WO2024114005A1

WO2024114005A1 - Axial flux motor and stator cooling structure therefor, and manufacturing method for the stator cooling structure

Info

Publication number: WO2024114005A1
Application number: PCT/CN2023/116168
Authority: WO
Inventors: 刘洋; 何俊明; 陈文杰; 章小林; 王一奇; 朱敏; 杨晨
Original assignee: 浙江盘毂动力科技有限公司
Priority date: 2022-11-30
Filing date: 2023-08-31
Publication date: 2024-06-06
Also published as: CN115882622A

Abstract

An axial flux motor and a stator cooling structure therefor, and a manufacturing method for the stator cooling structure. The cooling structure comprises a stator housing (110), wherein the stator housing (110) comprises an upper metal plate (111), a middle partition plate (112) and a lower metal plate (113), which are joined in an axial direction; the stator housing (110) is provided with several iron core mounting holes (110a) arranged at intervals in a circumferential direction, and each iron core mounting hole (110a) sequentially penetrates the upper metal plate (111), the middle partition plate (112) and the lower metal plate (113); a yokeless iron core (120) is mounted in each iron core mounting hole (110a), and has two ends exposed on two sides of the stator housing (110); coils (130) are sleeved on both the ends of the yokeless iron core (120) exposed on the two sides of the stator housing (110); and a surface where the upper metal plate (111) and the middle partition plate (112) are joined is provided with an upper flow channel (111a), a surface where the lower metal plate (113) and the middle partition plate (112) are joined is provided with a lower flow channel (113a), and the middle partition plate (112) is provided with a middle hole (112a) connecting the upper flow channel (111a) and the lower flow channel (113a).

Description

Axial magnetic field motor and stator cooling structure and manufacturing method thereof

Technical Field

The invention relates to the field of stator cooling, and in particular to an axial magnetic field motor with a yokeless iron core and a stator cooling structure and a manufacturing method thereof.

Background technique

Axial magnetic field motors, also known as disc motors, have the advantages of small size, high torque density, high power density and high efficiency, and are widely used in electric vehicles, general industry and other fields. The motor includes a housing, a stator and a rotor, and the stator and the rotor are arranged inside the housing. During the operation of the motor, heat is generated inside the stator, and for reasons of safety and motor efficiency, the heat needs to be discharged.

At present, the heat is discharged by passing the cooling fluid through the stator. However, due to space and insulation problems, some non-insulated cooling fluids can only pass through the stator through a designed cooling path. For example, CN216056503U discloses a disc motor stator that is easy to dissipate heat. The stator uses cooling paths between the core windings and the radial inner and outer sides of the core windings. The cooling paths include an inner circulation channel, an outer circulation channel and a water cooling channel. The cooling fluid flows back and forth between the inner circulation and the outer circulation in turn through each water cooling channel. Although the cooling effect can be achieved, there are the following defects:

First, the heat generated by the iron core needs to be transferred to the cooling fluid through the coil, that is, the iron core is far away from the cooling path, resulting in poor heat dissipation inside the iron core.

Second, the cooling path occupies the circumferential space of the coil, reducing the occupancy rate of the winding in the slot.

Third, each coil is separated by a water cooling channel, which is not conducive to connecting the coils to form a winding.

Fourth, the cooling path includes an inner circulation channel, an outer circulation channel and a water cooling channel. It can be seen that the cooling path is complex and the casting difficulty is relatively large.

Summary of the invention

In order to solve the above problems, the present invention provides an axial magnetic field motor and its stator cooling structure and manufacturing method that directly wrap the iron core without occupying the circumferential space of the coil, thereby improving the coil slot full rate, while reducing the molding difficulty and achieving manufacturability.

According to one object of the present invention, the present invention provides an axial magnetic field motor stator cooling structure, comprising:

A stator housing, the stator housing comprising an upper metal plate, a middle partition plate and a lower metal plate spliced in the axial direction, the stator housing being provided with a plurality of core mounting holes arranged at intervals in the circumferential direction, each of the core mounting holes sequentially penetrating the upper metal plate, the middle partition plate and the lower metal plate;

A plurality of yokeless iron cores, wherein the yokeless iron cores are installed in the iron core installation holes and have two ends exposed on both sides of the stator housing;

A plurality of coils, wherein the coils are sleeved on the yokeless iron core, and coils are sleeved on both ends of the yokeless iron core exposed on both sides of the stator housing;

An upper flow channel is arranged on the surface where the upper metal plate and the middle partition are spliced, a lower flow channel is arranged on the surface where the lower metal plate and the middle partition are spliced, and a middle hole connecting the upper flow channel and the lower flow channel is arranged on the middle partition.

As a preferred embodiment, an upper flow channel opening groove is provided on the upper metal plate, and the middle partition covers the upper flow channel opening groove to form the upper flow channel. A lower flow channel opening groove is provided on the lower metal plate, and the middle partition covers the lower flow channel opening groove to form the lower flow channel.

As a preferred embodiment, the middle hole is respectively connected to the upper flow channel opening groove and the lower flow channel opening groove and communicates with the upper flow channel opening groove and the lower flow channel opening groove.

As a preferred embodiment, sealant is provided between the middle partition and the upper metal plate, and between the middle partition and the lower metal plate.

As a preferred embodiment, the middle partition is a flexible material plate, and the upper metal plate and the lower metal plate are thermally conductive metal. Belongs to the board.

As a preferred embodiment, an upper accommodating portion is provided on the outer side of the upper metal plate away from the middle partition, and a lower accommodating portion is provided on the outer side of the lower metal plate away from the middle partition, and the coils located on both axial sides of the yokeless iron core are respectively arranged in the upper accommodating portion and the lower accommodating portion.

As a preferred embodiment, it also includes:

A plurality of slot wedges are respectively arranged on both axial sides of the yokeless iron core, each slot wedge is respectively inserted between two adjacent yokeless iron cores, and the coil is abutted between the slot wedge and the stator housing.

As a preferred embodiment, an insulating heat conductive member is provided between the yokeless core and the coil;

And/or, an insulating heat-conducting member is provided between the coil and the stator housing.

According to another object of the present invention, the present invention also provides an axial magnetic field motor, which includes the axial magnetic field motor stator cooling structure of the above-mentioned embodiment, and the axial magnetic field motor also includes two rotors, and the two rotors are maintained at the axial sides of the yokeless iron core with air gaps.

According to another object of the present invention, the present invention also provides a method for manufacturing an axial magnetic field motor stator cooling structure, comprising the following steps:

a. Provide a stator housing, the stator housing is provided with a plurality of core mounting holes arranged at circumferential intervals, the stator housing comprises an upper metal plate, a middle partition plate and a lower metal plate, the core mounting holes sequentially penetrate the upper metal plate, the middle partition plate and the lower metal plate, the upper metal plate has an upper splicing portion, the upper splicing portion is provided with an upper flow channel, the lower metal plate has a lower splicing portion, the lower splicing portion is provided with a lower flow channel, and the middle partition plate is provided with a plurality of intermediate holes;

b. splicing the middle partition between the upper splicing part and the lower splicing part so that the middle hole communicates with the upper flow channel and the lower flow channel;

c. inserting a yokeless iron core into the iron core mounting hole;

d. Coils are sleeved on both axial sides of the yokeless iron core, and the coils are maintained on both axial sides of the stator housing.

Compared with the prior art, this technical solution has the following advantages:

The stator housing is retained in the middle section of the yokeless iron core, and the two coils sleeved on the yokeless iron core are retained on both axial sides of the stator housing, so that the upper flow channel and the lower flow channel arranged in the stator housing can simultaneously perform contact heat exchange with the yokeless iron core and the coils, thereby effectively improving the cooling effect.

Since the two coils sleeved on the yokeless iron core are maintained on both axial sides of the stator housing, the coils on the same side are connected to form a winding. Compared with the traditional coil arrangement between the iron core and the stator cooling structure, the increase in the circumferential space design and the defect of low winding occupancy rate in the slot are avoided.

The stator housing is a split structure, so that the upper flow channel and the lower flow channel can be easily processed, and then the upper metal plate, the middle partition plate and the lower metal plate can be spliced to achieve manufacturability and reduce casting difficulty. In addition, by setting the middle hole on the middle partition plate, the cooling medium can circulate between the upper flow channel and the lower flow channel, and the upper flow channel and the lower flow channel are arranged along the axial direction of the yokeless iron core, which increases the heat exchange area, improves fluidity, and thus enhances cooling performance.

The present invention is further described below with reference to the accompanying drawings and embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of the stator cooling structure of the axial magnetic field motor according to the present invention;

FIG2 is a front view of the stator housing of the present invention;

Fig. 3 is a cross-sectional view along the A-A direction in Fig. 2;

FIG4 is a schematic structural diagram of the middle partition of the present invention;

FIG5 is a schematic structural diagram of a first embodiment of an upper metal plate according to the present invention;

FIG6 is a schematic structural diagram of a first embodiment of the lower metal plate of the present invention;

FIG7 is a schematic diagram of a first embodiment of the combination of the upper flow channel and the lower flow channel of the present invention;

FIG8 is a schematic structural diagram of a second embodiment of the upper metal plate of the present invention;

FIG9 is a schematic structural diagram of a second embodiment of the lower metal plate of the present invention;

FIG10 is a schematic diagram of a second embodiment of the combination of the upper flow channel and the lower flow channel of the present invention;

FIG11 is a schematic structural diagram of a third embodiment of the upper metal plate of the present invention;

FIG12 is a schematic structural diagram of a third embodiment of the lower metal plate of the present invention;

FIG13 is a schematic diagram of a third embodiment of the combination of the upper flow channel and the lower flow channel of the present invention;

FIG14 is a schematic structural diagram of a third embodiment of the combination of the upper flow channel and the lower flow channel of the present invention;

FIG15 is an exploded view of the axial magnetic field motor of the present invention;

FIG16 is a cross-sectional view of the gap along the core mounting hole in the axial magnetic field motor of the present invention;

FIG17 is a cross-sectional view along the center of the core mounting hole of the axial magnetic field motor of the present invention;

FIG18 is a schematic structural diagram of another embodiment of the stator housing of the present invention;

FIG. 19 is a schematic diagram of the eddy current path in the stator according to the present invention.

Detailed ways

The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

First embodiment

As shown in FIGS. 1 to 3 , the axial magnetic field motor stator cooling structure comprises:

A stator housing 110, the stator housing 110 comprises an upper metal plate 111, a middle partition plate 112 and a lower metal plate 113 which are spliced in the axial direction, and the stator housing 110 is provided with a plurality of core mounting holes 110a which are arranged at intervals in the circumferential direction, and each of the core mounting holes sequentially penetrates the upper metal plate 111, the middle partition plate 112 and the lower metal plate 113;

A plurality of yokeless iron cores 120, wherein the yokeless iron cores 120 are installed in the iron core installation hole 110a with both ends exposed at both sides of the stator housing 110;

A plurality of coils 130 , wherein the coils 130 are sleeved on the yokeless core 120 , and the coils 130 are sleeved on both ends of the yokeless core 120 exposed on both sides of the stator housing 110 ;

An upper flow channel 111a is arranged on the surface where the upper metal plate 111 and the middle partition 112 are spliced, a lower flow channel 113a is arranged on the surface where the lower metal plate 113 and the middle partition 112 are spliced, and a middle hole 112a connecting the upper flow channel 111a and the lower flow channel 113a is arranged on the middle partition 112.

When the yokeless core 120 is inserted into the core mounting hole 110a, the stator housing 110 is maintained in the middle section of the yokeless core 120, and the two coils 130 sleeved on the yokeless core 120 are maintained on both axial sides of the stator housing 110, so that the upper flow channel 111a and the lower flow channel 113a arranged in the stator housing 110 can simultaneously perform contact heat exchange with the yokeless core 120 and the coils 130, effectively improving the cooling effect. In addition, since the two coils 130 sleeved on the yokeless core 120 are maintained on both axial sides of the stator housing 110, so that the coils 130 on the same side are connected and form a winding, compared with the traditional coil arrangement between the core and the stator cooling structure, the increase in the circumferential space design is avoided, and the defect of low winding occupancy rate in the slot is avoided. In addition, the stator housing 110 is a split structure, so that the upper flow channel 111a and the lower flow channel 113a can be easily processed, and then the upper metal plate 111, the middle partition 112 and the lower metal plate 113 can be spliced to achieve manufacturability and reduce casting difficulty. And by setting the middle hole 112a on the middle partition 112, the cooling medium can circulate between the upper flow channel 111a and the lower flow channel 113a, and the upper flow channel 111a and the lower flow channel 113a are arranged along the axial direction of the yokeless iron core 120, increasing the heat exchange area, improving fluidity, and thus enhancing cooling performance.

As shown in FIGS. 2 to 6, 8, 9, 11, 12 and 15, the upper metal plate 111 has an upper joint portion 1112 and an upper receiving portion 1111 opposite to each other, and a plurality of iron bars passing through the upper joint portion 1112 and the upper receiving portion 1111. The upper core mounting portion 1113, the lower metal plate 113 has a lower splicing portion 1132 and a lower accommodating portion 1131 relative to each other, and a plurality of lower core mounting portions 1133 penetrating the lower splicing portion 1132 and the lower accommodating portion 1131, and the middle partition plate 112 is provided with a plurality of middle core mounting portions 1123 and a plurality of middle holes 112a, and the middle core mounting portions 1123 and the middle holes 112a are arranged at intervals. After the middle partition plate 112 is spliced between the upper splicing portion 1112 and the lower splicing portion 1132, the upper core mounting portion 1113, the middle core mounting portion 1123 and the lower core mounting portion 1133 form the core mounting hole 110a correspondingly, and the middle hole 112a is connected to the upper flow channel 111a and the lower flow channel 113a.

Specifically, the upper metal plate 111, the middle partition plate 112 and the lower metal plate 113 are generally in the form of sheets, so as to assemble and form the disc-shaped stator housing 110, that is, the axial dimension of the stator housing 100 is small, so as to reflect the characteristic of the small axial dimension of the axial magnetic field motor. The middle partition plate 112 is the thinnest and can be made of metal or non-metal material, and the outer contour of the stator housing 110 can be circular or square, etc., and a through hole is opened in the center of the stator housing 110 for setting the rotating shaft 300 and the bearing 400, refer to FIG. 15. In addition, the upper core mounting portion 1113, the middle core mounting portion 1123 and the lower core mounting portion 1133 have the same shape, which is trapezoidal, and form a trapezoidal core mounting hole 110a correspondingly to adapt to the installation of the trapezoidal yokeless core 120, referring to Figures 2 and 15, wherein the trapezoidal upper bottom of the core mounting hole 110a is set inward, and the trapezoidal lower bottom of the core mounting hole 110a is set outward.

More specifically, the upper metal plate 111 is provided with an upper flow channel opening groove 111a0, and the middle partition 112 covers the upper flow channel opening groove 111a0 to form the upper flow channel 111a, and the lower metal plate 113 is provided with a lower flow channel opening groove 113a0, and the middle partition 112 covers the lower flow channel opening groove 113a0 to form the lower flow channel 113a.

The upper runner opening groove 111a0 is processed on the upper joint portion 1112 exposed to the outside of the upper metal plate 111, and the lower runner opening groove 113a0 is processed on the lower joint portion 1132 exposed to the outside of the lower metal plate 113, and then the middle partition plate 112 is spliced between the upper metal plate 111 and the lower metal plate 113 to form the upper runner 111a and the lower runner 113a. The middle hole 112a is connected to the upper runner opening groove 111a0 and the lower runner opening groove 113a0 respectively and communicates with the upper runner opening groove 111a0 and the lower runner opening groove 113a0. In addition, the upper metal plate 111, the middle partition 112 and the lower metal plate 113 can also be formed by stamping to reduce the difficulty of casting, and at the same time facilitate the cleaning of the exposed upper flow channel opening groove 111a0 and the lower flow channel opening groove 113a0, which is equivalent to the traditional built-in water channel method. After the water channel is processed and formed, its inner wall is rough and cannot be cleaned, and it is easy to cause problems such as blockage.

Referring to Fig. 3, the middle partition 112 is sealedly connected to the upper metal plate 111 and the lower metal plate 113, respectively, and the sealing connection includes setting a sealant, a sealing ring or welding. Taking the upper metal plate 111 and the middle partition 112 as an example, a sealant is set between the middle partition 112 and the upper joint 1112 of the upper metal plate 111 to ensure the sealing between the two and prevent the cooling medium (including cooling water, cooling oil or cooling gas) from leaking.

The middle partition plate 112 is a flexible material plate, such as a rubber plate, etc. The upper metal plate 111 and the lower metal plate 113 are heat-conducting metal plates to enhance their support and heat exchange capabilities.

Referring to Figure 1, the upper metal plate 111, the middle partition plate 112 and the lower metal plate 113 are arranged along the axial direction of the yokeless iron core 120, the upper accommodating portion 1111 is used to arrange the coil 130, the upper flow channel 111a arranged on the upper splicing portion 1112 can cool the coil 130 in the upper accommodating portion 1111, and similarly, the lower flow channel 113a arranged on the lower splicing portion 1132 cools the coil 130 in the lower accommodating portion 1131, and the upper flow channel 111a and the lower flow channel 113a can cool the yokeless iron core 120 at the same time, rationally utilizing the space and effectively ensuring the cooling capacity of the coil 130 and the yokeless iron core 120.

It should be noted that the upper flow channel 111a and the lower flow channel 113a are separated by the middle partition 112 and are connected only through the middle hole 112a, so that the cooling medium can fully pass through the upper flow channel 111a and the lower flow channel 113a, thereby improving the cooling effect.

As shown in FIG. 1 and FIG. 15 , the axial magnetic field motor stator cooling structure 100 further includes:

A plurality of slot wedges 140 are respectively provided on both axial sides of the yokeless iron core 120 , each slot wedge 140 is respectively inserted between two adjacent yokeless iron cores 120 , and the coil 130 is abutted between the slot wedge 140 and the stator housing 110 .

Specifically, the circumferential sides of the yokeless iron core 120 are respectively arranged in the core slots 121, and the slot wedges 140 are respectively inserted into the core slots 121 of two adjacent yokeless iron cores 120 in the radial direction to fix the coil 130 between the slot wedges 140 and the stator housing 110.

1 and 3 , the upper accommodating portion 1111 and the lower accommodating portion 1131 are both embedded grooves, so that the coil 130 can be embedded in the upper accommodating portion 1111 and the lower accommodating portion 1131, and the coil 130 abuts between the bottom of the embedded groove and the slot wedge 140. The yokeless iron core 120 and the slot wedge 140 are respectively substantially flush with the axial side surfaces of the stator housing 110, and there is a gap between the coil 130 and the side wall of the embedded groove, which can be used to fill the potting glue, that is, the upper accommodating portion 1111 and the lower accommodating portion 1131 are filled with potting glue to fix the stator housing 110, the coil 130, the yokeless iron core 120, etc.

In addition, the connection part 131 of the coil 130 is located on the radially outer side thereof, and the connection part 131 is located in the gap between the coil 130 and the side wall of the embedded slot, and the connection between the coils 130 on the same side can be carried out in the gap. Specifically, the coils 130 can be sleeved on each of the yokeless cores 120 one by one, and then the connection between the coils 130 can be carried out between the coils 130 and the side wall of the embedded slot, so that the coils 130 can be connected to form a winding. Of course, the coils 130 on the same side can be connected to form a whole through the connection part 131 first, and then connected to the yokeless core 120 together.

As shown in Figure 1, an insulating heat-conducting member is provided between the yokeless core 120 and the coil 130. The insulating heat-conducting member can be a ceramic sheet or insulating paper, so as to ensure the insulation and heat conduction between the two, avoid eddy current loss, and affect the motor operation performance. Specifically, the outer periphery of the yokeless core 120 can be wrapped with insulating paper, and then the coil 130 is arranged outside the insulating paper to achieve insulation between the yokeless core 120 and the coil 130. It should be noted that the two axial end faces of the yokeless core 120 are air gap faces, and the insulating paper should avoid being blocked.

In addition, an insulating heat-conducting member may be provided between the coil 130 and the stator housing 110 . The insulating heat-conducting member is provided between the coil 130 and the bottom of the embedding groove to achieve insulation between the coil 130 and the stator housing 110 .

Second embodiment

The axial magnetic field motor stator cooling structure of the second embodiment is different from that of the first embodiment in that, referring to FIGS. 4 to 6 , the upper flow channel 111a includes an upper main flow channel 111a1 and an upper branch flow channel 111a2, the upper main flow channel 111a1 is arranged to be connected to the upper branch flow channel 111a2 at one end and to be connected to an external water channel at the other end, the upper branch flow channel 111a2 is arranged around the yokeless core 120 and forms a flow channel notch 1110a on the inner side of the yokeless core 120;

The lower flow channel 113a includes a lower main flow channel 113a1 and a lower branch flow channel 113a2. The lower main flow channel 113a1 is arranged to be connected to the lower branch flow channel 113a2 at one end and to be connected to an external water channel at the other end. The lower branch flow channel 113a2 is arranged around the yokeless core 120 and forms a flow channel gap 1110a on the inner side of the yokeless core 120.

The middle hole 112a is connected to the upper branch flow channel 111a2 and the lower branch flow channel 113a2 on the flow channel notch 1110a side.

The number of the upper branch channel 111a2 and the lower branch channel 113a2 are both multiple, the upper main channel 111a1 is connected to the external water channel, and the cooling medium introduced from the outside is introduced into the multiple upper branch channels 1111a, and then each upper branch channel 1111a introduces the cooling medium into the lower branch channel 113a2 through the middle hole 112a, and then the cooling medium flows into the lower main channel 113a1, and finally is discharged through the external water channel connected to the lower main channel 113a1. The upper flow channel 111a and the lower flow channel 113a are arranged at intervals along the axial direction of the yokeless iron core 120, and the upper branch channel 111a2 and the lower branch channel 113a2 are arranged around the yokeless iron core 120 respectively, so as to increase the heat exchange area and make the cooling medium evenly pass through the upper flow channel 111a and the lower flow channel 113a, thereby improving the cooling effect.

As shown in Figures 4 and 6, the upper branch channel 111a2 is connected to the lower branch channel 113a2 through two middle holes 112a at both ends of the channel notch 1110a, and the upper main channel 111a1 is connected to the upper branch channel 111a2 at the outside of the yokeless iron core 120; the lower main channel 113a1 is connected to the lower branch channel 113a2 at the outside of the yokeless iron core 120.

The upper main channel 111a1 is located on the radial outside of the yokeless iron core 120, and the lower main channel 113a1 is also located on the radial outside of the yokeless iron core 120. The upper branch channel 111a2 and the lower branch channel 113a2 are arranged at intervals, and the upper branch channel 111a2 and the lower branch channel 113a2 are respectively arranged around the yokeless iron core 120. In addition, since the channel notch 1110a is located on the radial inside of the yokeless iron core 120, the heat exchange area between the upper branch channel 111a2 and the lower branch channel 113a2 and the yokeless iron core 120 is increased, thereby improving the cooling performance.

As shown in FIG. 5 and FIG. 6 , the upper main flow channel 111a1 includes a water inlet 111a11 and a water inlet loop 111a12, the water inlet loop 111a12 surrounds the outer side of the yokeless core 120, the water inlet 111a11 connects the water inlet loop 111a12 and the outer side wall of the upper metal plate 111, and the upper branch flow channel 111a2 connects the water inlet loop 111a12;

The lower main channel 113a1 includes a water outlet 113a11 and a water outlet loop 113a12. The water outlet loop 113a12 surrounds the outer side of the yokeless iron core 120. The water outlet 113a11 connects the water outlet loop 113a12 and the outer side wall of the lower metal plate 113. The lower branch channel 113a2 connects the water outlet loop 113a12.

The water inlet 111a11 and the water outlet 113a11 are used to connect to external waterways, including connecting to external water pipes, etc. The water inlet 111a11 is used to introduce cooling medium, and the water outlet 113a11 is used to discharge cooling medium. Preferably, when the middle partition 112 is spliced between the upper metal plate 111 and the lower metal plate 113, the water inlet 111a1 and the water outlet 113a1 are arranged opposite to each other, which is convenient for centralized external pipes and management. The water inlet loop 111a12 and the water outlet loop 113a12 are loops connected end to end in sequence.

Continuing to refer to FIG. 5 and FIG. 6 , the upper branch flow channel 111a2 includes a water inlet branch 111a21, an upper branch 111a22 on the outer ring of the core, and an upper branch 111a23 between the cores. The water inlet branch 111a21 is connected between the water inlet loop 111a12 and the upper branch 111a22 on the outer ring of the core. Both ends of the upper branch 111a22 on the outer ring of the core are respectively connected to the upper branch 111a23 between the cores. The upper branch 111a23 between the cores is arranged between two adjacent yokeless cores 120, and the flow channel gap 1110a is formed between the two upper branches 111a23 between the cores on the inner side of the yokeless core 120.

The lower branch flow channel 113a2 includes a water outlet branch 113a21, a lower branch 113a22 of the outer ring of the core and a lower branch 113a23 between the cores. The water outlet branch 113a21 is connected between the water outlet loop 113a12 and the lower branch 113a22 of the outer ring of the core. Both ends of the lower branch 113a22 of the outer ring of the core are respectively connected to the lower branch 113a23 between the cores. The lower branch 113a23 between the cores is arranged between two adjacent yokeless cores 120, and the flow channel gap 1110a is formed between the two lower branches 113a23 between the cores on the inner side of the yokeless core 120.

There are multiple upper branch channels 111a2 and lower branch channels 113a2. When the middle partition plate 112 is spliced between the upper metal plate 111 and the lower metal plate 113, the upper branch channels 111a2 and the lower branch channels 113a2 are spaced apart to ensure that each of the yokeless iron cores 120 can be surrounded by the channel and the cooling medium can pass through evenly.

As shown in Fig. 5, the flow channel gap 1110a is formed between two adjacent upper branches 111a23 between the cores, and located inside the yokeless core 120. As shown in Fig. 6, the flow channel gap 1110a is formed between two adjacent lower branches 113a23 between the cores, and located inside the yokeless core 120.

As shown in Figures 4 to 7, the cooling medium is introduced through the water inlet 111a11, and then flows along the water inlet loop 111a12 and through a plurality of the water inlet branches 111a21 into the connected upper branch 111a22 of the outer ring of the core, and then the cooling medium in the upper branch 111a22 of the outer ring of the core flows into the two upper branches 111a23 between the cores connected to it, and then flows into the corresponding lower branch 113a23 between the cores through the middle hole 112a, and the cooling medium in the lower branch 113a23 between the cores passes through the lower branch 113a22 of the outer ring of the core in turn until it flows into the water outlet loop 113a21, and finally is collected and discharged from the water outlet 113a11. Reasonable design of the cooling flow path not only increases the heat exchange area and improves the fluidity of the cooling medium, but also avoids the design limitations of the cooling path that cause some heat to not be discharged in time or cause a large temperature gradient, thereby causing adverse effects on the stator or failing to enable the motor to achieve satisfactory output capacity.

As shown in FIG18 , the flow channel notch 1110a is provided with a flow cut-off seam 1110a1, which penetrates the stator housing 110 in the axial direction and connects the core mounting hole 110a and the inner wall of the stator housing 110, and each core mounting hole 110a is connected to a corresponding flow cut-off seam 1110a1, and the flow cut-off seam 1110a1 extends in the radial direction to block the stator eddy current path 1001 where it is located, refer to FIG19 . Further explanation, each of the cores 120 generates a stator eddy current. Eddy current path 1001, the stator eddy current path 1001 is composed of a plurality of elliptical loop paths arranged from the inside to the outside, the interrupting gap 1110a1 refers to a gap arranged in the radial direction and axially penetrating the stator housing 110, and the gap blocks each elliptical loop path, thereby achieving the effect of reducing eddy current loss. In addition, a closed ring can be added to the inner side wall of the stator housing 110, and the closed ring can be a closed ring made of metal material, and an insulating member can be added between the stator housing 110 and the closed ring to ensure structural strength and achieve insulation effect.

Third embodiment

The axial magnetic field motor stator cooling structure of the third embodiment is different from that of the second embodiment in that, referring to FIGS. 8 to 10 , the upper flow channel 111a includes a plurality of upper branch waterways 111a3 extending in the radial direction, the upper branch waterways 111a3 are arranged between adjacent yokeless cores 120 and have upper ports 111a31 on the inner side of the yokeless core 120, and two adjacent upper branch waterways 111a3 are separated from each other on the inner side of the yokeless core 120 to form a blocking space 1110b;

The lower flow channel 113a includes a plurality of lower branch waterways 113a3 extending in the radial direction, the lower branch waterways 113a3 are arranged between adjacent yokeless cores 120 and have lower ports 113a31 on the inner side of the yokeless core 120, and two adjacent lower branch waterways 113a3 are separated from each other on the inner side of the yokeless core 120 to form a blocking space 1110b;

The middle partition plate 112 is provided with a middle hole 112 a , and the middle hole 112 a connects the upper port 111 a 31 of the upper branch water channel 111 a 3 and the lower port 113 a 31 of the lower branch water channel 113 a 3 on the inner side of the yokeless iron core 120 .

When the middle partition plate 112 is spliced between the upper metal plate 111 and the lower metal plate 113, the upper branch water channel 111a3 and the lower branch water channel 113a3 correspond to each other. By setting the blocking space 1110b, the corresponding upper branch water channel 111a3 and the lower branch water channel 113a3 are connected through the middle hole 112a. The upper port 111a31 and the lower port 113a31 are both located on the radial inner side of the yokeless iron core 120, ensuring the heat exchange area and improving the cooling performance.

8 and 9, the upper flow channel 111a further includes a water inlet 111a11 and a water inlet loop 111a12, the water inlet loop 111a12 surrounds the outer side of the yokeless core 120, the water inlet 111a11 connects the water inlet loop 111a12 and the outer side wall of the upper metal plate 111, and the upper branch waterway 111a3 connects the water inlet loop 111a12;

The lower flow channel 113a also includes a water outlet 113a11 and a water outlet loop 113a12. The water outlet loop 113a12 surrounds the outer side of the yokeless iron core 120. The water outlet 113a11 connects the water outlet loop 113a12 and the outer side wall of the lower metal plate 113. The lower branch water channel 113a3 is connected to the water outlet loop 113a12.

As shown in Figures 8 to 10, the cooling medium is introduced through the water inlet 111a11, then flows along the water inlet loop 111a12 and through the plurality of upper branches 111a3 between the cores. The cooling medium in the upper branch 111a3 between the cores flows into the lower branch 113a3 between the cores through the middle hole 112a, then flows into the water outlet loop 113a12, and finally is collected and discharged from the water outlet 113a11. Reasonable design of the cooling flow path not only increases the heat exchange area and improves the fluidity of the cooling medium, but also avoids the design limitations of the cooling path that cause some heat to not be discharged in time or cause a large temperature gradient, thereby causing adverse effects on the stator or failing to enable the motor to achieve satisfactory output capacity.

In order to reduce eddy current loss, a flow interrupting slit 1110a1 may also be provided on the blocking space 1110b. The specific contents may refer to the flow interrupting slit 1110a1 of the second embodiment, which will not be described in detail here.

Fourth embodiment

The axial magnetic field motor stator cooling structure of the fourth embodiment is different from that of the second embodiment in that, with reference to FIGS. 11 to 14 , the upper flow channel 111a includes an upper main flow channel 111a1, a first upper branch flow channel 111a4 and a second upper branch flow channel 111a5, the upper main flow channel 111a1 is connected to the first upper branch flow channel 111a4, the second upper branch flow channel 111a5 is independently arranged, the first upper branch flow channel 111a4 and the second upper branch flow channel 111a5 are arranged around the yokeless core 120 and form a flow channel gap 1110a on the inner side of the yokeless core 120;

The lower flow channel 113a includes a lower main flow channel 113a1, a first lower branch flow channel 113a4 and a second lower branch flow channel 113a5. The lower main flow channel 113a1 is connected to the first lower branch flow channel 113a4, and the second lower branch flow channel 113a5 is independently arranged. The first lower branch flow channel 113a4 and the second lower branch flow channel 113a5 are arranged around the yokeless iron core 120 and are arranged inside the yokeless iron core 120. A flow channel gap 1110a is formed;

The middle partition plate 112 is provided with a middle hole 112a, and the middle hole 112a is arranged on both sides of the flow channel gap 1110a, the first upper branch channel 111a4 and the second lower branch channel 113a5 are connected through the middle hole 112a, the second upper branch channel 111a5 and the first lower branch channel 113a4 are connected through the middle hole 112a, and the second upper branch channel 111a5 and the second lower branch channel 113a5 are connected through the middle hole 112a.

The upper main channel 111a1 is used to guide the cooling medium to the first upper branch channel 111a4 connected to it, and then the first upper branch channel 111a4 guides the cooling medium to the second lower branch channel 113a5 through the middle hole 112a, the second lower branch channel 113a5 guides the cooling medium to the second upper branch channel 111a5 through the middle hole 112a, the second upper branch channel 111a5 guides the cooling medium to the first lower branch channel 113a4 through the middle hole 112a, and finally the cooling medium is discharged through the lower main channel 113a1.

It can be seen that the first upper runner 111a4, the second lower runner 113a5, the second upper runner 111a5, and the first lower runner 113a4 are connected in sequence. And when the middle partition 112 is spliced between the upper metal plate 111 and the lower metal plate 113, the first upper runner 111a4, the second lower runner 113a5, the second upper runner 111a5, and the first lower runner 113a4 that are connected in sequence are partially staggered and extended in the circumferential direction, ensuring that water channels are arranged around each of the yokeless iron cores 120 to ensure the cooling effect.

11 and 12, the second upper flow channels 111a5 include multiple independent channels, and the first upper flow channels 111a4 include multiple independent channels. Similarly, the second lower flow channels 113a5 include multiple independent channels, and the first lower flow channels 113a4 include multiple independent channels.

Specifically, there are two first upper branch channels 111a4, which are respectively connected to the two ends of the upper main channel 111a1, and there are four second lower branch channels 113a5. Each of the first upper branch channels 111a4 corresponds to two second lower branch channels 113a5, so that the two sides of the first upper branch channel 111a4 are connected to the second upper branch channel 111a5 through a second lower branch channel 113a5.

Continuing to refer to FIG. 11 and FIG. 12 , the first upper branch flow channel 111a4 includes a first water inlet branch 111a41, a first core outer ring upper branch 111a42 and a first inter-core upper branch 111a43, the first water inlet branch 111a41 connects the upper main flow channel 111a1 and the first core outer ring upper branch 111a42, the first core outer ring upper branch 111a42 connects two first inter-core upper branches 111a43, and the first inter-core upper branch 111a43 is disposed between two adjacent unyoke cores 120;

The second upper branch channel 111a5 includes a second core outer ring upper branch 111a52 and a second inter-core upper branch 111a53, the second core outer ring upper branch 111a52 connects three second inter-core upper branches 111a53, and the second inter-core upper branch 111a53 is arranged between two adjacent yokeless cores 120;

The first lower branch channel 113a4 includes a first water outlet branch 113a41, a first core outer ring lower branch 113a42 and a first inter-core lower branch 113a43, wherein the first water outlet branch 113a41 connects the lower main channel 113a1 and the first core outer ring lower branch 113a42, the first water outlet branch 113a41 connects the center of the first core outer ring lower branch 113a42, the first core outer ring lower branch 113a42 connects four first inter-core lower branches 113a43, and the first inter-core lower branch 113a43 is arranged between two adjacent yokeless cores 120;

The second lower branch channel 113a5 includes a second core outer ring lower branch 113a52 and a second inter-core lower branch 113a53, wherein the second core outer ring lower branch 113a52 connects two second inter-core lower branches 113a53, and the second inter-core lower branch 113a53 is arranged between two adjacent yokeless cores 120.

The upper main flow channel 111a1 includes a water inlet 111a11 and a water inlet loop 111a12, the water inlet loop 111a12 surrounds the outer side of the yokeless core 120, the water inlet 111a11 connects the water inlet loop 111a12 and the outer side wall of the upper metal plate 111, and the first upper branch flow channel 111a4 connects the water inlet loop 111a12;

The lower main channel 113a1 includes a water outlet 113a11 and a water outlet loop 113a12. The water outlet loop 113a12 surrounds the outer side of the yokeless iron core 120. The water outlet 113a11 connects the water outlet loop 113a12 and the outer side wall of the lower metal plate 113. The first lower branch channel 113a4 is connected to the water outlet loop 113a12.

The water inlet loop 111a12 and the water outlet loop 113a12 are semi-circular loops, and the curvature thereof is approximately 90°. The water inlet loop 111a12 and the water outlet loop 113a12 are staggered in the circumferential direction, wherein the water outlet loop 113a12 deviates 90° relative to the water inlet loop 111a12, so that the center line connecting the two first water inlet branches 111a41 is perpendicular to the center line connecting the two first water outlet branches 113a41. In this way, the cooling medium introduced by the first water inlet branch 111a41 is divided into two paths, and the path angle of each path on the stator housing 110 is 90°, which can make the cooling medium pass evenly and improve the cooling effect.

As shown in Figures 11 to 14, the cooling medium is introduced through the water inlet 111a11, then flows along the water inlet loop 111a12 and through the two first water inlet branches 111a41 into the first upper branch channel 111a4 connected thereto, and then the first upper branch channel 111a4 leads the cooling medium to the second lower branch channel 113a5 through the middle hole 112a, and the second lower branch channel 113a5 leads the cooling medium to the second upper branch channel 111a5 through the middle hole 112a, and the second upper branch channel 111a5 leads the cooling medium to the first lower branch channel 113a4 through the middle hole 112a, and finally the cooling medium is discharged through the lower main channel 113a1. Reasonable design of the cooling channel path not only increases the heat exchange area and improves the fluidity of the cooling medium, but also avoids the design limitations of the cooling path that cause some heat to not be discharged in time or cause a large temperature gradient, thereby causing adverse effects on the stator or failing to enable the motor to achieve satisfactory output capacity.

Fifth embodiment

As shown in Figures 15 to 17, the axial magnetic field motor includes an axial magnetic field motor stator cooling structure 100 of any one of the first to fourth embodiments, and the axial magnetic field motor also includes two rotors 200, and the two rotors 200 are maintained on both axial sides of the yokeless iron core 120 with an air gap.

Since the axial magnetic field motor adopts the axial magnetic field motor stator cooling structure 100 of the above embodiment, the beneficial effects of the axial magnetic field motor refer to the axial magnetic field motor stator cooling structure 100 of the above embodiment.

Continuing to refer to Figures 12 and 17, the axial magnetic field motor also includes a rotating shaft 300 and at least one bearing 400. The rotating shaft 300 passes through the center of the stator housing 110. The bearing 400 is arranged between the rotating shaft 300 and the stator housing 110. The rotor 200 is fixed on the rotating shaft 300, and the rotor 200 and the stator 100 are maintained with an air gap.

As shown in FIG15 , the rotor 200 includes a rotor disk 210 and a plurality of magnetic steels 220. The plurality of magnetic steels 220 are arranged on the rotor disk 210 at circumferential intervals, and the magnetic steels 220 are maintained in an air gap with the yokeless core 120. When the magnetic steels 220 are arranged on the rotor disk 210, the magnetic steels 220 slightly protrude from the surface of the rotor disk 210 to cooperate with the core 130 in an air gap.

The rotor 200 further includes a plurality of pressure plates 230 , wherein a pressure plate 230 is disposed between two adjacent magnetic steels 220 , and the pressure plate 230 is fixed to the magnetic steel receiving groove by fasteners, and uses an inclined surface to adapt to the circumferential side surface of the magnetic steel 220 to perform axial and circumferential positioning of the magnetic steel 220 .

The magnetic steel 220 is formed by stacking a plurality of silicon steel sheets in a radial direction, and a cut-off surface is formed between two adjacent silicon steel sheets. The cut-off surface can block the eddy current path of the magnetic steel, thereby achieving the effect of suppressing eddy current loss.

The magnetic steel 220 is trapezoidal, and the number thereof is consistent with the number of the yokeless iron core 120. The upper bottom of the trapezoid of the magnetic steel 220 is arranged inward, and the lower bottom of the trapezoid of the magnetic steel 220 is arranged outward. That is, the width of the plurality of silicon steel sheets 221 constituting the magnetic steel 220 increases from the inside to the outside in the radial direction.

As shown in Fig. 15, the number of the stator 100 is one, the number of the rotor 200 is two, and the two rotors 200 are held at both axial sides of the stator 100 with air gaps to form an axial magnetic field motor with a single stator and two rotors. Of course, an axial magnetic field motor with a single stator and a single rotor, or a double stator and a single rotor can be obtained according to the different numbers.

Sixth embodiment

As shown in FIGS. 1 to 3 , the manufacturing method of the axial magnetic field motor stator cooling structure is used to manufacture the axial magnetic field motor stator cooling structure 100 of any one of the first to third embodiments, and the method comprises the following steps:

a. A stator housing 110 is provided, wherein the stator housing 110 is provided with a plurality of core mounting holes 110a spaced apart in the circumferential direction, the stator housing 110 comprises an upper metal plate 111, a middle partition plate 112 and a lower metal plate 113, the core mounting holes 110a sequentially penetrate the upper metal plate 111, the middle partition plate 112 and the lower metal plate 113, the upper metal plate 111 has an upper splicing portion 1112, an upper flow channel 111a is provided on the upper splicing portion 1112, the lower metal plate 113 has a lower splicing portion 1132, a lower flow channel 113a is provided on the lower splicing portion 1132, and a plurality of intermediate holes 112a are provided on the middle partition plate 112;

b. Splicing the middle partition plate 112 between the upper splicing portion 1112 and the lower splicing portion 1132, so that the middle hole 112a communicates with the upper flow channel 111a and the lower flow channel 113a;

c. Inserting the yokeless core 120 into the core mounting hole 110;

d. The coils 130 are sleeved on both axial sides of the yokeless core 120 , and the coils 130 are maintained on both axial sides of the stator housing 110 .

The shapes of the upper flow channel 111a and the lower flow channel 113a refer to the first to third embodiments and are not described here. The stator housing 110 is a split structure, so that the upper flow channel 111a and the lower flow channel 113a can be formed by processing, and then the upper metal plate 111, the middle partition 112 and the lower metal plate 113 can be spliced to achieve manufacturability and reduce casting difficulty. At the same time, it is convenient to clean the upper flow channel 111a exposed on the upper splicing part 1112 and the lower flow channel 113a exposed on the lower splicing part 1132.

In step b, the middle partition plate 112 is sealed and connected between the upper metal plate 111 and the lower metal plate 113 to increase the sealing performance. The sealing connection includes setting a sealant, a sealing ring or welding.

The upper metal plate 111 is penetrated by an upper core mounting portion 1113, the lower metal plate 113 is penetrated by an lower core mounting portion 1133, and the middle partition is penetrated by an iron core middle mounting portion 1123. Furthermore, in step b, the upper core mounting portion 1113, the iron core middle mounting portion 1123 and the iron core lower mounting portion 1133 form an iron core mounting hole 110a correspondingly.

After step d, the method further comprises:

A slot wedge 140 is inserted between two adjacent yokeless cores 120 , so that the coil 130 abuts between the slot wedge 140 and the stator housing 110 .

The upper metal plate 111 is provided with an upper accommodating portion 1111, and the lower metal plate 113 is provided with a lower accommodating portion 1131. The upper accommodating portion 1111 and the lower accommodating portion 1131 in which the coil 130 is embedded are filled with potting glue to fix the stator housing 110, the coil 130, the yokeless iron core 120, etc.

The embodiments described above are only used to illustrate the technical ideas and features of the present invention, and their purpose is to enable technicians in this field to understand the content of the present invention and implement it accordingly. The patent scope of the present invention cannot be limited only by this embodiment, that is, any equivalent changes or modifications made according to the spirit disclosed by the present invention still fall within the patent scope of the present invention.

Claims

An axial magnetic field motor stator cooling structure (100), characterized by comprising:

A stator housing (110), the stator housing (110) comprising an upper metal plate (111), a middle partition plate (112) and a lower metal plate (113) spliced in the axial direction, the stator housing (110) being provided with a plurality of iron core mounting holes (110a) spaced apart in the circumferential direction, each of the iron core mounting holes sequentially penetrating the upper metal plate (111), the middle partition plate (112) and the lower metal plate (113);

A plurality of yokeless iron cores (120), wherein the yokeless iron cores (120) are installed in the iron core installation hole (110a) and have both ends exposed on both sides of the stator housing (110);

A plurality of coils (130), wherein the coils (130) are sleeved on the yokeless iron core (120), and the coils (130) are sleeved on both ends of the yokeless iron core (120) exposed on both sides of the stator housing (110);

An upper flow channel (111a) is provided on the surface where the upper metal plate (111) and the middle partition (112) are joined, a lower flow channel (113a) is provided on the surface where the lower metal plate (113) and the middle partition (112) are joined, and a middle hole (112a) is provided on the middle partition (112) for connecting the upper flow channel (111a) and the lower flow channel (113a).
The axial magnetic field motor stator cooling structure (100) as described in claim 1 is characterized in that an upper flow channel opening groove (111a0) is provided on the upper metal plate (111), and the middle partition (112) covers the upper flow channel opening groove (111a0) to form the upper flow channel (111a), and a lower flow channel opening groove (113a0) is provided on the lower metal plate (113), and the middle partition (112) covers the lower flow channel opening groove (113a0) to form the lower flow channel (113a).
The axial magnetic field motor stator cooling structure (100) as described in claim 2 is characterized in that a middle hole (112a) is provided on the middle partition plate (112), and the middle hole (112a) is respectively connected to the upper flow channel opening groove (111a0) and the lower flow channel opening groove (113a0) and connects the upper flow channel opening groove (111a0) and the lower flow channel opening groove (113a0).
The axial magnetic field motor stator cooling structure (100) according to claim 3 is characterized in that a sealant is provided between the middle partition (112) and the upper metal plate (111), and between the middle partition (112) and the lower metal plate (113).
The axial magnetic field motor stator cooling structure (100) according to claim 1 is characterized in that the middle partition plate (112) is a flexible material plate, and the upper metal plate (111) and the lower metal plate (113) are heat-conducting metal plates.
The axial magnetic field motor stator cooling structure (100) as described in claim 1 is characterized in that an upper accommodating portion (1111) is provided on the outer side of the upper metal plate (111) away from the middle partition (112), and a lower accommodating portion (1131) is provided on the outer side of the lower metal plate (113) away from the middle partition (112), and the coils (130) located on both axial sides of the yokeless iron core (120) are respectively arranged in the upper accommodating portion (1111) and the lower accommodating portion (1131).
The axial magnetic field motor stator cooling structure (100) according to claim 1, characterized in that it also includes:

A plurality of slot wedges (140) are provided on both axial sides of the yokeless iron core (120), each slot wedge (140) is inserted between two adjacent yokeless iron cores (120), and the coil (130) is abutted between the slot wedge (140) and the stator housing (110).
The axial magnetic field motor stator cooling structure (100) according to claim 1, characterized in that an insulating heat conductive member is provided between the yokeless core (120) and the coil (130);

And/or, an insulating heat-conducting member is provided between the coil (130) and the stator housing (110).
An axial magnetic field motor, characterized in that it comprises an axial magnetic field motor stator cooling structure (100) as described in any one of claims 1 to 8, and the axial magnetic field motor also comprises two rotors (200), and the two rotors (200) are maintained at both axial sides of the yokeless iron core (120) with an air gap.
A method for manufacturing an axial magnetic field motor stator cooling structure, characterized in that it comprises the following steps:

a. providing a stator housing (110), the stator housing (110) being provided with a plurality of core mounting holes (110a) spaced apart in the circumferential direction, the stator housing (110) comprising an upper metal plate (111), a middle partition plate (112) and a lower metal plate (113), the core mounting holes (110a) sequentially penetrating the upper metal plate (111), the middle partition plate (112) and the lower metal plate (113), the upper metal plate (111) having an upper splicing portion (1112), the upper splicing portion (1112) being provided with an upper flow channel (111a), the lower metal plate (113) having a lower splicing portion (1132), the lower splicing portion (1132) being provided with a lower flow channel (113a), The middle partition plate (112) is provided with a plurality of middle holes (112a);

b. splicing the middle partition plate (112) between the upper splicing portion (1112) and the lower splicing portion (1132) so that the middle hole (112a) communicates with the upper flow channel (111a) and the lower flow channel (113a);

c. inserting a yokeless iron core (120) into the iron core mounting hole (110);

d. The coils (130) are sleeved on both axial sides of the yokeless iron core (120), and the coils (130) are maintained on both axial sides of the stator housing (110).