KR20200081427A - Stator and electric motor having the stator - Google Patents

Abstract

The stator is provided with a stator iron core and a coil. The stator iron core is formed by laminating plural sheets of an annular first iron core sheet and an annular second iron core sheet. The first iron core sheet and the second iron core sheet each have a plurality of core pieces divided in the circumferential direction, and are in an annular shape by abutting the ends of the back yoke portions of adjacent core pieces. The first iron core sheet has a notched portion which forms a gap from an inner surface side to an intermediate portion in the radial direction from an inner surface side to an end portion of the adjacent back yoke portion, and a close contact portion against the end portion of the back yoke portion from the middle portion to the outer surface side. The second iron core sheet has a contact portion that abuts the end portion of the adjacent back yoke portion from the inner surface side to the outer surface side in the radial direction.

Description

Stator and electric motor having the stator

The present invention relates to a stator and an electric motor provided with the stator.

An electric motor used in a compressor or the like is composed of, for example, an annular stator and a rotor provided freely inside the stator, as disclosed in Patent Document 1. The stator is provided with an annular back yoke portion and a stator iron core having a plurality of tooth portions protruding inward from the back yoke portion, and a coil wound around the tooth portion of the stator iron core. The stator iron core is formed by laminating a plurality of toroidal iron core sheets. The iron core sheet has a plurality of core pieces divided in the circumferential direction, and has an annular shape by abutting the ends of the back yoke portions of adjacent core pieces.

Patent Document 1: Patent Publication No. 2013-42620

When the motor is assembled to the compressor, the stator is held by shrink fit on the inner surface of the hermetic container that forms the outer periphery of the compressor. If the stator has a configuration in which the ends of adjacent back yoke portions are brought into close contact with each other from the inner surface side to the outer surface side in the radial direction, the ends of the back yoke portions are brought into contact with each other when contracting and fitting to the inner surface of the sealed container. There is a possibility that the stress increases and the iron loss increases.

On the other hand, the stator is provided with a gap between the end portions of the adjacent back yoke portions from the inner surface side toward the outer surface side in the radial direction, thereby suppressing the end portions of the back yoke portions from contacting each other when shrink-fitting the inner surface of the sealed container. Since it can be done, iron loss can be suppressed. However, if the stator is provided with a gap from the inner surface side to the outer surface side in the radial direction, the rigidity decreases, so that the fastening force with the sealed container decreases, and there is a fear of increasing the noise of the compressor. Tightening force refers to weight loss and holding torque.

The present invention has been made to solve the problems as described above, and when shrink-fitting to the inner surface of the sealed container, it is possible to suppress an increase in iron loss caused by the end portions of the back yoke portions coming into contact with each other. An object of the present invention is to provide a stator capable of preventing deterioration of rigidity and suppressing an increase in noise of the compressor, and an electric motor provided with the stator.

The stator according to the present invention is wound around a stator iron core having an annular back yoke portion, a plurality of teeth portions protruding inwardly from the back yoke portion, and a teeth portion of the stator iron core. A coil is provided, and the stator iron core is formed by stacking a plurality of toroidal first iron core sheets and a toroidal second iron core sheet, and the first iron core sheet and the second iron core sheet. Each has a plurality of core pieces divided in the circumferential direction, and is in an annular shape by abutting the end portions of the back yoke portions of the adjacent core pieces, wherein the first iron core sheet is , Between the end portions of the adjacent back yoke portions, a notch portion forming a gap from the inner surface side toward the middle portion in the radial direction, and a contact portion abutting the end portion of the back yoke portion from the middle portion to the outer surface side, wherein the second The iron core sheet has a contact portion that abuts the end portion of the adjacent back yoke portion from the inner surface side to the outer surface side in the radial direction.

According to the present invention, in the first iron core sheet, the stator is contracted and fitted to the inner surface of the hermetic container because the notch portion is formed from the inner surface side, which is the portion where the magnetic flux is concentrated, toward the middle portion in the radial direction. , It is possible to suppress stress at the notch, and suppress iron loss. In addition, by providing the notched portion in the first iron core sheet, the outer diameter can be contracted to increase the stress of the contact portion, so that the stiffness of the contact portion can be increased. With this increase in stiffness, since the Young's modulus increases, the fastening force between the stator and the sealed container can be increased, and the noise of the compressor can be suppressed.

1 is a longitudinal sectional view showing a schematic configuration of a hermetic compressor having an electric motor with a stator according to an embodiment of the present invention.
2 is a plan view showing a stator iron core of a stator according to an embodiment of the present invention.
3 is a stator iron core of a stator according to an embodiment of the invention, in which a first iron core sheet is a longitudinal sectional view schematically showing a portion having a notch portion.
Fig. 4 is a longitudinal sectional view schematically showing a portion of a stator iron core of a stator according to an embodiment of the present invention, wherein the first iron core sheet has a contact portion.
5 is an enlarged view of a main part showing a connecting portion of a first iron core sheet of a stator according to an embodiment of the present invention.
6 is an enlarged view of a main part showing a connecting portion of a second iron core sheet of a stator according to an embodiment of the present invention.
7 is an enlarged view of a main part showing a connecting portion of a first iron core sheet as a conventional stator iron core.
8 is an enlarged view of a main part showing a connecting portion of a second iron core sheet as a conventional stator iron core.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings. In addition, in each figure, the same code|symbol is attached|subjected to the same or equivalent part, and the description is abbreviate|omitted or simplified suitably. In addition, regarding the structure described in each drawing, its shape, size, and arrangement can be appropriately changed within the scope of the present invention.

Embodiment.

1 is a longitudinal sectional view showing a schematic configuration of a hermetic compressor having an electric motor with a stator according to an embodiment of the present invention. 2 is a plan view showing a stator iron core of a stator according to an embodiment of the present invention. 3 is a longitudinal cross-sectional view schematically showing a portion of the stator core having a notch portion as a stator iron core of the stator according to the embodiment of the present invention. 4 is a longitudinal cross-sectional view schematically showing a portion of the stator core having a contact portion as a stator iron core of the stator according to the embodiment of the present invention. In Fig. 1, an example of the hermetic compressor 100 is a cylindrical rotary compressor. In the hermetic compressor 100, a compression element 2 for compressing a refrigerant gas and a transmission element 3 for driving the compression element 2 are housed inside the sealed container 1.

The closed container 1 is composed of a bottomed cylindrical lower container 10 and an upper container 11 covering the upper opening of the lower container 10 in a closed cylindrical shape. Inside the lower container 10, a compression element 2 is provided on the lower side, and a transmission element 3 is provided on the upper side. The compression element 2 and the transmission element 3 are connected by a crankshaft 12, and the rotational movement of the transmission element 3 is transmitted to the compression element 2. The compression element 2 compresses the refrigerant gas by the transmitted rotational force and discharges it into the sealed container 1. That is, the inside of the sealed container 1 is filled with compressed high-temperature and high-pressure refrigerant gas. Refrigerator oil for lubricating the compression element 2 is stored at the bottom of the hermetic container 1, that is, at the bottom of the lower container 10.

The compression element 2 is composed of a cylinder 20, a rolling piston 21, a main shaft support 22, a secondary shaft support 23, a discharge muffler 24, and a vane (not shown).

The cylinder 20 is provided with a cylinder chamber having a compression chamber and a suction chamber therein. The cylinder 20 is connected with a suction connector 25 through which suction gas from the refrigeration cycle passes through the suction muffler 26. Both ends of the cylinder chamber are opened in the axial direction.

The rolling piston 21 rotates eccentrically in the cylinder chamber. The rolling piston 21 is ring-shaped, and the inner circumference is slidably fitted to the eccentric shaft portion 12a of the crankshaft 12. That is, in the compression element 2, the rolling piston 21 that fits the eccentric shaft portion 12a of the crankshaft 12 is accommodated in the cylinder chamber, and reciprocally moves in the groove provided in the cylinder 20 in the radial direction. This is a configuration in which one end of the vane forms a compression chamber while adjoining the outer circumference of the rolling piston 21.

The main shaft receiving 22 slides the main shaft portion 12b of the crankshaft 12 freely and closes one opening of the cylinder chamber of the cylinder 20. A discharge muffler 24 is attached to the main shaft 22. The high-temperature/high-pressure discharge gas discharged from the discharge valve of the main spindle 22 enters the discharge muffler 24 and is discharged from the discharge hole 24a of the discharge muffler 24 into the sealed container 1. The supporting shaft 23 slides the auxiliary shaft portion 12c of the crankshaft 12 freely, and closes the other opening of the cylinder chamber of the cylinder 20.

The transmission element 3 is an electric motor provided with an annular stator 4 and a rotor 8 provided freely to rotate inside the stator 4. The transmission element 3 is composed of a brushless DC motor as an example.

The stator 4 is composed of a stator iron core 5 and a coil 7. 2, the stator iron core 5 has an annular back yoke portion 50 and a plurality of teeth portions 51 protruding inward from the back yoke portion 50. The stator iron core 5 alternately pluralizes the first iron core sheet 5A and the second iron core sheet 5B formed by punching an electromagnetic steel sheet of a thin plate, as shown in FIGS. 3 and 4. It is formed by lamination. The stator iron core 5 is formed with an outer diameter larger than the inner diameter of the middle portion of the lower container 10, and is fixed to the inner surface of the lower container 10 by shrink fit.

The first iron core sheet 5A has a plurality of core pieces 6 divided in the circumferential direction, and is configured to have an annular shape by abutting the ends of the back yoke portions 50 of the adjacent core pieces 6. Similarly, the second iron core sheet 5B also has a plurality of core pieces 6 divided in the circumferential direction, and is formed in a toroidal shape by abutting the ends of the back yoke portions 50 of adjacent core pieces 6. . The core piece 6 of the first iron core sheet 5A and the core piece 6 of the second iron core sheet 5B are rotatably connected by a rotating shaft portion 52.

5 is an enlarged view of a main part showing a connecting portion of a stator first iron core sheet according to an embodiment of the present invention. 6 is an enlarged view of a main part showing a connecting portion of the second iron core sheet of the stator according to the embodiment of the present invention. As shown in Fig. 5, the first iron core sheet 5A is provided with a notch portion 60 between the ends of adjacent back yoke portions 50 to form a gap from the inner surface side toward the middle portion in the radial direction. , From the middle portion to the outer surface side, has a contact portion 61 against the end of the back yoke portion 50. On the other hand, as shown in FIG. 6, the second iron core sheet 5B has a contact portion 62 that faces the end portion of the adjacent back yoke portion 50 from the inner surface side to the outer surface side in the radial direction. .

From the inner surface side, which is the part where the notch 60 is provided, to the middle part toward the radial direction, the magnetic flux is concentrated inside the stator 4 when the stator 4 is contracted and fitted to the sealed container 1. . On the other hand, when the stator 4 is contracted and fitted to the sealed container 1 from the middle portion to the outer surface side where the contact portion 61 is provided, the magnetic flux is not concentrated inside the stator 4. In this regard, the portion in which the magnetic flux is not concentrated is, for example, a range from the outer surface side of the stator 4 to about 2 mm in the radial direction. The portion where the magnetic flux concentrates is, for example, a range from the outer surface side of the stator 4 to the inner surface side from a position exceeding about 2 mm in the radial direction.

The coil 7 is wound around the teeth portion 51 of the stator iron core 5 through the insulating member 70. As shown in FIG. 1, the coil 7 is connected with a lead wire 71 for applying a voltage and flowing a current. The lead wire 71 is connected to the glass terminal 13 provided in the upper container 11, and receives power from the outside of the sealed container 1.

The rotor 8 includes a rotor iron core 80, a permanent magnet 81, an upper balance weight 82, a lower balance weight 83, and a rivet 84. The rotor iron core 80 is formed by stacking a plurality of iron core sheets formed by punching a thin steel plate. The permanent magnet 81 is inserted into a magnet insertion hole formed in the rotor iron core 80.

The upper balance weight 82 is disposed at the upper end portion of the rotor core 80. The lower balance weight 83 is disposed at the lower end of the rotor iron core 80. The upper balance weight 82 and the lower balance weight 83 are used for rotational movement of the rotor 8 caused by displacement of the rotational torque in a compression process such as suction, compression and discharge of the refrigerant gas of the compression element 2. It is prepared to correct unevenness. In addition, the upper balance weight 82 and the lower balance weight 83 also serve as a single plate that prevents scattering of the permanent magnet 81. The upper balance weight 82 and the lower balance weight 83 and the end plate may be separate parts.

The rivet 84 is to fix the upper balance weight 82, the lower balance weight 83, and the rotor iron core 80.

7 is an enlarged view of a main part showing a connecting portion of a first iron core sheet as a conventional stator iron core. 8 is an enlarged view of a main part showing a connecting portion of a second iron core sheet as a conventional stator iron core. The conventional stator iron core also has an annular back yoke portion 50 and a plurality of teeth portions 51 protruding inward from the back yoke portion 50. The stator iron core is formed by alternately stacking a plurality of annular first iron core sheets 5C and annular second iron core sheets 5D.

The first iron core sheet 5C and the second iron core sheet 5D each have a plurality of core pieces 6 divided in the circumferential direction, and the ends of the back yoke portions 50 of the adjacent core pieces 6 are It is a conical shape in a butt. As shown in Fig. 7, the first iron core sheet 5C has a gap 63 between the end portions of the adjacent back yoke portions 50 from the inner surface side to the outer surface side in the radial direction. 8, the 2nd iron core sheet 5D has the contact part 64 which contacted the end part of the adjacent back yoke part 50 from the inner surface side to the outer surface side toward the radial direction.

The stator having the stator iron core shown in FIGS. 7 and 8 is provided with a gap 63 in the first iron core sheet 5C, so that the outer surface of the stator is shrink-fitted to the inner surface of the sealed container 1. At this time, the ends of the back yoke portions 50 collide with each other, so that a situation in which the stress is increased can be suppressed and iron loss can be reduced. However, if the gap 63 is provided from the inner surface side to the outer surface portion in the radial direction from the inner surface side to the outer surface portion in the same way as the stator with the conventional stator iron cores shown in FIGS. 7 and 8, it is possible to reduce the iron loss. There is a fear that the stiffness is lowered. Therefore, there is a possibility that the fastening force between the stator and the hermetic container 1 decreases, and noise of the hermetic compressor increases.

On the other hand, the stator 4 according to the present embodiment is sealed because the notch portion 60 extends from the inner surface side, which is the portion where the magnetic flux is concentrated in the first iron core sheet 5A, to the middle portion in the radial direction. When shrink-fitting to the inner surface of the container 1, stress can be suppressed in the notch portion 60, and iron loss can be suppressed. In addition, the stator 4, by providing the notch portion 60 in the first iron core sheet 5A, can shrink the outer diameter and increase the stress of the contact portion 61, because of the contact portion 61 Stiffness can be increased. Since the Young's modulus increases with this increase in stiffness, the fastening force to the hermetic container 1 can be increased, and noise of the hermetic compressor 100 can be suppressed. In addition, since the stator 4 is provided with the contact portion 61 on the outer surface side from the middle portion, which is the portion where the magnetic flux is not concentrated inside, even when stress is generated in the contact portion 61 during shrink fit, , The deterioration of the magnetic properties of the electromagnetic steel sheet due to the stress can be suppressed, and iron loss can be suppressed. In addition, the stator 4 is stacked because the second iron core sheet 5B has a contact portion 62 facing the end portion of the back yoke portion 50 adjacent to the outer surface side in the radial direction from the inner surface side. While increasing the rigidity of the direction, the roundness of the inner diameter side can be increased, so that the structure can be stabilized.

In addition, in the stator 4 according to the present embodiment, the stator iron core 5 is formed by laminating plural pieces of the first iron core sheet 5A and the second iron core sheet 5B alternately, thereby forming the first iron core sheet. The effect of (5A) and the effect of the second iron core sheet (5B) can be effectively and effectively balanced.

Although the present invention has been described above based on the embodiment, the present invention is not limited to the configuration of the above-described embodiment. For example, although the hermetic compressor 100 has shown a cylindrical rotary compressor as an example, a compressor of another structure may be used. Further, the hermetic compressor 100 is not limited to the configuration shown, and may include other components. Moreover, although the stator iron core 5 showed the structure formed by laminating|stacking several 1st iron core sheet 5A and 2nd iron core sheet 5B alternately, it is not limited to this. For example, one configuration may be used, such as placing one second iron core sheet 5B each time two first iron core sheets 5A are arranged. In short, it is noted that the scope of the present invention (technical scope) also includes various changes, applications, and ranges of use made by a person skilled in the art in response to the need (申し添える).

1: sealed container
2: Compression element
3: Electric element (motor)
4: stator
5: stator iron core
5A, 5C: 1st iron core sheet
5B, 5D: Second iron core sheet
6: Core edition
7: coil
8: rotor
10: lower container
11: upper container
12: crankshaft
12a: eccentric shaft
12b: Spindle
12c: Shaft
13: glass terminal
20: cylinder
21: rolling piston
22: Spindle
23: Support
24: discharge muffler
24a: discharge hole
25: suction connector
26: suction muffler
50: back yoke part
51: Tisbu
52: rotating shaft
60: notch
61, 62: close contact
63: clearance
64: close contact
70: insulating member
71: lead wire
80: rotor iron core
81: permanent magnet
82: phase balance weight
83: low balance weight
84: rivet
100: hermetic compressor

Claims (3)

A stator iron core having an annular back yoke portion and a plurality of teeth portions protruding inward from the back yoke portion,
The stator is provided with a coil wound around the teeth of the iron core,
The stator iron core is formed by laminating a plurality of sheets of an annular first iron core sheet and an annular second iron core sheet,
The first iron core sheet and the second iron core sheet each have a plurality of core pieces divided in the circumferential direction, and are in an annular shape by abutting the ends of the back yoke portions of the adjacent core pieces,
The first iron core sheet is in close contact with an end portion of the back yoke portion between the adjacent end portion of the back yoke portion to form a gap from the inner surface side toward the middle portion in the radial direction, and from the intermediate portion to the outer surface side. Have wealth,
The second iron core sheet, the stator characterized in that it has a contact portion that abuts the end portion of the adjacent back yoke portion from the inner surface side to the outer surface side in the radial direction. According to claim 1,
The stator iron core is a stator characterized in that the first iron core sheet and the second iron core sheet are alternately stacked in plural. An electric motor comprising the stator according to claim 1 or 2, and a rotor freely provided inside the stator.

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