Compressor and refrigeration cycle device

Abstract

To provide a compressor and a refrigerating cycle device capable of more uniformly cooling a motor.SOLUTION: The compressor includes a casing in which a suction port through which a refrigerant is sucked is formed, a compression unit that is disposed inside the casing and compresses the refrigerant, a motor that is disposed between the suction port and the compression unit inside the casing and drives the compression unit, and a circular flat plate-shaped strainer that is disposed closer to the suction port side than the motor inside the casing and in which a plurality of openings are formed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a compressor and a refrigeration cycle device. [Background technology]

[0002] Patent Document 1 discloses a screw compressor. The screw compressor has a casing and a motor installed inside the casing. The casing has an intake port through which a refrigerant containing lubricating oil is drawn. A cylindrical strainer is installed at the intake port. Any foreign matter mixed in the refrigerant is removed by the strainer before it flows into the casing from the intake port. This protects the sliding surfaces inside the compressor and the motor from damage caused by foreign matter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5827147 Summary of the Invention [Problem to be solved by the invention]

[0004] The screw compressor uses a cylindrical strainer, which causes the refrigerant flow that passes through the strainer to be biased toward the outer periphery, resulting in uneven cooling of the motor.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a compressor and a refrigeration cycle device that can cool a motor more uniformly. [Means for solving the problem]

[0006] The compressor according to the present disclosure comprises a casing having an intake port through which a refrigerant is drawn, a compression section disposed inside the casing and compressing the refrigerant, a motor disposed inside the casing between the intake port and the compression section and driving the compression section, and a circular, flat strainer disposed inside the casing closer to the intake port than the motor and having a plurality of openings, the strainer having an inner circumferential portion and an outer circumferential portion located outer than the inner circumferential portion, the opening ratio of the inner circumferential portion being greater than the opening ratio of the outer circumferential portion.

[0007] A refrigeration cycle device according to the present disclosure includes a compressor according to the present disclosure. [Effects of the Invention]

[0008] According to the present disclosure, the motor can be cooled more uniformly. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing the configuration of a compressor according to a first embodiment. [Figure 2] 2 is a front view showing the configuration of a cover casing of the compressor according to the first embodiment. FIG. [Figure 3] 1 is a front view showing a schematic configuration of a strainer of a compressor according to a first embodiment. [Figure 4] 1 is a cross-sectional view showing the configuration of a motor rotor of a compressor according to a first embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing the VV cross section of FIG. [Figure 6] FIG. 4 is a cross-sectional view showing a configuration of a motor rotor of a compressor according to a modified example of the first embodiment. [Figure 7] 2 is a cross-sectional view showing a flow path of a refrigerant in a motor portion of the compressor according to the first embodiment. FIG. [Figure 8] FIG. 10 is a front view showing a schematic configuration of a strainer of a compressor according to a second embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing the configuration of a motor rotor of a compressor according to a third embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing the configuration of a motor rotor of a compressor according to a third embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing the configuration of a compressor according to a fourth embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing the XII-XII cross section of FIG. [Figure 13] FIG. 10 is a diagram showing a refrigerant circuit of a refrigeration cycle device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiments of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to the following embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the following embodiments. In particular, the combinations of components are not limited to the combinations in each embodiment; components described in one embodiment can be applied to another embodiment. In the following description, directional terms (e.g., "up," "down," "right," "left," "front," "rear," etc.) are used as appropriate to facilitate understanding, but these are for explanatory purposes and do not limit the present disclosure. In each drawing, components designated with the same reference numerals are identical or equivalent, and this applies throughout the entire specification. Note that the relative dimensional relationships or shapes of each component in each drawing may differ from those in reality.

[0011] Embodiment 1 A compressor and a refrigeration cycle device according to a first embodiment will be described. Fig. 1 is a cross-sectional view showing the configuration of a compressor according to this embodiment. The left-right direction in Fig. 1 represents the axial direction of the compressor 1, i.e., the axial direction of the screw shaft 13. Solid arrows in Fig. 1 represent the flow of a refrigerant. In this embodiment, a screw compressor is exemplified as the compressor 1.

[0012] As shown in Fig. 1, the compressor 1 has a compressor main body 10 and an oil separator 20. The oil separator 20 is fastened to a casing 11 of the compressor main body 10 with bolts (not shown). Although a demister-type oil separator is shown here, a cyclone-type oil separator may also be used. The oil separator may also be provided in the refrigeration cycle device rather than in the compressor.

[0013] The compressor main body 10 comprises a cylindrical casing 11, a motor 12 housed within the casing 11, a screw shaft 13 rotated by the motor 12, a screw rotor 14 fixed to the screw shaft 13, and a strainer 80.

[0014] The casing 11 has a motor casing 50 that houses the motor 12, a cover casing 60, and a suction casing 70. The suction casing 70 has a suction port 70a formed therein through which a refrigerant is drawn. A refrigerant suction pipe (not shown) is connected to the suction port 70a from the outside. The casing 11 has a configuration in which the motor casing 50, the cover casing 60, and the suction casing 70 are arranged in this order in the axial direction of the screw shaft 13.

[0015] The screw rotor 14 is cylindrical, and has a plurality of screw grooves 14a formed on its outer circumferential surface, each extending helically from one end to the other. One end of the screw rotor 14 serves as the refrigerant gas intake side, with the screw grooves 14a communicating with the suction pressure side. The other end of the screw rotor 14 serves as the refrigerant gas discharge side, with the screw grooves 14a communicating with the discharge pressure side.

[0016] A pair of gate rotors 15 are arranged on the side of the screw rotor 14 so as to be axially symmetrical with respect to the screw shaft 13. A cylindrical slide valve 16 is arranged between the side of the casing 11 and the screw rotor 14. The screw rotor 14 and the gate rotor 15 constitute the compression section of the compressor 1.

[0017] The gate rotor 15 is disk-shaped and has a plurality of teeth 15a formed along the circumferential direction on its outer circumferential surface. The teeth 15a of the gate rotor 15 are arranged to mesh with the screw grooves 14a of the screw rotor 14. A compression chamber 19 for compressing the refrigerant is formed by a space surrounded by the screw grooves 14a, the teeth 15a of the gate rotor 15, the inner circumferential surface of the casing 11, and the slide valve 16. Oil for lubricating the bearings 17 and sealing the compression chamber 19 flows into the compression chamber 19 together with the refrigerant. The refrigerant compressed in the compression chamber 19 flows into the oil separator 20, where it is separated into the refrigerant and oil.

[0018] The slide valve 16 is provided along the outer peripheral surface of the screw rotor 14 so as to be slidable in the axial direction of the screw rotor 14. An opening 16a is formed in the center of the slide valve 16 in the sliding direction. The slide valve 16 may be used for mechanical capacity control, or may be used for changing the internal volume by changing the timing of discharge.

[0019] The motor 12 has a motor stator 12a fixed in a state inscribed within the motor casing 50, and a motor rotor 12b arranged inside the motor stator 12a. The motor rotor 12b is fixed to the screw shaft 13 and arranged on the same line as the screw rotor 14. The radius of the motor rotor 12b, i.e., the distance between the central axis 13a of the screw shaft 13 and the outer circumferential surface of the motor rotor 12b, is Ro. The configuration of the motor rotor 12b will be described later using Figures 4 and 5.

[0020] The end of the screw shaft 13 that is not fixed to the motor 12 is rotatably supported by a bearing 17. The end of the screw shaft 13 that is fixed to the motor 12 is rotatably supported by a bearing 18. The rotation speed of the motor 12 can be changed by inverter drive. Note that the motor 12 may also be a constant speed motor that rotates at a constant rotation speed.

[0021] The bearing 18 is housed inside the cover casing 60. The cover casing 60 is connected to the motor casing 50 by bolting, and a sealing part (not shown) such as a gasket or an O-ring is disposed on the joining surface. The cover casing 60 and the casing 11 may be fixed by welding instead of bolting. If welding is used, the sealing part is not required.

[0022] Fig. 2 is a front view showing the configuration of the cover casing of the compressor according to this embodiment. Fig. 2 shows the configuration of the cover casing 60 as viewed along the axial direction of the compressor 1. As shown in Fig. 2, the cover casing 60 has a cover casing main body 61, a bearing holder 62, and a plurality of bearing support portions 63.

[0023] The cover casing body 61 is formed in a cylindrical shape. The bearing holder 62 is disposed on the inner peripheral side of the cover casing body 61 and is provided coaxially with the cover casing body 61. The bearing 18 is attached to the bearing holder 62.

[0024] Each of the bearing support portions 63 extends radially of the cover casing body 61 and connects the cover casing body 61 to the bearing holder 62. As a result, the bearing 18 is supported by the cover casing body 61 via the bearing holder 62 and the plurality of bearing support portions 63. In this embodiment, four bearing support portions 63 are provided, but the number of bearing support portions 63 may be two, three, five or more.

[0025] A plurality of bolt holes 60a are formed in the cover casing 60. The strainer 80 and the suction casing 70 are fixed to the cover casing 60 by fastening bolts through the bolt holes 60a.

[0026] Sealing parts (not shown), such as gaskets and O-rings, are arranged on the joint surfaces between the cover casing 60 and the suction casing 70. The cover casing 60 and the suction casing 70 do not have to be fastened with bolts but may be fixed by welding. If welding is used, sealing parts are not required.

[0027] Strainer 80 is disposed opposite suction port 70a of suction casing 70. Strainer 80 catches foreign matter such as fine dust that is sucked into casing 11 from suction port 70a along with the refrigerant, and serves to prevent seizure of compression chamber 19 and wear of the sliding portion of bearing 18.

[0028] FIG. 3 is a front view showing a schematic configuration of a strainer for a compressor according to this embodiment. FIG. 3 also shows a partial enlarged view of the strainer 80 as viewed along the axial direction of the compressor 1. As shown in FIG. 3, the strainer 80 has a circular, flat plate shape. The strainer 80 is disposed on the upstream side of the cover casing 60 in the refrigerant flow, perpendicular to the axial direction of the compressor 1. The strainer 80 is disposed coaxially with the motor 12. That is, the center portion 80a of the strainer 80 is located on the central axis 13a of the screw shaft 13.

[0029] The strainer 80 has an inner circumferential portion 81 and an outer circumferential portion 82 located more radially outward than the inner circumferential portion 81. The inner circumferential portion 81 is formed in a circular shape centered on a central portion 80a. The outer circumferential portion 82 is formed in an annular shape centered on the central portion 80a. A plurality of openings 81a are formed in the inner circumferential portion 81. A plurality of openings 82a are formed in the outer circumferential portion 82. Each opening 81a and each opening 82a penetrates the strainer 80 along the thickness direction of the strainer 80, i.e., along the axial direction of the compressor 1. Note that in FIG. 3, a solid line is shown at the boundary between the inner circumferential portion 81 and the outer circumferential portion 82, but this boundary is drawn for convenience and there is no actual line.

[0030] When viewed in the axial direction of the compressor 1, the inner circumferential portion 81 and the outer circumferential portion 82 have different opening ratios. The opening ratio of the inner circumferential portion 81 is the ratio of the total area of ​​the multiple openings 81a to the entire area of ​​the inner circumferential portion 81. The opening ratio of the outer circumferential portion 82 is the ratio of the total area of ​​the multiple openings 82a to the entire area of ​​the outer circumferential portion 82. The opening ratio of the inner circumferential portion 81 is larger than the opening ratio of the outer circumferential portion 82. The radius Rf of the inner circumferential portion 81 is equal to or larger than the radius Ro of the motor rotor 12b (Rf≧Ro).

[0031] In this embodiment, the diameter of each opening 81 a is larger than the diameter of each opening 82 a. In this embodiment, the hole shape of each opening 81 a and the hole shape of each opening 82 a are both circular, but the hole shape of each opening 81 a and the hole shape of each opening 82 a may be different.

[0032] FIG. 4 is a cross-sectional view showing the configuration of a motor rotor of a compressor according to this embodiment. FIG. 5 is a cross-sectional view showing a VV cross section of FIG. 4. As shown in FIGS. 4 and 5, the motor rotor 12b is a four-pole permanent magnet (PM) motor rotor having four permanent magnets 90. The motor rotor 12b is also an embedded magnet type PM motor rotor in which each permanent magnet 90 is inserted into an insertion hole 90a of the motor rotor 12b. The four permanent magnets 90 are arranged at equal intervals in the circumferential direction of the motor rotor 12b. Each permanent magnet 90 has a north pole and a south pole. Two adjacent permanent magnets 90 are arranged so that magnetic pole faces with opposite polarities face the outer periphery.

[0033] A plurality of through holes 91 are formed in the motor rotor 12b. Each through hole 91 penetrates the motor rotor 12b in the axial direction. When viewed in the axial direction, each through hole 91 is formed between two permanent magnets 90 that are adjacent to each other in the circumferential direction. The position and shape of each through hole 91 are set so as not to interrupt the magnetic circuit formed in the motor rotor 12b. In this embodiment, each through hole 91 has an elliptical cross section, but each through hole 91 may have a cross section of another shape, such as a circular shape. Furthermore, the diameter of each through hole 91 may be the same as the diameter of the opening 81a formed in the inner periphery 81 of the strainer 80. It is desirable to position each through hole 91 as close to the permanent magnet 90 as possible.

[0034] Fig. 6 is a cross-sectional view showing the configuration of a motor rotor of a compressor according to a modified example of the present embodiment. As shown in Fig. 6, motor rotor 12b is a six-pole PM motor rotor having six permanent magnets 90. In this modified example, each through-hole 91 is formed between two permanent magnets 90 that are adjacent to each other in the circumferential direction. In this way, motor rotor 12b may be a PM motor rotor having a number of poles other than four.

[0035] In the compressor 1 having the above configuration, gas refrigerant or two-phase refrigerant with a high dryness is drawn in through the suction port 70a. The refrigerant drawn in through the suction port 70a passes through the strainer 80 and flows toward the motor 12.

[0036] Fig. 7 is a cross-sectional view showing the refrigerant flow path in the motor portion of the compressor according to this embodiment. As shown in Fig. 7, the refrigerant flows through a space 92 between the casing 11 and the motor stator 12a, a gap 93 between the motor stator 12a and the motor rotor 12b, and a through-hole 91 formed in the motor rotor 12b.

[0037] In this embodiment, the radius Rf of the inner circumferential portion 81 of the strainer 80, which has a large opening ratio, is equal to or greater than the radius Ro of the motor rotor 12b. Therefore, the refrigerant flow passing through the inner circumferential portion 81 of the strainer 80 is actively distributed toward the motor rotor 12b and flows through the through holes 91 and the gaps 93. This increases the flow rate of the refrigerant passing through the motor rotor 12b and increases the heat transfer coefficient from the motor rotor 12b to the refrigerant. This improves the refrigerant's cooling performance of the motor rotor 12b and allows the motor 12 to be cooled more uniformly. On the other hand, if the radius Rf of the inner circumferential portion 81, which has a large opening ratio, is too large, a larger proportion of the refrigerant flows toward the space 92 between the casing 11 and the motor stator 12a, making it difficult for the refrigerant to flow toward the motor rotor 12b. Therefore, it is desirable that the radius Rf of the inner circumferential portion 81 be equal to or less than the outermost diameter of the coil end portion 12a1 of the motor stator 12a (see FIG. 1).

[0038] The refrigerant that has passed through the motor 12 is compressed in the compression chamber 19 and flows out as high-pressure gas refrigerant to the oil separator 20. In the oil separator 20, oil mixed in the refrigerant is separated from the refrigerant, and the refrigerant flows out of the compressor 1.

[0039] As described above, the compressor 1 according to this embodiment includes the casing 11, the screw rotor 14, the gate rotor 15, the motor 12, and the strainer 80. The casing 11 is formed with a suction port 70a through which the refrigerant is drawn. The screw rotor 14 and the gate rotor 15 are an example of a compression section. The compression section is disposed inside the casing 11 and configured to compress the refrigerant.

[0040] The motor 12 is disposed inside the casing 11 between the suction port 70a and the compression section. The motor 12 is configured to drive the compression section. The strainer 80 is disposed inside the casing 11 closer to the suction port 70a than the motor 12. The strainer 80 has a circular flat plate shape. The strainer 80 has a plurality of openings 81a, 82a formed therein. The strainer 80 has an inner circumferential portion 81 and an outer circumferential portion 82 located more outer than the inner circumferential portion 81. The opening ratio of the inner circumferential portion 81 is greater than the opening ratio of the outer circumferential portion 82.

[0041] With this configuration, the opening ratio of the inner peripheral portion 81 of the strainer 80 is greater than the opening ratio of the outer peripheral portion 82, so the refrigerant flow that has passed through the strainer 80 can be directed toward the inner peripheral side of the motor 12 (for example, toward the motor rotor 12b). This prevents the refrigerant from drifting toward the outer peripheral side of the casing, reducing hot spots on the motor 12 and enabling more uniform cooling of the motor 12. Reducing hot spots on the motor 12 reduces the temperature margin, improving the reliability of the compressor 1 equipped with a PM motor. Furthermore, the cost of the compressor 1 can be reduced by switching to a material with lower heat resistance and making the motor more compact.

[0042] Furthermore, by actively directing the refrigerant flow toward the motor rotor 12b, the flow rate of the refrigerant passing through the motor rotor 12b can be increased, thereby improving the heat transfer coefficient from the motor rotor 12b to the refrigerant and the cooling performance of the motor rotor 12b.

[0043] If the motor rotor 12b is not sufficiently cooled, the motor rotor 12b will become hot. In particular, in the case of a PM motor, if a constant current flows through the coil of the motor stator 12a while the motor rotor 12b is at a high temperature, the permanent magnets may be demagnetized, which may result in a deterioration in the operating performance of the compressor 1. In contrast, according to this embodiment, the motor rotor 12b can be efficiently cooled, thereby preventing the permanent magnets from being demagnetized and the resulting deterioration in the operating performance of the compressor 1.

[0044] Conventional cylinder-type strainers have a structure in which the sides of the cylinder are formed with a filter material that allows refrigerant to pass through, and the bottom of the cylinder is closed with a plate. As a result, refrigerant flowing in from the suction port first collides with the bottom of the cylinder, and the refrigerant that bounces back passes through the filter material on the side. This increases pressure loss in the strainer and causes the refrigerant flow to be biased toward the outer periphery of the casing, which can result in inefficient cooling of the motor stator coil end. Furthermore, when the refrigerant flow is biased toward the outer periphery of the casing, oil that accumulates around the outer periphery of the motor stator coil end can obstruct the refrigerant flow.

[0045] In contrast, this embodiment uses a flat strainer 80 with openings 81a and 82a that penetrate in the refrigerant flow direction, thereby reducing pressure loss in strainer 80. Furthermore, the opening ratio of inner peripheral portion 81 is greater than that of outer peripheral portion 82, preventing the refrigerant flow from being biased toward the outer periphery of the casing. Therefore, cooling performance can be maintained even under operating conditions with a low refrigerant circulation rate, where oil is likely to accumulate.

[0046] Furthermore, since the strainer 80 of this embodiment has a flat plate shape, it can be manufactured inexpensively and easily using sheet metal, etc. Therefore, the manufacturing cost of the compressor 1 can be reduced.

[0047] In compressor 1 according to this embodiment, motor 12 has motor stator 12a fixed to casing 11 and motor rotor 12b located radially inward of motor stator 12a. Radius Rf of inner circumferential portion 81 is equal to or greater than radius Ro of motor rotor 12b. With this configuration, the refrigerant flow that has passed through inner circumferential portion 81 of strainer 80 can be more reliably directed toward motor rotor 12b.

[0048] In the compressor 1 according to this embodiment, the motor rotor 12b is a PM motor rotor having permanent magnets 90. The motor rotor 12b is formed with through holes 91 through which a refrigerant flows. With this configuration, the motor rotor 12b can be cooled more efficiently by the refrigerant flowing through the through holes 91.

[0049] Embodiment 2 A compressor according to a second embodiment will be described. The hole shapes of openings 81a and 82a of strainer 80 may be any of a substantially circular, a substantially elliptical, a substantially elongated hole, and a polygonal. Furthermore, openings 81a and 82a may be arranged non-periodically in the circumferential direction of strainer 80.

[0050] Fig. 8 is a front view showing a schematic configuration of the strainer of the compressor according to this embodiment. Fig. 8 shows the positions of bearing holder 62 and bearing support portion 63 when viewed in the axial direction of compressor 1. Bearing holder 62 and bearing support portion 63 are provided downstream of strainer 80 in the flow of refrigerant.

[0051] As shown in Fig. 8, the outer peripheral portion 82 of the strainer 80 has a first portion 82-1 and a second portion 82-2. The first portion 82-1 is a portion that overlaps with the bearing support portion 63 when viewed in the axial direction of the compressor 1. The first portion 82-1 extends along the radial direction of the compressor 1, similar to the bearing support portions 63. The number of first portions 82-1 is the same as the number of bearing support portions 63. The second portion 82-2 is a portion that does not overlap with the bearing support portion 63 when viewed in the axial direction of the compressor 1.

[0052] A plurality of openings 82a (not shown in FIG. 8) are formed in each of the first portion 82-1 and the second portion 82-2. The opening ratio of the first portion 82-1 is greater than the opening ratio of the second portion 82-2. The opening ratio of the first portion 82-1 is the ratio of the total area of ​​the plurality of openings 82a formed in the first portion 82-1 to the entire area of ​​the first portion 82-1. The opening ratio of the second portion 82-2 is the ratio of the total area of ​​the plurality of openings 82a formed in the second portion 82-2 to the entire area of ​​the second portion 82-2. The opening ratio of the first portion 82-1 may be equal to the opening ratio of the inner circumferential portion 81.

[0053] As described above, the compressor 1 according to this embodiment further includes the screw shaft 13, the bearing 18, and the bearing support portion 63. The screw shaft 13 is disposed inside the casing 11 and transmits the driving force of the motor 12 to the compression portion. The screw shaft 13 is an example of a shaft. The bearing 18 rotatably supports the screw shaft 13. The bearing support portion 63 extends radially of the screw shaft 13 and supports the bearing 18 relative to the casing 11. The outer peripheral portion 82 of the strainer 80 has a first portion 82-1 that overlaps with the bearing support portion 63 when viewed in the axial direction of the screw shaft 13, and a second portion 82-2 that does not overlap with the bearing support portion 63 when viewed in the axial direction. The aperture ratio of the first portion 82-1 is greater than the aperture ratio of the second portion 82-2.

[0054] According to this configuration, the flow rate of the coolant passing through the bearing support portion 63 increases, and the coefficient of heat transfer from the bearing support portion 63 to the coolant increases, thereby improving the cooling performance of the bearing 18.

[0055] Embodiment 3 A compressor according to a third embodiment will now be described. Figures 9 and 10 are cross-sectional views showing the configuration of a motor rotor of a compressor according to this embodiment. Figure 9 shows a four-pole PM motor rotor, and Figure 10 shows a six-pole PM motor rotor.

[0056] As shown in FIGS. 9 and 10 , the motor rotor 12b has an insertion hole 90a into which a permanent magnet 90 is inserted. The insertion hole 90a penetrates the motor rotor 12b in the axial direction. In a cross section perpendicular to the axial direction, a through hole 91 in the motor rotor 12b is connected to the insertion hole 90a. When the through hole 91 is provided in the motor rotor 12b, it is desirable to increase the surface area in the axial direction that is in contact with the refrigerant. Specifically, it is desirable that the area of ​​the through hole 91 be larger than the area of ​​the opening 81a. To improve cooling performance, multiple through holes 91 may be arranged. In this case, it is desirable to arrange the through holes 91 in a position that does not affect the magnetic circuit of the motor rotor 12b.

[0057] As described above, in the compressor 1 according to this embodiment, the motor rotor 12b is formed with the insertion holes 90a into which the permanent magnets 90 are inserted. The through holes 91 are connected to the insertion holes 90a. With this configuration, the permanent magnets 90 can be efficiently cooled by the refrigerant flowing through the through holes 91.

[0058] Embodiment 4 A compressor according to a fourth embodiment will be described. Fig. 11 is a cross-sectional view showing the configuration of the compressor according to this embodiment. Fig. 12 is a cross-sectional view showing the XII-XII cross section of Fig. 11. Solid arrows in Fig. 11 indicate the flow of oil.

[0059] As shown in Figures 11 and 12, an oil supply hole 13b is provided in the center of the screw shaft 13 to supply oil from the discharge side to the auxiliary bearing (bearing 17). The temperature of the oil supplied to the auxiliary bearing depends on the type of refrigerant and the operating conditions of the compressor, but is generally medium-low temperature and lower than the coil temperature. In this embodiment, a bearing holder 65 that holds the bearing 17 extends to the vicinity of the motor rotor 12b (at least beyond the tip 12a2 of the coil end portion 12a1). That is, the bearing holder 65 has an extension 65a that extends axially toward the motor 12. The extension 65a extends radially to a position overlapping with the coil end portion 12a1 of the motor stator 12a. As a result, the medium-low temperature oil supplied to the bearing 17 side is actively sprayed onto the motor rotor 12b, cooling the motor rotor 12b.

[0060] Embodiment 5. A refrigeration cycle apparatus according to a fifth embodiment will be described. Fig. 13 is a diagram showing a refrigerant circuit of the refrigeration cycle apparatus according to the present embodiment. As shown in Fig. 13, the refrigeration cycle apparatus 100 includes a compressor 101, a condenser 102, an expansion valve 103 as a pressure reducing device, and an evaporator 104. The compressor 101 uses the compressor 1 according to any one of the first to fourth embodiments.

[0061] In the refrigeration cycle apparatus 100 configured as described above, the compressor 101 draws in, compresses, and then discharges a refrigerant. The gas refrigerant discharged from the compressor 101 flows into the condenser 102, where it exchanges heat with air passing through the condenser 102 and becomes a high-pressure liquid refrigerant, which then flows out. The high-pressure liquid refrigerant that flows out of the condenser 102 is reduced in pressure by the expansion valve 103 and becomes a low-pressure two-phase gas-liquid refrigerant, which then flows into the evaporator 104. The low-pressure two-phase gas-liquid refrigerant that flows into the evaporator 104 exchanges heat with the air passing through the evaporator 104 and becomes a low-pressure gas refrigerant, which is then drawn into the compressor 101 again.

[0062] The refrigeration cycle apparatus 100 configured in this manner can improve its performance by including the compressor 1 according to any one of Embodiments 1 to 4. The refrigeration cycle apparatus 100 can be applied to air conditioners, refrigerator-freezers, etc.

[0063] Various modifications are possible to the above-described embodiments. For example, in the above-described embodiments, a screw compressor is used as the compressor 1, but the compressor may be any compressor other than a screw compressor as long as it is equipped with a motor cooled by a refrigerant.

[0064] Various aspects of the present disclosure are described below.

[0065] (Appendix 1) a casing having a suction port through which a refrigerant is drawn; a compression section disposed inside the casing and compressing the refrigerant; a motor disposed inside the casing between the intake port and the compression unit, the motor driving the compression unit; a circular flat strainer having a plurality of openings, the strainer being disposed inside the casing closer to the intake port than the motor; Equipped with The strainer has an inner peripheral portion and an outer peripheral portion located outer than the inner peripheral portion, The compressor, wherein the aperture ratio of the inner peripheral portion is larger than the aperture ratio of the outer peripheral portion. (Appendix 2) the motor includes a motor stator fixed to the casing and a motor rotor provided radially inward of the motor stator, 2. The compressor according to claim 1, wherein the radius of the inner circumferential portion is equal to or greater than the radius of the motor rotor. (Appendix 3) the motor includes a motor stator fixed to the casing and a motor rotor provided radially inward of the motor stator, the motor rotor is a PM motor rotor having a permanent magnet; 3. The compressor according to claim 1, wherein the motor rotor has a through hole through which the refrigerant flows. (Appendix 4) The motor rotor has an insertion hole into which the permanent magnet is inserted, 4. The compressor according to claim 3, wherein the through hole is connected to the insertion hole. (Appendix 5) a shaft disposed inside the casing and transmitting a driving force of the motor to the compression unit; a bearing that rotatably supports the shaft; a bearing support portion extending in a radial direction of the shaft and supporting the bearing relative to the casing; Furthermore, the outer circumferential portion has a first portion that overlaps with the bearing support portion when viewed in the axial direction of the shaft, and a second portion that does not overlap with the bearing support portion when viewed in the axial direction, 5. The compressor according to any one of claims 1 to 4, wherein the opening ratio of the first portion is larger than the opening ratio of the second portion. (Appendix 6) A refrigeration cycle device comprising the compressor according to any one of Supplementary notes 1 to 5. [Explanation of symbols]

[0066] 1 compressor, 10 compressor body, 11 casing, 12 motor, 12a motor stator, 12a1 coil end portion, 12a2 tip portion, 12b motor rotor, 13 screw shaft, 13a central shaft, 13b oil supply hole, 14 screw rotor, 14a screw groove, 15 gate rotor, 15a tooth portion, 16 slide valve, 16a opening, 17 bearing, 18 bearing, 19 compression chamber, 20 oil separator, 50 motor casing, 60 cover casing, 60a bolt hole, 61 cover casing body, 62 bearing holder, 63 bearing support portion, 65 bearing holder, 65a extension portion, 70 suction casing, 70a suction port, 80 strainer, 80a center portion, 81 inner peripheral portion, 81a opening, 82 outer peripheral portion, 82-1 First part, 82-2 second part, 82a opening, 90 permanent magnet, 90a insertion hole, 91 through hole, 92 space, 93 gap, 100 refrigeration cycle device, 101 compressor, 102 condenser, 103 expansion valve, 104 evaporator.

Claims

1. a casing having a suction port through which a refrigerant is drawn; a compression section disposed inside the casing and compressing the refrigerant; a motor disposed inside the casing between the intake port and the compression unit, the motor driving the compression unit; a circular flat strainer having a plurality of openings, the strainer being disposed inside the casing closer to the intake port than the motor; Equipped with The strainer has an inner peripheral portion and an outer peripheral portion located outer than the inner peripheral portion, The compressor, wherein the aperture ratio of the inner peripheral portion is larger than the aperture ratio of the outer peripheral portion.

2. the motor includes a motor stator fixed to the casing and a motor rotor provided radially inward of the motor stator, 2. The compressor according to claim 1, wherein the radius of the inner circumferential portion is equal to or greater than the radius of the motor rotor.

3. the motor includes a motor stator fixed to the casing and a motor rotor provided radially inward of the motor stator, the motor rotor is a PM motor rotor having a permanent magnet; The compressor according to claim 1 , wherein the motor rotor is formed with a through-hole through which the refrigerant flows.

4. The motor rotor has an insertion hole into which the permanent magnet is inserted, The compressor according to claim 3 , wherein the through hole is connected to the insertion hole.

5. a shaft disposed inside the casing and transmitting a driving force of the motor to the compression unit; a bearing that rotatably supports the shaft; a bearing support portion extending in a radial direction of the shaft and supporting the bearing relative to the casing; Furthermore, the outer circumferential portion has a first portion that overlaps with the bearing support portion when viewed in the axial direction of the shaft, and a second portion that does not overlap with the bearing support portion when viewed in the axial direction, The compressor according to claim 1 , wherein the opening ratio of the first portion is greater than the opening ratio of the second portion.

6. A refrigeration cycle device comprising the compressor according to any one of claims 1 to 5.

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