Patent Application
20230318386
The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2022-054233, filed on Mar. 29, 2022, the entire contents of which are hereby incorporated herein by reference.
The present disclosure relates to a stator and a wedge insertion device.
Conventionally, a wedge insertion device that inserts a wedge between a coil inserted into a slot of a stator core and the stator core in order to insulate the coil from the stator core is known. For example, a known coil insertion device includes a wedge guide forming a guide groove for inserting a wedge. However, when the wedge is pushed up and inserted into the slot using the known coil insertion device, the wedge may be buckled.
A stator according to an example embodiment of the present disclosure includes a stator core including teeth arranged in a circumferential direction and slots between the teeth and penetrating in an axial direction, and a wedge located radially inward of the slot. The stator core includes a groove portion at an end of each of the teeth in a circumferential direction. A portion of the wedge is located in the groove portion.
A wedge insertion device according to an example embodiment of the present disclosure inserts a wedge located between a coil inserted into a slot from one side to another side in an axial direction and a stator core, the slot penetrating a stator core in an axial direction thereof. The stator core includes a groove portion at an end of each of the teeth in a circumferential direction. The wedge insertion device includes a wedge guide that is on one side in an axial direction of the stator core, extends in the axial direction, and guides the wedge to the groove portion. An end surface on another side in the axial direction of the wedge guide has a shape corresponding to the groove portion.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
Hereinafter, example embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, an identical or corresponding component is denoted by an identical reference sign, and the description will not be repeated.
In the following description, a direction in which the central axis of a stator 1 extends, that is, a penetrating direction of a slot 24 is referred to as an “axial direction”. One side along the axial direction is referred to as the lower side, and the other side is referred to as the upper side. The upward and downward direction is for use in specifying the positional relationship, and does not limit the actual direction. That is, a downward direction does not necessarily mean the direction of gravity. The axial direction is not particularly limited, and includes a vertical direction, a horizontal direction, a direction intersecting these directions, and the like.
Additionally, a direction orthogonal to the central axis of the stator 1 is referred to as “radial direction”. Moreover, a direction along an arc centered on the central axis of the stator 1 is referred to as “circumferential direction”.
In addition, in the drawings used in the following description, a characteristic portion may be enlarged for the purpose of emphasizing the characteristic portion. Therefore, the dimensions and ratios of respective components are not necessarily the same as actual ones. Additionally, for the same purpose, less characteristic portions may be omitted from the drawings.
As illustrated in
The stator core 20 is formed in a hollow columnar shape. The stator core 20 is formed by laminating thin silicon steel plates. The stator core 20 includes a core back 21, a plurality of teeth 22, and a plurality of umbrella 23.
The core back 21 is annular. The core back 21 of the present example embodiment includes one member. That is, the core back 21 is configured by one component instead of a plurality of components that can be divided in the circumferential direction.
The plurality of teeth 22 extend from the core back 21 in the radial direction. The plurality of teeth 22 are located in the circumferential direction.
Specifically, the teeth 22 extend radially inward from the core back 21. The teeth 22 are disposed at equal intervals in the circumferential direction in the inner end of the core back 21 in the radial direction. Note that the circumferential width of the teeth 22 of the present example embodiment is constant, but may not be constant.
The slot 24 is provided between the teeth 22 adjacent to each other in the circumferential direction. The slot 24 is a gap in the circumferential direction.
The plurality of slots 24 penetrates in the axial direction. The circumferential width of the slot 24 increases radially outward. The circumferential width of the slot 24 of the present example embodiment gradually increases radially outward.
The slot 24 has a slot open 25 located at the inner end in the radial direction. The slot open 25 is smaller than the circumferential width of the space accommodating the coil 10 in the slot 24.
The plurality of umbrella 23 is located on both sides of the slot 24 in the circumferential direction and protrudes in the circumferential direction. Specifically, the plurality of umbrella 23 are connected to the inner end of each of the teeth 22 in the radial direction and extends to both sides in the circumferential direction. That is, the circumferential width of the umbrella 23 is larger than the circumferential width of the inner end of the teeth 22 in the radial direction. The plurality of umbrella 23 are disposed at equal intervals in the circumferential direction. When used in a motor, the plurality of umbrella 23 face the rotor.
As illustrated in
The wedge 30 is disposed radially inward of the slot 24. Specifically, the wedge 30 is located between the coil 10 inserted into the slot 24 and the stator core 20. In
The wedge 30 contacts the umbrella 23. As a result, the wedge 30 can be easily inserted into the slot 24.
The wedge 30 of the present example embodiment has a U-shape as viewed in the axial direction. Specifically, the wedge 30 includes a first shape portion 31, two second shape portions 32, and a bent portion 33.
The first shape portion 31 extends in the circumferential direction. The first shape portion 31 is linear as viewed in the axial direction. As a result, the wedge 30 can be easily inserted into the slot 24.
The two second shape portions 32 extend radially outward. The second shape portion 32 is linear as viewed in the axial direction.
The bent portion 33 connects both ends of the first shape portion 31 and the inner end of the second shape portion 32 in the radial direction. The bent portion 33 is a bend corner of the wedge 30, and may be curved or sharp.
The first shape portion 31, the second shape portion 32, and the bent portion 33 may be formed of one member, or different members may be connected to each other.
The insulating paper 40 covers the coil 10 inserted into the slot 24. The insulating paper 40 is disposed along the teeth 22 that define a space excluding the inner side of the slot 24 in the radial direction. The insulating paper 40 of the present example embodiment has a U shape. Specifically, the insulating paper 40 includes a circumferential portion 41 extending in the circumferential direction and two radial portions 42 extending radially inward from both ends of the circumferential portion 41. In
Here, the groove portion 26 of the stator core 20 will be described mainly with reference to
A part of the wedge 30 is located in the groove portion 26. Therefore, at the time of manufacturing the stator 1, a part of the wedge 30 can be held by the groove portion 26 and inserted. Therefore, buckling of the wedge 30 can be suppressed.
The groove portion 26 is a space for accommodating a part of the wedge 30. The groove portion 26 is a recess provided at the end of the teeth in the circumferential direction.
The groove portion 26 is formed of a segment. The segment is a part of the teeth 22 and defines the groove portion 26.
The groove portion 26 is located at the inner end of the stator core 20 in the radial direction. Therefore, since the wedge 30 can be disposed at the inner end in the radial direction, the space factor of the coil 10 can be improved.
In addition, the groove portion 26 is located on the outer side of one slot 24 in the circumferential direction. The groove portion 26 is located on the outer side in the circumferential direction of the umbrella 23 protruding from the teeth 22.
The groove portion 26 of the present example embodiment has a shape recessed radially outward. As a result, a part of the wedge 30 can be easily located in the groove portion 26. In
As viewed in the axial direction, a circumferential width W26 of the groove portion 26 is smaller than a circumferential width W25 of the slot open 25. Accordingly, it is possible to suppress the coil 10 from being located in the groove portion 26.
As viewed in the axial direction, the circumferential length (circumferential width W) of the groove portion 26 is smaller than a radial length L26 of the groove portion 26. As a result, deterioration of magnetic characteristics due to the groove portion 26 can be suppressed.
The circumferential width W26 of the groove portion 26 is larger than the circumferential width of the second shape portion 32 of the wedge 30. The radial length L26 of the groove portion 26 is longer than the radial length of the second shape portion 32 of the wedge 30. However, from the viewpoint of magnetic characteristics, the groove portion 26 is preferably small. Therefore, the circumferential width W26 of the groove portion 26 is more than 1 time and preferably 1.2 times or less the circumferential width of the second shape portion 32 of the wedge 30. The radial length L26 of the groove portion 26 is more than 1 time and preferably 1.2 times or less the radial length of the second shape portion 32 of the wedge 30.
The groove portion 26 is continuous with the slot 24. The wedge 30 is accommodated in the groove portion 26 and the slot 24. Here, a part of the wedge 30 is located in the groove portion 26 and the rest of the wedge 30 is located in the slot 24.
Specifically, the first shape portion 31 of the wedge 30 is located in the slot 24. Both ends of the first shape portion 31 in the circumferential direction may be located in the slot 24, or may be located in the groove portion 26. The second shape portion 32 of the wedge 30 is located in the groove portion 26. Further, the bent portion 33 of the wedge 30 is located in the groove portion 26. Accordingly, separation of the wedge 30 from the groove portion 26 can be suppressed.
The bent portion 33 may not be in contact with the groove portion 26, but is in contact with the groove portion in the present example embodiment. The bent portion 33 may not be in contact with the side surface of the slot 24, but is in contact with the side surface in the present example embodiment. Note that
A wedge insertion device 200 will be described with reference to
As illustrated in
The wedge insertion device 200 includes the wedge guide 210. The wedge guide 210 guides the wedge 30 to the slot 24. The wedge guide 210 is located on one side of the stator core 20 in the axial direction and extends in the axial direction.
The wedge guide 210 of the present example embodiment guides the wedge 30 to the groove portion 26. The end surface in the axial direction of the wedge guide 210 in the axial direction has a shape corresponding to the groove portion 26. As a result, the wedge guided by the wedge guide can be easily inserted into the groove portion.
Specifically, the end surface in the axial direction of the wedge guide 210 in the axial direction has a shape that guides a part of the wedge 30 to the groove portion 26 and guides the rest of the wedge 30 to the slot 24.
The wedge insertion device 200 further includes an insertion member that inserts the wedge 30 into the slot 24. The wedge insertion device 200 of the present example embodiment further includes a wedge pusher (not illustrated) as an insertion member.
A method for manufacturing the stator 1 of the present example embodiment will be described with reference to
In the present example embodiment, the stator 1 is manufactured by inserting the coil 10 into the slot 24 by the coil insertion device 100 and inserting the wedge 30 into the slot 24 by the wedge insertion device 200 described above.
First, as illustrated in
As illustrated in
In the present example embodiment, before the coil 10 described later is inserted into the slot 24, the insulating paper 40 is located in the slot 24.
Next, the coil 10 is inserted into the slot 24 (step S3). This step (S3) is performed as follows, for example.
Specifically, as illustrated in
In addition, the wedge 30 is located in at least one slot 24 and one groove portion 26 between the teeth 22 adjacent in the circumferential direction (step S4). In step S5, as illustrated in
By performing the above steps (steps S1 to S4), the stator 1 illustrated in
Next, operations and effects of the stator 1 of the present example embodiment will be described in comparison with a stator 2 of a comparative example of
As illustrated in
On the other hand, as illustrated in
Further, since the groove portion 26 can hold a part of the wedge 30, insertion and arrangement of the wedge 30 into the slot 24 are easy.
The stator of a second example embodiment illustrated in
The groove portion 26 of the first example embodiment illustrated in
The stator of a third example embodiment illustrated in
The groove portion 26 of the first example embodiment illustrated in
The stator of a fourth example embodiment illustrated in
The groove portion 26 of the first example embodiment illustrated in
Specifically, the teeth 22 of the present example embodiment have the protrusion 22a that defines the groove portion 26 and extends in the circumferential direction. As a result, deterioration of magnetic characteristics due to the groove portion 26 can be suppressed.
In
A circumferential width W22a of the protrusion 22a is equal to or less than a circumferential width W23 protruding from the teeth 22 in the umbrella 23, and is preferably smaller than the circumferential width W23. In this case, it is possible to suppress the protrusion 22a from hindering the insertion of the coil 10 into the slot 24.
The protrusion 22a may be located in the entire axial direction of the stator core 20, but is preferably located only at the end on one side of the stator core 20 in the axial direction. That is, the protrusion 22a is preferably not disposed at the other end of the stator core 20 in the axial direction. In this case, the groove portion 26 can hold the wedge 30 at the one-side end in the axial direction and prevent the insertion of the coil 10 from being hindered at portions other than the one-side end in the axial direction.
The shape of the groove portion 26 of the present disclosure is not limited to the shape of the groove portion 26 of the first to fourth example embodiments described above as long as a part of the wedge 30 is disposed.
In the first to fourth example embodiments described above, the stator core 20 has the groove portion 26 having the same shape, but the present disclosure is not limited thereto. The stator core of the present disclosure may have two or more kinds of groove portions of the first to fourth example embodiments.
In the above-described example embodiment, as illustrated in
In the above-described example embodiment, the method for inserting one coil 10 into two slots 24 has been described as an example. A plurality of coils 10 may be simultaneously inserted into four or more slots 24.
The example embodiments disclosed herein should be considered as an example in all points and not restrictive. The scope of the present disclosure is shown not by the example embodiments described above but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the scope of the claims are included.
Features of the above-described example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.
While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-054233 | Mar 2022 | JP | national |
