Compressor, refrigeration cycle device, and rotor

Abstract

The present invention obtains a compressor which reduces the size of a balance weight which cancels imbalance of a centrifugal force occurring in a compression mechanism section and secures a communication path for a refrigerant and a lubricant moving inside the compressor. Provided is a compressor comprising a hermetic container 101; a compression mechanism section 10 that compresses a refrigerant; and an electric motor 20 formed of a stator 5 and a rotor 1 having an axis C as the center of rotation. When a rotor iron core 22 forming the rotor 1 is sectioned to a first iron core section 22a and a second iron core section 22b at an imaginary reference plane V as a boundary plane, first voids 31 are formed in the first iron core section 22a so as to penetrate from one end surface to the other end surface in the axial direction and second voids 32 are formed in the second iron core section 22b so as penetrate from one end surface to the other end surface in the axial direction, each of the second voids 32 being narrower in cross sectional area than each of the first voids 31 on a cross section orthogonal to the axis C.

Description

Compressor, refrigeration cycle device and rotor

[0001] The present disclosure relates to a compressor, a refrigeration cycle device, and a rotor.

[0002] In electric motors for compressors, a configuration in which balance weights are installed on the axial end faces of the rotor to reduce the imbalance of centrifugal force generated in the compression mechanism is known. Balance weights impose dimensional constraints when increasing the output of electric motors or when reducing the size of electric motors, so it is desirable for them to be as small as possible.

[0003] To reduce the size of the balance weight, a method is known in which an air gap is provided in the rotor core asymmetrically with respect to the center of rotation, thereby creating a weight imbalance in the rotor and eliminating the need for a balance weight (see, for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2021-164292

[0005] However, the rotor described in the prior art document does not have a gap that penetrates the axial direction to cause a weight imbalance, and the only path for the refrigerant and lubricating oil to pass through the electric motor is the small gap between the rotor and the stator, which can impede the movement of the refrigerant and lubricating oil, causing an unintended pressure difference inside the compressor and resulting in poor lubrication of the compression mechanism.

[0006] The present disclosure has been made to solve the above-mentioned problems, and provides a compressor that has a smaller balance weight that offsets the imbalance of centrifugal force generated in the compression mechanism, and is equipped with an electric motor that ensures a flow path for the refrigerant and lubricating oil moving inside the compressor.

[0007] In order to achieve the above object, the compressor according to the present disclosure is a compressor including: a sealed container; a compression mechanism unit that is housed in the sealed container and compresses a refrigerant; and an electric motor that is composed of a stator fixed inside the sealed container and a rotor that has a shaft that serves as a rotation axis, and that drives the compression mechanism unit connected via the shaft, wherein the rotor has a rotor core that is cylindrically formed about the rotation axis, and the rotor core is divided into a first core portion and a second core portion by a first plane that includes the rotation axis and is parallel to the rotation axis as a boundary surface, a first void is formed in the first core portion that passes through from one end face to the other end face in the axial direction, and a second void is formed in the second core portion that passes through from one end face to the other end face in the axial direction, and in a cross section perpendicular to the rotation axis, the cross-sectional area of ​​the second void is smaller than the cross-sectional area of ​​the first void.

[0008] The compressor of the present disclosure has a gap through which the rotor passes in the axial direction, which allows the balance weight used to offset the imbalance of centrifugal force generated in the compression mechanism to be made smaller, and the movement of refrigerant and lubricating oil inside the compressor is hindered, thereby suppressing the occurrence of unintended pressure differences.

[0009] Fig. 1 is a cross-sectional view showing the configuration of a compressor according to embodiment 1. Fig. 2 is a cross-sectional view showing the configuration of a rotor according to embodiment 1. Fig. 3 is a longitudinal cross-sectional view showing the configuration of a rotor according to embodiment 1. Fig. 4 is a perspective view showing the configuration of a rotor according to embodiment 1. Fig. 5 is a magnetic flux line diagram schematically showing the flow of magnetic flux inside a rotor core according to embodiment 1. Fig. 6 is a longitudinal cross-sectional view showing the configuration of a rotor according to embodiment 2. Fig. 7 is a cross-sectional view showing the configuration of a rotor according to embodiment 2. Fig. 8 is a longitudinal cross-sectional view showing the configuration of a rotor according to embodiment 3. Fig. 9 is a diagram showing the configuration of a refrigeration cycle device according to embodiment 4.

[0010] Hereinafter, a compressor, a refrigeration cycle device, and a rotor according to embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the following embodiments are merely examples, and various modifications are possible within the scope of the present disclosure.

[0011] To facilitate understanding of the relationships between the drawings, each figure shows an xyz Cartesian coordinate system. The z-axis is a coordinate axis parallel to the axis C, which is the center of rotation of the rotor 1. The x-axis is a coordinate axis perpendicular to the z-axis. The y-axis is a coordinate axis perpendicular to both the x-axis and the z-axis.

[0012] Embodiment 1 <Compressor> Fig. 1 is a cross-sectional view showing the configuration of a compressor according to embodiment 1. As shown in Fig. 1, compressor 100 is a scroll-type compressor, and includes a compression mechanism 10, an electric motor 20, and a subframe 102 housed in a sealed container 101.

[0013] The compression mechanism 10 compresses the refrigerant. The electric motor 20 drives the compression mechanism 10. The electric motor 20 is connected to the compression mechanism 10 by a shaft 21. The electric motor 20 is, for example, a permanent magnet synchronous motor. The shaft 21 extends in the z-axis direction.

[0014] The sealed container 101 is a container that houses the compression mechanism 10 and the electric motor 20. The sealed container 101 is provided with a suction pipe 105 that draws refrigerant into the compression mechanism 10 from the outside, and a discharge pipe 103 that discharges high-pressure refrigerant discharged from the compression mechanism 10 to the outside of the compressor 100. In addition, a glass terminal 104 that supplies power to the electric motor 20 is fixed to the sealed container 101. The glass terminal 104 is fixed to the sealed container 101 by, for example, welding. The subframe 102 supports the end of the shaft 21 of the electric motor 20 on the −z axis side.

[0015] The compression mechanism 10 is composed of a fixed scroll 11, an orbiting scroll 12, a compliance frame 13, and a guide frame 14. In the compression mechanism 10, a compression chamber is formed by meshing the spiral portion of the fixed scroll 11 with the spiral portion of the orbiting scroll 12. The compliance frame 13 supports the end of the shaft 21 on the +z-axis side. The guide frame 14 is fixed to the sealed container 101 and supports the compliance frame 13.

[0016] The electric motor 20 is composed of a rotor 1 and a stator 5. The stator 5 has a stator core 51 and windings 52 wound around teeth (not shown) of the stator core 51. The rotation of the electric motor 20 is transmitted to the orbiting scroll 12 through the shaft 21. The compression mechanism 10 changes the volume of the compression chamber by the orbiting motion of the orbiting scroll 10, and compresses the refrigerant flowing in from the suction pipe 105. The compressed refrigerant flows out of the compressor 100 from the discharge pipe 103.

[0017] <Rotor> Next, the configuration of the rotor 1 will be described in detail. Fig. 2 is a cross-sectional view showing the configuration of the rotor 1 according to embodiment 1. Fig. 3 is a longitudinal-sectional view showing the configuration of the rotor 1 according to embodiment 1. Fig. 4 is a perspective view showing the configuration of the rotor 1 according to embodiment 1. Fig. 4 is a view excluding the shaft 21. As shown in Figs. 2 to 4, the rotor 1 has the shaft 21 as a rotation axis, a rotor core 22 formed in a cylindrical shape centered on the rotation axis, a balance weight 23 provided on the rotor core 22, and a permanent magnet 24. Note that the balance weight 23 is not shown in Fig. 2.

[0018] In the following description, the direction along the circumference of a circle centered on the axis C of the shaft 21 (see, for example, FIG. 2) (for example, the direction indicated by the arrow in FIG. 2) is referred to as the "circumferential direction R," the direction in which the shaft 21 extends is referred to as the "axial direction," and the direction in which a straight line passing through the shaft 21 and perpendicular to the axial direction extends is referred to as the "radial direction." Furthermore, a "transverse cross-sectional view" is a cross-sectional view taken along a plane perpendicular to the axis C, and a "longitudinal cross-sectional view" is a cross-sectional view taken along a plane parallel to the axis C.

[0019] The balance weight 23 is provided to offset the imbalance of centrifugal force generated by the rotation of the shaft 21 having an eccentric portion for oscillating the orbiting scroll 12. The balance weight 23 is made of a non-magnetic material such as brass.

[0020] 2, the rotor 1 has a substantially circular cross section, and the shaft 21 is disposed at the center of rotation. The rotor 1 is composed of a rotor core 22 having a shaft insertion hole 34 at the center of rotation, and the shaft 21 inserted into the shaft insertion hole 34.

[0021] The rotor core 22 has a plurality of (e.g., six) magnet insertion holes 25 spaced equally apart in the circumferential direction R. A permanent magnet 24 is inserted into each of the magnet insertion holes 25. Since one permanent magnet 24 forms one magnetic pole, the rotor 1 shown in this embodiment 1 has six poles. In this way, the rotor 1 is a permanent magnet embedded rotor. The number of poles of the rotor 1 is not limited to six, as long as it is two or more. Furthermore, multiple permanent magnets 24 may be inserted into one magnet insertion hole 25.

[0022] The permanent magnet 24 is, for example, a rare earth magnet, specifically, a neodymium sintered magnet containing neodymium (Nd), iron (Fe), and boron (B). Note that the permanent magnet 24 is not limited to a neodymium sintered magnet, and may be, for example, any one of a samarium-cobalt magnet, a ferrite magnet, and a bonded magnet.

[0023] The rotor 22 also includes a plurality of flux barriers 25a. The plurality of flux barriers 25a are part of the magnet insertion hole 25 and are formed at both ends of the magnet insertion hole 25. The flux barriers 25a form thin-walled portions near the outer circumferential surface of the rotor core 22, and therefore can suppress short-circuiting of the magnetic flux of the permanent magnets 24 between magnetic poles adjacent in the circumferential direction R.

[0024] The rotor core 22 is formed by stacking multiple electromagnetic steel sheets in the z-axis direction. The thickness of each electromagnetic steel sheet is determined to be within a range of 0.1 mm to 0.5 mm, for example. In the first embodiment, the thickness of each electromagnetic steel sheet is 0.35 mm. The multiple electromagnetic steel sheets are fixed to one another by crimping. Therefore, the rotor core 22 has multiple crimped portions 33.

[0025] 2, the rotor core 22 is divided into a first core portion 22a and a second core portion 22b by an imaginary plane V that includes the axis C, which is a first plane. The imaginary plane V that divides the first core portion 22a and the second core portion 22b is called the reference plane V. The first core portion 22a is provided with a first air gap 31 that penetrates the rotor core 22 in the z-axis direction. Similarly, the second core portion 22b is provided with a second air gap 32 that penetrates the rotor core 22 in the z-axis direction and has a smaller cross-sectional area than the first air gap 31. The first air gap 31 and the second air gap 32 are formed by holes formed in electromagnetic steel plates.

[0026] In the rotor core 22 shown in Fig. 3, the right half of the page is the first core portion 22a, and the left half is the second core portion 22b, with the reference plane V as the boundary. The first core portion 22a has a larger air gap than the second core portion 22b, and therefore is lighter in weight than the second core portion 22b. In other words, in Fig. 3, the center of gravity of the rotor core 22 is biased toward the second core portion 22b.

[0027] End plates 26 are fixed to both sides of the axial end face of the rotor core 22. As shown in Figures 3 and 4, the end plates 26 are provided with communication holes 27 so that the first air gap 31 and the second air gap 32 are not blocked. The communication holes 27 have the same shape as the first air gap 31 or are larger than the first air gap 31, and are formed so as to include the first air gap 31 and the second air gap 32.

[0028] Additionally, a balance weight 23 is fixed to the second core portion 22b via an end plate 26. The balance weight 23 is installed so as to further increase the degree of eccentricity of the center of gravity caused by the weight difference between the first core portion 22a and the second core portion 22b.

[0029] The position and weight of the balance weight 23 are determined by the degree of eccentricity of the compression mechanism 10 connected to the shaft 21, and are not limited to the position in this embodiment. Furthermore, if the weight imbalance applied to the rotor core 22 can completely offset the imbalance in centrifugal force generated in the compression mechanism 10, the balance weight 23 may not be installed.

[0030] 3 and 4, the balance weight 23 also has a through-hole 35 formed therein that penetrates in the z-axis direction so as to communicate with the first air gap 31 or the second air gap 32. The through-hole 35 is formed so that the first air gap 31 or the second air gap 32 is not blocked even when the balance weight 23 is installed in the rotor core 22.

[0031] Fig. 5 is a magnetic flux line diagram that schematically shows the flow of magnetic flux inside the rotor core 22. The first core portion 22a shown in Fig. 5 includes three permanent magnets 24 extending in the circumferential direction R and three corresponding first air gaps 31. If the midpoint of each permanent magnet 24 in the circumferential direction R is defined as the magnetic pole center, then line M in Fig. 5 is a line on the xy plane that connects the axis C and the magnetic pole center of each permanent magnet 24, and will hereinafter be referred to as the "magnetic pole center line."

[0032] 5, the magnetic flux density inside the rotor core 22 is dense in the region between two adjacent permanent magnets 24 in the circumferential direction R, and is sparse near the magnetic pole center. Therefore, the region along the magnetic pole center line M plays a smaller role as a magnetic path than the region between the adjacent permanent magnets 24 in the circumferential direction R.

[0033] It is known that gaps provided in rotor core 22 obstruct the flow of magnetic flux and increase iron loss. On the other hand, in order to reduce the size of balance weight 23, it is preferable that the degree of eccentricity of the center of gravity of rotor core 22 is large. In other words, the cross-sectional area of ​​first gap 31 is preferably as large as possible without obstructing the flow of magnetic flux within rotor core 22. On the other hand, the cross-sectional area of ​​second gap 32 is preferably as small as possible without obstructing the flow of refrigerant passing through rotor core 22 in the axial direction within sealed container 101.

[0034] Therefore, the side surface that forms the first air gap 31 and is closest to the outer peripheral surface of the rotor 22 is formed so that it is closest to the magnetic pole center on the magnetic pole center line M, and the farther it is from the permanent magnet 24 the farther it is from the magnetic pole center line M in the circumferential direction R. In other words, the first air gap 31 is formed in a convex shape toward the magnetic pole center, which is the midpoint of the circumferential direction R of the permanent magnet 24. In the first core portion 22a, by forming the first air gap 31 in the above-mentioned shape, it can be formed as large as possible without affecting iron loss.

[0035] <Effects of First Embodiment> According to the first embodiment described above, first core portion 22a of rotor core 22 is provided with first gap 31 penetrating in the z-axis direction, and second core portion 22b is provided with second gap 32 penetrating in the z-axis direction and having a smaller cross-sectional area than first gap 31. As a result, electric motor 20 does not obstruct the movement of refrigerant and lubricating oil within compressor 100, and the efficiency and reliability of compressor 100 are not reduced.

[0036] Furthermore, the first gap 31 and the second gap 32, which have different cross-sectional areas, provide a weight imbalance to the rotor core 22, thereby offsetting the imbalance in centrifugal force generated by the rotation of the compression mechanism 10.

[0037] Furthermore, by providing a balance weight 23 in addition to the above configuration to impart a weight imbalance to the rotor 1, it is possible to offset the imbalance of the centrifugal force generated by the rotation of the compression mechanism 10. In this case, since a weight imbalance occurs in the rotor core 22 due to the first air gap 31 and the second air gap 32, the balance weight 23 can be made smaller.

[0038] Furthermore, according to the first embodiment, the radially outer side surface of the first air gap 31 is formed so as to be closest to the permanent magnet 24 on the magnetic pole center line M, and to be further away from the permanent magnet 24 as it moves away from the magnetic pole center line M in the circumferential direction R. This allows the first air gap 31 to be formed large within a range that does not increase iron loss, and a larger weight imbalance can be imparted to the rotor 1. This allows the balance weight 23 to be made smaller.

[0039] Furthermore, in rotor core 22, electromagnetic steel sheets are laminated so that one side divided by reference plane V is entirely first core portion 22a and the other side is entirely second core portion 22b, thereby maximizing the weight imbalance of rotor 1. Therefore, balance weight 23 can be made even more compact.

[0040] Furthermore, the compressor can be made lighter and smaller by reducing the size of the balance weight 23. Furthermore, restrictions on the size of the rotor are reduced, making it easier to improve the output of the electric motor.

[0041] Embodiment 2 Fig. 6 is a longitudinal cross-sectional view showing the configuration of a rotor 2 according to embodiment 2. In Fig. 6, components that are the same as or correspond to those shown in Fig. 3 are assigned the same reference numerals as those shown in Fig. 3. The rotor 2 according to embodiment 2 has an inversion plane H1, which is a second plane perpendicular to the z-axis, on the rotor core 22.

[0042] On the upper side of the inversion surface H1, which is the first layer, the first core portion 22a is on the right side of the reference plane V including the axis C, and the second core portion 22b is on the left side. On the other hand, on the lower side of the inversion surface H1, which is the second layer, the second core portion 22b is on the right side of the reference plane V including the axis C, and the first core portion 22a is on the left side. That is, in the rotor 2, the electromagnetic steel sheets that form the rotor core 22 above and below the inversion surface H1 are stacked while being rotated 180 degrees around the axis C.

[0043] In the rotor core 22 configured in this manner, the first layer above the inversion surface H1 is heavier on the left side of the reference plane V in Fig. 6 due to the weight difference between the first core portion 22a and the second core portion 22b and the balance weight 23. On the other hand, the second layer below the inversion surface H1 is heavier on the right side of the reference plane V in Fig. 6 due to the weight difference between the first core portion 22a and the second core portion 22b. In other words, a weight imbalance is also created in the z-axis direction. The weight imbalance created in the z-axis direction can offset the even imbalance that causes the wobbly vibration of the shaft 21 caused by the rotation of the rotor 2.

[0044] Fig. 7 is a cross-sectional view showing the configuration of the rotor 2 according to embodiment 2. In Fig. 7, the first air gaps 31 and the second air gaps 32 formed in the first layer are shown by solid lines, and the first air gaps 31 and the second air gaps 32 formed in the second layer are shown by dashed lines.

[0045] 7 , when the electromagnetic steel sheets forming the rotor core 22 are stacked by rotating them 180 degrees around the axis C from an inversion plane H1 set midway in the z-axis direction, the first voids 31 are arranged to enclose the second voids 32. That is, in the rotor 2, the first voids 31 and the second voids 32 communicate from one end face to the other end face of the rotor core 22. Therefore, the rotor 2 does not hinder the movement of the refrigerant and lubricating oil inside the compressor 100.

[0046] Furthermore, the multiple magnet insertion holes 25 and crimped portions 33 provided in the electromagnetic steel sheets forming the rotor core 22 are arranged at equal intervals in the circumferential direction R so that they overlap in the same position even when the electromagnetic steel sheets are rotated 180 degrees around the axis C and stacked. Therefore, the insertion of permanent magnets 24 and the stacking of the electromagnetic steel sheets can be carried out without any problems.

[0047] Effect of Embodiment 2 As described above, according to Embodiment 2, it is possible to obtain the same effect as that shown in Embodiment 1. That is, a weight imbalance occurs in rotor core 22 due to the difference in cross-sectional area between first gap 31 provided in first core portion 22 a and second gap 32 provided in second core portion 22 b in rotor core 22, and this can offset the imbalance in centrifugal force generated by the rotation of compression mechanism 10.

[0048] Furthermore, since the weight distribution of the rotor core 22 can be adjusted in the z-axis direction depending on the position of the inverted surface H1 in the z-axis direction, the even unbalance of the rotor 2 can also be offset. This allows the balance weight 23 to be made more compact. Even unbalance refers to a weight imbalance in the z-axis direction that causes a wobbling motion when the rotor 2 is rotating.

[0049] Also in the second embodiment, the first gap 31 and the second gap 32 are formed so as to be connected in the z-axis direction, so that the movement of the refrigerant and lubricating oil within the compressor 100 is not hindered and the efficiency of the compressor is not reduced.

[0050] Furthermore, in rotor 2, first core portion 22a and second core portion 22b constituting rotor core 22 are in a point-symmetric relationship, and electromagnetic steel sheets of the same shape are laminated by rotating them 180 degrees, so there is no need to use multiple types of electromagnetic steel sheets. Therefore, only one die is required for manufacturing the electromagnetic steel sheets by punching, which reduces manufacturing costs.

[0051] Embodiment 3 Figure 8 is a longitudinal cross-sectional view showing the configuration of a rotor 3 according to embodiment 3. In Figure 8, components that are the same as or correspond to those shown in Figure 3 are assigned the same reference numerals as those shown in Figure 3. The rotor 3 according to embodiment 3 has an inversion surface H2, which is a third flat surface, in parallel to an inversion surface H1, which is a surface perpendicular to the z-axis, on the rotor core 22.

[0052] In the rotor core 22 that constitutes the rotor 3, above the inversion surface H1, which is the first layer, the first core portion 22a is on the right side of the reference plane V, and the second core portion 22b is on the left side of the reference plane V. The lower side of the inversion surface H1, which is the second layer, is further divided into upper and lower portions by the inversion surface H2, and like the first layer, the lower side of the inversion surface H2, is such that the first core portion 22a is on the right side of the reference plane V and the second core portion 22b is on the left side. Meanwhile, in the portion sandwiched between the inversion surfaces H1 and H2, which are the upper layers, the second core portion 22b is on the right side of the reference plane V, and the first core portion 22a is on the left side.

[0053] Also, in rotor 3, as in rotor 2, the first voids 31 and second voids 32 provided in the upper and lower layers of the first and second layers that make up rotor core 22 are arranged so as to penetrate rotor core 22 in the axial direction.

[0054] With this configuration, the rotor 3 can be given an appropriate weight difference between the right and left sides of the reference plane V shown in Figure 8, and the weight distribution in the z-axis direction can also be freely adjusted. Other functions are the same as those of the rotor 2 described in the second embodiment.

[0055] <Effects of Embodiment 3> As described above, according to Embodiment 3, it is possible to obtain the same effects as those shown in Embodiments 1 and 2. That is, by generating a weight imbalance in rotor core 22, it is possible to offset the imbalance in centrifugal force generated by the rotation of compression mechanism 10.

[0056] Furthermore, the rotor 3 can adjust the weight distribution of the rotor core 22 more precisely than the rotor 2 described in embodiment 2 depending on the positions of the inversion surfaces H1 and H2 in the z-axis direction. This allows the rotor 3 to position the center of gravity on the axis C and also offset the even imbalance. This allows the balance weight 23 to be made smaller.

[0057] Also in the third embodiment, the first void 22a and the second void 22b are formed to be connected in the z-axis direction, so that the flow of refrigerant within the compressor 100 is not obstructed and the efficiency of the compressor is not reduced.

[0058] Furthermore, in the rotor 3, the first core portion 22a and the second core portion 22b constituting the rotor core 22 are in a point-symmetric relationship, so there is no need to use multiple types of electromagnetic steel sheets. As a result, only one die is required to manufacture the electromagnetic steel sheets by punching, which reduces manufacturing costs.

[0059] 9 is a diagram showing the configuration of a refrigeration cycle apparatus 300 according to embodiment 4. In embodiment 4, a refrigeration cycle apparatus 300 equipped with a refrigeration cycle including the compressor 100 described in embodiment 1 will be described.

[0060] In the fourth embodiment, the refrigeration cycle apparatus 300 is an air conditioner including an outdoor unit 71 and an indoor unit 72. The outdoor unit 71 and the indoor unit 72 are connected by a refrigerant pipe 73 to form a closed refrigerant circuit. This refrigerant circuit is filled with R32, an HFC refrigerant, as the working refrigerant. The refrigerant filled in this refrigerant circuit is not limited to R32, and may be R290, a natural refrigerant, or a mixed refrigerant containing carbon dioxide or the like.

[0061] The outdoor unit 71 incorporates a compressor 100, an outdoor heat exchanger 74, an expansion valve 75, and an outdoor blower 76. The compressor 100 is equipped with an inverter device that continuously changes its operating frequency, making it possible to increase or decrease the flow rate of refrigerant circulating through the refrigerant circuit. The refrigeration cycle apparatus 300 can precisely adjust the air conditioning capacity by controlling the operating frequency of the compressor 100.

[0062] The outdoor heat exchanger 74 exchanges heat between the high-temperature, high-pressure gas refrigerant discharged from the compressor 100 and outdoor air. The outdoor blower 76 adjusts the amount of heat exchanged by the outdoor heat exchanger 74 by adjusting the amount of air sent out. The refrigerant dissipates heat into the outdoor air in the outdoor heat exchanger 74 and becomes liquefied, and is then decompressed by the expansion valve 75 to become a low-pressure two-phase refrigerant.

[0063] The low-pressure, low-temperature two-phase refrigerant decompressed by the expansion valve 75 flows into the indoor unit 72 via the refrigerant pipe 73. The indoor unit 72 exchanges heat between the flowing two-phase refrigerant and indoor air supplied from an indoor blower 78 in an indoor heat exchanger 77. The low-temperature, low-pressure two-phase refrigerant is heated by the indoor air and evaporates, becoming low-pressure gas refrigerant and flowing out of the indoor unit 72.

[0064] The gas refrigerant that flows out of the indoor unit 72 returns to the outdoor unit 71 and is again sucked into the compressor 100. In Fig. 9, the refrigeration cycle apparatus 300 is an air conditioner for cooling only, with the outdoor heat exchanger 74 as a condenser and the indoor heat exchanger 77 as an evaporator, but is not limited to this. For example, if four-way switching valves are disposed before and after the compressor 100 to enable switching between the discharge side and the suction side of the compressor 100, a refrigeration cycle apparatus that can select between cooling and heating can be configured.

[0065] <Effects of Embodiment 4> As described above, the refrigeration cycle apparatus 300 described in Embodiment 4 includes a refrigerant circuit including the compressor 100 described in Embodiment 1. As described above, the compressor 100 can suppress a decrease in efficiency by including the electric motor 20. Therefore, the refrigeration cycle apparatus 300 can also suppress a decrease in efficiency.

[0066] Furthermore, since the balance weight 23 of the compressor 100 can be made smaller, the refrigeration cycle device 300 can also be made smaller and lighter.

[0067] The configurations shown in the above embodiments are examples of the content of the present invention, and may be combined with other known technologies, and some of the configurations may be omitted or modified within the scope of the gist of the present invention.

[0068] DESCRIPTION OF SYMBOLS 1, 2, 3 Rotor, 5 Stator, 51 Stator core, 52 Winding, 10 Compression mechanism, 11 Fixed scroll, 12 Swing scroll, 13 Compliance frame, 14 Guide frame, 20 Electric motor, 21 Shaft, 22 Rotor core, 22a First core portion, 22b Second core portion, 23 Balance weight, 24 Permanent magnet, 25 Magnet insertion hole, 26 End plate, 27 Communication hole, 31 First gap, 32 Second gap, 33 Crimped portion, 34 Shaft insertion hole, 35 Through hole, 71 Outdoor unit, 72 Indoor unit, 73 Refrigerant piping, 74 Outdoor heat exchanger, 75 Expansion valve, 76 Outdoor blower, 77 Indoor heat exchanger, 78 Indoor blower, 100 Compressor, 101 sealed container, 102 subframe, 103 discharge pipe, 104 glass terminal, 105 suction pipe, 300 refrigeration cycle device, C axis, V reference plane, M magnetic pole center line, H1, H2 inversion plane

Claims

1. A hermetic container, a compression mechanism part built in the hermetic container and compressing a refrigerant, and an electric motor including a stator fixed inside the hermetic container and a rotor having a shaft serving as a rotating shaft, the electric motor driving the compression mechanism part connected via the shaft. The compressor is provided with: The rotor includes a rotor core centered on the rotating shaft. When the rotor core includes the rotating shaft and is divided into a first core part and a second core part with a first plane parallel to the rotating shaft and including the rotating shaft as a boundary surface, a first gap penetrating from one end face to the other end face in the axial direction of the rotating shaft is formed in the first core part, a second gap penetrating from one end face to the other end face in the axial direction is formed in the second core part, In a cross section orthogonal to the rotating shaft, the cross-sectional area of the second gap is smaller than the cross-sectional area of the first gap. Compressor.

2. The rotor core includes a balance weight fixed to one end face or the other end face of the rotor core. The balance weight has a through hole penetrating in the axial direction and formed to communicate with the first gap or the second gap. The compressor according to Claim 1.

3. The rotor core is formed by laminating a plurality of electromagnetic steel sheets in the axial direction. The electromagnetic steel sheet has a hole forming the first gap and a hole forming the second gap. From one end face to the other end face of the rotor core, one part divided by the first plane is entirely the first core part. The compressor according to Claim 1, wherein the other part divided by the first plane is entirely the second core part and is laminated in such a manner.

4. The rotor core is formed by laminating a plurality of electromagnetic steel sheets in the axial direction. The electromagnetic steel sheet has a hole forming the first gap and a hole forming the second gap. From one end face to the other end face of the rotor core, one part divided by the first plane is entirely the first core part. The compressor according to Claim 2, wherein the other part divided by the first plane is entirely the second core part and is laminated in such a manner.

5. The rotor core is divided into a first layer and a second layer with a second plane orthogonal to the rotating shaft as a boundary surface. The second layer is laminated with electromagnetic steel sheets rotated 180 degrees around the rotating shaft with respect to the first layer. The first void provided in the first layer communicates axially with the second void provided in the second layer. The second void provided in the first layer communicates axially with the first void provided in the second layer. The compressor according to claim 1.

6. The rotor core is divided into a first layer and a second layer with a second plane perpendicular to the rotation axis as a boundary surface. The second layer is rotated 180 degrees about the rotation axis with respect to the first layer, and electromagnetic steel sheets are laminated. The first void provided in the first layer communicates axially with the second void provided in the second layer. The second void provided in the first layer communicates axially with the first void provided in the second layer. The compressor according to claim 2.

7. The second layer is divided into an upper layer that contacts the first layer and a lower layer that does not contact the first layer by a third plane that is perpendicular to the rotation axis and different from the second plane. The first void provided in the first layer communicates axially with the second void provided in the upper layer and the first void provided in the lower layer. The second void provided in the first layer communicates axially with the first void provided in the upper layer and the second void provided in the lower layer. The compressor according to claim 6.

8. The rotor core includes a plurality of permanent magnets on the outer peripheral side of the first void and the second void. Each of the permanent magnets forms a magnetic pole on the outer peripheral surface of the rotor core. The first void is formed in a convex shape toward the center of the magnetic pole in a cross section perpendicular to the rotation axis. The compressor according to any one of claims 1 to 7.

9. A compressor according to any one of claims 1 to 7, a condenser that condenses the refrigerant discharged from the compressor, a decompression device that decompresses the refrigerant condensed by the condenser, an evaporator that evaporates the refrigerant decompressed by the decompression device, and a refrigeration cycle device including the same.

10. A rotor that forms an electric motor together with a stator, wherein the rotor includes a rotor core centered on the rotation axis of the rotor, when the rotor core is divided into a first core portion and a second core portion with a first plane that includes the rotation axis and is parallel to the rotation axis as a boundary surface, a first void that penetrates from one end surface to the other end surface in the axial direction of the rotation axis is formed in the first core portion. A second air gap penetrating from one end face to the other end face in the axial direction is formed in the second iron core portion. In a cross section orthogonal to the rotation axis, the cross-sectional area of the second air gap is smaller than the cross-sectional area of the first air gap. The rotor is characterized by this.