A wave winding forming process, apparatus, flat wire wave winding, stator and electric machine of a coil

Abstract

The application provides a wave winding forming process, device, flat wire wave winding, stator and motor of a coil, wherein the wave winding forming process comprises the following steps: wave winding forming a conductor to obtain a shaped conductor, the shaped conductor has at least two straight conductor sections extending along the axial direction of the stator and at least one bent bridge conductor section connecting two adjacent straight conductor sections; the bridge conductor section of each shaped conductor is offset relative to the straight conductor section connected thereto along the radial direction of the stator, so that after the shaped conductor is formed into a winding, there is at least a gap t between the adjacent bridge conductor sections of the end of the winding; a plurality of shaped conductors are arranged according to a winding diagram and wound onto a mandrel to form a winding; and the winding is embedded into a stator slot through the mandrel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor stator winding processing, in particular to a wave winding forming process and device of a coil, a wave winding coil of flat wire, a stator and a motor. BACKGROUND

[0002] In new energy vehicles, flat wire motors are increasingly used. In flat wire motors, the forming and insertion of flat wires are divided into hair-pin and wave winding types. Compared with the forming and insertion method of the hair-pin type, the wave winding type is continuously formed, eliminating processes such as twisting and welding, has a shorter end height, occupies less axial space, and improves the power density of the coil, making it suitable for various new energy motors.

[0003] The difficulty of wave winding type forming of flat wires lies in the radial expansion of the wire into the stator slot during insertion. The insulation gap of each layer becomes smaller due to extrusion during expansion, and the end portion of the conductor may be damaged during extrusion, causing a decrease in insulation performance, especially damage to the interphase insulation, resulting in a decrease in the interphase PDIV (Partial Discharge Inception Voltage) value. SUMMARY

[0004] One aspect of the present application aims to solve the technical problem of preventing the insulation gap from decreasing during wave winding type forming of the coil.

[0005] In addition, other aspects of the present application also aim to solve or alleviate other technical problems existing in the prior art.

[0006] The present application provides a wave winding forming process and device of a coil, a wave winding of flat wire, a stator and a motor. Specifically, according to one aspect of the present application, there is provided:

[0007] A wave winding forming process of a coil, comprising the following steps:

[0008] Wave winding forming a conductor to obtain a formed conductor, the formed conductor having at least two straight conductor segments extending in the axial direction of the stator and at least one bent bridge conductor segment connecting adjacent two straight conductor segments;

[0009] Offsetting the bridge conductor segment of each formed conductor relative to the straight conductor segment connected thereto in the radial direction of the stator, so that after forming the formed conductor into a winding, there is at least a gap t between adjacent bridge conductor segments of the end portion of the winding;

[0010] Arranging a plurality of formed conductors according to a winding diagram and winding them onto a mandrel to form a winding;

[0011] The winding is inserted into the stator slot by means of the mandrel.

[0012] Optionally, according to an embodiment of the present application, the bridge conductor section comprises a first bending section and a second bending section connected to each other, the first bending section and the second bending section are connected to a straight conductor section respectively, after the offset, the first bending section and the second bending section respectively protrude outward at least a distance T in the radial direction of the stator relative to the straight conductor section connected thereto.

[0013] Optionally, according to an embodiment of the present application, the distance T is related to the layer number k of the straight conductor section of the profiled conductor in the stator slot.

[0014] Optionally, according to an embodiment of the present application, the gap t is 0.3mm-2.5mm.

[0015] Optionally, according to an embodiment of the present application, in the winding wound by the profiled conductor, the distance T of the straight conductor section of the kth layer counted outward in the radial direction of the stator from the rotor relative to the first bending section or the second bending section connected thereto is (k-1)*t.

[0016] Optionally, according to an embodiment of the present application, the step of inserting the winding into the stator slot by means of the mandrel comprises the following sub-steps:

[0017] Placing the winding in the stator slot by means of the mandrel;

[0018] Expanding the winding in the radial direction of the stator by means of the expansion mechanism installed in the mandrel, so that the winding is inserted into the stator slot.

[0019] Optionally, according to an embodiment of the present application, after the winding is inserted into the stator slot by means of the expansion mechanism, the end of the winding is flared by a flaring tool, so as to increase the gap between the ends of the adjacent profiled conductor layers.

[0020] Optionally, according to an embodiment of the present application, the flaring tool is inserted between the bridge conductor sections opposite in the radial direction of the stator in the axial direction of the stator to flare the end of the winding.

[0021] Optionally, according to an embodiment of the present application, the flaring tool flares gradually inward in the circumferential direction of the stator from the outermost profiled conductor layer in the radial direction of the stator.

[0022] Optionally, according to an embodiment of the present application, the wave winding forming process further comprises the following steps:

[0023] The winding is coated with insulating paint, and the insulating paint is applied to the gap between the profiled conductor layers.

[0024] According to another aspect of the present application, the present application provides a device for wave-forming of coils, wherein comprising

[0025] a wave-forming mechanism for wave-forming a conductor to obtain a shaped conductor, the shaped conductor having at least two straight conductor segments extending along a stator axial direction and at least one bent bridge conductor segment connecting two adjacent straight conductor segments;

[0026] a conductor twisting mechanism for offsetting the bridge conductor segment of each shaped conductor relative to the straight conductor segment connected therewith along a stator radial direction, such that after forming a winding with the shaped conductor, there is at least a gap t between adjacent bridge conductor segments of the end of the winding;

[0027] a winding mechanism for arranging and winding a plurality of shaped conductors according to a winding pattern on a mandrel to form a winding;

[0028] a mandrel for embedding the winding into a stator slot.

[0029] Optionally, according to an embodiment of another aspect of the present application, the bridge conductor segment comprises a first bent segment and a second bent segment connected to each other, the first bent segment and the second bent segment are connected to one straight conductor segment respectively, after the offsetting, the first bent segment and the second bent segment respectively protrude outwardly at least a distance T along the stator radial direction relative to the straight conductor segment connected therewith.

[0030] Optionally, according to an embodiment of another aspect of the present application, the distance T is related to the layer number k of the straight conductor segment of the shaped conductor in the stator slot.

[0031] Optionally, according to an embodiment of another aspect of the present application, the gap t is 0.3mm-2.5mm.

[0032] Optionally, according to an embodiment of another aspect of the present application, in the winding wound by the shaped conductor, the distance T of the straight conductor segment of the kth layer counted outwardly along the stator radial direction from the rotor relative to the first bent segment or the second bent segment connected therewith is (k-1)*t.

[0033] Optionally, according to an embodiment of another aspect of the present application, an expansion mechanism is installed in the mandrel, which expands the winding along the stator radial direction, such that the winding is embedded into the stator slot.

[0034] Optionally, according to an embodiment of another aspect of the present application, the device further comprises

[0035] A flaring tool flares the end of the winding after the winding is expanded by the expansion mechanism, thereby increasing the gap between the ends of the adjacent formed conductor layers;

[0036] A stator drive mechanism drives the stator to move in the axial direction thereof and rotate about the axis thereof to cooperate with the flaring action of the flaring tool.

[0037] Optionally, according to an embodiment of another aspect of the present application, the flaring tool is inserted between the bridge conductor sections opposite in the radial direction of the stator to flare the ends of the winding in the axial direction of the stator.

[0038] Optionally, according to an embodiment of another aspect of the present application, the flaring tool flares from the outermost formed conductor layer in the radial direction of the stator gradually inward in the circumferential direction of the stator.

[0039] According to still another aspect of the present application, the present application provides a pancake wave winding, wherein the pancake wave winding is made according to the wave-forming process described above.

[0040] According to still another aspect of the present application, the present application provides a stator, wherein the stator has the pancake wave winding described above.

[0041] According to still another aspect of the present application, the present application provides an electric machine, wherein the electric machine has the stator described above.

[0042] The advantages of the present application include that the wave-forming process of the present application reserves corresponding forming gaps for the bridge conductor sections according to the layer position of the conductors in the two stator slots when pre-forming the conductors, and flares the ends layer by layer from outside to inside when flaring the coil, so that the ends are not damaged when flared and formed, the inter-phase gap is maintained, and the PDIV and breakdown voltage of the coil after filling the gap with varnish are significantly improved compared to the existing process. BRIEF DESCRIPTION OF DRAWINGS

[0043] The above and other features of the present application will become more apparent by describing in detail the embodiments thereof with reference to the attached drawings in which,

[0044] Figure 1 A flowchart schematically showing a wave-forming process of a coil according to an embodiment of the present application;

[0045] Figure 2 A structure diagram schematically showing a single formed conductor of a pancake wave winding according to an embodiment of the present application;

[0046] Figure 3 An enlarged view of a twisted bridge conductor section of a single formed conductor of a pancake wave winding according to an embodiment of the present application;

[0047] Figure 4 Fig. 6 shows a perspective view of a single shaped conductor of a pancake coil according to an embodiment of the present application after being twisted;

[0048] Figure 5 Fig. 7 shows a schematic view of the structure of an expansion mechanism and a winding before the winding is expanded by the expansion mechanism;

[0049] Figure 6 Fig. 8 shows a schematic view of the structure of an expansion mechanism and a winding after the winding is expanded by the expansion mechanism;

[0050] Figure 7 Fig. 9 shows a schematic view of the structure of a stator with a winding embedded in the slots of the stator;

[0051] Figure 8 Fig. 10 shows an enlarged view of a pancake coil according to an embodiment of the present application when being flared;

[0052] Figure 9 Fig. 11 shows an enlarged view of the end of a flaring tool;

[0053] Figure 10 Fig. 12 shows a schematic view of the positional relationship between a flaring tool and a winding when the winding is being flared;

[0054] Figure 11 Fig. 13 shows a schematic view of a device for wave winding forming of a coil according to an embodiment of the present application. DETAILED DESCRIPTION

[0055] It is easy to understand that, without changing the spirit of the present application, those skilled in the art can propose various structural modes and implementation modes that can be replaced with each other according to the technical solution of the present application. Therefore, the following detailed description and the accompanying drawings are only exemplary descriptions of the technical solution of the present application, and should not be regarded as the whole or as a limitation or restriction on the technical solution of the present application.

[0056] In this specification, the orientation terms such as up, down, left, right, front, back, front surface, back surface, top, bottom, etc. mentioned or possibly mentioned are defined with respect to the structure shown in the drawings, and they are relative concepts, so they can be changed accordingly according to different positions and different use states. Therefore, these or other orientation terms should not be interpreted as restrictive terms. In addition, the terms "first", "second", "third" or the like or similar expressions are only used for description and differentiation purposes, and cannot be understood as indicating or implying the relative importance of the corresponding members.

[0057] The wave winding forming process of the present application aims to improve the insulation performance of the coil, and reference is made to Figure 1Fig. 1 shows a flow chart of a wave winding forming process of a coil according to an embodiment of the present application, which comprises the following steps:

[0058] Step one: wave winding forming of the conductor to obtain a shaped conductor 100, the shaped conductor 100 having at least two straight conductor sections 101 extending in the axial direction of the stator 1000 and at least one bent bridge conductor section 102 connecting two adjacent straight conductor sections.

[0059] The wave winding formed coil is usually composed of a plurality of shaped conductors, for example, four shaped conductors. In the coil forming process, wave winding forming of each conductor is first required, i.e. each conductor is shaped into a shaped conductor 100 having at least two straight conductor sections 101 extending in the axial direction of the stator 1000 and at least one bent bridge conductor section 102 connecting two adjacent straight conductor sections, the shaped conductor 100 of this configuration presents a wave shape with periodicity. Referring to Figure 2 Fig. 2 shows a structural schematic diagram of a single shaped conductor of a flat wire wave winding coil according to an embodiment of the present application. In which two adjacent straight conductor sections 101 are connected by a bridge conductor section 102, the bridge conductor section 102 is bent away from the stator 1000, for example, in the axial direction of the stator, thereby the bridge conductor section 102 forms an isosceles triangle, or half a rhombus structure. At this time, the straight conductor section 101 and the bridge conductor section 102 are in the same plane. The bridge conductor section 102 is configured in a V-like shape, that is, it includes a first bent section 103 and a second bent section 104 connected to each other, the first bent section 103 and the second bent section 104 are connected to one straight conductor section respectively.

[0060] Step two: offset the bridge conductor section 102 of each shaped conductor 100 relative to the straight conductor section 101 connected thereto in the stator radial direction, so that the first and second bent sections 103 and 104 of the bridge conductor section 102 respectively protrude outward at least a distance T in the stator radial direction relative to the straight conductor section connected thereto, so that after the shaped conductor forms a winding, there is at least a gap t between the adjacent bridge conductor sections of the end of the winding. When the two straight conductor sections connected by the bridge conductor section 102 need to be in the same layer in the stator slot, the bridge conductor section 102 as a whole protrudes outward at least a distance T in the stator radial direction relative to the two straight conductor sections during wave winding; and when they need to be in different layers (for example, adjacent layers), the first and second bent sections 103 and 104 respectively protrude outward at least a distance T in the stator radial direction relative to the straight conductor section connected thereto. The relationship between the distance T and the gap t after the shaped conductor 100 forms the winding 200 will be described in detail below.

[0061] Reference Figure 3 , which shows an enlarged view of the twisted bridge conductor section of a single shaped conductor of a flat wire wave winding coil according to an embodiment of the present application. In order to enable a certain insulation gap between the layers of the shaped conductor formed after the shaped conductor 100 is wound into a winding 200 in the stator radial direction, the bridge conductor section 102 of each shaped conductor 100 is offset relative to the straight conductor section 101 connected thereto in the stator radial direction, so that the first and second bent sections 103 and 104 of the bridge conductor section 102 respectively protrude outward a distance T in the stator radial direction relative to the straight conductor section connected thereto, that is, at this time, the first and second bent sections 103 and 104 of the bridge conductor section 102 and the straight conductor section 101 adjacent thereto are not in the same plane, but are offset outward a distance T in the stator radial direction relative to the straight conductor section connected thereto, so that after the shaped conductor forms a winding, there is a gap t between the adjacent bridge conductor sections of the end of the winding. Reference Figure 4 , which shows a perspective view of a single shaped conductor of a flat wire wave winding coil according to an embodiment of the present application after twisting. The presence of the distance T causes there to be a gap t between the layers of the shaped conductor layer of the winding 200 after the winding 200 is wound by the shaped conductor 100, preventing each shaped conductor layer from being attached without a gap, affecting the operation of filling the insulating varnish afterwards, thereby improving the insulation performance of the coil.

[0062] In one embodiment of the application, the distance T is related to the number of layers k in which the straight conductor sections of the profiled conductor are located in the stator slot. The gap t has a value of, for example, 0.3 mm to 2.5 mm, the higher the voltage class of the electric machine, the greater the value of t.

[0063] Step three: The profiled conductors 100 are arranged according to the winding diagram and wound onto the mandrel 40 to form the winding 200.

[0064] The arrangement and winding of the profiled conductors 100 in step three is carried out using a coil W-pin winding process. In the coil W-pin winding process, the winding diagram specifies the number of profiled conductors 100 that can be accommodated in each stator slot 300, thus defining the number of layers of profiled conductors 100 that form the winding 200. The profiled conductors 100 are arranged according to the winding diagram, for example, each profiled conductor 100 is arranged in a stack with a certain distance between the profiled conductors 100, so that the bridge conductor sections 102 at the ends of the adjacent profiled conductor layers are arranged offset from each other. After the arrangement of the profiled conductors 100 is complete, the profiled conductors 100 are wound onto the mandrel 40 in order to pre-form the profiled conductors 100 into the shape of the winding 200, facilitating the introduction of the profiled conductors 100 into the stator slots 300 by radial expansion.

[0065] Step four: The winding 200 is inserted into the stator slots 300 by means of the mandrel 40.

[0066] Reference is made to Figure 5 which shows a schematic view of the structure of the expansion mechanism and the winding before the expansion mechanism expands the winding. After the profiled conductors 100 are wound onto the mandrel 40 to form the winding 200, the winding 200 is inserted into the stator slots 300 by means of the mandrel 40. If the winding 200 is simply introduced into the stator slots 300 in the axial direction of the stator by means of the mandrel 40, it can not be possible to achieve complete insertion of the straight conductor sections 101 of the winding 200 into the stator slots 300. Therefore, in one embodiment of the application, the outer wall 401 of the mandrel 40 is configured to be expandable or contractible in the radial direction of the stator. An expansion mechanism 50 is installed in the mandrel 40, which is capable of expanding the mandrel 40 in the radial direction of the stator 1000, so that the outer wall 401 of the mandrel expands outward and increases in diameter, thus enabling the winding 200 wound on the mandrel 40 to expand in the radial direction of the stator, so that the straight conductor sections 101 of the winding 200 are pushed into the stator slots 300 in the radial direction of the stator. Reference is made to Figure 6Fig. 6 shows a schematic view of the structure of the stator 1000 after the winding 200 is expanded by the expansion mechanism 50. The expansion mechanism 50 is configured to include a center shaft 501 and an inverted conical slider 502 capable of moving on the center shaft 501 in the axial direction of the stator, the slider 502 is initially in a position away from the stator 1000 when the winding 200 is initially placed into the stator 1000, when expansion of the winding 200 is needed, the slider 502 moves in the axial direction of the stator towards the stator 1000, the radius of the contact between the slider 502 and the outer wall 401 of the mandrel 40 gradually increases, so that the outer wall 401 of the mandrel 420 gradually expands outward in the radial direction of the stator, and the straight conductor segments 101 are pushed into the stator slots 300.

[0067] Reference Figure 7 Fig. 6 shows a schematic view of the structure of the stator 1000 after the winding 200 is expanded by the expansion mechanism 50. The expansion mechanism 50 is configured to include a center shaft 501 and an inverted conical slider 502 capable of moving on the center shaft 501 in the axial direction of the stator, the slider 502 is initially in a position away from the stator 1000 when the winding 200 is initially placed into the stator 1000, when expansion of the winding 200 is needed, the slider 502 moves in the axial direction of the stator towards the stator 1000, the radius of the contact between the slider 502 and the outer wall 401 of the mandrel 40 gradually increases, so that the outer wall 401 of the mandrel 420 gradually expands outward in the radial direction of the stator, and the straight conductor segments 101 are pushed into the stator slots 300. Figure 7As can be seen, after the shaped conductor 100 is wound to form the winding 200 and embedded into the stator slot 300, the winding 200 forms a structure with multiple layers of shaped conductor layers, and each shaped conductor layer has multiple shaped conductors. The end of each shaped conductor layer in the stator axial direction is composed of the bridge conductor section 102, and the bridge conductor sections of the ends of adjacent shaped conductor layers are arranged spaced apart from each other. When the straight conductor sections have all been accommodated into the stator slot, assuming that the straight conductor section closest to the rotor is the 1st layer, the conductor thickness of the shaped conductor in the stator radial direction is s, and the insulation gap between the straight conductor sections is r, then the radial offset of the kth layer of straight conductor section relative to the 1st layer of straight conductor section is (k-1)*(s+r). Due to the presence of the distance T and the arrangement of the shaped conductor in the winding, the radial offset of the bridge conductor section of the kth layer relative to the straight conductor section of the kth layer connected thereto, i.e. the distance T, is (k-1)*t; if the two straight conductor sections connected by the bridge conductor section are in the kth layer and the k+1th layer respectively, then the radial offset of the ends of the bridge conductor section relative to the straight conductor sections connected thereto, i.e. the distances T, are (k-1)*t and k*t respectively. It should be noted that the above radial offset is the theoretical radial offset of the shaped conductor after forming the winding, and in the process of winding, the actual radial offset will be reduced due to the mutual extrusion between the copper conductors. In an embodiment of the present application, after the winding 200 is expanded by the mandrel 40 to be embedded into the stator slot 300, the ends of the winding 200 are flared by the flaring tool 60. When the winding is finally combined into the stator, the adjacent bridge conductor sections of the ends of the winding are different in phase and there is an insulation problem, so the adjacent bridge conductor sections of the ends of the winding should be spaced apart with a sufficient gap to prevent breakdown and cause insulation problems. In the process of winding the shaped conductor 100 and expanding the winding 200 by the mandrel 40, the distance T formed during the pre-shaping of the shaped conductor 100 can be reduced due to the extrusion between the multiple layers of shaped conductors, which reduces the gap between the multiple layers of shaped conductors of the winding 200 and can affect the subsequent insulation performance. Therefore, the bridge conductor sections 102 of the ends of the winding 200 can be flared by the flaring tool 60 to increase the gap t between the bridge conductor sections 102 of the ends of each layer of shaped conductor layer. This can reserve more space for coating with insulating paint and improve the insulation performance of the ends of the winding. After the flaring is completed, the insulation gap between the bridge conductor sections 102 of the ends of the winding can be at least 0.1 mm.

[0068] Reference Figure 8This diagram illustrates a flat-wire wave-wound coil according to an embodiment of the present invention during flaring. In the shaped winding 200, each shaped conductor layer and its adjacent shaped conductor layers are arranged with a bridging conductor section 102 approximately offset from each other. Here, taking the outermost shaped conductor layer 1 along the stator radial direction as the first layer, the bridging conductor section directly opposite the end of the outermost shaped conductor layer 1 along the stator radial direction is the end of the bridging conductor section of the third shaped conductor layer 3 from the outside in, because the end of the bridging conductor section of the second shaped conductor layer 2 is offset from the bridging conductor section of the first shaped conductor layer 1 along the stator radial direction. Thus, a rhomboid space 11 is formed between the bridging conductor section at the end of the first shaped conductor layer 1 and the bridging conductor section directly opposite it along the stator radial direction. Figure 8 The space is already filled by the flaring fixture 60. The flaring fixture 60 is inserted into this rhomboid space 11 at the end facing the stator 1000 to expand it, thereby increasing the gap between the bridging conductor segments at the ends of adjacent molded conductor layers (e.g., the first and second layers). Reference Figure 9 The diagram shows an enlarged view of the end of the flaring tool. The end of the flaring tool 60 facing the stator 1000 is configured, for example, as an isosceles triangle (i.e., a half rhombus) that matches the rhomboid space 11, so as to better insert into the rhomboid space 11 for expansion.

[0069] In one embodiment of the invention, the flaring fixture 60 flares the stator gradually inward from the outermost molded conductor layer along the stator periphery in the radial direction of the stator. (See reference) Figure 10 This diagram illustrates the positional relationship between the flaring fixture and the winding during the flaring process. Figure 10 As can be seen, the flaring fixture 60 is arranged on an axis extending radially along the stator and can move along this axis. The flaring fixture 60 first flares the bridging conductor sections at the ends of the first and second layers, that is, it is first inserted axially into the diamond-shaped space between the bridging conductor sections at the ends of the first and third layers, which are opposite to them in the radial direction of the stator. Then, it flares the bridging conductor sections at the ends of the second and third layers, that is, it is inserted axially into the diamond-shaped space between the bridging conductor sections at the ends of the second and fourth layers, which are opposite to them in the radial direction of the stator. This flaring method, proceeding from the outside in, allows the flaring fixture 60 to withstand a smaller expansion force during flaring and also facilitates easier entry of the flaring fixture 60 into the diamond-shaped spaces between the formed conductor layers. When flaring the bridging conductor section in the same layer along the periphery of the stator, the flaring fixture 60 only moves up and down, while the stator 1000 rotates along its central axis via the stator drive mechanism 70, thereby shifting different bridging conductor sections.

[0070] In one embodiment of the present application, after the expansion of the winding 200, insulating varnish is coated on the winding 200. The coating of the insulating varnish is generally performed by immersing the winding 200 in the insulating varnish. Due to the gaps between the shaped conductor layers, especially the gaps between the bridge conductor sections of the end portions of the shaped conductor layers, the insulating varnish can enter the gaps to coat the winding 200 well, so that the insulating varnish can uniformly and comprehensively cover the surface of the winding 200, ensuring the insulation performance of the winding 200.

[0071] According to another aspect of the present application, a device for wave-forming of a coil is also provided, which can be used to perform the wave-forming process described above. Referring to Figure 11 which shows the device for wave-forming of a coil according to one embodiment of the present application, since the specific shape and internal structure of each component are not the subject of the present application, for the sake of clarity and simplicity, all these components are schematically given in the form of structural modules, and the person skilled in the art can select appropriate module shapes and structural forms, etc. under the inspiration of the structural diagram. In addition, the structural diagram given is one embodiment of the present application, and the person skilled in the art can make various modifications without departing from the spirit of the present application after referring to the diagram, and these modifications should also be within the protection scope of the present application. The device comprises

[0072] a wave-forming mechanism 10 for wave-forming a conductor to obtain a shaped conductor 100 having at least two straight conductor sections 101 extending in the axial direction of the stator and at least one bridge conductor section 102 connecting two adjacent straight conductor sections;

[0073] a conductor twisting mechanism 20 for offsetting the bridge conductor section 102 of each shaped conductor 100 relative to the straight conductor section 101 connected thereto in the radial direction of the stator, so that after forming the winding from the shaped conductors, there is at least a gap t between the adjacent bridge conductor sections of the end portions of the winding;

[0074] a winding winding mechanism 30 for arranging and winding a plurality of shaped conductors 100 according to a winding pattern on a mandrel 40 to form a winding 200;

[0075] a mandrel 40 for embedding the winding 200 into a stator slot 300;

[0076] In one embodiment of the present application, the bridge conductor section 102 comprises a first bending section 103 and a second bending section 104 connected to each other, and each of the first bending section 103 and the second bending section 104 is connected to a straight conductor section, and after the offset, each of the first bending section 103 and the second bending section 104 protrudes outward at least a distance T relative to the straight conductor section connected thereto in the stator radial direction.

[0077] In one embodiment of the present application, the distance T is associated with the layer number k of the straight conductor section of the profiled conductor in the stator slot.

[0078] In one embodiment of the present application, the gap t is 0.3mm-2.5mm.

[0079] In one embodiment of the present application, in the winding wound by the profiled conductor, the distance T of the straight conductor section of the kth layer counted outward in the stator radial direction from the rotor relative to the first bending section or the second bending section connected thereto is (k-1)*t.

[0080] In one embodiment of the present application, an expansion mechanism 50 is installed in the mandrel 40, which expands the winding 200 in the stator radial direction so that the winding 200 is embedded into the stator slot 300. In this embodiment, the mandrel 40 comprises a mandrel outer wall 401, the expansion mechanism 50 comprises a center shaft 501 and a slider 502, and the outer wall 401 of the mandrel 40 can be expanded and contracted in the radial direction of the mandrel 40. The slider 502 is configured as an inverted cone and is installed on the center shaft 501 and can slide up and down along the center shaft 501. When the slider 502 slides along the center shaft 501 towards the stator 1000, the diameter of the slider continuously increases, pushing the outer wall 401 of the mandrel 40 to expand outward, thereby driving the winding 200 wound on the outer wall 401 of the mandrel 40 to expand outward and embed into the stator slot 300.

[0081] In one embodiment of the present application, the device further comprises

[0082] a flaring tool 60 which flares the end of the winding 200 after the winding 200 is expanded by the expansion mechanism 50, thereby increasing the gap between the end of the adjacent profiled conductor layers;

[0083] a stator driving mechanism 70 which drives the stator 1000 to move in the axial direction thereof and rotate about the axis thereof to cooperate with the flaring action of the flaring tool 60.

[0084] In one embodiment of the present application, the flaring tool 60 is inserted between the bridge conductor sections opposite in the stator radial direction to flare the end of the winding 200 in the stator axial direction.

[0085] In one embodiment of the present application, the flaring tool 60 gradually flares the outermost formed conductor layer in the stator radial direction, in the stator circumferential direction.

[0086] Since the wave winding forming process for the coil of the present application has been described in great detail in the foregoing, more possible devices or mechanisms that can be added, modified or replaced in the device for wave winding forming of the coil according to the present application can be directly implemented by referring to the specific description of the corresponding part in the foregoing, which will not be described here again.

[0087] According to another aspect of the present application, a flat wire wave winding coil is also proposed, wherein the flat wire wave winding coil is made according to the above process.

[0088] According to another aspect of the present application, a stator is also proposed, which has the above-mentioned flat wire wave winding coil.

[0089] According to another aspect of the present application, an electric machine is also proposed, which has the above-mentioned stator.

[0090] It should be understood that all the above preferred embodiments are exemplary rather than limiting, and various modifications or variations of the specific embodiments described above made by those skilled in the art under the concept of the present application shall be within the legal protection scope of the present application.

Claims

1. A coil winding forming process, characterized in that, Includes the following steps: The conductor is wave-shaped to obtain a shaped conductor, the shaped conductor having at least two straight conductor segments extending along the stator axial direction and at least one bent bridging conductor segment connecting two adjacent straight conductor segments; The bridging conductor section of each shaped conductor is offset relative to the straight conductor section connected to it in the stator radial direction, such that after the shaped conductor is formed into a winding, there is at least a gap t between adjacent bridging conductor sections at the ends of the winding. Multiple shaped conductors are arranged according to the winding diagram and wound onto the mandrel to form a winding; The windings are embedded into the stator slots via a mandrel; The bridging conductor section includes a first bent section and a second bent section connected to each other. The first bent section and the second bent section are respectively connected to a straight conductor section. After offsetting, the first bent section and the second bent section protrude outward by at least a distance T in the stator radial direction relative to the straight conductor section they are connected to.

2. The wave winding forming process according to claim 1, characterized in that, The distance T is related to the number of layers k in which the straight conductor section of the shaped conductor is located in the stator slot.

3. The wave winding forming process according to claim 1, characterized in that, The gap t is 0.3mm-2.5mm.

4. The wave winding forming process according to claim 2, characterized in that, In the winding formed by the shaped conductor, the distance T of the straight conductor segment of the kth layer from the rotor outward along the radial direction of the stator relative to the first or second bent segment connected to it is (k-1)*t.

5. The wave winding forming process according to claim 1, characterized in that, The step of embedding the winding into the stator slot using a mandrel includes the following sub-steps: The windings are placed in the stator slots using a mandrel; The winding is expanded radially in the stator by an expansion mechanism installed in the mandrel, so that the winding is embedded in the stator slot.

6. The corrugated forming process according to claim 5, characterized in that, After the winding is expanded by the expansion mechanism to embed it into the stator slot, the ends of the winding are widened by the widening tool, thereby increasing the gap between the ends of adjacent molded conductor layers.

7. The wave winding forming process according to claim 6, characterized in that, The ends of the winding are flared by inserting a flaring tool along the stator axial direction between opposing bridging conductor sections along the stator radial direction.

8. The corrugated forming process according to claim 7, characterized in that, The flaring tooling gradually flares inward from the outermost formed conductor layer along the stator periphery, starting from the radial direction of the stator.

9. The wave winding forming process according to claim 1, characterized in that, It also includes the following steps: The winding is coated with an insulating varnish, which is applied to the gaps between the shaped conductor layers.

10. An apparatus for wave winding of a coil, characterized in that, include A wave-forming mechanism for wave-forming a conductor to obtain a shaped conductor having at least two straight conductor segments extending along the stator axial direction and at least one bent bridging conductor segment connecting two adjacent straight conductor segments. A conductor torsion mechanism that offsets the bridging conductor section of each shaped conductor relative to the straight conductor section connected thereto in the stator radial direction, such that after the shaped conductor is formed into a winding, there is at least a gap t between adjacent bridging conductor sections at the ends of the winding. A winding mechanism that arranges multiple shaped conductors according to a winding diagram and winds them onto a mandrel to form a winding; The spindle, which embeds the windings into the stator slots; The bridging conductor section includes a first bent section and a second bent section connected to each other. The first bent section and the second bent section are respectively connected to a straight conductor section. After offsetting, the first bent section and the second bent section protrude outward by at least a distance T relative to the straight conductor section connected to them in the stator radial direction. The distance T is related to the number of layers k in the stator slot of the straight conductor section of the shaped conductor; An expansion mechanism is installed in the mandrel, which expands the winding in the stator radial direction so that the winding is embedded in the stator slot.

11. The apparatus according to claim 10, characterized in that, The gap t is 0.3mm-2.5mm.

12. The apparatus according to claim 11, characterized in that, In the winding formed by the shaped conductor, the distance T of the straight conductor segment of the kth layer from the rotor outward along the radial direction of the stator relative to the first or second bent segment connected to it is (k-1)*t.

13. The apparatus according to claim 10, characterized in that, The device also includes The flaring fixture flares the ends of the winding after it has been expanded by the expansion mechanism, thereby increasing the gap between the ends of adjacent molded conductor layers; A stator drive mechanism that drives the stator to move along its axial direction and rotate about its axis to cooperate with the flaring action of the flaring tool.

14. The apparatus according to claim 13, characterized in that, The flaring tool is inserted along the stator axial direction between opposite bridging conductor sections along the stator radial direction to flare the ends of the winding.

15. The apparatus according to claim 14, characterized in that, The flaring tooling gradually flares inward from the outermost formed conductor layer along the stator periphery, starting from the radial direction of the stator.

16. A flat wire wave wound coil, characterized in that, The flat wire corrugated coil is manufactured using the corrugating process according to any one of claims 1 to 9.

17. A stator, characterized in that, The stator has a flat wire wave-wound coil as described in claim 16.

18. An electric motor, characterized in that, The motor has a stator as described in claim 17.

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