JP2013057287A - Sliding member and compressor - Google Patents

Abstract

The present invention provides a highly reliable sliding member that restricts the flow of oil by a V-groove structure provided on a sliding surface and has excellent slip characteristics, and a highly reliable and highly efficient compressor.
A plurality of V grooves 127 extending in a sliding direction of a piston 119 are formed on the surface of a piston 119 that is a sliding member at a predetermined interval, thereby preventing turbulent flow of oil 103 and preventing fluid from flowing. Friction could be reduced. As a result, sliding characteristics are improved, a sliding structure having excellent wear resistance is obtained, and the reliability of the compressor can be increased.
[Selection] Figure 3

Description

  The present invention provides a sliding member in which a V groove having excellent friction resistance and initial conformability is provided on a sliding surface of a steel product such as a piston, and a phosphate film is formed on the V groove structure, a refrigerator or an air The present invention relates to a compressor used for a condenser or the like.

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

  Conventionally, there have been known sliding members and compressors in which a phosphate film is formed on the sliding surface of a piston or the like of a compressor or the surface is satin-finished by shot peening to improve the initial familiarity between the sliding members. (For example, refer to Patent Document 1).

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

  FIG. 7 is a longitudinal cross-sectional view of a conventional compressor described in Patent Document 1, and FIG. 8 is a main-part cross-sectional view of a conventional sliding member described in Patent Document 1.

  As shown in FIG. 7, the hermetic 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. doing.

  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 a phosphate film 22 of porous crystal on the surface of one of the sliding portions.

  In FIG. 8, as an example of the sliding portion, a sliding portion formed by the piston 15 and the bore 12 is shown, and a porous phosphate coating 22 is formed on the sliding portion surface of the piston 15. .

  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 motion 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. As a result, the piston 15 reciprocates in the bore 12. The refrigerant gas introduced into the sealed container 1 through the suction tube 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 each sliding portion from the oil pump 10 to lubricate the sliding portion, and the sliding portion between the piston 15 and the bore 12 is a porous crystal. Oil is held by the oxide 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 variations in the shape and accuracy of the piston 15 and the bore 12, there may be a portion that causes partial contact.

  However, by forming the phosphate film 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.

International Publication No. 2007/126230

  However, when using the conventional sliding member in an environment where the viscosity of the oil is high, by taking advantage of the shape of the porous crystalline body of the phosphate film, Although oil retention could be obtained, there was a problem that sliding loss occurred because of high fluid frictional resistance due to oil viscosity.

  The present invention solves the above-described conventional problems, and provides a sliding member that improves sliding characteristics by controlling the flow of oil, and provides a highly reliable and highly efficient compressor. It is aimed.

  In order to solve the above-described conventional problems, the present invention is such that V-grooves extending in the sliding direction are arranged at regular intervals on the surface of the sliding member.

  With this configuration, the flow of oil can be controlled, and sliding loss can be reduced.

The present invention can reduce fluid resistance by controlling the turbulent flow of oil during sliding in the sliding direction. In addition, by providing a crossing groove perpendicular to the sliding direction,
The oil flowing along the V-groove collides with the oil wall accumulated in the intersecting groove, and a high-density oil film can be formed by the collision. Since the oil film improves the sealing performance of the sliding portion forming the sealed space, a highly slidable sliding member and a highly reliable and highly efficient compressor can be provided.

The longitudinal cross-sectional view of the compressor in Embodiment 1 of this invention Enlarged view of part A in FIG. Surface view of part B in FIG. Sectional view of part C in FIG. Sliding characteristic diagram in the first embodiment Characteristic diagram of reciprocating compressor in the first embodiment Vertical section of a conventional compressor Cross section of the main part of a conventional sliding member

  In the first aspect of the present invention, a plurality of V-grooves extending in the sliding direction and through which oil flows are arranged on the surface of the sliding member at a predetermined interval.

  As a result, oil turbulence during sliding can be controlled in the sliding direction, and as a result, the fluid resistance of oil can be reduced, and a highly reliable sliding member with excellent sliding characteristics can be formed. Can do.

  According to a second aspect of the present invention, in the first aspect of the present invention, a crossing groove that intersects the V-groove is provided on the surface of the sliding member.

  As a result, the oil that has flowed along the V-groove can be accumulated in the intersecting groove. As a result, the density of the oil film interposed on the sliding surface can be ensured, and a highly reliable sliding member can be configured in which a sliding configuration excellent in sealing performance by the high density oil film can be obtained.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein a phosphate film is formed on the surface of the sliding member.

  According to such a configuration, metal contact can be prevented by the porous crystal body of the phosphate film, oil retention can be increased, and wear of the sliding portion can be prevented. Therefore, a more reliable sliding member can be configured.

  According to a fourth aspect of the present invention, oil is stored in a sealed container and a compression element is accommodated, and the compression element is rotatably supported by a crankshaft having a main shaft and an eccentric shaft, and the main shaft. A bearing portion; one formed integrally with the crankshaft; the other formed integrally with the bearing portion; a cylinder block forming a cylinder; a piston reciprocating in the cylinder; and the piston The compression which uses as a reciprocating type compression element provided with the connecting rod which cooperates the piston pin fixed to the said and the said eccentric shaft and the said piston, The said piston is used as the sliding member as described in any one of Claim 1 to 3 Machine.

Accordingly, the oil resistance can be suppressed by controlling the oil by the V groove. In addition, a high-density oil film can be formed by the collision between the oil wall accumulated by the intersecting groove intersecting the sliding direction and the oil flowing along the V-groove, thereby improving the sealing performance. can do. Furthermore, since the porous crystal body by the phosphate film can prevent metal contact and increase oil retention, it is possible to provide a highly reliable compressor with excellent sliding characteristics and wear resistance. .

  The invention according to claim 5 is the invention according to claim 4, wherein the oil is an oil having a viscosity grade of VG10 or less.

  As a result, even in low-viscosity oil, the fluid resistance of the oil can be suppressed by the V groove, the cross groove, and the phosphate film on the surface of the sliding portion, and the sealing property by the oil can be improved, and the metal contact is also suppressed. A highly reliable compressor can be provided.

  The invention according to claim 6 is the invention according to claim 4 or 5, further comprising an electric element that drives the compression element, and the electric element is driven by an inverter at an operation frequency including an operation frequency at least equal to or less than the electric frequency. It is what you do.

  Accordingly, the fluid retaining state can be maintained even when the driving speed is slow due to the high oil holding force of the phosphate film on the surface of the sliding portion. Therefore, it is possible to provide a compressor having further 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 a surface view of part B in FIG. 2, and FIG. FIG. FIG. 5 is a sliding characteristic diagram according to the first embodiment, and FIG. 6 is a characteristic diagram of the reciprocating compressor.

  In FIGS. 1 to 4, the sealed container 101 is filled with a refrigerant gas 102 made of R134a, and oil 103 made of an ester of VG10 is stored at the bottom. Moreover, the electric element 106 which consists of the stator 104 and the rotor 105, and the reciprocating compression element 107 driven by this are accommodated.

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

  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, a flange surface 115 is formed on the rotor 105, 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 dimension of about 5 μm 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 side opposite to the bore 113 of the valve plate 123. 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 112, the eccentric shaft 110 and the connecting rod 122 form a sliding portion, and each sliding member At least one of them is formed with a V-shaped V-shaped groove 127 having an opening surface wider than the bottom surface in the cross-sectional shape.

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

  Among the sliding portions formed by the piston 119 and the bore 113, V-grooves 127 extending in the direction of the sliding portion are arranged at regular intervals on the sliding surface (front surface) of the piston 119. An intersection groove 128 intersecting with the V groove 127 is provided in the annular shape around the outer periphery of the piston 119 in the vicinity of the piston top portion with respect to the direction, and a phosphate film 129 that is a porous crystal is formed. .

  In the first embodiment, V grooves 127 having an opening surface of 0.3 to 0.7 mm are arranged at intervals of 0.1 to 1.0 mm, and the thickness of the phosphate film 128 is 0.5 μm or more. It is a thing.

  The operation of the reciprocating compressor in which the piston 119 having the above configuration 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. As the rotor 105 rotates, the crankshaft 108 rotates and the eccentric shaft 110 rotates. The turning motion of the eccentric shaft 110 is converted into a reciprocating motion by the connecting rod 122 which is a connecting means, and the piston 119 is driven via the piston pin 121. Therefore, the piston 119 reciprocates in the bore 113, and the refrigerant gas 102 introduced into the sealed container 101 through the suction tube 125 along with this operation is sucked from the suction muffler 126 and compressed in the compression chamber 120. Is done.

  As the crankshaft 108 rotates, the oil 103 is supplied to each sliding portion from the oil supply pump 111, lubricates the sliding portion, and plays a role of 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 the refrigeration cycle (not shown), circulates in the refrigeration cycle, and is again sealed from the suction tube 125. 101 is led.

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, the oil retention of the oil 103 can be increased by the porous crystal body formed by the phosphate film 129. As a result, 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 fluidity of the oil is improved by the V groove 127, so that the cross groove 12
8 blocks the oil flowing along the V-groove 127, thereby improving the density of the oil and providing a highly efficient and highly reliable compressor.

  The details of the efficiency as the compressor will be described later.

  Next, the angle and pitch of the V-groove 127 will be described for the sliding member in which the V-groove 127 is arranged on the surface of the sliding member at a constant interval. The sliding characteristics of the sliding member in which V-grooves 127 having a height of 0.5 mm in the sliding direction and a pitch of 0.3 to 0.7 mm are arranged at intervals of 0.3 mm on the surface of the sliding member. In a fluid friction test by sliding an iron-based test piece in the presence of a refrigerant composed of R134a and an oil composed of an ester-based VG10 at a speed of 1.0 m / s and pressing a cast iron plate at 100 N Evaluation was performed. The relationship between the width of the V-groove 127 and sliding friction will be described with reference to FIG.

  In FIG. 5, the horizontal axis represents the width of the V-groove 127, and the vertical axis represents the sliding friction coefficient. In this test, it can be seen that the sliding coefficient is improved by increasing the pitch width.

  Next, the characteristics of the compressor incorporating the sliding member (piston 119) in which the V-groove 127 is formed at regular intervals in the first embodiment of the present invention will be described.

  FIG. 6 shows a comparison of characteristics between the compressor using the sliding member in the first embodiment and the conventional compressor.

  The piston 119 in the first embodiment 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. 6, it can be seen that the compressor using the sliding material in the first embodiment of the present invention is higher in average efficiency than the conventional compressor.

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

  When the piston 119 is near top dead center, the piston 119 receives a large compressive load by the compressed high-pressure refrigerant, and this compressive 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 the first embodiment, the holding power of the oil 103 can be increased by the porous film of the phosphate film 127, and the contact and wear between the piston 119 and the bore 113 are reduced by the oil 103. . Further, the flow direction of the oil 103 is limited to the sliding direction, and a high-density oil is provided between the piston 119 and the bore 113 by the action of the cross groove 128 and the V groove 127 formed near the top portion of the piston 119. Therefore, it is possible to provide a highly reliable compressor having excellent sliding characteristics.

  Although the reciprocating compressor having a constant speed has been described in the first embodiment, the fluid lubrication is performed even in an ultra-low speed motion of less than 20 Hz as the compressor speeds down along with the inverter. Can be established, and a remarkable effect can be obtained.

In the first embodiment, the V-groove 127 is arranged on the surface of the sliding portion of the piston 119 in the sliding direction and at a constant interval, and is described in detail as an example. The main shaft 109 and the bearing portion 114 of the crankshaft 108 forming the sliding portion, or the flange surface 115 and the thrust washer 117 of the rotor 105, and the thrust portion 116 and the thrust washer 117 on the upper end surface of the bearing portion 114, In addition, the V-groove 127 and the crossing groove 128 can be similarly formed in the sliding portions formed by the piston pin 121 and the connecting rod 122, and the eccentric shaft 110 and the connecting rod 122. It can be expected.

  Further, in the first embodiment, the thrust bearing portion 118 has been described as an example configured by the flange surface 115, the thrust portion 116, and the thrust washer 117. However, the main shaft 109 and the eccentric shaft of the crankshaft 108 are described. A thrust bearing portion 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, and the V groove 127 and the intersecting groove are formed here. Even when 128 is formed, the same effect can be expected.

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

  As described above, the present invention can provide a sliding member having high reliability, and can provide a highly reliable and highly efficient compressor incorporating the sliding member.

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 121 Piston pin 122 Connecting rod 127 V groove 128 Cross groove 129 Phosphate film

Claims (6)

A sliding member in which a plurality of V-grooves extending in the sliding direction and through which oil flows are arranged on the surface of the sliding member at a predetermined interval. The sliding member according to claim 1, wherein a crossing groove that intersects with the V-groove is provided on a surface of the sliding member. The sliding member according to claim 1, wherein a phosphate film is formed on a surface of the sliding member. Oil is stored in a sealed container and a compression element is accommodated, and the compression element includes a crankshaft having a main shaft and an eccentric shaft, and a bearing portion that rotatably supports the main shaft, one of which is the crankshaft A thrust portion formed integrally with the bearing portion, a cylinder block forming a cylinder, a piston reciprocating in the cylinder, a piston pin fixed to the piston, and the eccentricity The compressor which made it the reciprocating type compression element provided with the connecting rod which cooperates a shaft and the said piston, and used the said piston as the sliding member as described in any one of Claim 1 to 3. The compressor according to claim 4, wherein the oil is an oil having a viscosity grade of VG10 or less. 6. The compressor according to claim 4, further comprising an electric element that drives the compression element, wherein the electric element is driven by an inverter at an operation frequency that includes at least an operation frequency equal to or lower than the electric frequency.