WO2017154087A1

WO2017154087A1 - Electric motor stator and electric motor

Info

Publication number: WO2017154087A1
Application number: PCT/JP2016/057069
Authority: WO
Inventors: 増本　浩二
Original assignee: 三菱電機株式会社
Priority date: 2016-03-08
Filing date: 2016-03-08
Publication date: 2017-09-14
Also published as: CN208691029U; JPWO2017154087A1; JP6598978B2

Abstract

An electric motor stator and an electric motor of the present invention are provided with: a core piece comprising a plurality of laminated magnetic steel sheets each having a core back portion and a tooth portion projecting from the core back portion toward the inner circumferential surface; and a joining band for fastening the magnetic steel sheets in the lamination direction. Openings are provided in the outer circumferential surface of the joining band.

Description

Electric motor stator and electric motor

The present invention relates to an electric motor stator and an electric motor used for a compressor, a fan motor and the like.

Conventional stators of electric motors are formed by laminating electromagnetic steel sheets in which an iron core is integrally punched by a press or the like. As a method for fastening laminated electromagnetic steel sheets, a method of forming dowels by caulking the electromagnetic steel sheets in a press die and caulking the upper and lower electromagnetic steel sheets (clamping) and a method of welding are common. (For example, refer to Patent Documents 1 and 2). In addition, there has been proposed one in which an iron core is divided into a plurality of iron core pieces in consideration of high density winding and productivity (for example, see Patent Document 3). Patent Document 3 discloses a stator that is joined by attaching a joining band when joining the divided iron core pieces. In this case, the stator is joined by caulking or the like.

JP 2008-43102 A Japanese Patent Laid-Open No. 7-7875 JP 59-6736 A

As in Patent Documents 1 to 3, when punching or welding is performed, the electrical insulation at the joint of the laminated electrical steel sheets deteriorates. When the electrical insulation of the joint portion deteriorates, the electrical steel plates conduct, and eddy currents are generated at the conducting locations. This eddy current becomes heat due to the electrical resistance in the iron core and causes loss of electromagnetic energy (eddy current loss). When the frequency is increased to realize high-speed operation, the eddy current loss increases dramatically, and the efficiency of the motor is greatly reduced.

An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide an electric motor stator and an electric motor that suppress the generation of eddy currents in fastening of laminated electromagnetic steel sheets and has high energy efficiency. Is.

The stator of the electric motor according to the present invention fastens the plurality of electromagnetic steel plates in the stacking direction with an iron core piece composed of a plurality of laminated electromagnetic steel plates having a core back portion and a teeth portion protruding from the core back portion to the inner peripheral surface. A bonding band, and an opening is provided on an outer peripheral surface of the bonding band.

According to the stator and the motor of the electric motor according to the present invention, the opening is provided on the outer peripheral surface of the bonding band. Since there is no magnetic substance in the opening, the magnetic permeability of this portion is reduced, and the resistance (magnetic resistance) to the flow of magnetic flux is increased. Therefore, the magnetic flux flows around the opening, and the region where the magnetic flux flows on the outer peripheral surface of the bonding band is narrowed. And since the area | region where a magnetic flux flows becomes narrow, the generation | occurrence | production area | region of an eddy current also becomes narrow and an eddy current can be suppressed. In addition, eddy currents flow through the entire conductor at low frequencies, but flow more on the conductor surface at high frequencies. In general, the eddy current generated is small in a portion where the electrical insulation resistance is high. According to the stator and the motor of the electric motor according to the present invention, it is possible to increase the resistance at the opening on the outer peripheral surface of the bonding band and to make the eddy current difficult to flow with respect to the eddy current at high frequency. Therefore, eddy current loss is suppressed, energy loss of the electric motor is reduced, and efficiency is improved.

It is a top view of the electric motor using the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a top view of the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a top view of the iron core piece of the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a front view of the iron core piece of the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a top view of the core piece which inserted the joining band of the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a front view of the iron core piece which inserted the joining band of the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a left view of the iron core piece which inserted the joining band of the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a figure explaining the flow of the magnetic flux of the stator of the conventional electric motor. It is a figure explaining the flow of the magnetic flux of the stator of the electric motor which concerns on Embodiment 1 of this invention. It is a figure explaining the flow of the magnetic flux of the stator of the electric motor which concerns on Embodiment 2 of this invention. It is a figure explaining the flow of the magnetic flux of the stator of the electric motor which concerns on Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a plan view of an electric motor using the stator of the electric motor according to Embodiment 1 of the present invention. The electric motor 300 includes a stator 100 and a rotor 150. The rotor 150 has a magnet 151, and the stator 100 has a winding 2. The electric motor 300 is a permanent magnet type electric motor, but may be other types of electric motors such as an electromagnet type, a reluctance type, and a hysteris type.

FIG. 2 is a plan view of the stator of the electric motor according to Embodiment 1 of the present invention. FIG. 3 is a plan view of the iron core piece of the stator of the electric motor according to Embodiment 1 of the present invention. FIG. 4 is a front view of the iron core piece of the stator of the electric motor according to Embodiment 1 of the present invention. In the stator 100 of FIGS. 2 to 4, a plurality of arc-shaped iron core pieces 101 are joined in an annular shape. In FIG. 2, nine iron core pieces 101 are joined on the ring, but the number of iron core pieces constituting the ring is arbitrary, and one annular iron core that is not divided is used. It may be a piece.

The iron core piece 101 is formed by laminating a plurality of electromagnetic steel plates 104 in the vertical direction (Z-axis direction in FIG. 4). The core piece 101 has a core back portion 103 that is positioned on the outer peripheral side of the stator 100 and becomes a core back when the stator 100 is formed, and a teeth portion 102 that protrudes from the core back portion 103 to the inner peripheral surface. ing.

A winding 2 is wound around the tooth portion 102 via the insulating member 1 (see FIGS. 1 and 2). A groove 105 extending in the stacking direction of the electromagnetic steel plates 104 (Z-axis direction in FIG. 4) is formed on the outer periphery of the core back portion 103. The groove 105 shown in FIGS. 2 and 3 is a square groove, but is not limited to this, and as long as the same function can be performed, a U-shaped groove, a V-shaped groove, and a semicircle are provided. It can be changed to various cross-sectional grooves such as a round groove.

FIG. 5 is a plan view of the iron core piece into which the joining band of the stator of the electric motor according to Embodiment 1 of the present invention is inserted. FIG. 6 is a front view of the iron core piece into which the joining band of the stator of the electric motor according to Embodiment 1 of the present invention is inserted. FIG. 7 is a left side view of the iron core piece into which the joining band of the stator of the electric motor according to Embodiment 1 of the present invention is inserted. 5 to 7, the bonding band 3 is inserted into the groove 105 of the iron core piece 101 shown in FIGS. The joining band 3 is a prism that extends in the laminating direction (the Z-axis direction in FIGS. 4 and 6) of the electromagnetic steel sheet 104, and the upper end 4 and the lower end 5 in the laminating direction protrude in an inner circumferential surface direction. It is formed into a shape. The joining band 3 is inserted into the groove 105 shown in FIG. 3, and the laminated electromagnetic steel plates 104 constituting the iron core piece 101 are caulked and fastened by the upper end portion 4 and the lower end portion 5.

An opening 7 is formed on the surface of the outer peripheral surface 6 of the bonding band 3. Specifically, a plurality of openings 7 are arranged in the stacking direction of the electromagnetic steel sheets 104 (Z-axis direction in FIG. 6). Moreover, the arrangement | positioning of the opening part 7 is single in the circumferential direction (X-axis direction of FIG. 6). Furthermore, the opening 7 has a shape that is longer in the stacking direction than in the circumferential direction. In addition, arrangement | positioning and shape of the opening part 7 are not limited to what was described in drawing, It can change into various shapes, as long as the same function can be performed. For example, the arrangement of the openings 7 may be singular in the stacking direction of the electromagnetic steel sheets 104 (Z-axis direction in FIG. 6). Further, a plurality may be arranged in the circumferential direction (X-axis direction in FIG. 6). Furthermore, the opening 7 may have a shape that is longer in the circumferential direction than the width in the stacking direction. The width in the stacking direction and the width in the circumferential direction may be the same. Furthermore, the opening part 7 should just have an opening in the surface of the outer peripheral surface part 6 of the joining band 3, and the opening may be a dent recessed in the inner peripheral surface direction, and may be a through-hole.

The bonding band 3 is preferably made of austenitic stainless steel or non-ferrous metal having a relative permeability of 1.01 or less. For example, the bonding band 3 is preferably composed of a SUS304 plate, a copper plate, a brass plate, an aluminum plate, or the like. If the bonding band 3 is made of such a material having a relative permeability of 1.01 or less, the magnetic resistance is sufficiently high with respect to the electromagnetic steel sheet, and no magnetic flux flows through the bonding band 3. Moreover, since these metals have appropriate strength and heat resistance, they can be constructed without having to increase the thickness and width of the bonding band 3.

The bonding band 3 may be made of engineering plastic. For example, the bonding band 3 is made of PPS, PBT, LCP, or PEEK material. Such an engineering plastic has a sufficiently low relative permeability with respect to a metal member, a sufficiently high magnetic resistance with respect to an electromagnetic steel sheet, and a magnetic flux does not flow through the bonding band 3. In addition, since the metal is light and has high electrical corrosion resistance, a long-life and lightweight motor can be obtained.

Here, the flow of magnetic flux and eddy current during operation of the stator will be described. FIG. 8 is a diagram for explaining the flow of magnetic flux in the stator of a conventional electric motor. The magnetic flux that flows through the stator 110 includes an outward radial magnetic flux 111 that extends from the center toward the circumference, a circumferential magnetic flux 112 that flows in the circumferential direction, and an inward radial magnetic flux 113 that extends from the circumference toward the center. The direction of the magnetic flux is changed by changing + and-of the voltage applied to the electric motor, and the arrangement of the N pole and the S pole is spatially moved to generate a rotating magnetic field. And the torque which rotates a rotor (not shown) by generation | occurrence | production of a rotating magnetic field generate | occur | produces. At this time, an eddy current is generated perpendicular to the direction in which the magnetic flux flows. In the bonding band 33, a circumferential eddy current 122 and an inward radial eddy current 123 perpendicular to the magnetic flux are generated by the circumferential magnetic flux 112 and the inward radial magnetic flux 113. Although not shown, an outward radial eddy current is similarly generated with respect to the outward radial magnetic flux 111.

FIG. 9 is a diagram for explaining the flow of magnetic flux in the stator of the electric motor according to Embodiment 1 of the present invention. The magnetic flux that flows through the stator 100 includes an outward radial magnetic flux 11 that extends from the center toward the circumference, a circumferential magnetic flux 12 that flows in the circumferential direction, and an inward radial magnetic flux 13 that extends from the circumference toward the center. The circumferential eddy current 22 is an eddy current generated by the circumferential magnetic flux 12 in the bonding band 3, and the inward radial eddy current 23 is an eddy current generated by the inward radial magnetic flux 13. Although not shown, an outward radial eddy current is similarly generated with respect to the outward radial magnetic flux 11.

In the stator of the electric motor according to Embodiment 1 of the present invention, an opening 7 is provided in the joining band 3. Since there is no magnetic substance in the opening 7, the magnetic permeability of this portion is reduced, and the resistance (magnetic resistance) to the flow of the circumferential magnetic flux 12 is increased. Therefore, the circumferential magnetic flux 12 bypasses the opening 7 and flows through the non-opening 8, and the region where the circumferential magnetic flux 12 flows in the bonding band 3 becomes narrower. And since the area | region where the circumferential direction magnetic flux 12 flows becomes narrow, the generation | occurrence | production area | region of the circumferential direction eddy current 22 also becomes narrow, and generation | occurrence | production of the circumferential direction eddy current 22 can be suppressed. In addition, eddy currents flow through the entire conductor at low frequencies, but flow more on the conductor surface at high frequencies. In general, the generated eddy current is reduced in a portion where the electrical insulation resistance is high. In the stator of the electric motor according to Embodiment 1 of the present invention, the opening 7 is provided in the bonding band 3 to create a portion having a high insulation resistance against eddy currents at high frequencies. Therefore, even if circumferential eddy current 22, inward radial eddy current 23 and outward radial eddy current (not shown) generated by circumferential magnetic flux 12, outward radial magnetic flux 11 and inward radial magnetic flux 13 are generated. It is difficult for the openings 7 to have high electrical insulation resistance to flow, and eddy currents can be suppressed. Therefore, eddy current loss is suppressed, energy loss of the electric motor is reduced, and efficiency is improved.

Also, by inserting the bonding band 3 into the groove 105 of the iron core piece 101, the position of the electromagnetic steel sheet 104 is fixed, and the electromagnetic steel sheet 104 is less likely to be displaced. Therefore, the iron core piece 101 on which the electromagnetic steel sheets 104 are laminated does not fall down or bend, and the shape accuracy in the lamination direction of the iron core piece 101 can be improved. Therefore, the productivity of windings and the like due to the shape accuracy is improved, and mechanical vibration and noise of the electric motor can be reduced and stabilized. Therefore, it is possible to obtain an electric motor with high efficiency, low vibration, low noise and high productivity.

Embodiment 2. FIG.
FIG. 10 is a diagram for explaining the flow of magnetic flux in the stator of the electric motor according to Embodiment 2 of the present invention. 10, parts having the same configurations as those of the stators of FIGS. 2 to 9 are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 10, the magnetic flux flowing through the stator 120 has an outward radial magnetic flux 211 from the center toward the circumference, a circumferential magnetic flux 212, and an inward radial magnetic flux 213 from the circumference toward the center.

As shown in FIG. 10, in the bonding band 43, a plurality of openings 17 are arranged in the circumferential direction, and the openings 17 and the non-openings 18 are shifted. Since the opening 17 is arranged in this way, the path in the circumferential direction is blocked, and the circumferential magnetic flux 212 is less likely to flow, and the circumferential eddy current 222 can be suppressed. Further, since the opening portion 17 having an electrically high insulation resistance is displaced and a plurality of locations through which current flows can be blocked, the flow of the inward radial eddy current 223 with respect to the inward radial magnetic flux 213 is further hindered. Current can be suppressed. Although not shown, the outward radial eddy current with respect to the outward radial magnetic flux 211 can be similarly suppressed. Therefore, eddy current loss is suppressed, energy loss of the electric motor is reduced, and efficiency is improved.

Further, like the stator of the electric motor according to the first embodiment of the present invention, the productivity of windings and the like due to the shape accuracy is improved, and mechanical vibration and noise of the electric motor are reduced and stabilized. Is possible. Therefore, it is possible to obtain an electric motor with high efficiency, low vibration, low noise and high productivity.

Embodiment 3 FIG.
FIG. 11 is a diagram for explaining the flow of magnetic flux in the stator of the electric motor according to Embodiment 3 of the present invention. In FIG. 11, parts having the same configurations as those of the stators of FIGS. 2 to 9 are denoted by the same reference numerals and description thereof is omitted.

11 has a coil end portion 9 protruding from the upper surface and the lower surface of the iron core piece 101. In the coil end portion 9, no magnetic steel sheet exists, but a magnetic flux 14 is also generated around the coil end portion 9. The magnetic flux 14 at the coil end portion also passes through the electromagnetic steel sheet directly below and contributes to generating a rotating magnetic field. Therefore, the magnetic flux 15 that passes through the bonding band 53 in the radial direction is generated on the upper and lower surfaces of each iron core piece 101.

The stator 130 of the electric motor according to Embodiment 3 of the present invention has an opening portion 27 formed at an end portion in the laminating direction of the electromagnetic steel sheets as compared to the opening portion 7 formed at the center portion of the bonding band 53. Largely formed in the circumferential direction.

Since the opening 27 formed in the end portion of the bonding band 53 is formed larger in the circumferential direction than the opening 7 formed in the central portion, the vortex due to the magnetic flux 14 generated in the coil end portion 9 is formed. Current loss can be reduced.

Further, similarly to the stator 100 of the electric motor according to the first embodiment of the present invention, it is difficult for the magnetic flux to flow in the circumferential direction of the bonding band 53, and eddy current loss can be reduced. Further, even if radial magnetic fluxes are generated, eddy currents perpendicular to the magnetic fluxes hardly flow through the

openings

7 and 27, and the eddy currents can be similarly reduced.

Further, like the stator 100 of the electric motor according to Embodiment 1 of the present invention, the productivity of windings and the like resulting from the shape accuracy is improved, and mechanical vibration and noise of the electric motor are reduced and stabilized. It becomes possible. Therefore, it is possible to obtain an electric motor with high efficiency, low vibration, low noise and high productivity.

The embodiment of the present invention is not limited to the first to third embodiments, and various modifications can be made. For example, the bonding band may have a curved outer peripheral surface. The surface shape of the opening 7 may be various shapes such as a rectangular shape, a circular shape, an elliptical shape, an oval shape, and may have an angle from the stacking direction to the circumferential direction.

1 Insulating member, 2 winding, 3 bonding band, 4 upper end, 5 lower end, 6 outer peripheral surface, 7 opening, 8 non-opening, 9 coil end, 11 outward radial magnetic flux, 12 circumferential magnetic flux, 13 Inward radial magnetic flux, 14 magnetic flux, 15 magnetic flux, 17 opening, 18 non-opening, 22 circumferential eddy current, 23 inward radial eddy current, 27 opening, 33 bonding band, 43 bonding band, 53 bonding band, 100 Stator, 101 Iron core piece, 102 teeth part, 103 core back part, 104 magnetic steel sheet, 105 groove, 110 stator, 111 outward radial magnetic flux, 112 circumferential magnetic flux, 113 inward radial magnetic flux, 120 stator, 122 circumference Direction eddy current, 123 inward radial eddy current, 130 stator, 150 rotor, 151 magnet, 2 1 outward radial flux, 212 circumferential flux, 213 inward radial flux, 222 circumferential eddy currents, 223 inward radial eddy currents, 300 motor.

Claims

An iron core piece composed of a plurality of laminated electromagnetic steel sheets having a core back part and a teeth part protruding from the core back part to the inner peripheral surface;
A bonding band for fastening the plurality of electromagnetic steel sheets in the stacking direction,
An electric motor stator in which an opening is provided on an outer peripheral surface of the joining band.
The motor stator according to claim 1, wherein a plurality of the openings are arranged in the stacking direction.
The electric motor stator according to claim 1 or 2, wherein a plurality of the openings are arranged in a circumferential direction.
The motor stator according to claim 3, wherein the opening and the non-opening are displaced in the circumferential direction.
The motor stator according to any one of claims 1 to 4, wherein the opening has a shape that is longer in the stacking direction than in a circumferential width.
The motor stator according to any one of claims 1 to 4, wherein the opening has a shape longer in a circumferential direction than a width in the stacking direction.
The motor fixing according to any one of claims 2 to 6, wherein the opening is formed such that an opening formed in an end portion is larger in a circumferential direction than an opening formed in a central portion in the stacking direction. Child.
The motor stator according to any one of claims 1 to 7, wherein the joining band is made of austenitic stainless steel or nonferrous metal having a relative permeability of 1.01 or less.
The motor stator according to any one of claims 1 to 7, wherein the joining band is made of engineering plastic.
An electric motor comprising the stator according to any one of claims 1 to 9.