JP2009235969A - Rotary compressor and refrigerating cycle apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary compressor that can realize prevention of degradation of machinability of a vane, in addition to enhancement of wear resistance of the vane. <P>SOLUTION: In a rotary compressor including a rotary compression mechanism unit for compressing coolant, the rotary compression mechanism unit includes a cylinder 11b for forming a cylinder chamber 10b, a roller 12b rotatably provided in the cylinder chamber 10b, and a vane 13b reciprocally provided in the cylinder 11b in contact with an outer circumferential surface of the roller 12b, for separating the interior of the cylinder chamber 10b into a suction chamber H1 and a compression chamber H2 together with the roller 12b. A coating film 24 including amorphous carbon layer is formed on a front edge surface M1 of the roller 12b side in the vane 13b and one side surface M2 out of both side surfaces that slidingly move with respect to the cylinder 11b, but the coating film 24 is not formed on the other side surface M3 out of both of the side surfaces. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotary compressor and a refrigeration cycle apparatus, and more particularly to a refrigerant compressor and a refrigeration cycle apparatus including a rotary compression mechanism unit that compresses a refrigerant.

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

  As an example of such a refrigerant compressor, those described in Patent Document 1 and Patent Document 2 below are known, and are connected to a motor case and the motor unit through a rotating shaft in a sealed case. The compression mechanism part is accommodated. A cylinder is provided in the compression mechanism, an eccentric roller is disposed in the cylinder, a vane as a sliding member is incorporated in the vane groove of the cylinder, and the tip of the vane elastically contacts the peripheral surface of the eccentric roller. Has been. When the electric motor unit is driven and the eccentric roller rotates, the vane slides with respect to the eccentric roller and the vane groove. The vane is required to have a dimensional tolerance on the order of microns, and finish processing (for example, dimensional processing) by polishing is performed.

  Usually, the vane has its front end surface pressed against the eccentric roller by a spring, and is further easily worn because it is pressed against the eccentric roller due to the pressure difference between the high pressure in the sealed case and the cylinder chamber. In addition, due to the pressure difference between the suction chamber and the compression chamber in the cylinder chamber, a force is applied to the vane from the compression chamber side toward the suction chamber side, and the side surface of the vane facing the suction chamber side is stronger than the vane groove of the cylinder. Wears easily because it slides in contact.

Therefore, a coating containing an amorphous carbon layer or a protective film containing carbon or carbon as a main component is formed on the surface of the vane in order to suppress wear due to sliding with each part. The vane described in Patent Document 1 below has a single layer or two layers of amorphous carbon layers. In the case of two layers, the lower layer (base material side of the vane) is a hydrogen-containing amorphous carbon layer, and the upper layer is a metal-containing amorphous layer. It is a carbon layer. On the other hand, carbon or a protective film mainly composed of carbon is formed on all sides of the vane described in Patent Document 2 below.
JP 2007-32360 A Japanese Patent Laid-Open No. 7-119662

  However, if a coating (protective film) is applied to the surface of the vane as described above, the wear resistance of the vane can be improved, but finishing processing (for example, dimensional processing) is performed on the vane after coating. This makes it difficult to process the vane.

  The present invention has been made to solve such a problem, and its purpose is to improve the wear resistance of the vane, and to provide a rotary compressor capable of preventing the vane workability from being lowered and A refrigeration cycle apparatus is provided.

  A first feature according to an embodiment of the present invention is that, in the rotary compressor including a rotary compression mechanism unit that compresses the refrigerant, the rotary compression mechanism unit is rotatable in a cylinder chamber and a cylinder that forms a cylinder chamber. And a vane that is provided in the cylinder so as to be able to reciprocate in contact with the outer peripheral surface of the roller and separates the cylinder chamber into a suction chamber and a compression chamber together with the roller. A film including an amorphous carbon layer is formed on one side surface of the tip surface and both side surfaces sliding with the cylinder, and a film is not formed on the other side surface of both side surfaces.

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

  ADVANTAGE OF THE INVENTION According to this invention, in addition to the improvement of the abrasion resistance of a vane, the rotary compressor and refrigeration cycle apparatus which can implement | achieve the fall prevention of the processability of a vane can be provided.

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

(First embodiment)
FIG. 1 is a schematic diagram showing a refrigeration cycle apparatus 1 including a refrigerant compressor according to a first embodiment of the present invention.

  The refrigeration cycle apparatus 1 includes a closed rotary refrigerant compressor (rotary compressor) 2, a condenser 3, an expansion device 4, and an evaporator 5. The refrigeration cycle apparatus 1 uses an HFC refrigerant, an HC (hydrocarbon-based) refrigerant, or a carbon dioxide refrigerant as a refrigerant. The refrigerant compressor 2 is a two-cylinder type and includes a sealed case 2a. In the sealed case 2a, the electric motor unit 6 and the rotary compression mechanism unit 7 are accommodated, and the electric motor unit 6 and the rotary compression mechanism unit 7 are connected via a rotary shaft 8 having eccentric portions 8a and 8b.

  The electric motor unit 6 includes a rotor 6a and a stator 6b, and may be a brushless DC synchronous motor driven by an inverter, an AC motor, or a motor driven by a commercial power source.

  Refrigerating machine oil 9 that lubricates the rotary compression mechanism 7 is stored at the bottom of the sealed case 2a. As the refrigerating machine oil 9, a single oil or mixed oil of polyol ester oil, ether oil, mineral oil, alkylbenzene oil, and PAG oil is used.

  The rotary compression mechanism unit 7 includes a first compression mechanism unit 7a and a second compression mechanism unit 7b, and each compression mechanism unit 7a, 7b includes cylinders 11a, 11b forming cylinder chambers 10a, 10b. Yes. Rollers 12a and 12b that rotate eccentrically (revolve) are provided in the cylinder chambers 10a and 10b. The cylinders 11a and 11b reciprocate in contact with the outer peripheral surfaces of the rollers 12a and 12b, and slide members that partition the cylinder chambers 10a and 10b into a suction chamber H1 and a compression chamber H2 (see FIGS. 2 and 3). The vanes 13a and 13b (only the vane 13b is shown in FIG. 1) are disposed.

  Here, FIG. 2 is a perspective view showing the cylinder 11b, the roller 12b, and the vane 13b constituting the second compression mechanism portion 7b. FIG. 3 is a plan view showing a cylinder 11b, a roller 12b, and a vane 13b constituting the second compression mechanism portion 7b partially enlarged. The first compression mechanism unit 7a has the same configuration as the second compression mechanism unit 7b, and the first compression mechanism unit 7a includes a cylinder 11a, a roller 12a, a vane 13a, and the like.

  The vanes 13a and 13b are urged to the outer peripheral surfaces of the rollers 12a and 12b by an urging member S such as a spring (see FIG. 3). The vanes 13a and 13b are also pressed against the outer peripheral surfaces of the rollers 12a and 12b by a pressure difference between the high pressure in the sealed case 2a and the cylinder chambers 10a and 10b. Accordingly, as the rollers 12a and 12b rotate, the tip surfaces of the vanes 13a and 13b slide with the outer peripheral surfaces of the rollers 12a and 12b, and both side surfaces of the grooves 14a and 14b formed in the cylinders 11a and 11b (see FIG. 2 and FIG. 3, only the groove 14b is shown). A suction hole K1 communicates with the suction chamber H1 in the cylinder chambers 10a and 10b, and a blowout notch K2 is formed in the compression chamber H2 (see FIG. 3).

  The cylinder chamber 10a of the first compression mechanism portion 7a is covered with a main bearing 15 as a lid member and a partition plate 16. The cylinder chamber 10b of the second compression mechanism portion 7b is covered with a sub bearing 17 as a lid member and a partition plate 16. The main bearing 15 and the sub-bearing 17 are provided with discharge holes 18a and 18b and discharge valves 19a and 19b, respectively.

  A discharge pipe 20 for discharging compressed refrigerant gas is connected to the upper surface of the sealed case 2a, and a suction pipe 21 and an accumulator 22 are connected to the lower side of the side surface of the sealed case 2a.

  FIG. 4 is a cross-sectional view showing the vane 13b. FIG. 5 is an enlarged cross-sectional view showing a part of the tip of the vane 13b.

  The vane 13b is formed using a high-speed tool steel (SKH51) tempered to a hardness HRC63 as a base material 23. A coating 24 is provided on one side surface M2 of the side surface M2 and M3 of the vane 13b on the roller 12b side that slides on the roller 12b side, and on the other side surface M3 of the side surfaces M2 and M3. Is not provided with a coating 24. The one side surface M2 is a side surface of the vane 13b on the suction chamber H1 side. That is, the vane 13b is incorporated in the groove 14b of the cylinder 11b with the front end surface M1 on which the coating 24 is laminated facing the roller 12b and the one side surface M2 on which the coating 24 is laminated on the suction chamber H1. (See FIG. 3).

  The coating 24 consists of a first layer 24a composed of a single layer of chromium (Cr), and chromium and tungsten carbide (WC) in order on the surface of the base material 23 (only the front end face M1 and one side face M2). A second layer 24b made of an alloy layer, a third layer 24c made of an amorphous carbon layer containing tungsten (W), and a fourth layer made of an amorphous carbon layer containing no metal and containing carbon and hydrogen. 24d are laminated (see FIG. 5). The third layer 24c 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 24b has a chromium content higher on the first layer 24a side than the third layer 24c, and a tungsten carbide content on the third layer 24c side than the first layer 24a side. It is formed to be higher. Further, the third layer 24c is formed so that the content of tungsten is higher on the second layer 24b side than on the fourth layer 24d side.

  The thickness of each layer 24a, 24b, 24c, 24d is 0.2 μm for the first layer 24a, 0.3 μm for the second layer 24b, 1.25 μm for the third layer 24c, and 1.25 μm for the fourth layer 24d. It is 1.25 μm, and is 3 μm as a whole. Considering the reliability of the coating 24 composed of the layers 24a to 24d, the coating 24 preferably has a thickness of 2 to 5 μm.

  The surface hardness of the coating 24 is HV (0.025) 2500. The surface hardness of the coating 24 affects the wear characteristics, but if it is less than HV (0.025) 2000, the effect of the amorphous carbon layer as a high hardness material cannot be exhibited. On the other hand, when the hardness is higher than HV (0.025) 4000, the mating material may be worn, and therefore the surface hardness of the coating 24 is preferably HV (0.025) 2000 to 4000.

  FIG. 6 is an explanatory diagram for explaining a film forming process for the vane 13b.

  The two base materials 23 are superposed with one side face M3 facing each other. The base material 23 in this state is subjected to a film formation process for laminating the film 24 (a film formation process for laminating the layers 24a to 24d), and then the two base materials 23 are separated. Thereby, the coating film 24 is formed on the front end surface M1 and the one side surface M2, and two vanes 13b on which the coating film 24 is not formed are simultaneously formed on the other side surface M3. In this way, since the two base materials 23 are overlapped with the one side surface M3 facing each other, the one side surface M3 is masked with each other, so that the front end surface M1 and both side surfaces of the vane 13b. The coating 24 can be formed only on one side surface M2 of M2 and M3, and two vanes 13b described above can be manufactured simultaneously. As a result, a reduction in processing costs can be realized.

  As described above, according to the vanes 13a and 13b according to the present embodiment, the end surfaces M1 on the rollers 12a and 12b side of the vanes 13a and 13b and the side surfaces M2 and M3 that slide on the cylinders 11a and 11b. A film 24 including an amorphous carbon layer is formed only on one side surface M2. As a result, wear of the tip surfaces M1 of the vanes 13a and 13b due to the rotation of the rollers 12a and 12b and wear of the one side surface M2 of the vanes 13a and 13b due to reciprocation of the vanes 13a and 13b are suppressed. In addition, since the coating 24 is not formed on the other side surface M3 of the side surfaces M2 and M3 that slide with the cylinders 11a and 11b, the processing of the vanes 13a and 13b (for example, dimensional processing or the like) from the other side surface M3 side. Can be easily performed. In this way, it is possible to prevent the workability of the vanes 13a and 13b from being lowered while improving the wear resistance of the vanes 13a and 13b.

  In particular, due to the pressure difference between the suction chamber H1 and the compression chamber H2 in the cylinder chambers 10a and 10b, a force F (see FIG. 3) from the compression chamber H2 side to the suction chamber H1 side is applied to the vanes 13a and 13b. The side surface M2 facing the suction chamber H1 side of the vanes 13a, 13b is apt to wear because it slides in strong contact with the grooves 14a, 14b of the cylinders 11a, 11b, but the hard coating 24 is sucked into the suction chambers of the vanes 13a, 13b. Since it is formed on the one side surface M2 on the H1 side, it becomes possible to reliably reduce the wear of the vanes 13a and 13b due to the compression differential pressure, so that long-term reliability of the product can be ensured. it can.

  The coating 24 forms a first layer 24a, a second layer 24b, a third layer 24c, and a fourth layer 24d in this order on the surface of the base material 23 of the vane 13b made of high-speed tool steel. The first layer 24a is a single layer of chromium, the second layer 24b is an alloy layer of chromium and tungsten carbide, and the third layer 24c is at least of tungsten and tungsten carbide. It is a metal-containing amorphous carbon layer containing one, and the fourth layer 24d is an amorphous carbon layer containing no metal and containing carbon and hydrogen. Further, the second layer 24b has a chromium content higher on the first layer 24a side than on the third layer 24c side, and a tungsten carbide content on the third layer 24c than on the first layer 24a side. The third layer 24c is formed so that the content of tungsten or tungsten carbide is higher on the second layer 24b side than on the fourth layer 24d side.

  For this reason, the first layer 24a becomes a chromium layer having excellent adhesion to the base material 23, and between the first layer 24a and the second layer 24b, the second layer 24b and the third layer 24c. And the difference in hardness between the third layer 24c and the fourth layer 24d becomes small. Thereby, the adhesiveness between these layers 24a to 24d is improved, and the occurrence of peeling of the fourth layer (amorphous carbon layer) 24d from the vane 13b and the coating 24 including the fourth layer 24d is suppressed. be able to.

  Usually, a nitride layer is formed on the surface of the base material of the vane, and further, an intermediate layer and an amorphous carbon layer are formed thereon. The formation of the nitride layer, the intermediate layer, and the amorphous carbon layer is respectively Since the processes are different, a continuous processing furnace and a processing program are necessary for continuous processing, and there are manufacturing restrictions and the cost is high. In addition, since the nitride layer causes a significant decrease in adhesion when the nitrogen compound layer is present on the surface, the surface of the nitride layer is only the diffusion layer. There are a method of removing the nitrogen compound layer and a method of not generating the nitrogen compound layer by nitriding treatment as a method of making the surface of the nitride layer only the diffusion layer. In the case of removing the nitrogen compound, it is difficult to maintain the accuracy of the parts, which causes a decrease in yield due to processing loss and the like. On the other hand, when the nitrogen compound layer is not generated by nitriding, the surface roughness of the base material of the vane is deteriorated by nitriding, and the surface roughness of the amorphous carbon layer is also deteriorated.

  However, according to the vanes 13a and 13b according to the present embodiment, it is not necessary to form the nitride layer on the base material 23 of the vanes 13a and 13b as described above, and the first layer 24a to the fourth layer 24d are not formed. Since there is no step of forming a nitride layer, which is a process different from the formation, an inexpensive structure can be obtained. Therefore, when an amorphous carbon layer is formed on the vanes 13a and 13b, the peeling of the amorphous carbon layer can be suppressed with an inexpensive structure. In addition, since the nitriding process is not performed on the base material 23 of the vane 13b, the surface roughness of the base material 23 does not increase with the nitriding process, and the surface roughness of the fourth layer 24d is made smooth. can do.

  In the present embodiment, the case where high-speed tool steel (SKH51) is used as the base material 23 of the vanes 13a and 13b has been described as an example. However, carbon tool steel and alloy tools are used instead of high-speed tool steel. Steel may be used. The coating 24 may also be formed on the upper and lower end surfaces of the vanes 13a and 13b (both end surfaces parallel to the reciprocating direction of the vanes 13a and 13b) and the end surface on the biasing member S side.

(Second Embodiment)
A vane 30 that is a sliding member of a refrigerant compressor according to a second embodiment of the present invention will be described with reference to FIGS. The basic configuration of the refrigerant compressor is the same as that of the refrigerant compressor 2 of the first embodiment shown in FIG. 1, and the description of the configuration of the refrigerant compressor is omitted.

  The vane 30 of the second embodiment is formed using a high-speed tool steel (SKH51) tempered to a hardness HRC63 as a base material 23. A diffusion layer 25 having a thickness of, for example, 50 μm is formed on the entire surface of the base material 23 by nitriding that does not generate a white layer. A coating 24 is provided on one side surface M2 of both the side surfaces M2 and M3 sliding on the roller 12b side end surface M1 and the cylinder 11b in the vane 30, and no coating 24 is provided on the other side surface M3. . The one side surface M2 is a side surface of the vane 13b on the suction chamber H1 side.

  The coating 24 is in order on the diffusion layer 25 of the base material 23, a first layer 24a made of a single layer of chromium (Cr), and a second layer made of an alloy layer of chromium and tungsten carbide (WC). 24b, a third layer 24c made of an amorphous carbon layer containing tungsten (W), and a fourth layer 24d made of an amorphous carbon layer containing no metal and containing carbon and hydrogen. (See FIG. 8). The third layer 24c 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 24b has a chromium content higher on the first layer 24a side than the third layer 24c, and a tungsten carbide content on the third layer 24c side than the first layer 24a side. It is formed to be higher. Further, the third layer 24c is formed so that the content of tungsten is higher on the second layer 24b side than on the fourth layer 24d side.

  The thickness of each layer 24a, 24b, 24c, 24d is 0.2 μm for the first layer 24a, 0.3 μm for the second layer 24b, 1.25 μm for the third layer 24c, and 1.25 μm for the fourth layer 24d. It is 1.25 μm, and is 3 μm as a whole. Considering the reliability of the coating 24 composed of the layers 24a to 24d, the coating 24 preferably has a thickness of 2 to 5 μm.

  The surface hardness of the coating 24 is HV (0.025) 2500. The surface hardness of the coating 24 affects the wear characteristics, but if it is less than HV (0.025) 2000, the effect of the amorphous carbon layer as a high hardness material cannot be exhibited. On the other hand, when the hardness is higher than HV (0.025) 4000, the mating material may be worn, and therefore the surface hardness of the coating 24 is preferably HV (0.025) 2000 to 4000.

  In such a configuration, according to the vane 30 according to the present embodiment, the same effects as those of the first embodiment can be obtained, and further, the coating film 24 in the first embodiment is not formed. By forming the diffusion layer 25 on the other side surface M3, it becomes possible to reduce the wear of the vanes 13a and 13b sliding with respect to the side surfaces of the grooves 14a and 14b of the cylinders 11a and 11b. Can be ensured. In addition, by making the diffusion layer 25 a diffusion layer having no white layer, the aggressiveness against the cylinders 11a and 11b as the counterpart parts is reduced, and the adhesion with the coating 24 including the amorphous carbon layer is also improved. Peeling can be prevented.

(Third embodiment)
A vane 40 that is a sliding member of a refrigerant compressor according to a third embodiment of the present invention will be described with reference to FIG. The basic configuration of the refrigerant compressor is the same as that of the refrigerant compressor 2 of the first embodiment shown in FIG. 1, and the description of the configuration of the refrigerant compressor is omitted, and the first embodiment. Different parts will be described.

  In the vane 40 of the third embodiment, the coating 24 on the tip surface M1 of the vane 40 is formed so that the film thickness gradually decreases toward the other side surface M3 on the compression chamber H2 side. That is, the coating 24 on the front end face M1 is formed to be tapered toward the ridgeline at the corner of the vane 40. Therefore, the coating 24 on the tip surface M1 of the vane 40 has an inclined surface Ma that is gradually inclined in the direction in which the film thickness decreases toward the other side surface M3.

  In such a configuration, according to the vane 40 according to the present embodiment, the same effect as in the first embodiment can be obtained, and further, the other end of the vane 40 on the compression chamber H2 side can be obtained. When finishing the vanes 13a and 13b (for example, dimensional processing) from the other side M3 side by forming the coating 24 so that the film thickness gradually decreases toward the side M3, as shown in FIG. Since the processing on the hard coating 24 can be reduced as much as possible, peeling or damage of the coating 24 due to processing can be prevented.

It is the schematic which shows the refrigerating cycle apparatus provided with the refrigerant compressor which concerns on the 1st Embodiment of this invention. It is a perspective view which shows the cylinder, roller, and vane which comprise a part of refrigerant compressor. It is a top view which expands and shows partially the cylinder which comprises some refrigerant compressors, a roller, and a vane. It is sectional drawing which shows a vane. It is sectional drawing which expands and shows a part of front-end | tip part of the vane shown in FIG. It is explanatory drawing for demonstrating the film formation process with respect to a vane. It is sectional drawing which shows the vane in the 2nd Embodiment of this invention. It is sectional drawing which expands and shows a part of front-end | tip part of the vane shown in FIG. It is sectional drawing which expands and shows the front-end | tip part of the vane in the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Refrigeration cycle apparatus, 2 ... Rotary compressor, 3 ... Condenser, 4 ... Expansion apparatus, 5 ... Evaporator, 7 ... Rotary compression mechanism part (compression mechanism part), 10a ... Cylinder chamber, 10b ... Cylinder chamber, 11a ... cylinder, 11b ... cylinder, 12a ... roller, 12b ... roller, 13a ... vane, 13b ... vane, 24 ... coating, 24a ... first layer, 24b ... second layer, 24c ... third layer, 24d ... 4th layer, H1 ... Suction chamber, H2 ... Compression chamber, M1 ... End face, M2 ... One side, M3 ... Other side

Claims (5)

In the rotary compressor provided with a rotary compression mechanism that compresses the refrigerant,
The rotary compression mechanism is
A cylinder forming a cylinder chamber;
A roller rotatably provided in the cylinder chamber;
A vane that is provided in the cylinder so as to be able to reciprocate in contact with the outer peripheral surface of the roller, and separates the cylinder chamber into a suction chamber and a compression chamber together with the roller;
It has
A film including an amorphous carbon layer is formed on one side surface of the vane on the tip end surface on the roller side and both side surfaces sliding with the cylinder, and the film is formed on the other side surface of the both side surfaces. A rotary compressor characterized by not being provided.   The rotary compressor according to claim 1, wherein the coating is formed on the side surface of the vane on the suction chamber side as the one side surface.   The film is formed on the tip surface and the one side surface by performing a film forming process of laminating the film on the two vanes stacked with the side surfaces facing each other. The rotary compressor according to claim 1 or 2. The vane includes a base material made of tool steel,
The coating is
A first layer laminated on the surface of the base material and comprising a single layer of chromium;
A second layer laminated on the first layer and made of an alloy layer of chromium and tungsten carbide;
A third layer comprising a metal-containing amorphous carbon layer laminated on the second layer and containing at least one of tungsten and tungsten carbide;
A fourth layer comprising an amorphous carbon layer that is laminated on the third layer and does not contain metal and contains carbon and hydrogen;
Have
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. Rotary compressor.   A refrigeration cycle apparatus comprising the rotary compressor according to any one of claims 1 to 4, a condenser, an expansion device, and an evaporator.

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