JP2010084583A - Sliding member and compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable sliding member for a compressor with increased adhesiveness of phosphate coating and with high oil retaining capability, and to provide an highly reliable and highly efficient compressor. <P>SOLUTION: Iron phosphate 128 is formed to the depth of 0.5 μm from a surface of material of a sliding part, wherein weight percent of phosphorus is within a range of 5-15%, weight percent of manganese is within a range of 5-20%, and weight percent of iron is within a range of 70-85%. The adhesiveness between the material of the sliding member and the phosphate coating 127 is improved by forming the phosphate coating 127 with coating thickness of 0.5 to 2.5 μm and particle diameter of 5 μm or less, the oil retaining capability is improved, and abrasion resistance is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sliding member in which a phosphate film having excellent wear resistance and initial conformability is formed on a sliding surface of a steel product such as a piston or a crankshaft, and a compression used for a refrigerator or an air condenser. Related to the machine.

  In recent years, high-efficiency compressors have been developed to reduce the use of fossil fuels from the viewpoint of protecting the global environment.

  Conventionally, a phosphate coating is formed on the sliding surfaces of compressor pistons, crankshafts, etc. to eliminate irregularities on the machined surface and improve the initial familiarity between the sliding parts. There is a description about a member and a compressor (for example, refer to patent documents 1).

  The conventional sliding member and compressor will be described below with reference to the drawings.

  FIG. 8 is a longitudinal sectional view of a conventional compressor described in Patent Document 1, and FIG. 9 is a cross-sectional view of a main part of a conventional sliding member described in Patent Document 1.

  As shown in FIG. 8, the sealed container 1 stores oil 2 at the bottom, and houses an electric element 5 including a stator 3 and a rotor 4, and a reciprocating compression element 6 driven by the electric element 5. ing.

  Next, details of the compression element 6 will be described below.

  The crankshaft 7 includes a main shaft portion 8 into which the rotor 4 is press-fitted and fixed, an eccentric shaft 9 formed eccentric to the main shaft portion 8, and an oil supply pump 10.

  Further, the cylinder block 11 forms a compression chamber 13 composed of a substantially cylindrical bore 12 and is provided with a bearing portion 14 that supports the main shaft portion 8.

  The piston 15 loosely fitted to the bore 12 is connected to the eccentric shaft 9 via a piston pin 16 by a connecting rod 17 as a connecting means.

  The end face of the bore 12 is sealed with a valve plate 18.

  The head 19 forms a high pressure chamber (not shown) and a low pressure chamber (not shown), and is fixed to the valve plate 18 on the side opposite to the bore 12.

  The suction tube 20 is fixed to the sealed container 1 and connected to the low-pressure side (not shown) of the refrigeration cycle, and guides the refrigerant gas into the sealed container 1. The suction muffler 21 is sandwiched between the valve plate 18 and the head 19.

  The main shaft portion 8 and the bearing portion 14 of the crankshaft 7, the piston 15 and the bore 12, the piston pin 16 and the connecting rod 17, and the eccentric shaft 9 and the connecting rod 17 of the crankshaft 7 form a sliding portion. Is formed with an insoluble phosphate film 22 made of a porous crystal on the surface of one of the sliding portions.

  In FIG. 9, a sliding part formed by the piston 15 and the bore 12 is shown as an example of the sliding part, and an insoluble phosphate film 22 made of a porous crystal is formed on the sliding part surface of the piston. Is forming.

  The operation of the compressor configured as described above will be described below.

  Electric power supplied from a commercial power source (not shown) is supplied to the electric element 5 to rotate the rotor 4 of the electric element 5. The rotor 4 rotates the crankshaft 7, and the eccentric movement of the eccentric shaft 9 is transmitted from the connecting rod 17, which is a connecting means, to the piston 15 via the piston pin 16. The piston 15 reciprocates in the bore 12, and the suction tube The refrigerant gas introduced into the sealed container 1 through 20 is sucked from the suction muffler 21 and continuously compressed in the compression chamber 13.

  As the crankshaft 7 rotates, the oil 2 is supplied to the sliding portions from the oil pump 10 to lubricate the sliding portions, and at the sliding portions of the piston 15 and the bore 12, phosphorus, which is a porous crystal body, is provided. The oil 2 is held by the acid salt film 22 and serves as a seal.

  Here, the piston 15 and the bore 12 are loosely fitted with a very narrow clearance in order to reduce leakage loss. As a result, depending on the variations in the shape and accuracy of the piston 15 and the bore 12, there may be a portion that causes partial mutual contact.

However, by forming the phosphate coating 22 on the sliding surface of the piston 15, the phosphoric acid formed on the surface of the piston 15 even when the speed of the piston 15 becomes zero at the top dead center and the bottom dead center. The salt coating 22 can prevent metal contact with the bore 12.
Japanese Patent Application Laid-Open No. 7-238885

  However, when the conventional sliding member is used in an environment where the viscosity of the oil is high, the retainability of the oil can be obtained by taking advantage of the shape of the porous crystalline body of the phosphate film. Due to the lower viscosity of the oil due to the higher efficiency of the compressor, the ability to retain the oil due to the porous crystal shape of the phosphate film decreases, resulting in a decrease in the sealing performance between the piston and the bore due to the oil. However, there is a problem that the wear resistance is lowered due to an increase in the load on the phosphate film.

  The present invention solves the above-described conventional problems, and provides a sliding member that improves the adhesion between the material and the phosphate coating and improves the oil retention by controlling the shape of the phosphate coating. The object is to provide a highly reliable and highly efficient compressor.

  In order to solve the above-mentioned conventional problems, the sliding member of the present invention has a phosphate film and a sliding part material by limiting the composition ratio of iron phosphate from the surface to the inside of the sliding part material. By improving the adhesion with the oil and limiting the film thickness and particle diameter of the phosphate film, it has the effect of increasing the oil retention.

  The sliding member and the compressor of the present invention form a phosphate film on the surface of the sliding part material, and the weight composition ratio of phosphorus is 5 to 5 μm from the surface of the sliding part material to 0.5 μm. In the range of 15%, the weight composition ratio of manganese is in the range of 5 to 20%, the weight composition ratio of iron is in the range of 70 to 85%, and the film thickness is 0.5 to 2.5 μm on the sliding surface. With a particle diameter of 5 μm or less, improved adhesion between the phosphate coating and the sliding member, and increased oil retention by the phosphate coating, with high performance and high reliability. And a highly reliable and highly efficient compressor.

  According to the first aspect of the present invention, a phosphate film is formed on the surface of the sliding part material, and the weight composition ratio of phosphorus is 5 to 5 at least at a depth of 0.5 μm from the surface of the sliding part material. It is composed of iron phosphate salt in which the weight composition ratio of manganese is in the range of 5-20% and the weight composition ratio of iron is in the range of 70-85% within the range of 15%. Since the adhesiveness between the sliding part material and the phosphate film is increased by increasing the reactivity between the part material and the phosphate film, a highly reliable sliding member can be formed.

  The invention according to claim 2 is the invention according to claim 1, wherein the thickness of the phosphate film is in the range of 0.5 to 2.5 μm, and the particle diameter of the phosphate film is 5 μm. In order to prevent metal contact with a phosphate film, which is an insoluble film and a porous crystal, and to increase the oil retention and prevent the sliding part from being worn, In addition to the effects of the described invention, a highly reliable sliding member can be formed.

  According to a third aspect of the present invention, oil is stored in a sealed container and a compression element is accommodated, and the compression element is formed integrally with the crankshaft having a main shaft and an eccentric shaft, and one of the compression shaft and the crankshaft. A thrust portion integrally formed on the bearing portion, the bearing portion rotatably supporting the main shaft, a cylinder block forming a compression chamber, a piston reciprocating in the compression chamber, and the eccentricity A reciprocating type compression element comprising a piston pin arranged in parallel to a shaft and fixed to the piston, and a connecting rod for linking the eccentric shaft and the piston, the crankshaft, the thrust portion, the cylinder block, The sliding member according to claim 1 or 2 is used for at least one of the piston, the piston pin, and the connecting rod. By reducing the particle size of the phosphoric acid by increasing the film thickness of the phosphate film on the surface of the sliding part and making the particles finer. Since the wettability between the salt film and oil can be improved and the oil retention can be improved, a highly reliable compressor with excellent sealing and wear resistance in sliding parts such as between the piston and bore Can be provided.

  The invention according to claim 4 uses the oil of viscosity grade VG10 or less in the invention according to claim 3, and even in a low viscosity oil, the retention of oil by the phosphate coating on the surface of the sliding portion is achieved. Since the amount of leakage between the sliding portions can be reduced, it is possible to provide a compressor having excellent wear resistance and high refrigeration capacity in addition to the effect of the invention of claim 3.

  According to a fifth aspect of the present invention, in the fourth aspect of the invention, the electric element for driving the compression mechanism is provided, and the electric element is inverter-driven at a plurality of operation frequencies including at least an operation frequency equal to or lower than a power supply frequency. In addition to the effects of the invention according to claim 4, since the oil retaining force by the phosphate film on the surface of the sliding portion is high, the fluid lubrication state can be maintained even when the driving speed is slow. Furthermore, it is possible to provide a compressor having excellent wear resistance and high refrigerating capacity.

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

(Embodiment 1)
1 is a longitudinal sectional view of a compressor according to Embodiment 1 of the present invention, FIG. 2 is an enlarged view of part A in FIG. 1, FIG. 3 is an enlarged view of part B in FIG. 2, and FIG. It is a relationship diagram of thickness and the amount of wear, and shows the relationship between the film thickness of the phosphate film and the amount of sliding wear.

  FIG. 5 is a diagram showing the relationship between the particle diameter and the amount of wear in the same embodiment, and shows the relationship between the particle size of the phosphate coating and the amount of sliding wear. FIG. 6 is a relationship diagram between the iron phosphate salt depth and the wear amount in the same embodiment, and shows the adhesion of the phosphate coating. FIG. 7 is a characteristic diagram of the reciprocating compressor according to the embodiment.

  In FIG. 1 to FIG. 3, the airtight element 101 is filled with the refrigerant gas 102 made of R134a, and the oil 103 made of the ester system of VG10 is stored at the bottom, and the electric element made of the stator 104 and the rotor 105 is stored. 106 and a reciprocating compression element 107 driven thereby are accommodated.

  Next, details of the compression element 107 will be described below.

  The crankshaft 108 includes a main shaft 109 in which the rotor 105 is press-fitted and fixed, and an eccentric shaft 110 formed eccentric to the main shaft 109, and an oil supply pump 111 communicating with the oil 103 is provided at the lower end. The cylinder block 112 made of cast iron forms a substantially cylindrical bore 113 and a bearing portion 114 that supports the main shaft 109.

  Further, the rotor 105 is formed with a flange surface 115, and the upper end surface of the bearing portion 114 is a thrust portion 116. A thrust washer 117 is inserted between the flange surface 115 and the thrust portion 116 of the bearing portion 114. A thrust bearing portion 118 is configured by the flange surface 115, the thrust portion 116, and the thrust washer 117.

  In order to reduce leakage loss, the piston 119 loosely fitted into the bore 113 while maintaining a certain amount of clearance is made of cast iron or an iron-based material, forms a compression chamber 120 together with the bore 113, and the piston pin 121 is The connecting shaft 122 is connected to the eccentric shaft 110 through a connecting means. The piston 119 and the bore 113 are loosely fitted with a clearance of about 5 to 15 μm, for example, due to a difference in diameter.

  The end surface of the bore 113 is sealed with a valve plate 123. The head 124 forms a high pressure chamber (not shown) and a low pressure chamber (not shown), and is fixed to the valve plate 123 on the side opposite to the bore 113. The suction tube 125 is fixed to the sealed container 101 and connected to the low-pressure side (not shown) of the refrigeration cycle, and guides the refrigerant gas 102 into the sealed container 101. The suction muffler 126 is sandwiched between the valve plate 123 and the head 124.

  The piston 119 and the bore 113, the main shaft 109 and the bearing portion 114, the thrust portion 116 and the thrust washer 117, the piston pin 121 and the connecting rod 122, the eccentric shaft 110 and the connecting rod 122 form a sliding portion, and each sliding member A phosphate film 127 is formed on at least one of the above.

  Here, the piston 119 will be described in detail as an example.

  Among the sliding portions formed by the piston 119 and the bore 113, a phosphate film 127, which is a porous crystal body, is formed of an insoluble film on the sliding surface of the piston 119.

  In the embodiment of the present invention, the phosphate film 127 has a film thickness of 0.5 μm or more and a particle diameter of 5 μm or less. Further, in order to improve the adhesion between the phosphate coating 127 and the piston material in the sliding part, the weight composition ratio of phosphorus is in the range of 5 to 15% at a depth of 0.5 μm from the surface of the sliding part material. In which the weight composition ratio of manganese is in the range of 5 to 20% and the weight composition ratio of iron is in the range of 70 to 85%. An acid salt film 127 is formed.

  The operation of the reciprocating compressor in which the above-described piston 119 is mixed will be described below.

  Electric power supplied from a commercial power source (not shown) is supplied to the electric element 106 to rotate the rotor 105 of the electric element 106. The rotor 105 rotates the crankshaft 108, and the eccentric movement of the eccentric shaft 110 drives the piston 119 from the connecting rod 122, which is a connecting means, via the piston pin 121, so that the piston 119 reciprocates in the bore 113, The refrigerant gas 102 introduced into the sealed container 101 through the suction tube 125 is sucked from the suction muffler 126 and compressed in the compression chamber 120.

  As the crankshaft 108 rotates, the oil 103 is supplied to each sliding portion from the oil supply pump 111 to lubricate the sliding portion, and also serves as a seal between the piston 119 and the bore 113.

  The refrigerant gas 102 compressed in the compression chamber 120 passes through a discharge tube (not shown), is discharged into a refrigeration cycle (not shown), circulates in the refrigeration cycle (not shown), and sucks again. It is guided into the sealed container 101 from the tube 125.

  When the piston 119 reciprocates in the bore 113, the clearance between the piston 119 and the bore 113 is very narrow. Sometimes it happens.

  Even in such a case, metal phosphate is prevented by the phosphate film 127 which is an insoluble film whose adhesion to the piston material is enhanced by the iron phosphate salt 128, and the phosphate which is a porous crystal is also used. Since the oil retaining force of the oil 103 can be increased by the particle shape of the coating 127, the sliding portion between the piston 119 and the bore 113 is always in a fluid lubrication state and is not easily worn, and the compressed refrigerant gas 102 flows between the piston 119 and the bore 113. Since leakage from the clearance can be reduced, a highly efficient and highly reliable compressor can be provided.

  Details of the efficiency of the compressor will be described later.

  Next, regarding the sliding characteristics of the phosphate film, an iron-based test piece that has been subjected to a phosphate film treatment in the presence of refrigerant gas composed of R134a and oil composed of ester of VG10 is 1.0 m / s. Evaluation was performed by an environmental wear test by rotating the cast iron ring at a speed of 100 N. The relationship between the phosphate film shape and the sliding wear amount will be described with reference to FIGS. 4 and 5, and the relationship between the iron phosphate salt depth and the sliding wear amount will be described with reference to FIG.

  In FIG. 4, the horizontal axis indicates the thickness of the phosphate film, and the vertical axis indicates the amount of sliding wear. The particle diameter of the phosphate coating in this test was 3.0 μm, and at a depth of 0.5 μm from the surface of the sliding part material, the weight composition ratio of phosphorus was 7%, the weight composition ratio of manganese was 8%, iron Was composed of a phosphate having a weight composition ratio of 85%.

  FIG. 4 shows that the amount of wear during sliding is reduced when the film thickness is 0.5 μm or more.

  In FIG. 5, the horizontal axis represents the particle diameter of the phosphate coating, and the vertical axis represents the sliding wear amount. In this test, the thickness of the phosphate film is 1.0 μm, and at a depth of 0.5 μm from the surface of the sliding part material, the weight composition ratio of phosphorus is 7%, the weight composition ratio of manganese is 8%, iron Was composed of a phosphate having a weight composition ratio of 85%.

  FIG. 5 shows that the amount of wear during sliding is reduced when the particle size is 5 μm or less.

  Therefore, by increasing the thickness of the phosphate coating and making the particles finer, the surface area of the phosphate coating increases, resulting in improved wettability between the phosphate coating and the oil. It is assumed that the oil retention was improved.

  In FIG. 6, the horizontal axis indicates the depth of iron phosphate, and the vertical axis indicates the amount of sliding wear. The thickness of the phosphate film in this test was 1.0 μm and the particle diameter was 3.0 μm.

  FIG. 6 shows that the amount of wear during sliding is small because the iron phosphate salt is formed at a depth of 0.5 μm from the surface of the sliding portion material. This is presumed to be a result of improving the adhesion between the sliding material and the phosphate film. Further, the weight composition of phosphorus in the iron phosphate salt is in the range of 5 to 15%, the weight composition ratio of manganese is in the range of 5 to 20%, and the weight composition ratio of iron is in the range of 70 to 85%. It was found that similar results were obtained.

  Next, characteristics of the compressor incorporating the sliding member on which the phosphate film is formed in the embodiment of the present invention will be described.

  FIG. 7 shows a characteristic comparison between the compressor using the sliding member in the embodiment of the present invention and the conventional compressor.

  The piston 119 in the embodiment of the present invention is incorporated in the compressor, and the clearance between the piston 119 and the bore 113 is the same as that of the conventional compressor.

  From FIG. 7, it can be seen that the compressor using the sliding material in the embodiment of the present invention has less variation in efficiency than the compressor of the conventional example, and the efficiency is high on average.

  In the reciprocating type compressor, when the piston 119 is located at the top dead center and the bottom dead center, the speed becomes zero and no hydraulic pressure is generated and no oil film is formed. Metal contact often occurs.

  When the piston 119 is near top dead center, the piston 119 receives a large compression load by the compressed high-pressure refrigerant, and this compression load is transmitted to the crankshaft 108 via the piston pin 121 and the connecting rod 122. Tilts in the direction of the anti-piston 119. When the crankshaft 108 is inclined, the piston 119 is inclined in the bore 113. As a result, the piston 119 comes into contact with the bore 113 and wear occurs.

  However, in this embodiment, the phosphate film 127 is controlled by controlling the film thickness and particle diameter of the phosphate film 127 and the phosphate composition at a depth of 0.5 μm from the surface of the sliding part material. The adhesion of the film 127 and the oil holding force can be increased, and the contact and wear of the piston 119 by the oil 103 with the bore 113 are reduced, so that a highly reliable compressor can be provided.

  In the embodiment of the present invention, the reciprocating compressor of a constant speed has been described. However, as the speed of the compressor is reduced along with the inverter, particularly in an ultra-low speed motion of less than 20 Hz. Since the fluid lubrication can be established, the effect of the present invention becomes remarkable.

  Further, in the embodiment of the present invention, the example in which the phosphate film 127 is formed on the surface of the sliding portion of the piston 119 has been described in detail, but the crankshaft 108 that forms the sliding portion mutually is described in detail. Slide of main shaft 109 and bearing 114, flange surface 115 and thrust washer 117 of rotor 105, thrust portion 116 and thrust washer 117 on the upper end surface of bearing 114, piston pin 121 and connecting rod 122, eccentric shaft 110 and connecting rod 122 In this part, a considerable effect can be obtained.

  Further, in the embodiment of the present invention, the thrust bearing portion 118 is configured by the flange surface 115, the thrust portion 116, and the thrust washer 117. However, the main shaft 109 and the eccentric shaft 110 of the crankshaft 108 are described. Even when a thrust bearing is constituted by the thrust surface 132 of the crankshaft 108 provided on the side opposite to the eccentric shaft 110 of the flange portion 131 and the thrust portion 116 of the bearing portion 114, a considerable effect can be obtained.

  In addition, if the refrigerant gas 102 is R600a, R290 and a mixed refrigerant including these, R134a, R152, R407C, R404A, and R410, the same effect can be obtained.

  As described above, a sliding member having high reliability can be obtained, and a highly reliable and highly efficient compressor incorporating the sliding member can be provided.

  As described above, the compressor according to the present invention enhances the adhesion between the sliding part material of the sliding part and the phosphate film, and forms a phosphate film in which the particle shape is controlled on the sliding surface. As a result, the oil retention of oil can be increased, the friction coefficient during sliding can be reduced, and a highly reliable and highly efficient compressor can be provided. Applicable.

The longitudinal cross-sectional view of the compressor in Embodiment 1 of this invention Part A enlarged view in FIG. Part B enlarged view in FIG. Relationship between film thickness and amount of wear in the same embodiment Relationship diagram between particle size and amount of wear in the same embodiment Relationship diagram between iron phosphate salt depth and wear amount in the same embodiment Characteristics of reciprocating compressor in the same embodiment Longitudinal sectional view of a conventional compressor Cross section of the main part of a conventional sliding member

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Airtight container 103 Oil 107 Compression element 108 Crankshaft 109 Main shaft 110 Eccentric shaft 112 Cylinder block 114 Bearing part 116 Thrust part 119 Piston 120 Compression chamber 121 Piston pin 122 Connecting rod 127 Phosphate film 128 Iron phosphate salt

Claims (5)

  A phosphate film is formed on the surface of the sliding part material, and at least at a depth of 0.5 μm from the surface of the sliding part material, the weight composition ratio of phosphorus is within a range of 5 to 15%. A sliding member characterized by being composed of an iron phosphate salt having a weight composition ratio of 5 to 20% and an iron weight composition ratio of 70 to 85%.   The sliding member according to claim 1, wherein the thickness of the phosphate coating is in the range of 0.5 to 2.5 µm, and the particle size of the phosphate coating is 5 µm or less.   Oil is stored in a sealed container and a compression element is accommodated. The compression element is formed integrally with the crankshaft having a main shaft and an eccentric shaft, and the other is formed integrally with the crankshaft. The thrust portion, the bearing portion that rotatably supports the main shaft, a cylinder block that forms a compression chamber, a piston that reciprocates in the compression chamber, and a piston that is arranged in parallel to the eccentric shaft. A reciprocating compression element comprising a fixed piston pin, a connecting rod connecting the eccentric shaft and the piston, and the crankshaft, the thrust part, the cylinder block, the piston, the piston pin, and the connecting rod; A compressor using the sliding member according to claim 1 or 2 at least one.   The compressor according to claim 3, wherein an oil having a viscosity grade VG of 10 or less is used.   5. The compressor according to claim 4, further comprising: an electric element that drives the compression mechanism, wherein the electric element is inverter-driven at a plurality of operation frequencies including an operation frequency that is at least a power supply frequency or less.