Compressor

Abstract

The present invention provides a compressor capable of reducing the likelihood of a lubricating oil containing a large amount of refrigerant being supplied to a sliding part. This compressor comprises: a compression mechanism (60) that compresses a refrigerant; a drive shaft (70) that extends in a vertical direction and drives the compression mechanism (60); a housing (10) which houses the compression mechanism (60) and the drive shaft (70) and at the bottom of which is formed a liquid reservoir (98) into which the refrigerant and the lubricating oil, that has a higher temperature and a lower density than the refrigerant, are guided; a pump unit (93) that is provided below the drive shaft (70) and that sucks up liquid stored in the liquid reservoir (98); a resistance member (95) provided at the bottom of the housing (10) and serving as resistance against the flow of the liquid stored in the liquid reservoir (98). The liquid refrigerant and the lubricating oil are guided to a first region of the liquid reservoir (98), the liquid is sucked up from a second region (R2) of the liquid reservoir (98) by the pump unit (93), and the resistance member (95) is installed between the first region and the second region (R2).

Description

Compressor

[0001] The present disclosure relates to a compressor.

[0002] For example, Patent Document 1 discloses a scroll compressor in which lubricating oil is sucked from an oil reservoir, the sucked lubricating oil is supplied to bearings, and the lubricating oil that has lubricated the bearings is returned to the oil reservoir via a partition plate.

[0003] Japanese Utility Model Application Laid-Open Publication No. 4-52585

[0004] The refrigerant drawn into the housing (shell in Patent Document 1) through the suction pipe is mainly guided to the compression mechanism. However, some of the refrigerant liquefies and flows along the inner circumferential surface of the housing to a liquid reservoir formed at the bottom of the housing. Some types of compressors are configured to return some of the liquid refrigerant to the housing through an injection pipe. The liquid refrigerant returned to the housing vaporizes and is mainly guided to the compression mechanism. However, some of the liquid refrigerant does not vaporize and flows along the inner circumferential surface of the housing to a liquid reservoir formed at the bottom of the housing.

[0005] In this way, at least the lubricating oil and liquid refrigerant are introduced into and stored in the liquid reservoir, but since the density of the lubricating oil is usually lower than that of the liquid refrigerant, the refrigerant will be located in the lower layer and the lubricating oil will be located in the upper layer in the liquid reservoir.

[0006] When the liquid that has separated into two layers is pumped up from the liquid reservoir, the liquid refrigerant in the lower layer may be directly pumped up by the pump. If this happens, the lubricating oil supplied to the sliding parts may contain a large amount of refrigerant, which may result in insufficient lubrication of the sliding parts and a loss of reliability of the sliding parts.

[0007] The present disclosure has been made in consideration of the above circumstances, and aims to provide a compressor that can reduce the possibility of lubricating oil containing a large amount of refrigerant being supplied to sliding parts.

[0008] In order to solve the above problems, the compressor of the present disclosure employs the following means: That is, a compressor according to one aspect of the present disclosure includes a compression mechanism that compresses a refrigerant, a drive shaft extending vertically and driving the compression mechanism, a housing that accommodates the compression mechanism and the drive shaft and has a liquid reservoir formed in its bottom, into which the refrigerant and a lubricating oil having a higher temperature and a lower density than the refrigerant are guided, a pump unit that is provided below the drive shaft and that pumps up the liquid stored in the liquid reservoir, and a resistance member that is provided at the bottom of the housing and provides resistance to the flow of the liquid stored in the liquid reservoir, wherein the liquid refrigerant and the lubricating oil are guided to a first region of the liquid reservoir, and the liquid is pumped up from a second region of the liquid reservoir by the pump unit, and the resistance member is located between the first region and the second region.

[0009] According to the present disclosure, it is possible to reduce the possibility that lubricating oil containing a large amount of refrigerant will be supplied to sliding parts.

[0010] Fig. 1 is a longitudinal sectional view of a scroll compressor according to an embodiment of the present disclosure; Fig. 2 is a transverse sectional view of a scroll compressor taken along the line II-II shown in Fig. 1 (Example 1); Fig. 3 is a transverse sectional view of a scroll compressor taken along the same cross-sectional position as Fig. 2 (Example 2); Fig. 4 is a transverse sectional view of a scroll compressor taken along the same cross-sectional position as Fig. 2 (Example 3, housing and the like omitted); Fig. 5 is a transverse sectional view of a scroll compressor taken along the same cross-sectional position as Fig. 2 (Example 3, housing and the like omitted).

[0011] Hereinafter, a compressor according to an embodiment of the present disclosure will be described with reference to the drawings.

[0012] [Configuration of the Scroll Compressor] The scroll compressor 1, as an example of a compressor, is one of the devices that make up a refrigeration cycle of, for example, an air conditioner, and is a device that compresses a refrigerant sealed in the refrigeration cycle. In addition to the scroll compressor 1, the refrigeration cycle includes devices such as a condenser, an expansion valve, and an evaporator, not shown, and piping that connects these devices. The refrigeration cycle may be, for example, an injection cycle configured to introduce liquid refrigerant into the scroll compressor 1.

[0013] As shown in FIG. 1, the scroll compressor 1 includes a housing 10 defining an enclosed space therein, a discharge cover 20 vertically dividing the enclosed space, a compression mechanism 60 that compresses the refrigerant, a drive shaft 70 that drives the compression mechanism 60, an electric motor 75 that rotates the drive shaft 70, a pump section 93 that sucks up a liquid containing lubricating oil, and a resistance member 95 that provides resistance to the flow of the liquid.

[0014] The housing 10 is, for example, a sealed container made of metal, and has a cylindrical intermediate housing 12 centered on an axis X extending vertically, an upper housing 11 that closes the upper end opening of the intermediate housing 12, and a lower housing 13 that closes the lower end opening of the intermediate housing 12.

[0015] The middle housing 12 and the upper housing 11 are connected with the outer peripheral end 21 of the discharge cover 20 sandwiched vertically therebetween. In this case, the outer peripheral end 21 of the discharge cover 20 can be considered to be part of the peripheral wall of the housing 10. The discharge cover 20 vertically divides the sealed space defined by the housing 10. Of the divided sealed spaces, the space above the discharge cover 20 is the discharge chamber C1, and the space below the discharge cover 20 is the suction chamber C2.

[0016] The intermediate housing 12 and the lower housing 13 are connected together with the inner peripheral surface of the lower housing 13 fitted onto the outer peripheral surface of the intermediate housing 12 .

[0017] A discharge pipe 31 is provided on the top surface of the upper housing 11, connecting the discharge chamber C1 with the outside of the upper housing 11 (housing 10), so that the refrigerant in the discharge chamber C1 is discharged to the outside of the upper housing 11. A refrigerant pipe (not shown) is connected to the end of the discharge pipe 31 (the end located outside the upper housing 11), so that the refrigerant discharged from the discharge pipe 31 is led to the condenser.

[0018] A refrigerant inlet 12a is provided on the peripheral wall of the intermediate housing 12, connecting the interior (sealed space) of the housing 10 with the outside, and an end of a suction pipe 32 is connected to the refrigerant inlet 12a. A refrigerant pipe is connected to the other end of the suction pipe 32, and gas refrigerant evaporated in the evaporator is introduced into the suction chamber C2 via the suction pipe 32.

[0019] A refrigerant introduction point 21a that connects the inside (sealed space) of the housing 10 to the outside is provided at the outer peripheral end 21 of the discharge cover 20, and an end of an injection pipe 33 is connected to the refrigerant introduction point 21a. A refrigerant pipe is connected to the other end of the injection pipe 33, and liquid refrigerant is introduced into the suction chamber C2 via the injection pipe 33. The liquid refrigerant is, for example, a condensed portion of the gas refrigerant compressed by the scroll compressor 1.

[0020] The suction chamber C2 is provided with devices and components such as a compression mechanism 60 for compressing the refrigerant, a drive shaft 70, an electric motor 75, a support member 80, and a resistance member 95.

[0021] The compression mechanism 60 has a fixed scroll 61 having a spiral-shaped fixed side wall body 63 standing on a fixed side end plate 62, and an orbiting scroll 65 having a spiral-shaped orbiting side wall body 67 standing on an orbiting side end plate 66. The fixed scroll 61 and the orbiting scroll 65 define a compression chamber C3 by the fixed side wall body 63 and the orbiting side wall body 67 meshing with each other.

[0022] The fixed scroll 61 is fixed to the support member 80 via a fixing portion 62a formed on the outer peripheral end of the fixed-side end plate 62. The support member 80 is fixed to the intermediate housing 12. As described above, the support member 80 is a member to which the fixed scroll 61 is fixed, a member that functions as a bearing that supports the drive shaft 70 in the radial direction, and a member that supports the orbiting scroll 65 in the direction of the axis X (details will be described later).

[0023] The discharge cover 20 is disposed above the fixed scroll 61. A cylindrical protrusion is formed in the center of the lower surface of the discharge cover 20 (the surface facing the fixed-side end plate 62), and this protrusion is fitted into an annular protrusion formed in the center of the back surface of the fixed-side end plate 62 (the surface facing the discharge cover 20). The cylindrical protrusion of the discharge cover 20 is fitted into the annular protrusion of the fixed-side end plate 62, thereby defining a back pressure chamber C4 between the discharge cover 20 and the fixed-side end plate 62.

[0024] A discharge port 62b that connects the compression chamber C3 and the back pressure chamber C4 is formed in the fixed end plate 62. A discharge port 22 that connects the back pressure chamber C4 and the discharge chamber C1 is formed in the discharge cover 20. In other words, the compression chamber C3 and the discharge chamber C1 are connected via the discharge port 62b, the back pressure chamber C4, and the discharge port 22.

[0025] A reed valve 52 and a retainer 53 that restricts the range of movement of the reed valve 52 are provided at the outlet of the discharge port 22. This ensures that the refrigerant is discharged from the discharge port 22 to the discharge chamber C1 only when the refrigerant reaches a predetermined pressure.

[0026] High-pressure refrigerant compressed by the compression mechanism 60 is introduced into the discharge chamber C1. Meanwhile, low-pressure refrigerant is introduced into the suction chamber C2 via the suction pipe 32. The low-pressure refrigerant introduced into the suction chamber C2 is drawn into the compression mechanism 60. Therefore, the scroll compressor 1 of this embodiment is configured such that the discharge cover 20 serves as a partition between the high-pressure space and the low-pressure space, and devices and parts such as the compression mechanism 60, drive shaft 70, and electric motor 75 are disposed in the low-pressure space. Note that the element separating the high-pressure space and the low-pressure space does not necessarily have to be the discharge cover 20; for example, the fixed scroll 61 may be used to separate the high-pressure space and the low-pressure space.

[0027] The orbiting scroll 65 is configured to revolve around the axis X relative to the fixed scroll 61 by means of a drive shaft 70 and a known rotation prevention mechanism.

[0028] The drive shaft 70 is a shaft member extending in the vertical direction for transmitting the driving force from the electric motor 75 to the orbiting scroll 65 to drive the compression mechanism 60. The drive shaft 70 has a main shaft portion 71 whose central axis is an axis X extending in the vertical direction, and a crankshaft portion 72 that is eccentric with respect to the axis X. An oil supply passage 70a extending in the vertical direction is formed inside the drive shaft 70. The lower end of the oil supply passage 70a is open and is configured to receive liquid from a pump portion 93 described later. The upper end of the oil supply passage 70a is also open and is configured to supply liquid to a drive bushing 85, a journal bearing 87, and their vicinity (hereinafter referred to as "sliding portions") described later.

[0029] A rotor 75a of an electric motor 75 is fitted onto the outer peripheral surface of the main shaft portion 71. Meanwhile, a stator 75b of the electric motor 75, which is paired with the rotor 75a, is fitted onto the inner peripheral surface of the intermediate housing 12. An upper portion of the main shaft portion 71 is inserted into a journal bearing portion 81 of a support member 80 and is journal-supported by the journal bearing portion 81 in the radial direction. A lower portion of the main shaft portion 71 is journal-supported in the radial direction and along the axis X by a lower bearing 91. That is, the lower bearing 91, which is located at the bottom of the housing 10, functions as a journal bearing and a thrust bearing for the main shaft portion 71.

[0030] A cylindrical drive bush 85 extending in the vertical direction is attached to the outer peripheral surface of the crankshaft 72. A counterweight 86 is attached to the outer peripheral surface of the drive bush 85.

[0031] A cylindrical bearing boss 66a with an open bottom end is formed in the center of the underside of the orbiting-side end plate 66. The crankshaft portion 72 of the drive shaft 70 is connected to the bearing boss 66a via a drive bushing 85 and a journal bearing 87.

[0032] An annular thrust plate 82 fixed to the support member 80 is in contact with the lower surface of the orbiting-side end plate 66. As a result, the orbiting scroll 65 is supported in a state in which it can slide relative to the support member 80 (thrust plate 82) in a direction perpendicular to the axis X.

[0033] A pump unit 93 is provided below and below the main shaft unit 71. The pump unit 93 is a mechanism that sucks up liquid from a liquid reservoir 98 formed in the bottom of the housing 10 (the bottom of the lower housing 13). The pump unit 93 is driven by the rotation of the main shaft unit 71. Here, the liquid includes lubricating oil and / or liquid refrigerant. The liquid may be, for example, only lubricating oil, only liquid refrigerant, or a mixture thereof.

[0034] The pump unit 93 has a nozzle 94, at least a lower portion of which is submerged in the liquid stored in a liquid reservoir 98. The pump unit 93 sucks up liquid from the liquid reservoir 98 through the nozzle 94 and supplies the sucked up liquid to the sliding part through the oil supply passage 70a of the drive shaft 70. The nozzle 94 has, for example, a cylindrical shape extending vertically. A suction port 94a is formed on the lower end surface of the nozzle 94, and liquid is sucked in through this suction port 94a. The suction port 94a of the nozzle 94 is preferably located near the bottom surface 13a of the lower housing 13 so that the pump unit 93 can reliably suck up the liquid (e.g., lubricating oil) even when the liquid level drops. However, if the suction port 94a of the nozzle 94 is located excessively close to the bottom surface 13a of the lower housing 13, foreign matter accumulated at the bottom of the lower housing 13 may be sucked up. Therefore, for example, it is preferable to separate the suction port 94a from the bottom surface 13a by a distance equal to or greater than the diameter of the suction port 94a.

[0035] An upper oil return point 12b and a lower oil return point 12c are provided on the peripheral wall of the intermediate housing 12, connecting the interior (sealed space) of the housing 10 with the outside. The upper oil return point 12b is located higher than the lower oil return point 12c. The upper oil return point 12b and the lower oil return point 12c are connected via an oil return pipe 34 located outside the intermediate housing 12. An oil return flow path 83 extending horizontally is formed in the support member 80. The oil return flow path 83 is a flow path that guides liquid discharged from the sliding parts (liquid that has lubricated the sliding parts) to the upper oil return point 12b of the intermediate housing 12. The liquid discharged from the sliding parts is configured to be guided back into the interior of the housing 10 (intermediate housing 12) via the oil return flow path 83 and the oil return pipe 34.

[0036] [Flow of refrigerant and lubricating oil in the scroll compressor] The gas refrigerant evaporated in the evaporator is guided to the suction chamber C2 via the suction pipe 32. The gas refrigerant guided to the suction chamber C2 is taken into the compression chamber C3 of the compression mechanism 60 and is gradually compressed as it moves from the outside of the compression chamber C3 toward the center. The compressed gas refrigerant is guided from the compression chamber C3 to the back pressure chamber C4 via the discharge port 62b formed in the fixed side end plate 62. The gas refrigerant guided to the back pressure chamber C4 is then guided from the back pressure chamber C4 to the discharge chamber C1 via the discharge port 22 formed in the discharge cover 20. The gas refrigerant guided to the discharge chamber C1 is then guided to the outside of the upper housing 11 (housing 10) via the discharge pipe 31.

[0037] The liquid refrigerant, which is a condensed portion of the gas refrigerant compressed by the scroll compressor 1, is introduced into the suction chamber C2 via the injection pipe 33. The liquid refrigerant introduced into the suction chamber C2 is vaporized (evaporated) and taken into the compression chamber C3 of the compression mechanism 60, where it is compressed together with the gas refrigerant introduced into the suction chamber C2 via the suction pipe 32.

[0038] As described above, the gas refrigerant introduced into the suction chamber C2 via the suction pipe 32 is mainly taken into the compression chamber C3, but a portion of the gas refrigerant liquefies and flows along the inner circumferential surface of the housing 10 (the middle housing 12 and the lower housing 13) and is introduced into the liquid reservoir 98 formed at the bottom of the housing 10 (the lower housing 13). Also, a portion of the liquid refrigerant introduced into the suction chamber C2 via the injection pipe 33 flows along the inner circumferential surface of the housing 10 and is introduced into the liquid reservoir 98 formed at the bottom of the housing 10 without vaporizing.

[0039] When the pump unit 93 is driven, the lubricating oil stored in a reservoir 98 formed at the bottom of the housing 10 is sucked up through the suction port 94a of the nozzle 94. The sucked up lubricating oil is supplied to the upper part of the sliding part through the oil supply passage 70a of the drive shaft 70, lubricating the sliding part. After lubricating the sliding part, the lubricating oil is discharged from the lower part of the sliding part. The temperature of the discharged lubricating oil is at least higher than the temperature of the refrigerant. The density of the lubricating oil is also lower than the density of the refrigerant. The lubricating oil discharged from the sliding part is guided back into the housing 10 (middle housing 12) via, for example, an oil return passage 83 formed in the support member 80 and an oil return pipe 34. At this time, the lower oil return point 12c connected to the lower end of the oil return pipe 34 is located, for example, near the lower part of the stator 75b of the electric motor 75. That is, the oil return pipe 34 defines a flow path for guiding the lubricating oil from the oil return flow path 83 to the inside of the housing 10 in a manner that bypasses most of the stator 75b of the electric motor 75. The lubricating oil that has been guided into the inside of the housing 10 flows along the inner circumferential surface of the housing 10 and is guided to a reservoir 98 formed at the bottom of the housing 10.

[0040] The oil return pipe 34 is not a required component, and the lubricating oil discharged from the sliding part may be guided, for example, through an oil return flow path 83 formed in the support member 80 to near the inner surface of the housing 10 (intermediate housing 12), and from there travel along the inner surface of the housing 10 to a liquid reservoir 98 formed at the bottom of the housing 10.

[0041] [Regarding the Resistance Member] As shown in FIG. 2 , the region (area) of the liquid reservoir 98 into which the liquid refrigerant and lubricating oil flowing down the inner circumferential surface of the housing 10 are guided is defined as a first region R1. Meanwhile, the region (area) of the liquid reservoir 98 into which the liquid is pumped by the pump unit 93 is defined as a second region R2. In this embodiment, the first region R1 is defined as a region (area) near the refrigerant introduction point 12a, the refrigerant introduction point 21a, and the lower oil return point 12c when viewed from the direction of the axis X. Furthermore, because the refrigerant introduction point 12a, the refrigerant introduction point 21a, and the lower oil return point 12c are provided on the circumferential wall of the housing 10, the first region R1 necessarily extends along the inner circumferential surface of the housing 10. Meanwhile, the second region R2 is defined as a region (area) near the nozzle 94 (suction port 94a). The first region R1 and the second region R2 are three-dimensional regions having a depth corresponding to the liquid surface level of the liquid stored in the liquid reservoir 98.

[0042] The liquid refrigerant and lubricating oil are introduced into the liquid reservoir 98, but because the density of the lubricating oil is lower than that of the refrigerant, the refrigerant is located in the lower layer and the lubricating oil is located in the upper layer in the liquid reservoir 98. That is, in the liquid reservoir 98, the liquid containing the lubricating oil and the refrigerant is separated into two layers, upper and lower.

[0043] As described above, since the suction port 94a is located near the bottom surface 13a of the lower housing 13, if no measures are taken, the liquid refrigerant in the lower layer may be directly sucked up by the pump unit 93. If this happens, the lubricating oil supplied to the sliding parts will contain a large amount of refrigerant, which may result in insufficient lubrication of the sliding parts and a loss of reliability of the sliding parts.

[0044] 1 and 2, at least one resistance member 95 is provided between the first region R1 and the second region R2. The resistance member 95 is a member that provides resistance to the flow of the liquid stored in the liquid reservoir 98, and is provided at the bottom of the housing 10 (the bottom of the lower housing 13).

[0045] The installation of the resistance member 95 provides the following effects. Specifically, it is less likely that the liquid refrigerant in the lower layer in the first region R1 will flow into the second region R2. This reduces the possibility that the pump unit 93 will pump up a large amount of lubricating oil containing the refrigerant, supplying the liquid to the sliding parts and causing problems in the sliding parts. Furthermore, the time it takes for the liquid refrigerant guided to the first region R1 to reach the second region R2 is longer than when the resistance member 95 is not provided. This increases the time that the liquid refrigerant in the lower layer comes into contact with the high-temperature lubricating oil in the upper layer. This ensures time for the liquid refrigerant to vaporize, reducing the amount of liquid refrigerant flowing into the second region R2. This reduces the possibility that the pump unit 93 will pump up a large amount of lubricating oil containing the refrigerant, supplying the liquid to the sliding parts and causing problems in the sliding parts. Furthermore, the time it takes for the liquid refrigerant guided to the first region R1 to reach the second region R2 is longer than when the resistance member 95 is not provided. This allows the liquid refrigerant in the lower layer to be in contact with the high-temperature lubricating oil in the upper layer for a longer period of time, allowing the liquid refrigerant to dissolve appropriately in the lubricating oil, cooling the lubricating oil and appropriately reducing the viscosity of the lubricating oil, thereby reducing friction loss at the sliding parts to which the liquid is supplied.

[0046] In this case, it is preferable that the lower end of the resistance member 95 is connected to the bottom surface 13a of the lower housing 13 without any gap. This makes it difficult for the liquid refrigerant in the lower layer in the first region R1 to flow into the second region R2. However, a gap may be formed between the lower end of the resistance member 95 and the bottom surface 13a of the lower housing 13. This is because the presence of the resistance member 95 at least blocks the flow of liquid refrigerant from the first region R1 to the second region R2, compared to when the resistance member 95 is not present. From a processing standpoint, it is not easy to form the lower end of the resistance member 95 to fit the curved shape of the bottom surface 13a of the lower housing 13. Therefore, the shape of the lower end of the resistance member 95 may be made easier to process, such as a linear shape.

[0047] The upper end 96 of the resistance member 95 is preferably located above the lower end surface of the nozzle 94 of the pump section 93. This makes it difficult for the liquid refrigerant in the lower layer in the first region R1 to be directly sucked into the suction port 94a of the nozzle 94. Furthermore, the upper end 96 of the resistance member 95 is preferably located below the liquid level during normal operation. That is, at the liquid level during normal operation, the resistance member 95 is preferably submerged in the liquid stored in the liquid reservoir 98. This makes it easier for the lubricating oil in the upper layer in the first region R1 to flow into the second region R2.

[0048] The material of the resistance member 95 is not particularly limited, and may be, for example, metal or resin. If the resistance member 95 is metal, the resistance member 95 can be fixed to the lower housing 13 by welding. If the resistance member 95 is resin, even if the resistance member 95 comes off and comes into contact with the electric motor 75 while it is running, the electric motor 75 is less likely to be damaged.

[0049] The resistance member 95 will be described below using several examples.

[0050] 1 and 2 , the resistance member 95 is a cylindrical member having a circular cross-sectional shape (cross-sectional shape in a plane perpendicular to the axis X). The cylindrical resistance member 95 surrounds the entire periphery of the nozzle 94. However, when viewed from the direction of the axis X, the resistance member 95 and the nozzle 94 are spaced apart and do not contact each other. This makes it more difficult for the liquid refrigerant in the lower layer in the first region R1 to flow into the second region R2 than when the resistance member 95 is provided only in a partial area around the nozzle 94. Furthermore, the time it takes for the liquid refrigerant guided to the first region R1 to reach the second region R2 is longer than when the resistance member 95 is provided only in a partial area around the nozzle 94.

[0051] 2, the resistance member 95 stands upright from the bottom surface 13a of the lower housing 13. That is, the lower end of the resistance member 95 is connected without any gap to the bottom surface 13a of the lower housing 13. However, as described above, a gap may be provided between the lower end of the resistance member 95 and the bottom surface 13a of the lower housing 13.

[0052] 2, the center of the resistance member 95 coincides with the axis X. However, the center of the resistance member 95 does not need to coincide with the axis X, and may coincide with the center of the nozzle 94, for example. In either case, it is sufficient that the resistance member 95 separates the first region R1 and the second region R2 and surrounds the entire periphery of the nozzle 94. Furthermore, the cross-sectional shape of the resistance member 95 may be other than circular, and may be, for example, elliptical or polygonal.

[0053] The resistance member 95 preferably has holes 97 formed therein that connect the inside and outside of the resistance member 95. This allows at least the liquid containing the lubricating oil to be guided from the first region R1 to the second region R2, even if the liquid level temporarily drops below the upper end of the resistance member 95. Therefore, even if the liquid level temporarily drops below the upper end of the resistance member 95, the lubrication of the sliding parts is at least maintained.

[0054] The hole 97 is preferably formed in the vertical direction in a range from the lower end surface of the nozzle 94 to the bottom surface 13 a of the lower housing 13 .

[0055] The diameter of the hole 97 is preferably equal to or larger than the diameter of the suction port 94a. If the diameter of the hole 97 were smaller than the diameter of the suction port 94a, the amount of liquid guided to the second region R2 through the hole 97 would be less than the amount of liquid sucked from the suction port 94a, which could result in a shortage of liquid (lubricant) in the second region R2.

[0056] Example 2 As shown in FIG. 3 , the resistance member 95 is a plate-like member with an outwardly convex arc cross section. The resistance member 95 surrounds only a portion of the nozzle 94. However, when viewed from the direction of the axis X, the resistance member 95 and the nozzle 94 are separated and do not contact each other. Here, the "partial area" refers to a region between a region of the first region R1 where a relatively large amount of refrigerant is present and the second region R2. For example, when viewed from the direction of the axis X, the region is between the refrigerant introduction point 21a connected to the injection pipe 33 and the suction port 94a of the nozzle 94, and / or the region is between the refrigerant introduction point 12a connected to the suction pipe 32 and the suction port 94a of the nozzle 94. This allows the resistance member 95 to be provided only in the path from the first region R1 to the second region R2 where a relatively large amount of refrigerant flows. Therefore, even if the resistance member 95 is not provided over the entire area around the nozzle 94, the time it takes for the liquid refrigerant introduced into the first region R1 to reach the second region R2 can be lengthened.

[0057] The cross-sectional shape of the resistance member 95 may be other than an arc shape, for example, a straight line shape.

[0058] Example 3 As shown in FIG. 4 , the resistance member 95 has a spiral cross-sectional shape centered on the nozzle 94. However, when viewed from the direction of the axis X, the resistance member 95 and the nozzle 94 are spaced apart and do not contact each other. By forming the resistance member 95 in a spiral cross-sectional shape, a spiral path is defined from the first region R1 to the second region R2. The spiral path has a longer distance (the distance can be efficiently extended) than, for example, a linear path from the first region R1 to the second region R2. This increases the time it takes for the liquid refrigerant introduced into the first region R1 to reach the second region R2.

[0059] Furthermore, as shown in Figure 5, the same effect can be achieved by making each resistance member 95 a plate material with a cross-sectional shape that is an outwardly convex arc, and arranging two resistance members 95 so that they sandwich the nozzle 94 and are offset from each other (alternate).

[0060] Fourth Embodiment The resistance member 95 described above may be a mesh member. By using a mesh resistance member 95, the liquid refrigerant is more likely to dissolve into the lubricating oil as it passes through the resistance member 95 (mesh). This cools the lubricating oil and appropriately reduces the viscosity of the lubricating oil, thereby reducing friction loss at the sliding parts to which the liquid is supplied.

[0061] [Additional Notes] The compressor according to the embodiment of the present disclosure described above can be understood, for example, as follows.

[0062] A scroll compressor (1) according to a first aspect of the present disclosure includes a compression mechanism (60) that compresses a refrigerant, a drive shaft (70) that extends vertically and drives the compression mechanism, a housing (10) that accommodates the compression mechanism and the drive shaft and has a liquid reservoir (98) formed at its bottom into which the refrigerant and lubricating oil, which has a higher temperature and a lower density than the refrigerant, are guided, a pump section (93) that is provided below the drive shaft and that draws up the liquid stored in the liquid reservoir, and a resistance member (95) that is provided at the bottom of the housing and provides resistance to the flow of the liquid stored in the liquid reservoir, wherein the liquid refrigerant and lubricating oil are guided to a first region (R1) of the liquid reservoir, and the liquid is drawn up from a second region (R2) of the liquid reservoir by the pump section, and the resistance member is installed between the first region and the second region.

[0063] The housing includes a resistance member disposed at the bottom thereof, which provides resistance to the flow of the liquid stored in the liquid reservoir. The liquid refrigerant and lubricating oil are guided to a first region of the liquid reservoir, and the liquid is pumped up from a second region of the liquid reservoir. The resistance member is disposed between the first and second regions, making it difficult for the liquid refrigerant in the lower layer of the first region to flow into the second region. This reduces the possibility of a phenomenon in which a large amount of lubricating oil containing refrigerant is pumped up by the pump unit and supplied to the sliding parts, causing malfunctions in the sliding parts. Furthermore, the time it takes for the liquid refrigerant guided to the first region to reach the second region is longer than in a case in which the resistance member is not provided. This increases the time the liquid refrigerant in the lower layer comes into contact with the high-temperature lubricating oil in the upper layer. This ensures time for the liquid refrigerant to evaporate, reducing the amount of liquid refrigerant flowing into the second region. This reduces the possibility of a phenomenon in which a large amount of lubricating oil containing refrigerant is pumped up by the pump unit and supplied to the sliding parts, causing malfunctions in the sliding parts. Furthermore, the time it takes for the liquid refrigerant introduced into the first region to reach the second region is longer than when the resistance member is not provided. This increases the time that the liquid refrigerant in the lower layer comes into contact with the high-temperature lubricating oil in the upper layer. This allows the liquid refrigerant to dissolve appropriately in the lubricating oil, cooling the lubricating oil and appropriately reducing the viscosity of the lubricating oil, thereby reducing friction loss at the sliding parts to which the liquid is supplied.

[0064] In the compressor according to the second aspect of the present disclosure, in the first aspect, the pump section has a nozzle (94) whose lower part is submerged in the liquid reservoir, and the resistance member is provided in at least a portion of the area around the nozzle.

[0065] Since the resistance member is provided in at least a portion of the periphery of the nozzle, the liquid refrigerant in the lower layer in the first region is less likely to flow into the second region than in a case where the resistance member is not provided, and the time it takes for the liquid refrigerant introduced into the first region to reach the second region is longer than in a case where the resistance member is not provided.

[0066] A compressor according to a third aspect of the present disclosure is the compressor of the second aspect, wherein the resistance member is provided over an entire range around the nozzle.

[0067] Because the resistance member is provided over the entire area around the nozzle, the liquid refrigerant in the lower layer in the first area is less likely to flow into the second area than when the resistance member is provided over only a portion of the area around the nozzle. Also, the time it takes for the liquid refrigerant introduced into the first area to reach the second area is longer than when the resistance member is provided over only a portion of the area around the nozzle.

[0068] A compressor according to a fourth aspect of the present disclosure is the compressor of the third aspect, wherein the resistance member is formed with a hole (97) that connects the inside and outside of the resistance member.

[0069] The resistance member has a hole that connects the inside and outside of the resistance member, so that even if the liquid level temporarily drops below the upper end of the resistance member, the liquid containing at least the lubricating oil can be guided from the first region to the second region, so that even if the liquid level temporarily drops below the upper end of the resistance member, the lubrication of the sliding parts is at least maintained.

[0070] In the compressor according to the fifth aspect of the present disclosure, in the second aspect, a refrigerant introduction point through which refrigerant is introduced into the interior of the housing is provided on the peripheral wall of the housing, and when viewed vertically, the resistance member is provided only in the area between the refrigerant introduction point of the housing and the nozzle.

[0071] When viewed vertically, the resistance member is provided only in the region between the refrigerant introduction portion of the housing and the nozzle, so that the resistance member can be provided only in the path from the first region to the second region where a relatively large amount of refrigerant flows, thereby lengthening the time it takes for the liquid refrigerant introduced into the first region to reach the second region without having to provide resistance members over the entire area around the nozzle.

[0072] A compressor according to a sixth aspect of the present disclosure is the compressor of any one of the second to fifth aspects, wherein an upper end (96) of the resistance member is positioned above a lower end surface of the nozzle.

[0073] Since the upper end of the resistance member is located above the lower end surface of the nozzle, the liquid refrigerant in the lower layer in the first region is less likely to flow into the second region, which reduces the possibility of the lubricating oil containing a large amount of refrigerant being sucked up by the pump unit and supplied to the sliding parts, causing malfunctions in the sliding parts.

[0074] A compressor according to a seventh aspect of the present disclosure is the compressor of any one of the first to sixth aspects, wherein the resistance member is a mesh member.

[0075] The resistance member is a mesh member, so that the liquid refrigerant is easily dissolved into the lubricating oil as it passes through the resistance member (mesh). This cools the lubricating oil and reduces the viscosity of the lubricating oil, thereby reducing friction loss at the sliding parts to which the liquid is supplied.

[0076] DESCRIPTION OF SYMBOLS 1 Scroll compressor (compressor) 10 Housing 11 Upper housing 12 Middle housing 12a Refrigerant introduction point 12b Upper oil return point 12c Lower oil return point 13 Lower housing 13a Bottom surface 20 Discharge cover 21 Outer peripheral end 21a Refrigerant introduction point 22 Discharge port 31 Discharge pipe 32 Suction pipe 33 Injection pipe 34 Oil return pipe 52 Reed valve 53 Retainer 60 Compression mechanism 61 Fixed scroll 62 Fixed side end plate 62a Fixed portion 62b Discharge port 63 Fixed side wall body 65 Orbiting scroll 66 Orbiting side end plate 66a Bearing boss 67 Orbiting side wall body 70 Drive shaft 70a Oil supply passage 71 Main shaft portion 72 Crankshaft portion 75 Electric motor 75a Rotor 75b Stator 80 Support member 81 Journal bearing portion 82 Thrust plate 83 Oil return passage 85 Drive bush 86 Counterweight 87 Journal bearing 91 Lower bearing 93 Pump portion 94 Nozzle 94a Suction port 95 Resistance member 96 Upper end 97 Hole 98 Liquid reservoir C1 Discharge chamber C2 Suction chamber C3 Compression chamber C4 Back pressure chamber R1 First region R2 Second region X Axis

Claims

1. A compressor comprising: a compression mechanism that compresses a refrigerant; a drive shaft extending vertically and driving the compression mechanism; a housing that accommodates the compression mechanism and the drive shaft and has a liquid reservoir formed in its bottom into which the refrigerant and a lubricating oil having a higher temperature and a lower density than the refrigerant are guided; a pump unit that is provided below the drive shaft and sucks up the liquid stored in the liquid reservoir; and a resistance member that is provided at the bottom of the housing and provides resistance to the flow of the liquid stored in the liquid reservoir, wherein the liquid refrigerant and lubricating oil are guided to a first region of the liquid reservoir, and the liquid is sucked up from a second region of the liquid reservoir by the pump unit, and the resistance member is installed between the first region and the second region.

2. The compressor according to claim 1, wherein the pump section has a nozzle whose lower part is submerged in the liquid reservoir, and the resistance member is provided in at least a part of the range around the nozzle.

3. The compressor according to claim 2, wherein the resistance member is provided over the entire periphery of the nozzle.

4. A compressor according to claim 3, wherein the resistance member has a hole formed therein that connects the inside and outside of the resistance member.

5. A compressor as claimed in claim 2, wherein a refrigerant introduction section for introducing refrigerant into the housing is provided on the peripheral wall of the housing, and when viewed vertically, the resistance member is provided only in the region of the housing between the refrigerant introduction section and the nozzle.

6. The compressor according to claim 2, wherein the upper end of the resistance member is located above the lower end surface of the nozzle.

7. A compressor according to claim 1 or 2, wherein the resistance member is a mesh member.

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