Electric motors and rotary compressors

Abstract

To provide a space-saving electric motor and rotary compressor that properly insulate between a coil mounted on an insulator and a neutral point.SOLUTION: An electric motor includes a rotor, a stator including a plurality of teeth around which a plurality of coils are respectively wound, in which the stator is disposed radially outward from the rotor, and an insulator attached to the stator, and a neutral point accommodating portion for accommodating a neutral point to which a predetermined number of neutral wires of the coil is connected is provided in the outer peripheral area of the insulator, the neutral point accommodation unit includes a first wall portion disposed on the coil side, and a second wall portion disposed radially outward of the first wall portion and spaced apart from the first wall portion, and the neutral point is housed between the first wall portion and the second wall portion. Also, a rotary compressor includes the electric motor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric motor and a rotary compressor. [Background technology]

[0002] Rotary compressors are used as compressors in air conditioners and the like. The rotary compressor includes an electric motor, a rotary compression mechanism, and a sealed container that houses the electric motor and the rotary compression mechanism. The electric motor and the rotary compression mechanism are connected via a shaft (crankshaft).

[0003] When a rotating magnetic field is generated in the stator of the electric motor, the rotor rotates. As the rotor rotates, the eccentric elements of the rotary compression mechanism (such as the eccentric part and rollers that engage with the crankshaft) also rotate. This causes the refrigerant introduced into the cylinder of the rotary compression mechanism to be compressed.

[0004] A brushless motor (e.g., a three-phase brushless motor) is used as the electric motor for a rotary compressor. The stator of the brushless motor has a plurality of teeth (slots). Furthermore, a coil is wound around each tooth to generate a rotating magnetic field in the stator.

[0005] When each phase (U phase, V phase, W phase) of such a brushless motor is star-connected, the neutral wires extending from the coils of different phases are electrically connected in a form such as being twisted together (the connection point of the neutral wires will be referred to as the "neutral point" below).

[0006] Here, various inventions have been proposed relating to methods of joining and accommodating the neutral point, from the viewpoints of not impairing the operating characteristics of the motor, ease of assembly of the motor, space saving, etc. Under these circumstances, an invention particularly relating to a method of accommodating (installing) the neutral point is disclosed, for example, in Patent Document 1 below. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2020-141495 Summary of the Invention [Problem to be solved by the invention]

[0008] The technology disclosed in Patent Document 1 relates to a brushless motor comprising a rotor, a stator, and a cylindrical insulator fixed to the end of the stator, the stator having a plurality of teeth, a winding portion wound around each of the plurality of teeth, a neutral wire provided on one end side of the winding portion, and a neutral point to which the plurality of neutral wires are electrically connected.

[0009] In addition, the insulator disclosed in Patent Document 1 is provided with a pull-in notch, and multiple neutral wires are pulled along the outer surface of the insulator and pass through the pull-in notch, being pulled from the outside to the inside of the insulator and the pulled-in multiple neutral wires are fixed.

[0010] More specifically, in the technology disclosed in Patent Document 1, the electrically connected bundle of neutral wires (neutral point) is covered with an insulating tube and positioned inside the insulator. At this time, the insulating tube and the winding portion (the coil wound around the stator) may come into contact with or be close to each other. Therefore, when the motor (in the case of Patent Document 1, a brushless motor) rotates and vibrations occur, it is conceivable that the two may rub against each other.

[0011] 8, there is provided a brushless motor having a connection terminal 814 for connecting neutral wires extending from multiple coils to an outer peripheral surface 813 of an insulator 812. According to this embodiment, the neutral point (connection terminal 814) is not located inside the insulator 812, and therefore the problem of the technique disclosed in Patent Document 1 does not occur.

[0012] However, there is a problem in terms of space saving because the connection terminal 814 protrudes outside the insulator 812. Furthermore, as a result of the connection terminal 814 being located outside the insulator 812, the neutral point, which is not electrically insulated, may be exposed to the outside. Therefore, when a conductor having a potential difference from the motor is disposed near the motor, it is necessary to place them a predetermined distance (insulation distance) apart to prevent current flow between them.

[0013] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an electric motor and a rotary compressor that can appropriately insulate between a coil attached to an insulator and a neutral point and that can save space. [Means for solving the problem]

[0014] In order to solve the above problem, the electric motor according to the present invention comprises: A rotor, a stator provided radially outward of the rotor and including a plurality of teeth around which a plurality of coils are wound; an insulator attached to the stator; Equipped with a neutral point accommodating portion for accommodating a neutral point to which neutral wires of a predetermined number of the coils are connected is provided in an outer peripheral region of the insulator, The neutral point housing section is a first wall portion disposed on the coil side; a second wall portion disposed radially outward from the first wall portion and spaced apart from the first wall portion; Equipped with The neutral point is accommodated between the first wall portion and the second wall portion. It is characterized by:

[0015] According to this aspect of the present invention, a neutral point, to which neutral wires of different phases are connected, is housed between a first wall portion and a second wall portion of the neutral point housing portion. Here, the first wall portion is interposed between the neutral point and the coil attached to the insulator. Furthermore, because the neutral point is housed inside the second wall portion, the neutral point does not protrude radially outward from the insulator, and at least the lateral area of ​​the neutral point is covered. As a result, even if vibration occurs, the neutral point does not come into contact with the coil. Furthermore, even if other conductors are placed near the insulator, the neutral point is properly insulated from the other conductors. This prevents situations such as a short circuit between the neutral point and the coil, and also contributes to space-saving motors.

[0016] In addition, in the electric motor according to the present invention, It is preferable that at least one of the first wall portion and the second wall portion is provided with an eaves portion disposed above the neutral point.

[0017] According to this aspect of the present invention, an eave portion is provided on at least one of the first wall portion and the second wall portion in the neutral point accommodating portion of the insulator, thereby preventing the neutral point once accommodated in the neutral point accommodating portion from detaching from the neutral point accommodating portion.

[0018] Furthermore, in the electric motor according to the present invention, The first wall portion is provided with the eaves portion, It is preferable that the topmost position of the second wall portion is lower than the eaves portion of the first wall portion.

[0019] According to this aspect of the present invention, the highest point of the second wall portion in the neutral point accommodating portion of the insulator is lower than the eaves portion of the first wall portion, so that the neutral point can be easily accommodated inside the neutral point accommodating portion from outside the motor.

[0020] Furthermore, in the electric motor according to the present invention, a neutral point mounting surface on which the neutral point is mounted is formed between the first wall portion and the second wall portion; It is preferable that the neutral point mounting surface has a slope portion that slopes downward.

[0021] According to this aspect of the present invention, the slope of the neutral point mounting surface guides the tip of the neutral point to the bottom side of the neutral point housing (a deep position in the housing area), thereby preventing the neutral point housed in the neutral point housing from becoming detached.

[0022] Further, the rotary compressor according to the present invention comprises: The electric motor; a rotary compression mechanism connected to the electric motor via a shaft attached to a rotor of the electric motor; The present invention is characterized by comprising:

[0023] According to this aspect of the present invention, a neutral point, to which neutral wires of different phases are connected, is housed between a first wall portion and a second wall portion of the neutral point housing portion. Here, the first wall portion is interposed between the neutral point and the coil attached to the insulator. Furthermore, because the neutral point is housed inside the second wall portion, the neutral point does not protrude radially outward from the insulator, and at least the lateral area of ​​the neutral point is covered. As a result, even if vibration occurs, the neutral point does not come into contact with the coil. Furthermore, even if other conductors are placed near the insulator, the neutral point is properly insulated from the other conductors. This prevents situations such as a short circuit between the neutral point and the coil, and also contributes to space-saving motors. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide an electric motor and a rotary compressor that can appropriately insulate between a coil attached to an insulator and a neutral point and that can save space. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a vertical cross-sectional view of a rotary compressor according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the stator according to the first embodiment. [Figure 3] FIG. 2 is a perspective view of a stator according to the first embodiment. [Figure 4]FIG. 3 is a partial perspective view of an upper insulator on which no coil is wound in the first embodiment. [Figure 5] FIG. 10 is a perspective view of a stator according to a second embodiment. [Figure 6] FIG. 10 is a perspective view of a stator according to a second embodiment. [Figure 7] FIG. 10 is a perspective view of a stator (modification) according to the second embodiment. [Figure 8] FIG. 1 is a schematic perspective view of a conventional brushless motor (stator). DETAILED DESCRIPTION OF THE INVENTION

[0026] [First embodiment] A rotary compressor according to an embodiment of the present invention will be described in detail below with reference to the drawings. First, the overall configuration of a rotary compressor 1 according to a first embodiment of the present invention will be described with reference to Fig. 1. Here, Fig. 1 is a vertical cross-sectional view of the rotary compressor 1.

[0027] 1, the rotary compressor 1 according to the first embodiment includes an electric motor 10 and a rotary compression mechanism 20 driven by the electric motor 10. The electric motor 10 and the rotary compression mechanism 20 are housed in a sealed container 30 made of steel plate and including a container body 31 and a lid 32.

[0028] The electric motor 10 housed in the sealed container 30 is disposed on one side (upper side in the height direction) of the sealed container 30. The rotary compression mechanism 20 is disposed on the other side (lower side in the height direction) of the sealed container 30.

[0029] The electric motor 10 is a brushless motor (e.g., a three-phase brushless motor) that includes a stator 11, a rotor 12, and a shaft 13 (a crankshaft corresponding to the rotation axis of the rotor 12). Here, the stator 11 includes a stator core 11a formed by stacking multiple electromagnetic steel plates in the height direction and having a doughnut shape in a plan view with a substantially cylindrical air space formed inside, and coils 11b.

[0030] The stator core 11a also includes a yoke portion and teeth extending radially inward from the yoke portion. The aforementioned coil 11b is wound around the teeth using a concentrated winding method. The stator 11 (stator core 11a) is also equipped with an upper insulator 112 attached to the stator core 11a and engaging with the winding end 111a (upper end) of the coil 11b, and a lower insulator 113 engaging with the winding end 111b (lower end) of the coil 11b. The insulators 112 and 113 insulate the teeth from the coil 11b.

[0031] The coil 11b is electrically connected to a terminal 33 attached to the lid 32 of the container 30. When power is supplied to the coil 11b from the terminal 33, a current flows through the stator coil 11b. This generates a rotating magnetic field that acts on the rotor 12, causing the rotor 12 to rotate.

[0032] Next, the rotor 12 includes a lamination (rotor core) 12a formed by stacking multiple electromagnetic steel plates, each having a generally circular shape in plan view, in the height direction, and permanent magnets provided within the lamination 12a. The lamination 12a of the rotor 12 is disposed in a cylindrical cavity formed inside the stator 11. At this time, a small gap is formed between the inner end of the stator 11 (the inner end of the teeth) and the outer surface of the rotor 12. Furthermore, a through-hole penetrating the rotor 12 in the height direction is formed in the center of the rotor 12. A shaft 13 is inserted into the through-hole and supports the rotor 12. Note that, although the rotary compressor 1 has been described as an example of a compressor equipped with the electric motor 10, the present invention is not limited thereto. The electric motor 10 of this embodiment may be provided in other equipment, such as a scroll compressor.

[0033] Next, the stator 11 of the first embodiment will be described with reference to Fig. 2 to Fig. 4. Fig. 2 is a plan view of the stator 11. Fig. 3 is a perspective view of the stator 11. Fig. 4 is a partial perspective view of the upper insulator 112 on which the coil 11b is not wound.

[0034] As described above, the stator 11 is equipped with an upper insulator 112 and a lower insulator 113, but the following description will focus on the upper insulator 112. Accordingly, the upper insulator 112 may be simply referred to as the "insulator 112."

[0035] As shown in Figures 2 to 4, the insulator 112 includes an outer portion 112a disposed radially outward, a flange portion 112b, and an insulator teeth portion 112c (see Figure 4) extending radially inward from the inner surface of the outer portion 112a and connecting to the flange portion 112b.

[0036] 2 to 4, the insulator 112 is provided on its outer circumferential region with a housing portion (neutral point housing portion) 120 for housing a neutral point 115 in which the neutral wires 114 of the plurality of coils 11b are bundled. In the case of the first embodiment, the neutral point 115 in which the neutral wire 114a of the coil 11b1 (for example, U phase), the neutral wire 114b of the coil 11b2 (for example, V phase), and the neutral wire 114c of the coil 11b3 (for example, W phase) are bundled is housed in the neutral point housing portion 120. The neutral point 115 is housed in the neutral point housing portion 120 while covered with an insulating tube.

[0037] Here, the neutral point housing section 120 of the first embodiment includes a first wall section 121 disposed on the coil 11b side, and a second wall section 122 disposed radially outward from the first wall section 121. The first wall section 121 and the second wall section 122 are spaced apart from each other. Furthermore, a notch 112k is provided adjacent to the first wall section 121. The neutral point 115 (neutral conductor 114) passes through the notch 112k and is housed in the neutral point housing section 120.

[0038] More specifically, first wall portion 121 is interposed between coil 11b attached to insulator 112 and neutral point 115. Furthermore, since neutral point 115 is located inside second wall portion 122, neutral point 115 does not protrude radially outward from insulator 112 as in conventional brushless motors, and at least the side areas of neutral point 115 are covered by second wall portion 122.

[0039] As a result, even if vibration occurs in the electric motor 10, the neutral point 115 does not come into contact with the coil 11b, and even if another conductor is placed near the insulator 112, the neutral point 115 is properly insulated from the other conductor. This prevents a situation such as a short circuit between the neutral point 115 and the coil 11b, and also enables the electric motor 10 to be made more compact.

[0040] In the first embodiment, an eaves portion 124 is provided at a predetermined position on the first wall portion 121. As shown in FIGS. 2 to 4, the eaves portion 124 extends radially outward from the first wall portion 121 (extending toward the second wall portion 122). As a result, the eaves portion 124 is located above the neutral point 115 accommodated in the neutral point accommodation portion 120 and faces the neutral point 115.

[0041] By providing the eaves portions 124 in this manner, it is possible to prevent the neutral point 115, once accommodated in the neutral point accommodation section 120, from becoming detached from the neutral point accommodation section 120. However, the form of the eaves portions 124 is not limited to a flat portion extending substantially horizontally from the first wall portion 121 as shown in the figure. Furthermore, although the first wall portion 121 in the first embodiment is provided at the top end of the first wall portion 121, it may be provided at another location as long as it is located above the neutral point 115. Furthermore, although the neutral point accommodation section 120 in the first embodiment has two eaves portions 124, the number of eaves portions 124 is not limited to this.

[0042] Furthermore, as shown in the drawings, the eaves portion 124 in the first embodiment is provided only on the first wall portion 121, but the arrangement of the eaves portion 124 is not limited to this. For example, the eaves portion 124 may be provided only on the second wall portion 122 (for example, at the top end of the second wall portion 122), or may be provided on both the first wall portion 121 and the second wall portion 122. Note that when the eaves portion 124 is provided on the second wall portion 122, it extends radially inward from the second wall portion 122 (extending toward the first wall portion 121).

[0043] Furthermore, it is preferable that the highest point of the second wall portion 122 is lower than the position of the eaves portion 124 of the first wall portion 121. With this structure, the neutral point 115 can be easily accommodated from the outside of the motor 10 (insulator 112) to the inside of the neutral point accommodating portion 120. As a result, the construction cost can be reduced.

[0044] In addition, a neutral point mounting surface 123 on which the neutral point is placed is provided between the bottom of the first wall portion 121 and the bottom of the second wall portion 122. Furthermore, as shown in Fig. 4, it is preferable that the neutral point mounting surface 123 has a slope portion 125 that slopes downward.

[0045] The position of the slope portion 125 is preferably on the tip side (the side farther from the cutout 112k) of the neutral point mounting surface 123. By providing the slope portion 125 on the neutral point mounting surface 123, the tip of the neutral point 115 is guided to the bottom side (the deep position in the housing area) of the neutral point housing portion 120. This makes it possible to prevent the neutral point 115 housed in the neutral point housing portion 120 from becoming detached.

[0046] [Second embodiment] Next, an electric motor (particularly, a stator) according to a second embodiment will be described with reference to Figs. 5 to 7. Fig. 5 is a perspective view of a stator 51 (3-phase 9-slot parallel connection) according to the second embodiment. Fig. 6 is a perspective view of a stator 61 (series connection) according to the second embodiment. Fig. 7 is a perspective view of a modified example of the stator 61.

[0047] The stators 51 and 61 according to the second embodiment correspond to a so-called split core type in which small sections of a split stator core are fitted together to form an integrated unit. In contrast, the stator 11 according to the first embodiment (see FIGS. 1 to 4) corresponds to an annular core type that is integrally molded into an annular shape. In this respect, the two embodiments differ.

[0048] As described above, the stator 51 corresponds to a three-phase, nine-slot parallel connection, and therefore three neutral points 515 (515a to 515c) are formed. Accordingly, the neutral point housing 520 of the second embodiment houses the three neutral points 515a to 515c. However, the number of slots and the number of neutral points 515 are not limited to this. The neutral point housing 520 of the second embodiment also includes a first wall 521, a second wall 522, and an eaves portion 524 provided on at least one of the first wall 521 and the second wall 522.

[0049] 5, the neutral point housing 520 of the second embodiment is provided in a continuous manner along the outer periphery of the insulator 512. However, the aspect of the neutral point housing 520 is not limited to this. As an example of another aspect, there is provided a plurality of (for example, three) neutral point housings 520 each housing a neutral point 515a to 515c, and any of the neutral point housings 520 is physically separated from the adjacent neutral point housings 520.

[0050] 6, the coils of each phase are connected in series, forming one neutral point 615. The neutral point housing portion 620 in the second embodiment is provided in a part of the outer circumferential region of the insulator 612. The neutral point housing portion 620 also includes a first wall portion 621, a second wall portion 622, and an eaves portion 624 provided on at least one of the first wall portion 621 and the second wall portion 622.

[0051] As shown in Fig. 6, the neutral point housing 620 of the second embodiment is formed across the outer periphery of two divided sections. However, the configuration of the neutral point housing 620 is not limited to this. For example, as shown in Fig. 7, the neutral point housing 620 may be formed in the outer periphery of one divided section.

[0052] The embodiments of the present invention have been described in detail. However, the above description is provided to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention may include modifications and improvements to the above-described embodiments without departing from the spirit of the present invention. The present invention also includes equivalents thereof. [Industrial Applicability]

[0053] The rotary compressor according to the present invention is used in, for example, home and commercial air conditioners, etc. However, its use is not limited to this. [Explanation of symbols]

[0054] 1...Rotary compressor 10...Electric motor 11, 51, 61... Stator 11a... Stator core 112, 113, 512, 612...Insulators 115,515,615…neutral point 120, 520, 620...Neutral point housing 121,521,621…First wall part 122,522,622…Second wall part 123...Neutral point mounting surface 124,524,624…Eaves 125...Slope section 12 Rotor 13. Rotor shaft 20 Rotary compression mechanism 21 Cylinder 211... Compression chamber 22 Eccentric part 23. Laura 30. Airtight container

Claims

1. A rotor, a stator provided radially outward of the rotor and including a plurality of teeth around which a plurality of coils are wound; an insulator attached to the stator; Equipped with a neutral point accommodating portion for accommodating a neutral point to which neutral wires of a predetermined number of the coils are connected is provided in an outer peripheral region of the insulator, The neutral point housing section is a first wall portion disposed on the coil side; a second wall portion disposed radially outward from the first wall portion and spaced apart from the first wall portion; Equipped with the neutral point is accommodated between the first wall portion and the second wall portion; a neutral point mounting surface on which the neutral point is mounted is formed between the first wall portion and the second wall portion; The neutral point mounting surface has a slope portion that slopes downward. An electric motor characterized by:

2. At least one of the first wall portion and the second wall portion is provided with an eaves portion disposed above the neutral point.

2. The electric motor according to claim 1.

3. The first wall portion is provided with the eaves portion, The topmost position of the second wall portion is lower than the eaves portion of the first wall portion.

3. The electric motor according to claim 2.

4. An electric motor according to any one of claims 1 to 3; a rotary compression mechanism connected to the electric motor via a shaft attached to a rotor of the electric motor; A rotary compressor comprising:

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