JP2011064180A - Refrigerant compressor and refrigerating cycle device - Google Patents

Abstract

An object of the present invention is to prevent chipping or peeling of a hard film provided on a sliding member and to improve the initial conformability of the film to a mating member with which the sliding member is in sliding contact.
In a refrigerant compressor that is provided in a refrigeration cycle and has a compression mechanism having a sliding member 15b and compresses a refrigerant, the sliding member 15b includes a base material 24 formed of a metal material, And a film 29 harder than the base material 24 formed on the surface of the base material 24. The surface roughness of the base material 24 is such that the maximum peak height “Rp” is 0.5 μm or less, and the arithmetic average roughness “Ra” is set to 0.2 μm or less, and the initial wear height “Rpk” is set to be smaller than the oil sump depth “Rvk”.
[Selection] Figure 4

Description

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

  Refrigerant compressors, engines, etc. use sliding members that slide while contacting the mating member, and these sliding members are coated with a hard coating to improve wear resistance. Are known.

  The following Patent Document 1 discloses a sliding member coated with an amorphous hard carbon film. The surface roughness of the amorphous hard carbon film is 10-point average roughness “Rz” of 0.7 μm or less. In addition, the initial wear height “Rpk” is set to 0.07 to 0.14 μm.

Japanese Patent Laid-Open No. 2007-232026

  In the sliding member described in Patent Document 1, since the surface roughness of the amorphous hard carbon film has “Rz” of 0.7 μm or less, the accuracy required for finish polishing is inevitably increased. Polishing takes time and product costs are high.

  In the sliding member described in Patent Document 1, no measures are taken to prevent chipping or peeling of the amorphous hard carbon film.

  The present invention has been made to solve such problems, and its purpose is to prevent chipping or peeling of a hard film provided on the sliding member, and to a counterpart member on which the sliding member is in sliding contact. This is to improve the initial conformability of the film.

  A first feature according to an embodiment of the present invention is a refrigerant compressor that is provided in a refrigeration cycle and has a compression mechanism having a sliding member and compresses a refrigerant, wherein the sliding member is a metal It has a base material formed of a material and a film harder than the base material formed on the surface of the base material. The surface roughness of the base material has a maximum peak height “Rp” of 0.5 μm or less. The arithmetic average roughness “Ra” is set to 0.2 μm or less, and the initial wear height “Rpk” is set to be smaller than the oil sump depth “Rvk”.

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

  According to the present invention, it is possible to prevent the hard film provided on the sliding member from being chipped or peeled off, and to improve the initial conformability of the film to the mating member with which the sliding member is in sliding contact.

It is a schematic diagram which shows the refrigerating cycle apparatus in the 1st Embodiment of this invention. It is a vertical front view which shows the internal structure of a refrigerant compressor. It is a perspective view which shows the cylinder, roller, and vane which comprise a compression mechanism part. It is sectional drawing which shows the front-end | tip part of a vane. It is a measurement figure of the surface roughness of the base material which carried out the barrel grinding | polishing. It is a measurement figure of the surface roughness of the base material before performing barrel polishing. It is a graph which shows the relationship between the surface roughness of a base material, and the amount of wear of a roller.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a refrigeration cycle apparatus 1 including a refrigerant compressor.

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

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

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

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

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

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

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

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

  The roller 14b is fitted in the eccentric portion 10b of the rotating shaft 10, and rotates in the cylinder chamber 12b as the rotating shaft 10 rotates. The roller 14 a is fitted to the eccentric portion 10 a of the rotating shaft 10 and rotates in the cylinder chamber 12 a as the rotating shaft 10 rotates. The rollers 14a and 14b are made of flake graphite cast iron containing molybdenum, nickel, and chromium.

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

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

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

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

  FIG. 4 is a cross-sectional view showing a part of the tip side of the vane 15b. The vane 15a has the same structure. The vane 15b uses a base material 24 formed by cold forging chrome molybdenum steel, which is a metal material, barrel-polishing the base material 24, and the surface roughness of the base material 24 is set to a maximum peak height “ Rp ”is 0.5 μm or less, arithmetic average roughness“ Ra ”is 0.2 μm or less, and initial wear height“ Rpk ”is smaller than oil sump depth“ Rvk ”.

  FIG. 5 is a measurement diagram of the surface roughness of the base material 24 subjected to barrel polishing. FIG. 6 is a measurement diagram of the surface roughness of the substrate 24 before barrel polishing. According to the measurement diagrams of FIGS. 5 and 6, the protruding peak portion is removed by performing barrel polishing, the valley portion is not easily removed by barrel polishing, and the initial wear height “Rpk” is the oil sump depth “ It was found to be smaller than Rvk ”.

  The base material 24 is subjected to surface hardening treatment by carburizing and quenching, and after the surface hardness is set to 650 with Vickers hardness, barrel polishing is performed. When the surface hardening treatment is performed after barrel polishing, the surface roughness of the barrel polished surface may deteriorate again. This surface hardening treatment does not mean that only the surface of the base material 24 is hardened, but means that at least the surface of the base material 24 is hardened, and includes the case where the whole base material 24 is hardened.

  On the surface of the base material 24 subjected to barrel polishing after the surface hardening treatment, a first layer 25 composed of a single layer of chromium (Cr) and a second layer composed of an alloy layer of chromium and tungsten carbide (WC). A layer 26, a third layer 27 made of an amorphous carbon layer containing tungsten (W), and a fourth layer 28 made of an amorphous carbon layer containing no carbon and containing hydrogen are sequentially laminated. Thus, a film 29 harder than the base material 24 is formed. Note that the third layer 27 may be an amorphous carbon layer containing tungsten carbide instead of tungsten, or an amorphous carbon layer containing both tungsten and tungsten carbide.

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

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

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

  FIG. 7 is a graph showing the results of measuring the wear amount of the roller 14b (14a) when the refrigerant compressor 2 is operated with the vane 15b (15a) slidingly contacted with the roller 14b (14a). The horizontal axis of this graph represents the maximum peak height “Rp” and the arithmetic average roughness “Ra”. The maximum peak height “Rp” is 0.5 μm or less, and the arithmetic average roughness “Ra”. It has been found that the wear amount of the roller 14b can be kept low if is less than 0.2 μm. In this measurement, various vanes and rollers manufactured using base materials 24 having different surface roughnesses are attached to the rotary compression mechanism 9 of the refrigerant compressor 2, and the liquid refrigerant is forcibly interrupted to the rotary compression mechanism 9. The suction was repeated repeatedly and the vane was struck violently against the roller.

  In the present embodiment, the case where the film 29 is formed only on the portion of the vane 15b (15a) that is in sliding contact with the roller 14b (14a) as the mating member has been described as an example. You may form in the perimeter of the vane 15b (15a).

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

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

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

  Further, since the fourth layer 28 located on the outermost side of the film 29 is an amorphous carbon layer containing no carbon and containing carbon and hydrogen, the amorphous carbon layer containing metal is provided on the outermost side. In addition, the hardness can be increased, and the wear resistance of the vane 15b can be improved.

  Regarding the surface roughness of the base material 24 constituting the vanes 15b and 15a, the maximum peak height “Rp” is set to 0.5 μm or less and the arithmetic average roughness “Ra” is set to 0.2 μm or less by barrel polishing. Thereby, the real contact area of the base material 24 can be expanded. For this reason, when the film 29 is formed on the surface of the base material 24, stress concentration between the base material 24 and the film 29 can be suppressed, and chipping or peeling of the film 29 caused by the stress concentration can be prevented. can do.

  Further, by removing the crests on the surface of the substrate 24 by barrel polishing, the crests generated on the surface of the coating 29 when the coating 29 is formed on the surface of the substrate 24 are reduced, and the coating 29 of the vane 15b is reduced. The initial conformability of the sliding contact portion between the roller 14b and the roller 14b is improved.

  Therefore, the sliding contact between the rollers 14b and 14a and the vanes 15b and 15a is improved by improving the initial conformability at the sliding contact portion between the coating film 29 of the vanes 15b and 15a and the rollers 14b and 14a, and preventing the chipping and peeling of the coating film 29. Wear of the part can be suppressed, and the rotary compression mechanism part 9 having durability and reliability can be obtained.

  In barrel polishing, the valley portion remains without being removed. Therefore, when the coating 29 is formed, a recess corresponding to the valley of the base material 24 is formed on the surface of the coating 29. For this reason, the oil reservoir effect of the lubricating oil can be obtained by this concave portion, and the lubricating performance at the sliding contact portion between the vanes 15b and 15a and the rollers 14b and 14a can be enhanced.

2 refrigerant compressor, 4 outdoor heat exchanger (condenser, evaporator), 5 expansion device, 6 indoor heat exchanger (evaporator, condenser), 9 rotary compression mechanism (compression mechanism), 14a, 14b roller (Counter member), 15a, 15b Vane (sliding member), 24 base material, 25 first layer, 26 second layer, 27 third layer, 28 fourth layer, 29 coating

Claims (5)

In the refrigerant compressor that is provided in the refrigeration cycle and compresses the refrigerant by having a compression mechanism portion having a sliding member,
The sliding member has a base material formed of a metal material and a film harder than the base material formed on the surface of the base material,
As for the surface roughness of the base material, the maximum peak height “Rp” is 0.5 μm or less, the arithmetic average roughness “Ra” is 0.2 μm or less, and the initial wear height “Rpk” is the oil sump depth. It is set smaller than “Rvk”,
A refrigerant compressor characterized by that.   The refrigerant compressor according to claim 1, wherein the surface roughness of the base material is obtained by barrel-polishing the base material.   The refrigerant compressor according to claim 1, wherein the coating is formed on at least a portion of the sliding member that is in sliding contact with the mating member. The coating includes a first layer made of a single layer of chromium, a second layer made of an alloy layer of chromium and tungsten carbide, and a metal-containing amorphous carbon layer containing at least one of tungsten and tungsten carbide. A third layer and a fourth layer made of an amorphous carbon layer containing carbon and hydrogen without containing a metal are sequentially laminated on the surface of the base material,
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,
The refrigerant compressor according to any one of claims 1 to 3, wherein the refrigerant compressor is provided.   A refrigeration cycle apparatus comprising the refrigerant compressor according to any one of claims 1 to 4, a condenser, an expansion device, and an evaporator.

Images