Rotating electrical machines, compressors, and refrigeration equipment

Abstract

To suppress gaps between a stator and a rotor from being uneven.SOLUTION: The radial rigidity per unit axial length of a core (32) in the circumferential range and the axial range of a portion to which compressive stress is applied is higher than the radial rigidity per unit axial length of the entire core (32) in the circumferential range.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to rotating electrical machines, compressors, and refrigeration systems. [Background technology]

[0002] Patent Document 1 discloses a compressor having an electric motor. The compressor has a casing and an electric motor disposed inside the casing. The electric motor has a stator fixed to the inner peripheral surface of the casing. The casing and the stator are fixed by welding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-55576 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electric motor (rotating electric machine) such as that disclosed in Patent Document 1, the casing and the core are fixed together by applying compressive stress to the stator core in a point-like manner from the radially outer side to the radially inner side. However, when such compressive stress is applied to the stator, the portion of the stator to which the compressive stress is applied is deformed in the radial direction. As a result, there is a problem in that the gap between the stator and the rotor becomes uneven.

[0005] An object of the present disclosure is to suppress unevenness in the gap between the stator and the rotor. [Means for solving the problem]

[0006] The first aspect is a stator (31) having a core (32) and disposed inside the casing (11); a radial fixing portion (60) for fixing the casing (11) and the core (32) by applying a compressive stress to the core (32) in a point-like manner from the radially outer side to the radially inner side, The rigidity per unit axial length in the radial direction in the circumferential range and axial range of the portion of the core (32) to which the compressive stress is applied is higher than the rigidity per unit axial length in the radial direction of the entire core (32) in the circumferential range. It is a rotating electrical machine.

[0007] In the first aspect, the rigidity of the core (32) of the stator (31) at the portion to which compressive stress is applied is higher than the rigidity of the entire stator. Therefore, even if compressive stress is applied at points from the radially outer side to the radially inner side at the radial fixing portion (60), the portion to which compressive stress is applied can be prevented from being deformed in the radial direction. As a result, it is possible to prevent the gap between the stator (31) and the rotor from becoming uneven.

[0008] The second aspect is the first aspect, the core (32) includes a first core portion (C1) to which the compressive stress is applied in the circumferential range and a second core portion (C2) to which the compressive stress is not applied in the circumferential range, A first rigidity per unit axial length in the radial direction in the circumferential range of the first core portion (C1) where the compressive stress is applied is higher than a second rigidity per unit axial length in the radial direction of the second core portion in the circumferential range.

[0009] In the second aspect, the first core portion (C1) to which compressive stress is applied in a certain circumferential range has a higher rigidity (first rigidity) than the second core portion (C2) to which compressive stress is not applied in the same circumferential range, thereby preventing the first core portion (C1) from deforming in the radial direction at the portion to which compressive stress is applied.

[0010] The third aspect is the second aspect, the first core portion (C1) and the second core portion (C2) are formed by a plurality of electromagnetic steel plates (M) laminated in the axial direction, In the core (32), the method of fixing the plurality of electromagnetic steel plates (M) of the first core portion (C1) is different from the method of fixing the plurality of electromagnetic steel plates (M) of the second core portion (C2) so that the first rigidity is higher than the second rigidity.

[0011] In the third aspect, the first rigidity is made higher than the second rigidity by differentiating the method of fixing the plurality of electromagnetic steel plates (M) of the first core portion (C1) from the method of fixing the plurality of electromagnetic steel plates (M) of the second core portion (C2).

[0012] In a fourth aspect, in the third aspect, the stator (31) has, in the circumferential range, crimped portions (55) or welded portions that fix the plurality of electromagnetic steel plates (M) of the first core portion (C1).

[0013] In a fourth aspect, the plurality of electromagnetic steel plates (M) of the first core portion (C1) are fixed in the circumferential range by crimped portions (55) or welded portions, thereby increasing the first rigidity.

[0014] A fifth aspect is the third or fourth aspect, wherein the first core portion (C1) has at least one axial fixing portion (50) that fixes a plurality of electromagnetic steel plates (M), The circumferential angle between the axial fixed portion (50) and the radial fixed portion (60) closest to the axial fixed portion (50) is smaller than half the circumferential angle between the radial fixed portion (60) and the radial fixed portion (60) closest to the radial fixed portion (60).

[0015] In the fifth mode, the axially fixed portion (50) approaches the radially fixed portion (60). In the first core portion, the rigidity in the vicinity of the axially fixed portion (50) is increased, and therefore the rigidity of the portion to which compressive stress is applied corresponding to the radially fixed portion (60) can be improved.

[0016] The sixth aspect is the second aspect, the first core portion (C1) and the second core portion (C2) are formed by a plurality of electromagnetic steel plates (M) laminated in the axial direction, The thickness of the electromagnetic steel sheet (M) of the first core portion (C1) is greater than the thickness of the electromagnetic steel sheet (M) of the second core portion (C2).

[0017] In the sixth aspect, the thickness of the electromagnetic steel sheet (M) of the first core portion (C1) is made larger than the thickness of the electromagnetic steel sheet (M) of the second core portion (C2), so that the first rigidity is higher than the second rigidity.

[0018] The seventh aspect is the second aspect, In the core (32), the material of the first core portion (C1) is different from the material of the second core portion (C2) so that the first rigidity is higher than the second rigidity.

[0019] In the seventh aspect, the first core portion (C1) and the second core portion (C2) are made of different materials, so that the first rigidity is higher than the second rigidity.

[0020] An eighth aspect is a compressor including the rotating electric machine according to any one of the first to seventh aspects.

[0021] A ninth aspect is a refrigeration device including the compressor of the eighth aspect. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram of a refrigeration device according to an embodiment. [Figure 2] FIG. 2 is a longitudinal cross-sectional view corresponding to a cross section parallel to the axial direction of the compressor according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view corresponding to a cross section perpendicular to the axial direction of the electric motor. [Figure 4] FIG. 4 is a longitudinal cross-sectional view corresponding to a cross section parallel to the axial direction of the compressor of the electric motor. [Figure 5] FIG. 5 is a cross-sectional view of the first core portion, corresponding to a cross section perpendicular to the axial direction of the electric motor. [Figure 6] FIG. 6 is a cross-sectional view of the second core portion, corresponding to a cross section perpendicular to the axial direction of the electric motor. [Figure 7] FIG. 7 is a table showing the increase in rigidity and iron loss for each type of axial fixing portion. [Figure 8] Figure 8 is a structural diagram in which a longitudinal cross-sectional view corresponding to a cross section parallel to the axial direction in the compressor of the stator core of variant example 3 is added to a cross-sectional view corresponding to a cross section perpendicular to the axial direction in the electric motor of the first core portion and the second core portion. [Figure 9] Figure 9 is a structural diagram in which a longitudinal cross-sectional view corresponding to a cross section parallel to the axial direction in the compressor of the stator core of variant example 4 is added to a cross-sectional view corresponding to a cross section perpendicular to the axial direction in the electric motor of the first core portion and the second core portion. [Figure 10] Figure 10 is a structural diagram in which a longitudinal cross-sectional view corresponding to a cross section parallel to the axial direction in the compressor of the stator core of variant example 5 is added to a cross-sectional view corresponding to a cross section perpendicular to the axial direction in the electric motor of the first core portion and the second core portion. [Figure 11] Figure 11 is a structural diagram of another embodiment of variant example 5, in which a vertical cross-sectional view corresponding to a cross section parallel to the axial direction of the stator core compressor is added to a horizontal cross-sectional view corresponding to a cross section perpendicular to the axial direction of the first core portion and the second core portion of the electric motor. [Figure 12] FIG. 12 is a longitudinal cross-sectional view of a stator core of the sixth modification, which corresponds to a cross-section parallel to the axial direction of the compressor. [Figure 13] FIG. 13 is a longitudinal cross-sectional view of a stator core according to the seventh modification, which corresponds to a cross-section parallel to the axial direction of the compressor. [Figure 14] FIG. 14 is an enlarged cross-sectional view of a main part of the first core portion of the ninth modification, the cross-section being perpendicular to the axial direction of the electric motor. [Figure 15] FIG. 15 is an enlarged cross-sectional view of a main part of the second core portion of the ninth modified example, the cross-section being perpendicular to the axial direction of the electric motor. [Figure 16]FIG. 16 is a longitudinal cross-sectional view of a stator core of Modification 10, which corresponds to a cross section parallel to the axial direction of the compressor, and illustrates through holes formed during arc welding. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical concept of the present disclosure. Since the drawings are intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding.

[0024] The compressor (10) of the present disclosure is provided in a refrigeration system (1). (1) Overview of the refrigeration system The refrigeration system (1) shown in Fig. 1 includes a compressor (10) according to the present disclosure. The refrigeration system (1) has a refrigerant circuit (R) filled with a refrigerant. The refrigerant circuit (R) includes a compressor (10), a radiator (2), a pressure reduction mechanism (3), and an evaporator (4). The pressure reduction mechanism (3) is an expansion valve. The refrigerant circuit (R) performs a vapor compression refrigeration cycle.

[0025] In the refrigeration cycle, the refrigerant compressed by the compressor (10) dissipates heat to the air in the radiator (2). The refrigerant that has dissipated heat is reduced in pressure by the pressure reducing mechanism (3) and evaporated in the evaporator (4). The evaporated refrigerant is drawn into the compressor (10).

[0026] The refrigeration system (1) is an air conditioner. The air conditioner may be a cooling-only unit, a heating-only unit, or an air conditioner that switches between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) that switches the refrigerant circulation direction. The refrigeration system (1) may be a water heater, a chiller unit, a cooling device that cools the air inside a storage unit, or the like. The cooling device cools the air inside a refrigerator, a freezer, a container, or the like. The expansion mechanism is composed of an electronic expansion valve, a thermostatic expansion valve, an expander, or a capillary tube. (2) Compressor As shown in Fig. 2, the compressor (10) includes a casing (11), an electric motor (30), a drive shaft (20), and a compression mechanism (22). The compressor (10) is a rotary compressor. Strictly speaking, the compressor (10) is a oscillating piston compressor. The compressor (10) may be a scroll, screw, or turbo compressor. (2-1) Casing The casing (11) accommodates the electric motor (30), the drive shaft (20), and the compression mechanism (22). The casing (11) is a hermetically sealed container. The interior of the casing (11) is filled with high-pressure refrigerant discharged from the compression mechanism (22).

[0027] The casing (11) is made of a metal material. The casing (11) has a body (12), a bottom (13), and a top (14). The body (12) is a cylindrical metal member. An opening is formed at each end of the body (12) in the axial direction. In this example, the axial direction of the body (12) corresponds to the vertical direction. The bottom (13) closes the opening on the lower side of the body (12). The top (14) closes the opening on the upper side of the body (12). (2-2) Electric motor The electric motor (30) shown in Figures 2 and 3 is an example of a rotating electric machine. The electric motor (30) is disposed above the compression mechanism (22). The operation frequency of the electric motor (30) is controlled by an inverter device. In other words, the compressor (10) is an inverter type whose operation frequency is variable.

[0028] The electric motor (30) has a stator (31) and a rotor (40). The stator (31) is supported by the body (12) of the casing (11). The stator (31) has a stator core (32) and a coil (33) wound around the stator core (32). The stator core (32) constitutes a core of the present disclosure. The stator core (32) is formed by stacking electromagnetic steel sheets (M) in the axial direction. As shown in FIG. 3 , the stator core (32) has an annular yoke (34) and a plurality of (nine in this example) teeth (35) extending radially inward from the inner circumferential surface of the yoke (34). Details of the stator core (32) and its fixing structure will be described later.

[0029] A plurality of (nine in this example) core cuts 36 are formed on the outer peripheral surface of the yoke 34. The core cuts 36 are grooves extending in the axial direction of the stator core 32. Each core cut 36 is formed on the opposite side of the yoke 34 from the teeth 35.

[0030] The rotor (40) is disposed inside the stator core (32). The drive shaft (20) is fixed to the central axis of the rotor (40). A plurality of permanent magnets (not shown) are embedded inside the rotor (40).

[0031] An annular gap (G) is formed between the teeth (35) of the stator (31) and the rotor (40) in cross section. (2-3) Drive shaft The drive shaft (20) extends vertically along the axis of the casing (11). The drive shaft (20) is driven to rotate by an electric motor (30). The drive shaft (20) is rotatably supported by bearings (21). (2-4) Compression mechanism The compression mechanism (22) has a cylinder (23) and a piston (24) provided inside the cylinder (23). A cylinder chamber (25) is formed between the inner peripheral surface of the cylinder (23) and the outer peripheral surface of the piston (24). In the cylinder chamber (25), the fluid is compressed by the piston (24) driven by the drive shaft (20). (2-5) Intake pipe and discharge pipe The compressor (10) has a suction pipe (26) and a discharge pipe (27). The suction pipe (26) passes radially through the body (12) and communicates with the cylinder chamber (25). Low-pressure refrigerant in the refrigerant circuit (R) is drawn into the cylinder chamber (25) through the suction pipe (26). The discharge pipe (27) passes axially through the top (14) and communicates with the interior space of the casing (11). The refrigerant compressed by the compression mechanism (22) flows through the core cut (36) and the gap (G) of the electric motor (30), and is then sent to the refrigerant circuit (R) through the discharge pipe (27). (3) Details of the stator core (3-1) Configuration of the core part of the stator core The stator core (32) will be described in detail with reference to Figs. 2 to 6. In the following description, the terms "axial direction," "circumferential direction," and "radial direction" refer to the axial direction, circumferential direction, and radial direction of the stator (31), respectively, unless otherwise specified. In this example, the axial direction of the stator (31) corresponds to the axial direction of the drive shaft (20) as shown in Fig. 2.

[0032] As shown in FIG. 4, in the stator core 32, a plurality of electromagnetic steel sheets M are stacked from one end to the other in the axial direction. In the stator core 32 of this example, all of the electromagnetic steel sheets M have the same structure. Strictly speaking, all of the electromagnetic steel sheets M have the same shape, thickness, and material. All of the electromagnetic steel sheets M are arranged so that their entirety completely overlaps in the axial direction.

[0033] The stator core (32) has multiple core portions. In this example, the stator core (32) is composed of core portion A (CA), core portion B (CB), and core portion C (CC). Each of the core portions (CA, CB, CC) has multiple electromagnetic steel sheets (M) stacked in the axial direction. The electromagnetic steel sheets (M) contain a predetermined content (wt%) of Si (silicon). Core portion A (CA) is located at the top of the stator core (32), and core portion C (CC) is located at the bottom of the stator core (32). Core portion B (CB) is disposed between core portion A (CA) and core portion B (CB). The axial length of core portion B (CB) is shorter than the axial lengths of core portion A (CA) and core portion C (CC).

[0034] The stator core 32 has axial fixing portions 50. The axial fixing portions 50 fix the axially adjacent electromagnetic steel sheets M. As shown in FIG. 5, the axial fixing portions 50 are provided in the core portion B (CB). In the core portion B (CB) of this example, for all of the electromagnetic steel sheets M, the axially adjacent electromagnetic steel sheets M are fixed via the axial fixing portions 50.

[0035] The axial fixing portions 50 are provided on the yoke 34 of the core portion B (CB). In this example, three axial fixing portions 50 are arranged at equal angular intervals (equal pitch) in the circumferential direction. In other words, the angles (120° in this example) between adjacent axial fixing portions 50 are all equal. The axial fixing portions 50 are arranged in a region of the yoke 34 radially outward from the teeth 35. In this embodiment, the axial fixing portions 50 are crimped portions 55. The crimped portions 55 are formed by processing (so-called crimping) that plastically deforms an electromagnetic steel sheet M in the axial direction. In this example, the crimped portions 55 are formed in a rectangular shape when viewed from the axial direction. One long side of the crimped portion 55 faces radially outward, and the other long side faces radially inward. The bottom surface of the crimped portion (55) has an inclined surface that slopes from both short sides toward the center of the long side. Specifically, the cross-sectional shape of the bottom surface of the crimped portion (55) is V-shaped. The cross-sectional shape of the bottom surface of the crimped portion (55) may be U-shaped or trapezoidal. The bottom surface of the crimped portion (55) may also be flat.

[0036] As shown in Fig. 6, core portion A (CA) and core portion C (CC) are not provided with axial fixing portions 50. Therefore, adjacent electromagnetic steel sheets M of core portion A (CA) are not fixed, and adjacent electromagnetic steel sheets M of core portion C (CC) are also not fixed. Note that by winding the coil 33 around the teeth 35 of the stator core 32, core portion A (CA) and core portion C (CC) are substantially integrated with core portion B (CB).

[0037] In this embodiment, core portion B (CB) constitutes a first core portion (C1) of the present disclosure, and core portion A (CA) and core portion C (CC) constitute a second core portion (C2) of the present disclosure. In this embodiment, the first core portion (C1) is provided with an axial fixing portion (50), but the second core portion (C2) is not provided with an axial fixing portion (50). (3-2) Stator core fixing structure The stator (31) has radial fixing portions (60) that fix the stator core (32) to the casing (11). The radial fixing portions (60) fix the casing (11) to the outer circumferential surface of the stator core (32). Specifically, the radial fixing portions (60) fix the casing (11) to the stator core (32) by applying compressive stress in a point pattern from the radially outer side to the radially inner side of the stator core (32). The radial fixing portions (60) of this embodiment fix the casing (11) to the stator core (32) by arc welding (strictly speaking, plug welding).

[0038] 4 and 5, in this embodiment, the casing (11) and the core portion B (CB) are fixed together by the radial fixing portion (60). As shown in Fig. 6, the casing (11) and the core portion A (CA) are not fixed together by the radial fixing portion (60), and the casing (11) and the core portion C (CC) are not fixed together by the radial fixing portion (60).

[0039] As shown in FIG. 5, the core portion B (CB) is fixed by three radial fixing portions (60). The three radial fixing portions (60) are composed of a first radial fixing portion (61), a second radial fixing portion (62), and a third radial fixing portion (63). In this example, these radial fixing portions (60) are arranged at equal angular intervals (equal pitch) in the circumferential direction. In other words, the angles formed by adjacent radial fixing portions (60) are all equal (120° in this example). The radial fixing portions (60) in this example fix the portions of the yoke (34) between adjacent core cuts (36) to the casing (11).

[0040] In core portion B (CB), the radially fixed portion (60) is disposed closer to the axially fixed portion (50). Specifically, in core portion B (CB), the circumferential angle (angle θ1 in FIG. 5) between the axially fixed portion (50) and the radially fixed portion (60) closest to this axially fixed portion (50) is smaller than half the circumferential angle (angle θ2 in FIG. 5) between the radially fixed portion (60) and the radially fixed portion (60) closest to the radially fixed portion (60). (3-3) Stator fixing method The method for fixing the casing (11) and the stator (31) by arc welding includes the following steps.

[0041] First step: A through hole is drilled in the body (12) of the casing (11).

[0042] Second step: An automatic welding machine presses an electrode through the through hole against the outer circumferential surface of the stator core 32. At this time, compressive stress is applied to the stator core 32 in a point pattern from the radially outer side to the radially inner side.

[0043] Third step: The automatic welding machine moves the electrode radially outward so as to ensure a predetermined gap between the electrode and the stator core (32).

[0044] Fourth step: The automatic welding machine generates an arc discharge between the electrode and the stator core 32. This welds the casing 11 to the stator core 32. The through-hole is closed by the welded portion. (4) Issues caused by radial fixing parts As described above, in this embodiment, when the casing (11) and the stator core (32) are fixed together, point-like compressive stress is applied to the stator core (more precisely, to the core portion B (CB)) from the radially outer side to the radially inner side. This may cause the stator core (32) to deform radially inward. In this case, the gap (G) between the stator core (32) and the rotor (40) becomes non-uniform in the axial and radial directions. When the gap (G) becomes non-uniform, the magnetic resistance and the electromagnetic force between the stator core (32) and the rotor (40) become non-uniform, resulting in noise during operation of the electric motor (30).

[0045] One possible method for suppressing radially inward deformation of the stator core 32 is to fix multiple electromagnetic steel plates M throughout the entire stator core 32 with axial fixing portions 50, such as crimped portions. This improves the rigidity of the stator core 32. However, this method increases iron loss in the stator core 32 due to the multiple axial fixing portions 50 provided across both axial ends of the stator core 32. Specifically, when the formation of the crimped portions 55 causes plastic deformation around the crimped portions 55, residual stress deteriorates the magnetic properties and increases hysteresis loss. Fastening the crimped portions 55 increases eddy current loss, which increases iron loss. As a result, the efficiency of the electric motor 30 decreases. (5) Stator core rigidity In order to solve the above problems, the stator core (32) of this embodiment is configured so that its rigidity satisfies the following relations 1 and 2.

[0046] Relationship 1: The rigidity per unit axial length in the radial direction in the circumferential and axial ranges of the portion of the stator core (32) to which compressive stress is applied due to the radial fixing portion (60) is higher than the rigidity per unit axial length in the radial direction of the entire stator (31) in this circumferential range.

[0047] Relationship 2: The first rigidity per unit axial length in the radial direction in the circumferential range of the first core portion (C1) (core portion B (CB)) where compressive stress is applied is higher than the second rigidity per unit axial length in the radial direction of the second core portion (C2) (core portion A (CA) and core portion C (CC)) in this circumferential range.

[0048] Relationship 3: The total iron loss of the first core portion (C1) is greater than the total iron loss of the second core portion (C2).

[0049] These relationships will now be explained in detail.

[0050] As shown in Fig. 5, the circumferential range corresponding to the first radial fixed portion (61) is designated Rc1, the circumferential range corresponding to the second radial fixed portion (62) is designated Rc2, and the circumferential range corresponding to the third radial fixed portion (63) is designated Rc3. Fig. 4 illustrates the axial range Ra1 corresponding to the first radial fixed portion (61).

[0051] Relations 1 and 2 will be described with reference to the circumferential range Rc1 of the first radial fixed portion 61. Due to the provision of the first radial fixed portion 61, compressive stress is applied to the core portion B (CB) in the circumferential range Rc1 and the axial range Ra1. Meanwhile, as described above, in the core portion B (CB), the multiple electromagnetic steel sheets M are fixed by the axial fixed portion 50 (strictly speaking, the crimped portion 55). Therefore, in the core portion B (CB), by providing the crimped portion 55, the first rigidity (unit: kN / mm) per unit axial length in the radial direction increases in the circumferential range Rc1 of the portion to which compressive stress is applied by the first radial fixed portion 61.

[0052] Additionally, in the core part B (CB), the axial fixed part (50) is disposed closer to the first radial fixed part (61). Strictly speaking, the circumferential angle (angle θ1 in FIG. 5) between the axial fixed part (50) and the first radial fixed part (61) closest to the axial fixed part (50) is smaller than half the circumferential angle (angle θ2 in FIG. 5) between the first radial fixed part (61) and the radial fixed part (60) closest to the first radial fixed part (61). Therefore, in the core part B (CB), the first rigidity is increased by disposing the axial fixed part (50) closer to the first radial fixed part (61).

[0053] In contrast, the core portion A (CA) and the core portion C (CC) are not provided with the axial fixing portion 50. Therefore, in the core portion A (CA) and the core portion C (CC), the second rigidity per unit axial length in the radial direction in the circumferential range Rc1 does not increase.

[0054] As a result, in the stator core (32), the first rigidity per unit axial length in the radial direction in the circumferential range Rc1 of the portion of the core portion B (CB) to which compressive stress is applied is higher than the second rigidity per unit axial length in the radial direction of the core portion A (CA) and the core portion C (CC) in this circumferential range Rc1. Therefore, Relation 2 is established.

[0055] In addition, in the stator core (32), the rigidity per unit axial length in the radial direction in the circumferential range Rc1 and the axial range Ra1 of the portion to which compressive stress is applied due to the radial fixed portion (60) is higher than the rigidity per unit axial length in the radial direction of the entire stator (31) in the circumferential range Rc1. Thus, Relation 1 is established.

[0056] Similarly, when the circumferential range Rc2 of the second radial fixed portion (62) is used as the reference, and when the circumferential range Rc3 of the third radial fixed portion (63) is used as the reference, the relations 1 and 2 hold true.

[0057] In the stator core (32), the core portion B (CB) which is the first core portion (C1) is provided with an axially fixed portion (50), while the core portion A (CA) and the core portion C (CC) which are the second core portion (C2) are not provided with an axially fixed portion (50). This establishes Relation 3. (6) Effects of the embodiment (6-1) In the stator core (32), satisfying the above-mentioned relationship 1 can suppress deformation of the portion to which compressive stress is applied by the radial fixed portion (60). In addition, satisfying the above-mentioned relationship 2 can suppress deformation of the portion to which compressive stress is applied by the radial fixed portion (60). This can suppress unevenness of the gap (G) in the axial and radial directions. As a result, noise generation during operation of the electric motor (30) can be suppressed. (6-2) In the stator core (32), the second core portion (C2), i.e., core portion A (CA) and core portion C (CC), are not provided with the axially fixed portion (50). This prevents an increase in iron loss in core portion A (CA) and core portion C (CC) that would be caused by providing the axially fixed portion (50). As a result, a decrease in the efficiency of the electric motor (30) can be prevented. In addition, an increase in manufacturing time and cost that would be caused by providing the axially fixed portion (50) can be prevented. (6-3) The axial fixing portion 50 is a crimped portion 55. The crimped portion 55 has a relatively high joining strength between adjacent electromagnetic steel sheets M, and therefore can reliably increase the first rigidity of the core portion B (CB), which is the first core portion C1. (6-4) In the core portion B (CB), the circumferential angle between the axial fixed portion (50) and the radial fixed portion (60) closest to the axial fixed portion (50) (for example, angle θ1 in FIG. 5) is smaller than half the circumferential angle between the radial fixed portion (60) and the radial fixed portion (60) closest to the radial fixed portion (60) (angle θ2 in FIG. 5). This increases the rigidity of the stator core (32) near the radial fixed portion (60), thereby reliably increasing the first rigidity. (7) Variations A modified example of the embodiment will be described. In the following description, differences from the above-described embodiment will be mainly described. (7-1) Variation 1 In the embodiment, the axial fixing portion 50 of the first core portion C1 is formed by the crimped portion 55. However, the axial fixing portion 50 of the first core portion C1 may have a configuration other than the crimped portion 55.

[0058] Specifically, the axial fixing portion 50 may be a welded portion. The welded portion is provided on the outer peripheral surface of the stator core 32 and fixes adjacent electromagnetic steel sheets M. As shown in FIG. 7, the radial rigidity of the stator core 32 obtained by the welded portion is higher than that of the crimped portion 55. Therefore, by using the welded portion as the axial fixing portion of the first core portion C1, the first rigidity of the first core portion C1 can be further increased compared to the embodiment.

[0059] The axial fixing portion (50) may be formed of a varnish portion or an adhesive portion. The varnish portion fixes adjacent electromagnetic steel sheets (M) with varnish, which is a paint. The adhesive portion fixes adjacent electromagnetic steel sheets (M) with adhesive. The varnish portion or adhesive portion is formed between adjacent electromagnetic steel sheets. The radial rigidity of the stator core (32) obtained by the varnish portion or adhesive portion is lower than that of the crimped portion (55). However, the varnish portion or adhesive portion does not increase iron loss like the crimped portion or welded portion, so it is possible to increase the first rigidity while suppressing a decrease in motor efficiency. Note that if the axial fixing portion (50) is a crimped portion (55) or a welded portion, a short circuit occurs between adjacent electromagnetic steel sheets, which increases eddy current loss and tends to increase iron loss. (7-2) Variation 2 The above-described relations 1, 2, and 3 may be satisfied by differentiating the fixing methods of the plurality of electromagnetic steel sheets (M) between the first core portion (C1) and the second core portion (C2). In other words, in the stator core (32), the fixing method of the plurality of electromagnetic steel sheets (M) of the first core portion (C1) is different from the fixing method of the plurality of electromagnetic steel sheets (M) of the second core portion (C2) so that the first rigidity is higher than the second rigidity.

[0060] Specifically, the first core portion C1 (core portion B (CB)) of the above-described embodiment is provided with a crimped portion 55 as an axial fixing portion 50 (hereinafter referred to as a first axial fixing portion). The second core portion C2 (core portion A (CA) and core portion C (CC)) is provided with a varnish portion as an axial fixing portion 50 (hereinafter referred to as a second axial fixing portion). As shown in FIG. 7, the crimped portion 55 provides a greater effect of improving rigidity than the varnish portion. Therefore, by adopting different fixing methods for the first core portion C1 and the second core portion C2, Relationships 1, 2, and 3 can be satisfied.

[0061] In this example, the first rigidity of the first core portion C1 can be reliably increased by the crimped portion 55. The second core portion C2 is provided with a varnished portion, which can suppress an increase in iron loss and, in turn, a decrease in motor efficiency.

[0062] As long as Relationship 1, Relationship 2, and Relationship 3 can be satisfied, there are no limitations on the positions and numbers of the first axially fixed portion and the second axially fixed portion.

[0063] The first axial fixing portion may be a crimped portion (55), and the second axial fixing portion may be an adhesive portion. The first axial fixing portion may be a welded portion, and the second axial fixing portion may be a varnished portion or an adhesive portion. If the number of crimped portions (55) of the first axial fixing portion is N, the number of crimped portions (55) of the second axial fixing portion may be less than N. If the number of welded portions of the first axial fixing portion is N, the number of welded portions of the second axial fixing portion may be less than N. (7-3) Variation 3 The stator core (32) of Modification 3 shown in Fig. 8 has a core part D (CD), a core part E (CE), and a core part F (CF). In the stator core (32), the core part D (CD), the core part E (CE), and the core part F (CF) are arranged in this order from the upper end to the lower end.

[0064] In this example, a radial fixing portion (60) is provided for each core portion (CD, CE, CF). In this example, one radial fixing portion (60) is provided for each core portion (CD, CE, CF). The radial fixing portions (60) are offset in the circumferential direction between core portion D (CD), core portion E (CE), and core portion F (CF). Specifically, the radial fixing portions (60) of core portion D (CD), core portion E (CE), and core portion F (CF) are arranged at equal angular intervals (120°) in the circumferential direction.

[0065] Each core portion (CD, CE, CF) is provided with a crimped portion (55) as an axially fixed portion (50). In this example, a crimped portion (55) is provided on each circumferential side of the radially fixed portion (60). In this example, as in the embodiment, the radially fixed portion (60) is disposed closer to the axially fixed portion (50) so that θ1 is smaller than ½ of θ2. In Modification 3, the relative positions of the radially fixed portion (60) and the axially fixed portion (50) are determined so that Relationship 1 and Relationship 2 are satisfied.

[0066] For example, the circumferential range Rc4 of the radially fixed portion (60) of the core portion D (CD) is taken as a reference. In this case, the core portion D (CD) becomes the first core portion (C1), and the core portions E (CE) and F (CF) become the second core portions (C2). In the core portion D (CD), compressive stress is applied in this circumferential range Rc4. In the core portion D (CD), a crimped portion (55) is provided closer to the circumferential range Rc4. Therefore, in the core portion D (CD), the first rigidity in the circumferential range Rc4 is large. In contrast, in the core portion E (CE) and the core portion F (CF), the crimped portion (55) is not disposed closer to the circumferential range Rc4. Therefore, in the core portion E (CE) and the core portion F (CF), the second rigidity in the circumferential range Rc4 is small. Therefore, in this example, when the circumferential range Rc4 is taken as a reference, the relations 1 and 2 hold. The same is true when the circumferential range corresponding to the radial fixed portion (60) of the core portion E (CE) or the circumferential range corresponding to the radial fixed portion (60) of the core portion F (CF) is used as the reference.

[0067] In this example, while providing the axial fixing portion (50) in all of the core portions (CD, CE, CF), it is possible to satisfy the relationship 1 and the relationship 2. In this example as well, the axial fixing portion (50) may have a configuration other than the crimped portion (55).

[0068] In addition, in this example, the radially fixed portions (60) of the core portions (CD, CE, CF) are offset by an equal angle in the circumferential direction, which increases the bonding strength between the stator core (32) and the casing (11) compared to when the radially fixed portions (60) are unevenly distributed. (7-4) Variation 4 The stator core (32) of Modification 4 shown in FIG. 9 is similar to Modification 3 in that it further includes core portions G (CG) and H (CH). Core portion G (CG) is disposed between core portion D (CD) and core portion E (CE), and core portion H (CH) is disposed between core portion E (CE) and core portion F (CF). Core portions G (CG) and H (CH) are not provided with radially fixed portions (60) or axially fixed portions (50). Therefore, core portions G (CG) and H (CH) have low radial rigidity, similar to core portions A (CA) and C (CC) of the embodiment.

[0069] When the circumferential range Rc4 of the core portion D (CD) is used as a reference, the core portion D (CD) becomes the first core portion (C1), and the other core portions (core portion E (CE), core portion F (CF), core portion G (CG), and core portion H (CH)) become the second core portions (C2). In this case, the first rigidity of the core portion D (CD) is higher than the second rigidity of the core portion E (CE), core portion F (CF), core portion G (CG), and core portion H (CH). Therefore, in this example, when the circumferential range Rc4 is used as a reference, the relations 1 and 2 hold. The same can be said when the circumferential range corresponding to the radially fixed portion (60) of the core portion E (CE) or the circumferential range corresponding to the radially fixed portion (60) of the core portion F (CF) is used as a reference.

[0070] In this example, since the axially fixed portions (50) are not provided on the core portion G (CG) and the core portion H (CH), it is possible to avoid an increase in iron loss of the stator core (32), as in the embodiment. Note that core portions without the radially fixed portions (60) and the axially fixed portions (50) may be disposed above the core portion D (CD) or below the core portion F (CF). (7-5) Variation 5 The stator core (32) of the fifth modification shown in FIG. 10 is different from the third modification in the positions and the number of the radial fixed portions (60) and the axial fixed portions (50).

[0071] In this example, each of the core portions D (CD), E (CE), and F (CF) is provided with three radially fixed portions (60) in the same manner as in the above embodiment. The radially fixed portions (60) are offset in the circumferential direction between the core portions D (CD), E (CE), and F (CF). Specifically, the radially fixed portions (60) are arranged at equal angular intervals (120°) in the circumferential direction in the core portions D (CD), E (CE), and F (CF). The stator core (32) as a whole has nine radially fixed portions (60) arranged at equal angular intervals (40°) in the circumferential direction. This increases the bonding strength between the stator core (32) and the casing (11).

[0072] In each core portion (CD, CE, CF), the two crimped portions (55) are disposed closer to the radially fixed portion (60), as in Modifications 3 and 4. In Modification 5, the relative positions of the radially fixed portion (60) and the axially fixed portion (50) are determined so that Relationship 1 and Relationship 2 are satisfied. Note that, in the stator core (32) of Modification 5, a core portion without a radially fixed portion (60) and an axially fixed portion (50) may be added, as in Modification 4. As shown in FIG. 11 , in the configuration of Modification 5, one of the axially fixed portions (50) on both sides of the radially fixed portion (60) may be omitted. (7-6) Variation 6 The stator core (32) of Modification 6 shown in Fig. 12 has a core portion A (CA), a core portion B (CB), and a core portion C (CC) as in the embodiment. The core portion B (CB) of Modification 6 is provided with a radial fixed portion (60). The core portion A (CA), the core portion B (CB), and the core portion C (CC) are not provided with an axial fixed portion (50).

[0073] On the other hand, in Modification 6, the thickness of the plurality of electromagnetic steel sheets (M) (first electromagnetic steel sheets (M1)) of core portion B (CB), which is the first core portion (C1), is greater than the thickness of the plurality of electromagnetic steel sheets (M) (second electromagnetic steel sheets (M2)) of core portion A (CA) and core portion B (CB), which are the second core portion (C2). As a result, the first rigidity of core portion B (CB) is greater than the second rigidity of core portion A (CA) and core portion C (CC), and Relationships 1 and 2 are established. (7-7) Variation 7 The stator core (32) of the seventh modification shown in FIG. 13 has a core portion A (CA), a core portion B (CB), and a core portion C (CC), similar to the embodiment. In this example, the core portion B (CB) is formed by stacking a plurality of electromagnetic steel plates (M), similar to the embodiment. The core portion A (CA) and the core portion C (CC) are formed by a block body (70) made of a soft magnetic material. The soft magnetic material is, for example, an amorphous metal. The core portion A (CA) and the core portion C (CC) may also be formed by stacking a plurality of plate-shaped soft magnetic materials.

[0074] In Modification 7, the first core portion (C1) or core portion B (CB) is made of a different material from the second core portion (C2) or core portion A (CA) or core portion C (CC) so as to satisfy Relationships 1 and 2. Specifically, the radial rigidity of the material of core portion B (CB) of the stator core (32) is higher than the radial rigidity of the material of core portion A (CA) or core portion B (CB). This allows Relationships 1 and 2 to be satisfied without providing axial fixing portions (50) on core portion A (CA) or core portion C (CC). (7-8) Variation 8 The stator core (32) of the eighth modification has a plurality of electromagnetic steel sheets (M) in each of the core portions A (CA), B (CB), and C (CC). These electromagnetic steel sheets (M) have the same shape.

[0075] On the other hand, in Modification 8, the material of the electromagnetic steel sheet (M) (first electromagnetic steel sheet (M1)) of core portion B (CB) is different from the material of the electromagnetic steel sheet (M) (second electromagnetic steel sheet (M2)) of core portion A (CA) and core portion C (CC). Specifically, the Si content of the first electromagnetic steel sheet (M1) is higher than the Si content of the second electromagnetic steel sheet (M2). This makes the radial rigidity of core portion B (CB) higher than the radial rigidity of the material of core portion A (CA) and core portion B (CB). As a result, Relations 1 and 2 can be established by making the shapes of the multiple core portions (CA, CB, CC) the same and without providing an axial fixing portion 50.

[0076] By increasing the Si content of the magnetic steel sheets (M) of the core portion B (CB), it is possible to reduce the deterioration of magnetic properties when the above-mentioned radial compressive stress is applied to the core portion B (CB). (7-9) Variation 9 In Modification 9, the shapes of the first core portion (C1) and the second core portion (C2) are different so as to satisfy Relationship 1 and Relationship 2. Specifically, the radial width D1 of the yoke (34) of the first core portion (core portion B (CB)) shown in FIG. 14 is greater than the radial width D2 of the yoke (34) of the second core portion (C2) (core portion A (CA) or core portion C (CC)) shown in FIG. 15. In the first core portion (C1), the first rigidity can be increased by increasing the width D1 of the yoke (34). This allows Relationship 1 and Relationship 2 to be established. (7-10) Variation 10 In the above-described embodiment, as shown in Fig. 16, a through hole 80 is formed in the body of the casing 11 during arc welding. The axial length L1 of the first core portion C1 may be greater than the axial length L2 of the stator core 32 at the through hole 80. In this case, it is preferable that one axial end of the first core portion C1 is located axially outward from the through hole 80, and it is even more preferable that both axial ends of the first core portion C1 are located axially from the through hole 80. This allows the first core portion C1 to obtain sufficient rigidity for a portion to which compressive stress is applied. (8) Other embodiments The radial fixing portion 60 in the embodiment fixes the casing 11 and the stator core 32 by arc welding (plug welding). However, the radial fixing portion 60 may be a fixing portion that uses a method of applying a compressive stress in a point pattern from the radially outer side to the radially inner side of the stator core 32, and may be a fixing portion that uses other methods such as welding, pressure welding, or bolt fastening.

[0077] If the axial fixing portions 50 are crimped portions 55, they may be arranged in the radially outer regions of all the teeth 35. In this case, for example, nine crimped portions 55 may be provided corresponding to nine teeth 35. If the axial fixing portions 50 are welded portions, welded portions may be provided corresponding to all the core cuts 36.

[0078] An axial fixing portion (third axial fixing portion) for fixing the first core portion (C1) and the second core portion (C2) in the axial direction may be provided.

[0079] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and details are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate.

[0080] The terms "first," "second," "third," etc. mentioned above are used to distinguish the terms to which these terms are attached, and do not limit the number or order of the terms. [Industrial Applicability]

[0081] As described above, the present disclosure is useful for compressors. [Explanation of symbols]

[0082] C1 First Core C2 Second Core 11 Casing 31 Stator 32 Stator core (core) 50 Axial fixed part 55 Crimping part 60 Radial fixed part

Claims

1. a stator (31) having a core (32) and disposed inside the casing (11); a radial fixing portion (60) that fixes the casing (11) and the core (32) by applying a compressive stress to the core (32) in a point-like manner from the radially outer side to the radially inner side, The core (32) has a plurality of core portions (C1, C2), The plurality of core portions (C1, C2) have the same outer edge shape and size, and are arranged so that the entire core portions completely overlap in the axial direction, the rigidity per unit axial length in the radial direction in the circumferential range and the axial range of the portion of the core (32) to which the compressive stress is applied is higher than the rigidity per unit axial length in the radial direction of the entire core (32) in the circumferential range, the plurality of core portions (C1, C2) include a first core portion (C1) to which the compressive stress is applied in the circumferential range and a second core portion (C2) to which the compressive stress is not applied in the circumferential range, A first rigidity per unit axial length in the radial direction in a circumferential range of a portion of the first core portion (C1) to which the compressive stress is applied is higher than a second rigidity per unit axial length in the radial direction of the second core portion (C2) in the circumferential range. Rotating electrical machines.

2. the first core portion (C1) and the second core portion (C2) are formed by a plurality of electromagnetic steel plates (M) laminated in the axial direction, In the core (32), a method for fixing the plurality of electromagnetic steel sheets (M) of the first core portion (C1) is different from a method for fixing the plurality of electromagnetic steel sheets (M) of the second core portion (C2) so that the first rigidity is higher than the second rigidity.

2. A rotating electrical machine according to claim 1.

3. The stator (31) has, in the circumferential range, crimped portions (55) or welded portions that fix the plurality of electromagnetic steel plates (M) of the first core portion (C1).

3. A rotating electrical machine according to claim 2.

4. the first core portion (C1) has at least one axial fixing portion (50) for fixing a plurality of electromagnetic steel plates (M), The angle in the circumferential direction between the axial fixed portion (50) and the radial fixed portion (60) closest to the axial fixed portion (50) is smaller than half the angle in the circumferential direction between the radial fixed portion (60) and the radial fixed portion (60) closest to the radial fixed portion (60). A rotating electrical machine according to claim 2 or 3.

5. the first core portion (C1) and the second core portion (C2) are formed by a plurality of electromagnetic steel plates (M) laminated in the axial direction, The thickness of the electromagnetic steel sheet (M) of the first core portion (C1) is greater than the thickness of the electromagnetic steel sheet (M) of the second core portion (C2).

2. A rotating electrical machine according to claim 1.

6. In the core (32), the material of the first core portion (C1) is different from the material of the second core portion (C2) so that the first rigidity is higher than the second rigidity.

2. A rotating electrical machine according to claim 1.

7. A compressor comprising a rotary electric machine according to any one of claims 1 to 6.

8. A refrigeration system comprising the compressor according to claim 7.

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