JP4872483B2 - Compressor - Google Patents

Description

  The present invention relates to a compressor used for refrigerating and air-conditioning for various uses regardless of business use and non-business use.

  A conventional orbiting scroll of a scroll compressor is disclosed in Patent Document 1, and its configuration is shown in FIGS. FIG. 5 is a partial cross-sectional view of the orbiting scroll, and FIG. 6 is a perspective view showing the appearance of the orbiting scroll.

  The orbiting scroll is composed of a disc-shaped end plate 21, a lap portion 22 formed upright in a spiral shape from an upper surface portion 21 c thereof, and a bearing portion 23. The height of the wrap portion is about three times the wall thickness. The base plate 21b and the base material 21b of the wrap part 22 are integrally formed, and the material is an aluminum die-cast product containing 30% silicon, some nickel, and magnesium. Further, the upper surface portion 21c and the side surface portion 21d of the end plate 21 and the wrap surface layer portion 22a of the wrap portion 22 are made of a powder sintered material made of the same material as the base material portion.

  Since the orbiting scroll configured in this way is lightweight, damage such as surface pressure on the bearing mechanism or the like is small even at a high speed of about 10,000 revolutions per minute. In addition, even if there are segregated parts in the base materials 21b and 22b, the surface layer parts 21a and 22a are uniformly powdered sintered materials such as silicon, so the cutting finish surface is also good, and the surface of the surface is subject to fatigue failure Thus, a highly reliable orbiting scroll member is formed in which no silicon drop-off portion occurs.

Therefore, if this orbiting scroll is mounted, the scroll compressor can be rotated at high speed, and a small size, light weight, high efficiency, and high reliability can be achieved.
JP-A-3-242486

  HFC refrigerants such as R410A, R407C, and R134a are used as refrigerants for refrigeration and air conditioning, but GWP is as high as 1300 to 1700, and there is a strong demand for changing to low GWP refrigerants to suppress global warming. Yes. An example of the candidate refrigerant is carbon dioxide.

  In the temperature range of the refrigeration and air conditioning, the pressure of carbon dioxide is very high, and the thrust portion of the orbiting scroll increases in surface pressure, making the sliding state more severe. In addition, carbon dioxide has a small polarity and is difficult to diffuse with synthetic oil, and uneven viscosity is likely to occur in the lubricating oil. For this reason, the oil film formation is not stable in the thrust part of the orbiting scroll, and the oil film may be partially cut to cause a decrease in lubricity. Therefore, even if the surface layer portion of the sliding portion is formed of an aluminum alloy powder sintered body, wear may increase, and suppression of wear is an issue of low GWP due to carbon dioxide.

  This invention solves such a conventional problem, and it aims at providing the compressor suitable for a low GWP refrigerant | coolant.

In order to solve the above problem, the present invention uses a refrigerant having a GWP of 150 or less and a polarity lower than that of R134a, and constitutes a sliding member with a material in which hard particles are dispersed in a soft substrate.
An inclined layer is provided on the surface layer of the sliding member to make the surface rich with a soft base material.

  As a result, the sliding surface of the sliding member is smoothed and the oil film forming ability on the sliding surface is improved, and the influence on the lubricity due to the low GWP and low polarity refrigerant is suppressed. Wear is prevented.

  The compressor of the present invention is suitable for low GWP, and can sufficiently suppress the influence of the refrigeration air conditioner on global warming.

  The invention according to claim 1 uses a refrigerant having a polarity lower than that of R134a and a GWP of 150 or less to form the sliding member with a material in which hard particles are dispersed in a soft base material. By providing an inclined layer on the surface layer portion to make the surface rich with a soft base material, the oil film forming ability on the sliding surface is improved, and a compressor suitable for a low GWP refrigerant is obtained.

  In the invention according to claim 2, the inclined layer of the surface layer portion of the sliding member is such that at least the sliding portion that receives the thrust load removes the soft base material of the surface layer portion to expose deep hard particles, The durability of the sliding member during transient operation is enhanced, and a compressor that is resistant to multiple refrigerants is obtained.

  In the invention according to claim 3, the hard particles have a rounded edge so that the exposed height is 1 μm or less, the compressive residual stress is applied to the soft base material around the hard particles, and the oxygen concentration is 3 to 3. By forming an oxide film of 30 wt%, the oil film forming ability of the sliding member at high load is increased, and a highly efficient compressor with low power consumption at high load is obtained.

  In the invention according to claim 4, by exposing the hard particles by an area ratio of 4.7% or more, the load bearing performance of the sliding member is increased, and a compressor having a wide operable load range can be obtained.

  In the invention according to claim 5, when the material of the sliding member is made of an Al-Si alloy, the sliding member is light and the number of revolutions that can be operated is increased, and a compressor having a wide capacity control range can be obtained. .

  In the invention according to claim 6, when Si is eutectic Si or refined primary crystal Si, the non-adhesiveness of the sliding member is increased, and a high compressor resistant to lubricating oil is obtained. .

  According to the seventh aspect of the present invention, since the sliding member is the orbiting scroll and the compressor is the scroll compressor, the torque fluctuation is small, and the vibration and noise are low. A compressor is obtained.

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

(Embodiment 1)
FIG. 1 is a cross-sectional view of a scroll compressor according to a first embodiment of the present invention.

  In FIG. 1, 1 is a sealed container, 2 is a suction pipe, and 3 is a discharge pipe. A compression mechanism unit 4 and a motor unit (not shown) are built in the sealed container 1. The compression mechanism unit 4 includes a fixed scroll 6 fixed to the frame 5, an orbiting scroll 7 disposed opposite to the fixed scroll 6, an Oldham ring 8 provided between the orbiting scroll 7 and the frame 5, and a motor unit. It is comprised from the crankshaft 9 connected.

  The fixed scroll 6 includes an end plate 6a, a spring 6b, a suction port 6c, and a discharge port 6d, and the suction pipe 2 is connected to the suction port 6c. FIG. 2 shows a sectional view of the orbiting scroll 7. The orbiting scroll 7 includes end plates 7a and 7b, springs 7c, and bearings 7d. The height of the springs 7c is set lower than the height of the springs 6b of the fixed scroll 6. The frame 5 is provided with a seal member 11 in the annular groove 10, and the inside of the seal member 11 is set to a high pressure. With this pressure, the orbiting scroll 7 is pressed against the fixed scroll 6 and the axial gap between the orbiting scroll 7 and the fixed scroll 6 is sealed.

  FIG. 3 shows a schematic diagram of a cross-sectional structure of the surface layer portion of the orbiting scroll 7. The orbiting scroll 7 is made of an Al—Si alloy 14 in which fine eutectic Si13, which is hard particles, is dispersed in Al12, which is a soft substrate, and an inclined layer 15 is formed on the surface layer portion. As the surface approaches, the amount of eutectic Si13 decreases, and the surface is rich in Al12. The surface of Al12 is smoothed by the effect of ductility, the roughness is as small as Rmax 1.0 or less, and it is very smooth.

  The refrigerant is carbon dioxide, GWP is 1.0, and the dipole moment with respect to polarity is 0 debye because the molecular structure is symmetric. On the other hand, the dipole moment of R134a is 2.06 debye. The lubricating oil is a synthetic oil.

  Next, the operation will be described.

  The rotation of the motor unit is transmitted to the orbiting scroll 7 via the crankshaft 9 and causes the orbiting scroll 7 to orbit in cooperation with the Oldham ring 8. The spring 7c of the orbiting scroll 7 and the spring 6b of the fixed scroll 6 which are disposed at positions engaged with each other by this orbiting motion suck in carbon dioxide from the suction pipe 2 through the suction port 6c and compress it. The compressed carbon dioxide is discharged into the sealed container 1 from the discharge port 6d, and is led out of the sealed container 1 from the discharge pipe 3. Accordingly, the inside of the sealed container 1 is at a high pressure.

  The inside of the seal member 11 is the discharge pressure, the orbiting scroll 7 is strongly pressed against the fixed scroll 6, and the end plate 7a of the orbiting scroll 7 is connected to the end of the end plate 6a of the fixed scroll 6 and the splash 6b of the fixed scroll 6. Slide. And although the lubricating oil intervenes in the sliding portion, the oil film is easily cut because there is uneven dissolution of carbon dioxide in the lubricating oil. However, since the end plate 7a of the orbiting scroll 7 is smooth, the oil film pressure of the lubricating oil interposed in the sliding portion increases, so that a sufficient oil film thickness can be ensured. Accordingly, wear of the sliding portion is suppressed, and a scroll compressor suitable for carbon dioxide can be obtained.

  In addition, since the surface of the orbiting scroll 7 is smooth, the gap around the splash 7c of the orbiting scroll 7, particularly the tip and other seal portions, can be reduced as much as possible, so that leakage from the seal portion is sufficiently suppressed. A highly efficient scroll compressor is obtained.

  Furthermore, since the scroll compressor has a small torque fluctuation, low vibration and low noise, it can be used as a refrigerating and air-conditioning apparatus for an apartment house where there is a strong demand for quietness.

(Embodiment 2)
FIG. 4 is a schematic view of the cross-sectional structure of the surface layer portion in the orbiting scroll of the scroll compressor according to the second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

The orbiting scroll 7 is made of an Al—Si alloy 14 in which fine eutectic Si13, which is hard particles, is dispersed in Al12, which is a soft substrate. The end plate 7a of the orbiting scroll 7 is subjected to grinding, mechanical polishing with a barrel, buff, fluid, or the like, or chemical polishing by etching, or a composite polishing thereof, and Al in the inclined layer is removed to obtain an average particle size of 3 Eutectic Si13 having a thickness of -10 μm is exposed. The exposure amount of the eutectic Si 13 is 4.7% or more in terms of area ratio, and the exposed height of the eutectic Si 13 is suppressed to 1 μm or less by rounding the edge of the exposed portion. If the exposure rate of the eutectic Si13 is less than 4.7% in terms of area ratio, the eutectic Si13 is too small to sufficiently impart non-adhesiveness. In addition, compressive residual stress is applied to the exposed Al12 around the eutectic Si13, and an oxide film 16 having an oxygen concentration of 3 to 30 wt% is also formed. If the oxygen concentration of the oxide film 16 is less than 5 wt%, the effect of the oxide film cannot be obtained, and if it exceeds 30 wt%, the roughness of the oxide film 16 increases. A more suitable oxygen concentration range is 5 to 20 wt%.

  Next, the operation will be described.

  In general, in transient operations such as start-up operation and defrosting operation in a refrigeration air conditioner, severe liquid return to the scroll compressor occurs. The lubricating oil is washed by the liquid refrigerant of carbon dioxide, and the lubrication state on the end plate 7a of the orbiting scroll 7 becomes more severe. In particular, the tendency becomes strong in a refrigerating and air-conditioning apparatus having a large capacity and a large number of refrigerants. However, since the fine eutectic Si 13 distributed on the end plate 7a of the orbiting scroll 7 exhibits high non-adhesiveness with respect to the fixed scroll which is the counterpart member, the orbiting scroll 7 has a high durability performance in transient operation. A scroll compressor resistant to refrigerant can be obtained.

  Further, since eutectic Si 13 is exposed by an area ratio of 4.7% or more and the bridging action is strengthened, the load-bearing performance of the orbiting scroll 7 is improved, and a scroll compressor having a wide operable load range is obtained.

  In addition, an oil reservoir is formed by Al12 around the eutectic Si13, and an oil film is formed by EHL on the exposed part of the eutectic Si. Therefore, the oil film forming ability of the orbiting scroll 7 under a high load increases, A highly efficient scroll compressor with low power consumption at the load can be obtained.

  In addition, the fine eutectic Si13 is firmly fixed to the surrounding Al12, and the surrounding Al12 has a high load-bearing performance due to non-adhesion, and is left unused for a long period of time, resulting in running out of lubricating oil. A scroll compressor can be obtained that can be started smoothly even when the engine is started, that is, during a temporary dry operation.

  Moreover, the scroll scroll 7 is light and can be rotated at high speed by the Al—Si alloy, and a scroll compressor having a wide capability control range can be obtained.

  The effects described above can be obtained in the same way even when an Al-Si alloy obtained by atomizing primary Si by atomization or an Al-Si alloy having a different Si content is used as a composite structure. It is what

  The refrigerant may be less polar than R134a and GWP is 150 or less, and may be nonflammable based on HFC, for example, a combination of a compound having a double bond, bromine, iodine, oxygen, or the like. Good. Further, the mixed refrigerant may include at least one having a polarity lower than that of R134a.

  As mentioned above, since the low GWP refrigerant | coolant can be used for the compressor concerning this invention by the oil film formation capability in a sliding surface, it can be applied also to the hot-water supply apparatus and washing machine using a refrigerating cycle.

Sectional drawing which shows the scroll compressor of 1st Example of this invention. Cross section of orbiting scroll Schematic diagram of the cross-sectional structure in the surface layer of the orbiting scroll The schematic diagram of the cross-sectional structure | tissue in the surface layer part of the scroll compressor of 2nd Example of this invention Partial sectional view showing a conventional orbiting scroll The perspective view which shows the external appearance of the conventional turning scroll

Explanation of symbols

7 Orbiting scroll 7a, 7b End plate 12 Al base 13 Eutectic Si
14 Al-Si alloy 15 Graded layer 16 Oxide coating

Claims (2)

A sliding member is made of a material having a GWP of 150 or less and a polarity lower than that of R134a, and a hard base material dispersed in a soft base material. A compressor rich in base material ,
The sliding part that receives at least a thrust load of the inclined layer has the hard particles exposed by removing the soft base material of the surface layer part,
The exposed height of the hard particles is 1 μm or less,
A compressor in which an oxide film having an oxygen concentration of 5 to 20 wt% is formed on the surface of the sliding member. It said sliding member is a orbiting scroll compressor according to claim 1 wherein the compressor is a scroll compressor.

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