WO2024046247A1

WO2024046247A1 - Hollow-cup electric motor winding and manufacturing method therefor, and electric motor having hollow-cup electric motor winding

Info

Publication number: WO2024046247A1
Application number: PCT/CN2023/115156
Authority: WO
Inventors: 吕骁; 吕世文
Original assignee: 上海炫脉医疗科技有限公司
Priority date: 2022-08-28
Filing date: 2023-08-28
Publication date: 2024-03-07
Also published as: CN115333273A

Abstract

A hollow-cup electric motor winding and a manufacturing method therefor, and an electric motor having the hollow-cup electric motor winding. The hollow-cup electric motor comprises a multi-turn coil, and the winding (1) comprises at least two sub-windings (2). Each sub-winding (2) comprises a connection area (3) and a working area (4), wherein the diameter of the connection area (3) is not greater than that of the working area (4); the working area (4) comprises a first working section (41) and a second working section (42), and the connection area (3) comprises a filling section (31), two ends of the filling section (31) being respectively connected to the first working section (41) and the second working section (42); and the first working section (41), the second working section (42) and the filling section (31) of each turn are not positioned on the same plane, and the filling sections (31) of different sub-windings (2) have overlapping areas.

Description

Coreless motor winding and manufacturing method and motor with the winding

This application claims priority to the Chinese patent application with application number 202211036353.8, which was submitted to the China Patent Office on August 28, 2022. The entire content of this application is incorporated into this application by reference.

Technical field

The present application relates to a motor, for example, to a coreless motor winding, a manufacturing method, and a motor with the winding.

Background technique

Coreless motors are also called iron-core motors. The core-less motors have the advantages of low electrical energy loss, low rotational inertia, and high mechanical energy. The most important thing is that the coreless motors can be very small, which is beyond the reach of ordinary iron-core motors. Small size, widely used in medical equipment, industrial robots, aerospace and other fields. This kind of motor uses self-adhesive enameled wire to make a cylindrical hollow cup winding. The winding can be placed on either the stator side or the rotor side to provide a magnetic field. Usually, this kind of winding has the following types: overlapping winding, oblique winding and Concentric winding. The ends of the windings overlap each other, causing the thickness of the ends to accumulate, thereby exacerbating the thickness of the two ends of the winding, causing the thickness dimensions to be inconsistent between the ends of the winding and the middle section. This phenomenon will make it difficult to install the windings and the stator. In addition, this phenomenon will also lead to a decrease in the space utilization between the windings and the stator and the rotor, which will then lead to a decrease in the number of winding conductors that can be placed in the motor, and finally cause a decrease in the performance of the motor.

Patent CN106033913B introduces a winding structure that reduces the thickness of the end of a multi-layer coreless motor. The technical defect of this solution is that the winding is wound through a stepped winding bobbin or a gradual winding bobbin, causing the ends of the winding to be staggered. This reduces the thickness of the winding end, but this winding will increase the overall length of the winding, reduce the proportion of the working section in the entire winding, reduce work efficiency, and is not conducive to miniaturization.

Contents of the invention

This application provides a coreless motor winding and a manufacturing method and a motor with the winding to solve the problem of reduced space utilization caused by the large thickness or length of the end of the winding and the reduction of the working section due to the large end of the winding. The problem of reduced winding efficiency caused by the proportion.

According to one aspect of the present application, a coreless motor winding is provided, including a multi-turn coil, the winding including at least two sub-windings, the sub-windings including a connection area and a working area, the diameter of the connection area does not exceed The diameter of the working area, the working area includes a first working section and a second working section, the connecting area includes a filling section, and both ends of the filling section are connected to the first working section and the second working section respectively. ; Moreover, the first working section, the second working section and the filling section of each turn are not located on the same plane, The padding section of each turn is not located on the cylindrical surface where the working area is located, and the padding sections of different sub-windings have overlapping areas.

According to an embodiment, after all the sub-windings are spliced to form the winding, the combined working area is cylindrical or substantially cylindrical.

According to an embodiment, the diameter of the connection area is the maximum diameter of the winding.

According to an embodiment, the sub-winding further includes an overlapping area connected to the working area; and the axial length of the connecting area is smaller than the axial length of the overlapping area.

According to an embodiment, the filling section includes a transition unit and a bending unit. Both ends of the transition unit are connected to the first working section and the bending unit respectively. Both ends of the bending unit are connected to the third unit respectively. The two working sections are connected to the transition unit; and the axial length of the transition unit is the axial length of the connection area.

According to an embodiment, the filling segment is three-dimensional.

According to an embodiment, the transition unit of each turn is located on the same straight line as the first working section.

According to an embodiment, the bending unit is arranged to rotate around the center of the winding; and the bending unit is at least partially arc-shaped, and all the bending units are combined to form a reserved area in the center of the connection area.

According to an embodiment, the reserved area is hole-shaped.

According to an embodiment, the bending unit includes a first connecting piece and a second connecting piece. The first connecting piece is connected to the transition unit and the connection point between the two is a first connecting point. The second connecting piece It is connected to the second working section and the connection point between the two is the second connection point.

According to an embodiment, there is a height difference between the first connection point and the second connection point; and the position of the first connection point is the extreme end of the winding.

According to an embodiment, after all sub-windings are combined, the first connecting piece of the sub-winding has an overlapping area with the second connecting piece of other sub-windings; and, the first working section of the sub-winding and the third connecting piece of other sub-windings The two working sections have overlapping areas.

According to one embodiment, the overlapping area includes a diagonal segment, and each turn of the diagonal segment generally forms a "V" shape after being expanded.

According to an embodiment, the winding method of the overlapping area is a hexagonal winding diagonal winding type.

According to an embodiment, there is a convex annular portion in the overlapping area, and the diameter of the overlapping area is the maximum diameter of the winding.

According to an embodiment, the bending unit is arc-shaped as a whole; or the first connecting piece is arc-shaped. linear shape, and the second connecting piece is arc-shaped.

According to an embodiment, when the bending unit is arc-shaped as a whole, the bending unit is wing-shaped on the projection plane.

According to an embodiment, the transition unit is in the shape of a straight line, and the connecting area is rectangular in cross section; or the transition unit is in a diagonal shape, and the connecting area is trapezoidal in cross section; or the transition unit is It is in the shape of an arc, and the connecting area is spherical in cross section.

According to an embodiment, the sub-winding includes two connection areas, and both ends of the working area are connected to the two connection areas.

According to an embodiment, the current direction in the working area is parallel to the direction of the winding.

According to an embodiment, the coils of the coreless cup winding are mainly wound by enameled wire.

According to an embodiment, the winding includes a first sub-winding, a second sub-winding and a third sub-winding, which are three-phase windings, and the three sub-windings overlap each other.

According to an embodiment, the first working section and the second working section of each turn coil span a radius of π times the arc in the circumferential direction, but is not limited to π times the radius.

According to an embodiment, the length of the padding section of each turn of the coil is smaller than the length of the diagonal section.

According to an embodiment, the winding includes six sub-windings.

According to another aspect of the present application, a manufacturing method applied to the coreless motor winding is provided, including:

Make a winding mold, which includes a crimping head, a winding piece and a base;

Wind the coil along the winding mold to obtain a preliminary winding;

Flip the initial shape winding along the initial round mold to obtain sub-windings;

The sub-windings are spliced to each other on the circumference along the re-circling mold, and the second connecting parts of the sub-windings are filled under the first connecting parts of other sub-windings to form a rotary body to obtain the winding.

According to an embodiment, the resulting primitive winding has no overlapping areas.

According to an embodiment, the initial round mold includes a first cylinder and a second cylinder, the diameter of the first cylinder is larger than the diameter of the second cylinder; a working section of the working area is first attached Close the first cylinder of the initially rounded mold, then fold the connecting area against the second cylinder, and another working section of the working area fits the first cylinder; and, Part of the diagonal segments of the overlapping area overlap.

According to one embodiment, the obtained preliminary winding needs to be semi-thermally cured to ensure that the wires in the working area are bonded to each other while also having a certain degree of freedom, and then the preliminary winding is processed along the preliminary circular mold. The tool is flipped to obtain the sub-winding.

According to an embodiment, the thread pressing head is in a "U" shape.

According to an embodiment, the winding element includes a first winding surface, a V-shaped surface and a second winding surface, and the length of the first winding surface is greater than the length of the second winding surface.

According to an embodiment, the winding member is block-shaped as a whole.

According to another aspect of the present application, a motor with coreless motor windings is provided, including the coreless motor windings.

Description of drawings

Figures 1a and 1b are schematic diagrams of the overall structure of the coreless motor winding of the present application.

Figure 2a is a schematic structural diagram of the filling section of the present application and a structural schematic diagram of the transition unit, bending unit, first working section, second working section and oblique section of each turn coil.

Figure 2b is a schematic structural diagram of the first connecting piece, the second connecting piece and the reserved area.

Figure 2c is a schematic structural diagram of the filling section of the present application and a structural schematic diagram of the transition unit, bending unit, first working section, second working section and diagonal section of each turn coil.

Figures 3a to 3c are schematic diagrams of the overall structure of the windings in different shapes of the transition unit of the present application.

Figures 4a and 4b are schematic diagrams of three sub-windings combined and overlapping each other in the present application, in which A, B and C in Figure 4a respectively represent three-phase currents.

Figures 5a to 5d are schematic diagrams of an embodiment of the present application in which the sub-winding is not provided with an overlapping area and is provided with two connection areas.

Figures 6a to 6g are schematic diagrams of the manufacturing method applied to coreless motor windings of the present application.

FIG. 7 is a schematic flow chart of the manufacturing method of coreless motor windings used in the present application.

Explanation of reference symbols:
1-winding, 2-sub-winding, 21-first sub-winding, 22-second sub-winding, 23-third sub-winding, 3-connection area, 31-filling section, 32-transition unit, 33-bending unit, 331-first connecting piece, 332-second connecting piece, 333-first connection point, 334-second connection point, 335-reserved area, 4-working area, 41-first working section, 42-second Working section, 5-overlapping area, 51-oblique section, 6-primary winding, 7-winding mold, 71-crimping head, 72-winding parts, 721-first winding surface, 722-V-shaped surface, 723-second winding surface, 73-base, 8-initial rounding mold, 81-first cylinder, 82-second cylinder, 9-re-rounding mold, 10-coil.

Detailed ways

The details of one or more embodiments of the application are set forth in the following description of the drawings and embodiments. Other features, objects and advantages of the application can be understood from the description, drawings and claims.

The illustrated and described embodiments are not limited in application to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The illustrated embodiments are capable of other embodiments and of being practiced or carried out in various ways. The examples are provided by way of explanation of the disclosed embodiments, not limitation. Various modifications and variations may be made to the various embodiments of the present application without departing from the scope or spirit of the disclosure. For example, features illustrated or described as part of one embodiment can be used with another embodiment to still produce further embodiments. This disclosure is therefore intended to cover such modifications and variations as come within the scope of the appended claims and their equivalents.

Likewise, the phrases and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "including," "including," or "having" and variations thereof herein is intended to include the items listed thereafter and their equivalents as well as additional items in an open-ended manner.

The present application will be described in more detail below with reference to various embodiments and examples of its various aspects.

In this application, the term "winding" is spliced by "sub-windings", and the term "sub-windings" is obtained by performing an initial rounding of the "primary winding".

Embodiment 1

As shown in Figures 1a and 1b, a coreless motor winding according to an embodiment of the present application is illustrated, including a multi-turn coil 10. The winding 1 includes three sub-windings 2, and the sub-windings 2 include a connection area 3 and a working area 4, the diameter of the connecting area 3 does not exceed the diameter of the working area 4, the working area 4 includes a first working section 41 and a second working section 42, the connecting area 3 at least includes a filling section 31 , both ends of the filling section 31 are respectively connected to the first working section 41 and the second working section 42; and, the first working section 41, the second working section 42 and the filling section 31 of each turn are not the same. Located on the same plane, the filling sections 31 of each turn are not located on the cylindrical surface where the working area 4 is located, and the filling sections 31 of different sub-windings 2 have overlapping areas. Each sub-winding 2 includes a multi-turn coil 10 .

In the first embodiment, the sub-winding 2 also includes an overlapping area 5, which is connected to the working area 4; and the axial length of the connecting area 3 is smaller than the overlapping area 5 axial length, as shown in Figure 1b.

In the first embodiment, the filling section 31 includes a transition unit 32 and a bending unit 33. Both ends of the transition unit 32 are connected to the first working section 41 and the bending unit 33 respectively. The bending unit 33 Both ends of are connected to the second working section 42 and the transition unit 32 respectively; and the axial length of the transition unit 32 is the axial length of the connection area 3, as shown in Figure 2a.

In the first embodiment, the filling section 31 is three-dimensional.

In the first embodiment, the bending unit 33 is arranged to rotate around the center of the winding 1; and the bending unit 33 is at least partially arc-shaped, and all the bending units 33 are combined to form a center in the connection area 3 A reserved area 335 is in the shape of a hole, as shown in Figure 2b.

In the first embodiment, the bending unit 33 includes a first connecting piece 331 and a second connecting piece 332. The first connecting piece 331 is connected to the transition unit 32, and the connecting point between the two is the first connecting point 333. , the second connecting piece 332 is connected to the second working section 42 and the connection point between them is the second connection point 334 .

In the first embodiment, there is a height difference between the first connection point 333 and the second connection point 334; and the position of the first connection point 333 is the extreme end of the winding 1.

In the first embodiment, after all the sub-windings 2 are combined, the first connecting parts 331 of the sub-windings 2 have an overlapping area with the second connecting parts 332 of other sub-windings 2, as shown in Figures 1a and 2b; and, The first working section 41 of the sub-winding 2 has an overlapping area with the second working sections 42 of the other sub-windings 2 .

In the first embodiment, the overlapping area 5 includes a diagonal segment 51, and each turn of the diagonal segment 51 is generally in a "V" shape after unfolding, as shown in Figure 2c.

In the first embodiment, the first connecting member 331 is in the shape of a straight line, and the second connecting member 332 is in the shape of an arc.

In other embodiments, the first connecting member 331 may be in an arc shape, and the second connecting member 332 may be in a linear shape.

In the first embodiment, the transition unit 32 is linear, the transition unit 32 of each turn is located on the same straight line as the first working section 41, and the connection area 3 is rectangular in cross-section, as shown in Figure 3a; Alternatively, the transition unit 32 is in the shape of a diagonal line, and the connection area 3 is in the shape of a trapezoid in cross section, as shown in Figure 3b; or the transition unit 32 is in the shape of an arc, and the connection area 3 is in the shape of a trapezoid in cross section. Spherical shape, as shown in Figure 3c.

In the first embodiment, the current direction of the working area 4 is parallel to the direction of the winding 1 .

In the first embodiment, the coil 10 of the winding 1 is mainly made of enameled wire.

In the first embodiment, the winding 1 includes a first sub-winding 21, a second sub-winding 22, and a third sub-winding 23. As shown in Figures 4a and 4b, the three are three-phase windings, and the three sub-windings 2 are interconnected with each other. Overlapping, the winding 1 has two layers of working area 4.

In the first embodiment, the first working section 41 and the second working section 42 of each turn coil 10 span a radius of π times the arc in the circumferential direction, but is not limited to a radius of π times, as shown in Figure 2c.

In the first embodiment, the length of the padding section 31 of each turn coil 10 is shorter than the length of the oblique section 51 .

Embodiment 2

The second embodiment is generally the same as the first embodiment, except that the sub-winding 2 is not provided with an overlapping area 5 .

As shown in Figures 5a to 5d, a coreless motor winding is illustrated, including a multi-turn coil 10. The winding 1 includes three sub-windings 2, and the sub-windings 2 include a connection area 3 and a working area 4. The diameter of the connecting area 3 does not exceed the diameter of the working area 4. The working area 4 includes a first working section 41 and a second working section 42. The connecting area 3 at least includes a filling section 31. The filling section 31 Both ends are connected to the first working section 41 and the second working section 42 respectively; and the first working section 41, the second working section 42 and the filling section 31 of each turn are not located on the same plane, and each turn The filling sections 31 are not located on the cylindrical surface where the working area 4 is located, and the filling sections 31 of different sub-windings 2 have overlapping areas.

In the second embodiment, the sub-winding 2 includes two connection areas 3, and the two connection areas 3 are respectively connected to both ends of the working area 4, as shown in Figure 5c.

In the second embodiment, the bending unit 33 is arc-shaped as a whole, as shown in Figure 5d.

In the second embodiment, when the bending unit 33 is in the shape of an arc as a whole, the bending unit 33 is in the shape of a wing on the projection plane.

In this regard, the relevant structure and concept of Embodiment 2 are similar to Embodiment 1, and therefore will not be described again here.

Embodiment 3

The manufacturing method of coreless motor windings of this application, as shown in Figure 7, includes the following steps.

Step 1: Make the winding mold 7. The winding mold 7 includes a crimping head 71, a winding member 72 and a base 73, as shown in Figures 6a and 6b.

Step 2: Wind the coil along the winding mold 7 to obtain the preliminary winding 6, as shown in Figures 6c and 6d.

Step 3: Flip the preliminary winding 6 along the initial round mold 8 to obtain the sub-winding 2, as shown in Figure 6e.

Step 4: Connect the sub-windings 2 to each other on the circumference along the re-circling mold 9, and fill the second connecting parts 332 of the sub-windings 2 below the first connecting parts 331 of other sub-windings 2 to form The rotating body obtains winding 1, as shown in Figures 6f and 6g.

In the third embodiment, the primary winding 6 obtained in step 2 has no overlapping area, as shown in Figure 6d.

In the third embodiment, in the step 3, the initial round mold 8 includes a first cylinder 81 and a second cylinder 82. The diameter of the first cylinder 81 is larger than that of the second cylinder 82. diameter; a working section of the working area 4 first fits the first cylinder 81 of the initial round mold 8, and then the connecting area 3 is folded against the second cylinder 82. Another working section of Zone 4 fits the The first cylinder 81; and, part of the oblique segments 51 of the overlapping area 5 overlap.

In the third embodiment, the thread pressing head 71 is in a "U" shape.

In the third embodiment, the winding member 72 includes a first winding surface 721, a V-shaped surface 722 and a second winding surface 723. The length of the first winding surface 721 is longer than that of the second winding surface. 723 length.

In the third embodiment, the winding member 72 is block-shaped as a whole.

Embodiment 4

A motor with coreless motor windings includes the coreless motor windings. The motor produced by this winding 1 has better motor performance. Among them, in addition to the coreless motor windings, the motor also includes components such as the rotor. The rotor is at least partially disposed within the coreless motor windings.

The technical solution of this application includes the following effects:

1. The ends of the coreless cup windings in the related art are large in size and have low space utilization, which is not conducive to motor miniaturization. Moreover, the end windings are rhombus windings, oblique windings or hexagonal windings, and the ends account for 10% of the entire winding. The ratio is large and the actual working section is short, which is not conducive to the output torque of the motor. The torque constant is small and the heat generation is large. However, the technical solution of this application avoids the above problems. The coreless cup motor winding of this application includes at least three sub-windings. It includes a connecting area and a working area. The diameter of the connecting area does not exceed the diameter of the working area. The connecting area is arranged inward, which does not increase the diameter of the winding and avoids the problem of reducing the space utilization of the micro motor. On the other hand, the working area The area includes the first working section and the second working section, and the connection area includes filling sections. After different sub-windings are combined, their filling sections overlap each other, filling the space not occupied by the filling sections of other sub-windings, which is equivalent to converting the originally axial The winding ends are arranged in the radial direction, thereby reducing the axial length of the connection area. Considering the overall length of the winding, it actually increases the length of the working area, increases the torque constant, improves the heating situation, and improves the work efficiency. efficiency.

2. According to a concept of this application, the sub-winding includes a connection area, a working area and an overlapping area. Since the filling section of the connection area is three-dimensional, the first working section, the second working section and the filling section of each turn are three-dimensional. The two are not located on the same plane, so the connection area will not only occupy the axial length, but also the radial space. Therefore, the axial length of the connection area is smaller than the axial length of the overlapping area, reducing the overall length of the winding, or It is said that increasing the axial proportion of the working area in the winding is beneficial to improving the efficiency of the coreless motor.

3. According to a concept of this application, the filling section includes a transition unit and a bending unit, and the bending unit is at least partially arc-shaped, so that after all the sub-windings are combined, a reserved area is formed in the center of the connection area, and the bending unit will not be completely filled. The connection area is full, and the reserved area is hole-shaped, providing rotation space for the motor rotor.

4. According to a concept of this application, the bending unit includes a first connecting piece and a second connecting piece. The first connecting piece is connected to the transition unit, and the second connecting piece is diametrically connected to the second working section. Since the transition unit is axially connected Located at the end of the work area, the connection point between the first connecting piece and the transition unit is smaller than the connection point between the second connecting piece and the transition unit. The connection point of the second working section is further located at the end of the winding, that is, the first connection point is located further at the end of the winding than the second connection point. Therefore, due to the height difference between the first connection point and the second connection point, different sub-windings are located at the end of the winding. After combination, their connection areas can overlap each other, and the first connecting piece overlaps with the second connecting piece of other sub-windings, which improves the space utilization of the windings and also achieves the goal of minimizing the axial length of the connecting area. The function of the lower connection area.

The foregoing description of various embodiments of the present application has been presented for purposes of illustration. The foregoing description is not intended to be exhaustive or to limit the application to the precise arrangements, construction and/or steps disclosed, and many modifications and variations are possible in light of the above teachings. The scope of the application and all equivalents thereto are intended to be defined by the appended claims.

Claims

A coreless motor winding includes a multi-turn coil, wherein the winding includes at least two sub-windings, the sub-windings include a connecting area and a working area, the diameter of the connecting area does not exceed the diameter of the working area, so The working area includes a first working section and a second working section, the connecting area includes a filling section, and both ends of the filling section are connected to the first working section and the second working section respectively; and, each The first working section, the second working section and the filling section of the turn coil are not located on the same plane, the filling section of each turn coil is not located on the cylindrical surface where the working area is located, and the filling sections of different sub-windings have overlapping areas.
The coreless motor winding according to claim 1, wherein the sub-winding further includes an overlapping area connected to the working area; and the axial length of the connecting area is smaller than the overlapping area. The axial length of the winding zone.
The coreless motor winding according to claim 1, wherein the filling section includes a transition unit and a bending unit, and both ends of the transition unit are connected to the first working section and the bending unit respectively, and the bending unit Both ends of the unit are connected to the second working section and the transition unit respectively; and the axial length of the transition unit is the axial length of the connection area.
The coreless motor winding according to claim 3, wherein the bending unit is arranged to rotate around the center of the winding; and the bending unit is at least partially arc-shaped, and all bending units are combined in the connection area The center forms a reserved area.
The coreless motor winding according to claim 3, wherein the bending unit includes a first connecting piece and a second connecting piece, the first connecting piece is connected to the transition unit and the connection point between the two is a first connecting piece. Connection point, the second connecting piece is connected to the second working section and the connection point between the two is the second connection point.
The coreless motor winding according to claim 5, wherein there is a height difference between the first connection point and the second connection point; and the position of the first connection point is the extreme end of the winding. .
The coreless motor winding according to claim 5, wherein after all the sub-windings are combined, the first connecting piece of the sub-winding has an overlapping area with the second connecting piece of other sub-windings; and, the first connecting piece of the sub-winding has an overlapping area; One working section has an overlapping area with the second working section of other sub-windings.
The coreless motor winding according to claim 2, wherein the overlapping area includes a diagonal segment, and the diagonal section of each turn forms a "V" shape when expanded.
The coreless motor winding according to claim 5, wherein the bending unit is in the shape of an arc; or, the first connecting piece is in the shape of a straight line, and the second connecting piece is in the shape of an arc.
The coreless motor winding according to claim 5, wherein the transition unit is in the shape of a straight line, and the connecting area is rectangular in cross section; or, the transition unit is in a diagonal shape, and the connecting area is in a rectangular shape in cross section. It is trapezoidal; or, the transition unit is arc-shaped, and the connecting area is spherical in cross-section.
The coreless motor winding according to claim 1, wherein the sub-winding includes two connection areas, and both ends of the working area are connected to the two connection areas.
A manufacturing method applied to the coreless cup motor winding according to any one of claims 1 to 11, including:

Making a winding mold, wherein the winding mold includes a crimping head, a winding piece and a base;

Wind the coil along the winding mold to obtain a preliminary winding;

Flip the initial shape winding along the initial round mold to obtain sub-windings;

The sub-windings are spliced to each other on the circumference along the re-circling mold, and the second connecting parts of the sub-windings are filled under the first connecting parts of other sub-windings to form a rotary body to obtain the winding.
The manufacturing method of claim 12, wherein the primary winding has no overlapping area.
The manufacturing method according to claim 12, wherein the initial round mold includes a first cylinder and a second cylinder, the diameter of the first cylinder is larger than the diameter of the second cylinder; the working One working section of the working area first fits the first cylinder of the initially rounded mold, and then the connecting area is folded against the second cylinder, and the other working section of the working area fits the The first cylinder; and, some oblique segments of the overlapping area overlap.
A motor with a coreless motor winding, including a rotor and the coreless motor winding according to any one of claims 1 to 11, the rotor being at least partially disposed within the coreless motor winding.