Manufacturing method of stator for slotless electric motor
Patent Information
- Application Number
- JP2023005779
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-01-19
- Filing Date
- 2023-01-18
- Publication Date
- 2026-01-22
AI Technical Summary
Existing methods for manufacturing slotless motors are time-consuming and costly, and they often require multiple steps to form and join individual conductor coils, leading to conductor loop disturbances and circulation losses.
A method for manufacturing a slotless motor stator involves arranging conductors in an annular cylindrical shape, forming multiple joints with reduced spacing, and folding them into petals, which are then aligned and bonded with a bonding compound, allowing for a single formation process that reduces the need for additional welding and minimizes circulation losses.
This method significantly reduces manufacturing time and costs while enhancing conductor density and power transfer efficiency, resulting in a stator with improved current flow and reduced temperature rise.
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Abstract
Description
[Technical Field]
[0001] This application relates to a slotless electric motor, and more particularly to a method for manufacturing a stator for a slotless electric motor. [Background technology]
[0002] An electric motor is an electromagnetic device that converts electrical energy into kinetic energy. A motor consists of two parts: a stator and a rotor. A slotless motor is a type of motor known in the art. [Overview of the project] [Problems that the invention aims to solve]
[0003] Unfortunately, the prior art methods for manufacturing slotless motors are time-consuming and / or costly.
[0004] Unfortunately, several typical prior art methods for manufacturing stators for slotless motors require a secondary step after the conductor coils have been formed, in which all the individual conductor coils are joined together. That is, a primary process of forming the conductors into a predetermined shape (e.g., a predetermined geometric shape) is performed multiple times for multiple conductor coils. After a predetermined number of primary processes (e.g., N times), the individual conductor coils (e.g., N conductor coils) are joined together (e.g., via N-1 connectors), and a stator for a slotless motor is provided.
[0005] Unfortunately, some typical prior art methods for manufacturing stators for slotless motors form the stator from a single conductor, but involve compressing the conductor into a predetermined shape (e.g., a predetermined geometric shape) to form multiple loops (e.g., thereby omitting the N-1 connections described in the paragraph above), which may result in a stator with disordered lengths of conductors forming the loops (e.g., intersecting and / or non-parallel). Disorder in the conductor loops arises from winding circulating losses. [Means for solving the problem]
[0006] Aspects of the present invention are described in independent claims, and any features are described in dependent claims. Aspects of the present disclosure may be provided in relation to one another, and features of one aspect may be applied to other aspects.
[0007] One aspect of the present disclosure provides a method for manufacturing a stator for a slotless electric motor. The method comprises the steps of arranging a conductor in an annular cylindrical shape, joining a plurality of joints of the conductor, and bending the conductor to provide a plurality of repeating petal-shaped sections along the conductor. The joints include a region of the conductor where adjacent wires are joined along the joint and the average distance between adjacent wires at the joint is smaller than at the non-joints, and the plurality of joints are separated by non-joints. Each petal-shaped section includes a pair of joints connected by non-joints, the pair of joints being arranged parallel to each other. Adjacent petal-shaped sections on the conductor are connected by non-joints. The non-joints of the petal-shaped sections are bundled by the circumference of a first circle having a first diameter. The non-joints connecting the petal-shaped sections are bounded by the circumference of a second circle having a second diameter, which is smaller than the first diameter, and the first and second circles are coplanar and concentric. By rotating each petal-like part around a point on the second circle and aligning the joints of all the petal-like parts in parallel, a stator is provided that includes a cylindrical conductor having a diameter equal to the second diameter, with the joints positioned around the central longitudinal axis of the cylindrical conductor and equidistant from the central longitudinal axis.
[0008] Advantageously, a method for manufacturing a stator for a slotless motor is provided that takes less time than the manufacturing methods of prior art.
[0009] The conductor may constitute at least a portion of the motor's stator.
[0010] In the embodiment, the method for manufacturing the stator may include the step of providing a wave-shaped winding. Advantageously, the wave-shaped winding can provide a stator with a relatively large conductor volume with a relatively small number of soldering / welding processes for providing the conductor. Advantageously, the wave-shaped winding can provide a stator with reduced circulation / vortex losses.
[0011] In the embodiment, the annular cylinder (also called a cylinder) may have an inner radial surface, an outer radial surface, a first axial surface, a second axial surface, and a central longitudinal axis.
[0012] In the embodiment, the conductor comprises a bundle of wires. Each wire may be arranged parallel to adjacent wires (for example, without twists or knots formed between the wires).
[0013] In the example where the conductor is wound helically around a central longitudinal axis, each wire of the conductor is at a constant distance from the inner radial plane.
[0014] In the example where the conductor is wound helically around a central longitudinal axis, each wire of the conductor is at a constant distance from the first axial plane.
[0015] The step of joining multiple joints on a conductor may include, for example, applying a bonding compound (e.g., an adhesive such as a resin or wax) along the length of the conductor to form multiple joints, and the step of joining multiple joints on a conductor further includes activating the bonding compound (e.g., solidifying the resin or wax).
[0016] In cases where the bonding compound is a wax, the wax can be melted and applied to the conductive portion. The waxed portion can be compressed while allowing it to cool until it hardens. In this regard, "activating" the wax may include cooling it so that it hardens.
[0017] As an example, the bonding compound is a wax such as molding wax. The molding wave is applied to the conductor portion, compressed, and then baked (i.e., the wax is "activated") during the potting process.
[0018] Advantageously, a simple means of providing a plurality of joints can be provided, for example, welding etc. may not be required. Advantageously, for example, the time required for manufacturing / assembly is shortened. Instead of performing a method of forming individual conductors into a specific shape multiple times and then joining (e.g., welding) these individual conductors together, the manufacturing method can be used once to form a cylindrical shape.
[0019] This method may include adding a half twist to one of the non - joined portions of the conductor such that the cross - section of the wire at the first point of the conductor is a mirror image of the cross - section of the wire at the second point of the conductor, i.e., the wire on the inner radial plane at the first point is on the outer radial plane at the second point.
[0020] Advantageously, the Joule heating of the conductor can be distributed between the first portion of the conductor on the first side of the half twist and the second portion of the conductor on the second side of the half twist. Thus, the wear associated with heating can be dispersed on both sides, thereby extending the life of the conductor.
[0021] This method may include placing a cylindrical conductor within a central hole of a flux ring having an inner diameter larger than the second diameter, thereby providing a stator including a cylindrical conductor having a flux ring disposed around the outer radial surface of the conductor.
[0022] The flux ring may have an axial length that is at least the length of the joint of the conductor. Advantageously, the power transmission from the stator to the rotor can be increased compared to the case where a shorter flux ring is used.
[0023] This method can include disposing an expandable mandrel at the center of a cylindrical conductor and expanding the expandable mandrel when the cylindrical conductor is disposed within the central hole of a flux ring, thereby increasing the diameter of the cylindrical conductor to a diameter between a second diameter and the inner diameter of the flux ring.
[0024] In an embodiment, a plurality of folded conductors (e.g., conductors formed by steps of folding a conductor to provide a plurality of lobes repeated along the conductor, as detailed above) are stacked on top of each other (e.g., the first and second circles of each conductor are arranged overlapping each other, and respective lobes are aligned). Subsequent method steps are performed on the plurality of conductors as a whole.
[0025] Advantageously, the radial distance between the conductor and the flux ring can thereby relatively increase the power transmission between the conductor (e.g., stator) and the rotor. In an example where a plurality of folded conductors are stacked on top of each other, the folded conductors are stacked at a selected preferred height. The stack height is the axial extent of the stacked conductors. At a preferred stack height, the copper density is improved, enabling a large current to flow with relatively low power loss. Bringing the stack of folded conductors closer to the preferred stack height reduces the radial distance between the conductor and the magnetic flux ring.
[0026] This method may include bending a first axial end of the cylindrical conductor toward the longitudinal axis.
[0027] The first axial end is disposed in contact with a heat sink, thereby assisting heat transfer from the stator. In an example, the second axial end may be disposed in contact with the heat sink.
[0028] Advantageously, the average axial distance between the flux ring and the first axial end of the conductor can be shortened, thereby increasing the power transmission between the stator and the rotor. Power loss (I 2A decrease in R reduces the temperature rise of the conductor when current flows. By suppressing the temperature rise of the conductor, a larger torque can be applied to the motor (the motor's rotational speed can be increased).
[0029] This method may include bending the second axial end of the cylindrical conductor away from the longitudinal axis.
[0030] Providing at least one axial end (in this example, the second axial end) away from the longitudinal axis allows the rotor to be inserted into the stator, i.e., the rotor can be positioned between the inner radial surfaces formed by the cylindrical conductor.
[0031] One aspect of the present disclosure provides a method for manufacturing a stator for a slotless electric motor. The method includes the steps of arranging a conductor in a semi-annular manner within the boundary of an annular cylinder, and half-twisting one of the non-joints of the conductor such that the cross-section of the wire at a first point of the conductor is a mirror image of the cross-section of the wire at a second point of the conductor. Multiple joints on the conductor are joined, the joints constituting a region of the conductor where the wires within the region are joined together, and the multiple joints are separated by non-joints. The cross-section of the wire at the first point of the conductor is a mirror image of the cross-section of the wire at the second point of the conductor such that the wire on the inner radial plane at the first point is on the outer radial plane at the second point.
[0032] Advantageously, a method for manufacturing a stator for a slotless motor is provided that takes less time than the manufacturing methods of prior art.
[0033] In the example, the annular cylinder (also called a cylinder) may have an inner radial surface, an outer radial surface, a first axial surface, a second axial surface, and a central longitudinal axis.
[0034] In the embodiment, the conductor includes a bundle of wires. Each wire may be arranged parallel to adjacent wires (for example, without twists or knots formed between the wires).
[0035] In the example where the conductor is wound spirally around a central longitudinal axis, each wire of the conductor is at a constant distance from the radially inner surface.
[0036] In the example where the conductor is wound helically around a central longitudinal axis, each wire of the conductor is at a constant distance from the first axial plane.
[0037] One aspect of this disclosure provides a stator for a slotless electric motor obtained by any of the methods described herein.
[0038] Advantageously, a stator for a slotless motor is provided that takes less time to manufacture than slotless motors manufactured using prior art methods.
[0039] One aspect of the present disclosure provides a method for manufacturing a slotless electric motor, the method comprising the steps of: performing one of the methods for manufacturing a stator described herein, thereby providing a stator; and providing a rotor configured to rotate around the axial center of the stator.
[0040] Advantageously, a method for manufacturing a stator for a slotless motor is provided that takes less time than the manufacturing methods of prior art.
[0041] One aspect of the present disclosure provides a stator for a slotless electric motor, the stator being a conductor comprising a bundle of wires, each wire being arranged parallel to the other wires, the conductor comprising a plurality of joints, each joint comprising a region of the conductor where adjacent wires are joined along the joint, the average spacing between adjacent wires at the joint being smaller than at the non-joints, and the non-joints separating the plurality of joints.
[0042] A joint is sometimes called a chocolate block. Advantageously, a joint provides a region with increased conductor density compared to the unjointed area. Correspondingly, the joined region can allow a relatively high current density to pass through it, which can generate a stronger magnetic field (e.g., closer field lines) around the joint compared to the unjointed area. In the example where the conductor is copper, the joint provides a region with increased copper density, known as copper-filled or copper-filled density.
[0043] The joint has greater rigidity (e.g., greater stiffness) than the non-jointed area. That is, when the same magnitude of force is applied to both the joint and the non-jointed area, the joint deforms to a smaller extent than the non-jointed area. Considering the relative stiffness of the joint, the joint may support the structure of the stator (e.g., the stator is self-supporting due to the joint).
[0044] The conductors may be arranged in a cylindrical shape. The conductor joints are arranged parallel to each other and on the circumference of a circle, and the joints are arranged around the central longitudinal axis of the cylindrical conductor and equidistant from the central longitudinal axis. The conductor joints are cylindrical. [Brief explanation of the drawing]
[0045] [Figure 1] This is a plan view of a conductor. [Figure 2A] A plan view of the conductor in the axial direction. [Figure 2B] This is an axial plan view of a portion of the conductor in Figure 2A. [Figure 3A] Figures 2A and 2B are axial plan views of the conductor, which has multiple joints and non-joints. [Figure 3B] This is an axial plan view of the conductor layer at the non-jointed section. [Figure 3C] This is an axial plan view of the conductor layer at the joint. [Figure 4A] This figure shows the conductors shown in Figures 3A, 3B, and 3C, folded to provide multiple petal-like sections. [Figure 4B]This figure shows the conductors shown in Figures 3A, 3B, and 3C, folded to provide multiple petal-like sections. [Figure 5A] This figure shows another conductor similar to the first conductor shown in Figures 3A, 3B, and 3C, folded to provide multiple petal-like parts. [Figure 5B] This figure shows another conductor similar to the first conductor shown in Figures 3A, 3B, and 3C, folded to provide multiple petal-like parts. [Figure 6A] This figure shows another conductor similar to the first conductor shown in Figures 3A, 3B, and 3C, folded to provide multiple petal-like parts. [Figure 6B] This figure shows another conductor similar to the first conductor shown in Figures 3A, 3B, and 3C, folded to provide multiple petal-like parts. [Figure 7A] This is an axial view showing a first folded conductor, a second folded conductor, and a third folded conductor stacked axially to provide a folded conductor stack. [Figure 7B] Figure 7A shows a radial view of the folded conductor stack. [Figure 8A] This diagram shows the joint in the first part of the conductor. [Figure 8B] This diagram shows the joint in the second part of the conductor. [Figure 9] This is a perspective view showing a half-twist in the non-jointed portion of a conductor. [Figure 10A] This figure shows a series of steps to form the stator core shown in Figure 11 by rotating the set of petal-shaped parts of the folded conductor shown in Figure 7A. [Figure 10B] This figure shows a series of steps to form the stator core shown in Figure 11 by rotating the set of petal-shaped parts of the folded conductor shown in Figure 7A. [Figure 10C] This figure shows a series of steps to form the stator core shown in Figure 11 by rotating the set of petal-shaped parts of the folded conductor shown in Figure 7A. [Figure 11]Figures 7A and 7B show cylindrical conductors formed from laminated conductors. [Figure 12] This is an axial view showing a cylindrical conductor for the stator. [Figure 13] This is a flowchart showing a method for manufacturing a stator for a slotless electric motor. [Modes for carrying out the invention]
[0046] Here, we will describe a method for manufacturing a stator for a slotless motor. The stator may be a radial flux stator, but it will be understood that other types of stators may also be used. In short, a conductor is provided that includes wires forming the foundation of the stator. Parts of the conductor are joined to provide multiple joints that function as stator coils in the assembled stator. The conductor is manipulated in a novel and ingenious way to provide a conductor in which all wires have the same circumferential average position and all the same radially average positions of the wires are equal, thereby providing the stator.
[0047] Figure 1 is a plan view showing the conductor 100.
[0048] The conductor 100 comprises a bundle of wires (for example, multiple wires) in which each wire is arranged parallel to the other wires.
[0049] A method for manufacturing a stator for a slotless electric motor includes the step of arranging a conductor in the shape of an annular cylinder, the annular cylinder having an inner radial surface, an outer radial surface, a first axial surface, and a second axial surface, and the conductor comprises a bundle of wires, each wire arranged parallel to the other wires, and each wire arranged at a certain distance from the inner radial surface.
[0050] Figures 2A and 2B show the conductor shown in Figure 1 arranged in the shape of an annular cylinder, as described in the method steps above.
[0051] Figure 2A is an axial plan view of the conductor. Figure 2B is an axial plan view of a portion of the conductor in Figure 2A.
[0052] The conductor 100 is formed in an annular cylindrical shape surrounding a central longitudinal axis X. That is, the conductor 100 is wound helically around the central longitudinal axis, forming an annular cylindrical shape overall. The conductor 100 has multiple loops around the central longitudinal axis. In this example, there are four loops, i.e., the conductor makes four complete turns around the central longitudinal axis X. The four loops are the first loop 121, the second loop 122, the third loop 123, and the fourth loop 124. The multiple loops 121-124 are arranged parallel to and adjacent to each other. When the conductor 100 is wound around the central longitudinal axis, the wires forming the conductor have a helical shape, i.e., the wires have multiple turns around the central longitudinal axis. Each wire of the conductor is positioned at a certain distance from the first axial plane, and each wire is positioned at a certain distance from the inner radial plane. The conductor 100 has two ends that provide a connection portion 120 for connecting the conductor to an electromotive force source.
[0053] As described above, the conductor 100 is arranged in an annular cylindrical shape. The annular cylinder comprises a central longitudinal axis X, an inner radial surface 151 having an inner radius RI (i.e., the distance from the central longitudinal axis to the inner radial surface 151), an outer radial surface 152 having an outer radius RO, a first axial surface 153, and a second axial surface 154.
[0054] The inner radial surface 151 is positioned adjacent to the first axial surface 153 and the second axial surface 154. The outer radial surface 152 is positioned adjacent to the first axial surface 153 and the second axial surface 154. The first axial surface 153 is positioned adjacent to the inner radial surface 151 and the outer radial surface 152. The second axial surface 154 is positioned adjacent to the inner radial surface 151 and the outer radial surface 152. The first axial surface 153 is perpendicular to the inner radial surface 151 and the outer radial surface 152, and parallel to the second axial surface 154. The first axial surface 153 and the second axial surface 154 are positioned in the direction of the longitudinal axis X, and the inner radial surface 151 is perpendicular to the first axial surface 153 and the second axial surface 154. The inner radial surface 151 and the outer radial surface 152 are positioned perpendicular to the longitudinal axis X.
[0055] Although the conductor 100 is continuous, each loop (i.e., a complete turn of the conductor around the central longitudinal axis) can be considered as a discrete integer. The first end of the first loop 121 is configured to connect to an electromotive force (EMF) source. The second end of the first loop 121 is connected to the first end of the second loop 122. The second end of the second loop 122 is connected to the first end of the third loop 123. The second end of the third loop 123 is connected to the first end of the fourth loop 124. The second end of the fourth loop 124 is configured to connect to the EMF source.
[0056] More specifically, and as can be seen in Figure 2B, the first loop 121 is positioned parallel to and adjacent to the second loop 122, the second loop 122 is positioned parallel to the first loop 121 and the third loop 123, the third loop 123 is positioned parallel to the second loop 122 and the fourth loop 124, and the fourth loop 124 is positioned parallel to and adjacent to the third loop 123. The connecting section 120 comprises the first end of the first loop and the second end of the fourth loop.
[0057] To reduce voltage and / or current asymmetry between any of loops 121 to 124, a circulating current may be supplied around the stator.
[0058] In this example, the conductor 100 is composed of 15 layers of wires. Therefore, the conductor has a thickness of 15t w and t w is the thickness of one wire. Thus, each of the loops has a thickness of 15t w Each layer has a width of five wires. Therefore, the conductor has a width of 5w w and w w is the width of one wire. From this, it can be seen that each loop has a thickness of 15t w and a width of 5w w .
[0059] In the example described in this specification, each wire has a circular cross-section (for example, each wire is a cylindrical tube), each wire has the same diameter, and the thickness and width are equal to the diameter of the circular cross-section, and t w = w w .
[0060] The first layer of the wires of the conductor (LAYER1 in FIG. 2B) is arranged on the inner radial surface 151. That is, the first layer is arranged at zero spacing from the inner radial surface. The second layer (LAYER2 in FIG. 2B) is separated from the inner radial surface 151 by one layer (that is, the first layer LAYER1). In other words, the second layer is arranged at a distance equal to the thickness t w of one wire from the inner radial surface 151. Similarly, the third layer (LAYER3 in FIGS. 3B to 3C) is arranged at a distance of 2t w and so on. The 15th layer (LAYER15 in FIG. 2B) is separated from the inner radial surface 151 by 14 layers of wires. In other words, the 15th layer is arranged at a distance equal to the thickness 14t w of 14 wires from the inner radial surface 151. The 15th layer is arranged on the outer radial surface 152, that is, the 15th layer is arranged at zero spacing from the outer radial surface 152.
[0061] Each of the loops 121 to 124 extends from the inner radial surface 151 to the outer radial surface 152. The surface of the first loop 121 is located in the first axial surface 153; that is, loop 121 forms the first axial surface 153. The surface of the fourth loop 124 is located in the second axial surface 154; that is, loop 124 forms the second axial surface 154.
[0062] A method for manufacturing a stator for a slotless electric motor includes the step of joining multiple joints on a conductor, where each joint includes a region of the conductor along which adjacent wires are joined, the average spacing between adjacent wires is smaller at the joints than at the non-joints, and the multiple joints are separated by the non-joints.
[0063] Figure 3A shows the conductor shown in Figures 2A and 2B, which has multiple joints and multiple non-joints, as described in the method steps above.
[0064] Figure 3A shows an axial plan view of the conductors of Figures 2A and 2B, including multiple joints and non-joints; Figure 3B shows an axial plan view of the conductor layers at the non-joints; and Figure 3C shows an axial plan view of the conductor layers at the joints.
[0065] The cylindrical conductor 100 includes a plurality of non-joints 301 and a plurality of joints 302. The average spacing between wires in adjacent layers is smaller at the joints 302 than at the non-joints 301. In other words, the joints 302 have a higher density than the non-joints 301. The conductor density of the joints 302 is greater than the conductor density of the non-joints 301. In the example where the conductor is formed of copper, the joints 301 have a larger copper filling than the non-joints.
[0066] The non-joint portion 301 may have a shorter length than the joint portion 302.
[0067] The joint 302 is provided by applying a bonding compound to a portion of the conductor 100 and compressing the portion to which the bonding compound is applied until the bonding compound hardens.
[0068] For example, the bonding compound is an adhesive such as a resin, such as a thermoactivated resin or a photoactivated resin (for example, an ultraviolet activated resin). In the case of using a thermoactivated resin, heat may be applied by a clamping device to compress the part to which the adhesive is applied, or by passing an electric current through a conductor to heat the length of the conductor to which the adhesive is applied (e.g., Joule heating), heating the clamping device to heat the length of the conductor to which the adhesive is applied, or irradiating the length of the conductor to which the adhesive is applied with infrared light.
[0069] A method for manufacturing a stator for a slotless electric motor includes the step of bending a conductor to provide a plurality of petal-shaped sections repeated along the conductor, each petal-shaped section including a pair of joints connected by non-joints, the pair of joints being arranged parallel to each other, adjacent petal-shaped sections on the conductor being connected by non-joints, the non-joints in the petal-shaped sections being bounded by the circumference of a first circle having a first diameter, the non-joints connecting the petal-shaped sections being bounded by the circumference of a second circle having a second diameter, the second diameter being smaller than the first diameter, and the first and second circles being coplanar and concentric.
[0070] Figures 4A and 4B show the conductor shown in Figures 3A, 3B, and 3C (i.e., the first conductor) folded to provide multiple petal-like structures, as described in the method steps above. Figures 5A and 5B show another conductor similar to the first conductor shown in Figures 3A, 3B, and 3C (i.e., the second conductor) folded to provide multiple petal-like structures, as described in the method steps above. Figures 6A and 6B show another conductor similar to the first conductor shown in Figures 3A, 3B, and 3C (i.e., the third conductor) folded to provide multiple petal-like structures, as described in the method steps above.
[0071] Figure 4A shows an axial view of a folded conductor 400 having multiple petal-like parts 410 and connecting petal-like parts 420, and Figure 4B shows a radial view of the folded conductor 400 shown in Figure 4A. Figure 5A shows an axial view of a folded conductor 400' having multiple petal-like parts 410' and connecting petal-like parts 420', and Figure 5B shows a radial view of the folded conductor 400' shown in Figure 5A. Figure 6A shows an axial view of a folded conductor 400'' having multiple petal-like parts 410'' and connecting petal-like parts 420'', and Figure 4B shows a radial view of the folded conductor 400'' shown in Figure 4A. Adjacent petal-like parts form a 45-degree angle with the central longitudinal axis (i.e., ∠petal-like part-axis-petal-like part = 45°).
[0072] Each petal-shaped portion 410 has a pair of joints 302 connected by a non-joint 301. The pair of joints in the petal-shaped portion 410 are arranged parallel to each other. Adjacent petal-shaped portions 410 of the conductor are connected by the non-joint 301.
[0073] The connecting petal-like portion 420 is similar to the petal-like portion 410, but is further provided with a connecting portion 120.
[0074] The unjointed portions 301 in the petal-like parts 410 and 420 are surrounded by the circumference of the first circle 451, which has a first diameter; that is, the unjointed portions 301 in the petal-like parts are located outside the circumference of the first circle 451.
[0075] The non-joint portions connecting adjacent petal-like parts are bounded by the circumference of the second circle 452, which has a second diameter, and the second diameter is smaller than the first diameter; that is, the non-joint portions connecting the petal-like parts are located within the circumference of the second circle 452.
[0076] The first circle 452 and the second circle 452 are coplanar and concentric. The first circle 451 and the second circle 452 are arranged on the same plane, which is referred to herein as the circular plane. The first circle 451 and the second circle 452 have their centers on the central longitudinal axis X of the conductor 100.
[0077] The second folded conductors shown in Figures 5A and 5B have the same characteristics as the first folded conductors, which are represented by the same notation with a single prime symbol added; that is, the second folded conductors have features such as multiple petal-like portions 410' and connecting petal-like portions 420'. Similarly, the third folded conductor has the same characteristics as the first folded conductor and is represented by the same notation with a double prime symbol added (that is, the third folded conductor has multiple petal-like portions 410'' and connecting petal-like portions 420'').
[0078] The first circle 451 and the second circle 452 of the first conductor 400 are identical to the first circle 451' and the second circle 452' of the second conductor 400'. The first circle 451 and the second circle 452 of the first conductor 400 are identical to the first circle 451' and the second circle 452'' of the third conductor 400''.
[0079] Figure 7A is an axial view of the first folded conductor 400, the second folded conductor 400', and the third folded conductor 400'', which are stacked axially on top of each other to provide a folded conductor stack 500, and Figure 7B is a radial view of the folded conductor stack 500 shown in Figure 7A.
[0080] When the first conductor 400, the second conductor 400', and the third conductor 400'' are folded in the manner described herein to provide a petal-like structure, the three conductors are then stacked one on top of the others. That is, the axial surface of the first conductor 400 is substantially in contact with the axial surface of the second conductor 400', and another axial surface of the second conductor 400' is substantially in contact with the axial surface of the third conductor. The central longitudinal axes of the first, second, and third conductors are aligned and coincide.
[0081] The method for forming the stator may include stacking multiple (preferably three) folded conductors 500 one by one in the axial direction.
[0082] Hereinafter, a set of petal-shaped parts including the petal-shaped parts from the first folded conductor 400, the second folded conductor 400', and the third folded conductor 400'' will be referred to as a petal-shaped part set 510. Each petal-shaped part set 510 includes two sets of connecting parts 602 and one set of non-connecting parts 601. Each petal-shaped part set 510 is connected by one set of non-connecting parts. The petal-shaped part sets included in the connecting petal-shaped parts of the first, second, and third conductors will be referred to as a connecting petal-shaped part set 520. The non-connecting parts 601 of each petal-shaped part set 510 are positioned on the first circle 551 (the first circle 551 is the same as the first circles 451, 451', and 451''). Each set of non-jointing portions 601 connecting each petal-shaped portion set 510 is positioned on the second circle 552 (the second circle 552 is identical to the second circles 452, 452', and 452'').
[0083] The first, second, and third conductors are folded such that the joints in each petal-shaped section are offset from one another. As a result of this offset, when stacked axially, the joints of the conductors are arranged alternately. This alternating arrangement can be seen in Figure 7A. When a given set of petal-shaped sections is moved clockwise around the central longitudinal axis X, the joints are arranged in the following order: joint 301 from the first folded conductor 400, joint 301' from the second folded conductor 400', joint 301'' from the third folded conductor 400'', joint 301 from the first folded conductor 400, joint 301' from the second folded conductor 400', and joint 301'' from the third folded conductor 400''.
[0084] Figure 12 is an axial view of the cylindrical conductor for the stator. When the stack 500 of folded conductors is formed on the cylindrical conductor for the stator, the junctions of the various folded conductors remain arranged alternately as shown in the figure.
[0085] In each conductor, one of the non-joints may include a half-twist. For example, one or more non-joints may include a half-twist; for instance, all non-joints may include a half-twist, or every other non-joint may include a half-twist.
[0086] Figure 8A shows the joint 302 of the conductor 100 in the first part of the conductor 100, and Figure 8B shows the joint 302 of the conductor 100 in the second part of the conductor 100. Figure 9 shows a half twist provided in the non-jointed portion of the conductor. In the embodiment, the half twist shown in Figure 9 may be provided at the first or second axial end of the cylindrical conductor.
[0087] By providing a half-twist, a first portion 901 of the conductor is provided on the first side of the half-twist, and a second portion 902 of the conductor is provided on the second side of the half-twist.
[0088] The conductor has two surfaces, namely a first surface 1010 and a second surface 1020. The two surfaces define opposing surfaces of the conductor. In the first portion 901 of the conductor, the first surface 1010 of the conductor faces a predetermined direction (for example, towards the diagram in Figure 9), and the second surface 1020 of the conductor faces away from the predetermined direction (for example, away from the diagram in Figure 9). In the second portion 902 of the conductor, the second surface 1020 of the conductor faces a predetermined direction (for example, towards the diagram in Figure 9), and the first surface 1010 of the conductor faces away from the predetermined direction (for example, away from the diagram in Figure 9).
[0089] A predetermined loop may form the first surface, and another loop may form the second surface. Thus, a half-twist changes which loop faces a predetermined direction (which loop is closest). When a cylindrical conductor is formed using a conductor that includes a half-twist, the first surface 1010 faces the central longitudinal axis with respect to the first portion 901 of the conductor, and the second surface 1020 faces the central longitudinal axis with respect to the second portion 902 of the conductor.
[0090] The joint 302 in Figure 8A represents all of the joints 302 in the first portion 901 of the first conductor 100. The joint 302 in Figure 8B represents all of the joints 302 in the second portion 902 of the conductor 100.
[0091] In the first part 901, the joint 302 is arranged as follows: the first layer LAYER1 is positioned closer to the central longitudinal axis X than the second layer LAYER2, the third layer LAYER3, and up to the 15th layer.
[0092] In the second portion 902 of the joint 302, the layers are arranged as follows: the 15th layer (not shown) is the layer closest to the central longitudinal axis, followed by the 14th layer (not shown), and so on. The third layer LAYER3 is positioned closer to the central longitudinal axis X than the second layer LAYER2 and the first layer LAYER1, and the second layer LAYER2 is positioned closer to the central longitudinal axis X than the first layer LAYER1.
[0093] When an electric current is passed through a conductor in use, loops closer to the central longitudinal axis X are heated to a higher temperature than loops further away from the central longitudinal axis X. By incorporating a half-twist, the order in which the conductor loops are arranged relative to the central longitudinal axis is changed, thereby regulating the conductor temperature and avoiding thermal damage.
[0094] The half-twist is preferably placed at the midpoint of the conductor, i.e., at a point in the conductor equidistant from the electrical connection terminals of the conductor. Advantageously, placing the half-twist at the midpoint of the conductor equals the amount of heating in the loop in the first region 901 on the first side of the half-twist and the second region 902 on the second side of the half-twist, and therefore the wear caused by the heating of the conductor is uniformly distributed across the first region 901 and the second region 902. It will be understood that the above description of the half-twist with respect to Figures 8A, 8B, and 9 can be generalized to any number of wires (or layers of wires) forming a conductor.
[0095] It will be understood that the aforementioned half-twist is applied to the first folded conductor 400, the second folded conductor 400', and the third folded conductor 400''.
[0096] A method for manufacturing a stator for a slotless electric motor includes the step of rotating each petal-shaped part around a point on a second circle to align the joints of all petal-shaped parts in parallel, thereby so that the diameter is equal to the second diameter and the joints are positioned equidistant from and around the central longitudinal axis of the cylindrical conductor.
[0097] Figure 11 shows a cylindrical conductor formed from the conductor stack 500 shown in Figures 7A and 7B after the method steps described above have been carried out.
[0098] Figures 10A, 10B, and 10C illustrate a series of steps to rotate the petal-shaped set 510 of the folded conductor shown in Figure 7A to form the stator core shown in Figure 11, and Figure 11 shows a radial perspective view of the cylindrical conductor 1100 formed from the conductor stack 500 shown in Figures 7A and 7B.
[0099] All petal-like parts (i.e., all petal-like parts in a set of petal-like parts) 610, 620 are rotated about a point on the second circle 552, i.e., the point on the second circle 552 closest to a given set of petal-like parts 610, 620. The ends of each petal-like part 410, 420, 410', 420', 410'', 420'' (in the set of petal-like parts 610, 620) closest to the first circle 551 are rotated about the central longitudinal axis X.
[0100] As shown in Figure 10B, all petal-like parts of the petal-like parts sets 610, 620 are rotated in the same direction; that is, each first end of a petal-like part is rotated on a specific side of the plane containing the first circle 551 and the second circle 552 (for example, all first ends are rotated on the "up" side of the plane).
[0101] As shown in Figure 10C, each petal-like part of the petal-like parts sets 610 and 620 is rotated by 90° such that the lengths of each joint 302, 302', and 302'' in each petal-like part are perpendicular to the plane containing the first circle 551 and the second circle 552.
[0102] All of the joints 302, 302', and 302'' of conductor set 500 are positioned on the second circle 552.
[0103] Furthermore, this method may include the step of bending the first axial end of the cylindrical conductor toward the longitudinal axis.
[0104] Figure 11 illustrates a cylindrical conductor 1100 formed from a conductor set 500. The cylindrical conductor 1100 has a first axial end 1110 and a second axial end 1120. A flux ring 1105 is positioned around the cylindrical conductor 1100.
[0105] The conductors 400, 400', and 400'' forming the cylindrical conductor 1100 are connected to the electromotive force source via their respective connectors 120, 120', and 120'' (see Figures 4A, 4B, 5A, 5B, 6A, and 6B). The connectors are connected to the electromotive force source via a star connection.
[0106] The non-joint portion on the first axial end 1110 is bent toward the central longitudinal axis X, thereby reducing the average distance of all points on the non-joint portion from the longitudinal axis X. Advantageously, the reduction in the average distance of all points on the non-joint portion from the first axial side 1110 concentrates the magnetic field (e.g., the magnetic field lines are relatively densely arranged with respect to the central longitudinal axis), and when current flows through the conductor, this can relatively increase the power transfer between the stator and the rotor (acting as a stator) arranged around the cylindrical conductor during use. Advantageously, power loss (I 2 The resistance (R) decreases, which reduces the temperature rise of the conductor when current flows through it. By suppressing the temperature rise of the conductor, a larger torque can be applied to the motor (the motor's rotational speed can be increased).
[0107] The cylindrical conductor 1100 is capable of operating as a three-phase stator for a motor. The first conductor 400 is configured to carry the first phase. The second conductor 400' is configured to carry the second phase (for example, an AC current having a phase lag of 120 degrees with respect to the AC current applied to the first conductor). The third conductor 400'' is configured to carry the third phase (for example, an AC current having a phase lag of 240 degrees with respect to the AC current applied to the first conductor).
[0108] Figure 13 is a flowchart showing a method for manufacturing a stator for a slotless electric motor.
[0109] A method for manufacturing a stator for a slotless electric motor includes the following:
[0110] In S802, an annular cylindrical conductor is arranged. The annular cylinder has an inner radial surface, an outer radial surface, a first axial surface, and a second axial surface. The conductor includes the following bundle of wires. Each wire is arranged parallel to the other wires, and each wire is positioned at a certain distance from the inner radial surface.
[0111] In other words, the conductor containing multiple loops is shown in Figures 2A and 2B and is arranged in an annular shape as described above.
[0112] In S804, multiple joints are joined on a conductor. Each joint includes a region of the conductor where adjacent wires (i.e., adjacent layers of wires) are joined along the joint, the average spacing between adjacent wires is smaller at the joint than at the non-jointed areas, and multiple joints are separated by non-jointed areas.
[0113] In other words, a portion of the conductor is joined, and the conductor described above, as shown in Figures 3A to 3C, is obtained.
[0114] The step of joining multiple joints on a conductor includes applying a bonding compound to a portion of the conductor and activating the bonding compound to form multiple joints.
[0115] As described herein, the bonding compound may be an adhesive such as a resin. For example, the bonding compound may be a resin such as a thermoactivated resin. The required heat may be supplied by at least one of the following: heating by a clamping member, Joule heating of a conductor, or irradiation with infrared radiation.
[0116] The step of joining multiple joints may also include applying a clamping force (e.g., by a clamping member) to the length of the conductor to which the bonding compound (e.g., resin) is applied, thereby reducing the average spacing between wires in the portion of the conductor to which the bonding compound is applied. Once the bonding compound is activated and hardens, the clamping force can be removed.
[0117] Optionally, in S805, a half-twist is added to one of the non-jointed parts of the conductor such that the cross-section of the wire at the first point of the conductor is a mirror image of the cross-section of the wire at the second point of the conductor, so that the wire on the inner radial plane at the first point is on the outer radial plane at the second point.
[0118] The half-twist and its purpose have already been explained in detail.
[0119] In S806, a conductor is bent to provide a plurality of petal-like sections that are repeated along the conductor. Each petal-like section includes a pair of joints connected by non-joints, the pair of joints being arranged parallel to each other, adjacent petal-like sections on the conductor being connected by non-joints, the non-joints in the petal-like sections being bounded by the circumference of a first circle having a first diameter, the non-joints connecting the petal-like sections being bounded by the circumference of a second circle having a second diameter, the second diameter being smaller than the first diameter, and the first and second circles being coplanar and concentric.
[0120] In other words, to provide the conductor shown in Figure 4B and described above, a petal-shaped portion is provided within the conductor.
[0121] Optionally, steps S802 to S806 are repeated to provide multiple folded conductors and to stack the multiple folded conductors in the axial direction.
[0122] In S808, each petal-like part is rotated around a point on the second circle. By aligning the joints of all the petal-like parts in parallel, a stator is provided that includes a cylindrical conductor having a diameter equal to the second diameter, with the joints positioned around the central longitudinal axis of the cylindrical conductor and equidistant from it.
[0123] In other words, each petal-like portion is rotated in the manner shown in the sequence from Figure 10A to Figure 10C to provide a cylindrical conductor as shown in Figure 11.
[0124] In S809, the first axial end of the cylindrical conductor is bent toward the longitudinal axis.
[0125] In S810, a cylindrical conductor is placed within the central hole of a flux ring having an inner diameter larger than the second diameter, thereby providing a stator that includes a cylindrical conductor having a flux ring arranged around the outer radial surface of the conductor.
[0126] For example, the flux ring has an axial length that is less than or equal to the length of the conductor joint. Disadvantageously, in cases where the flux ring is longer than the joint, wires may be lost (for example, the average spacing of wires at the joint may increase).
[0127] In S812, an expandable mandrel is placed at the center of the cylindrical conductor. When the cylindrical conductor is placed within the central hole of the flux ring, the expandable mandrel is expanded, thereby increasing the diameter of the cylindrical conductor to a diameter between the second diameter and the inner diameter of the flux ring.
[0128] Advantageously, the radial distance between the cylindrical conductor and the flux distance is minimized.
[0129] In S814, the second axial end of the cylindrical conductor is bent away from the longitudinal axis.
[0130] The non-joint portion 301 at the second axial end 302 spreads outward, thereby reducing the average axial distance between the non-joint portion and the flux ring.
[0131] Further embodiments are conceivable. It should be understood that any feature described in relation to any one embodiment may be used alone or in combination with other described features, or in combination with any other feature or combination of features of the embodiment. Furthermore, equivalents and modifications not described above may be adopted without departing from the scope of the invention as defined in the appended claims.
[0132] To perform the step of arranging the conductor in an annular cylindrical shape, the annular cylinder has an inner radial surface, an outer radial surface, a first axial surface, and a second axial surface, and the conductor contains a bundle of wires, each wire arranged parallel to the other wires, and each wire is positioned at a constant distance from the inner radial surface. Instead of winding the conductor helically around a longitudinal central axis, the conductor can also be wound as follows: a helix is drawn around a central longitudinal axis, thereby forming the conductor into a cylindrical shape. In such an example, each wire is positioned at a constant distance from the axial surface of the cylindrical shape.
Claims
1. disposing the conductor in an annular cylindrical shape; joining a plurality of junctions of the conductor; and bending the conductor to provide a plurality of petals repeated along the conductor; the junctions include regions of the conductor where adjacent wires are joined along the junctions, and the average spacing between adjacent wires is smaller at the junctions than at non-jointed portions, and a plurality of the junctions are separated by non-jointed portions; Each of the petals includes a pair of joint portions connected by the non-joint portion, and the pair of joint portions are arranged parallel to each other; adjacent petals on the conductor are connected by the non-jointed portions; the unjoined portions of the petals are bounded by the circumference of a first circle, the first circle having a first diameter; the non-junctions connecting the petals are bounded by the circumference of a second circle, the second circle having a second diameter, the second diameter being smaller than the first diameter, and the first and second circles being coplanar and concentric; rotating each of the petals about a point on the second circle and aligning the joints of all of the petals in parallel to provide a stator including a cylindrical conductor having a diameter equal to the second diameter, the joints being disposed around and equidistant from a central longitudinal axis of the cylindrical conductor. A method for manufacturing a stator for a slotless electric motor.
2. 10. The method of claim 1, The step of joining a plurality of the joints onto the conductor includes: applying a bonding compound to portions of the conductor to form a plurality of bonds; method.
3. 3. The method of claim 2, and joining the plurality of joints on the conductor further comprises activating a joining compound. method.
4. 10. The method of claim 1, adding a half twist to one of the unjointed portions of the conductor such that a cross section of the wire at a first point on the conductor is a mirror image of a cross section of the wire at a second point on the conductor; a wire on the inner radial surface at the first point is on the outer radial surface at the second point; method.
5. 10. The method of claim 1, placing the cylindrical conductor within a central bore of a flux ring having an inner diameter greater than the second diameter; providing a stator comprising said cylindrical conductor having a flux ring disposed around an outer radial surface of said conductor; method.
6. 6. The method of claim 5, The flux ring has an axial length that is at least the length of the joint of the conductor, and the flux ring is at least the length of the joint of the conductor. method.
7. 10. The method of claim 1, placing an expandable mandrel in the center of the cylindrical conductor; expanding the expandable mandrel while the cylindrical conductor is disposed within the central bore of the flux ring to increase the diameter of the cylindrical conductor to between the second diameter and an inner diameter of the flux ring; Equipped with method.
8. 10. The method of claim 1, bending a first axial end of the cylindrical conductor toward the central longitudinal axis. method.
9. 10. The method of claim 1, bending a second axial end of the cylindrical conductor away from the central longitudinal axis. method.
10. A method of manufacturing a stator for a slotless electric motor, comprising: disposing the conductors in a semicircular configuration within the confines of an annular cylinder having an inner radial surface, an outer radial surface, a first axial surface, and a second axial surface; bonding a plurality of junctions onto the conductor; adding a half twist to one of the unjointed portions of the conductor such that a cross section of the wire at a first point of the conductor is a mirror image of a cross section of the wire at a second point of the conductor; the junctions comprise areas of conductors in which wires within the area are joined together, with a plurality of the junctions being separated by non-junctions; method.
11. A stator for a slotless electric motor obtainable by the method according to any one of claims 1 to 10.
12. 1. A method of manufacturing a slotless electric motor, comprising: Implementing a method according to any one of claims 1 to 11 to provide a stator; providing a rotor configured to rotate about an axis of the stator; Equipped with method.
13. 1. A stator for a slotless electric motor, comprising: the stator comprises a conductor including a bundle of wires; each wire is arranged parallel to the other wires, the conductor comprising a plurality of junctions, the junctions comprising areas of the conductor where adjacent wires are joined along the junctions, the average spacing between adjacent wires being smaller at the junctions than at non-junctions, and the non-junctions separating a plurality of the junctions; Stator.
14. 14. The stator according to claim 13, the junctions of the conductors are arranged parallel to one another and are arranged on the circumference of a circle; the junctions are disposed about and equidistant from a central longitudinal axis of the cylindrical conductor; Stator.