JP2014209829A - Stator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator capable of achieving excellent torque characteristics while reducing iron loss.SOLUTION: A stator comprises a plurality of split cores adjacent in the circumferential direction and having an annular shape as a whole, and configured so that a parallel slot having a constant width in the circumferential direction or a trapezoidal slot having a circumferential width increasing toward the inner diameter side and a trapezoidal slot having a circumferential width decreasing toward the inner diameter side appear alternately in the circumferential direction; and a coil provided in each slot of the plurality of split cores. One parallel slot or a trapezoidal slot having a circumferential width increasing toward the inner diameter side is formed in each of the plurality of split cores, and a trapezoidal slot having a circumferential width decreasing toward the inner diameter side is formed between respective adjacent split cores.

Description

  The present disclosure relates to a stator.

  2. Description of the Related Art Conventionally, a stator of a rotating electrical machine formed by incorporating a plurality of divided cores into a coil integrated body formed in an annular shape (cylindrical shape) in advance is known (see, for example, Patent Document 1). In the configuration of Patent Document 1, the plurality of divided cores are formed in a shape that divides one slot and divides one slot between adjacent divided cores in the circumferential direction. Each slot is a parallel slot having the same shape and a constant width in the circumferential direction. That is, each divided core forms one parallel slot at the central portion in the circumferential direction, and forms a half portion of each parallel slot on both sides in the circumferential direction.

JP 2012-235696 A

  By the way, generally, when the stator core is formed of a plurality of divided cores, the smaller the number of divisions, the smaller the loss (iron loss) on the divided surface. In this respect, since the parallel slot is used in the configuration described in Patent Document 1, it is not necessary to divide every slot, which is advantageous in that the number of divisions can be reduced. However, in the case of a parallel slot, the tooth shape is tapered (the inner diameter side is narrowed), so the magnetic flux density is reduced at the root of the tooth and increased at the tip of the tooth. Therefore, a restriction on the maximum magnetic flux density (saturation of magnetic flux) occurs at the tip of the teeth, which is disadvantageous from the viewpoint of torque characteristics.

  Therefore, an object of the present disclosure is to provide a stator capable of realizing good torque characteristics while reducing iron loss.

According to one aspect of the present disclosure, there are a plurality of split cores that are adjacent to each other in the circumferential direction and have an annular shape as a whole. The parallel cores have a constant circumferential width or the circumferential width goes toward the inner diameter side A plurality of split cores configured as a whole such that trapezoidal slots that increase and trapezoidal slots that decrease in width in the circumferential direction alternately appear in the circumferential direction;
A coil provided in each slot of the plurality of split cores,
One of the parallel slots or a trapezoidal slot whose circumferential width increases toward the inner diameter side is formed in each of the plurality of split cores, and a trapezoidal slot whose circumferential width decreases toward the inner diameter side, A stator is provided formed between each adjacent split core.

  According to the present disclosure, a stator capable of realizing good torque characteristics while reducing iron loss can be obtained.

Sectional drawing of the stator 1 by one Example (Example 1) is shown. FIG. 2 is a view showing only an A portion of the stator 1 shown in FIG. 1. It is a figure which shows a comparative example. It is sectional drawing of a part of stator 2 by other one Example (Example 2). It is sectional drawing of a part of stator 3 by other one Example (Example 3). It is sectional drawing of the stator 4 by other one Example (Example 4). It is a perspective view which shows the coil | winding integrated body 300 by one Example.

  Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a cross-sectional view of a stator 1 according to one embodiment. FIG. 2 is a view showing only the portion A of the stator 1 shown in FIG. Hereinafter, the radial direction, the circumferential direction, and the axial direction define the inner diameter side and the outer diameter side with the central axis I as the center, with the central axis I of the stator 1 as a reference. For example, the inner diameter side refers to the side close to the central axis I in the radial direction of the central axis I.

  The stator 1 may be used with any motor of the inner rotor type. For example, the stator 1 may be used in a traveling motor used in a hybrid vehicle or an electric vehicle. The traveling motor may be, for example, a permanent magnet motor, or may be a hybrid motor that uses both an electromagnet and a permanent magnet.

  As shown in FIG. 1, the stator 1 includes a plurality of divided cores 10 and a coil 30. In the example shown in FIG. 1, a ring member 40 is provided on the outer periphery of the plurality of split cores 10. The ring member 40 has a function of restraining the plurality of divided cores 10. The ring member 40 may be provided on the outer periphery of the plurality of split cores 10 by shrink fitting, for example.

  As shown in FIG. 1, the plurality of divided cores 10 are annularly adjacent to each other in the circumferential direction. Each divided core 10 may be formed of a laminated steel plate, for example. Each of the plurality of divided cores 10 has the same configuration. The number of divided cores 10 (the number of divisions) is arbitrary, but may be determined according to the number of magnetic poles and the number of phases. In the example shown in FIG. 1, the stator 1 is for a three-phase motor having eight magnetic poles, and includes 24 (8 × 3) divided cores 10.

  As shown in FIG. 1, the plurality of divided cores 10 are configured as a whole so that parallel slots 120 and trapezoidal slots 140 appear alternately in the circumferential direction. For example, the total number of parallel slots 120 and trapezoidal slots 140 (ie, the number of slots) may be formed at a ratio of two per phase with respect to the number of magnetic poles of the motor. In the example shown in FIG. 1, the stator 1 is for a three-phase motor having eight magnetic poles, and the number of slots is 48 (8 × 3 × 2).

  As shown in FIG. 2, the parallel slot 120 is a slot having a constant circumferential width W1. One parallel slot 120 is formed in each of the plurality of split cores 10. Therefore, the number of parallel slots 120 is equal to the number of split cores 10.

  As shown in FIG. 2, the trapezoidal slot 140 is a slot whose width W2 in the circumferential direction becomes smaller toward the inner diameter side. The trapezoidal slot 140 is formed between the adjacent divided cores 10. That is, each divided core 10 cooperates with each adjacent divided core 10 to define a trapezoid slot 140.

  Therefore, in the present embodiment, each divided core 10 includes two teeth portions 12 and a back yoke portion 14. The two tooth portions 12 of each divided core 10 have a line-symmetric shape. The two teeth portions 12 of each divided core 10 have a shape in which the inner diameter side (tip side) becomes narrower. The width W3 of the tip end portion of the tooth portion 12 is determined so that necessary torque characteristics are realized (no saturation of magnetic flux occurs). In addition, since the two teeth parts 12 of each divided core 10 are line symmetrical, the width W3 of the front-end | tip part of all the teeth parts 12 is equal.

  The back yoke portion 14 preferably provides a constant back yoke width in the circumferential direction in order to make the torque characteristics uniform in the circumferential direction (in order not to form a region where the magnetic flux easily flows and a region where it is difficult to flow). . That is, the back yoke width L1 of the parallel slot 120 is preferably equal to the back yoke width L2 of the trapezoidal slot 140. In this case, the back yoke width L1 (= L2) is determined so as to realize a necessary torque characteristic (a predetermined maximum magnetic flux passes through the back yoke portion 14).

  The coil 30 is provided in each parallel slot 120 and each trapezoidal slot 140. The winding cross section of the coil 30 may have a rectangular shape or another shape. The coil 30 may be wound around the plurality of split cores 10 in any manner. For example, the coil 30 may be formed by a winding integrated body integrated in an annular shape as disclosed in JP 2012-235696 A. The winding integrated body has a tooth housing portion that receives the tooth portion 12 of each divided core 10. Each teeth accommodating portion includes a space corresponding to the shape of the tooth portion 12. Each divided core 10 may be assembled to the winding assembly by inserting each tooth portion 12 into a tooth accommodating portion of the corresponding winding assembly (inserting from the outer diameter side of the winding assembly). The detailed structure of the winding integrated body may be arbitrary. The coil 30 may be formed of a molded edgewise coil as disclosed in JP 2010-104102 A. An example of the winding integrated body will be described later.

  As shown in FIG. 2, the coil 30 includes a first coil part 31 located in the parallel slot 120 and a second coil part 32 located in the trapezoidal slot 140. In a preferred example, the cross-sectional area S1 of the first coil part 31 and the cross-sectional area S2 of the second coil part 32 are equal. That is, in a preferred example, the conductor area S1 in the parallel slot 120 is equal to the conductor area S2 in the trapezoidal slot 140. Here, “equal” means that a substantive difference such as an error (tolerance) is allowed. As a result, the first coil portion 31 in the parallel slot 120 and the second coil portion 32 in the trapezoidal slot 140 have the same current density, and the heat generation characteristics can be made uniform. Hereinafter, the description will be continued assuming that the conductor area S1 in the parallel slot 120 is equal to the conductor area S2 in the trapezoidal slot 140.

  3A and 3B are diagrams showing a comparative example. FIG. 3A shows a split core 90 of a stator in which all slots are parallel slots as Comparative Example 1, and FIG. A stator split core 92 is shown in which the slots are trapezoidal slots.

  In Comparative Example 1 shown in FIG. 3A, the tooth shape of the split core 90 is tapered (the inner diameter side becomes narrower), so that the magnetic flux density decreases at the tooth root and increases at the tooth tip. Therefore, in Comparative Example 1 shown in FIG. 3A, the maximum magnetic flux density (magnetic flux saturation) is restricted at the tip of the tooth.

  In this respect, also in the present embodiment, the tooth portion 12 has a shape in which the inner diameter side becomes narrower. However, in this embodiment, the trapezoidal slot 140 is formed on both sides of the parallel slot 120, so that the necessary width W3 of the tip portion of the tooth portion can be efficiently ensured. Specifically, in Comparative Example 1, in order to secure the width W3 of the tip portion of the tooth portion, it is necessary to reduce the width W5 of the parallel slot, so that the same conductor area (S5 = S1) is realized. For this purpose, it is necessary to increase the radial length L5 of the parallel slot. On the other hand, according to the present embodiment, the trapezoidal slots 140 are formed on both sides of the parallel slot 120, so that the width W3 of the tip portion of the tooth portion can be secured without reducing the width W1 of the parallel slot. it can. That is, since W1> W5, the radial length of the parallel slot 120 can be reduced by that amount (that is, the inner diameter R of the stator 1 (see FIG. 1) is made larger than that of the first comparative example). Or the lamination thickness of the stator 1 can be reduced).

  In Comparative Example 2 shown in FIG. 3B, since all the slots are trapezoidal slots, the teeth shape has a constant width (an ideal shape with a constant magnetic flux density), which is advantageous from the viewpoint of torque generation. . However, in Comparative Example 2, it is necessary to perform division at the trapezoidal slot in order to ensure assemblability. This is because in Comparative Example 2, since all the slots are trapezoidal slots, the width W7 between the two teeth is smaller than the width W8 of the coil portion to be accommodated in the trapezoidal slot. That is, in Comparative Example 2, if there is no division along the division line D1, the division core 92 cannot be assembled to the winding integrated body from the outer diameter side. As a result, in Comparative Example 2, the number of divided cores 92 increases. That is, the number of divisions increases (in the case of the same number of slots, the number of divisions is twice that of Comparative Example 1). This means that the loss (iron loss) on the split surface becomes large.

  On the other hand, according to the present embodiment, it is necessary to divide at the trapezoidal slot 140, but the parallel slot 120 and the trapezoidal slot 140 are alternately formed, so that the number of divisions can be reduced. That is, according to the present embodiment, since the number of trapezoidal slots 140 is half of the number of trapezoidal slots in Comparative Example 2, the same number of divisions as in Comparative Example 1 can be realized as shown in FIG. it can.

  In this way, according to the present embodiment, it is possible to achieve good torque characteristics while reducing the number of divisions.

  In the configuration shown in FIG. 2, the shape of the trapezoidal slot 140 may be the same as the shape of the trapezoidal slot in Comparative Example 2. At this time, the width W1 of the parallel slot 120 may be determined so that the conductor area is S1 = S2 and the back yoke width is L1 = L2. At this time, the center line of the tooth portion 12 does not pass through the center axis I.

  FIG. 4 is a cross-sectional view of a part of the stator 2 according to another embodiment (embodiment 2). The stator 2 of the second embodiment includes a plurality of split cores 10A in a different split mode from the first embodiment described above. Specifically, in the second embodiment, the dividing line between the divided cores 10 </ b> A is set at the circumferential end of the trapezoidal slot 140. In the first embodiment described above, the dividing line between the divided cores 10 is set at the center in the circumferential direction of the trapezoidal slot 140. As described above, the dividing line may be set at an arbitrary position within the circumferential range (lower bottom portion) of the trapezoidal slot 140.

  FIG. 5 is a cross-sectional view of a part of the stator 3 according to another embodiment (embodiment 3). The stator 3 according to the third embodiment includes a plurality of split cores 10B and 10C in a split manner different from that of the first embodiment. Specifically, in the third embodiment, the divided cores 10B and the divided cores 10C are alternately arranged in the circumferential direction and have different configurations. However, the split cores 10B and 10C are different from the split core 10 of the first embodiment described above only in the shape of the back yoke portions 14B and 14C (that is, the two tooth portions 12 of each of the split cores 10B and 10C). Is the same as the two tooth portions 12 of the split core 10 of the first embodiment described above). The dividing line between the divided core 10B and the divided core 10C is set within the circumferential range of the trapezoidal slot 140. Thus, the shape of the back yoke portion may be different for each adjacent divided core.

  FIG. 6 is a cross-sectional view of the stator 4 according to another embodiment (embodiment 4). In the stator 4 of the fourth embodiment, the parallel slot 120 is replaced with a trapezoidal slot 130 (hereinafter referred to as “reverse trapezoidal slot 130” for distinction from the trapezoidal slot 140) as compared with the first embodiment. The main differences are. The inverted trapezoidal slot 130 is a slot whose circumferential width increases toward the inner diameter side. One inverted trapezoidal slot 130 is formed in each of the plurality of split cores 10. Therefore, the number of antiparallel slots 120 is equal to the number of split cores 10.

  Also in the fourth embodiment, the two tooth portions 12 of each divided core 10 have a line-symmetric shape. The two teeth portions 12 of each divided core 10 have a shape in which the inner diameter side (tip side) becomes narrower. The width W3 of the tip end portion of the tooth portion 12 is determined so that necessary torque characteristics are realized. In addition, since the two teeth parts 12 of each divided core 10 are line symmetrical, the width W3 of the front-end | tip part of all the teeth parts 12 is equal.

  In addition, the coil 30 includes a first coil part 33 located in the antiparallel slot 130 and a second coil part 32 located in the trapezoidal slot 140. In a preferred example, the cross-sectional area of the first coil part 33 and the cross-sectional area of the second coil part 32 are equal. That is, in a preferred example, the conductor area in antiparallel slot 130 is equal to the conductor area in trapezoidal slot 140. As a result, the first coil part 33 in the antiparallel slot 130 and the second coil part 32 in the trapezoidal slot 140 have the same current density, and the heat generation characteristics can be made uniform.

  Also according to the fourth embodiment, substantially the same effect as the first embodiment described above can be obtained. That is, it is possible to realize good torque characteristics while reducing the number of divisions.

  The configuration of the fourth embodiment can be combined with the second and third embodiments described above. That is, in the second and third embodiments described above, the parallel slot 120 may be replaced with a similar inverted trapezoidal slot 130.

  FIG. 7 is a perspective view showing a winding assembly 300 according to an embodiment. In the example shown in FIG. 7, the winding integrated body 300 forms the coil 30 of the stator 1 of the first embodiment described above.

  The winding assembly 300 includes a coil end portion 302 and a coil body 304 provided in the parallel slot 120 and the trapezoidal slot 140. The coil body 304 forms a cross-sectional portion of the coil 30 shown in the cross-sectional view of FIG. The coil body 304 includes a part 304 a that forms the first coil part 31 located in the parallel slot 120 and a part 304 b that forms the second coil part 32 located in the trapezoidal slot 140. A teeth container 310 is defined between the portion 304a and the portion 304b in the circumferential direction. Note that, as described above, each divided core 10 is assembled to the winding assembly 300 by inserting each tooth portion 12 into the corresponding tooth accommodating portion 310 of the winding assembly 300 (inserting from the outer diameter side). .

  Although each embodiment has been described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope described in the claims. It is also possible to combine all or a plurality of the components of the above-described embodiments.

1, 2, 3 Stator 10, 10A, 10B, 10C Split core 12 Teeth part 14, 14B, 14C Back yoke part 30 Coil 31 First coil part 32 Second coil part 40 Ring member 120 Parallel slot 140 Trapezoid slot

Claims (7)

A plurality of split cores that are adjacent to each other in the circumferential direction and have an annular shape as a whole, and a parallel slot having a constant circumferential width or a trapezoidal slot that increases in width toward the inner diameter side and a circumferential width A plurality of split cores configured as a whole such that trapezoidal slots that become smaller as they go to the inner diameter side appear alternately in the circumferential direction;
A coil provided in each slot of the plurality of split cores,
One of the parallel slots or a trapezoidal slot whose circumferential width increases toward the inner diameter side is formed in each of the plurality of split cores, and a trapezoidal slot whose circumferential width decreases toward the inner diameter side, A stator formed between adjacent divided cores.   2. The stator according to claim 1, wherein each of the plurality of divided cores includes two tooth portions, and a circumferential width of a tip portion of each tooth portion is equal.   2. The stator according to claim 1, wherein each of the plurality of divided cores includes two line-symmetrical tooth portions, and each of the tooth portions has a shape in which a circumferential width decreases toward an inner diameter side.   The stator according to any one of claims 1 to 3, wherein the plurality of divided cores have the same shape.   The stator according to any one of claims 1 to 4, wherein a conductor area in the parallel slot is equal to a conductor area in the trapezoidal slot.   The stator according to any one of claims 1 to 5, wherein a back yoke width of the parallel slot in the split core is equal to a back yoke width of the trapezoidal slot in the split core.   The stator according to any one of claims 1 to 6, wherein the coil is formed of a coil assembly formed in an annular shape.

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