shape as in FIG. From this, it became clear that the inner portion 151c is mainly composed of triiron tetroxide (Fe ₃ O ₄ ) as in the intermediate portion 151b.

  FIG. 8 is an enlarged waveform of a portion corresponding to silicon (Si) in the EELS waveform of the inner portion 151c. Since this waveform has a shape different from that of FIG. 7 (3-1, 3-2) and the state of being bonded to oxygen (O) cannot be confirmed, silicon (Si) is present in a solid solution state at this point. It is suggested that Moreover, since the same waveform as FIG.7 (2-1) and FIG.7 (3-1) was confirmed in the other location of the inner part 151c, it is clear that silicate (Si oxide) exists. It became.

From the results of the above analysis, the oxide film 151 according to the embodiment of the present invention has the outermost portion 151a in which the most occupied component is composed of ferric trioxide (Fe ₂ O ₃ ) and the most occupied component in the trioxide tetraoxide. An intermediate portion 151b composed of a portion containing silicate (Si oxide) with iron (Fe ₃ O ₄ ), and the most occupying component is triiron tetroxide (Fe ₃ O ₄ ) and silicate (Si oxide). It was revealed that the inner portion 151c is composed of a portion including a silicon (Si) solid solution portion.

  Next, in order to confirm the superiority (effect) of the oxide film 151 in the embodiment of the present invention, a reliability test of an actual machine was performed under a high-load operating condition using the crankshaft 108 provided with the oxide film 151. The results will be described next.

  FIG. 9 shows a TEM (transmission electron microscope) image of a cross section near the sliding surface of the crankshaft 108 after the reliability test. It can be seen that the oxide film 151 is formed on the base material 150 made of gray cast iron (FC cast iron) (on the right side of the base material 150). Even after the reliability test, the oxide film 151 has a three-part structure of the outermost part 151a, the intermediate part 151b, and the inner part 151c, and it was confirmed that the configuration state of each part was not changed.

Based on the above results, the action of the outermost portion 151a in which the most occupied component is composed of ferric trioxide (Fe ₂ O ₃ ) will be considered.

As shown in the results of the wear test, the crystal structure of ferric trioxide (Fe ₂ O ₃ ) is more flexible in terms of crystal structure than that of triiron tetroxide (Fe ₃ O ₄ ) and nitride coatings. By having become, it has the effect | action which improves the adaptability while reducing the aggression property to an other party material.

In addition, the results of the reliability test show that the oxide film 151 of the present embodiment has no wear after the reliability test and shows high wear resistance, and ferric trioxide (Fe ₂ O ₃ ). Has the effect of increasing self-abrasion resistance.

This is because the hardness, which is a mechanical property directly linked to wear, is about 537 Hv in the outermost portion 151a of ferric trioxide (Fe ₂ O ₃ ), whereas in the case of triiron tetroxide (Fe ₃ Since the hardness of O ₄ ) is about 420 Hv and ferric trioxide (Fe ₂ O ₃ ) is higher, the conventional general oxidation of Comparative Example 2 consisting of a single portion of triiron tetroxide (Fe ₃ O ₄ ). It is presumed that a portion having higher wear resistance than the coating was formed. Further, since the silicate (Si oxide) contained in the intermediate portion 151b and the inner portion 151c is generally harder than the oxide, even if the outermost portion 151a is worn, the intermediate portion 151b and the inner portion 151c itself It is presumed that the wear resistance superior to that of the conventional general oxide film of Comparative Example 2 is exhibited.

Next, consideration will be given to the fact that the adhesion (proof strength) of the film is higher than that of a conventional oxide film consisting of a single portion of triiron tetroxide (Fe ₃ O ₄ ).

  The reason why the adhesion (yield strength) of the film is high is considered as follows. That is, Kobe Steel Engineering Reports Vol. According to 1.55 (No. 1 Apr. 2005), an oxide film (scale) is generated on the surface of the steel sheet in the hot rolling process of the steel material, and it is removed as the amount of silicon contained in the steel material increases. There is a description that the scale property is lowered. From this, the oxidation product composed of silicon and iron reinforces the adhesion of the oxide film 151 as in the present embodiment, and as a result, the proof stress against the load during sliding is improved and peeling It is thought that this was prevented.

From the above, according to the present embodiment, the most occupied component is ferric trioxide (Fe ₂ O ₃ ) and the most occupied component on the sliding surface of the sliding member that is an iron-based material. A portion containing trisilicate tetroxide (Fe ₃ O ₄ ) containing silicate (Si oxide), and the most occupied component is triiron tetroxide (Fe ₃ O ₄ ) and silicate (Si oxide) and silicon (Si) By providing the oxide film which consists of a part containing a solid solution part, while a sliding member improves abrasion resistance, the adhesiveness of a base material and an oxide film improves.

  In addition, although the film thickness was about 2 μm in the oxide film 151 of the present embodiment, the same effect can be obtained if the film thickness is in the range of 1 to 5 μm. On the other hand, when the film thickness is less than 1 μm, it is difficult to maintain the proof stress for a long period of time, and conversely, when it is thicker than 5 μm, the surface roughness becomes excessive, and accuracy control of the sliding parts of the refrigerant compressor can be performed. It can be difficult.

  Moreover, although the gray cast iron (FC cast iron) which contains about 2% of silicon was used for the base material 150 of this Embodiment, generally about 1-3% of silicon is normally contained in cast iron. For example, the same effect can be obtained by using spheroidal graphite cast iron (FCD cast iron) or the like. Further, as a raw material, a steel material or a sintered material to which silicon is added in an amount of about 0.5 to 10% can be used. Similar effects can be obtained.

  In this embodiment, the refrigerant is R134a refrigerant and the lubricating oil is ester oil. However, any one of other HFC (hydrofluorocarbon) refrigerants or a mixed refrigerant thereof is used, and the lubricating oil is alkylbenzene oil or polyvinyl ether. The same effect can be obtained by using any one of polyalkylene glycol or a mixed oil thereof.

  The refrigerant is any one of natural refrigerants such as R600a, R290, R744, etc., or a mixed refrigerant containing these, and the lubricating oil is any one of mineral oil, ester oil or alkylbenzene oil, polyvinyl ether, polyalkylene glycol, or these. The same effect can be obtained by using a mixture of the above, and global warming can be suppressed by using a refrigerant having a small greenhouse effect.

  In addition, any one of HFO (hydrofluoroolefin) refrigerants or a mixed refrigerant thereof may be used, and any one of ester oil, polyalkylene glycol, polyvinyl ether, mineral oil, or a mixed oil thereof may be used as the lubricating oil. The same effect can be obtained, and global warming can be suppressed by using a refrigerant having a small greenhouse effect.

  As described above, the reciprocating refrigerant compressor has been described as an example in the present embodiment. However, the same effect can be obtained in other compressors having a sliding portion and a discharge valve such as a rotary type, a scroll type, and a vibration type. It goes without saying that it is obtained.

  In the present embodiment, the refrigerant compressor driven by a commercial power source has been described. However, the refrigerant compressor driven by an inverter at a plurality of operating frequencies also has excellent wear resistance as in the present embodiment. By forming the oxide film 151 on the sliding surface of the iron-based material, the reliability can be improved even during low speed operation where the amount of oil supplied to each sliding portion decreases or during high speed operation where the rotational speed increases. .

(Embodiment 2)
FIG. 10 shows a refrigeration apparatus using the refrigerant compressor according to Embodiment 1 of the present invention. Here, only the outline of the basic configuration of the refrigeration apparatus will be described.

  In FIG. 10, the refrigeration apparatus includes a heat-insulating box having an opening on one side, a main body 201 having a door structure that opens and closes the opening, and a section that divides the inside of the main body 201 into an article storage space 203 and a machine room 205. A wall 207 and a refrigerant circuit 209 for cooling the storage space 203 are provided.

  The refrigerant circuit 209 has a configuration in which the hermetic compressor described in Embodiment 1 as the compressor 211, the radiator 213, the decompression device 215, and the heat absorber 217 are connected in a ring shape. The refrigerant compressor 171 is the refrigerant compressor described in the first embodiment of the present invention.

  Moreover, the heat absorber 217 is arrange | positioned in the storage space 203 which comprised the air blower (not shown). The cooling heat of the heat absorber 217 is agitated so as to circulate in the storage space 203 by the blower as indicated by an arrow, and the storage space 203 is cooled.

The refrigeration apparatus having the above configuration is equipped with the hermetic compressor according to the first embodiment of the present invention as the compressor 211, so that the most occupied component on the sliding surface of the iron-based material is ferric trioxide ( and outermost portion 151a consisting of Fe ₂ O _3), an intermediate portion 151b most occupied component moieties comprising a silicate (Si oxide) with triiron tetraoxide (Fe ₃ O _4), occupying most By applying an oxide film 151 composed of an inner portion 151c composed of a portion containing triiron tetroxide (Fe ₃ O ₄ ) and containing a silicate (Si oxide) and a silicon (Si) solid solution portion, wear resistance is increased. As a result, the adhesion between the base material 150 and the oxide film is improved, the viscosity of the lubricating oil can be made lower, and the sliding length between the sliding parts can be designed to be shorter, thereby reducing the sliding loss. Because it improves reliability and performance, Power consumption can be reduced, the life-and-death realize energy saving, thereby improving the reliability.

  As described above, the present invention can provide a compressor having high reliability while using a low-viscosity lubricating oil and a refrigeration apparatus using the compressor, and can be widely applied to various apparatuses using a refrigeration cycle. .

DESCRIPTION OF SYMBOLS 101 Airtight container 103 Lubricating oil 106 Electric element 107 Compression element 150 Base material 151 Oxide film 151a Outermost part 151b Middle part 151c Inner part 151d White part 209 Refrigerant circuit 211 Compressor 213 Radiator 215 Decompression device 217 Heat absorber

Claims (11)

The lubricating oil is stored in a sealed container, and the electric element and the compression element that is driven by the electric element and compresses the refrigerant are housed. At least one sliding member that constitutes the compression element is an iron-based material. In the sliding surface of the iron-based material, the most occupied component is ferric trioxide (Fe ₂ O ₃ ) and the most occupied component is triiron tetroxide (Fe ₃ O ₄ ). An oxide film comprising a portion containing (Si oxide) and a portion containing the silicate (Si oxide) and silicon (Si) solid solution portion, the most occupying component being triiron tetroxide (Fe ₃ O ₄ ) Refrigerant compressor that has been subjected to. In order from the outermost surface, the oxide film is composed of the outermost part composed of ferric trioxide (Fe ₂ O ₃ ) as the most occupying component and the triiron tetroxide (Fe ₃ O ₄ ) as the most occupying component. From an intermediate part composed of a part containing (Si oxide) and from a part containing the silicate (Si oxide) and silicon (Si) solid solution part, the most occupying component is triiron tetroxide (Fe ₃ O ₄ ) The refrigerant compressor according to claim 1, further comprising an inner portion. The refrigerant compressor according to claim 1 or 2, wherein the silicate (Si oxide) contained in the oxide film includes one or both of silicon dioxide (SiO ₃ ) and firelite (Fe ₂ SiO ₄ ). The refrigerant compressor according to any one of claims 1 to 3, wherein the oxide film has a total film thickness of 1 to 5 µm. The refrigerant compressor according to any one of claims 1 to 4, wherein the iron-based material serving as the sliding member contains about 0.5 to 10% of silicon. The refrigerant compressor according to claim 5, wherein the iron-based material is cast iron. 7. The refrigerant according to claim 1, wherein the refrigerant is an HFC refrigerant such as R134a or a mixed refrigerant thereof, and the lubricating oil is one of ester oil, alkylbenzene oil, polyvinyl ether, polyalkylene glycol, or a mixed oil thereof. The refrigerant compressor according to one item. The refrigerant is a natural refrigerant such as R600a, R290, R744 or a mixed refrigerant thereof, and the lubricating oil is any one of mineral oil, ester oil, alkylbenzene oil, polyvinyl ether, polyalkylene glycol, or a mixed oil thereof. To 6. The refrigerant compressor according to any one of items 6 to 6. The refrigerant is an HFO refrigerant such as R1234yf or a mixed refrigerant thereof, and the lubricating oil is any one of ester oil, alkylbenzene oil, polyvinyl ether, polyalkylene glycol, or a mixed oil thereof. The refrigerant compressor according to one item. The refrigerant compressor according to any one of claims 1 to 9, wherein the electric element is configured to be inverter-driven at a plurality of operating frequencies. A refrigerating apparatus comprising a refrigerant circuit in which a compressor, a radiator, a decompression device, and a heat absorber are connected in an annular shape by piping, wherein the compressor is the hermetic compressor according to any one of claims 1 to 10. .

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