JP2009138541A - Refrigerant compressor and bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing excellent in workability and wear resistance and a reliable refrigerant compressor. <P>SOLUTION: The refrigerant compressor 10 is provided with a compression means for compressing a refrigerant by rotation of a crankshaft 14 comprising a shaft part 31 and a crank part 32, the shaft part 31 is pivotally supported to a bearing 33, and the crank part 32 is engaged with a bearing 28. The bearings 28 and 33 are constituted by a carbon graphite composite material wherein half or more of opening pores of a carbon graphite base material having fixed carbon of 90 mass% or more and 99 mass% or less, a degree of graphite crystallinity of 50% or more and 85% or less and an area porosity of 15% or less are filled with α solid solution of copper (Cu) including tin (Sn). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigerant compressor used in a room air conditioner, a refrigerator, a water heater, and the like, and a bearing used in a rotation drive mechanism that is a structural element of the refrigerant compressor.

  In a refrigerant compressor used in a room air conditioner, a refrigerator, or the like, a rotary shaft for transmitting a driving force to a compression mechanism is supported by a bearing. Recently, with the growing interest in environmental problems such as prevention of ozone layer destruction, the use of natural refrigerants such as hydrofluorocarbons (HFC) and air instead of conventional fluorocarbon refrigerants containing a large amount of fluorine as refrigerants Is accelerating.

However, if an attempt is made to obtain the same cooling performance as when using a conventional fluorocarbon refrigerant using HFC or natural refrigerant, the internal pressure in the refrigerant compressor needs to be higher than before, so the load on the bearing is reduced. Increase. In such an environment, the lubrication film formed by the refrigerating machine oil is partially interrupted, and a so-called boundary lubrication state in which the bearing and the rotating shaft are in direct direct contact with each other easily occurs. In addition, a boundary lubrication state is likely to occur even when the refrigerant compressor is started or when excessive refrigerant is mixed. When the rotating shaft slides on the bearing in the boundary lubrication state, the wear of the bearing is accelerated. Therefore, a bearing made of a carbon graphite composite material in which bronze is infiltrated into pores of a carbon graphite base material having a small friction coefficient has been proposed as a bearing exhibiting high wear resistance (see, for example, Patent Document 1).
JP 2002-213356 A

  However, the bearing disclosed in Patent Document 1 has a low crystallinity of 15% to 40% in the fixed carbon of the carbon graphite composite material, and the remaining 60% to 85% is amorphous carbon having high hardness. Therefore, there is a problem that processing such as cutting and polishing is difficult. On the other hand, if the workability of the material used for the bearing is increased, the wear resistance may be reduced.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bearing having high wear resistance and excellent workability, and a highly reliable refrigerant compressor using the bearing.

  The refrigerant compressor according to the present invention includes compression means for compressing the refrigerant by driving the rotary shaft, and the rotary shaft is supported by a bearing. The bearing has a fixed carbon content of 90% to 99% by mass, a graphite crystallinity of 50% to 85% and an area porosity of 15% or less, and more than half of the open pores of the carbon graphite base material. A material made of a carbon graphite composite material filled with an α solid solution of copper (Cu) containing tin (Sn) is used.

  According to the present invention, it is possible to provide a bearing having both high wear resistance and excellent workability, and a highly reliable refrigerant compressor using the bearing.

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

<< First Embodiment >>
FIG. 1 is a sectional view showing a schematic structure of a refrigerant compressor according to the first embodiment of the present invention. The refrigerant compressor 10 is a so-called scroll type compressor, and is fixed to the fixed scroll 12 fixed inside the sealed container 11, the orbiting scroll 13 disposed so as to mesh with the fixed scroll 12, and the orbiting scroll 13. A crankshaft 14 for revolving with respect to the scroll 12 and a motor 15 for rotating the crankshaft 14 are provided.

  In the fixed scroll 12, a spiral (involute) wrap 22 is erected on a disc-shaped end plate 21, and a suction port 23 for sucking refrigerant is formed in the outer peripheral portion of the end plate 21, and is compressed in the center of the end plate 21. It has a structure in which a discharge port 24 for discharging refrigerant is formed, and is fixed to the frame 16 of the sealed container 11 so that the wrap 22 faces the motor 15 side. The orbiting scroll 13 has a structure in which a spiral wrap 26 is erected on a disc-shaped end plate 25. The orbiting scroll 13 is arranged with the wrap 26 facing the fixed scroll 12 so that the wrap 22 and the wrap 26 mesh with each other, and the shape on the surface perpendicular to the standing direction of the wraps 22 and 26 is thus a crescent shape. A compression chamber is formed.

  The crankshaft 14 includes a long shaft portion 31 and a short cylindrical crank portion 32 provided at the tip of the shaft portion 31 so as to be eccentric with respect to the shaft portion 31. The motor 15 is attached. The crankshaft 14 and the fixed scroll 12 are installed in the sealed container 11 so that the central axis of the shaft portion 31 and the central axis of the fixed scroll 12 coincide. As the crankshaft 14, carbon steel, low alloy steel, carburized and hardened steel, nitriding steel or cast iron is preferably used.

  A cylindrical convex portion 27 is formed at the center of the rear surface (the surface on which the wrap 26 is not erected) of the end plate 25 constituting the orbiting scroll 13, and a cylindrical bearing 28 is press-fitted into the convex portion 27. Thus, a bearing portion for engaging the crank portion 32 is formed. The frame 16 is formed with a cylindrical hole. A cylindrical bearing 33 is press-fitted into the inner periphery of the hole to form a bearing for supporting the shaft 31. . The crank portion 32 is inserted into a bearing portion provided in the orbiting scroll 13 and slides with respect to the bearing 28 by the rotation of the crankshaft 14. The shaft portion 31 is inserted into a bearing portion provided in the frame 16 and slides with respect to the bearing 33 by the rotation of the crankshaft 14.

  A constant narrow gap is formed between the outer peripheral surface of the crank portion 32 and the inner peripheral surface of the bearing 28, and a constant narrow gap is also formed between the outer peripheral surface of the shaft portion 31 and the inner peripheral surface of the bearing 33. The crankshaft 14 has a freedom of movement in the radial direction within a range allowed by these gaps.

  However, if the gap between the shaft portion 31 and the bearing 33 and the gap between the crank portion 32 and the bearing 28 are too wide, the cooling performance may be reduced due to the leakage of the refrigerant, or vibration noise may increase. Problems arise. On the other hand, if these gaps are too narrow, the rotation of the crankshaft 14 is hindered, and the friction loss increases. Further, if the surface conditions (for example, surface roughness) of the bearings 28 and 33 and the crankshaft 14 are not uniform, there is a possibility that local wear may occur or the rotational speed of the crankshaft 14 may fluctuate. . For this reason, the outer dimensions of the crankshaft 14 and the inner diameters of the bearings 28 and 33 are set to appropriate dimensions so as to avoid such problems, and the surface condition is also made uniform and smooth. The

  When the crankshaft 14 is rotated, the orbiting scroll 13 is eccentrically disposed with respect to the shaft portion 31 and the fixed scroll 12, so that the orbiting scroll 13 performs a revolving motion (orbiting motion) with respect to the fixed scroll 12. Do. In order to prevent rotation of the orbiting scroll 13 at that time, the Oldham ring is engaged with the key groove 35 provided on the back surface of the end plate 25 constituting the orbiting scroll 13 and the key groove 36 provided on the frame 16. 29 is arranged. Further, when the crankshaft 14 is rotated, a balance weight 37 is provided on the crankshaft 14 in order to prevent the crankshaft 14 from being shaken due to the crank portion 32 being provided at a position eccentric to the shaft portion 31. Is attached.

  When the crankshaft 14 is rotated, the fixed scroll 12 and the orbiting scroll 13 form the crescent-shaped compression chamber on the outer periphery thereof, and the refrigerant is taken into the compression chamber through the suction port 23. The refrigerant in the compression chamber is compressed as the compression chamber moves toward the center while gradually reducing the volume as the crankshaft 14 rotates. When the compression chamber communicates with the discharge port 24 formed in the center portion of the fixed scroll 12, the compressed refrigerant is discharged from the discharge port 24.

  Thus, in the refrigerant compressor 10, the compression chamber formed by the fixed scroll 12 and the orbiting scroll 13 and the motor 15 are coupled by the single crankshaft 14, and the bearings 28 and 33 support the load. Therefore, the bearings 28 and 33 are required to have high mechanical strength (particularly high compressive strength) in a lubricating oil environment in which refrigerant and refrigeration oil coexist.

  When the crankshaft 14 is rotated, a load acts on the crank portion 32 in a radial direction perpendicular to the eccentric direction by the fluid pressure of the refrigerant. The crankshaft 14 is tilted by this load, and the shaft portion 31 may be rotated against the bearing 33 while the crank portion 32 is strongly pressed against the bearing 28 in a single piece state. As a result, a load exceeding the oil film reaction force due to the refrigerating machine oil is applied to the bearings 28 and 33, and a boundary lubrication state in which the refrigerating machine oil does not exist in these sliding portions occurs.

  Further, when an inverter control method or a multi-refrigerant sealing method is used for rotational driving of the crankshaft 14, the viscosity of the refrigerating machine oil, the peripheral speed of the crankshaft 14 and the axial load fluctuate over a wide range, or an oil supply delay occurs during rapid start-up. When a phenomenon occurs, the lubrication mode of the sliding portion composed of the crankshaft 14 and the bearings 28 and 33 is changed from a steady fluid lubrication state to an intermediate mixed lubrication state, and further to the most severe boundary lubrication state. This shifts the bearing wear. This increase in the amount of wear causes noise and vibration, causes misalignment, deteriorates the sealing performance of the compression chamber, and reduces volumetric efficiency. Therefore, the bearings 28 and 33 are required to have excellent wear resistance even in a severe friction environment such as a boundary lubrication state. Furthermore, the bearings 28 and 33 are required to have a property (seizure resistance) that prevents the crankshaft 14 from seizing even when the lubricating oil environment changes.

  In order to satisfy such requirements and ensure high reliability over a long period of time, the bearings 28 and 33 have a fixed carbon content of 90% to 99% by mass, a crystallinity of 50% to 85%, and an area. A carbon graphite composite material in which more than half of the open pores of the carbon graphite base material having a porosity of 15% or less is filled with an α solid solution of copper containing tin (hereinafter referred to as “bronze”) is used.

  The carbon-graphite base material constituting the carbon-graphite composite was compression-molded by kneading carbonaceous powder, graphite powder, and a binder by a uniaxial press molding method or a cold isostatic pressing method (CIP). Then, it can manufacture by baking this at 1000 to 1500 degreeC for 1 to 2 months. The carbon graphite base material is composed of volatile matter, fixed carbon content, ash content, and moisture. Here, by adjusting the raw materials and the firing conditions, the carbon graphite material having a fixed carbon content of 90% by mass to 99% by mass. A substrate is produced. For example, in the case of a carbon graphite base material with a large amount of volatile matter and moisture, when the carbon graphite base material is heated to infiltrate bronze into the open pores of the carbon graphite base material later, There is a risk that defects such as cracks may occur in the carbon graphite base material due to volume expansion due to evaporation of moisture or the like. In addition, a carbon graphite base material having a large amount of fixed carbon is suitable as a bearing because it exhibits high compressive strength.

  That the degree of graphite crystallinity in the carbon graphite base material is less than 50% means that amorphous carbon (amorphous carbon), which is a carbon component other than crystalline graphite, is 50% or more. . When the content of amorphous carbon in the carbon graphite base material is large, the hardness of the amorphous carbon is high, so that processing such as cutting and polishing becomes difficult. On the other hand, when the degree of crystallinity of graphite exceeds 85%, the friction coefficient becomes small, but since the amount of amorphous carbon is small, the wear resistance in a severe friction environment such as a boundary lubrication state is low. Thus, by setting the degree of graphite crystallinity in the carbon graphite base material to 50% or more and 85% or less, it is possible to manufacture a bearing having a balance between workability and wear resistance.

  Graphite crystallinity in the carbon graphite substrate is identified by searching and collating the powder X-ray diffraction (XRD) chart of the carbon graphite substrate with JCPDS data (X-ray diffraction standard data collection). It was. Then, the integrated strength of the broad peak (carbon) and the sharp peak (graphite) is obtained by Graphite (002) peak profile fitting [Rigaku powder X-ray diffraction analysis software JADE7], and a standard sample (carbon: coke, The value was corrected with the sensitivity coefficient obtained from graphite: soil graphite), and the degree of graphite crystallization (integrated intensity ratio) was calculated.

  The area porosity of the carbon graphite base material refers to the area occupation ratio of pores in an observation image when the carbon graphite base material is cut and the cut surface is polished and the polished surface is observed with an SEM or an optical microscope. Point to. When the area porosity in the carbon graphite substrate is more than 15%, the mechanical strength of the carbon graphite substrate is lowered. Further, the amount of bronze to be infiltrated increases, and seizure to the crankshaft 14 is likely to occur. Therefore, the area porosity in the carbon graphite base material is set to 15% or less.

  Bronze is infiltrated (impregnated) into the carbon graphite substrate so that more than half of the open pores of the carbon graphite substrate are filled with bronze. Infiltration of bronze into the carbon graphite base material can be performed, for example, by the following method. First, a heatable metal melting crucible is provided inside a pressure-resistant vessel that can be adjusted to either a vacuum atmosphere or a pressurized gas atmosphere, and bronze (or a tin-copper powder or lump of constant composition, etc.) is provided in this crucible. ) Is charged in a predetermined amount and melted. Subsequently, the carbon graphite base material is housed in a pressure resistant container without being immersed in the molten bronze in the crucible, and the pressure inside the pressure resistant container is reduced to remove air in the open pores of the carbon graphite base material. Next, after immersing the carbon graphite base material in the molten bronze in the crucible, the molten bronze is permeated into the open pores of the carbon graphite base material by supplying nitrogen gas or the like into the pressure vessel and internally pressurizing it. . After performing the infiltration treatment for a predetermined time in this manner, the crucible temperature is lowered to solidify the molten bronze (or the carbon bronze base material is pulled up to solidify the molten bronze that has penetrated into the carbon graphite base material), and obtained. A carbon graphite composite material is cut out from the solidified material. A bearing can be manufactured by cutting or polishing the obtained carbon graphite composite material into a desired size and shape of the bearing.

  Bronze is used because pure copper is prone to weight deformation and the seizure resistance to the crankshaft is not sufficient. Adding tin to copper makes it hard while maintaining the excellent wear resistance of copper. This is because seizure resistance is also improved. In addition, since melting | fusing point falls when a predetermined amount of tin is added to copper, there exists an advantage that the apparatus load in an infiltration process can be reduced. In addition, the melting point of bronze is lower than that of pure copper, but it is still sufficiently higher than the temperature that is expected to occur in the bearing. Even if the temperature rises, the wear resistance can be maintained.

  Filling more than half of the open pores of the carbon graphite base material with bronze can effectively prevent the occurrence of oil film breakage due to penetration of refrigerating machine oil into the open pores of the carbon graphite base material. In order to increase the filling ratio of bronze to the carbon graphite base material with a constant area porosity, a large pressure is required when infiltrating the molten bronze into the carbon graphite base material. Will increase. Therefore, it is preferable to determine the infiltration conditions in consideration of the balance between the filling amount that provides effective characteristics as a bearing and the equipment load for realizing the filling amount.

  As shown in the examples to be described later, the compression strength is increased by infiltrating bronze into the open pores of the carbon graphite base material, so that it is able to withstand a large load and the wear resistance is also improved. . In order to obtain such an effect, the area porosity of the carbon graphite base material is preferably 5% or more so that a certain amount of bronze can be infiltrated.

FIG. 2 shows the composition dependence of the relationship between temperature and product phase and mechanical properties (tensile strength: σ _B , hardness: H _B , elongation: δ) in the copper-tin system. FIG. 2 shows that in order to fill the carbon graphite base material with the bronze α-solid solution, the tin content needs to be about 12 mass% or less. From the viewpoint of reliably producing an α solid solution after the infiltration treatment, it is preferable that the upper limit value of the amount of tin added is 11% by mass.

It can also be seen that in the region where the tin content is 12% by mass or less, as the tin content increases, the tensile strength σ _B increases and becomes harder and the elongation decreases. For example, by setting the tin content to 10% by mass, the tensile strength σ _B is about 1.8 times and the hardness H _B is about 1.6 times. By filling the pores with bronze, the mechanical properties of the carbon graphite composite can be improved. However, when the tin content is less than 5% by mass, the improvement effect of the mechanical properties due to bronzing cannot be said to be sufficient, and it is sufficient when the lubricating oil environment changes to become a severe friction environment. May not be able to obtain good wear resistance. Therefore, the tin content is preferably 5% by mass or more.

  The compressive strength of the carbon graphite composite material produced as described above is preferably 300 MPa or more, as shown in the examples described later. Thereby, even in a severe friction environment such as a boundary lubrication state, Excellent wear resistance. Such a carbon graphite composite material can be produced by appropriately setting the production conditions of the carbon graphite base material and the infiltration conditions of bronze.

  The bearings 28 and 33 exhibit excellent wear resistance and seizure resistance even when the internal pressure of the refrigerant compressor 10 is large. For this reason, in the refrigerant compressor 10, it is preferable to actively use a halogenated hydrocarbon refrigerant (HFC), hydrocarbon refrigerant (HC), or natural refrigerant in consideration of environmental problems such as ozone depletion. it can. Corresponding to such refrigerants, mineral oil, polyol ester oil, polyalkylene glycol oil, polyvinyl ether oil, polyalphaolefin oil, and hard alkylbenzene oil are preferably used as the refrigerating machine oil.

  The moisture in the refrigeration oil hydrolyzes and degrades the refrigeration oil, thereby deteriorating the frictional environment between the crankshaft 14 and the bearings 28 and 33. In particular, the refrigerating machine oil used when R744, R410A, R407C, R134a, R600a, and R290 are used as the refrigerant is easy to take in moisture and is easily hydrolyzed by the taken-in moisture. Therefore, the moisture in the refrigerating machine oil is preferably 1 to 1000 ppm, and more preferably 1 to 500 ppm. In addition, although it is very preferable that the water | moisture content in refrigerating machine oil is less than 1 ppm, a lot of labor is required to make the water | moisture content in refrigerating machine oil less than 1 ppm actually.

<< Second Embodiment >>
FIG. 3 is a cross-sectional view showing a schematic structure of a refrigerant compressor according to the second embodiment of the present invention. The refrigerant compressor 50 is a so-called rotary compressor, and includes a motor 52 disposed in an airtight container 51, a crankshaft 53 attached to the motor 52, and a first shaft for supporting the crankshaft 53. Bearing 54 and second bearing 55, cylinder 56 interposed between first bearing 54 and second bearing 55, roller 57 provided in cylinder 56, and radial direction of cylinder 56 with respect to cylinder 56 A vane 58 is slidably attached to the roller 57 so as to be slidable.

  The crankshaft 53 has a structure in which a crank portion 63 is provided between the first shaft portion 61 and the second shaft portion 62, and the first shaft portion 61 is attached to the motor 52. The first bearing 54 is provided with a hole for pivotally supporting the first shaft portion 61, and a bearing 71 is press-fitted and fixed to the hole, and the first shaft portion 61 slides relative to the bearing 71. To do. Similarly, the second bearing 55 is provided with a hole for supporting the second shaft portion 62, and a bearing 72 is press-fitted and fixed to the hole, and the second shaft portion 62 is fixed to the bearing 72. Slide.

  A bearing 73 is press-fitted inside the roller 57, and the crank portion 63 slides with respect to the bearing 73 by the rotation of the crankshaft 53, giving the roller 57 an eccentric rotation, and the roller 57 does not rotate. A swiveling motion is performed with respect to the cylinder 56. The sealed container 51 is provided with a suction port 65, and the refrigerant gas sucked into the cylinder 56 from the suction port 65 is compressed by the turning motion of the roller 57, and then the discharge port provided in the sealed container 51. 66 is discharged.

  Also in the refrigerant compressor 50, as the bearings 71 to 73, a carbon graphite material having a fixed carbon content of 90% to 99% by mass, a graphite crystallinity of 50% to 85%, and an area porosity of 15% or less. Even if a severe frictional environment such as a boundary lubrication state occurs by using a carbon graphite composite material in which more than half of the open pores of the base material are filled with an α solid solution of bronze, wear of the bearings 71 to 73 occurs. Further, seizure with the crankshaft 53 can be suppressed. Thus, the reliability and durability of the refrigerant compressor 50 can be improved.

  As described above, the scroll type compressor and the rotary type compressor have been described as the embodiment of the refrigerant compressor according to the present invention. However, the present invention is not limited thereto, and the compression mechanism may be a reciprocating type, a swing type, or a screw type. Often, the above-described carbon graphite composite material can be used as a bearing in these various compression mechanisms. Moreover, the above-described carbon graphite composite material is not limited to the bearing, but is also suitably used as a component constituting another sliding portion in the refrigerant compressor. For example, by using as sliding parts such as rollers, vanes, and pistons, durability can be improved due to excellent wear resistance.

  Next, as an example, the result of evaluating the wear resistance of the carbon graphite composite material used for the bearing will be described. Table 1 shows the fixed carbon content, graphite crystallization rate, and area porosity of the samples prepared. As described above, these samples were produced by compressing and molding a kneaded carbonaceous powder, graphite powder, and binder and firing in a firing furnace at 1000 ° C. for one month. The fixed carbon content was evaluated by an ashing method, the graphite crystallization rate was evaluated by diffraction peak separation on the (002) plane of graphite in the XRD chart, and the area porosity was determined by SEM observation.

The infiltrated materials shown in Table 1 were infiltrated into the produced carbon graphite base material. For infiltration, a bar material (22-25 mm × 22-25 mm × 275-285 mm) is set in an impregnation furnace, the inside of the furnace is deaerated (0.5 MPa), and the infiltration material is heated to a temperature 100 ° C. higher than the melting point. After immersion in the molten metal, it was performed by pressurizing at a pressure of 100 kg / cm ² for 1 to 1.5 hours. When the cross section of the infiltrated sample was observed by SEM, it was confirmed that about 90% of the open pores were filled with the infiltrating material.

  The compressive strength of the produced carbon graphite composite material was determined by applying a load at 5 mm / s with an universal testing machine manufactured by Instron and dividing the breaking load by the contact area. The results are also shown in Table 1. As is clear from comparison between Examples 1 and 2 and Comparative Examples 1 and 2, it can be seen that the compressive strength is improved by infiltration of bronze. In Comparative Examples 3 and 4, since the degree of crystallinity of the carbon graphite base material is large, the compressive strength remains at a low value.

  The abrasion test was performed using a high-pressure atmosphere abrasion tester [Orientec Co., Ltd. (currently A & D Co., Ltd .: AFT-18-800S)]. More specifically, the carbon graphite composite material is processed into a shape of 10 mm × 10 mm × 36 mm to form a fixed test piece, and a carburized and quenched material of SCM415 is pressed against the movable piece as a movable piece at a surface pressure of 9.8 MPa to slide. The speed was set to 1.2 m / sec, and sliding was performed for 2 hours in an R410A refrigerant atmosphere (excluding refrigerating machine oil). The results of measuring the wear amount of the fixed test piece after the test are shown in FIG.

  In this wear test, since the refrigerating machine oil is not used, the frictional environment between the fixed test piece and the movable piece is set to extremely severe conditions. As shown in FIG. 4, in Examples 1 and 2, the amount of wear was as small as about 5 μm, and it was confirmed that good wear resistance was exhibited. On the other hand, in Comparative Examples 3 and 4 where the compressive strength is as low as about 150 MPa, the amount of wear was extremely large compared to other samples, indicating about five times the amount of wear as in Examples 1 and 2. . In Comparative Examples 1 and 2 in which bronze is not infiltrated, the compressive strength is about 270 MPa, and thus relatively good wear resistance is obtained. However, the wear is about twice that of Examples 1 and 2. Indicates the amount. From these results, it was determined that the compressive strength of the carbon graphite composite used for the bearing is preferably 300 MPa or more.

  Next, in order to examine the composition of bronze infiltrated into the carbon graphite base material, as a carbon graphite composite material according to Example 3, the carbon graphite base material shown in Table 1 has a tin content of 20% by mass. What infiltrated bronze with the remainder being copper was newly produced. The compressive strength of the carbon graphite composite material according to Example 3 was measured using the universal testing machine described above. The results are also shown in Table 1. Moreover, the abrasion test of the carbon graphite composite material according to Example 3 using the above-described high-pressure atmosphere abrasion tester was performed in the same manner as the abrasion tests of Examples 1 and 2 and Comparative Examples 1 to 4. The relationship between the amount of wear and the compressive strength in Example 3 is also shown in FIG. Further, the wear amount of Example 3 is shown in FIG. 5 in comparison with the wear amounts of Example 2 and Comparative Example 1.

  In Example 3, although the amount of wear was slightly larger than that in Example 2, it was found that the amount of wear was sufficiently small as compared with Comparative Example 1. From this result, when bronze is infiltrated into the carbon graphite base material, it is judged that the tin content is 10% by mass from the viewpoint of improving wear resistance.

Sectional drawing which shows schematic structure of the refrigerant compressor which concerns on 1st Embodiment of this invention. The figure which shows the relationship between the temperature in a copper-tin type | system | group and a production | generation phase, and the composition dependence of a mechanical characteristic. Sectional drawing which shows schematic structure of the refrigerant compressor which concerns on 2nd Embodiment of this invention. The figure which shows the relationship between the compressive strength of Examples 1-3 and Comparative Examples 1-4, and the amount of wear. The graph which shows the abrasion loss of Example 2, 3 and the comparative example 1. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Refrigerant compressor, 11 ... Sealed container, 12 ... Fixed scroll, 13 ... Orbiting scroll, 14 ... Crankshaft, 15 ... Motor, 16 ... Frame, 21 ... End plate, 22 ... Wrap, 23 ... Inlet, 24 ... Exhaust Outlet, 25 ... End plate, 26 ... Lap, 27 ... Projection, 28 ... Bearing, 29 ... Oldham ring, 31 ... Shaft, 32 ... Crank, 33 ... Bearing, 35 ... Keyway, 36 ... Keyway, 37 ... Balance weight, 50 ... refrigerant compressor, 51 ... sealed container, 52 ... motor, 53 ... crankshaft, 54 ... first bearing, 55 ... second bearing, 56 ... cylinder, 57 ... roller, 58 ... vane, 61 ... first DESCRIPTION OF SYMBOLS 1 shaft part, 62 ... 2nd shaft part, 63 ... Crank part, 65 ... Inlet port, 66 ... Discharge port, 71 ... Bearing, 72 ... Bearing, 73 ... Bearing

Claims (11)

A refrigerant compressor provided with a compression means for compressing refrigerant by rotation of a rotating shaft,
The compression means includes a bearing that supports the rotating shaft,
The bearing has a fixed carbon content of 90% by mass or more and 99% by mass or less, a graphite crystallinity of 50% or more and 85% or less, and an area porosity of 15% or less and more than half of the open pores of the carbon graphite base material. A refrigerant compressor comprising a carbon graphite composite material filled with an α solid solution of copper containing tin. A refrigerant compressor provided with a compression means for compressing a refrigerant by driving a rotary shaft and a crank attached to the rotary shaft,
The compression means includes a first bearing that pivotally supports the rotating shaft, and a second bearing that engages with the crank,
At least the second bearing of the first bearing and the second bearing has a fixed carbon content of 90% by mass to 99% by mass, a graphite crystallinity of 50% to 85%, and an area porosity. A refrigerant compressor comprising a carbon graphite composite material in which more than half of the open pores of a carbon graphite base material, which is 15% or less, are filled with an α solid solution of copper containing tin.   The refrigerant compressor according to claim 1 or 2, wherein the carbon graphite composite material has a compressive strength of 300 MPa or more.   4. The refrigerant compressor according to claim 1, wherein a content ratio of tin in the α solid solution is 5% by mass or more and 11% by mass or less. 5.   The said refrigerant | coolant consists of 1 type, or multiple types chosen from the halogenated hydrocarbon type refrigerant | coolant, the hydrocarbon type refrigerant | coolant, and the natural type refrigerant | coolant, The any one of Claims 1-4 characterized by the above-mentioned. Refrigerant compressor.   The refrigerating machine oil used for the compression means comprises one or more selected from mineral oil, polyol ester oil, polyalkylene glycol oil, polyvinyl ether oil, polyalphaolefin oil and hard alkylbenzene oil. The refrigerant compressor according to any one of claims 1 to 5.   The refrigerant compressor according to claim 6, wherein a moisture concentration in the refrigerant and the refrigerating machine oil is 1 ppm or more and 1000 ppm or less.   The refrigerant compression according to any one of claims 1 to 7, wherein the compression means has a structure of any one of a reciprocating type, a rotary type, a scroll type, a swing type, and a screw type. Machine.   The compression means has a fixed carbon content of 90% by mass or more and 99% by mass or less, a graphite crystallinity of 50% or more and 85% or less, and an area porosity of 15% or less and more than half of open pores of the carbon graphite base material. 9. The apparatus according to claim 1, further comprising at least one of a roller, a vane, and a piston made of a carbon graphite composite material filled with an α solid solution of copper containing tin. The refrigerant compressor described in 1.   Copper having a fixed carbon content of 90% by mass or more and 99% by mass or less, a graphite crystallinity of 50% or more and 85% or less and an area porosity of 15% or less, and more than half of the open pores of the carbon graphite base material containing tin A bearing comprising a carbon-graphite composite material filled with an α solid solution.   The bearing according to claim 10, wherein the compressive strength is 300 MPa or more.

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