This application is based on and claims the benefit of priority from Japanese Patent Application No. 2018-026665, filed on 19 Feb. 2018, the content of which is incorporated herein by reference.
The present invention relates to a coil for a rotary electric machine. Specifically, the present invention relates to a coil for a rotary electric machine constituted by an overlapping coil-type wave winding coil.
A wave winding coil is known in the related art as a coil mounted in slots of a stator core of a rotary electric machine such as an electric motor and a generator. The wave winding coil is configured in a wave shape by a coil wire that has slot accommodating portions accommodated in the slots and a coil end portion interconnecting, in a chevron shape, the end portions of the slot accommodating portions which are next to each other.
Regarding this wave winding coil, weaving- and overlapping coil-type disposition patterns are known as disposition patterns accommodated in the adjacent slots. In the weaving-type disposition pattern, the slot accommodating portions of the coil wire are alternately disposed in a first layer and a second layer. The overlapping coil-type disposition pattern is a pattern in which the slot accommodating portions of the coil wire are disposed in first layers and second layers (see, for example, Patent Documents 1 and 2). Of them, the overlapping coil-type pattern, in which the slot accommodating portions of the coil wire are disposed in the same layer in the slots, does not require weaving of a plurality of the coil wires, and thus is advantageous in that wave winding coil manufacturing can be expedited, damage to the coil wire can be reduced, and the like.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2004-282996
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2016-92997
In a case where a coil for a rotary electric machine is made of an overlapping coil-type wave winding coil and the wave winding coil of each layer accommodated in the slot is configured in a substantially spiral shape by being connected for circumferential connection, the total length of the wave winding coil before molding in the substantially spiral shape increases, which results in an increase in the size of a wave winding coil transport device and an increase in transport distance. Then, a problem arises in the form of time-consuming transport.
In addition, in the overlapping coil-type wave winding coil according to the related art, the stacked coil wires are simply layered without being integrated by weaving or the like, and thus a problem arises as the coil wires are scattered during transport.
A step of molding the overlapping coil-type wave winding coil in a substantially spiral shape includes, for example, a manufacturing method for sequential winding from the wave winding coil that constitutes the innermost layer. Still, the overlapping coil-type wave winding coil according to the related art lacks integration based on coil wire intertwining unlike a woven coil-type coil, and thus has a problem in that each coil wire is scattered or deformed by tension during winding.
In this regard, an object of the present invention is to provide a coil for a rotary electric machine based on an overlapping coil-type wave winding coil, which is an overlapping coil-type wave winding coil yet facilitates coil handling including transport by means of a compact pre-annular molding total length and allows each coil wire to be easily incorporated into a slot.
(1) A coil for a rotary electric machine according to the present invention is a coil for a rotary electric machine (such as a coil 100 to be described later) mounted in a plurality of slots (such as slots 201 to be described later) of a stator core (such as a stator core 200 to be described later) having the slots in a circumferential direction. An overlapping coil-type wave winding coil constituted by a coil wire (such as a coil wire 1 to be described later) having a plurality of slot accommodating portions (such as slot accommodating portions 11 to be described later) accommodated in the slots and a plurality of coil end portions (such as coil end portions 12 to be described later) interconnecting the slot accommodating portions next to each other outside the slots in an axial direction of the stator core constitutes the coil. At least two layers (such as layers 10 to 60 to be described later) of the coil wire are connected by a continuous wire-based connecting portion (such as a connecting portion 15 to be described later), folded back in the connecting portion, and stacked. A stacking configuration in which the overlapping coil-type wave winding coil is folded back and stacked results from (1), and thus the total length of the wave winding coil before annular molding can be compact. As a result, the size of a transport device transporting the coil can be reduced, handling of the coil can be facilitated, and each coil wire can be easily incorporated into the slot.
(2) Preferably, in the coil for a rotary electric machine according to (1), the layers are constituted by a plurality of the coil wires being sequentially stacked, and a stacking order of the plurality of coil wires between the layers next to each other is reversed and the plurality of coil wires are folded back with the stacking order maintained in the connecting portion. As a result of (2), the wave winding coil stacked in the plurality of layers can be easily manufactured by sequential insertion of each previously folded coil wire from a folding direction.
(3) Preferably, in the coil for a rotary electric machine according to (1) or (2), a top portion (such as a top portion 122 to be described later) of the coil end portion of the coil wire constituting the layer disposed on a radial-direction outside of the stator core is higher in the axial direction of the stator core than a top portion of the coil end portion of the coil wire constituting the layer disposed on a radial-direction inside of the stator core. As a result of (3), the coil end heights of the layer disposed on the radial-direction outside of the stator core and the layer disposed on the radial-direction inside of the stator core can be easily aligned after annular molding even with the intervals of the slot accommodating portions before the annular molding evenly aligned.
(4) Preferably, in the coil for a rotary electric machine according to any one of (1) to (3), an interval between the adjacent slot accommodating portions of the coil wire is shorter in the layer disposed on the radial-direction inside of the stator core than in the layer disposed on the radial-direction outside of the stator core. As a result of (4), the circumferential lengths of the coil wire disposed on the radial-direction outside of the stator core and the coil wire disposed on the radial-direction inside of the stator core can be easily aligned.
(5) Preferably, in the coil for a rotary electric machine according to (4), the interval of the slot accommodating portion in a vicinity of the folded part of the coil wire is smaller than the interval of the slot accommodating portion at a part other than the vicinity of the folded part of the coil wire. As a result of (5), in the folded coil wire, the circumferential lengths of the coil wire disposed on the outer peripheral side of the stator core and the coil wire disposed on the inner peripheral side of the stator core can be easily aligned in a state where the central position of each layer is aligned.
(6) Preferably, in the coil for a rotary electric machine according to any one of (1) to (5), each layer of the coil wire is stacked by shifting by a plurality of slots in the same direction along the circumferential direction of the stator core. As a result of (6), a stepwise end portion shape is achieved without the end portions resulting in a complicated structure when the manufactured coil is annularly rounded, and thus annular formation can be performed by simple inter-end portion stacking.
(7) Preferably, in the coil for a rotary electric machine according to any one of (1) to (6), the coil wire over each layer (such as the layers 10 to 60 to be described later) is a continuous wire. As a result of (7), the entire coil can be manufactured with one continuous wire, and thus the number of joints can be minimized with no limitation and manufacturing processes can be simplified.
(8) Preferably, in the coil for a rotary electric machine according to any one of (1) to (7), wires (such as wires 1a to 1c to be described later) divided in the circumferential direction of the stator core constitute the coil wire. As a result of (8), the coil can be easily deformed when the coil is deformed in the circumferential direction so that the manufactured coil is inserted into the slot from the inner diameter side of the stator core.
With the present invention, it is possible to provide a coil for a rotary electric machine based on an overlapping coil-type wave winding coil, which is an overlapping coil-type wave winding coil yet facilitates wave winding coil handling including transport by means of a compact pre-annular molding total length and allows each coil wire to be easily incorporated into a slot.
Hereinafter, an embodiment of the present invention will be described in detail with reference to accompanying drawings.
Next, the coil 100 for a rotary electric machine (hereinafter, simply referred to as the coil 100) mounted in the stator core 200 will be described.
As illustrated in
Here, the coil wire 1 constituting the coil 100 will be described.
The slot accommodating portion 11 is a part accommodated in the slot 201 of the stator core 200 and is formed in a substantially straight shape so as to be along the axial direction of the stator core 200 (D1 direction). The coil end portion 12 is a part protruding outwards in the axial direction (D1 direction) from upper and lower end surfaces 200a (see
The coil wire 1 has lead portions 13 and 14 in both end portions of the coil 100, respectively. The lead portions 13 and 14 are connected to the upper end portion of the slot accommodating portion 11 disposed in the end portion of the coil wire 1, extend obliquely upwards from the slot accommodating portion 11, and have end portions bent so as to rise along the axial direction of the stator core 200 (D1 direction).
The coil 100 of the present embodiment is constituted by the similarly molded coil wires 1 being sequentially stacked side by side to be misaligned by a predetermined pitch in the circumferential direction of the stator core 200 (D2 direction) such that the slot accommodating portions 11 are parallel. Illustrated in
Here, the configuration of the coil wire 1 will be further described. Each chevron-shaped coil end portion 12 of the coil wire 1 has a bent portion 121 bent and connected to each slot accommodating portion 11 and a chevron-shaped top portion 122 of the coil end portion 12. As illustrated in
Specifically, the coil end portion 12 connected to the lower end portion of the slot accommodating portion 11 is displaced by W/2 (+W/2) to the radial-direction outside of the stator core 200 (D31 direction side illustrated in
Although not illustrated in
Illustrated in
By the six coil wires 1 being folded back in a zigzag manner and stacked in the connecting portion 15 in this manner, the slot accommodating portions 11 of the respective layers 10 to 60 are stacked in up to six layers in the radial direction. In the connecting portion 15, the radial displacement amount of the coil wire 1 is adjusted such that the slot accommodating portions 11 of the respective layers 10 to 60 are stacked with the slot accommodating portions 11 radially misaligned.
To be specific with respect to
The obtained coil 100 is inserted into the center of the stator core 200 after rounded in an annular shape, and then is mounted in the stator core 200 by each slot 201 accommodating the slot accommodating portion 11 equivalent to six layers. The part of the slot accommodating portion 11 of the coil wire 1 equivalent to one layer has only the width W of one coil wire 1, and thus the width dimension of the part of the slot accommodating portion 11 (dimension along the radial direction of the stator core 200) does not have to exceed the width of six coil wires 1 (W×6) as illustrated in
As described above, the coil 100 has a configuration in which the long coil wire 1 molded in a predetermined wave shape is stacked by being folded back in a zigzag manner, and thus the total length of the coil 100 that is yet to be annularly molded can be compact. Accordingly, the size of a transport device transporting the coil 100 can be reduced. In addition, the connecting portion 15 to be folded back has the continuous wire, and thus the layers 10 to 60 are not scattered in the connecting portion 15 and handling of the coil 100 is facilitated. Moreover, for mounting in the stator core 200, the coil wire 1 stacked in six layers has only to be rounded by one lap and does not have to be rounded in a substantially spiral shape unlike in the related art, and thus each coil wire 1 can be easily incorporated into the slot 201.
In the coil 100 of the present embodiment, the stacking direction of the six coil wires 1 between the adjacent layers, such as the layers 10 and 20 and the layers 20 and 30, is reversed, and the folding direction and the stacking direction of the six coil wires 1 correspond to each other in the connecting portion 15. This configuration will be further described with reference to
Focusing on the coil wire 1a, for example, the coil wire 1a is disposed on the outermost side of the connecting portion 15 in the connecting portion 15 when the layer 10 is folded back in the connecting portion 15 whereas the coil wire 1a is disposed on the farthest side in the radial direction (D31 direction side) in the layer 10. As a result, when the coil wire 1a is folded back, the coil wire 1a is disposed on the nearest side in the radial direction (D32 direction side) in the layer 20. In other words, each of the coil wires 1a to if is folded back in the connecting portion 15 while maintaining the stacking order in each layer, and thus the stacking direction is reversed to the direction from D32 to D31. The stacking order is maintained in the connecting portion 15. Accordingly, in the folding order of the coil wires 1a to if in each connecting portion 15, the layer that is on the farthest side (D31 direction side) in the immediately preceding layer (layer on the upper side in
As a result, a wave winding coil stacked in a plurality of layers can be easily manufactured by sequential insertion of each previously folded coil wire 1 (1a to 1f) from the folding direction (direction along the D2 direction illustrated in
When the coil 100 stacked in a sheet shape is rounded for mounting in the stator core 200, the diameter of the coil 100 decreases toward the radially inner layer 60 with respect to the layer 10 on the radial-direction outside of the stator core 200, and an inner-outer circumferential difference occurs as the length in the circumferential direction also decreases toward the radially inner layer 60. Accordingly, it is preferable to be capable of eliminating the inner-outer circumferential difference as follows.
In a case where the interval of the slot accommodating portion 11 is changed, molding may be performed such that the interval of the slot accommodating portion 11 in the vicinity of the coil end portion 12 constituting the folded part of the coil wire 1, that is, the connecting portion 15 is smaller than the interval of the slot accommodating portion 11 at parts other than the vicinity of the folded part of the coil wire 1. In other words, molding is performed such that the interval of the slot accommodating portion 11 in the vicinity of the coil end portion 12 constituting each connecting portion 15, which is the folded part, is small without a change in the interval of the respective slot accommodating portions 11 in the vicinity of the middle portions of the layers 10 to 60. According to this, the positions of the slot accommodating portions 11 in the vicinity of the middle portions of the layers 10 to 60 can be aligned, and thus central positions O of the layers 10 to 60 can be aligned in the folded coil wire 1 as illustrated in
As illustrated in
In the coil 100 of the present embodiment, each coil wire 1 is preferably a continuous wire that is continuous throughout the stacked layers 10 to 60. Since the entire coil 100 can be manufactured with one continuous wire, the number of joints can be minimized with no limitation and manufacturing processes for the coil 100 can be simplified.
The embodiment of the present invention can be appropriately modified or omitted within the scope of the invention. For example, the number of layers constituting the coil is not limited to six insofar as it is two or more. The number of coil wires constituting one layer is not limited to six.
Number | Date | Country | Kind |
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JP2018-026665 | Feb 2018 | JP | national |
Number | Name | Date | Kind |
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20040119362 | Neet | Jun 2004 | A1 |
20090096311 | Even | Apr 2009 | A1 |
20170324286 | Akimoto et al. | Nov 2017 | A1 |
Number | Date | Country |
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101084618 | Dec 2007 | CN |
2000-139051 | May 2000 | JP |
2004-282996 | Oct 2004 | JP |
2013-138594 | Jul 2013 | JP |
2013-243904 | Dec 2013 | JP |
2014-007938 | Jan 2014 | JP |
2015-126630 | Jul 2015 | JP |
2016-92997 | May 2016 | JP |
Entry |
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Japanese Office Action dated Nov. 12, 2019, 3 pages. |
Chinese Office Action dated Aug. 3, 2020, 9 pages. |
Number | Date | Country | |
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20190260249 A1 | Aug 2019 | US |