Motor, compressor, and refrigeration apparatus

Abstract

To effectively support a coil while suppressing deterioration of the coil's heat dissipation properties.SOLUTION: A motor includes a stator core (21a) including a cylindrical back yoke (21a1) and teeth (21a2) projecting radially inward from the back yoke (21a1) of the rotary shaft (70), a coil (21d) wound around the teeth (21a2), and a cover member (300) covering a portion of the coil (21d). The coil (21d) includes a covered portion (21d1) covered by the cover member (300) and an exposed portion (21d2) not covered by the cover member (300). The covered portion (21d1) is located radially inward of the coil (21d), and the exposed portion (21d2) is located radially outward of the coil (21d).SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a rotating electric machine. The rotating electric machine described in Patent Document 1 includes a stator core, a coil wound around the stator core, and a resin molded portion that covers at least the coil portion. The resin molded portion has a molded resin layer formed with a concave-convex shape that follows the outer shape of the coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-050048 Summary of the Invention [Problem to be solved by the invention]

[0004] However, because the coil is entirely covered with a resin molded portion, the heat dissipation of the coil is impaired, and there is a possibility that the required output of the rotating electric machine cannot be obtained due to thermal insulation. Furthermore, if the coil is not covered with a resin molded portion in order to ensure heat dissipation of the coil, the coil may not be supported effectively and may bend.

[0005] An object of the present disclosure is to provide a motor, a compressor, and a refrigeration device that can effectively support a coil while preventing deterioration of the heat dissipation performance of the coil. [Means for solving the problem]

[0006] The motor of the first aspect rotates a rotating shaft 70. The motor of the first aspect includes a stator core 21a including a cylindrical back yoke 21a1 and teeth 21a2 protruding from the back yoke 21a1 radially inward of the rotating shaft 70, a coil 21d wound around the teeth 21a2, and a cover member 300 covering a portion of the coil 21d, the coil 21d including a covered portion 21d1 covered by the cover member 300 and an exposed portion 21d2 not covered by the cover member 300, the covered portion 21d1 being located radially inward of the coil 21d, and the exposed portion 21d2 being located radially outward of the coil 21d.

[0007] In the first aspect, the cover member (300) supports the coil (21d), while the exposed portion (21d2) ensures heat dissipation from the coil (21d).

[0008] In the second embodiment, in the first embodiment, the cover member (300) is coated with or impregnated with varnish.

[0009] In the second embodiment, the coil (21d) can be fixed to the cover member (300) by varnish.

[0010] In a third aspect, in the first or second aspect, the cover member (300) has permeability to varnish.

[0011] In the third embodiment, the cover member (300) can be effectively impregnated with varnish.

[0012] A fourth aspect is any one of the first to third aspects, wherein the cover member (300) contains meta-aramid fibers.

[0013] In a fourth embodiment, a cover member (300) made of meta-aramid fiber can be placed on the coil (21d).

[0014] A fifth aspect is any one of the first to fourth aspects, wherein the cover member (300) has a ring shape.

[0015] In the fifth embodiment, the cover member (300) can be easily placed on the coil (21d).

[0016] A compressor according to a sixth aspect includes the motor according to any one of the first to fifth aspects.

[0017] A refrigeration device according to a seventh aspect includes the compressor according to the sixth aspect. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a piping diagram of a refrigeration device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the compressor according to the embodiment. [Figure 3] FIG. 3 is a perspective view of the stator. [Figure 4] FIG. 4 is a view of the stator as viewed in the axial direction. [Figure 5] FIG. 5 is a cross-sectional view showing the positional relationship between the covered portion and the exposed portion of the coil. DETAILED DESCRIPTION OF THE INVENTION

[0019] 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 each drawing is intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding. In each embodiment, modified example, and drawing, the same or equivalent parts are designated by the same reference symbols, and detailed descriptions and descriptions of the accompanying effects will not be repeated.

[0020] - Refrigeration equipment - As shown in FIG. 1, a compressor (1) is applied to a refrigeration system (100). The compressor (1) is, for example, a rotary compressor. The refrigeration system (100) is, for example, an air conditioner that conditions the air inside a room. The refrigeration system (100) has an outdoor unit (7) disposed outside the room and an indoor unit (8) disposed inside the room. The outdoor unit (7) includes a compressor (1), an accumulator (2), a four-way switching valve (3), an outdoor heat exchanger (4), and an expansion valve (5). The indoor unit (8) includes an indoor heat exchanger (6).

[0021] The refrigeration system (100) includes a refrigerant circuit (9). The refrigerant circuit (9) is connected to a compressor (1), a four-way switching valve (3), an outdoor heat exchanger (4), an expansion valve (5), and an indoor heat exchanger (6). A refrigeration cycle is performed by refrigerant flowing through the refrigerant circuit (9).

[0022] The refrigeration system (100) performs heating operation and cooling operation by switching the four-way selector valve (3). In the cooling operation, a first refrigeration cycle is performed. Specifically, the first port (P1) and the third port (P3) of the four-way selector valve (3) are in communication with each other, and the second port (P2) and the fourth port (P4) of the four-way selector valve (3) are in communication with each other (solid lines in FIG. 1 ). This causes the indoor heat exchanger (6) to function as an evaporator, and the outdoor heat exchanger (4) to function as a radiator. In the heating operation, a second refrigeration cycle is performed. Specifically, the first port (P1) and the fourth port (P4) of the four-way selector valve (3) are in communication with each other, and the second port (P2) and the third port (P3) of the four-way selector valve (3) are in communication with each other (dashed lines in FIG. 1 ). This causes the indoor heat exchanger (6) to function as a radiator, and the outdoor heat exchanger (4) to function as an evaporator.

[0023] -Compressor- As shown in Fig. 2, the compressor (1) includes a casing (10), a motor (20), a compression mechanism (30), and a shaft (70). The motor (20) and the compression mechanism (30) are housed in the casing (10). The compressor (1) is configured as a so-called high-pressure dome type in which refrigerant compressed in the compression mechanism (30) is discharged into an internal space (60) of the casing (10) and the internal space (60) becomes high pressure.

[0024] The motor (20) rotates the shaft (70). The motor (20) is housed in the casing (10). The motor (20) drives the compression mechanism (30). The motor (20) is, for example, an inner rotor motor. The motor (20) is disposed above the mounting plate (44) within the motor (20). The motor (20) has a cylindrical stator (21) that fits along the inner circumferential surface of the casing (10) and a rotor (22) that is disposed inside the stator (21). The stator (21) is fixed to the casing (10). The rotor (22) has a cylindrical rotor core (not shown) and six flat permanent magnets (not shown) embedded at intervals along the axial direction (R). The axial direction (R) is the rotation direction of the shaft (70). The shaft (70) is connected to a central hole in the rotor core.

[0025] The shaft (70) is disposed within the casing (10). Hereinafter, the direction in which the shaft (70) extends may be referred to as the axial direction (Z). In this embodiment, the axial direction (Z) is the vertical up-down direction, with one side (Z1) of the axial direction (Z) being the vertical up-down direction, and the other side (Z2) of the axial direction (Z) being the vertical down-down direction. The shaft (70) is driven by the motor (20) to rotate. The shaft (70) rotates in the axial direction (R) around the axis (70a) of the shaft (70). The shaft (70) is coupled to the rotor (22) of the motor (20). The shaft (70) includes an eccentric portion (71) that is eccentric with respect to the axis (70a) of the shaft (70). The shaft (70) is coupled to the compression mechanism (30). The shaft (70) is an example of a rotating shaft.

[0026] The compression mechanism (30) is accommodated in the casing (10). The compression mechanism (30) compresses the drawn refrigerant and discharges it into the internal space (60) of the casing (10). The rotation of the shaft (70) causes the compression mechanism (30) to compress the refrigerant. The compression mechanism (30) is disposed on the other side (Z2) of the motor (20) in the axial direction (Z). The compression mechanism (30) is fixed to a mounting plate (44). The mounting plate (44) is fixed to the casing (10). The mounting plate (44) is disposed between the motor (20) and the compression mechanism (30) in the axial direction (Z). The compression mechanism (30) includes a cylinder (34), a front head (41), a rear head (25), and a piston (35). The cylinder (34) has a suction port (55). The front head (41) closes an end of the cylinder (34) in the axial direction (Z). Specifically, the front head (41) closes an end of the cylinder (34) on the side where the motor (20) is located (the upper end surface of the cylinder (34)) in the axial direction (Z). The front head (41) is disposed between the motor (20) and the compression mechanism (30) in the axial direction (Z). The cylinder (34) has a cylinder chamber (34a) therein. In the cylinder chamber (34a), the drawn refrigerant is compressed and discharged. The piston (35) is accommodated in the cylinder (34). The piston (35) eccentrically rotates inside the cylinder chamber (34a).

[0027] The casing (10) is provided with a suction pipe (14) and a discharge pipe (15). The suction pipe (14) communicates with the outside of the casing (10) and the cylinder chamber (34a) via the suction port (55). The discharge pipe (15) communicates with the outside of the casing (10) and a space in the internal space (60) of the casing (10) that is located on one side (Z1) of the motor (20) in the axial direction (Z).

[0028] - Driving operation - In the compressor (1), when the motor (20) is started to rotate the rotor (22), the shaft (70) rotates. The rotation of the shaft (70) causes the compression mechanism (30) to compress the refrigerant. Specifically, the rotation of the shaft (70) causes the eccentric portion (71) to rotate eccentrically inside the cylinder chamber (34a), whereby the piston (35) revolves along the inner circumferential surface of the cylinder (34) while being restricted from rotating about its own axis. This causes a suction stroke and a discharge stroke to be performed alternately. In the suction stroke, refrigerant is drawn into the cylinder chamber (34a) from the suction pipe (14) through the suction port (55). In the discharge stroke, the refrigerant is compressed in the cylinder chamber (34a) and then discharged through a discharge port (not shown).

[0029] The refrigerant compressed by the compression mechanism (30) (the refrigerant discharged in the discharge stroke) flows in one direction (Z1) in the axial direction (Z) and passes through the motor (20). That is, as the motor (20) rotates, the refrigerant flows in one direction (Z1) in the axial direction (Z) and passes through the motor (20). The refrigerant that has passed through the motor (20) is discharged to the outside of the compressor (1) through the discharge pipe (15).

[0030] - Stator - FIG. 3 shows a perspective view of the stator (21). The coil (21d) is omitted from FIG. 3. As shown in FIG. 3, the stator (21) includes a stator core (21a), a first insulator (21b), a second insulator (21c), and a coil (21d) (see FIG. 4). The first insulator (21b) is attached to an end portion of the stator core (21a) on one side (Z1) in the axial direction (Z). The first insulator (21b) includes a first protrusion (21b1). A groove (21a11) is formed on the outer peripheral surface of the back yoke (21a1). The first protrusion (21b1) of the first insulator (21b) fits into the groove (21a11) of the back yoke (21a1), thereby attaching the first insulator (21b) to the stator core (21a). The second insulator (21c) is attached to an end portion of the stator core (21a) on the other side (Z2) in the axial direction (Z). The second insulator (21c) includes a second protrusion (21c1). The second protrusion (21c1) of the second insulator (21c) fits into the groove (21a11) of the back yoke (21a1), thereby attaching the second insulator (21c) to the stator core (21a).

[0031] The insulators (21b, 21c) are made of insulating resin such as LCP (Liquid Crystalline Polymer), PBT (Polybutylene Terephthalate), or PPS (Polyphenylene Sulfide).

[0032] Since the motor (20) is exposed to the refrigerant and the refrigerating machine oil, the insulators (21b, 21c) are made of a material whose insulating properties are less likely to deteriorate with the refrigerant and the refrigerating machine oil.

[0033] The stator core (21a) includes a cylindrical back yoke (21a1) and a plurality of teeth (21a2). The center line of the back yoke (21a1) overlaps with the axial center (70a) of the shaft (70). The center line of the back yoke (21a1) is an imaginary line passing through the centers of the openings at both ends of the back yoke (21a1). The plurality of teeth (21a2) protrude from the back yoke (21a1) toward the inside in the radial direction of the shaft (70). The radial direction of the shaft (70) is a direction that passes through the axial center (70a) of the shaft (70) and is perpendicular to the axial direction (Z). The inner radial direction of the shaft (70) is a direction that is perpendicular to the axial direction (Z) and toward the axial center (70a) of the shaft (70). The radially outer side of the shaft (70) is a direction perpendicular to the axial direction (Z) and away from the central axis (70a) of the shaft (70). The teeth (21a2) are aligned along the axial direction (R). A slot portion (S), which is a space, is located between adjacent teeth (21a2) in the axial direction (R). The slot portions (S) are aligned along the axial direction (R). Each of the slot portions (S) has a slot cell (21a3) formed along the inner circumferential surfaces of the teeth (21a2) and the back yoke (21a1) (see FIG. 5). The slot cell (21a3) insulates the stator core (21a) from the coil (21d). The slot cell (21a3) is made of a sheet-like resin material, such as a resin insulating film or a resin molded product (e.g., polyethylene terephthalate (PET)). A coil (21d) is wound around each of the teeth (21a2). The coils (21d) are arranged in the rotational direction (R).

[0034] Coils (21d) adjacent to each other in the axial direction (R) are arranged in the slots (S). A gap (SA) exists between the coils (21d) adjacent to each other in the axial direction (R). A gap (SA) exists for each slot (S).

[0035] In this embodiment, the coil (21d) is wound around each of the teeth (21a2) and is not wound across the teeth (21a2), which is what is called concentrated winding. In this embodiment, the motor (20) has what is called a six-pole, nine-slot configuration. When a current flows through the coil (21d), an electromagnetic force is generated in the stator (21), and this electromagnetic force rotates the rotor (22) (shown in FIG. 1) together with the shaft (70) (shown in FIG. 1). The number of poles and the number of slots of the motor (20) are not particularly limited.

[0036] -Cover material- As shown in FIGS. 4 and 5, the motor (20) includes a cover member (300). The cover member (300) is a cloth-like member. The cover member (300) is a strip-like member. The cover member (300) is made of a material that is permeable to varnish. The cover member (300) includes, for example, meta-aramid fiber. The cover member (300) is wound around the coil (21d) so as to cover a portion of the outer surface of the coil (21d). With the cover member (300) wound around the coil (21d), ends of the cover member (300) are fastened to the insulators (21b, 21c). This fixes the position of the cover member (300) relative to the coil (21d).

[0037] A cover member (300) is wound around each of the plurality of coils (21d). In this embodiment, one cover member (300) is wound around the plurality of coils (21d). This reduces the number of times that the end portions of the cover member (300) need to be fastened to the insulators (21b, 21c) compared to when one cover member (300) is wound around each of the coils (21d), and therefore makes it easier to wind the cover member (300) around the plurality of coils (21d). Note that one cover member (300) may be wound around each of the coils (21d).

[0038] The coil (21d) includes a covered portion (21d1) covered with the cover member (300) and an exposed portion (21d2) not covered with the cover member (300). The covered portion (21d1) is a portion of the coil (21d) located radially inward of the shaft (70). In the covered portion (21d1), the cover member (300) is wound around the coil (21d) from an end on one side (Z1) of the coil (21d) in the axial direction (Z) to an end on the other side (Z2) of the coil (21d). The exposed portion (21d2) is a portion of the coil (21d) located radially outward of the shaft (70). The exposed portion (21d2) is exposed to air. That is, a covered portion (21d1) of the coil (21d) located on the inner side in the radial direction of the shaft (70) is covered with the cover member (300), and an exposed portion (21d2) of the coil (21d) located on the outer side in the radial direction of the shaft (70) is exposed to air. In this embodiment, as shown in Fig. 4, the cover member (300) is wound around the plurality of coils (21d) such that all of the plurality of coils (21d) include the covered portion (21d1) and the exposed portion (21d2). Note that the cover member (300) may be wound around the plurality of coils (21d) such that some of the plurality of coils (21d) include the covered portion (21d1) and the exposed portion (21d2). In this case, the remaining portion of the coils (21d) may be entirely covered with the cover member (300), for example.

[0039] The cover member 300 is coated with or impregnated with varnish, so that the coil 21d can be fixed to the cover member 300 by the varnish.

[0040] As shown in FIG. 5, the tooth (21a2) includes a main body portion (21a21) and an inclined portion (21a22). The main body portion (21a21) extends radially. The inclined portion (21a22) is continuous with a radially inner end of the main body portion (21a21) and is inclined relative to the main body portion (21a21). The inclined portion (21a22) is located radially inner. The inclined portion (21a22) is inclined relative to the main body portion (21a21) so as to become farther away from the main body portion (21a21) as it moves radially inward. The coil (21d) is wound from the main body portion (21a21) to the inclined portion (21a22) of the tooth (21a2). In general, the portion of the coil (21d) wound around the inclined portion (21a22) is more likely to collapse than the portion wound around the main body portion (21a21) due to the inclination of the inclined portion (21a22). In this embodiment, the cover member (300) is wound around the coil (21d) so as to cover the covering portion (21d1), which is a portion of the coil (21d) located radially inward of the shaft (70). This allows the cover member (300) to effectively support the portion of the coil (21d) wound around the inclined portion (21a22). As a result, the portion of the coil (21d) wound around the inclined portion (21a22) is prevented from collapsing.

[0041] The cover member (300) may have a ring shape. In this case, the cover member (300) is made of a stretchable material in a ring shape, and when placed over the coil (21d), it contracts to come into close contact with the outer surface of the coil (21d).

[0042] -effect- As described above, the coil (21d) includes a covered portion (21d1) covered by the cover member (300) and an exposed portion (21d2) not covered by the cover member (300), with the covered portion (21d1) located on the radially inner side of the coil (21d) and the exposed portion (21d2) located on the radially outer side of the coil (21d). This allows the coil (21d) to be effectively supported by the cover member (300) covering the covered portion (21d1), while preventing the heat dissipation performance of the coil (21d) from being deteriorated by the exposed portion (21d2) of the coil (21d) that is not covered by the cover member (300) and is therefore exposed to the air.

[0043] Furthermore, by covering the covering portion (21d1) of the coil (21d) with the cover member (300), the coil (21d) can be prevented from bending, dust (iron powder, etc.) can be prevented from entering the coil (21d), and further, short-circuiting of the coil (21d) can be prevented.

[0044] In addition, the cover member (300) is coated with or impregnated with varnish. This allows the coil (21d) to be fixed to the cover member (300) by the varnish. Furthermore, it is possible to prevent a portion of the coil (21d) from floating. Even if a portion of the coil (21d) does float, the portion of the coil (21d) can be fixed by being fixed to the cover member (300) by the varnish. As a result, the coil (21d) can be stably positioned.

[0045] Furthermore, by fixing the coil (21d) to the cover member (300) with varnish, it is possible to suppress vibration of the coil (21d) when current is applied to the motor (20). Therefore, even if a foreign object gets into a gap in the coil (21d), damage to the coating of the coil (21d) due to the foreign object can be suppressed.

[0046] 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, the above embodiments, examples, modifications, and other embodiments may be combined or substituted as appropriate as long as the functionality of the subject matter of the present disclosure is not impaired.

[0047] 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]

[0048] As described above, the present disclosure is useful for motors, compressors, and refrigeration devices. [Explanation of symbols]

[0049] 1 Compressor 20 Motor 21a1 Back Yoke 21a2 Teeth 21a stator core 21d coil 21d1 Covering part 21d2 Exposed part 70 Shaft (rotating axis) 100 Refrigeration equipment 200 Resin parts 300 Cover member

Claims

1. A motor that rotates a rotary shaft (70), a stator core (21a) including a cylindrical back yoke (21a1) and teeth (21a2) protruding from the back yoke (21a1) radially inward of the rotary shaft (70); a coil (21d) wound around the tooth (21a2); a cover member (300) for covering a part of the coil (21d); Equipped with The coil (21d) includes a covered portion (21d1) covered with the cover member (300) and an exposed portion (21d2) not covered with the cover member (300), the covering portion (21d1) is located on the inner side of the coil (21d) in the radial direction, The motor, wherein the exposed portion (21d2) is located on the outer side of the coil (21d) in the radial direction.

2. The motor according to claim 1, wherein the cover member (300) is coated or impregnated with varnish.

3. 3. The motor according to claim 1, wherein the cover member (300) is permeable to varnish.

4. The motor according to claim 1 or 2, wherein the cover member (300) includes meta-aramid fibers.

5. The motor according to claim 1 or 2, wherein the cover member (300) has a ring shape.

6. A compressor comprising the motor according to claim 1 or 2.

7. A refrigeration device comprising the compressor according to claim 6.

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