CN108110917B

CN108110917B - Stator

Info

Publication number: CN108110917B
Application number: CN201611062474.4A
Authority: CN
Inventors: 许宏成; 林欣政; 简嘉兴
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2016-11-25
Filing date: 2016-11-25
Publication date: 2020-07-31
Anticipated expiration: 2036-11-25
Also published as: CN108110917A

Abstract

A stator is applied to an electric motor. The stator includes a hollow core and a plurality of windings. The hollow iron core is provided with two opposite surfaces and a plurality of accommodating grooves communicated to the surfaces. The containing grooves are arranged in a ring shape. Each winding comprises a plurality of conducting wires wound by the accommodating grooves. The parts of the conducting wires of the winding, which are positioned in the accommodating grooves, are concentrically arranged in the radial direction to form a plurality of winding layers. In at least one of the accommodating grooves, the wire section area of the wire arranged on the innermost winding layer is smaller than that of the wire arranged on the outermost winding layer.

Description

Stator

Technical Field

The invention relates to a stator applied to a motor

Background

In the stator of the electric motor, due to the low voltage application or the high power requirement, the wire wound in the receiving slot usually needs a sufficient cross-sectional area to withstand the larger current, and the prior art uses a plurality of strands of wire with the same cross-sectional area or a single copper wire with a larger cross-sectional area. A single copper wire has the advantage of higher slot occupancy, but due to the relationship between skin effect (skin effect) and proximity effect (proximity effect), the ac loss of a copper wire with a large cross-sectional area increases rapidly with the increase of the motor speed. To solve this problem, it is common practice to reduce the ac loss of the copper wire by reducing the cross-sectional area of a single copper wire by using a plurality of strands having smaller cross-sectional areas of copper wires. However, this approach will result in a decrease in the copper occupancy, a decrease in the effective cross-sectional area of the copper and a resulting increase in the dc resistance, thereby increasing the overall copper loss.

Disclosure of Invention

In view of the above, an objective of the present invention is to provide a stator winding structure that can reduce ac loss of copper wires and has less influence on overall copper loss.

In order to achieve the above object, according to an embodiment of the present invention, a stator is applied to an electric motor. The stator includes a hollow core and a plurality of windings. The hollow iron core is provided with two opposite surfaces and a plurality of accommodating grooves communicated to the surfaces. The containing grooves are arranged in a ring shape. Each winding comprises a plurality of conducting wires wound by the accommodating grooves. The parts of the conducting wires of the winding, which are positioned in the accommodating grooves, are concentrically arranged in the radial direction to form a plurality of winding layers. In at least one of the accommodating grooves, the wire section area of the wire arranged on the innermost winding layer is smaller than that of the wire arranged on the outermost winding layer.

In one or more embodiments of the present invention, in at least one of the receiving grooves, a cross-sectional area of the conductive wire arranged on an inner side of the winding layer is smaller than or equal to a cross-sectional area of the conductive wire arranged on an outer side of the winding layer.

In one or more embodiments of the present invention, the winding layers are sequentially arranged from outside to inside to form at least six layers.

In one or more embodiments of the present invention, in at least one of the accommodating grooves, a cross-sectional area of the conductive wire arranged in the winding layer of the fifth layer is greater than or equal to a cross-sectional area of the conductive wire arranged in the winding layer of the sixth layer.

In one or more embodiments of the present invention, in at least one of the receiving grooves, a sum of a cross-sectional area of the conductive wire arranged in the winding layer of the third layer and a cross-sectional area of the conductive wire arranged in the winding layer of the fourth layer is greater than or equal to a sum of a cross-sectional area of the conductive wire arranged in the winding layer of the fifth layer and a cross-sectional area of the conductive wire arranged in the winding layer of the sixth layer.

In one or more embodiments of the present invention, in at least one of the receiving grooves, a cross-sectional area of the conductive wires arranged in the winding layer of the second layer is larger than a cross-sectional area of at least one of the conductive wires arranged in the winding layers of the third to sixth layers.

In one or more embodiments of the present invention, in at least one of the receiving grooves, a cross-sectional area of the conductive wire arranged in the winding layer of the first layer is greater than or equal to a cross-sectional area of the conductive wire arranged in the winding layer of the second layer.

In one or more embodiments of the present invention, the windings include a first winding, a second winding, and a third winding. The winding layer arranged on the first layer and the winding layer arranged on the second layer form a first winding. The winding layer arranged on the third layer and the winding layer arranged on the fifth layer form a second winding. The winding layer arranged on the fourth layer and the winding layer arranged on the sixth layer form a third winding.

In one or more embodiments of the present invention, at least one of the wires of the second winding is connected in parallel with at least one of the wires of the third winding.

In one or more embodiments of the present invention, at least one of the wires of the second winding or at least one of the wires of the third winding is connected in series with at least one of the wires of the first winding.

In one or more embodiments of the present invention, in at least one of the accommodating slots, the conductive line of the first winding and the conductive line of the second winding are separated by a first insulating layer.

In one or more embodiments of the present invention, in at least one of the accommodating slots, the conducting wires of the second winding and the conducting wires of the third winding are separated by a second insulating layer. The insulation level of the first insulation layer is higher than that of the second insulation layer.

As described above, the stator according to the present invention is designed such that the cross-sectional area of the conductive wire arranged in the innermost winding layer is smaller than the cross-sectional area of the conductive wire arranged in the outermost winding layer. Because the ac loss of the innermost winding layer is greater than the ac loss of the outermost winding layer under the influence of the proximity effect, the ac loss of the stator can be effectively reduced by adjusting the unequal cross-sectional areas, and the reduction of the slot occupation ratio and the increase of the dc loss due to the use of the plurality of copper wires with smaller equal cross-sectional areas are avoided, so that the stator can achieve the purposes of reducing the influence of the proximity effect and reducing the overall loss.

The foregoing is merely illustrative of the problems, solutions to problems, and other aspects of the present invention, and the specific details thereof are set forth in the following description and the related drawings.

Drawings

Fig. 1 is a perspective view illustrating a stator according to an embodiment of the present invention.

Fig. 2 is another perspective view illustrating the stator of fig. 1.

Fig. 3 is a partial cross-sectional view of the stator of fig. 1 taken along line 3-3.

Fig. 4 is a partially enlarged view showing fig. 2.

Fig. 5 is a perspective view illustrating some of the conductive wires wound in the accommodating groove in fig. 4.

Wherein the reference numerals

100: stator

110: hollow iron core

111: first surface

112: second surface

113: containing groove

120A: first winding

120B: second winding

120C: third winding

121a, 121b, 121c, 121d, 121e, 121 f: winding layer

122. 122c, 122d, 122e, 122 f: conducting wire

130: a first insulating layer

140: a second insulating layer

Detailed Description

In the following description, for purposes of explanation, numerous implementation details are set forth in order to provide a thorough understanding of the various embodiments of the present invention. It should be understood, however, that these implementation details are not to be interpreted as limiting the invention. That is, in some embodiments of the invention, such implementation details are not necessary. In addition, some structures and components that are conventional in the art are shown in simplified schematic form in the drawings.

Please refer to fig. 1 to 3. Fig. 1 is a perspective view illustrating a stator 100 according to an embodiment of the present invention. Fig. 2 is another perspective view illustrating the stator 100 of fig. 1. Fig. 3 is a partial cross-sectional view of the stator 100 of fig. 1 taken along line 3-3.

As shown in fig. 1 and 2, in the present embodiment, the stator 100 can be applied to an electric motor. The stator 100 includes a hollow core 110 and a plurality of windings. The hollow core 110 has a first surface 111 (see fig. 1), a second surface 112 (see fig. 2), and a plurality of receiving grooves 113. The first surface 111 and the second surface 112 are respectively located on two opposite sides of the hollow core 110. The receiving groove 113 is connected to the first surface 111 and the second surface 112 (i.e., the receiving groove 113 penetrates the hollow core 110). The receiving grooves 113 are arranged in a ring shape. Each winding includes a plurality of wires 122 wound through the receiving slot 113. In the present embodiment, the accommodating groove 113 is not radially connected to the inner wall of the hollow core 110, but the invention is not limited thereto. In practical applications, the accommodating groove 113 may also be completely or partially communicated with the inner wall of the hollow core 110 in the radial direction.

As shown in fig. 3, the portions of the wires 122 of the winding located in the receiving slot 113 are concentrically arranged in a radial direction into a plurality of winding

layers

121a, 121b, 121c, 121d, 121e, 121 f. In the present embodiment, six layers, such as the winding layer 121a, the winding layer 121b, the winding layer 121c, the winding layer 121d, the winding layer 121e, and the winding layer 121f, are sequentially arranged from the outside to the inside, but the invention is not limited thereto.

In particular, in the present embodiment, in the at least one accommodation groove 113, the cross-sectional area of the conductive wire 122 arranged in the innermost winding layer 121f is smaller than the cross-sectional area of the conductive wire 122 arranged in the outermost winding layer 121 a. Because the ac loss of the innermost winding layer 121f is greater than the ac loss of the outermost winding layer 121a under the influence of the proximity effect, the ac loss of the stator 100 can be effectively reduced by adjusting the unequal cross-sectional areas, and the slot-occupying ratio and the dc loss can be reduced by using a plurality of wires (e.g., copper wires) with smaller equal cross-sectional areas, so that the stator 100 can achieve the purpose of reducing the influence of the proximity effect and reducing the overall loss.

In some embodiments, each conductive line 122 has two portions. The two portions are respectively wound in two corresponding receiving slots 113 and respectively belong to two corresponding winding

layers

121a, 121b, 121c, 121d, 121e, and 121 f. For example, two portions of the conductive wire 122 may span the distance of the six receiving grooves 113, but the present invention is not limited thereto, and may be flexibly adjusted according to actual requirements.

As shown in fig. 3, in the present embodiment, in the at least one accommodation groove 113, a cross-sectional area of the conducting wire 122 arranged on one of the inner sides among the winding

layers

121a, 121b, 121c, 121d, 121e, and 121f may be further designed to be smaller than or equal to a cross-sectional area of the conducting wire 122 arranged on one of the outer sides among the winding

layers

121a, 121b, 121c, 121d, 121e, and 121f, so as to achieve the purpose of reducing the influence of the proximity effect and the overall loss. For example, in some embodiments, in the at least one receiving groove 113, a cross-sectional area of the conductive wire 122 arranged in the winding layer 121e of the fifth layer is greater than or equal to a cross-sectional area of the conductive wire 122 arranged in the winding layer 121f of the sixth layer.

Alternatively, in some embodiments, in the at least one accommodation groove 113, a sum of a cross-sectional area of the conductive wire 122 arranged in the winding layer 121c of the third layer and a cross-sectional area of the conductive wire 122 arranged in the winding layer 121d of the fourth layer is equal to or greater than a sum of a cross-sectional area of the conductive wire 122 arranged in the winding layer 121e of the fifth layer and a cross-sectional area of the conductive wire 122 arranged in the winding layer 121f of the sixth layer.

In some embodiments, in the at least one receiving groove 113, a cross-sectional area of the conductive line 122 arranged in the second winding layer 121b is larger than a cross-sectional area of at least one of the conductive lines 122 arranged in the third winding layer 121c, the fourth winding layer 121d, the fifth winding layer 121e, and the sixth winding layer 121 f.

In another embodiment, in the at least one receiving groove 113, a cross-sectional area of the conductive wire 122 arranged in the first winding layer 121a is greater than or equal to a cross-sectional area of the conductive wire 122 arranged in the second winding layer 121 b.

Also shown in fig. 3, the winding layer 121a arranged in the first layer and the winding layer 121b arranged in the second layer constitute a first winding 120A. The winding layer 121c arranged in the third layer and the winding layer 121e arranged in the fifth layer constitute a second winding 120B. The winding layer 121d arranged in the fourth layer and the winding layer 121f arranged in the sixth layer constitute a third winding 120C.

In addition, the stator 100 of the present embodiment further includes a first insulating layer 130 (see fig. 3 and 4) disposed in the receiving groove 113. In the at least one accommodation groove 113, the conductive line 122 of the first winding 120A and the conductive line 122 of the second winding 120B are separated by a first insulating layer 130. Specifically, the conductive lines 122 arranged in the second winding layer 121b and the conductive lines 122 arranged in the third winding layer 121c are separated by the first insulating layer 130. In addition, in the at least one accommodation groove 113, the conducting wire 122 of the second winding 120B and the conducting wire 122 of the third winding 120C are separated by a second insulating layer 140 (see fig. 4).

In practical applications, such as short-range (relative to full-span) applications, where the same receiving groove 113 may have different phases, the voltage difference is large, so that the first insulating layer 130 may be made of a material with a higher insulating grade, and the second insulating layer 140 may be made of a material with a lower insulating grade. For example, in some embodiments, the first insulating layer 130 is insulating paper or plastic, but the invention is not limited thereto. In some embodiments, the second insulating layer 140 may be a lacquer or a coating layer disposed on the outer surfaces of the wires 122 from the third winding layer 121c to the sixth winding layer 121f, but the invention is not limited thereto.

Please refer to fig. 4 and 5. Fig. 4 is a partially enlarged view showing fig. 2. Fig. 5 is a perspective view illustrating some of the wires wound in the receiving groove 113 in fig. 4. As shown in fig. 5, in the present embodiment, the conductive line 122c and the conductive line 122d form a right-side two-side-by-side V-shaped structure, and the conductive line 122e and the conductive line 122f form a left-side two-side-by-side V-shaped structure. Specifically, the conductive line 122c and the conductive line 122e are part of the second winding 120B (forming a W-shaped structure), so that two portions of the conductive line 122c and the conductive line 122e wound to the two receiving slots 113 are respectively included in the winding layer 121c arranged in the third layer and the winding layer 121e arranged in the fifth layer. The conducting wire 122d and the conducting wire 122f are part of the third winding 120C (forming another W-shaped structure), so that for either the conducting wire 122d or the conducting wire 122f, two portions wound to the two accommodating grooves 113 belong to the winding layer 121d arranged on the fourth layer and the winding layer 121f arranged on the sixth layer, respectively.

Further, from the configuration shown in fig. 5, the lead wire 122C of the second winding 120B is connected in parallel with the lead wire 122d of the third winding 120C (i.e., the two side-by-side V-shaped structures on the right side), the lead wire 122e of the second winding 120B is connected in parallel with the lead wire 122f of the third winding 120C (i.e., the two side-by-side V-shaped structures on the left side), and the two side-by-side V-shaped structures on the right side are connected in series with the two side-by-side V-shaped structures on the left side.

In some embodiments, at least one wire of the second winding or at least one wire of the third winding may be connected in series with at least one wire of the first winding (e.g., connected in series via a jumper).

In practical applications, the stator 100 of the present invention is not limited to include only three windings, and can be flexibly increased or decreased according to the requirement. For example, the stator 100 of the present invention may further include at least one winding. For example, a fourth winding (not shown) may be further added and wound between the second winding 120B and the third winding 120C, and connected in parallel with each other and then connected in series with the first winding 120A. The wires 122 of the first winding 120A to the fourth winding are rearranged from outside to inside into eight winding layers, wherein the first layer and the second layer form the first winding 120A, the third layer and the sixth layer form the second winding 120B, the fourth layer and the seventh layer form the third winding 120C, and the fifth layer and the eighth layer form the fourth winding (not shown). With this configuration, the aforementioned effects of proximity effect and overall loss can be reduced by only satisfying the rule that the cross-sectional area of any conductive wire 122 in the inner winding layer is smaller than or equal to the cross-sectional area of any conductive wire 122 in the outer winding layer.

As is apparent from the above detailed description of the embodiments of the present invention, the stator according to the present invention is designed such that the cross-sectional area of the conductive wire arranged in the innermost winding layer is smaller than the cross-sectional area of the conductive wire arranged in the outermost winding layer. Because the ac loss of the innermost winding layer is greater than the ac loss of the outermost winding layer under the influence of the proximity effect, the ac loss of the stator can be effectively reduced by adjusting the unequal cross-sectional areas, and the reduction of the slot occupation ratio and the increase of the dc loss due to the use of the plurality of copper wires with smaller equal cross-sectional areas are avoided, so that the stator can achieve the purposes of reducing the influence of the proximity effect and reducing the overall loss.

Although the present invention has been described with reference to the above embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and these changes and modifications are intended to be covered by the appended claims.

Claims

1. A stator for use in an electric motor, the stator comprising:

the hollow iron core is provided with two opposite surfaces and a plurality of accommodating grooves communicated with the surfaces, and the accommodating grooves are annularly arranged; and

a plurality of windings, each of the windings including a plurality of wires wound through the receiving slots, wherein portions of the wires of the windings located in the receiving slots are concentrically arranged in a radial direction to form a plurality of winding layers, and a cross-sectional area of the wire arranged on the innermost winding layer is smaller than a cross-sectional area of the wire arranged on the outermost winding layer in at least one of the receiving slots;

wherein, in at least one of the accommodating grooves, the winding layers are sequentially arranged into at least six layers from outside to inside;

the windings comprise a first winding, a second winding and a third winding, the winding layer arranged on the first layer and the winding layer arranged on the second layer form the first winding, the winding layer arranged on the third layer and the winding layer arranged on the fifth layer form the second winding, and the winding layer arranged on the fourth layer and the winding layer arranged on the sixth layer form the third winding;

the wires arranged in the winding layer of the third layer and the wires arranged in the winding layer of the fourth layer are connected in parallel, and the wires arranged in the winding layer of the fifth layer and the wires arranged in the winding layer of the sixth layer are connected in parallel;

the wire arranged in the winding layer of the third layer and the wire arranged in the winding layer of the fifth layer are connected in series to form a second winding, and the wire arranged in the winding layer of the fourth layer and the wire arranged in the winding layer of the sixth layer are connected in series to form a third winding;

each wire of the second winding is wound to two parts of the two accommodating grooves and respectively belongs to the winding layer arranged on the third layer and the winding layer arranged on the fifth layer; each wire of the third winding is wound to two parts of the two accommodating grooves and respectively belongs to the winding layer arranged on the fourth layer and the winding layer arranged on the sixth layer.

2. The stator according to claim 1, wherein in at least one of the slots, a cross-sectional area of the conductive wire disposed on an inner side of the winding layers is smaller than or equal to a cross-sectional area of the conductive wire disposed on an outer side of the winding layers.

3. The stator according to claim 1, wherein in at least one of the receiving slots, a cross-sectional area of the conductive wire of the winding layer arranged in the fifth layer is greater than or equal to a cross-sectional area of the conductive wire of the winding layer arranged in the sixth layer.

4. The stator according to claim 1, wherein in at least one of the receiving slots, a sum of a cross-sectional area of the conductive wire arranged in the winding layer of the third layer and a cross-sectional area of the conductive wire arranged in the winding layer of the fourth layer is equal to or greater than a sum of a cross-sectional area of the conductive wire arranged in the winding layer of the fifth layer and a cross-sectional area of the conductive wire arranged in the winding layer of the sixth layer.

5. The stator according to claim 1, wherein in at least one of the receiving slots, a cross-sectional area of the conductive wires arranged in the winding layer of the second layer is larger than a cross-sectional area of at least one of the conductive wires arranged in the winding layers of the third to sixth layers.

6. The stator according to claim 1, wherein in at least one of the slots, a cross-sectional area of the conductive wire arranged in the winding layer of the first layer is greater than or equal to a cross-sectional area of the conductive wire arranged in the winding layer of the second layer.

7. The stator of claim 1, wherein at least one of the wires of the second winding or at least one of the wires of the third winding is in series with at least one of the wires of the first winding.

8. The stator of claim 1, wherein the conductive line of the first winding and the conductive line of the second winding are separated by a first insulating layer within at least one of the slots.

9. The stator of claim 8, wherein the conductive line of the second winding is separated from the conductive line of the third winding by a second insulation layer in at least one of the slots, wherein the insulation level of the first insulation layer is higher than the insulation level of the second insulation layer.