JPWO2018042507A1 - Compressor and refrigeration cycle equipment - Google Patents

Abstract

  In the compressor of the refrigeration cycle apparatus, the electric motor rotates the crankshaft. The compression mechanism compresses the refrigerant by being driven by rotation of the crankshaft. A part of the crankshaft is covered with a solid lubricant film (70). The solid lubricant film (70) contains molybdenum disulfide (71) and a resin (72). Specifically, the resin (72) is PAI (polyamideimide). The solid lubricant film (70) further includes graphite (73). The bearing of the compression mechanism is slidably fitted to a portion of the crankshaft covered with the solid lubricant film (70).

Description

  The present invention relates to a compressor and a refrigeration cycle apparatus.

  The rotary compressor described in Patent Document 1 includes a crankshaft made of mechanical structural steel. A manganese phosphate coating and a molybdenum disulfide coating are provided on the surface of the portion of the crankshaft that slides with the bearing.

JP 2009-275645 A

  In order to save energy and resources, a highly efficient compressor is required.

  If the crankshaft diameter is reduced, the sliding loss is reduced and the efficiency of the compressor can be increased. However, in a compressor that is widely used, a crankshaft having a cast material such as FCD (Ferrum Casting Ductile) 550 or FCD700 and having only a manganese phosphate coating is used. The Young's modulus of a cast material such as FCD550 or FCD700 is about 164 gigapascal. That is, the rigidity of the cast material is not high. Therefore, when the diameter of the crankshaft made of the cast material is reduced, the amount of bending of the crankshaft due to the gas load in the compression chamber increases. When the amount of bending of the crankshaft increases, the crankshaft tends to seize on the bearing, and the reliability of the compressor is impaired.

  If the material of the crankshaft is changed to a material having high rigidity, an increase in the amount of bending of the crankshaft can be suppressed. The Young's modulus of the forging material such as S45C is about 205 gigapascal or higher. That is, the forging material has high rigidity. However, the seizure strength of the crankshaft made of the forged material and the coating only of the manganese phosphate coating is inferior to the seizure resistance of the crankshaft made of the cast material and the coating only of the manganese phosphate coating by about 10%. Therefore, when the material of the crankshaft is changed from the cast material to the forged material, the crankshaft is easily seized on the bearing even if the amount of bending of the crankshaft does not increase, and the reliability of the compressor is impaired.

  Like the rotary compressor described in Patent Document 1, even if a crankshaft is used whose material is mechanical structural steel and whose coating is manganese phosphate coating and molybdenum disulfide coating, the seizure resistance of the crankshaft is not sufficiently improved. .

  An object of the present invention is to sufficiently improve the seizure resistance of a crankshaft of a compressor.

A compressor according to an aspect of the present invention is provided.
A crankshaft partially covered with a solid lubricant film containing molybdenum disulfide and a resin;
An electric motor for rotating the crankshaft;
A compression mechanism that has a bearing slidably fitted to a portion of the crankshaft covered with the solid lubricant film and that is driven by rotation of the crankshaft.

  In the present invention, a coating containing not only molybdenum disulfide but also resin is employed on the crankshaft of the compressor. For this reason, the seizure resistance of the crankshaft is sufficiently improved.

1 is a circuit diagram of a refrigeration cycle apparatus according to Embodiment 1. FIG. 1 is a circuit diagram of a refrigeration cycle apparatus according to Embodiment 1. FIG. 1 is a longitudinal sectional view of a compressor according to Embodiment 1. FIG. AA sectional drawing of FIG. Sectional drawing which shows the structure of the film in the solid lubricant application part of the crankshaft of the compressor which concerns on Embodiment 1. FIG. The graph which shows the relationship between the ratio of the film thickness with respect to a crankshaft diameter in the compressor which concerns on Embodiment 1, and the ratio of the seizing load with respect to the conventional product. The graph which shows the relationship between the ratio of the film thickness fluctuation | variation with respect to the clearance between a film and a bearing in the compressor which concerns on Embodiment 1, and the ratio of the oil film thickness with respect to the conventional product.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the part which is the same or it corresponds in each figure. In the description of the embodiments, the description of the same or corresponding parts will be omitted or simplified as appropriate. The material, shape, size, and the like of the configuration of the apparatus, instrument, component, etc. can be changed as appropriate within the scope of the present invention.

Embodiment 1 FIG.
This embodiment will be described with reference to FIGS.

*** Explanation of configuration ***
With reference to FIG. 1 and FIG. 2, the structure of the refrigerating cycle apparatus 10 which concerns on this Embodiment is demonstrated.

  FIG. 1 shows the refrigerant circuit 11 during cooling operation. FIG. 2 shows the refrigerant circuit 11 during heating operation.

  The refrigeration cycle apparatus 10 is an air conditioner in the present embodiment, but may be an apparatus other than an air conditioner such as a refrigerator or a heat pump cycle apparatus.

  The refrigeration cycle apparatus 10 includes a refrigerant circuit 11 in which a refrigerant circulates. The refrigeration cycle apparatus 10 includes a compressor 12, a four-way valve 13, a first heat exchanger 14 that is an outdoor heat exchanger, an expansion mechanism 15 that is an expansion valve, and a second heat exchanger that is an indoor heat exchanger. 16. The compressor 12, the four-way valve 13, the first heat exchanger 14, the expansion mechanism 15, and the second heat exchanger 16 are connected to the refrigerant circuit 11.

  The compressor 12 compresses the refrigerant. The four-way valve 13 switches the direction in which the refrigerant flows between the cooling operation and the heating operation. The first heat exchanger 14 operates as a condenser during the cooling operation, and dissipates the refrigerant compressed by the compressor 12. That is, the first heat exchanger 14 performs heat exchange using the refrigerant compressed by the compressor 12. The first heat exchanger 14 operates as an evaporator during the heating operation, and heats the refrigerant by exchanging heat between the outdoor air and the refrigerant expanded by the expansion mechanism 15. The expansion mechanism 15 expands the refrigerant radiated by the condenser. The second heat exchanger 16 operates as a condenser during the heating operation, and dissipates heat from the refrigerant compressed by the compressor 12. That is, the second heat exchanger 16 performs heat exchange using the refrigerant compressed by the compressor 12. The second heat exchanger 16 operates as an evaporator during the cooling operation, and heats the refrigerant by exchanging heat between the indoor air and the refrigerant expanded by the expansion mechanism 15.

  The refrigeration cycle apparatus 10 further includes a control device 17.

  Specifically, the control device 17 is a microcomputer. 1 and 2 show only the connection between the control device 17 and the compressor 12, the control device 17 is connected not only to the compressor 12 but also to elements other than the compressor 12 connected to the refrigerant circuit 11. May be. The control device 17 monitors and controls the state of elements connected to the control device 17.

  As the refrigerant circulating in the refrigerant circuit 11, HFC (HydroFluoroCarbon) refrigerants such as R32, R125, R134a, R407C, and R410A are used. Alternatively, HFO (HydroFluoroOlefin) refrigerants such as R1123, R1132 (E), R1132 (Z), R1132a, R1141, R1234yf, R1234ze (E), R1234ze (Z) are used. Alternatively, natural refrigerants such as R290 (propane), R600a (isobutane), R744 (carbon dioxide), R717 (ammonia) are used. Alternatively, other refrigerants are used. Alternatively, a mixture of two or more of these refrigerants is used.

  With reference to FIG. 3, the structure of the compressor 12 which concerns on this Embodiment is demonstrated.

  FIG. 3 shows a longitudinal section of the compressor 12.

  In the present embodiment, the compressor 12 is a hermetic compressor. Specifically, the compressor 12 is a single-cylinder rotary compressor, but may be a multi-cylinder rotary compressor, a scroll compressor, or a reciprocating compressor.

  The compressor 12 includes a sealed container 20, a compression mechanism 30, an electric motor 40, and a crankshaft 50.

  Refrigerating machine oil 25 is stored at the bottom of the sealed container 20. A suction pipe 21 for sucking the refrigerant and a discharge pipe 22 for discharging the refrigerant are attached to the sealed container 20.

  The electric motor 40 is accommodated in the sealed container 20. Specifically, the electric motor 40 is installed on the inner upper part of the sealed container 20. The electric motor 40 is a concentrated winding motor in the present embodiment, but may be a distributed winding motor.

  The compression mechanism 30 is accommodated in the sealed container 20. Specifically, the compression mechanism 30 is installed in the lower part inside the sealed container 20. That is, the compression mechanism 30 is disposed below the electric motor 40 inside the sealed container 20.

  The electric motor 40 and the compression mechanism 30 are connected by a crankshaft 50. The crankshaft 50 forms an oil supply passage for the refrigerating machine oil 25 and a rotating shaft of the electric motor 40.

  The refrigerating machine oil 25 is pumped up by an oil pump provided under the crankshaft 50 as the crankshaft 50 rotates. The refrigerating machine oil 25 is supplied to each sliding portion of the compression mechanism 30 and lubricates each sliding portion of the compression mechanism 30. As the refrigerating machine oil 25, POE (polyol ester), PVE (polyvinyl ether), AB (alkylbenzene) or the like which is a synthetic oil is used.

  The electric motor 40 rotates the crankshaft 50. The compression mechanism 30 compresses the refrigerant by being driven by the rotation of the crankshaft 50. That is, the compression mechanism 30 compresses the refrigerant by being driven by the rotational force of the electric motor 40 transmitted via the crankshaft 50. Specifically, this refrigerant is a low-pressure gas refrigerant sucked into the suction pipe 21. The high-temperature and high-pressure gas refrigerant compressed by the compression mechanism 30 is discharged from the compression mechanism 30 into the sealed container 20.

  The crankshaft 50 has an eccentric shaft portion 51, a main shaft portion 52, and a subshaft portion 53. These are provided in the order of the main shaft portion 52, the eccentric shaft portion 51, and the auxiliary shaft portion 53 in the axial direction. That is, the main shaft portion 52 is provided on one end side in the axial direction of the eccentric shaft portion 51, and the auxiliary shaft portion 53 is provided on the other end side in the axial direction of the eccentric shaft portion 51. The eccentric shaft part 51, the main shaft part 52, and the auxiliary shaft part 53 are each cylindrical. The main shaft portion 52 and the sub shaft portion 53 are provided so that their center axes coincide with each other, that is, coaxially. The eccentric shaft portion 51 is provided such that the central axis is deviated from the central axes of the main shaft portion 52 and the sub shaft portion 53. When the main shaft portion 52 and the sub shaft portion 53 rotate around the central axis, the eccentric shaft portion 51 rotates eccentrically.

  A solid lubricant is applied to a part of the crankshaft 50 to form a film. The part of the crankshaft 50 to which the solid lubricant is applied, that is, the structure of the coating film in the solid lubricant application part 37 will be described later.

  Below, the detail of the electric motor 40 is demonstrated.

  The electric motor 40 is a brushless DC (Direct Current) motor in the present embodiment, but may be a motor other than the brushless DC motor, such as an induction motor.

  The electric motor 40 includes a stator 41 and a rotor 42.

  The stator 41 has a cylindrical shape and is fixed so as to contact the inner peripheral surface of the sealed container 20. The rotor 42 has a columnar shape, and is installed inside the stator 41 via a gap having a width of 0.3 mm or more and 1.0 mm or less.

  The stator 41 has a stator core 43 and a winding 44. The stator core 43 is formed by punching a plurality of electromagnetic steel sheets mainly composed of iron and having a thickness of 0.1 mm or more and 1.5 mm or less into a certain shape, stacking them in an axial direction, and fixing them by caulking. Produced. The stator core 43 has an outer diameter larger than the inner diameter of the intermediate portion of the sealed container 20 and is fixed by being shrink-fitted inside the sealed container 20. The winding 44 is wound around the stator core 43. Specifically, the winding 44 is wound around the stator core 43 by concentrated winding via an insulating member. One end of a lead wire (not shown) is connected to the winding 44. The coil | winding 44 consists of a core wire and the at least 1 layer of film which covers a core wire. In the present embodiment, the material of the core wire is copper. The material of the coating is AI (amidoimide) / EI (ester imide). The material of the insulating member is PET (polyethylene terephthalate).

  In addition, the method of fixing the electromagnetic steel plates of the stator core 43 is not limited to caulking, and other methods such as welding may be used. The method for fixing the stator core 43 to the inside of the sealed container 20 is not limited to shrink fitting, and may be press-fitting. The material of the core wire of the winding 44 may be aluminum. The insulating member is made of PBT (polybutylene terephthalate), FEP (tetrafluoroethylene / hexafluoropropylene copolymer), PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), LCP (liquid crystal polymer), PPS (polyphenylene sulfide), or phenol resin may be used.

  The rotor 42 has a rotor core 45 and a permanent magnet (not shown). As with the stator core 43, the rotor core 45 is formed by punching a plurality of electrical steel sheets mainly composed of iron and having a thickness of 0.1 mm or more and 1.5 mm or less into a certain shape and axially. It is manufactured by laminating and fixing with caulking. The permanent magnet is inserted into a plurality of insertion holes formed in the rotor core 45. The permanent magnet forms a magnetic pole. As the permanent magnet, a ferrite magnet or a rare earth magnet is used.

  The method of fixing the electromagnetic steel plates of the rotor core 45 is not limited to caulking, and other methods such as welding may be used.

  A shaft hole into which the main shaft portion 52 of the crankshaft 50 is shrink-fitted or press-fitted is formed at the center of the rotor core 45 in plan view. That is, the inner diameter of the rotor core 45 is smaller than the outer diameter of the main shaft portion 52. Although not shown, a plurality of through holes penetrating in the axial direction are formed around the shaft hole of the rotor core 45. Each through-hole becomes one of the passages of the gas refrigerant discharged from the discharge muffler 35 described later to the space in the sealed container 20. Each through hole also serves as one of passages for dropping the refrigerating machine oil 25 guided to the upper part of the sealed container 20 to the lower part of the sealed container 20.

  Although not shown, when the motor 40 is configured as an induction motor, a plurality of slots formed in the rotor core 45 are filled or inserted with a conductor formed of aluminum, copper, or the like. Then, a squirrel-cage winding in which both ends of the conductor are short-circuited by end rings is formed.

  A terminal 24 connected to an external power source such as an inverter device is attached to the top of the sealed container 20. The terminal 24 is specifically a glass terminal. In the present embodiment, the terminal 24 is fixed to the sealed container 20 by welding. The terminal 24 is connected to the other end of the above-described lead wire. Thereby, the terminal 24 and the winding 44 of the electric motor 40 are electrically connected.

  A discharge pipe 22 having both axial ends open is further attached to the top of the sealed container 20. The gas refrigerant discharged from the compression mechanism 30 is discharged from the space in the sealed container 20 through the discharge pipe 22 to the external refrigerant circuit 11.

  Hereinafter, details of the compression mechanism 30 will be described with reference to FIG. 4 as well as FIG. 3.

  FIG. 4 shows a cut surface when the compression mechanism 30 is cut along a plane AA in FIG. 3, that is, a plane perpendicular to the axial direction of the crankshaft 50. In FIG. 4, hatching representing a cross section is omitted.

  The compression mechanism 30 includes a cylinder 31, a roller 32, a main bearing 33, a sub bearing 34, and a discharge muffler 35.

  The inner circumference of the cylinder 31 is circular in plan view. A cylinder chamber 61 that is a circular space in plan view is formed inside the cylinder 31. A suction port for sucking gas refrigerant from the refrigerant circuit 11 is provided on the outer peripheral surface of the cylinder 31. The refrigerant sucked from the suction port is compressed in the cylinder chamber 61. The cylinder 31 is open at both axial ends.

  The roller 32 has a ring shape. Therefore, the inner periphery and the outer periphery of the roller 32 are circular in plan view. The roller 32 rotates eccentrically in the cylinder chamber 61. The roller 32 is slidably fitted to an eccentric shaft portion 51 of the crankshaft 50 that serves as a rotation shaft of the roller 32.

  The cylinder 31 is provided with a vane groove 62 connected to the cylinder chamber 61 and extending in the radial direction. A back pressure chamber 63 that is a circular space in plan view connected to the vane groove 62 is formed outside the vane groove 62. A vane 64 for partitioning the cylinder chamber 61 into a suction chamber, which is a low pressure working chamber, and a compression chamber, which is a high pressure working chamber, is installed in the vane groove 62. The vane 64 has a plate shape with a rounded tip. The vane 64 reciprocates while sliding in the vane groove 62. The vane 64 is always pressed against the roller 32 by a vane spring provided in the back pressure chamber 63. Since the inside of the sealed container 20 is at a high pressure, when the operation of the compressor 12 is started, the difference between the pressure in the sealed container 20 and the pressure in the cylinder chamber 61 is formed on the back surface of the vane 64 on the back pressure chamber 63 side. The force by acts. For this reason, the vane spring is mainly used for the purpose of pressing the vane 64 against the roller 32 when the compressor 12 is started so that there is no difference in pressure between the sealed container 20 and the cylinder chamber 61.

  The main bearing 33 is a reverse T-shaped bearing in side view. The main bearing 33 is slidably fitted to a main shaft portion 52 that is a portion above the eccentric shaft portion 51 of the crankshaft 50. A through hole 54 serving as an oil supply passage is provided in the crankshaft 50 along the axial direction, and the refrigeration sucked up through the through hole 54 between the main bearing 33 and the main shaft portion 52. An oil film is formed by supplying machine oil 25. The main bearing 33 closes the upper side of the cylinder chamber 61 and the vane groove 62 of the cylinder 31. That is, the main bearing 33 closes the upper side of the two working chambers in the cylinder 31.

  The auxiliary bearing 34 is a T-shaped bearing in a side view. The auxiliary bearing 34 is slidably fitted to an auxiliary shaft portion 53 that is a portion below the eccentric shaft portion 51 of the crankshaft 50. An oil film is formed between the auxiliary bearing 34 and the auxiliary shaft portion 53 by supplying the refrigerating machine oil 25 sucked up through the through hole 54 of the crankshaft 50. The auxiliary bearing 34 closes the lower side of the cylinder chamber 61 and the vane groove 62 of the cylinder 31. That is, the auxiliary bearing 34 closes the lower side of the two working chambers in the cylinder 31.

  The main bearing 33 and the sub bearing 34 are fixed to the cylinder 31 by fasteners 36 such as bolts, respectively, and support a crankshaft 50 that is a rotating shaft of the roller 32. The main bearing 33 supports the main shaft portion 52 without contacting the main shaft portion 52 by fluid lubrication of an oil film between the main bearing 33 and the main shaft portion 52. Similar to the main bearing 33, the auxiliary bearing 34 supports the auxiliary shaft portion 53 without contacting the auxiliary shaft portion 53 by fluid lubrication of an oil film between the auxiliary bearing 34 and the auxiliary shaft portion 53.

  Although not shown, the main bearing 33 is provided with a discharge port for discharging the refrigerant compressed in the cylinder chamber 61 to the refrigerant circuit 11. The discharge port is at a position connected to the compression chamber when the cylinder chamber 61 is partitioned into the suction chamber and the compression chamber by the vane 64. The main bearing 33 is provided with a discharge valve that closes and opens the discharge port. The discharge valve is closed until the gas refrigerant in the compression chamber reaches a desired pressure, and opens when the gas refrigerant in the compression chamber reaches a desired pressure. Thereby, the discharge timing of the gas refrigerant from the cylinder 31 is controlled.

  The discharge muffler 35 is attached to the outside of the main bearing 33. The high-temperature and high-pressure gas refrigerant discharged when the discharge valve is opened once enters the discharge muffler 35 and is then discharged from the discharge muffler 35 into the space in the sealed container 20.

  The discharge port and the discharge valve may be provided in the auxiliary bearing 34 or both the main bearing 33 and the auxiliary bearing 34. The discharge muffler 35 is attached to the outside of the bearing provided with the discharge port and the discharge valve.

  A suction muffler 23 is provided beside the sealed container 20. The suction muffler 23 sucks low-pressure gas refrigerant from the refrigerant circuit 11. The suction muffler 23 prevents the liquid refrigerant from directly entering the cylinder chamber 61 of the cylinder 31 when the liquid refrigerant returns. The suction muffler 23 is connected to a suction port provided on the outer peripheral surface of the cylinder 31 via a suction pipe 21. The suction port is located at a position connected to the suction chamber when the cylinder chamber 61 is partitioned by the vane 64 into the suction chamber and the compression chamber. The main body of the suction muffler 23 is fixed to the side surface of the sealed container 20 by welding or the like.

  The material of the eccentric shaft portion 51, the main shaft portion 52, and the auxiliary shaft portion 53 of the crankshaft 50 may be a cast material, but in the present embodiment, it is a forged material such as S45C. On the other hand, the material of the main bearing 33 and the auxiliary bearing 34 is either a cast material or a sintered material, and specifically, sintered steel, gray cast iron, or carbon steel. The material of the cylinder 31 is also sintered steel, gray cast iron, or carbon steel. The material of the roller 32 is a cast material, specifically, an alloy steel containing molybdenum, nickel, and chromium, or an iron-based cast material. The material of the vane 64 is high-speed tool steel.

  Although not shown, when the compressor 12 is configured as a swing-type rotary compressor, the vane 64 is provided integrally with the roller 32. When the crankshaft 50 is driven, the vane 64 reciprocates along a groove of a support that is rotatably attached to the roller 32. The vane 64 moves back and forth in the radial direction while swinging according to the rotation of the roller 32, thereby partitioning the inside of the cylinder chamber 61 into a compression chamber and a suction chamber. The support is composed of two columnar members having a semicircular cross section. The support body is rotatably fitted in a circular holding hole formed in an intermediate portion between the suction port and the discharge port of the cylinder 31.

*** Explanation of operation ***
The operation of the compressor 12 according to the present embodiment will be described with reference to FIGS. 3 and 4. The operation of the compressor 12 corresponds to the refrigerant compression method according to the present embodiment.

  Electric power is supplied from the terminal 24 to the stator 41 of the electric motor 40 via the lead wire. As a result, a current flows through the winding 44 of the stator 41 and a magnetic flux is generated from the winding 44. The rotor 42 of the electric motor 40 rotates by the action of the magnetic flux generated from the winding 44 and the magnetic flux generated from the permanent magnet of the rotor 42. Specifically, the rotor 42 rotates due to the attractive repulsion action between the rotating magnetic field generated by the current flowing through the winding 44 of the stator 41 and the magnetic field of the permanent magnet of the rotor 42. As the rotor 42 rotates, the crankshaft 50 fixed to the rotor 42 rotates. As the crankshaft 50 rotates, the roller 32 of the compression mechanism 30 rotates eccentrically in the cylinder chamber 61 of the cylinder 31 of the compression mechanism 30. A cylinder chamber 61 that is a space between the cylinder 31 and the roller 32 is divided into a suction chamber and a compression chamber by a vane 64. As the crankshaft 50 rotates, the volume of the suction chamber and the volume of the compression chamber change. In the suction chamber, the volume gradually increases, whereby low-pressure gas refrigerant is sucked from the suction muffler 23. In the compression chamber, the gas refrigerant therein is compressed by gradually reducing the volume. The compressed, high-pressure and high-temperature gas refrigerant is discharged from the discharge muffler 35 into the space in the sealed container 20. The discharged gas refrigerant further passes through the electric motor 40 and is discharged out of the sealed container 20 from the discharge pipe 22 at the top of the sealed container 20. The refrigerant discharged to the outside of the sealed container 20 returns to the suction muffler 23 again through the refrigerant circuit 11.

*** Detailed explanation of the structure ***
The details of the solid lubricant application part 37 of the crankshaft 50 will be described with reference to FIGS.

  FIG. 5 shows a part of a cross section of the three layers of the solid lubricant film 70, the manganese phosphate film 80, and the base material 55 of the crankshaft 50.

  The solid lubricant film 70 includes molybdenum disulfide 71 and a resin 72. Specifically, the resin 72 is PAI (polyamideimide). In the present embodiment, solid lubricant film 70 further includes graphite 73.

  The resin 72 is preferably PAI, but may be PTFE, PPS, PES (polyethersulfone), PI (polyimide), or PEEK (polyetheretherketone).

  A part of the crankshaft 50 is covered with the solid lubricant film 70 having the above configuration. The main bearing 33 and the sub bearing 34 of the compression mechanism 30 are slidably fitted to the portion of the crankshaft 50 covered with the solid lubricant film 70. That is, in the present embodiment, the portion where the main bearing 33 of the main shaft portion 52 is fitted and the portion where the sub bearing 34 of the sub shaft portion 53 is fitted are the solid lubricant film having the above-described configuration. 70. By including not only molybdenum disulfide 71 but also resin 72 in solid lubricant film 70, the seizure resistance of crankshaft 50 can be sufficiently increased. Therefore, the main shaft portion 52 is difficult to seize on the main bearing 33. The auxiliary shaft portion 53 is also less likely to seize on the auxiliary bearing 34.

  As described above, in the present embodiment, the material of the main shaft portion 52 and the sub shaft portion 53 is a forged material, whereas the material of the main bearing 33 and the sub bearing 34 is either a cast material or a sintered material. However, the material of the main shaft portion 52 and the sub shaft portion 53 and the material of the main bearing 33 and the sub bearing 34 may be the same type of metal. As a specific example, both the material of the main shaft portion 52 and the sub shaft portion 53 and the material of the main bearing 33 and the sub bearing 34 may be iron-based materials. In general, when the same type of metal slides, the seizure resistance is reduced due to “co-metal”. However, in the present embodiment, the solid lubricant film 70 can suppress a decrease in the seizure resistance of the main shaft portion 52 and the sub shaft portion 53 due to “common gold”.

  In the present embodiment, the portion of the eccentric shaft portion 51 where the roller 32 is fitted is also covered with the solid lubricant film 70 having the above configuration. Therefore, the eccentric shaft portion 51 is difficult to seize on the roller 32.

  As described above, in the present embodiment, the material of the eccentric shaft portion 51 is a forged material, whereas the material of the roller 32 is a cast material. However, the material of the eccentric shaft portion 51 and the material of the roller 32 are The same kind of metal may be used. As a specific example, both the material of the eccentric shaft portion 51 and the material of the roller 32 may be an iron-based material. In the present embodiment, the solid lubricant film 70 can also suppress the seizure resistance of the eccentric shaft portion 51 due to “common gold”.

  In the present embodiment, the portion of the main shaft portion 52 that is shrink-fitted or press-fitted into the rotor core 45 is not covered with the solid lubricant film 70. Therefore, it becomes easy to shrink-fit or press-fit the main shaft portion 52 into the shaft hole of the rotor core 45.

  Although the graphite 73 is not essential, the seizure resistance of the crankshaft 50 can be further enhanced by including the graphite 73 in the solid lubricant film 70.

  In the portion of the crankshaft 50 covered with the solid lubricant film 70, the solid lubricant film 70 is overlaid on the manganese phosphate film 80. A surface 81 in contact with the solid lubricant film 70 of the manganese phosphate film 80 is an uneven surface. That is, a large number of concave portions 82 and convex portions 83 are formed on the surface 81 of the manganese phosphate coating 80. Since the surface 81 of the manganese phosphate coating 80 is not flat, the solid lubricant coating 70 tends to adhere to the surface 81 of the manganese phosphate coating 80 and is difficult to peel off. Therefore, the seizure resistance of the crankshaft 50 is further improved.

  If the roughness of the surface 81 of the manganese phosphate coating 80 in contact with the solid lubricant coating 70 is 1.5 z or more, the effect that the solid lubricant coating 70 can easily adhere to the surface 81 of the manganese phosphate coating 80 is obtained. It is done. In order to obtain a higher effect, the roughness of the surface 81 of the manganese phosphate coating 80 is desirably 2.0 z or more, and more desirably 3.0 z or more. The parameter values such as 1.5z, 2.0z, and 2.0z are values that represent the roughness of the surface 81 of the manganese phosphate coating 80 in terms of a ten-point average height.

  The manganese phosphate coating 80 is formed by subjecting the base material 55 of the crankshaft 50 to a manganese phosphate base treatment. After the manganese phosphate base treatment, when buffing is performed as in the prior art, the concave portions 82 and the convex portions 83 of the manganese phosphate coating 80 are removed, and the surface 81 of the manganese phosphate coating 80 becomes smooth. End up. Therefore, in this embodiment, buff processing is omitted. As a result, the roughness of the surface 81 of the manganese phosphate coating 80 as described above is obtained. Further, the seizure resistance of the crankshaft 50 is improved by about 70% as compared with the case where the buffing is performed after the manganese phosphate base treatment.

  The solid lubricant film 70 is formed by subjecting the manganese phosphate film 80 to a deflick coating process after the manganese phosphate base treatment. When the solid lubricant is applied by dipping, the molybdenum disulfide 71 may penetrate into the manganese phosphate coating 80. Therefore, in the present embodiment, the fixed lubricant is applied to the surface 81 of the manganese phosphate coating 80 by spraying during the deflick coating process. As a result, molybdenum disulfide 71 does not penetrate the manganese phosphate coating 80, and a solid lubricant coating 70 having the structure shown in FIG. 5 is obtained. Then, the seizure resistance of the crankshaft 50 is sufficiently improved.

  FIG. 6 shows the relationship between the ratio of the film thickness to the crankshaft diameter and the ratio of the seizure load to the conventional product.

  The “crankshaft diameter” is the diameter of the portion of the crankshaft 50 where the bearing is fitted. In the present embodiment, the diameter of the portion of the main shaft portion 52 where the main bearing 33 is fitted corresponds to the “crank shaft diameter”. The diameter of the portion of the auxiliary shaft portion 53 where the auxiliary bearing 34 is fitted also corresponds to the “crankshaft diameter”.

  The “film thickness” is the minimum thickness of the solid lubricant film 70. In the present embodiment, the main bearing 33 of the solid lubricant film 70 is opposed to the main bearing 33 from the apex of the projection 83 having the highest height of the manganese phosphate coating 80 in the portion where the main bearing 33 of the main shaft portion 52 is fitted. The distance up to the sliding surface 74 corresponds to the “film thickness”. The sliding surface 74 of the solid lubricant coating 70 facing the secondary bearing 34 from the apex of the projection 83 having the highest height of the manganese phosphate coating 80 in the portion where the secondary bearing 34 of the secondary shaft portion 53 is fitted. The distance up to this also corresponds to the “film thickness”.

  The “ratio of the film thickness to the crankshaft diameter” is a value obtained by dividing the film thickness by the crankshaft diameter.

  The “ratio of seizure load with respect to the conventional product” is the ratio of the seizure strength of the crankshaft 50 according to the present embodiment to the seizure strength of the conventional product having only the manganese phosphate coating. It is assumed that the total thickness of the solid lubricant film 70 and the manganese phosphate film 80 is the same as the thickness of the conventional film.

As shown in FIG. 6, when the ratio of the film thickness to the crankshaft diameter exceeds 0.8 × 10 ⁻³ , the ratio of the seizure load to the conventional product is less than 100%. This is because if the ratio of the film thickness to the crankshaft diameter exceeds 0.8 × 10 ⁻³ , the solid lubricant film 70 is easily peeled off. Therefore, the ratio of the film thickness to the crankshaft diameter is desirably 0.8 × 10 ⁻³ or less.

Although not shown, according to the result of the durability test, when the ratio of the film thickness to the crankshaft diameter is less than 0.3 × 10 ⁻³ , the film thickness after operating the compressor 12 for a long period of time such as 10 years. Is not enough. This is because the amount of wear of the solid lubricant film 70 increases as the period of operation of the compressor 12 increases. Therefore, it is desirable that the ratio of the film thickness to the crankshaft diameter is 0.3 × 10 ⁻³ or more.

  As described above, the solid lubricant film 70 with respect to the diameter of the main shaft portion 52 in the portion where the main bearing 33 of the main shaft portion 52 is fitted, in order to prevent the seizure strength from being lowered due to peeling and abrasion of the solid lubricant film 70. The minimum thickness ratio is preferably 0.0003 or more and 0.0008 or less. Also in the portion of the auxiliary shaft portion 53 where the auxiliary bearing 34 is fitted, the ratio of the minimum thickness of the solid lubricant film 70 to the diameter of the auxiliary shaft portion 53 is preferably 0.0003 or more and 0.0008 or less. .

  FIG. 7 shows the relationship between the ratio of film thickness variation to the clearance between the coating and the bearing and the ratio of oil film thickness to the conventional product.

  “Clear between coating and bearing” refers to the distance between the solid lubricant coating 70 and the bearing. In the present embodiment, the maximum value of the distance between the solid lubricant film 70 and the main bearing 33 corresponds to the “clearance between the film and the bearing”. The maximum value of the distance between the solid lubricant film 70 and the auxiliary bearing 34 also corresponds to the “clearance between the film and the bearing”.

  The “film thickness variation” is a difference in height of the sliding surface 74 facing the bearing of the solid lubricant film 70. In the present embodiment, from the outer peripheral surface of the base 55 of the main shaft portion 52 to the sliding surface 74 of the solid lubricant film 70 facing the main bearing 33 in the portion where the main bearing 33 of the main shaft portion 52 is fitted. The difference between the maximum value and the minimum value of the distance corresponds to the “film thickness variation”. The maximum distance from the outer peripheral surface of the base 55 of the auxiliary shaft 53 to the sliding surface 74 of the solid lubricant film 70 facing the auxiliary bearing 34 in the portion where the auxiliary bearing 34 of the auxiliary shaft 53 is fitted. The difference between the value and the minimum value corresponds to “film thickness variation”.

  The “ratio of film thickness variation to the clearance between the coating and the bearing” is a value obtained by dividing the variation in film thickness by the clearance between the coating and the bearing.

  “The ratio of the oil film thickness to the conventional product” refers to the distance between the main bearing 33 and the main shaft portion 52 in the crankshaft 50 according to the present embodiment with respect to the thickness of the oil film in the conventional product having only the manganese phosphate coating. Or the ratio of the thickness of the oil film between the auxiliary bearing 34 and the auxiliary shaft portion 53.

  As shown in FIG. 7, when the ratio of the film thickness variation to the clearance between the coating and the bearing exceeds 0.15, the ratio of the oil film thickness to the conventional product is less than 1.0. This is because if the ratio of the variation in film thickness to the clearance between the coating and the bearing exceeds 0.15, the gap between the solid lubricant coating 70 and the bearing is too wide to form an oil film. is there. Therefore, it is desirable that the ratio of film thickness variation to the clearance between the coating and the bearing is 0.15 or less.

  As described above, in order to ensure a sufficient oil film thickness and prevent a decrease in sliding strength, the portion of the main shaft portion 52 where the main bearing 33 is fitted is formed between the solid lubricant film 70 and the main bearing 33. The ratio of the height difference of the sliding surface 74 facing the main bearing 33 of the solid lubricant film 70 with respect to the clearance between them is preferably 0.15 or less. Even in the portion where the auxiliary bearing 34 of the auxiliary shaft portion 53 is fitted, the height of the sliding surface 74 of the solid lubricant film 70 facing the auxiliary bearing 34 with respect to the clearance between the solid lubricant film 70 and the auxiliary bearing 34 is high. The difference ratio is desirably 0.15 or less.

*** Explanation of the effect of the embodiment ***
In the present embodiment, a coating including not only molybdenum disulfide 71 but also resin 72 is employed on the crankshaft 50 of the compressor 12. For this reason, the seizure resistance of the crankshaft 50 is sufficiently improved. Specifically, the seizure resistance of the crankshaft 50 is improved by about 10% to 20% over the conventional product. Therefore, even if a forged material is used as the material of the crankshaft 50, the crankshaft 50 is difficult to seize on the bearing. Therefore, the diameter of the crankshaft 50 can be reduced without impairing the reliability of the compressor 12, and the highly efficient compressor 12 can be obtained.

  A large amount of liquid refrigerant flows into the sealed container 20 of the compressor 12, and the viscosity of the refrigerating machine oil 25 decreases, and between the main shaft portion 52 and the main bearing 33 and between the sub shaft portion 53 and the sub bearing 34. The oil film thickness may be significantly reduced. In the present embodiment, even in such a case, the crankshaft 50 is not seized, and the highly reliable compressor 12 can be obtained.

*** Other configurations ***
The solid lubricant film 70 may further include a different type of resin from the resin 72. Specifically, the solid lubricant film 70 may contain two or more kinds of resins among PAI, PTFE, PPS, PES, PI, and PEEK.

  As described above, the compressor 12 may be a multi-cylinder rotary compressor. Here, an example in which the compressor 12 is configured as a multi-cylinder rotary compressor will be described as a modification of the present embodiment.

  Although not illustrated, in this modification, the compression mechanism 30 includes a plurality of cylinders 31, a plurality of rollers 32, and a number of partition plates that is one less than the number of cylinders 31. If the number of cylinders 31 is two, the number of rollers 32 is two and the number of partition plates is one.

  The crankshaft 50 has the same number of eccentric shaft portions 51 as the number of rollers 32. A corresponding roller 32 is slidably fitted to each eccentric shaft portion 51. The shaft diameter of the portion between the plurality of eccentric shaft portions 51 is approximately the same as the diameter of the main shaft portion 52.

  A cylinder chamber 61 that is a circular space in a plan view is formed inside each cylinder 31. Each roller 32 rotates eccentrically in the corresponding cylinder chamber 61. That is, the compression mechanism 30 is formed with a plurality of cylinder chambers 61 that are spaces for compressing the refrigerant. The plurality of cylinder chambers 61 are partitioned in the axial direction of the crankshaft 50 by a partition plate. That is, the partition plate closes the cylinder chamber 61 directly above the partition plate and the cylinder chamber 61 directly below the partition plate.

  The partition plate may be composed of a single plate through which the crankshaft 50 passes. In this case, the partition plate extends from one end in the axial direction of the crankshaft 50 to a portion between the plurality of eccentric shaft portions 51. If it does not pass through the through hole, the partition plate cannot be installed at a desired position. In other words, the partition plate must be formed with a through hole having a size that allows the eccentric shaft portion 51 on the side close to one end of the crankshaft 50 in the axial direction to pass therethrough. On the other hand, in this modification, the partition plate is composed of a plurality of divided plates arranged around the crankshaft 50. Therefore, if a portion between the plurality of eccentric shaft portions 51 is surrounded by a plurality of divided plates and the divided plates are fixed with a fixing tool such as a bolt, the partition plate can be installed at a desired position. That is, it is only necessary that the partition plate be formed with a through-hole having a size capable of passing a portion between the plurality of eccentric shaft portions 51. Each divided plate is provided with a notch corresponding to a part of a through hole formed when all divided plates are combined. If the number of divided plates is two, a donut-shaped partition plate in which circular through-holes are formed by combining semi-circular divided plates each having a small semi-circular cutout in a straight portion. Will be configured.

  Also in this modified example, a film including not only molybdenum disulfide 71 but also resin 72 is employed on the crankshaft 50 of the compressor 12. Therefore, as described above, the diameter of the crankshaft 50 can be reduced without impairing the reliability of the compressor 12, and the highly efficient compressor 12 can be obtained. Specifically, reducing the diameter of the crankshaft 50 means reducing the diameter of the main shaft portion 52 without changing the diameter of the eccentric shaft portion 51, that is, increasing the amount of eccentricity. Even if the diameter of the eccentric shaft portion 51 is increased without changing the diameter of the main shaft portion 52, the amount of eccentricity increases. In this modification, since the partition plate is divided, it is not necessary to change the size of the through hole of the partition plate even if the diameter of the eccentric shaft portion 51 is increased. Therefore, a situation in which the through hole of the partition plate is too large and the partition plate cannot close the cylinder chamber 61 can be avoided. Therefore, the amount of eccentricity can be increased without impairing the reliability of the compressor 12, and a highly efficient compressor 12 can be obtained.

  As mentioned above, although embodiment of this invention was described, you may implement this embodiment partially. In addition, this invention is not limited to this embodiment, A various change is possible as needed.

  DESCRIPTION OF SYMBOLS 10 Refrigeration cycle apparatus, 11 Refrigerant circuit, 12 Compressor, 13 Four-way valve, 14 1st heat exchanger, 15 Expansion mechanism, 16 2nd heat exchanger, 17 Control apparatus, 20 Airtight container, 21 Intake pipe, 22 Discharge pipe , 23 Suction muffler, 24 terminals, 25 Refrigerating machine oil, 30 Compression mechanism, 31 Cylinder, 32 Roller, 33 Main bearing, 34 Sub bearing, 35 Discharge muffler, 36 Fastener, 37 Solid lubricant application part, 40 Electric motor, 41 Fixed 42, rotor, 43 stator core, 44 windings, 45 rotor core, 50 crankshaft, 51 eccentric shaft, 52 main shaft, 53 subshaft, 54 through hole, 55 base, 61 cylinder chamber, 62 vane groove, 63 back pressure chamber, 64 vane, 70 solid lubricant film, 71 molybdenum disulfide, 72 resin, 73 graphite, 74 sliding surface, 8 Manganese phosphate film, 81 surface, 82 recess, 83 projection portion.

Claims (13)

A crankshaft partially covered with a solid lubricant film containing molybdenum disulfide and a resin;
An electric motor for rotating the crankshaft;
A compressor having a bearing slidably fitted in a portion of the crankshaft covered with the solid lubricant film and driven by rotation of the crankshaft.   The compressor according to claim 1, wherein the resin is polyamideimide.   The compressor according to claim 1, wherein the solid lubricant film further includes graphite.   In the portion of the crankshaft covered with the solid lubricant film, the solid lubricant film is overlaid on the manganese phosphate film, and the surface of the manganese phosphate film in contact with the solid lubricant film is The compressor according to any one of claims 1 to 3, wherein the compressor has an uneven surface.   The compressor according to claim 4, wherein a surface roughness of the manganese phosphate coating in contact with the solid lubricant coating is 1.5z or more.   The compressor according to claim 4, wherein a surface roughness of the manganese phosphate coating in contact with the solid lubricant coating is 2.0z or more.   The compressor according to claim 4, wherein the surface of the manganese phosphate coating in contact with the solid lubricant coating has a roughness of 3.0z or more.   8. The ratio of the minimum thickness of the solid lubricant film to the diameter of the crankshaft in a portion of the crankshaft where the bearing is fitted is 0.0003 or more and 0.0008 or less. The compressor according to item.   In the portion of the crankshaft where the bearing is fitted, the ratio of the height difference of the sliding surface of the solid lubricant coating facing the bearing to the clearance between the solid lubricant coating and the bearing is 0.15. The compressor according to any one of claims 1 to 8, which is: The crankshaft has a main shaft portion and a sub shaft portion provided coaxially,
The bearing is slidably fitted to each of the main shaft portion and the sub shaft portion,
The portions where the bearings of the main shaft portion and the sub shaft portion are fitted are covered with the solid lubricant film,
The compressor according to any one of claims 1 to 9, wherein a material of the main shaft portion and the sub shaft portion is a forged material, whereas a material of the bearing is either a cast material or a sintered material. . The crankshaft has an eccentric shaft portion that rotates eccentrically,
The compression mechanism has a roller slidably fitted to the eccentric shaft portion,
The portion of the eccentric shaft portion where the roller is fitted is covered with the solid lubricant film,
The compressor according to any one of claims 1 to 10, wherein a material of the eccentric shaft portion is a forged material, whereas a material of the roller is a cast material. The compression mechanism is a space for compressing the refrigerant, and is formed with a plurality of cylinder chambers partitioned by a partition plate in the axial direction of the crankshaft.
The compressor according to any one of claims 1 to 10, wherein the partition plate includes a plurality of divided plates arranged around the crankshaft.   A refrigeration cycle apparatus comprising the compressor according to any one of claims 1 to 12.

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