Compressor and Method for Exchanging Oil in Compressor

Abstract

To provide a compressor which enables easy removal of foreign objects existing at a lower part of an internal space of a casing during oil replacement, and to provide an oil replacement method of the compressor.SOLUTION: A scroll compressor 100 includes: a compression mechanism 20; a casing 10; a first pipe 212; and a second pipe 222 different from the first pipe. The casing houses the compression mechanism. The first pipe is disposed penetrating through the casing and recovers oil from a lower part of an internal space S of the casing. The second pipe is disposed penetrating through the casing and fills the internal space of the casing with the oil. In an oil replacement method of the scroll compressor, the first pipe is utilized to recover the oil and the second pipe is utilized to fill the internal space with the oil.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a compressor and a method for changing oil in the compressor.

Background Art

[0002] Conventionally, as disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-103115), there is known a compressor in which a refrigerating machine oil for lubrication is stored in a lower part of an internal space of a casing of the compressor.

[0003] The oil used in the compressor may deteriorate over time. Further, foreign substances (for example, decomposition products of oil, wear powder generated at a sliding part of the compressor, etc.) may be mixed into the oil used in the compressor. Therefore, there are cases where the oil is recovered from the internal space of the compressor, and new oil is filled, or the oil is refilled after removing foreign substances. Therefore, as in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-103115), there are cases where a pipe for recovering and filling oil is provided in the compressor.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when a single pipe is provided in the compressor as in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-103115), and both oil recovery and filling are performed with this pipe, the present inventors have found that there is a possibility that foreign substances in the lower part of the internal space of the casing where the oil is stored cannot be sufficiently removed.

Means for Solving the Problems

[0005] The compressor according to the first aspect includes a compression mechanism, a casing, a first pipe, and a second pipe different from the first pipe. The casing houses the compression mechanism. The first pipe is disposed to penetrate the casing and recovers oil from a lower part of the internal space of the casing. The second pipe is disposed to penetrate the casing and fills the internal space of the casing with oil.

[0006] In the compressor of the first aspect, by using separate pipes for the first pipe for recovering oil and the second pipe for filling oil, the removal rate of foreign matter present in the space where oil accumulates at the lower part of the casing can be increased compared to the case of using a single pipe for oil recovery and filling.

[0007] The compressor of the second aspect is the compressor of the first aspect, and further includes a pumping mechanism and a filter. The pumping mechanism pumps oil from the lower part of the internal space of the casing. The filter covers the oil intake port of the pumping mechanism from the lower part of the internal space of the casing. By filling oil from the second pipe, foreign matter attached to the filter is removed.

[0008] In the compressor of the second aspect, foreign matter attached to the filter, which is difficult to remove when using a single pipe for oil recovery and filling, can be removed when filling oil from the second pipe.

[0009] The compressor of the third aspect is the compressor of the second aspect, and the oil discharge port of the second pipe faces the filter.

[0010] In the compressor of the third aspect, since the oil discharge port of the second pipe is directed toward the filter, it is easy to remove foreign matter attached to the filter with the oil discharged from the second pipe.

[0011] The compressor of the fourth aspect is the compressor of the third aspect, and the second pipe includes a first portion. The first portion extends downward toward the discharge port.

[0012] In the compressor of the fourth aspect, since the second pipe includes the first portion, it is easy to remove foreign matter attached to the filter with the oil discharged from the second pipe.

[0013] The compressor of the fifth aspect is the compressor of the third or fourth aspect, and the second pipe includes a nozzle portion. The nozzle portion extends between the first end and the second end where the discharge port is disposed. In the nozzle portion, the flow path area of the oil gradually decreases from the first end toward the second end.

[0014] In the compressor of the fifth aspect, since the second pipe has a nozzle portion, it is easy to remove foreign matter adhering to the filter with the flow of oil discharged from the second pipe.

[0015] The compressor of the sixth aspect is any one of the compressors from the first aspect to the fifth aspect, and the end portion where the oil suction port of the first pipe is provided is arranged near the bottom surface of the casing.

[0016] In the present disclosure, since a second pipe different from the first pipe is used for oil filling, a structure and arrangement particularly suitable for oil recovery can be adopted for the structure and arrangement of the first pipe. Specifically, in the compressor of the sixth aspect, since the suction port of the first pipe is arranged near the bottom surface of the casing, it is easy to remove foreign matter deposited on the bottom surface of the casing during oil recovery.

[0017] The compressor of the seventh aspect is any one of the compressors from the first aspect to the sixth aspect, and the oil suction port of the first pipe faces the bottom surface of the casing.

[0018] In the compressor of the seventh aspect, since the suction port of the first pipe is directed toward the bottom surface of the casing, it is easy to remove foreign matter accumulated on the bottom surface of the casing during oil recovery.

[0019] The compressor of the eighth aspect is any one of the compressors from the first aspect to the seventh aspect, and the second pipe functions as an oil equalizing pipe with other compressors.

[0020] In the compressor of the eighth aspect, by also using the second pipe as an oil equalizing pipe, the number of parts can be reduced compared to the case where an oil equalizing pipe is further provided separately from the first pipe and the second pipe.

[0021] The method for exchanging oil in the compressor according to the ninth aspect is the method for exchanging oil in any one of the compressors according to the first to eighth aspects. The method for exchanging oil in a compressor includes a first step, a second step, a third step, and a fourth step. In the first step, the internal space of the casing is filled with gas and the internal pressure is increased. In the second step, due to the pressure difference between the internal space of the casing and the outside of the casing, oil is recovered from the lower part of the internal space of the casing through the first pipe. In the third step, the internal space of the casing is evacuated. In the fourth step, oil is filled into the internal space of the casing through the second pipe.

[0022] In the method for exchanging oil in the compressor according to the ninth aspect, the removal rate of foreign substances present in the space where the oil accumulates at the lower part of the internal space of the casing can be increased as compared with the case of using a single pipe for oil recovery and filling.

[0023] The method for exchanging oil in the compressor according to the tenth aspect is the method for exchanging oil according to the ninth aspect, and the first to fourth steps are repeatedly executed.

[0024] In the method for exchanging oil in the compressor according to the tenth aspect, the removal rate of foreign substances present in the space where the oil accumulates at the lower part of the casing can be particularly increased.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0026] Embodiments of the compressor of the present disclosure will be described with reference to the drawings. (1) Refrigeration cycle device With reference to FIG. 1, an example of a refrigeration cycle device having the compressor of the present disclosure will be described. FIG. 1 is a schematic configuration diagram of a refrigeration cycle device 1 having a scroll compressor 100. The scroll compressor 100 is an example of the compressor of the present disclosure. The refrigeration cycle device 1 is an example of a refrigeration cycle device having the compressor of the present disclosure.

[0027] The refrigeration cycle device 1 is a device that performs heating or cooling of an object to be temperature-adjusted using a vapor compression refrigeration cycle. Although the application is not limited, the refrigeration cycle device 1 includes, for example, an air conditioner, a water heater, and a floor heating device. The scroll compressor 100 constitutes a part of the refrigerant circuit 7 of the refrigeration cycle device 1. The scroll compressor 100 is mounted, for example, on the heat source unit of the refrigeration cycle device 1. In the heat source unit, the scroll compressor 100, a heat exchanger, an expansion mechanism, etc. are housed in a housing.

[0028] An overview of the refrigeration cycle device 1 will be described.

[0029] The refrigeration cycle device 1 of the present embodiment is an air conditioner dedicated to cooling. The refrigeration cycle device 1 mainly includes a scroll compressor 100, a first heat exchanger 2, an expansion mechanism 3, and a second heat exchanger 4. The scroll compressor 100, the first heat exchanger 2, the expansion mechanism 3, and the second heat exchanger 4 are connected by pipes to form a refrigerant circuit 7. Further, the refrigeration cycle device 1 has a control unit (not shown) that controls the operations of the scroll compressor 100 and the expansion mechanism 3.

[0030] Note that the refrigeration cycle device 1 may have a configuration other than that exemplified here, for example, a flow direction switching mechanism for switching the flow direction of the refrigerant to enable heating operation, a heat exchanger for subcooling the refrigerant discharged from the first heat exchanger 2, an accumulator having a gas-liquid separation function, and the like.

[0031] The refrigerant filled in the refrigerant circuit 7 (the refrigerant compressed by the scroll compressor 100) is, for example, R32, an HFC refrigerant. Note that R32 is merely an example of the type of refrigerant, and the refrigerant filled in the refrigerant circuit 7 may be an HFC refrigerant other than R32 or an HFO refrigerant. Further, the refrigerant filled in the refrigerant circuit 7 may be a natural refrigerant such as carbon dioxide, for example.

[0032] The scroll compressor 100 is a device that sucks and compresses the low-pressure refrigerant (hereinafter, may be simply referred to as low pressure) in the refrigeration cycle from the first pipe 7a and discharges the high-pressure refrigerant (hereinafter, may be simply referred to as high pressure) in the refrigeration cycle after compression from the second pipe 7b. The first pipe 7a is a refrigerant pipe that guides the refrigerant discharged from the second heat exchanger 4 to the suction pipe 18a of the scroll compressor 100. The second pipe 7b is a refrigerant pipe that guides the refrigerant discharged from the discharge pipe 18b of the scroll compressor 100 to the first heat exchanger 2. Details of the scroll compressor 100 will be described later.

[0033] The first heat exchanger 2 functions as a radiator (condenser) of the refrigerant that dissipates heat from the refrigerant discharged by the scroll compressor 100 by exchanging heat with water or air as a heat source. At one end of the first heat exchanger 2, the second pipe 7b that communicates the discharge pipe 18b of the scroll compressor 100 and the first heat exchanger 2 is connected. At the other end of the first heat exchanger 2, the third pipe 7c that communicates the first heat exchanger 2 and the second heat exchanger 4 is connected.

[0034] The expansion mechanism 3 is a mechanism that reduces the pressure of the refrigerant that has dissipated heat in the first heat exchanger 2. The expansion mechanism 3 is an electronically controlled expansion valve with variable opening. However, it is not limited to this, and the expansion mechanism 3 may be a thermostatic automatic expansion valve or a capillary tube. The expansion mechanism 3 is disposed in the third pipe 7c.

[0035] The second heat exchanger 4 functions as an evaporator that heats the refrigerant by causing heat exchange between the refrigerant cooled by the first heat exchanger 2 and decompressed by the expansion mechanism 3 and the object to be temperature-controlled (here, air). When the refrigerant is heated in the second heat exchanger 4, the air to be temperature-controlled is cooled. One end of the second heat exchanger 4 is connected to a third pipe 7c that communicates the first heat exchanger 2 and the second heat exchanger 4. The other end of the second heat exchanger 4 is connected to a first pipe 7a that communicates the suction pipe 18a of the scroll compressor 100 and the second heat exchanger 4.

[0036] Also, a shut-off valve 6 (three-way valve) with a service port is used in the first pipe 7a, and a shut-off valve 5 (three-way valve) with a service port is used in the third pipe 7c. The service ports of the shut-off valves 5 and 6 are used when filling the refrigerant circuit 7 with refrigerant or recovering the refrigerant in the refrigerant circuit 7. Further, the service ports of the shut-off valves 5 and 6 are also used when evacuating or filling a gas (nitrogen gas) into at least a part of the refrigerant circuit 7 including the internal space S of the casing 10 of the scroll compressor 100 described later. Note that the positions and structures of the refrigerant shut-off valves 5 and 6 in the refrigerant circuit 7 are not particularly limited as long as they can be used for these applications.

[0037] (2) Scroll Compressor Hereinafter, in addition to FIG. 1, the scroll compressor 100 will be described with reference to FIG. 2. FIG. 2 is a schematic longitudinal sectional view of the scroll compressor 100.

[0038] Hereinafter, for the sake of convenience of explanation, expressions such as "up" and "down" may be used to explain the position and orientation. Unless otherwise specified, the position and orientation represented by expressions such as "up" and "down" follow the arrows in the figure.

[0039] In addition, in the following, expressions such as "parallel", "orthogonal", "horizontal", "vertical", "identical", etc. may be used, but these expressions are not limited to the case where they are "parallel", "orthogonal", "horizontal", "vertical", "identical" in a strict sense. Expressions such as "parallel", "orthogonal", "horizontal", "vertical", "identical", etc. are used in a meaning that includes the case where they are substantially "parallel", "orthogonal", "horizontal", "vertical", "identical".

[0040] The scroll compressor 100 of the present disclosure is a fully enclosed compressor. As shown in FIGS. 1 and 2, the scroll compressor 100 mainly includes a casing 10, a compression mechanism 20, a housing 50, a motor 70, a drive shaft 80, a lower bearing housing 90, an oil recovery section 210, and an oil filling section 220.

[0041] (2-1) Casing The scroll compressor 100 has a vertically long cylindrical casing 10 (see FIG. 2). The casing 10 forms an internal space S inside thereof.

[0042] The casing 10 mainly includes a cylindrical portion 12 as an example of a cylindrical portion, an upper lid 14a, and a lower lid 14b.

[0043] The cylindrical portion 12 is a cylindrical member that extends along the central axis O and has openings at both ends. In the scroll compressor 100 of the present embodiment, the central axis O extends in the vertical direction.

[0044] The upper lid 14a is provided above the cylindrical portion 12 and closes the upper opening of the cylindrical portion 12. The lower lid 14b is provided below the cylindrical portion 12 and closes the lower opening of the cylindrical portion 12. The cylindrical portion 12, the upper lid 14a, and the lower lid 14b are fixed, for example, by welding so as to maintain airtightness.

[0045] The casing 10 houses various components and members that constitute the scroll compressor 100 inside. The components and members housed in the casing 10 include the compression mechanism 20, the housing 50, the motor 70, the drive shaft 80, and the lower bearing housing 90 (see FIG. 2).

[0046] As shown in Fig. 2, a compression mechanism 20 is disposed at the upper part inside the casing 10. A housing 50 is disposed below the compression mechanism 20. A motor 70 is disposed below the housing 50. A lower bearing housing 90 is disposed below the motor 70. An oil reservoir space 16 is formed at the lower part of the internal space S of the casing 10. Oil (refrigerant oil) for lubricating various sliding parts of the scroll compressor 100 is stored in the oil reservoir space 16.

[0047] The motor 70 is disposed in a first space S1 below the housing 50 in the internal space S of the casing 10. In the scroll compressor 100 of the present embodiment, the first space S1 is a space into which high-pressure refrigerant compressed by the compression mechanism 20 flows. In other words, the scroll compressor 100 of the present embodiment is a so-called high-pressure dome type scroll compressor. The space between the housing 50 and the motor 70 communicates with the oil reservoir space 16 at the lower part of the casing 10 through a gap between the cylindrical portion 12 and the stator 72 of the motor 70 described later, a gap between the stator 72 and the rotor 74 of the motor 70 described later, etc. (see Fig. 2).

[0048] Note that the scroll compressor 100 does not have to be a high-pressure dome type scroll compressor. The scroll compressor 100 may be a so-called low-pressure dome type scroll compressor in which the motor 70 is disposed in a space into which low-pressure refrigerant flows from the refrigerant circuit 7 of the refrigeration cycle apparatus 1.

[0049] An intake pipe 18a, a discharge pipe 18b, a first pipe 212 of the oil recovery part 210, and a second pipe 222 of the oil filling part 220 are attached to the casing 10 so as to communicate the inside and the outside of the casing 10 (see Fig. 2).

[0050] As shown in Fig. 2, the suction pipe 18a is provided through the upper lid 14a of the casing 10. One end of the suction pipe 18a (the end outside the casing 10) is connected to the first pipe 7a of the refrigeration cycle device 1 as shown in Fig. 2. The other end of the suction pipe 18a (the end inside the casing 10) is connected to the suction hole 36a of the fixed scroll 30 of the compression mechanism 20 as shown in Fig. 2. The suction pipe 18a communicates with the compression chamber Sc on the outer peripheral side of the compression mechanism 20 described later through the suction hole 36a. The scroll compressor 100 sucks the low-pressure refrigerant in the refrigeration cycle of the refrigeration cycle device 1 through the suction pipe 18a.

[0051] As shown in Fig. 2, the discharge pipe 18b is provided through the central portion of the cylindrical portion 12 in the vertical direction and penetrates the cylindrical portion 12. One end of the discharge pipe 18b (the end outside the casing 10) is connected to the second pipe 7b of the refrigeration cycle device 1 as shown in Fig. 2. The other end of the discharge pipe 18b (the end inside the casing 10) is disposed in the space between the housing 50 and the motor 70. The scroll compressor 100 discharges the high-pressure refrigerant after compression by the compression mechanism 20 to the outside of the scroll compressor 100 through the discharge pipe 18b.

[0052] As shown in Fig. 2, the first pipe 212 of the oil recovery unit 210 is disposed through the lower lid 14b of the casing 10. The first pipe 212 is a pipe for recovering oil from the lower part (oil sump space 16) of the internal space S of the casing 10. The oil recovery unit 210 will be described later.

[0053] As shown in Fig. 2, the second pipe 222 of the oil filling unit 220 is disposed through the lower lid 14b of the casing 10. The second pipe 222 is a pipe for filling oil into the internal space S of the casing 10. The oil filling unit 220 will be described later.

[0054] (2-2) Compression mechanism The compression mechanism 20 mainly includes a fixed scroll 30 and a movable scroll 40. The fixed scroll 30 and the movable scroll 40 are combined to form a compression chamber Sc. The compression mechanism 20 compresses the refrigerant in the compression chamber Sc and discharges the compressed refrigerant.

[0055] (2-2-1) Fixed scroll The fixed scroll 30 is fixed on the housing 50.

[0056] As shown in Fig. 2, the fixed scroll 30 mainly includes a first mirror plate 32, a first lap 34 protruding from the front surface 32a of the first mirror plate 32 toward the movable scroll 40 side, and a peripheral edge portion 36 arranged to surround the periphery of the first lap 34. When looking at the fixed scroll 30 from below, the first lap 34 is formed in a spiral (involute shape) from near the center of the first mirror plate 32 toward the outer peripheral side. Suction holes 36a are formed in the peripheral edge portion 36. The downstream end of the suction pipe 18a is connected to the suction holes 36a.

[0057] The first lap 34 of the fixed scroll 30 and the second lap 44 of the movable scroll 40 described later are combined to form a compression chamber Sc. When the movable scroll 40 rotates relative to the fixed scroll 30, the low-pressure refrigerant flowing into the peripheral compression chamber Sc from the suction pipe 18a through the suction holes 36a is compressed as it moves to the central compression chamber Sc, and the pressure rises.

[0058] A discharge port 33 for discharging the refrigerant compressed by the compression mechanism 20 is formed through the first mirror plate 32 in the thickness direction (vertical direction) at approximately the center of the first mirror plate 32 (see Fig. 2). The discharge port 33 communicates with the central (innermost) compression chamber Sc of the compression mechanism 20. The refrigerant compressed by the compression mechanism 20 and discharged from the discharge port 33 flows into the space below the housing 50 through the refrigerant passage.

[0059] (2-2-2) Movable scroll As shown in FIG. 2, the movable scroll 40 mainly includes a second mirror plate 42, a second wrap 44 that protrudes from the front surface 42a of the second mirror plate 42 toward the fixed scroll 30, and a cylindrical boss portion 46. When viewing the movable scroll 40 from above, the second wrap 44 is formed in a spiral (involute shape) from near the center of the second mirror plate 42 toward the outer peripheral side. The boss portion 46 is a cylindrical portion that protrudes from the back surface 42b of the second mirror plate 42 toward the motor 70 side.

[0060] The boss portion 46 is disposed in a crank chamber 52, which will be described later, formed by the housing 50. A bearing metal 47 is disposed in the hollow portion of the boss portion 46. An eccentric portion 84 of a drive shaft 80, which will be described later, is inserted into the hollow portion of the boss portion 46 (see FIG. 2).

[0061] (2-3) Housing As shown in FIG. 2, the housing 50 mainly includes a main body portion 120 and an upper bearing housing 110 in which a rolling bearing 112 for rotatably supporting the drive shaft 80 is disposed inside. The main body portion 120 is a cylindrical portion. The upper bearing housing 110 is also formed in a cylindrical shape. The upper bearing housing 110 is disposed closer to the motor 70 than the main body portion 120 in the axial direction of the drive shaft 80.

[0062] The main body portion 120 of the housing 50 is fixed to the inner peripheral surface 12a of the cylindrical portion 12 of the casing 10. The fixed scroll 30 is fixed to the main body portion 120 of the housing 50. Specifically, the fixed scroll 30 is placed on the housing 50 in a state where the lower surface of the peripheral edge portion 36 of the fixed scroll 30 faces the upper surface of the housing 50, and is fixed to the housing 50 by a fixing member (for example, a bolt) not shown. The housing 50 supports the fixed scroll 30 fixed to the main body portion 120.

[0063] Further, the housing 50 supports the movable scroll 40 disposed between the fixed scroll 30 and the main body portion 120 of the housing 50. Specifically, the housing 50 supports the movable scroll 40 from below via an Oldham coupling 24 disposed above the housing 50.

[0064] As shown in FIG. 2, the main body portion 120 of the housing 50 has a first recess 56 that is arranged to be recessed in the center. The first recess 56 surrounds the side surface of the crank chamber 52 where the boss portion 46 of the movable scroll 40 is arranged.

[0065] (2-4) Motor The motor 70 is a mechanism that drives the compression mechanism 20.

[0066] The motor 70 mainly includes a stator 72 and a rotor 74. The stator 72 is an annular member fixed to the inner peripheral surface 12a of the cylindrical portion 12 of the casing 10. The rotor 74 is a cylindrical member arranged inside the annular stator 72.

[0067] The rotor 74 is connected to the movable scroll 40 of the compression mechanism 20 via a drive shaft 80. Specifically, the rotor 74 is connected to the boss portion 46 of the movable scroll 40 via the drive shaft 80 (see FIG. 2). The motor 70 rotates the rotor 74 by a rotating magnetic field generated by the stator 72 to turn the movable scroll 40.

[0068] (2-5) Drive Shaft The drive shaft 80 transmits the driving force of the motor 70 to the compression mechanism 20. Specifically, the drive shaft 80 connects the rotor 74 of the motor 70 and the movable scroll 40 of the compression mechanism 20, and transmits the driving force of the motor 70 to the movable scroll 40 of the compression mechanism 20.

[0069] The drive shaft 80 extends in the vertical direction. The drive shaft 80 extends vertically from the lower part of the internal space S of the casing 10 to the crank chamber 52.

[0070] As shown in FIG. 2, the drive shaft 80 mainly has a main shaft 82 connected to the rotor 74 of the motor 70 and an eccentric portion 84 that is eccentric with respect to the central axis of the main shaft 82. The main shaft 82 is rotatably supported by a rolling bearing 112 and a bearing metal 91 arranged in a lower bearing housing 90 described later.

[0071] Inside the drive shaft 80, an oil passage 86 is formed. The oil passage 86 has a main passage 86a and a branch passage (not shown). The main passage 86a extends axially through the drive shaft 80 from the lower end to the upper end of the drive shaft 80. The branch passage extends from the main passage 86a in a direction intersecting the axial direction of the drive shaft 80. The oil flowing through the main passage 86a and flowing out from the upper end of the drive shaft 80, and the oil flowing from the main passage 86a into the branch passage and flowing out from the branch passage are supplied to, for example, the sliding portion between the bearing metal 47 and the eccentric portion 84, the sliding portion between the rolling bearing 112 and the bearing metal 91 and the main shaft 82, and the sliding portion of the compression mechanism 20. The oil supplied to the sliding portion is recovered into the oil reservoir space 16 through a path not shown.

[0072] A pumping mechanism 87 is provided at the lower end of the main shaft 82 of the drive shaft 80. The pumping mechanism 87 pumps oil from the oil reservoir space 16 at the lower part of the internal space S of the casing 10 by a positive displacement pump action. The pumping mechanism 87 takes in the oil in the oil reservoir space 16 from the intake port 88a of the suction nozzle 88. The oil taken in from the intake port 88a is supplied to one end (lower end) of the main passage 86a of the oil passage 86 and flows to the other end (upper end) of the main passage 86a.

[0073] The pumping mechanism 87 is covered by a filter 89. The filter 89 covers at least the intake port 88a of the suction nozzle 88. The filter 89 is, for example, a mesh-like member. The filter 89 suppresses solid foreign matters mixed in the oil existing in the oil reservoir space 16, such as solid decomposition products of the oil and wear powder generated at the sliding portion of the compressor, from being taken in from the intake port 88a together with the oil.

[0074] (2-6) Lower bearing housing The lower bearing housing 90 (see FIG. 2) is disposed below the motor 70.

[0075] The lower bearing housing 90 mainly includes a main body portion 92 provided therein with a bearing metal 91 for rotatably supporting a drive shaft 80, and an arm 94 extending in the radial direction of the cylindrical portion 12 of the casing 10 from the main body portion 92. The end of the arm 94 is attached to the inner peripheral surface 12a of the cylindrical portion 12 of the casing 10.

[0076] (2-7) Oil recovery section The oil recovery section 210 is a mechanism for recovering oil in the internal space S of the casing 10 from the lower part of the internal space S of the casing 10. The oil recovery section 210 includes a first pipe 212 and a first valve 214.

[0077] The first pipe 212 is a member that is disposed to penetrate the casing 10 and forms an oil flow path. The oil in the oil sump space 16 at the lower part of the internal space S of the casing 10 is recovered through the first pipe 212. The first pipe 212 may be a single member or may include a plurality of members that form an oil flow path. In the present embodiment, the first pipe 212 is disposed to penetrate the lower lid 14b of the casing 10, but is not limited thereto, and may be disposed to penetrate the cylindrical portion 12 of the casing 10.

[0078] One end (first end 212a) of the first pipe 212 is disposed inside the oil sump space 16 in the casing 10 as shown in FIG. 2. A suction port 213 for taking in the oil in the oil sump space 16 is provided at the first end 212a of the first pipe 212 (see FIG. 2). The other end (second end 212b) of the first pipe 212 is connected to the first valve 214 as shown in FIG. 2. Although not limiting the shape, the first pipe 212 includes a first portion 212c and a second portion 212d. The first portion 212c extends obliquely upward from the first end 212a. The second portion 212d is connected to the first portion 212c and extends horizontally from the first portion 212c to the second end 212b. However, the shape of the first pipe 212 is not limited to the shape depicted in FIG. 2, and may be an L-shaped or straight pipe shape.

[0079] When recovering oil, the first end 212a of the first pipe 212 is preferably disposed near the bottom surface of the casing 10 (near the bottom surface 14ba of the lower lid 14b) so that foreign matter deposited on the bottom surface of the casing 10 together with the oil can be easily recovered. Also, when recovering oil, the oil suction port 213 of the first pipe 212 preferably faces the bottom surface of the casing 10 (the bottom surface 14ba of the lower lid 14b). In other words, the oil suction port 213 of the first pipe 212 preferably faces the bottom surface 14ba of the lower lid 14b. More preferably, the oil suction port 213 of the first pipe 212 is the bottom surface 14ba of the lower lid 14b and is directed directly below or in the vicinity directly below the filter 89.

[0080] The first valve 214 is closed except when recovering oil so that the oil and refrigerant inside the scroll compressor 100 do not flow out through the first pipe 212 to the outside of the scroll compressor 100. When recovering oil, a tube (not shown) for connecting between an oil recovery container (not shown) and the first valve 214 is connected to the first valve 214. When the first valve 214 is opened with the tube connected, the oil inside the scroll compressor 100 passes through the tube and is recovered into the oil recovery container. The method of oil exchange (recovery and filling method) will be described later.

[0081] (2-8) Oil filling section The oil filling section 220 is a mechanism for filling the internal space S of the casing 10 with oil. The oil filling section 220 includes a second pipe 222 and a second valve 224.

[0082] The second pipe 222 is a member that forms a flow path for oil and is disposed to penetrate the casing 10. The internal space S of the casing 10 is filled with oil through the second pipe 222. The second pipe 222 may be a single member or may include a plurality of members that form a flow path for oil. In the present embodiment, the second pipe 222 is disposed to penetrate the lower lid 14b of the casing 10, but is not limited thereto, and may be disposed to penetrate the cylindrical portion 12 of the casing 10.

[0083] One end (the first end 222a) of the second pipe 222 is disposed inside the oil sump space 16 within the casing 10 as shown in FIG. 2. A discharge port 223 for supplying oil to the casing 10 is provided at the first end 222a of the second pipe 222. The other end (the second end 222b) of the second pipe 222 is connected to the second valve 224. Although not limiting the shape, the second pipe 222 includes a first portion 226 and a second portion 222d. The first portion 226 extends obliquely upward from the first end 222a. In other words, the first portion 226 extends downward toward the discharge port 223. Specifically, the first portion 226 extends obliquely downward toward the discharge port 223. The second portion 222d is connected to the first portion 226 and extends horizontally from the first portion 226 to the second end 222b.

[0084] The position of the discharge port 223 of the second pipe 222 and the direction in which the discharge port 223 is directed are preferably determined so as to facilitate the movement of foreign matter deposited in the oil sump space 16 during oil filling.

[0085] Also, the discharge port 223 of the second pipe 222 is preferably arranged and configured such that foreign matter attached to the filter 89 is easily removed from the filter 89. For example, the discharge port 223 of the second pipe 222 preferably faces the filter 89. In other words, the oil discharge port 223 of the second pipe 222 preferably faces the filter 89. As another example, the position of the discharge port 223 of the second pipe 222 and the direction in which the first portion 226 in which the discharge port 223 is formed extends may be designed such that the discharge port 223 faces the bottom surface 14ba of the lower lid 14b, and the oil discharged from the discharge port 223 hits the bottom surface 14ba and changes direction so that the filter 89 is wetted with oil. By designing the position of the discharge port 223 and the direction in which the first portion 226 extends in this way, the removal of foreign matter attached to the filter 89 is facilitated by the flow of oil when filling the oil from the second pipe 222.

[0086] The second valve 224 is closed so that the oil and refrigerant inside the scroll compressor 100 do not flow out of the scroll compressor 100 through the second pipe 222 except during oil filling. During oil filling, a tube (not shown) for connecting between an oil container that houses oil (not shown) and the second valve 224 is connected to the second valve 224. When the second valve 224 is opened with the tube connected, the oil in the oil container is filled into the scroll compressor 100 through the tube. The method of oil exchange (recovery and filling method) will be described later.

[0087] (3) Operation of Scroll Compressor The operation of the scroll compressor 100 will be described. Here, the operation of the scroll compressor 100 in a steady state (a state where the operation has started and stabilized) will be described.

[0088] When the motor 70 is driven, the rotor 74 rotates due to the rotating magnetic field generated by the stator 72, and the drive shaft 80 connected to the rotor 74 also rotates. When the drive shaft 80 rotates, due to the function of the Oldham coupling 24, the movable scroll 40 revolves around the fixed scroll 30 without rotating itself. Then, the low-pressure refrigerant in the refrigeration cycle of the refrigeration device flowing in from the suction pipe 18a is sucked into the compression chamber Sc on the peripheral side of the compression mechanism 20 through the suction hole 36a. As the movable scroll 40 revolves and the volume of the compression chamber Sc decreases, the pressure in the compression chamber Sc rises. As the refrigerant moves from the peripheral side (outer side) compression chamber Sc to the central side (inner side) compression chamber Sc, the pressure of the refrigerant rises and finally becomes the high pressure in the refrigeration cycle of the refrigeration device. The refrigerant compressed by the compression mechanism 20 is discharged from the discharge port 33 located near the center of the first mirror plate 32, passes through the refrigerant path (not shown) formed in the fixed scroll 30 and the housing 50, and flows into the space between the housing 50 and the motor 70. Also, the refrigerant compressed by the compression mechanism 20 and passing through the refrigerant path (not shown) formed in the fixed scroll 30 and the housing 50 also flows into the oil sump space 16 through the gap between the stator 72 and the cylindrical portion 12 and the like. The refrigerant gas flowing into the oil sump space 16 flows into the space between the housing 50 and the motor 70 through the gap between the stator 72 and the rotor 74 and the gap between the stator 72 and the cylindrical portion 12. The high-pressure refrigerant in the refrigeration cycle flowing into the space between the housing 50 and the motor 70 is finally discharged from the discharge pipe 18b.

[0089] (4) Oil replacement process The method of replacing the oil in the scroll compressor 100 will be described with reference to the flowchart of FIG. 3. FIG. 3 is an example of a flowchart of the method for replacing the oil in the compressor of the present disclosure. As a premise for the description, at the start point of oil replacement, the first valve 214 and the second valve 224 are closed.

[0090] In the method described below, all operations (for example, the opening and closing operations of valves, and the start-up and stop operations of various devices) may be performed manually. Alternatively, some or all of the operations may be automatically executed by a control unit including a computer. When the valve is automatically controlled, an electric valve, a solenoid valve, a valve driven by pneumatic pressure, or the like is used for the valve.

[0091] Although not limited thereto, before recovering oil from the internal space S of the casing 10 of the scroll compressor 100, for example, recovery of the refrigerant in the internal space S of the casing 10 and evacuation of the internal space S of the casing 10 are performed.

[0092] In the oil exchange, first, the internal space S of the casing 10 of the scroll compressor 100 is filled with gas, and the pressure of the internal space S is increased (step S1). Specifically, a gas cylinder filled with gas (not shown) is connected to the sampling port of the shut-off valve 6 of the refrigeration cycle apparatus 1 via a tube (not shown). The gas filled in the internal space S of the casing 10 is, for example, nitrogen, which is an inert gas. Nitrogen is filled until the pressure of the internal space S of the casing 10 reaches a predetermined pressure. The predetermined pressure is a pressure higher than atmospheric pressure. Thereafter, the connection between the gas cylinder and the sampling port of the shut-off valve 6 is released. Here, the release of the connection is not limited to removing the tube connecting the gas cylinder and the sampling port of the shut-off valve 6 from the sampling port of the shut-off valve 6, and includes cases where the gas cylinder and the sampling port of the shut-off valve 6 are made non-communicating using a valve or the like.

[0093] Next, oil is recovered from the lower part of the internal space S of the casing 10 of the scroll compressor 100 through the first pipe 212 of the oil recovery unit 210 (step S2). Specifically, an oil recovery container (not shown) is connected to the first valve 214 of the oil recovery unit 210 via a tube (not shown). Then, with the oil recovery container connected to the first valve 214, the first valve 214 is opened. As a result, due to the pressure difference between the internal space S of the casing 10 filled with gas and the outside of the casing 10, oil is recovered from the lower part of the internal space S of the casing 10 into the oil recovery container through the first pipe 212. At this time, together with the oil, foreign substances mixed in the oil are also recovered into the oil recovery container. Note that a filter (not shown) may be disposed in the tube connecting the first pipe 212 and the oil recovery container to remove foreign substances with the filter. After the oil is recovered, the first valve 214 is closed.

[0094] Next, the internal space S of the casing 10 of the scroll compressor 100 is evacuated (step S3). Specifically, a vacuum pump (not shown) is connected to the sampling ports of the shut-off valves 5 and 6 of the refrigeration cycle device 1 via a tube (not shown). When the vacuum pump is operated, at least a part of the refrigerant circuit 7 of the refrigeration cycle device 1 including the internal space S of the casing 10 of the scroll compressor 100 becomes a vacuum state. When the evacuation of the internal space S of the casing 10 is completed, the connection between the shut-off valves 5 and 6 and the vacuum pump is released. Note that the release of the connection here is not limited to removing the tube connecting the sampling ports of the shut-off valves 5 and 6 and the vacuum pump from the sampling ports of the shut-off valves 5 and 6, and includes cases where the vacuum pump and the sampling ports of the shut-off valves 5 and 6 are made non-communicating using valves or the like.

[0095] Next, the internal space S of the casing 10 of the scroll compressor 100 is filled with oil through the second pipe 222 of the oil filling section 220 (step S4). Specifically, a tube (not shown) for connecting between an oil container storing oil (not shown) and the second valve 224 is connected to the second valve 224 of the oil filling section 220. Then, with the tube connected, the second valve 224 is opened. As a result, due to the pressure difference between the internal space S of the casing 10 filled with gas and the outside of the casing 10, oil flows into the internal space S of the casing 10 through the second pipe 222.

[0096] When oil flows into the casing 10 through the second valve 224, the movement of foreign matter deposited on the bottom surface 14ba etc. of the casing 10 is promoted. Also, when the discharge port 223 of the second pipe 222 faces the filter 89, the oil directly hits the filter 89. As a result, at least a part of the foreign matter adhering to the filter 89 is removed from the filter 89 by the oil discharged from the discharge port 223 of the second pipe 222. In step S4, the internal space S of the casing 10 is filled with a predetermined amount of oil. After the predetermined amount of oil is filled, the second valve 224 is closed.

[0097] Thereafter, in steps S5 to S8, the same processes as steps S1 to S4 are executed. In short, in the oil exchange method of the present embodiment, the series of processes of steps S1 to S4 are repeatedly executed.

[0098] After step S8 ends, for example, evacuation of the internal space S of the casing 10 and filling of the internal space S of the casing 10 with refrigerant are performed.

[0099] Although not shown in the flowchart of FIG. 3, before restarting the operation of the refrigeration cycle device 1, unnecessary tubes connected to the sampling ports of the shut-off valves 5 and 6, the first valve 214 of the oil recovery section 210, and the second valve 224 of the oil filling section 220 are removed.

[0100] (5) Features (5-1) The scroll compressor 100 of the present embodiment includes a compression mechanism 20, a casing 10, a first pipe 212, and a second pipe 222 different from the first pipe 212. The casing 10 houses the compression mechanism 20. The first pipe 212 is disposed to penetrate the casing 10 and recover oil from the lower part of the internal space S of the casing 10. The second pipe 222 is disposed to penetrate the casing 10 and fill the internal space S of the casing 10 with oil.

[0101] In the scroll compressor 100 of the present embodiment, by using the first pipe 212 and the second pipe 222 as separate pipes, a structure suitable for oil recovery can be adopted for the first pipe 212, and a structure suitable for oil filling and foreign matter removal can be adopted for the second pipe 222. Therefore, compared with the case of using a single pipe for oil recovery and filling, the removal rate of foreign matter existing in the space where the oil is accumulated at the lower part of the casing 10 can be increased.

[0102] (5-2) The scroll compressor 100 of the present embodiment includes a pumping mechanism 87 and a filter 89. The pumping mechanism 87 pumps oil from the oil sump space 16 at the lower part of the internal space S of the casing 10. The filter 89 covers the oil intake port 88a of the pumping mechanism 87 from the oil sump space 16 at the lower part of the internal space S of the casing 10. By filling oil from the second pipe 222, foreign matter attached to the filter 89 is removed.

[0103] In the scroll compressor 100 of the present embodiment, foreign matter attached to the filter 89, which is difficult to remove when a single pipe is used for oil recovery and filling, can be removed when filling oil from the second pipe 222.

[0104] (5-3) In the scroll compressor 100 of the present embodiment, the oil discharge port 223 of the second pipe 222 faces the filter 89.

[0105] In the scroll compressor 100 of the present embodiment, since the oil discharge port 223 of the second pipe 222 is directed toward the filter 89, it is easy to remove foreign matter attached to the filter with the oil discharged from the second pipe 222.

[0106] (5-4) In the scroll compressor 100 of the present embodiment, the second pipe 222 includes a first portion 226. The first portion 226 extends downward toward the discharge port 223.

[0107] In the scroll compressor 100 of the present embodiment, since the second pipe 222 includes the first portion 226, it is easy to remove foreign matter adhering to the filter 89 with the oil discharged from the second pipe 222.

[0108] (5-5) In the scroll compressor 100 of the present embodiment, the end portion (the first end 212a) where the oil suction port 213 of the first pipe 212 is provided is disposed near the bottom surface 14ba of the casing 10 (the bottom surface 14ba of the lower lid 14b of the casing 10).

[0109] In the present disclosure, since a second pipe 222 different from the first pipe 212 is used for oil filling, a structure and arrangement particularly suitable for oil recovery can be adopted for the structure and arrangement of the first pipe 212. In the scroll compressor 100 of the present embodiment, since the suction port 213 of the first pipe 212 is disposed near the bottom surface 14ba of the casing 10, it is easy to remove foreign matter deposited on the bottom surface 14ba of the casing 10 during oil recovery.

[0110] (5-6) In the scroll compressor 100 of the present embodiment, the oil suction port 213 of the first pipe 212 faces the bottom surface 14ba of the casing 10.

[0111] In the scroll compressor 100 of the present embodiment, since the suction port 213 of the first pipe 212 is directed toward the bottom surface 14ba of the casing 10, it is easy to remove foreign matter accumulated on the bottom surface 14ba of the casing 10 during oil recovery.

[0112] (5-7) The method for exchanging oil in the compressor of the present embodiment (scroll compressor 100 in the present embodiment) includes a first step, a second step, a third step, and a fourth step. In the first step (steps S1, S5), the internal space S of the casing 10 is filled with gas (nitrogen in the present embodiment), and the internal pressure is increased. In the second step (steps S2, S6), due to the pressure difference between the internal space S of the casing 10 and the outside of the casing 10, oil is recovered from the lower part of the internal space S of the casing 10 through the first pipe 212. In the third step (steps S3, S7), the internal space S of the casing 10 is evacuated. In the fourth step (steps S4, S8), the internal space S of the casing 10 is filled with oil through the second pipe 222.

[0113] In the method for exchanging oil of the present embodiment, compared with the case of using a single pipe for oil recovery and filling, the removal rate of foreign matters existing in the space where the oil is accumulated in the lower part of the internal space of the casing 10 can be increased.

[0114] (5-8) In the method for exchanging oil in the compressor of the present embodiment, the above first step to fourth step are repeatedly executed.

[0115] In the method for exchanging oil in the compressor of the present embodiment, the removal rate of foreign matters existing in the space where the oil is accumulated in the lower part of the casing 10 can be particularly increased.

[0116] (6) Modification example The following shows a modification example of the above embodiment. Note that the following modification examples may be appropriately combined within a range that does not conflict with each other.

[0117] (6-1) Modification example A In the above embodiment, the compressor of the present disclosure is described by taking the scroll compressor 100 as an example. However, the type of the compressor of the present disclosure is not limited to the scroll compressor. The configuration of the present disclosure is widely applicable to compressors in which oil is stored in the lower part of the internal space of the casing. For example, the compressor of the present disclosure may be a rotary compressor.

[0118] (6-2) Variant B The shape of the second pipe 222 in the above embodiment is merely an example, and other shapes may be used.

[0119] For example, the second pipe 222 may have a shape as shown in FIG. 4. The second pipe 222 in FIG. 4 extends horizontally from the second end 222b, then once extends obliquely upward, and then changes its direction and extends obliquely downward toward the first end 222a where the discharge port 223 is formed. The discharge port 223 of the second pipe 222 is directed toward the filter 89. The second pipe 222 in FIG. 4 has a first portion 226a that extends at a steeper angle (extends in a direction closer to the vertical direction) than the first portion 226 of the second pipe 222 in FIG. 2 toward the discharge port 223. The first portion 226a extends in a direction generally along the side surface of the filter 89 that extends vertically. By having such a shape for the second pipe 222, it is possible to promote the removal of foreign matter adhering to the filter 89 with the oil discharged along the side surface of the filter 89 from the discharge port 223. The scroll compressor 100 of Variant B in FIG. 4 is the same as the scroll compressor 100 of the above embodiment except for the shape of the second pipe 222, so the description of other points is omitted.

[0120] Also, the second pipe 222 does not necessarily have a bent portion and may be a straight tubular member extending in the horizontal direction or an oblique direction.

[0121] (6-3) Variant C In the above embodiment, the second pipe 222 is used for oil filling, but it is not limited thereto and may be used for other purposes than oil filling. For example, the second pipe 222 may also be used as an oil equalizing pipe with other compressors. By also using the second pipe 222 as an oil equalizing pipe, the number of parts can be reduced compared to the case where an oil equalizing pipe is further provided separately from the first pipe 212 and the second pipe 222. A specific example will be described with reference to FIG. 5.

[0122] In the example of Fig. 5, the second pipe 222 of the scroll compressor 100A is used for filling oil into the scroll compressor 100A. Also, the second pipe 222 of the scroll compressor 100B is used for filling oil into the scroll compressor 100B. Further, the second pipes 222 of the scroll compressors 100A and 100B are also used as an oil equalizing pipe between the scroll compressor 100A and the scroll compressor 100B. Since the scroll compressors 100A and 100B have the same structure as the scroll compressor 100 of the above embodiment, the description thereof is omitted. In the example of Fig. 5, the second valve 224 of the oil filling portion 220 of the scroll compressor 100A and the second valve 224 of the oil filling portion 220 of the scroll compressor 100B are connected by a pipe 232. The pipe 232 extending between the two second valves 224 branches between the two second valves 224, and a valve 234 is provided at the branched portion of the pipe 232.

[0123] During the operation of the scroll compressor 100A and the scroll compressor 100B, both of the second valves 224 of the oil filling portions 220 of the scroll compressors 100A and 100B are open. The valve 234 is closed.

[0124] On the other hand, for example, when recovering and filling the oil of the scroll compressor 100A, the second valve 224 of the oil filling portion 220 of the scroll compressor 100A is opened, and the second valve 224 of the oil filling portion 220 of the scroll compressor 100B is closed. And when recovering and filling the oil of the scroll compressor 100A, the opening and closing of the valve 234 may be controlled in the same manner as the second valve 224 during the oil recovery and filling in the above embodiment.

[0125] (6-4) Modified Example D In the above embodiment, the flow passage area of the second pipe 222 is constant over the entire region from the first end 222a to the second end 222b. However, it is not limited thereto, and the flow passage area of the second pipe 222 may vary depending on the position.

[0126] For example, as shown in FIG. 6, the second pipe 1222 used in the scroll compressor 100 has a nozzle portion 228 whose flow passage area gradually decreases toward the discharge port 223. In the second pipe 1222, the nozzle portion 228 is provided in a first portion 226 that extends downward toward the discharge port 223. The nozzle portion 228 extends between a first end 228a and a second end 228b where the discharge port 223 is disposed. In the nozzle portion 228, the flow passage area for oil gradually decreases from the first end 228a toward the second end 228b. By having the nozzle portion 228 in the second pipe 1222, it is easy to increase the flow velocity of the oil discharged from the second pipe 1222 and remove foreign matter adhering to the filter 89 with the flow of the oil.

[0127] (6-5) Modification E In the above embodiment, a vertical scroll compressor in which the axial direction of the drive shaft 80 is the vertical direction has been described as an example. However, the compressor of the present disclosure may be a horizontal compressor in which the axial direction of the drive shaft 80 is the horizontal direction.

[0128] (6-6) Modification F In the oil exchange method of the above embodiment, it is assumed that the oil in the scroll compressor 100 is exchanged with new oil. However, the present invention is not limited to this, and the oil exchange here includes a case where the oil once taken out from the internal space S of the scroll compressor 100 is refilled after removing foreign matter.

[0129] (6-7) Modification G The oil exchange method described in the above embodiment is merely an example, and various modifications are possible.

[0130] For example, in the above embodiment, the first to fourth steps are repeatedly executed twice, but the first to fourth steps may be executed only once. Even in this case, foreign matter can be removed from the filter 89 etc. during oil filling, and the foreign matter removed from the filter 89 etc. together with the oil can be recovered during the next oil recovery.

[0131] Also, the first to fourth steps may be repeatedly executed three or more times.

[0132] Also, for example, the amount of oil filled in step S4 and the amount of oil filled in step S8 may be different.

[0133] Also, for example, steps S1 to S3 may be omitted, and oil filling in step S4 may be performed to stir the oil in the oil storage space 16 and remove foreign matters from the filter 89, and then the steps of steps S5 to S8 may be executed. By stirring the oil in the oil storage space 16, etc., the foreign matters deposited on the bottom surface 14ba of the casing 10 and the foreign matters attached to the filter 89 are moved, and it is easy to remove the foreign matters together with the oil in step S6.

[0134] Also, for example, in the above embodiment, the recovery and filling of oil are performed by utilizing the pressure difference inside and outside the casing 10, but it is not limited thereto. For example, a pump may be used for at least one of the recovery and filling of oil.

[0135] <Supplementary Note> As described above, the embodiments of the present disclosure have been described, but it will be understood that various changes in form and details are possible without departing from the spirit and scope of the present disclosure described in the claims.

Industrial Applicability

[0136] The present disclosure is widely applicable and useful for a compressor that stores oil in the internal space of a casing.

Explanation of Signs

[0137] 10 Casing 14ba Bottom surface 20 Compression mechanism 87 Pumping mechanism 88a Intake port 89 Filter 100 Scroll compressor (compressor) 212 First pipe 212a First end (end part) 213 Suction port 222, 1222 Second pipe 223 Discharge port 226 First part 228 Nozzle part 228a First end 228b Second end S Internal space

Prior art documents

Patent documents

[0138]

Patent Document 1

Claims

1. A compression mechanism (20), A casing (10) for housing the compression mechanism, A first pipe (212) disposed through the casing and recovering oil from the lower part of the internal space (S) of the casing, A second pipe (222, 1222) different from the first pipe, disposed through the casing and filling oil into the internal space of the casing, A pumping mechanism (87) for pumping oil from the lower part of the internal space of the casing, A filter (89) covering the oil intake port (88a) of the pumping mechanism from the lower part of the internal space of the casing, comprising By filling oil from the second pipe, foreign matter attached to the filter is removed, A compressor (100).

2. The oil discharge port (223) of the second pipe faces the filter, The compressor according to claim 1.

3. The second pipe includes a first portion (226) extending downward toward the discharge port, The compressor according to claim 2.

4. The second pipe (222) includes a nozzle portion (228) extending between a first end (228a) and a second end (228b) where the discharge port (223) is disposed, In the nozzle portion, the flow path area of the oil gradually decreases from the first end toward the second end, The compressor according to claim 2 or 3.

5. The end portion (212a) provided with the oil suction port (213) of the first pipe is disposed near the bottom surface (14ba) of the casing, The compressor according to any one of claims 1 to 4.

6. The oil suction port (213) of the first pipe faces the bottom surface (14ba) of the casing, The compressor according to any one of claims 1 to 5.

7. The second pipe functions as an oil equalizing pipe with another compressor. The compressor according to any one of claims 1 to 6.

8. An oil exchange method for a compressor (100) comprising a compression mechanism (20), a casing (10) for housing the compression mechanism, a first pipe (212) disposed through the casing and recovering oil from the lower part of the internal space (S) of the casing, and a second pipe (222, 1222) disposed through the casing and filling the internal space of the casing with oil, different from the first pipe, comprising: A first step (S2, S6) of filling the internal space of the casing with gas to increase the internal pressure; A second step (S3, S7) of recovering oil from the lower part of the internal space of the casing through the first pipe due to the pressure difference between the internal space of the casing and the outside of the casing; A third step (S4, S8) of evacuating the internal space of the casing; A fourth step (S5, S9) of filling the internal space of the casing with oil through the second pipe; An oil exchange method for a compressor, comprising the above steps.

9. A series of the first step to the fourth step is repeatedly executed. The oil exchange method for the compressor according to claim 8.

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