Compressor

Abstract

Suppresses a decrease in the holding force with which the inner peripheral surface of the cylinder portion of the compressor housing holds the outer peripheral surface of the stator core. 【Solution means】The compressor includes a compressor housing having a cylindrical cylinder portion, a compression portion disposed inside the compressor housing for compressing refrigerant, and a motor disposed inside the compressor housing. The motor has a rotor and a stator core disposed on the outer peripheral side of the rotor. The cylinder portion has a first welded portion to which the cylinder portion is joined along the axial direction of the rotation axis of the motor. The stator core has, in the circumferential direction of the stator core, a plurality of large-diameter portions that contact the inner peripheral surface of the cylinder portion, and a plurality of non-large-diameter portions whose distance from the center to the outer peripheral surface of the stator core is smaller than that of the large-diameter portions. When viewed from the axial direction of the rotation axis, the non-large-diameter portions are arranged on a first straight line passing through the center of the stator core and the first welded portion along the radial direction of the stator core.

Description

Technical Field

[0001] The present invention relates to a compressor.

Background Art

[0002] As a compressor, there is known one in which the outer peripheral surface of the stator core of a motor is fixed to the inner peripheral surface of a compressor housing in which the motor is disposed. This type of compressor has a structure in which a plurality of protruding portions protruding radially outward of the stator core are provided on the outer peripheral portion of the stator core (Patent Document 1). In this structure, by bringing each protruding portion of the stator core into contact with the inner peripheral surface of the compressor housing, the contact range (contact surface) in contact with the inner peripheral surface of the compressor housing in the circumferential direction of the stator core is reduced, and when the stator core is fixed in the compressor housing, the compressive stress applied from the compressor housing to the stator core is reduced, and deformation of the stator core is suppressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, generally, the compressor housing of a compressor is formed into a cylindrical shape by bending a rectangular iron plate, and a welding portion for joining both ends of the iron plate is provided, whereby a cylindrical body portion is formed (Patent Document 2). The body portion of the compressor housing formed in this way has a problem that the inner diameter on the straight line passing through the welding portion is large in the radial direction of the body portion, the inner diameter in the direction orthogonal to this straight line is small, and the inner peripheral surface of the body portion tends to be substantially elliptical in the circumferential direction of the body portion.

[0005] When the stator core is fixed to the inner peripheral surface of the barrel-shaped body that has become slightly elliptical, a gap may occur between the inner peripheral surface of the barrel-shaped body and the outer peripheral surface of the stator core in the radial direction of the barrel-shaped body along the straight line passing through the welded portion, and the holding force with which the inner peripheral surface of the barrel-shaped body holds the outer peripheral surface of the stator core may decrease. In particular, when the contact surface between the inner peripheral surface of the barrel-shaped body of the compressor housing and the stator core is reduced as in the structure of Patent Document 1, the decrease in the holding force with which the inner peripheral surface of the barrel-shaped body holds the outer peripheral surface of the stator core becomes remarkable.

[0006] The disclosed technology has been made in view of the above, and an object thereof is to provide a compressor capable of suppressing a decrease in the holding force with which the inner peripheral surface of the barrel-shaped body of the compressor housing holds the outer peripheral surface of the stator core.

Means for Solving the Problems

[0007] One aspect of the compressor disclosed in the present application includes a compressor housing having a cylindrical barrel-shaped body, a compression unit disposed inside the compressor housing for compressing refrigerant, and a motor disposed inside the compressor housing. The motor has a rotor and a stator core disposed on the outer peripheral side of the rotor. The barrel-shaped body has a first welded portion to which the barrel-shaped body is joined along the axial direction of the rotation axis of the motor. The stator core has a plurality of large-diameter portions in contact with the inner peripheral surface of the barrel-shaped body in the circumferential direction of the stator core, and a plurality of non-large-diameter portions whose distance from the center to the outer peripheral surface of the stator core is smaller than that of the large-diameter portions. When viewed from the axial direction of the rotation axis, the non-large-diameter portions are disposed on a first straight line passing through the center of the stator core and the first welded portion along the radial direction of the stator core.

Effects of the Invention

[0008] According to one aspect of the compressor disclosed in the present application, it is possible to suppress a decrease in the holding force with which the inner peripheral surface of the barrel-shaped body of the compressor housing holds the outer peripheral surface of the stator core.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the compressor disclosed in the present application will be described in detail with reference to the drawings. Note that the compressor disclosed in the present application is not limited by the following embodiments.

Embodiment

[0011] Figure 1 is a longitudinal sectional view showing the compressor according to the embodiment. As shown in FIG. 1, the compressor 1 is a so-called rotary compressor, and includes a container 2 as a compressor housing, a shaft 3 as a rotating shaft, a compression unit 5, and a three-phase motor 6.

[0012] The container 2 has a cylindrical body (main shell) 2a, a cup-shaped upper part (top shell) 2b, and a cup-shaped lower part (bottom shell) 2c. The body 2a, the upper part 2b, and the lower part 2c of the container 2 are formed of a metal material, and the upper part 2b is welded to the upper end of the body 2a, and the lower part 2c is welded to the lower end of the body 2a, thereby forming a sealed internal space 7. The internal space 7 is generally formed in a cylindrical shape. The container 2 is formed such that when it is placed vertically on a horizontal plane, the central axis of the cylinder forming the internal space 7 is parallel to the vertical direction. In the container 2, an oil reservoir 8 is formed at the lower part of the internal space 7. Refrigerating machine oil 8a, which is lubricating oil for lubricating the compression part 5, is stored in the oil reservoir 8. A suction pipe 11 as a suction part for sucking refrigerant and a discharge pipe 12 as a discharge part for discharging the compressed refrigerant are connected to the container 2. The shaft 3 as a rotating shaft is formed in a rod shape and is disposed in the internal space 7 of the container 2 such that one end is disposed in the oil reservoir 8. The shaft 3 is supported by the container 2 so as to be rotatable about the central axis of the cylinder forming the internal space 7. By rotating, the shaft 3 supplies the refrigerating machine oil 8a stored in the oil reservoir 8 to the compression part 5.

[0013] The compression part 5 is disposed at the lower part of the internal space 7 and above the oil reservoir 8. The compressor 1 further includes an upper muffler cover 14 and a lower muffler cover 15. The upper muffler cover 14 is disposed above the compression part 5 in the internal space 7. The upper muffler cover 14 forms an upper muffler chamber 16 inside. The lower muffler cover 15 is provided at the lower part of the compression part 5 in the internal space 7 and above the oil reservoir 8. The lower muffler cover 15 forms a lower muffler chamber 17 inside. The lower muffler chamber 17 communicates with the upper muffler chamber 16 through a communication passage (not shown) formed in the compression part 5. A compressed refrigerant discharge hole 18 is formed between the upper muffler cover 14 and the shaft 3, and the upper muffler chamber 16 communicates with the internal space 7 through the compressed refrigerant discharge hole 18.

[0014] The compression section 5 compresses the refrigerant supplied from the suction pipe 11 as the shaft 3 rotates, and supplies the compressed refrigerant to the upper muffler chamber 16 and the lower muffler chamber 17. The refrigerant is compatible with the refrigeration oil 8a. The three-phase motor 6 is disposed above the compression section 5 in the internal space 7.

[0015] FIG. 2 is a cross-sectional view showing the three-phase motor 6 of the compressor 1 of the embodiment. As shown in FIGS. 1 and 2, the three-phase motor 6 includes a rotor 21 and a stator 22. The rotor 21 is formed in a columnar shape by laminating a plurality of metal plates (not shown), and is integrated by a plurality of rivets 9. The shaft 3 is inserted through the center of the rotor 21, and the rotor 21 is fixed to the shaft 3. Six slit-shaped magnet embedding holes 10a are formed in the rotor 21 so as to form each side of a hexagon centering around the shaft 3. Each magnet embedding hole 10a is formed at a predetermined interval in the circumferential direction of the rotor 21. A plate-shaped permanent magnet 10b is embedded in the magnet embedding hole 10a.

[0016] The stator 22 is generally formed in a cylindrical shape and is disposed so as to surround the outer peripheral side of the rotor 21. The stator 22 includes an annular stator core 23, an upper insulator 24 and a lower insulator 25, and a plurality of windings 46 (see FIG. 1). The stator 22 and the container 2 are welded by a plurality of second welding portions 20, which will be described later, formed at intervals in the circumferential direction of the stator 22.

[0017] The upper insulator 24 is fixed to the upper end of the stator core 23. The lower insulator 25 is fixed to the lower end of the stator core 23. Also, as shown in FIGS. 1 and 2, an insulating film 26 is inserted along the inner peripheral surface of the slots between the respective stator core teeth portions 32-1 to 32-9, which will be described later, in the stator core 23. The stator core 23 and the winding 46 are insulated by the insulating film 26. The insulating film 26 is formed of a resin material such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or the like. Also, the upper insulator 24 and the lower insulator 25 are formed of a resin material and are insulating members that insulate the stator core 23 and the winding 46.

[0018] (Structure of the stator) FIG. 3 is a plan view showing the stator 22 of the three-phase motor 6 in the embodiment. As shown in FIG. 3, windings 46, which are electric wires, are wound around a plurality of stator core teeth portions 32-1 to 32-9, which will be described later, in the stator core 23. Winding portions 45 are respectively formed in the respective stator core teeth portions 32-1 to 32-9 by the respective windings 46. The three-phase motor 6 in the embodiment is a six-pole nine-slot concentrated winding type motor (see FIG. 2). The plurality of windings 46 include a plurality of U-phase windings 46-U1 to 46-U3, a plurality of V-phase windings 46-V1 to 46-V3, and a plurality of W-phase windings 46-W1 to 46-W3. Also, in the stator 22, the neutral line drawn out from each winding portion 45 and bundled into one is covered with an insulating tube and inserted into the gap between the winding portions 45 adjacent in the circumferential direction (the rotation direction of the rotor 21) of the stator 22 (see FIG. 2).

[0019] FIG. 4 is a plan view showing the stator core 23 in the embodiment. As shown in FIG. 4, the stator core 23 includes an annular yoke portion 31 and a plurality of stator core teeth portions 32-1 to 32-9 (also referred to as stator core teeth portions 32) as a winding cylinder portion, and is formed by laminating a plurality of metal plates. The metal plates are formed of a soft magnetic material such as a silicon steel sheet.

[0020] The yoke portion 31 is generally formed in a cylindrical shape. Among the plurality of stator core teeth portions 32-1 to 32-9, the first stator core teeth portion 32-1 is generally formed in a columnar shape. One end of the first stator core teeth portion 32-1 is continuously formed on the inner peripheral side of the yoke portion 31, that is, it is formed so as to protrude from the inner peripheral surface of the yoke portion 31 toward the central axis of the stator core 23. The stator core teeth portions 32-2 to 32-9 other than the first stator core teeth portion 32-1 among the plurality of stator core teeth portions 32-1 to 32-9 are also generally formed in a columnar shape, and protrude from the inner peripheral surface of the yoke portion 31 toward the central axis of the stator core 23, similar to the first stator core teeth portion 32-1. Further, the plurality of stator core teeth portions 32-1 to 32-9 are arranged at equal intervals of 40 degrees in the circumferential direction of the yoke portion 31 on the inner peripheral surface of the yoke portion 31. Hereinafter, the plurality of stator core teeth portions 32-1 to 32-9 of the stator core 23 are referred to as stator core teeth portions 32.

[0021] Also, as shown in FIG. 4, on the outer peripheral surface of the stator core 23, at positions corresponding to the respective stator core teeth portions 32 in the circumferential direction of the stator core 23, six first recesses 35 and three second recesses 36 are respectively provided as grooves through which the refrigerant oil 8a and the refrigerant in the container 2 pass in the axial direction of the stator core 23. In the circumferential direction of the stator core 23, two first recesses 35 are arranged so as to be located between adjacent second recesses 36. The three second recesses 36 are arranged at equal intervals in the circumferential direction of the stator core 23. Further, cutout grooves 36a for positioning and attaching the upper insulator 24 and the lower insulator 25 to the stator core 23 are formed in the three second recesses 36. The main part of the stator core 23 in the embodiment will be described later.

[0022] (Characteristic configuration of the compressor) Next, the characteristic configuration of the compressor 1 of the embodiment will be described. The characteristics of the embodiment include the shape of the stator core 23 in the three-phase motor 6 and the arrangement of the stator core 23 with respect to the circumferential direction of the barrel portion 2a deformed during the manufacturing process of the container 2.

[0023] (Deformation of the barrel portion) FIG. 5 is a side view showing the first welded portion 19 and the second welded portion 20 formed in the barrel portion 2a of the container 2 in the embodiment. FIG. 6 is a cross-sectional view for explaining the deformation that occurs when forming the barrel portion 2a of the container 2 in the embodiment.

[0024] In the manufacturing process of the container 2, a metal plate is formed into a cylindrical shape by bending, and both ends of the metal plate are joined by seam welding, whereby the first welded portion 19, which is a seam welded portion, is formed. As shown in FIG. 5, the first welded portion 19 extends along the axial direction of the shaft 3 of the three-phase motor 6 provided in the container 2, and the metal plates forming the barrel portion 2a are joined. Note that the first welded portion 19 is not limited to seam welding, and may be formed by other welding such as laser welding or gas welding, for example.

[0025] Next, the barrel portion 2a provided with the first welded portion 19 is subjected to a diameter expansion process so as to expand from the inner peripheral side of the barrel portion 2a to a predetermined inner diameter dimension. At this time, since the mechanical strength in the vicinity of the first welded portion 19 in the circumferential direction of the barrel portion 2a is higher than that of other portions in the circumferential direction of the barrel portion 2a, the barrel portion 2a is not uniformly expanded over the entire circumference.

[0026] As a result, as shown in FIG. 6, in the cross-section of the body portion 2a, it deforms so as to go toward the outside of the body portion 2a in the first direction connecting the first welded portion 19 and the center of the body portion 2a, and toward the inside of the body portion 2a in the second direction orthogonal to the first direction. The inner peripheral surface of the body portion 2a is likely to become a substantially elliptical shape having a major axis along the first direction. When a stator core 23 formed with a constant outer diameter is fitted onto such a body portion 2a, a gap is generated between the inner peripheral surface of the body portion 2a and the outer peripheral surface of the stator core 23 in the major axis direction (first direction) where the first welded portion 19 is located, thereby reducing the holding force with which the inner peripheral surface of the body portion 2a holds the outer peripheral surface of the stator core 23.

[0027] Therefore, in the embodiment, by making the outer diameter of the stator core 23 partially different in the circumferential direction of the stator core 23 and arranging the outer peripheral surface of the stator core 23 at a predetermined position with respect to the circumferential direction of the inner peripheral surface of the body portion 2a, the above-described reduction in the holding force is suppressed.

[0028] In the manufacturing process of the compressor 1 of the present embodiment, the stator 22 is temporarily fixed to the body portion 2a by shrink-fitting the body portion 2a of the container 2 onto the stator 22. As will be described later, in the stator core 23 of the embodiment, by reducing the area where the inner peripheral surface of the body portion 2a and the outer peripheral surface of the stator core 23 are in contact with each other in the circumferential direction of the body portion 2a, the compressive stress generated in the stator core 23 by the external force applied from the body portion 2a shrink-fitted to the stator 22 can be reduced.

[0029] After the stator 22 is temporarily fixed in the body portion 2a as described above, as shown in FIG. 5, it is spot welded to the body portion 2a and fixed by the second welding portion 20 which is the spot welding portion. In the embodiment, as shown in FIGS. 2 and 7, a plurality of second welding portions 20 are arranged at equal intervals in the circumferential direction of the stator core 23. Although details will be described later, since the plurality of second welding portions 20 are arranged at equal intervals, deformation of the stator core 23 into which the body portion 2a is shrink-fitted is suppressed. Further, as shown in FIG. 5, a plurality of second welding portions 20 are also provided at intervals in the axial direction of the stator 22 (the axial direction of the shaft 3). Note that the second welding portion 20 is not limited to spot welding, and may be formed by other welding such as laser welding or gas welding, for example.

[0030] (Large-diameter portion and non-large-diameter portion of stator core) FIG. 7 is a cross-sectional view for explaining a main part of the stator core 23 in the embodiment, and shows a contact state between the stator core 23 and the body portion 2a of the container 2. FIG. 8 is a cross-sectional view showing an enlarged part of FIG. 7 for explaining the first straight line L1 in the embodiment.

[0031] As shown in FIGS. 4 and 7, the stator core 23 of the stator 22 has, in the circumferential direction of the stator core 23, a plurality of large-diameter portions 37 in contact with the inner peripheral surface of the body portion 2a, and a plurality of non-large-diameter portions 38 whose distance from the center O of the stator core 23 to the outer peripheral surface is smaller than that of the large-diameter portions 37.

[0032] The non-large-diameter portion 38 has, along the circumferential direction of the stator core 23, a plurality of small-diameter portions 39 whose distance R2 from the center O of the stator core 23 to the outer peripheral surface is smaller than the distance R1 from the center O of the stator core 23 to the outer peripheral surface of the large-diameter portion 37, and a first recess 35 and a second recess 36 through which the refrigerant oil 8a passes. The first recess 35 and the second recess 36 are formed to be recessed toward the center O side of the stator core 23 from the outer peripheral surface of the small-diameter portion 39, and the distance from the center O of the stator core 23 to the outer peripheral surface is smaller than that of the small-diameter portion 39.

[0033] Further, each large-diameter portion 37 is fitted to the inner peripheral surface of the body portion 2a of the container 2 by an intermediate fit. By fitting the three large-diameter portions 37 to the body portion 2a by an intermediate fit, when the body portion 2a is shrink-fitted to the large-diameter portion 37 of the stator core 23, the portion receiving the external force from the body portion 2a is reduced and the external force applied from the body portion 2a is relaxed as compared with the case where the entire outer peripheral surface of the stator core 23 contacts the inner peripheral surface of the body portion 2a in the circumferential direction of the stator core 23. Each small-diameter portion 39 is fitted to the inner peripheral surface of the body portion 2a with a clearance so that a clearance G is provided between the small-diameter portion 39 and the inner peripheral surface of the body portion 2a in the radial direction of the stator core 23.

[0034] In the embodiment, the three large-diameter portions 37 are arranged at equal intervals of 120 degrees in the circumferential direction of the stator core 23 with respect to the central angle around the center O of the stator core 23. Further, in the embodiment, the six small-diameter portions 39 are arranged in pairs with each large-diameter portion 37 interposed therebetween in the circumferential direction of the stator core 23. The large-diameter portion 37 and the small-diameter portion 39 refer to a part in the circumferential direction on the outer peripheral surface of the annular yoke portion 31 of the stator core 23.

[0035] As shown in FIG. 4, in the circumferential direction of the stator core 23, the circumferential length W1 of the large-diameter portion 37 along the outer peripheral surface of the stator core 23 and the circumferential length W2 of the small-diameter portion 39 are formed to be approximately the same. Each large-diameter portion 37 and each small-diameter portion 39 are set such that the central angle around the center O of the stator core 23 is about 20 degrees.

[0036] In the circumferential direction of the stator core 23, the small-diameter range obtained by summing the circumferential lengths W2 of the plurality of small-diameter portions 39 along the outer peripheral surface of the stator core 23 is larger than the large-diameter range obtained by summing the circumferential lengths W1 of the plurality of large-diameter portions 37. That is, 6W2, which is the sum of the circumferential lengths W2 of the six small-diameter portions 39, is larger than 3W1, which is the sum of the circumferential lengths W1 of the three large-diameter portions 37. Thereby, in the circumferential direction of the stator core 23, the large-diameter range where the outer peripheral surface of the stator core 23 contacts the inner peripheral surface of the container 2 is reduced, and the external force applied from the container 2 to the stator core 23 during shrink fitting can be appropriately reduced.

[0037] As shown in FIGS. 7 and 8, when the distance (major radius) from the center O of the stator core 23, which is the center of rotation of the three-phase motor 6, to the outer peripheral surface of the large-diameter portion 37 is R1, and the distance (minor radius) from the center O to the outer peripheral surface of the small-diameter portion 39 is R2, the relationship R1 > R2 is satisfied. Further, in the body portion 2a deformed into a substantially elliptical shape, when the maximum distance (body maximum radius) from the center O to the inner peripheral surface of the body portion 2a along the major axis direction of the substantially elliptical shape is R3a, and the minimum distance (body minimum radius) from the center O to the inner peripheral surface of the body portion 2a along the minor axis direction of the substantially elliptical shape is R3b, the relationship R3a > R3b > R2 is satisfied. The distance R1 in the large-diameter portion 37 is formed to have a dimension that allows for an intermediate fit with respect to the minimum distance R3b of the body portion 2a. Further, each small-diameter portion 39 that is clearance-fitted to the inner peripheral surface of the body portion 2a of the container 2 has a clearance G (= R3a - R2, or R3b - R2) between the outer peripheral surface of the small-diameter portion 39 and the inner peripheral surface of the body portion 2a that is greater than 0 and less than or equal to 250 [μm]. The clearance G is set, for example, to 50 [μm] ≤ G ≤ 250 [μm].

[0038] In other words, when the body portion 2a of the container 2 is shrink-fitted onto the stator core 23, the contact portion where the outer peripheral surface of the stator core 23 contacts the inner peripheral surface of the body portion 2a is the large-diameter portion 37, and the non-contact portion where the outer peripheral surface of the stator core 23 does not contact the inner peripheral surface of the body portion 2a and is a clearance fit is the non-large-diameter portion 38 (for example, the small-diameter portion 39). The large-diameter portion 37 is a contact portion for temporarily fixing the stator core 23 inside the body portion 2a in the manufacturing process of the compressor 1, and at least two large-diameter portions 37 may be provided at appropriate positions in the circumferential direction of the stator core 23 for temporary fixing. That is, in the radial direction of the stator core 23, the portion that is formed large to bring the stator core 23 into contact with the body portion 2a is the large-diameter portion 37, and the portion that is formed small so as not to bring the stator core 23 into contact with the body portion 2a is the non-large-diameter portion 38. When using a 9-slot stator core 23 as in the embodiment, it is preferable to provide three large-diameter portions 37 as in the embodiment. With such a configuration, the large-diameter portions 37 can be arranged at equal intervals in the circumferential direction of the stator core 23.

[0039] (First straight line and second straight line) And in the compressor 1 of the embodiment, when viewed from the axial direction of the shaft 3, the non-large-diameter portion 38 is disposed on the first straight line L1 passing through the center O of the stator core 23 and the first welded portion 19 along the radial direction of the stator core 23. That is, the stator core 23 is positioned and provided such that any one of the small-diameter portion 39, the first recess 35, and the second recess 36, which is the non-large-diameter portion 38, is disposed on the first straight line L1.

[0040] In the barrel portion 2a deformed into a substantially elliptical shape, the inner diameter of the barrel portion 2a is maximum in the major axis direction of the substantially elliptical shape where the first straight line L1 is located, and the inner diameter of the barrel portion 2a is minimum in the minor axis direction of the substantially elliptical shape. For this reason, the large-diameter portion 37 in contact with the barrel portion 2a deformed into a substantially elliptical shape is separated from the first straight line L1 in the circumferential direction of the stator core 23 so as not to be disposed on the first straight line L1 where the inner diameter of the barrel portion 2a is maximum along the major axis direction. Therefore, it is possible to avoid the large-diameter portion 37 being disposed at a position on the first straight line L1 where the inner diameter of the barrel portion 2a is maximum in the barrel portion 2a deformed into a substantially elliptical shape. That is, the large-diameter portion 37 comes into contact with the barrel portion 2a at a position where the inner diameter of the barrel portion 2a is smaller than the inner diameter on the first straight line L1. Thereby, unlike the case where the large-diameter portion 37 is disposed on the first straight line L1, it is possible to prevent a gap from being generated between the outer peripheral surface of each large-diameter portion 37 in contact with the barrel portion 2a and the inner peripheral surface of the barrel portion 2a. For this reason, it is possible to suppress a decrease in the holding force with which the inner peripheral surface of the barrel portion 2a holds the outer peripheral surface (the outer peripheral surfaces of the large-diameter portions 37) of the stator core 23.

[0041] Also, in the compressor 1 of the embodiment, the small-diameter portion 39 is arranged on the first straight line L1. As a result, since the small-diameter portion 39 is arranged in the major axis direction of the substantially elliptical deformed body portion 2a, compared with the structure in which the first concave portion 35 and the second concave portion 36 are arranged on the first straight line L1, when the body portion 2a is shrink-fitted into the stator core 23, it is difficult for the body portion 2a to contact the small-diameter portion 39, and the compressive stress generated in the stator core 23 due to the contact between the small-diameter portion 39 and the body portion 2a can be reduced. As a result, the deformation of the stator core 23 can be suppressed, so that the magnetic balance in the circumferential direction of the stator core 23 is made uniform, and a decrease in the efficiency of the three-phase motor 6 can be suppressed. Note that at least one small-diameter portion 39 may be arranged on the first straight line L1, and the effect of reducing the compressive stress generated in the stator core 23 can be obtained.

[0042] Also, in the compressor 1 of the embodiment, when viewed from the axial direction of the shaft 3, a large-diameter portion 37 is arranged on a second straight line L2 that passes through the center O of the stator core 23 and is orthogonal to the first straight line L1 in the radial direction of the stator core 23. In the substantially elliptical deformed body portion 2a, the inner diameter of the body portion 2a is minimized in the minor axis direction of the substantially ellipse where the second straight line L2 is located. Therefore, since the large-diameter portion 37 is arranged on the second straight line L2, in the substantially elliptical deformed body portion 2a, the large-diameter portion 37 contacts the body portion 2a at the position where the inner diameter of the body portion 2a is minimized, so that the above-described holding force can be appropriately ensured.

[0043] Note that the first welded portion 19 formed on the body portion 2a is formed such that the width dimension along the circumferential direction of the body portion 2a on the outer peripheral surface of the body portion 2a is, for example, about 5 mm to 10 mm. Therefore, as shown in FIG. 8, in the circumferential direction of the body portion 2a, the first straight line L1 also exists between the first straight line L1 passing through one end 19a of the first welded portion 19 and the first straight line L1 passing through the other end 19b of the first welded portion 19, and a plurality of first straight lines L1 exist according to the width dimension of the first welded portion 19.

[0044] Therefore, in the embodiment, when viewed from the axial direction of the shaft 3, the non-large-diameter portion 38 being disposed on the first straight line L1 means that the stator core 23 is disposed in the body portion 2a such that all of the plurality of first straight lines L1 existing as described above pass through the non-large-diameter portion 38. That is, the stator core 23 is disposed in the body portion 2a such that the entire width dimension of the first welded portion 19 faces the non-large-diameter portion 38.

[0045] Also, regarding the second straight line L2 orthogonal to the first straight line L1, although there are a plurality of them as in the case of the first straight line L1, for the large-diameter portion 37 that is brought into contact with the body portion 2a for temporary fixing, it is sufficient that the large-diameter portion 37 is disposed on at least one of the plurality of second straight lines L2 when viewed from the axial direction of the shaft 3. From the viewpoint of enhancing the contact state between the body portion 2a and the large-diameter portion 37, it is desirable that the stator core 23 is disposed in the body portion 2a such that all of the plurality of second straight lines L2 pass through the large-diameter portion 37.

[0046] (Position of the second welded portion) Also, each of the plurality of second welded portions 20 where the stator core 23 and the body portion 2a are spot welded is disposed on any one of the plurality of non-large-diameter portions 38 excluding the first straight line L1. In other words, each of the plurality of second welded portions 20 is not disposed on the first straight line L1. In the embodiment, in the stator core 23 in which each large-diameter portion 37 is fitted into the body portion 2a by shrink fitting, the second welded portion 20 is disposed only on the small-diameter portion 39.

[0047] By welding the non-large-diameter portion 38 in this way, a tensile force that pulls the stator core 23 outward in the radial direction of the body portion 2a acts on the second welded portion 20, and tensile stress is generated in the stator core 23. By canceling out the compressive stress generated in the stator core 23 where the large-diameter portion 37 contacts the body portion 2a, deformation of the stator core 23 can be suppressed. Furthermore, in the embodiment, since the plurality of second welded portions 20 are arranged at equal intervals in the circumferential direction of the stator core 23, the effect of canceling out the compressive stress as described above is obtained evenly in the circumferential direction of the stator core 23, and the effect of suppressing deformation of the stator core 23 is enhanced.

[0048] In addition, since the second welding portion 20 is not disposed on the first straight line L1, it is possible to avoid welding at a position on the first straight line L1 where the gap between the inner surface of the body portion 2a and the outer peripheral surface of the stator core 23 becomes maximum in the circumferential direction of the body portion 2a. For this reason, when welding is performed on the first straight line L1 where the gap becomes maximum, the spatter that scatters during welding becomes large, and the problem of spatter adhering to the inside of the body portion 2a can be avoided.

[0049] The second welding portion 20 is not mainly for holding the stator core 23 in the body portion 2a, but for restricting the movement of the stator core 23. Therefore, it may be provided in at least one of the plurality of small-diameter portions 39. In other words, by providing at least one second welding portion 20 in any of the non-large-diameter portions 38 located between the large-diameter portions 37, it acts so as to cancel the compressive stress generated by the large-diameter portion 37 coming into contact with the body portion 2a, so that an effect of suppressing deformation of the stator core 23 can be obtained.

[0050] (Reinforcing portion of non-large-diameter portion) As shown in FIG. 7, in the stator core 23, caulking portions 28A are provided as reinforcing portions for increasing the mechanical strength of the non-large-diameter portion 38 in the vicinity of each of the plurality of second welding portions 20. In other words, the caulking portion 28A is provided in each of the small-diameter portions 39 joined to the body portion 2a by the second welding portion 20 among the plurality of small-diameter portions 39 included in the non-large-diameter portion 38, and is located in the vicinity of the second welding portion 20 in the circumferential direction and the radial direction of the small-diameter portion 39, that is, in the vicinity of the outer peripheral surface of the small-diameter portion 39. The caulking portion 28A is formed along the lamination direction (axial direction of the shaft 3) in a plurality of metal plates laminated so as to constitute the stator core 23, and joins the plurality of metal plates together.

[0051] When the caulking portion 28A is formed, it plastically deforms, and due to the work hardening effect that makes it difficult to deform, the mechanical strength of the small-diameter portion 39 where the second welded portion 20 is formed is increased. Thereby, deformation of the stator core 23 due to the compressive stress generated in the stator core 23 can be suppressed. Note that the reinforcing portion is not limited to the caulking portion 28A. Although not shown, for example, a part of the small-diameter portion 39, that is, a part of the metal plate, may be formed of a highly rigid reinforcing material. Further, in a part of the small-diameter portion 39, an enlarged portion (not shown) for making the width dimension of the small-diameter portion 39 along the circumferential direction of the stator core 23 larger than the width dimension of the large-diameter portion 37 may be formed as a reinforcing portion, and the rigidity of the small-diameter portion 39 is increased by the enlarged portion.

[0052] In addition, inside the caulking portion 28A, there are voids (not shown) in the stacking direction of the plurality of metal plates, and these voids also act as a heat-insulating space that insulates the heat transmitted to the stator core 23 during welding of the body portion 2a of the container 2 and the small-diameter portion 39. For this reason, the insulating film 26 disposed in the slot between the stator core teeth portions 32 can be prevented from melting due to the heat during welding of the second welded portion 20.

[0053] (Reinforcing portion of large-diameter portion) In each of the plurality of large-diameter portions 37 of the stator core 23, caulking portions 28B are provided as reinforcing portions for increasing the mechanical strength of the large-diameter portions 37, similar to the caulking portion 28A of the small-diameter portion 39. The caulking portions 28B provided in the large-diameter portions 37 are located at the center in the circumferential and radial directions of the large-diameter portions 37. Also in the caulking portions 28B of the large-diameter portions 37, similar to the caulking portion 28A of the small-diameter portion 39, they are formed along the stacking direction on the plurality of metal plates stacked to form the stator core 23, and bond the plurality of metal plates together. Also in the caulking portions 28B of the large-diameter portions 37, similar to the caulking portion 28A of the small-diameter portion 39, the mechanical strength of the small-diameter portion 39 is increased by the action of becoming difficult to deform due to work hardening. Thereby, deformation of the stator core 23 due to the compressive stress generated in the stator core 23 can be suppressed. Further, as the reinforcing portion of the large-diameter portion 37, it is not limited to the caulking portion 28B. Although not shown, for example, a part of the large-diameter portion 37, that is, a part of the metal plate, may be formed of a reinforcing material with high rigidity.

[0054] (Compressive stress applied to the stator core) The compressive stress applied to the stator core 23 of the embodiment from the body portion 2a of the container 2 will be described in comparison with the stator core 123 of the comparative example.

[0055] FIG. 9 is a diagram showing the distribution of compressive stress generated in the stator core 23 in the embodiment. FIG. 10 is a diagram showing the distribution of compressive stress generated in the stator core 123 in the comparative example. In FIGS. 9 and 10, as the negative numerical values shown in the figures become smaller, that is, as it approaches white from black, it shows that the compressive stress applied to the stator core 23 from the body portion 2a increases.

[0056] In the stator core 123 of the comparative example, the same parts as the stator core 23 of the embodiment are denoted by the same reference numerals as in the embodiment, and the description thereof is omitted. The stator core 123 in the comparative example includes nine outer peripheral portions 137 formed with a constant radius (the distance between the center O of the stator core 123 and the outer peripheral surface of the outer peripheral portion 137 is constant), and between each of the outer peripheral portions 137, one of the first concave portion 35 and the second concave portion 36 is formed in the same manner as in the embodiment. The outer peripheral portion 137 in the comparative example is formed so as to be press-fitted into the body portion 2a in the same manner as the large-diameter portion 37 in the embodiment.

[0057] Therefore, the stator core 23 of the embodiment has a structure in which it contacts the body portion 2a at three locations where there are three large-diameter portions 37, and the stator core 123 of the comparative example has a structure in which it contacts the body portion 2a at nine locations where there are nine outer peripheral portions 137.

[0058] Comparing FIG. 9 and FIG. 10, in the stator core 123 of the comparative example shown in FIG. 10, the compressive stress generated in the annular yoke portion 31 where nine outer peripheral portions 137 contact the body portion 2a is relatively large, and the compressive stress generated in the stator core tooth portion 32 is relatively small.

[0059] On the other hand, in the stator core 23 of the embodiment shown in FIG. 9, the compressive stress generated on the outer peripheral side of the three large-diameter portions 37 that contact the body portion 2a is about the same as that of the outer peripheral portion 137 in the comparative example, but the compressive stress generated on the inner peripheral side of the large-diameter portion 37 and the non-large-diameter portion 38 is as small as that of the stator core tooth portion 32 in the comparative example. That is, in the stator core 23 of the embodiment, the compressive stress generated in the yoke portion 31 excluding the outer peripheral side of the large-diameter portion 37 and the stator core tooth portion 32 is about the same as the compressive stress generated in the stator core tooth portion 32 in the comparative example. Therefore, according to the stator core 23 of the embodiment, the compressive stress generated in the yoke portion 31 due to the external force applied from the body portion 2a can be reduced.

[0060] Therefore, in the stator core 23 of the embodiment, since the compressive strain due to the compressive stress is reduced, the deformation of the stator core 23 is suppressed, and the distortion of the air gap between the stator core 23 and the rotor 21 can be suppressed. As a result, the magnetic balance in the circumferential direction of the stator core 23 is made uniform, and a decrease in the efficiency of the three-phase motor 6 can be suppressed.

[0061] (Effect of the embodiment) As described above, in the compressor 1 of the embodiment, the stator core 23 of the three-phase motor 6 has a plurality of large-diameter portions 37 that are in contact with the inner peripheral surface of the body portion 2a of the container 2 in the circumferential direction of the stator core 23, and a plurality of non-large-diameter portions 38 whose distance R2 from the center O to the outer peripheral surface of the stator core 23 is smaller than that of the large-diameter portions 37. When viewed from the axial direction of the shaft 3, the non-large-diameter portions 38 are arranged on a first straight line L1 passing through the center O and the first welded portion 19 of the stator core 23 along the radial direction of the stator core 23. Therefore, in the body portion 2a deformed into a substantially elliptical shape, the large-diameter portion 37 is avoided from being arranged at a position on the first straight line L1 where the inner diameter of the body portion 2a is the largest, and the large-diameter portion 37 comes into contact with the body portion 2a at a position where the inner diameter of the body portion 2a is smaller than the inner diameter on the first straight line L1. Thereby, different from the case where the large-diameter portion 37 is arranged on the first straight line L1, it is possible to prevent a gap from being generated between the outer peripheral surface of each large-diameter portion 37 in contact with the body portion 2a and the inner peripheral surface of the body portion 2a. For this reason, it is possible to suppress a decrease in the holding force with which the inner peripheral surface of the body portion 2a holds the outer peripheral surface (the outer peripheral surfaces of the large-diameter portions 37) of the stator core 23.

[0062] Further, in the compressor 1 of the embodiment, the stator core 23 has a plurality of second welded portions 20 where the inner peripheral surface of the body portion 2a and the outer peripheral surface of the stator core 23 are joined, and each of the plurality of second welded portions 20 is disposed at any one of a plurality of non-large-diameter portions 38 excluding the first straight line L1. By welding the non-large-diameter portion 38 in this way, a tensile force that pulls the stator core 23 radially outward of the body portion 2a acts on the second welded portion 20, and tensile stress is generated in the stator core 23. By offsetting the compressive stress generated in the stator core 23 where the large-diameter portion 37 contacts the body portion 2a with this tensile stress, deformation of the stator core 23 can be suppressed. In addition, since the second welded portion 20 is not disposed on the first straight line L1, welding at a position on the first straight line L1 where the gap between the inner surface of the body portion 2a and the outer peripheral surface of the stator core 23 becomes maximum in the circumferential direction of the body portion 2a can be avoided. For this reason, when welding is performed on the first straight line L1 where the gap becomes maximum, the spatter that scatters during welding becomes large, and the problem of spatter adhering to the inside of the body portion 2a can be avoided.

[0063] Further, in the compressor 1 of the embodiment, caulking portions 28A for increasing the mechanical strength of the non-large-diameter portions 38 (small-diameter portions 39) are provided in the vicinity of each of the plurality of second welded portions 20 on the stator core 23. Thereby, deformation of the stator core 23 due to the compressive stress generated in the stator core 23 can be suppressed. In addition, the voids present inside the caulking portions 28A also act as heat-insulating spaces that insulate the heat transmitted to the stator core 23 during welding of the body portion 2a and the small-diameter portion 39. For this reason, the insulating film 26 disposed in the slot between the stator core teeth 32 can be prevented from melting due to the heat during welding of the second welded portion 20.

[0064] Further, in the compressor 1 of the embodiment, the plurality of second welded portions 20 are arranged at equal intervals in the circumferential direction of the stator core 23. Thereby, the effect of offsetting the compressive stress generated in the stator core 23 by the tensile stress generated in the second welded portion 20 can be obtained evenly in the circumferential direction of the stator core 23, so the effect of suppressing deformation of the stator core 23 is enhanced.

[0065] Further, in the compressor 1 of the embodiment, when viewed from the axial direction of the shaft 3, the large-diameter portion 37 is disposed on a second straight line L2 that passes through the center O of the stator core 23 and is orthogonal to a first straight line L1 in the radial direction of the stator core 23. As a result, in the substantially elliptical-shaped body portion 2a, since the large-diameter portion 37 contacts the body portion 2a at the position where the inner diameter of the body portion 2a is minimized, an appropriate holding force for holding the inner peripheral surface of the body portion 2a against the outer peripheral surface (the outer peripheral surfaces of the large-diameter portions 37) of the stator core 23 can be ensured.

[0066] Further, in the compressor 1 of the embodiment, caulking portions 28B for enhancing the mechanical strength of the large-diameter portions 37 are provided for the respective large-diameter portions 37 of the stator core 23. Thereby, deformation of the stator core 23 due to compressive stress generated in the stator core 23 can be suppressed.

[0067] Further, in the compressor 1 of the embodiment, at least one small-diameter portion 39 is disposed on the first straight line L1 of the stator core 23. As a result, since the small-diameter portion 39 is disposed in the major axis direction of the substantially elliptical-shaped body portion 2a, compared with a structure in which the first concave portion 35 and the second concave portion 36 are disposed on the first straight line L1, it becomes difficult for the body portion 2a to contact the small-diameter portion 39 when the body portion 2a is shrink-fitted to the stator core 23, and the compressive stress generated in the stator core 23 due to the small-diameter portion 39 contacting the body portion 2a can be reduced. As a result, deformation of the stator core 23 can be suppressed, so that the magnetic balance in the circumferential direction of the stator core 23 is made uniform, and a decrease in the efficiency of the three-phase motor 6 can be suppressed.

[0068] Hereinafter, a modified example will be described with reference to the drawings. In the modified example, the same reference numerals as those in the embodiment are given to the same constituent members and the same structural portions as those in the embodiment, and the description thereof is omitted. The shape of the non-large-diameter portion of the stator core in the modified example is different from that in the embodiment.

[0069] (Modified Example) FIG. 11 is a cross-sectional view showing the stator core 123 of a modified example. As shown in FIG. 11, the stator core 51 of the modified example has a plurality of non-large-diameter portions 52 where the distance from the center O of the stator core 123 to the outer peripheral surface is smaller than the large-diameter portion 37. The non-large-diameter portions 52 are formed at a constant distance R5 along the circumferential direction of the stator core 123. The distance R5 of the non-large-diameter portions 52 is formed to be approximately the same as the distance R2 of the small-diameter portion 39 in the embodiment, or smaller than the distance R2. Also in the comparative example, as in the embodiment, the non-large-diameter portions 52 are arranged on the first straight line L1, and the large-diameter portion 37 is arranged on the second straight line L2.

[0070] Also, among the plurality of non-large-diameter portions 52, the body portion 2a is spot-welded to one non-large-diameter portion 52 to form the second welded portion 20. The gap between the outer peripheral surfaces of the plurality of non-large-diameter portions 52 and the inner peripheral surface of the body portion 2a functions as a groove through which the refrigerator oil 8a and the refrigerant in the container 2 pass. Also, for example, among the plurality of non-large-diameter portions 52, a notch groove 36a is formed on the outer peripheral surface of one non-large-diameter portion 52 for positioning and attaching the upper insulator 24 and the lower insulator 25 to the stator core 23.

[0071] Also in the modified example, by arranging the non-large-diameter portions 52 on the first straight line L1, as in the embodiment, in the body portion 2a deformed into a substantially elliptical shape, the large-diameter portion 37 is prevented from being arranged at the position on the first straight line L1 where the inner diameter of the body portion 2a is the largest, and is arranged at a position where the inner diameter of the body portion 2a is smaller than the inner diameter on the first straight line L1. Thereby, it is possible to prevent a gap from occurring between the outer peripheral surface of each large-diameter portion 37 in contact with the body portion 2a and the inner peripheral surface of the body portion 2a. For this reason, it is possible to suppress a decrease in the holding force with which the inner peripheral surface of the body portion 2a holds the outer peripheral surface of the stator core 23.

Explanation of Reference Numerals

[0072] 1 Compressor 2 Container (Compressor Housing) 2a Body Portion 3 Shaft (Rotating Shaft) 5 Compression Portion 6 Three-Phase Motor 19 First Welding Part 20 Second Welding Part 21 Rotor 22 Stator 23 Stator Core 28A Crimping Part (Reinforcing Part) 28B Crimping Part (Reinforcing Part) 35 First Recessed Part (Groove Part) 36 Second Recessed Part (Groove Part) 37 Large Diameter Part 38 Non - Large Diameter Part 39 Small Diameter Part L1 First Straight Line L2 Second Straight Line O Center R1, R2 Distance

Claims

1. A compressor housing having a cylindrical body portion, a compression portion disposed inside the compressor housing for compressing a refrigerant, and a motor disposed inside the compressor housing, The motor has a rotor and a stator core disposed on the outer peripheral side of the rotor, The body portion has a first welded portion to which the body portion is joined along the axial direction of the rotation axis of the motor, The stator core has, in the circumferential direction of the stator core, a plurality of large-diameter portions that contact the inner peripheral surface of the body portion, and a plurality of non-large-diameter portions whose distance from the center to the outer peripheral surface of the stator core is smaller than that of the large-diameter portions, A compressor in which, when viewed from the axial direction of the rotation axis, the non-large-diameter portions are arranged on a first straight line passing through the center of the stator core and the first welded portion along the radial direction of the stator core.

2. The stator core has a plurality of second welded portions where the inner peripheral surface of the body portion and the outer peripheral surface of the stator core are joined, Each of the plurality of second welded portions is arranged at any one of the plurality of non-large-diameter portions, excluding the first straight line, The compressor according to Claim 1.

3. Reinforcing portions for increasing the mechanical strength of the non-large-diameter portions are provided in the vicinity of each of the plurality of second welded portions on the stator core, The compressor according to Claim 2.

4. The plurality of second welded portions are arranged at equal intervals in the circumferential direction of the stator core, The compressor according to Claim 2.

5. When viewed from the axial direction of the rotation axis, the large-diameter portions are arranged on a second straight line passing through the center of the stator core and orthogonal to the first straight line in the radial direction of the stator core, The compressor according to Claim 1.

6. Reinforcing portions for increasing the mechanical strength of each of the plurality of large-diameter portions are provided on each of the plurality of large-diameter portions of the stator core, The compressor according to Claim 1.

7. The plurality of non-large-diameter portions include a plurality of small-diameter portions having an arcuate outer peripheral surface, and a plurality of groove portions formed along the axial direction of the rotation axis through which lubricating oil in the compressor housing passes, At least one of the small-diameter portions is arranged on the first straight line, The compressor according to any one of Claims 1 to 6.

Images