JP6977964B2 - Compressor and refrigeration cycle equipment - Google Patents

Description

Embodiments of the present invention relate to a compressor that sucks in and discharges working fluid, and a refrigeration cycle device.

For example, in a refrigerating cycle device such as an air conditioner, a compressor such as a refrigerant compressor having a compression mechanism unit that sucks in and discharges a refrigerant as a working fluid is used. In order to improve the efficiency of such a compressor, it is important to reduce the friction loss of the sliding portion and reduce the leakage loss of the working fluid from the gap of the sealing surface. Although the amount of leakage of the working fluid can be reduced by reducing the gap between the sealing surfaces in the compression mechanism portion, high accuracy is required for the component size or the assembly size, which makes it difficult to manufacture the compressor.

Patent Document 1 describes shots on each sliding surface and sealing surface in a compression mechanism that compresses a working fluid composed of a roller, an upper bearing (main bearing), a lower bearing (secondary bearing), a blade, and a cylinder. It is disclosed that a minute recess is provided by the above. Lubricating oil supplied to the compression mechanism portion is accumulated and held in the concave portion, and an oil film is formed on the sliding surface and the sealing surface, so that the effect of improving the sealing property and the effect of reducing the sliding resistance can be obtained. However, on poorly lubricated sliding surfaces, the effect of oil pooling in the recesses is not fully exhibited, and the lubricating oil is removed from the sliding surface and sealing surface by the working fluid to reduce it, resulting in an effect of improving sealing performance. There was a possibility that the effect of reducing the sliding resistance could not be sufficiently obtained.

Japanese Unexamined Patent Publication No. 2004-316522

The problem to be solved by the present invention is compression that can reduce the amount of leakage of the working fluid by reducing the friction loss of the sliding surface in the compression mechanism portion and improving the sealing property without excessively increasing the processing accuracy and the assembly accuracy. The present invention provides a machine and a refrigerating cycle device using the compressor.

The compressor of the embodiment has a compression mechanism portion that sucks in and discharges the working fluid, and is provided with a polymer brush on at least one of the sliding surface or the sealing surface of the compression mechanism portion.

The schematic block diagram which showed an example of the refrigerating cycle apparatus of 1st Embodiment. The II-II sectional view of the compression mechanism part in the refrigeration cycle apparatus of FIG. The perspective view which showed the blade of the compression mechanism part of 1st Embodiment. FIG. 3 is a sectional view taken along line III-III of the blade of FIG. The figure which showed the relationship between the rotation speed and compression efficiency in Examples 1 and 2 and Comparative Example 1. The two-layer separation temperature diagram in Experimental Example 1.

The definitions of the following terms apply throughout the specification and claims.
The “sliding surface” means a surface that slides in contact with each other in a plurality of parts constituting the compression mechanism portion.
The "sealing surface" is a surface of a plurality of parts constituting the compression mechanism that are faced to each other in a state of being in contact with each other or slightly separated from each other so as to suppress leakage of the working fluid in the compression mechanism. means. The distance between the sealing surfaces facing each other is preferably 0.05 mm or less, more preferably 0.02 mm or less.
"~" Indicating a numerical range means that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.

The compressor of the embodiment has a compression mechanism portion that sucks in and discharges the working fluid, and a polymer brush is provided on at least one of the sliding surface or the sealing surface of the compression mechanism portion. That is, the polymer brush is provided on both the sliding surface and / or the sealing surface of the compression mechanism portion. The compressor may have a compression mechanism portion that sucks in and discharges the working fluid, and adopts a known embodiment without limitation except that a polymer brush is provided on at least one of the sliding surface or the sealing surface of the compression mechanism portion. can.
Further, the refrigeration cycle device of the embodiment includes a compressor, a radiator, an expansion device, and a heat absorber, and a known embodiment can be adopted except that the compressor has the above-mentioned characteristics.

Hereinafter, an example of the compressor and the refrigeration cycle apparatus of the embodiment will be described.
As shown in FIG. 1, the refrigerating cycle device 1 of the present embodiment includes a compressor 2, a condenser 3 which is a radiator connected to the compressor 2, and an expansion device 4 connected to the condenser 3. It includes an evaporator 5 as a heat absorber connected between the expansion device 4 and the compressor 2.

The compressor 2 is a so-called rotary type compressor, which takes in a low-pressure gas refrigerant as a working fluid and compresses it to obtain a high-temperature, high-pressure gas refrigerant. The compressor is not limited to the rotary type, and may be a scroll type, a reciprocating type, a swash plate type, or the like. The specific configuration of the compressor 2 will be described later.
The condenser 3 dissipates heat from a high-temperature, high-pressure gas refrigerant sent from the compressor 2 to form a high-pressure liquid refrigerant.

The expansion device 4 lowers the pressure of the high-pressure liquid refrigerant sent from the condenser 3 to make a low-temperature, low-pressure liquid refrigerant.
The evaporator 5 vaporizes the low-temperature, low-pressure liquid refrigerant sent from the expansion device 4, and turns the low-temperature, low-pressure liquid refrigerant into a low-pressure gas refrigerant. In the evaporator 5, when the low-pressure liquid refrigerant is vaporized, the heat of vaporization is taken from the surroundings and the surroundings are cooled. The low-pressure gaseous refrigerant that has passed through the evaporator 5 is taken into the compressor 2.
As described above, in the refrigerating cycle device 1 of the present embodiment, the refrigerant as the working fluid circulates while changing the phase between the gas refrigerant and the liquid refrigerant.

The compressor 2 includes a compressor main body 11 and an accumulator 12.
The accumulator 12 is a so-called gas-liquid separator. The accumulator 12 is provided between the evaporator 5 and the compressor main body 11. The accumulator 12 is connected to the compressor body 11 through a suction pipe 21. The accumulator 12 supplies only the gas refrigerant out of the gas refrigerant vaporized by the evaporator 5 and the liquid refrigerant not vaporized by the evaporator 5 to the compressor main body 11.

The compressor main body 11 includes a rotating shaft 31, an electric motor unit 32, a compression mechanism unit 33, and a closed container 34 for accommodating the rotating shaft 31, the electric motor unit 32, and the compression mechanism unit 33.
The closed container 34 is formed in a cylindrical shape, and both ends thereof in the O direction of the axis are closed. The lubricant J is housed in the closed container 34. A part of the compression mechanism portion 33 is immersed in the lubricant J.

The lubricant J is not particularly limited, and examples thereof include lubricating oils such as mineral oil, polyol ester oil, polyvinyl ether oil, alkylene glycol oil, and polyalphaolefin oil. The lubricant J is not limited to the lubricating oil, and may be a known ionic liquid or the like. As the lubricant J, one type may be used alone, or two or more types may be used in combination.

The rotating shaft 31 is arranged coaxially along the axis O of the closed container 34. In the following description, the direction along the axis O is simply referred to as the axial direction, the direction orthogonal to the axial direction is referred to as the radial direction, and the direction around the axis O is referred to as the circumferential direction.

The electric motor unit 32 is arranged on the first side in the axial direction in the closed container 34. The compression mechanism portion 33 is arranged on the second side in the axial direction in the closed container 34. In the following description, the motor unit 32 side (first side) along the axial direction is the upper side, and the compression mechanism unit 33 side (second side) is the lower side.

The electric motor unit 32 is a so-called inner rotor type DC brushless motor. Specifically, the motor unit 32 includes a stator 35 and a rotor 36.
The stator 35 is fixed to the inner wall surface of the closed container 34 by shrink fitting or the like.
The rotor 36 is fixed to the upper part of the rotating shaft 31 in a state of being radially spaced inside the stator 35.

The compression mechanism portion 33 separately closes the cylindrical cylinder 41 through which the rotating shaft 31 penetrates and the openings at both ends in the axial direction of the cylinder 41, and the main bearing 42 and the auxiliary bearing that rotatably support the rotating shaft 31. 43 and. The space formed by the cylinder 41, the main bearing 42, and the auxiliary bearing 43 constitutes the cylinder chamber 46 (see FIG. 2).

An eccentric portion 51 that is eccentric in the radial direction with respect to the axis O is formed in a portion of the rotating shaft 31 located in the cylinder chamber 46.
A roller 53 is extrapolated to the eccentric portion 51. The roller 53 is configured to be eccentrically rotatable with respect to the axis O while the outer peripheral surface 53a is in sliding contact with the inner peripheral surface 41a of the cylinder 41 via the lubricating oil film as the rotating shaft 31 rotates.

As shown in FIGS. 1 and 2, a blade groove 54 recessed outward in the radial direction is formed in a part of the cylinder 41 in the circumferential direction. The blade groove 54 is formed over the entire axial direction (height direction) of the cylinder 41. The blade groove 54 communicates with the closed container 34 at the radial outer end.

The blade 55 shown in FIG. 3 is provided in the blade groove 54. The blade 55 is configured to be slidable in the radial direction with respect to the cylinder 41. As shown in FIG. 1, in the blade 55, the back surface 55b, which is the outer end surface in the radial direction, is urged inward in the radial direction by the urging means 57. On the other hand, as shown in FIG. 2, in the blade 55, the tip surface 55a, which is the inner end surface in the radial direction, is in contact with the outer peripheral surface 53a of the roller 53 in the cylinder chamber 46. As a result, the blade 55 is configured to be able to move forward and backward in the cylinder chamber 46 as the roller 53 rotates eccentrically. The cylinder chamber 46 is divided into a suction chamber 46a and a compression chamber 46b by the roller 53 and the blade 55.
In a plan view seen from the axial direction, the tip surface 55a of the blade 55 has an arc shape that is convex inward in the radial direction.

Lubricating oil J is interposed between the blade 55 and the inner surfaces 54a and 54b of the blade groove 54, between the blade 55 and the lower surface 42a of the main bearing 42, and between the blade 55 and the upper surface 43a of the auxiliary bearing 43. ..

In the cylinder 41, a suction hole that penetrates the cylinder 41 in the radial direction is located in front of the roller 53 in the rotation direction (see the arrow in FIG. 2) (on the left side of the blade groove 54 in FIG. 2) with respect to the blade groove 54. 56 is formed. The radial outer end of the suction hole 56 is connected to the suction pipe 21 (see FIG. 1). On the other hand, the radial inner end of the suction hole 56 is open in the suction chamber 46a of the cylinder chamber 46.
A discharge groove 58 is formed in a portion of the cylinder 41 located on the front side of the blade groove 54 (on the right side of the blade groove 54 in FIG. 2) along the rotation direction of the roller 53. The discharge groove 58 is formed in a semicircular shape in a plan view seen from the axial direction. The discharge groove 58 is open at least on the upper surface of the cylinder 41.

As shown in FIG. 1, the main bearing 42 closes the upper end opening of the cylinder 41. The main bearing 42 rotatably supports a portion of the rotating shaft 31 located above the cylinder 41. Specifically, the main bearing 42 includes a tubular portion 61 through which the rotating shaft 31 is inserted, and a flange portion 62 projecting outward from the lower end portion of the tubular portion 61 in the radial direction.

As shown in FIGS. 1 and 2, a discharge hole 64 (see FIG. 2) that penetrates the flange portion 62 in the axial direction is formed in a part of the flange portion 62 in the circumferential direction. The discharge hole 64 communicates with the cylinder chamber 46 through the discharge groove 58. The flange portion 62 is provided with a discharge valve mechanism (not shown) that opens and closes the discharge hole 64 as the pressure inside the cylinder chamber 46 (compression chamber 46b) rises and discharges the refrigerant to the outside of the cylinder chamber 46.

As shown in FIG. 1, the main bearing 42 is provided with a muffler 65 that covers the main bearing 42 from above. The muffler 65 is formed with a communication hole 66 that communicates inside and outside the muffler 65. The high-temperature, high-pressure gas refrigerant discharged through the discharge hole 64 is discharged into the closed container 34 through the communication hole 66.

The auxiliary bearing 43 closes the lower end opening of the cylinder 41. The auxiliary bearing 43 rotatably supports a portion of the rotating shaft 31 located below the cylinder 41. Specifically, the auxiliary bearing 43 includes a tubular portion 71 through which the rotating shaft 31 is inserted, and a flange portion 72 projecting outward from the upper end portion of the tubular portion 71 in the radial direction.

The material of each member in the compression mechanism portion 33 is not particularly limited. The material of the cylinder 41, the main bearing 42, and the auxiliary bearing 43 is, for example, gray cast iron such as FC250, and the material of the roller 53 is, for example, a special alloy cast iron (monikuro cast iron) in which Mo, Ni, Cr, etc. are added to the gray cast iron of FC250. ). As the material of the blade 55, for example, a SUS440C formed by gas nitriding treatment can be used.

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

Specifically, in the cylinder chamber 46, the working fluid (gas refrigerant) is sucked into the suction chamber 46a through the suction hole 56, and the gas refrigerant previously sucked from the suction hole 56 is compressed in the compression chamber 46b. To. The compressed gaseous refrigerant is discharged to the outside of the cylinder chamber 46 (inside the muffler 65) through the discharge hole 64 of the main bearing 42, and then discharged into the closed container 34 through the communication hole 66 of the muffler 65. The gaseous refrigerant discharged into the closed container 34 is sent to the condenser 3.

The working fluid is not particularly limited, and examples thereof include a chlorine-free hydrocarbon-based refrigerant, carbon dioxide, a saturated fluorinated hydrocarbon-based refrigerant, an unsaturated fluorinated hydrocarbon-based refrigerant, a fluorinated ether-based refrigerant, and the like. .. As the working fluid, one type may be used alone, or two or more types may be used in combination.

In the compression mechanism portion 33 of the compressor 2, the tip surface 55a of the blade 55, the side surfaces 55c and 55d on both sides, the upper end surface 55e and the lower end surface 55f, the outer peripheral surface 53a of the roller 53, the inner peripheral surface 53b, the upper end surface and the lower end surface, The inner surfaces 54a and 54b of the blade groove 54, the lower surface 42a and the inner peripheral surface of the main bearing 42, the upper surface 43a and the inner peripheral surface of the auxiliary bearing 43, the outer peripheral surface of the rotating shaft 31, and the like are sliding surfaces.
Further, the side surfaces 55c and 55d on both sides of the blade 55, the upper end surface 55e and the lower end surface 55f, the upper end surface and the lower end surface of the roller 53, the lower surface 42a of the main bearing 42, the upper surface 43a of the auxiliary bearing 43, and the like are also sealing surfaces. The inner peripheral surface 41a and the like of the cylinder 41 are sealing surfaces.

A polymer brush is provided on at least one of the sliding surface or the sealing surface of the compression mechanism portion 33. For example, as shown in FIG. 4, a polymer brush 82 is provided on the base material 81 of the blade 55 on the front end surface 55a, the side surfaces 55c, 55d on both sides, the upper end surface 55e, and the lower end surface 55f of the blade 55.

The polymer brush may be provided only on the sliding surface, may be provided only on the sealing surface, or may be provided on both the sliding surface and the sealing surface. When the polymer brush is provided on the sliding surface, the polymer brush may be provided on all of the plurality of sliding surfaces, or the polymer brush may be provided only on a specific sliding surface. Further, a polymer brush may be provided on the entire sliding surface (entire surface), or a polymer brush may be provided on a part of the sliding surface. When the polymer brush is provided on the sealing surface, the polymer brush may be provided on all of a plurality of sealing surfaces, or the polymer brush may be provided only on a specific sealing surface. Further, a polymer brush may be provided on the entire sealing surface (entire surface), or a polymer brush may be provided on a part of the sealing surface.
The polymer brush may be provided on a swing bush (not shown) or the like that freely supports the advancement and retreat of the blade in a swing type rotary compressor in which the blade and the roller have an integrated structure.

The polymer brush is formed of a plurality of polymer chains and exhibits excellent mechanical properties such as high compression resistance and low frictional resistance. Therefore, by providing the polymer brush on the sliding surface, the friction loss of the sliding surface is reduced. Further, by providing the polymer brush on the sealing surface, the lubricant is easily held by the polymer brush, and the sealing property is improved.

Examples of the polymer forming the polymer brush include poly (methyl methacrylate) (PMMA), poly (lauryl methacrylate) (PLMA), and poly (N, N-diethyl-N- (2-methacryloylethyl) -N-methylammonium. -Bis (trifluoromethylsulfonyl) imide) (PDEMM-TFSI) and the like can be mentioned. The polymer forming the polymer brush may be one kind or two or more kinds.

As the embodiment for grafting each polymer in the polymer brush, a known embodiment can be adopted.
It is preferred that the polymer forming the polymer brush has reactive functional groups for bonding to the substrate and is grafted via a bond using the functional groups. Examples of the reactive functional group include a hydrolyzable silyl group such as a dialkoxysilyl group and a trialkoxysilyl group.

In the polymer brush, it is preferable that the polymer is grafted via an oxide containing silicon. As a result, the polymer brush is formed more effectively, and it becomes easy to effectively exert the tribology and toughness of the polymer brush. Therefore, the effect of reducing the friction loss due to low friction and the effect of reducing the leakage loss due to the improvement of the sealing property can be easily obtained, and the efficiency of the compressor is improved.

More specifically, on a specific part of the sliding surface and the sealing surface, the surface of the substrate is coated with an oxide containing silicon, and the polymer having a hydrolyzable silyl group at the end is the oxide containing the silicon. It is preferably bonded by binding with a siloxane bond. For example, a coupling agent having a polymerization initiator such as a bromo group is coupled to an oxide containing silicon coated on the surface of a substrate, and then atom transfer radical polymerization (ATRP) is performed in a solution. Can form a polymer brush with.

Examples of the oxide containing silicon include tetramethoxysilane, tetraethoxysilane, ethoxytrimethoxysilane, dimethoxydiethoxysilane, and methoxytriethoxysilane. As the oxide containing silicon, one type may be used alone, or two or more types may be used in combination.

Examples of the coupling agent having a polymerization initiating group include (3-trimethoxysilyl) propyl-2-bromo-2-methylpropionate. As the coupling agent having a polymerization initiating group, one kind may be used alone, or two or more kinds may be used in combination.

The polymer brush preferably has a crosslinked structure. Since the polymer brush has a crosslinked structure, the tribology and toughness of the polymer brush can be effectively exhibited, the effect of reducing friction loss due to low friction and the effect of reducing leakage loss due to improved sealing performance are improved, and the compressor Efficiency improvement is further enhanced.

Examples of the cross-linking group for forming the cross-linked structure include an azide group, a halogen group (preferably a bromo group) and the like. The polymer may have a cross-linking group in the main chain, and if it has a branched chain, it may have a cross-linked group in the branched chain. An unreacted reactive group generated in the main chain when forming the branched chain may be used as a cross-linking group, and a reactive group remaining at the end of the branched chain when the branched chain is formed by living radical polymerization is used as a cross-linking group. May be.

The cross-linked structure may be a physical cross-link or a chemical cross-link. The introduction of physical cross-linking and chemical cross-linking may be performed during polymerization (in-situ cross-linking) when forming a polymer brush, or may be performed after polymerization.
For example, when chemical cross-linking is introduced by in-situ cross-linking, an appropriate amount of a bifunctional monomer such as a divinyl monomer (ethylene glycol dimethacrylate, etc.) may be added in addition to the monomer (monofunctional) at the time of polymerization. The amount of the bifunctional monomer added may be appropriately set, and may be, for example, 1 mol% with respect to the total amount of the monomers.

A polymer brush having a crosslinked structure does not dissolve in a good solvent (for example, o-dichlorobenzene) even if it is cut out from the surface of the substrate. This confirms that the polymer is sufficiently crosslinked. Further, when the swelling degree of the polymer brush is measured by the AFM colloid probe method in a good solvent, the swelling degree is lower than that in the non-crosslinked state, so that it can be confirmed that the crosslinks are sufficiently formed.

The graft density of the polymer forming the polymer brush is preferably set so that the polymer brush exhibits high lubricity. The graft density can be appropriately set depending on the type of polymer used, the type of solvent, and the like.

When the polymer is PMMA, the graft density is preferably 0.1 chain / nm ² or more, more preferably 0.15 chain / nm ² or more, further preferably 0.2 chain / nm ² or more, and 0.3 chain / nm. nm ² or more is particularly preferable, 0.4 chain / nm ² or more is extremely preferable, and 0.45 chain / nm ² or more is most preferable.

When the polymer is PLMA, the graft density is ^{preferably 0.04 chain / nm 2} or more, more preferably 0.06 chain / nm ² or more, further preferably 0.08 / nm ² or more, and 0.12 chain / nm. ² or more is particularly preferable, 0.16 chain / nm ² or more is extremely preferable, and 0.18 chain / nm ² or more is most preferable.

When the polymer is PDEMM-TFSI, the graft density is ^{preferably 0.02 chain / nm 2} or more, more preferably 0.03 chain / nm ² or more, still more preferably 0.04 chain / nm ² or more, 0.06. Chain / nm ² or more is particularly preferable, 0.08 chain / nm ² or more is extremely preferable, and 0.09 chain / nm ² or more is most preferable.

The polymer graft density can be measured according to known methods. For example, it can be measured according to the method described in Macromolecules, 31, 5934-5936 (1998), Macromolecules, 33, 5608-5612 (2000), Macromolecules, 38, 2137-2142 (2005) and the like.
Specifically, the graft density σ (chain / nm ² ) is obtained by measuring the graft amount (W), which is the amount of the polymer forming the polymer brush, and the number average molecular weight (Mn) of the polymer (graft chain). It can be obtained from the equation (1).
σ (chain / nm ² ) = W (g / nm ² ) / Mn × (Avogadro's number) ・ ・ ・ (1)

The amount of graft (W) is determined by measuring the dry thickness of the polymer brush by the ellipsometry method when the surface of the substrate on which the polymer brush is formed is flat, and using the measured value and bulk density, per unit area. The amount of graft can be calculated. When the material of the substrate surface on which the polymer brush is formed is silica, the graft amount (W) can be measured by infrared absorption spectroscopy (IR), heat weight loss measurement (TG), elemental analysis measurement, etc. can.

Specifically, the graft density σ is, for example, the slope of a graph plotting the thickness of the polymer brush in a dry state and the Mn of the polymer (see, for example, Japanese Patent Application Laid-Open No. 11-263819), and the amount of the polymer graft of the polymer brush. And Mn of the polymer can be obtained from the slope of the plotted graph.

The ratio of the occupied area of the polymer forming the polymer brush to the area of the region where the polymer brush is formed on the sliding surface and the sealing surface (the ratio of the occupied area of the polymer to the cross-sectional area of the cross section orthogonal to the thickness direction of the polymer brush). ) Σ ^* is preferably 10% or more, more preferably 15% or more, still more preferably 20% or more. When the occupied area ratio σ ^* is equal to or higher than the lower limit, the tribological characteristics of the polymer brush are improved and the resiliency is achieved, so that the polymer brush has excellent durability. The compressor can be applied to various usage environments and applications.

The surface occupancy rate σ ^* means the ratio of the graft point (the first monomer of the polymer) in the region where the polymer brush is formed on the sliding surface and the sealing surface. ^{In the polymer brush, the surface occupancy rate σ *} is 100% in the state where each polymer is tightly packed, that is, in the state where the polymer cannot be grafted any more.
The surface occupancy rate σ ^* is calculated by obtaining the cross-sectional area of the cross section orthogonal to the thickness direction of the polymer brush from the repeating unit length in the stretched form of the polymer and the bulk density of the polymer, and multiplying this by the graft density σ. can.

The Mn of the polymer forming the polymer brush can be set to exhibit the desired lubricity, preferably 500 to 10,000,000, more preferably 100,000 to 10,000,000.
The molecular weight distribution index (Mw / Mn) can be set so as to show the desired lubricity, and is preferably 1.5 or less, more preferably 1.01 to 1.5.

The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polymer forming the polymer brush are hydrogen fluoride when the substrate is silica or when the substrate surface is silica-coated and the polymer is grafted. After cutting out the polymer (graft chain) from the graft point by acid treatment, it can be measured by gel permeation chromatography (GPC) method.

The Mn and Mw of the polymer forming the polymer brush are substantially equal to the Mn and Mw of the free polymer obtained by the polymerization under the same conditions as the polymerization at the time of forming the polymer brush. For example, by adding a release initiator to the polymerization solution for forming a polymer brush, a free polymer having Mn and Mw equivalent to that of the polymer forming the polymer brush can be obtained. The Mn and Mw of this free polymer may be measured by the GPC method and used as the Mn and Mw of the polymer forming the polymer brush.
In the GPC method, a calibration method using a standard sample in which a polymer having a known molecular weight is monodispersed, and an absolute molecular weight evaluation using a multi-angle light scattering detector are performed.

The average length of the polymer forming the polymer brush can be set to show the desired lubricity, preferably 0.5 μm or more, more preferably 0.7 μm or more, still more preferably 0.8 μm or more, and particularly preferably 1 μm or more. preferable. When the average length of the polymer is not less than the lower limit, the tribological characteristics of the polymer brush are improved and the resiliency is achieved, so that the polymer brush has excellent durability. The compressor can be applied to various usage environments and applications.
The upper limit of the average length of the polymer can be appropriately set within a range that does not impair the function of the compressor, and can be, for example, 5 μm.
The average length of the molecular chain of the polymer can be obtained from, for example, Mn and Mw / Mn of the polymer.

The polymer brush shall be a thick film thick polymer brush formed of a polymer having an average length of molecular chains of 0.5 μm or more and having an occupied area ratio σ ^{* of the polymer on the sliding surface and the sealing surface of 10% or more.} Is particularly preferable.

The polymer brush is preferably swollen with a lubricant that lubricates the compression mechanism. When the polymer brush is in a swollen state, sliding characteristics such as flexibility, toughness, and low friction are improved, and the effect of reducing friction loss on the sliding surface and the effect of improving the sealing property on the sealing surface are further enhanced. Further, by using a lubricant that lubricates the compression mechanism portion, the lubricant is stably supplied to the polymer brush, and it is easy to maintain the swollen state of the polymer brush.

The lubricant that swells the polymer brush is always in phase with the working fluid at -10 ° C to 60 ° C when mixed so that the ratio of the lubricant to the total mass of the working fluid and the lubricant is 60% by mass or more. Soluble lubricants are preferred. Thereby, by mixing the lubricant with the working fluid, the lubricant can be stably supplied to the polymer brush by utilizing the working medium. Therefore, it is possible to improve the efficiency of the compressor and ensure long-term reliability in a wide range of usage environments.

The combination of such a working fluid and the lubricant comprises a chlorine-free hydrocarbon-based refrigerant, carbon dioxide, a saturated fluorinated hydrocarbon-based refrigerant, an unsaturated fluorinated hydrocarbon-based refrigerant, and a fluorinated ether-based refrigerant. A combination of at least one working fluid selected from the group and at least one lubricant selected from the group consisting of mineral oils, polyol ester oils, polyvinyl ether oils, alkylene glycol oils and polyalphaolefin oils is preferred. As a result, a polymer brush having excellent lubricity and chemical stability and excellent long-term reliability can be easily formed.

Specific examples of the working fluid include propane, propylene, normal butane, 2-methylbutane, isobutane, carbon dioxide gas for refrigerant (R744), HFC23, HFC32, HFC125, HFC134a, HFC143a, HFC236fa, HFC410A, HFO1225ye, HFO1233zd, HFO1233yd, HFO1233yd. , HFO1234ze, HFO1234ye, HFO1243zf, HFE245mc, HFE143m and the like.

Specific examples of the lubricant include a polyol ester oil (POE) having a kinematic viscosity at 40 ° C. of ^{74 mm 2} / s and a kinematic viscosity of 100 ° C. of 8.7 mm ^{2 / s, and a kinematic viscosity at 40 ° C. of 68 mm 2} / s. , polyvinyl ether oil kinematic viscosity of 100 ° C. is ^8mm 2 / s (PVE), polyalkylene glycol oils kinematic viscosity of 40 ° C. kinematic viscosity 105mm ² / s, 100 ℃ is 20mm ² / s (PAG) , Mineral oil having a kinematic viscosity at 40 ° C. of 10 mm ² / s and a kinematic viscosity at 100 ° C. of 2.3 mm ² / s.

When the polymer brush is inflated with a lubricant, the combination of the polymer and the lubricant forming the polymer brush is preferably a combination of PLMA and a refrigerating machine oil selected from polyol esters and polyvinyl ethers. Since PLMA and these refrigerating machine oils have an excellent affinity, it becomes easy to swell the polymer brush, and the effect of reducing friction loss and the effect of reducing leakage loss by improving the sealing property can be obtained more stably.

When the polymer brush is inflated with a lubricant, PMMA is preferred as the polymer forming the polymer brush in that a non-polar lubricant can be applied. The non-polar lubricant has less adverse effect on the metal material, organic material, etc. used in the compressor, and can be a more reliable compressor.

According to at least one embodiment described above, by providing the polymer brush on at least one of the sliding surface or the sealing surface of the compression mechanism portion, the compression mechanism portion does not excessively increase the processing accuracy and the assembly accuracy. It is possible to reduce the amount of leakage of the working fluid by reducing the friction loss of the sliding surface and improving the sealing property.

Although the embodiments of the present invention have been described, the embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

Hereinafter, the description will be specifically described with reference to Examples, but the description is not limited to the following. In addition, "part" in the following description means "part by mass".
[Example 1]
An example of a method of coating the sliding surface of the blade with an oxide containing silicon will be described. The gas-nitrided blade (SUS440C) of the embodiment shown in FIG. 3 was subjected to a mixed solvent having a mass ratio of acetone and hexane for 30 minutes, then chloroform for 30 minutes, and then 2-propanol for 30 minutes. It was ultrasonically cleaned and treated with a UV ozone cleaner for 30 minutes. The washed blade was immersed in 34.8 parts of ethanol.
Prepare a solution of 0.54 part of tetraethoxysilane (TEOS) and 17.8 parts of ethanol in a sample container with a lid, and prepare a solution of 1.3 parts of 28% ammonia water and 17.8 parts of ethanol in another sample container. And mixed them. The washed blade was added to the mixed solution together with 34.8 parts of ethanol and reacted at room temperature (25 ° C.) for 24 hours. Then, the blade was taken out from the reaction solution and ultrasonically cleaned with ethanol to obtain a silica-coated blade. ..

The serial force coat blade was ultrasonically cleaned with a mixed solvent having a mass ratio of acetone and hexane for 30 minutes, then with chloroform for 30 minutes, then with 2-propanol for 30 minutes, and treated with a UV ozone cleaner for 30 minutes.
Prepare a solution of 0.5 part of (3-trimethoxysilyl) propyl-2-bromo-2-methylpropionate and 22.3 parts of ethanol in a sample container with a lid, and in another sample container, 28% aqueous ammonia 5 A solution of .7 parts and 25.4 parts of ethanol was prepared and mixed. The washed silica-coated blade is immersed in the mixed solution, and a silane coupling reaction is carried out at room temperature (25 ° C.) for 24 hours. Then, the blade is taken out from the reaction solution and ultrasonically washed with ethanol to immobilize the starting group. Got a blade.

In the glove box, in a pressure vessel made of Teflon (registered trademark), 0.00026 parts of ethyl-2-bromo-2-methylpropionate, 26.6 parts of methyl methacrylate (MMA), copper (I) bromide (I) 0. Twelve parts, 0.021 parts of copper (II) bromide, 0.78 parts of 4,4'-dinonyl-2,2'-bipyridyl and 27.5 parts of anisole were added. Next, the initiating group-immobilized blade was placed in a pressure-resistant container, covered, and surface-initiated atom transfer radical polymerization (SI-ATRP) was carried out under the conditions of 600 C and 400 MPa for 4 hours. After completion of the polymerization, the blade was taken out from the polymerization solution and thoroughly washed with tetrahydrofuran (THF) to obtain a blade with a thick film PMMA brush.

The polymerization solution after ^{polymerization,} carried out molecular weight measurements by the 1 H-NMR measurement and GPC method, calculation of Mn and Mw / Mn of free PMMA, Mn is 1.8 × ¹⁰ 6, Mw / Mn 1.14 Met.
In addition, at the time of polymerization, a silicon wafer on which a polymerization initiating group was immobilized by the same method as in the case of a blade was also added to the polymerization solution and used as a reference for film thickness measurement. The dry film thickness of the PMMA brush formed on the silicon wafer was analyzed by an ellipsometry method and found to be 0.80 μm. When the graft density σ and the surface occupancy σ ^* were calculated from the obtained data, the graft density σ was 0.32 chain / nm ² and the surface occupancy σ ^* was 18%.

Using the obtained thick film PMMA brushed blade, a compressor having the same embodiment as the compressor 2 illustrated in FIG. 1 was manufactured. The material of the cylinder 41, the main bearing 42, and the auxiliary bearing 43 was FC250 gray cast iron, and the material of the roller 53 was a special alloy cast iron (monikuro cast iron) in which Mo, Ni, Cr, etc. were added to FC250 gray cast iron.

[Example 2]
A starting group-immobilized blade was obtained in the same manner as in Example 1.
In the glove box, in a pressure-resistant container made of Teflon (registered trademark), 0.00026 part of ethyl-2-bromo-2-methylpropionate, lauryl methacrylate (SLMA, Blemmer SLMA-S manufactured by Nichiyu Co., Ltd.) 36. Add 1 part, 0.21 part of copper (I) bromide, 0.014 part of copper (II) bromide, 1.2 parts of 4,4'-dinonyl-2,2'-bipyridyl, and 37.5 parts of anisole. did. Next, the starting group immobilization blade was placed in a pressure-resistant container, covered, and subjected to SI-ATRP under the conditions of 600 C and 400 MPa for 2 hours. After completion of the polymerization, the blade was taken out from the polymerization solution and washed thoroughly with THF to obtain a blade with a thick film PLMA brush.

The polymerization solution after ^{polymerization,} carried out molecular weight measurements by the 1 H-NMR measurement and GPC method, calculation of Mn and Mw / Mn of free PLMA, Mn is 4.6 × ¹⁰ 6, Mw / Mn 1.23 Met.
Moreover, when the dry film thickness of the PLMA brush formed on the silicon wafer was analyzed by the same method as in Example 1, it was 1.02 μm. When the graft density σ and the surface occupancy rate σ ^* were calculated from the obtained data, the graft density σ was 0.12 chains / nm ² and the surface occupancy rate σ ^* was 22%.

A compressor was produced in the same manner as in Example 1 except that a blade with a thick film PLMA brush was used instead of the blade with a thick film PMMA brush.

[Comparative Example 1]
A compressor was produced in the same manner as in Example 1 except that a blade that did not form a polymer brush was used.

[ ^{1 1} H-NMR measurement]
^{1 In the} H-NMR measurement, a Fourier transform nuclear magnetic resonance apparatus FT-NMR (“JNM-ECA600” or “ECA400” manufactured by JEOL RESONANCE Co., Ltd.) was used. Deuterated chloroform (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the deuterated solvent.

[Gel Permeation Chromatography (GPC)]
In the molecular weight measurement by the GPC method, "Shodex GPC-101" manufactured by Showa Denko KK was used as the molecular weight measuring device, and two "Shodex KF-806L" manufactured by Showa Denko KK) were connected in series as the column. THF was used as the eluent. The measurement was performed at 40 ° C. and the flow rate was 0.8 mL / min. Mn and Mw / Mn were determined using a PMMA-converted calibration curve obtained by using a calibration sample as PMMA (manufactured by VARIAN) having a known molecular weight.

[Dry film thickness of polymer brush]
A spectroscopic ellipsometer (“M-2000U” manufactured by JA Woolam Japan Co., Ltd.) was used to measure the dry film thickness of the polymer brush. As a light source, a deuterium lamp and a quartz tungsten halogen (QTH) lamp were used.

[Compressor efficiency evaluation]
HFC32 was used as the working fluid, polyol ester oil was used as the lubricant, and the efficiencies were compared based on the compressor of Comparative Example 1 to which the polymer brush was not applied under ASHRAE (American Power Heating, Refrigerating and Air-Conditioning Society) conditions. The results are shown in FIG.

As shown in FIG. 5, in the compressors of Examples 1 and 2 in which the polymer brushes are provided on the sliding surface and the sealing surface of the blade, the efficiency based on the compressor of Comparative Example 1 to which the polymer brush is not applied is high. It exceeded 100%, and the efficiency was improved especially in the low speed range. It is considered that this is caused by the reduction of the friction loss of the sliding surface around the blade and the reduction of the leakage loss by improving the sealing property.

[Experimental Example 1]
FIG. 6 shows a two-layer separation temperature diagram of HFC410A, which is a refrigerant as a working fluid, and a polyol ester refrigerating machine oil as a lubricant, at -10 ° C to 60 ° C.

As shown in FIG. 6, in the temperature range of -10 ° C to 60 ° C, the working fluid (refrigerant) and the lubricant (refrigerator oil) have a region where the working fluid (refrigerant) and the lubricant (refrigerator oil) are separated into two layers, but with respect to the total mass of the working fluid and the lubricant. When the ratio of the lubricant was 60% by mass or more, it always had compatibility.

1 ... Refrigeration cycle device, 2 ... Compressor, 3 ... Condenser (radiator), 4 ... Expansion device, 5 ... Evaporator (heat absorber), 34 ... Sealed container, 41 ... Cylinder, 42 ... Main bearing (blocking plate) ), 43 ... Auxiliary bearing, 46 ... Cylinder chamber, 53 ... Roller, 55 ... Blade, 81 ... Base material, 82 ... Polymer brush.

Claims (11)

In a rotary compressor having a compression mechanism that sucks in and discharges working fluid,
At least the side surfaces, the upper end surface, the lower end surface, and the facing surfaces thereof on both sides of the blade in the compression mechanism portion are sliding surfaces and sealing surfaces, and a polymer brush is provided on at least a part of the sliding surfaces and sealing surfaces. Has been
The lubricant for lubricating the compression mechanism portion is a compressor having compatibility with the working fluid. The compressor is a swing-type rotary compressor in which a blade and a roller are integrated.
The compressor according to claim 1, wherein the polymer brush is provided on a swing bush that freely supports the advancement and retreat of the blade in the swing type rotary compressor. The compressor according to claim 1 or 2 , wherein the polymer brush is inflated with a lubricant that lubricates the compression mechanism portion. The lubricant always operates at −10 ° C. to 60 ° C. when mixed with the working fluid so that the ratio of the lubricant to the total mass of the working fluid and the lubricant is 60% by mass or more. The compressor according to any one of claims 1 to 3, which has compatibility with a fluid. The working fluid is at least one selected from the group consisting of a hydrocarbon-based refrigerant containing no chlorine, carbon dioxide, a saturated fluorinated hydrocarbon-based refrigerant, an unsaturated fluorinated hydrocarbon-based refrigerant, and a fluorinated ether-based refrigerant. ,
The compressor according to claim 4 , wherein the lubricant is at least one selected from the group consisting of mineral oil, polyol ester oil, polyvinyl ether oil, alkylene glycol oil and polyalphaolefin oil. The polymer brush is formed of a polymer having an average length of a molecular chain of 0.5 μm or more, and the occupied area ratio of the polymer with respect to the area of the region where the polymer brush is formed on the sliding surface and the sealing surface is 10. The compressor according to claim 4 , wherein the thick film thick polymer brush is% or more. The compressor according to claim 6 , wherein the lubricant is a refrigerating machine oil selected from polyol ester and polyvinyl ether, and the polymer forming the polymer brush is poly (lauryl methacrylate). The compressor according to claim 6 , wherein the polymer forming the polymer brush is poly (methyl methacrylate). The compressor according to claim 6 , wherein the polymer brush has a crosslinked structure. The compressor according to any one of claims 1 to 9 , wherein a polymer is grafted onto the sliding surface and the sealing surface via an oxide containing silicon to form the polymer brush. A refrigeration cycle device including the compressor, a radiator, an expansion device, and a heat absorber according to any one of claims 1 to 10.

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