WO2023170903A1

WO2023170903A1 - Motor

Info

Publication number: WO2023170903A1
Application number: PCT/JP2022/010825
Authority: WO
Inventors: 健次加藤
Original assignee: 三菱電機株式会社
Priority date: 2022-03-11
Filing date: 2022-03-11
Publication date: 2023-09-14
Also published as: JPWO2023170903A1

Abstract

In a stator core of the present invention, electromagnetic steel sheets that each have a pair of recesses of differing lengths in the circumferential direction are stacked in the axial direction, and are provided such that the orientations of the electromagnetic steel sheets in the axial direction are reversed. Thus, obtained is a motor in which it is possible to reduce gaps that occur on either end in the axial direction of the stator core and to suppress winding bulging.　A motor (1) comprises a columnar rotor (2) in which a magnet (21) is provided, and a stator (3) in which a plurality of stator cores (31) are disposed in a ring shape on the outer circumferential side of the rotor (2), wherein in each stator core (31), electromagnetic steel sheets (34) that each have a pair of recesses (8) of differing lengths in the circumferential direction are stacked in the axial direction and are provided such that the orientations of the electromagnetic steel sheets (34) in the axial direction are reversed, and a coil (32) is wound in the pairs of recesses (8).

Description

motor

The present disclosure relates to a motor.

The coil of the motor is formed by winding a winding wire around the teeth of a stator core, which is a magnetic core, through an insulator, which is an insulator. Furthermore, conventional stator cores generally have a shape that is long in the axial direction and short in the circumferential direction.

Therefore, when winding the winding around the teeth of the stator core, a bulge occurs. Therefore, as a technology to reduce the gap between the winding and the stator core due to the winding bulge, for example, a magnetic generator is equipped with a laminated core whose width in the rotor rotation direction gradually narrows from the center to both ends in the rotor axial direction. has been disclosed (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2004-135382

The above generator reduces the gap when the winding bulge occurs near the center of the laminated core in the axial direction. On the other hand, since the width of the laminated core in the rotor rotational direction becomes narrower from the central part in the axial direction toward both ends, gaps are created at both ends in the axial direction.

The present disclosure has been made in order to solve the above-mentioned problems, and provides a motor that can reduce the voids that occur at both ends of the laminated core in the axial direction when winding the winding wire, and suppress winding bulge. The purpose is to obtain.

A motor according to the present disclosure includes a cylindrical rotor provided with magnets and electromagnetic steel plates having a pair of recesses having different lengths in the circumferential direction, stacked in the axial direction, and the direction of the electromagnetic steel plates is reversed in the axial direction. The rotor is provided with a stator core having a winding wound around a pair of recesses, and a plurality of stators arranged annularly on the outer diameter side of the rotor.

According to the motor of the present disclosure, the stator core is provided by laminating in the axial direction electromagnetic steel plates having a pair of recesses having different lengths in the circumferential direction, and reversing the direction of the electromagnetic steel plates in the axial direction. This has the effect of reducing the gap generated near the center of the stator core in the axial direction and also reducing the gap generated at both ends, thereby suppressing curling and swelling.

1 is a schematic diagram of a motor according to Embodiment 1. FIG. 2 is a diagram illustrating a part of cross section AA in FIG. 1. FIG. 3 is a partially enlarged view of FIG. 2. FIG. It is an external view of an electromagnetic steel sheet. FIG. 4 is a diagram showing cross section B in FIG. 3 of the stator core of the motor according to the first embodiment. FIG. 4 is a diagram showing cross section B in FIG. 3 of the stator core of the motor according to the second embodiment.

Hereinafter, embodiments will be described in detail based on the drawings. Note that the embodiment described below is an example. Moreover, each embodiment can be executed in combination as appropriate.

Further, as shown in the drawings, the axial direction and circumferential direction will be defined and explained. The axial direction is the direction in which the shaft extends. The radial direction is the radial direction of the shaft. The circumferential direction is the direction in which the shaft rotates.

Embodiment 1.
FIG. 1 is a schematic diagram of a motor according to a first embodiment. FIG. 2 is a diagram showing a part of the cross section AA in FIG. 1. FIG. 3 is an enlarged view of a portion of the stator core of FIG. 2. As shown in FIG. FIG. 4 is an external view of the electrical steel sheet. FIG. 5 is a diagram showing cross section B of FIG. 3 in the stator core of the motor according to the first embodiment.

The motor 1 shown in FIG. 1 includes a rotor 2, a stator 3, a frame 4, an encoder 5, and a bracket 6.

The following will explain using FIGS. 1 and 2. The rotor 2 has a cylindrical shape and includes a magnet 21 and a shaft 22. As shown in FIG. 2, a plurality of magnets 21 are provided on the outer diameter side of the shaft 22. Note that the example shown in FIG. 2 is an example, and the arrangement position and arrangement method of the magnet 21 are not particularly limited. For example, it may be fixed to the outer peripheral surface of the shaft 22 using an adhesive or the like. Further, it may be embedded in the shaft 22 so as to face the stator 3 on the outer diameter side of the shaft 22.

The shaft 22 is provided to pass through the stator 3 and the bracket 6, and is rotatable in the circumferential direction. The brackets 6 are provided at both ends of the stator 3 in the axial direction so as to closely support the frame 4 without inhibiting rotation of the shaft 22. Note that, as shown in FIG. 1, the brackets 6 provided at both ends of the frame 4 include a bracket 6a and a bracket 6b. The bracket 6a and the bracket 6b are provided on opposite sides of the stator 3.

The encoder 5 is provided at the end of the bracket 6b opposite to the frame 4 in the axial direction. The encoder 5 includes a sensor and measures the rotation speed and rotation angle of the rotor 2. Note that the sensor installed in the encoder 5 may be, for example, an acceleration sensor, but is not limited thereto.

The frame 4 has a cylindrical shape, and is provided in close contact with the outer circumferential surface of the stator 3 so that its inner circumferential surface holds the outer circumferential surface of the stator 3. Further, like the stator 3, the frame 4 is provided with a bracket 6a and a bracket 6b in close contact with each other at both ends in the axial direction.

The stator 3 has a cylindrical shape in which a plurality of stator cores 31 are arranged annularly on the outer diameter side of the rotor 2, and is provided so as to cover the outer peripheral surface of the rotor 2. Note that the rotor 2, stator 3, and frame 4 are concentric.

Next, the stator core 31 will be explained using FIGS. 3 to 5. A plurality of stator cores 31 arranged in a circular shape on the outer diameter side of the rotor 2 include a winding 32 , an insulating paper 33 , and an insulator 7 .

As shown in FIG. 3, the stator core 31 includes teeth portions 35 around which the winding 32 is wound with an insulating paper 33 interposed therebetween. The insulating paper 33 is provided so as to be sandwiched between the teeth 35 and the winding 32, and has the role of preventing the current flowing through the winding 32 from flowing toward the teeth 35. Note that the teeth portions 35 around which the winding wire 32 is wound are provided with asymmetrical distances from the circumferential center of the stator core 31.

Further, the winding 32 is provided so as to be wound around the teeth portion 35 of the stator core 31. Although the material of the winding 32 is not particularly limited, it is preferable to use copper, for example. Further, the pair of insulators 7 are provided at both ends of the stator core 31 in the axial direction.

The stator core 31 is constructed by laminating electromagnetic steel plates 34 shown in FIG. 4 in the axial direction. The electromagnetic steel plate 34 has a pair of recesses 8 having different lengths in the circumferential direction. That is, the first recess 81 has a shorter length in the circumferential direction than the second recess 82, and the first recess 81 and the second recess 82 are provided at asymmetrical distances from the center of the electromagnetic steel sheet 34 in the circumferential direction. ing. Note that in this embodiment, the length of the recess 8 represents the depth of the recess 8 in the circumferential direction.

Furthermore, the stator core 31 is constructed by stacking the electromagnetic steel plates 34 with their directions reversed in the axial direction. For example, assuming that the electromagnetic steel sheet 34 shown in FIG. 4 is the front side, "inversion" here refers to turning the front and back sides upside down. In other words, the stator core 31 is constructed by reversing the direction of the electromagnetic steel plates 34, that is, turning the electromagnetic steel plates 34 upside down, during the stacking process when the electromagnetic steel plates 34 are stacked in the axial direction. This will be explained specifically using FIG. 5.

FIG. 5 shows cross section B of FIG. 3 at the tooth portion 35. The arrow indicates the direction in which the winding 32 is wound. As shown in FIG. 5, the teeth portion 35 of the stator core 31 is provided by laminating electromagnetic steel plates 34 in the axial direction and reversing the direction of the electromagnetic steel plates 34 in the axial direction. That is, the stator core 31 is configured such that teeth portions 35 having the same width are shifted in the circumferential direction.

Although the position and number of times of reversal of the direction of the electromagnetic steel sheets 34 are not limited, it is preferable to reverse the direction of the electromagnetic steel sheets 34 at the axial center of the stator core 31 and stack them as shown in FIG. In this way, the stator core 31 is provided by stacking the electromagnetic steel sheets 34 with their directions reversed at the center in the axial direction, so that only one cutting die shape is required to create the electromagnetic steel sheets 34. . Therefore, there is no need to prepare electromagnetic steel sheets 34 having different shapes, and manufacturing costs can be reduced.

Further, when winding the winding 32 around the teeth portion 35, the position of the winding bulge differs depending on the direction in which the winding 32 is wound. Specifically, as shown in FIG. 5, when the winding 32 is wound in the circumferential direction from the second recess 82 to the first recess 81, that is, counterclockwise, a winding bulge is created on the first recess 81 side. As a result, the gap between the winding 32 and the teeth portion 35 of the stator core 31 becomes larger. Similarly, when the winding wire 32 is wound in the opposite direction, a bulge is generated on the second recess 82 side shown in FIG.

Therefore, in the stator core 31, the direction of the electromagnetic steel plate 34 is reversed in the axial direction so that the first recess 81 is in the front and the second recess 82 is in the rear in the direction in which the winding 32 is wound in the circumferential direction. Constructed by stacking. In other words, the stator core 31 is configured such that the first recess 81 located at the front in the direction in which the winding 32 is wound in the circumferential direction is shorter than the second recess 82 located at the rear. With this configuration, it is possible to reduce the gap caused by the winding bulge that occurs when the winding wire 32 is wound.

Although FIG. 5 shows an example in which the winding 32 is wound counterclockwise, similarly, when winding the winding 32 clockwise, a length longer than the second recess 82 is placed forward in the circumferential direction. The stator core 31 is provided by stacking the electromagnetic steel plates 34 with their orientation reversed in the axial direction so that the first recess 81 has a short length and the second recess 82 exists at the rear.

Next, the operation of the motor 1 will be explained. The rotor 2 is rotated by the current input to the winding 32, and power is transmitted from the shaft 22 to the outside. At this time, the encoder 5 detects the rotation speed and rotation angle of the rotor 2, and sends a signal to a control device (not shown).

Furthermore, as current flows through the winding 32, copper loss occurs in the winding 32, and the generated loss becomes heat and moves inside the motor 1, raising the temperature of each part. The heat that has passed through each part is radiated to the outside of the motor 1 from the frame 4, shaft 22, brackets 6a, 6b, etc. by heat conduction, convection, radiation, etc. Note that the method of cooling the frame 4 is not particularly limited and may be either air cooling or liquid cooling.

At this time, heat generated due to copper loss in the winding 32 is transmitted to the stator core 31 via the insulating paper 33 and the insulator 7. On the other hand, in addition to the insulating paper 33 and the insulator 7, there is an air gap, that is, a void, between the winding 32 and the stator core 31. Since the thermal conductivity of air is lower than that of the insulating paper 33 and the insulator 7, the larger the gap, the greater the thermal resistance between the winding 32 and the stator core 31, and the temperature of the winding 32 increases.

However, the motor 1 of the present embodiment is provided by laminating the electromagnetic steel plates 34 having a pair of recesses 8 having different lengths in the circumferential direction in the axial direction, and reversing the orientation of the electromagnetic steel plates 34 in the axial direction. It constitutes a stator core 31. With this configuration, it is possible to reduce the gap near the center in the axial direction that is generated due to the curling and bulging, and also to reduce the gaps that occur at both ends in the axial direction. This reduces the thermal resistance between the stator core 31 and the winding 32, reduces the temperature of the winding 32, and improves the energy efficiency of the motor 1.

Furthermore, by configuring the stator core 31 by stacking the electromagnetic steel plates 34 with their directions reversed at the center in the axial direction, it is not necessary to create electromagnetic steel plates 34 with different shapes, and manufacturing costs can be reduced.

Embodiment 2.
This embodiment will be explained using FIG. 6. FIG. 6 is a diagram showing cross section B in FIG. 3 of the stator core of the motor according to this embodiment.

In Embodiment 1, a motor is provided with a stator core in which electromagnetic steel plates having a pair of recesses having different circumferential lengths are laminated in the axial direction, and the orientation of the electromagnetic steel plates is reversed in the axial direction. Indicated. Embodiment 2 shows a motor including an insulator in which a winding portion that is wound together with a stator core protrudes in a direction opposite to the stator core. The other configurations are the same as those in Embodiment 1, and the same components as in Embodiment 1 are given the same numbers and their explanations will be omitted.

As shown in FIG. 6, in the pair of insulators 71, a winding portion 74 that is wound around the winding 32 together with the stator core 31 via the insulating paper 33 has a chevron-shaped portion that protrudes in the opposite direction to the stator core 31. It has the shape of Although FIG. 6 shows an example in which the winding portion 74 has a mountain-shaped shape, the present invention is not limited to this, and any shape may be used as long as it protrudes in the opposite direction to the stator core 31.

Further, the winding portions 74 of the pair of insulators 71 having a chevron-shaped shape are provided closer to the first recess 81 than the center in the circumferential direction of the top portion 72 . Note that the top portion 72 is a protruding portion of the winding portion 74 that protrudes most in the direction opposite to the stator core 31.

This will be explained using FIG. 6. The direction of the arrow shown in FIG. 6 indicates the direction in which the winding wire 32 is wound. When winding the winding 32 to the left, the winding bulge tends to occur on the first recess 81 side shown in FIG. It is provided on the first recess 81 side. Similarly, when the winding 32 is wound rightward, the winding bulge tends to occur on the second recess 82 side shown in FIG. It is provided closer to the second recess 82 shown in FIG. That is, the top portion 72 of the winding portion 74 is provided on the side of the first recess 81 located forward of the center in the circumferential direction of the winding portion 74 in the direction in which the winding 32 is wound.

Since the top portion 72 of the winding portion 74 is provided closer to the first recess 81 than the center in the circumferential direction, the winding 32 is provided closer to the first recess 81 than the center in the circumferential direction. It is possible to reduce the gap between the stator core 31 and the winding 32 due to the winding bulge that occurs when the winding is wound.

1, 11 motor, 2 rotor, 21 magnet, 22 shaft, 3 stator, 31 stator core, 32 winding, 33 insulating paper, 34 electromagnetic steel plate, 35 teeth part, 4 frame, 5 encoder, 6, 6a, 6b bracket, 7, 71 insulator, 72 top, 73, 74 winding part, 8 recess, 81 first recess, 82 second recess

Claims

A cylindrical rotor equipped with magnets,
Electromagnetic steel sheets having a pair of recesses having different lengths in the circumferential direction are laminated in the axial direction, the orientation of the electromagnetic steel sheets is reversed in the axial direction, and a winding wire is wound around the pair of recesses. a stator in which a plurality of stator cores are arranged annularly on the outer diameter side of the rotor;
A motor equipped with
The motor according to claim 1, wherein the stator core has the electromagnetic steel plate reversed in direction at the center in the axial direction.
The pair of recesses provided in the stator core have a first recess and a second recess,
According to claim 1 or 2, the length of the first recess located at the front in the direction in which the winding is wound in the circumferential direction is shorter than that of the second recess located at the rear. Motor listed.
The pair of insulators provided at the ends of the stator core in the axial direction have a winding portion wound around the winding together with the stator core protruding in a direction opposite to the stator core. The motor according to any one of claims 1 to 3, characterized in that:
The winding portion has a chevron-shaped shape protruding in a direction opposite to the stator core, and a top portion is provided closer to the first recess than the center in the circumferential direction. 4. The motor according to item 4.