Winding and shaping method for high-voltage hollow stator coil of superconducting linear motor

Abstract

The application relates to the technical field of high-speed magnetic suspension transportation, and discloses a superconducting linear motor high-voltage hollow stator coil winding and shaping method. The method comprises the following steps: coating thermosetting paint on the insulating paint film of a wire; transposing and twisting the wire, and integrally binding the outermost wire after transposing and twisting by using an insulating tape to obtain a Litz wire; winding and shaping a hollow coil on an inner framework of a winding tool by using the Litz wire; transferring the hollow coil from the inner framework of the winding tool to an inner framework of a shaping tool; matching and fixing the outgoing wire joint of the hollow coil with the outgoing wire joint positioning part of the shaping tool; arranging a pressing plate on the shaping tool and applying a pre-pressure to the pressing plate, so that the pressing plate is completely attached to the shaping tool; and performing a drying operation on the shaping tool, so that the hollow coil on the inner framework of the shaping tool is shaped, dried and solidified.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high-speed magnetic levitation transportation, and particularly relates to a winding and shaping method for a high-voltage hollow stator coil of a superconducting linear motor. BACKGROUND

[0002] A superconducting linear motor composed of a superconducting mover and a ground coil stator has the advantages of high power density, high efficiency and small loss, and has broad application prospects in high-speed magnetic levitation rail transportation and space electromagnetic launching. In order to avoid magnetic saturation and reduce the mutual attraction between the superconducting magnet and the stator coil, the stator of the superconducting linear motor is generally designed as a hollow coil structure without an iron core, and is cast and solidified into a stator module by epoxy resin.

[0003] The long-stator superconducting linear motor has high requirements for the size precision and consistency of the stator coil, and excessive size error will cause distortion of the traveling wave magnetic field generated by the stator, increase the thrust fluctuation, cause vehicle-rail coupled vibration, and have an adverse effect on the propulsion performance.

[0004] The power supply current frequency of the long-stator high-speed superconducting linear motor is high, and in order to reduce the eddy current loss and heat generation of the stator coil, a Litz wire formed by twisting a plurality of mutually insulated wires is generally used for winding. Compared with a single-wire conductor with the same cross section, the Litz wire has the problems of being difficult to shape, being easy to shrink and rebound, being twisted to change the shape of the coil, and the like, which affect the shape consistency and size precision of the wound coil.

[0005] After the winding of the iron-core-free high-voltage stator coil is completed, a process such as vacuum impregnation, mica wrapping or direct resin insulation layer casting and solidification is required, and the consistency and stability of the shape of the coil during the process implementation are required to be high. In order to ensure that the wound Litz coil is stable in shape, consistent and accurate in size during the subsequent process, the method of winding the Litz coil on a ring-shaped insulation framework, binding and fixing the coil and the framework using a binding belt, and integrally casting the coil with the support and binding parts with resin is generally used; or the method of directly brushing insulating paint on the outer surface of the coil on the winding framework during or after winding, and then shaping after drying.

[0006] However, the method of pouring resin or wrapping in mica tape together with the coil, support framework, and help strap, etc. can guarantee the size of the coil, but there are more foreign matters such as insulation framework, help strap, etc. in the stator module, and the thermal expansion coefficient and insulation performance of the foreign matters are quite different from those of the poured resin, impregnated varnish, and mica tape, etc. During the operation of the module, insulation defects and cracks are easily formed at the joint surfaces of different parts such as the framework, and partial discharge and insulation damage are induced. In the process of coating and then drying and curing the insulation paint during winding, more raised stains are formed on the surface of the coil in the non-vacuum coating process, which destroys the flatness of the surface of the coil, and the non-vacuum environment coating easily forms more air bubbles in the paint layer and leaves closed gaps between the turns of the coil. The above insulation defects are extremely easy to induce partial discharge and insulation damage during the high-voltage operation of the coil. SUMMARY

[0007] The application provides a superconducting linear motor high-voltage hollow stator coil winding and shaping method, which can solve the technical problems in the prior art.

[0008] The application provides a superconducting linear motor high-voltage hollow stator coil winding and shaping method, which comprises the following steps:

[0009] A thermosetting coating is coated outside the insulation paint film of the wire;

[0010] The wire is transposed and stranded, and the outermost part of the transposed and stranded wire is integrally bound by an insulation tape to obtain a Litz wire;

[0011] The Litz wire is wound and shaped into a hollow coil on an inner framework of a winding tool;

[0012] The hollow coil is transferred from the inner framework of the winding tool to an inner framework of a shaping tool;

[0013] The lead joint of the hollow coil is matched and fixed with a lead joint positioning part of the shaping tool;

[0014] A pressing plate is arranged on the shaping tool, and a pre-pressure is applied to the pressing plate, so that the pressing plate is completely attached to the shaping tool;

[0015] The shaping tool is subjected to a drying operation to shape, dry, and cure the hollow coil on the inner framework of the shaping tool.

[0016] Preferably, winding and shaping the hollow coil on the inner framework of the winding tool comprises:

[0017] The Litz wire is wound and shaped into a hollow coil on the inner framework of the winding tool in the form of back-to-back centering against the tool plate of the winding tool.

[0018] Preferably, the transferring of the air-core coil from the inner skeleton of the winding tool to the inner skeleton of the setting tool comprises:

[0019] The winding tool and the setting tool are matched through the pin hole, and the inner skeleton of the winding tool is matched with the inner skeleton of the setting tool;

[0020] The air-core coil is pushed into the coil groove of the setting tool by the coil top rod passing through the tool plate, and the air-core coil is transferred to the inner skeleton of the setting tool.

[0021] Preferably, the pre-pressing force is applied to the pressing plate by the clamping device.

[0022] Preferably, the clamping device comprises a pre-tightening bolt and a tool clamp.

[0023] Preferably, the thermosetting coating comprises an epoxy resin coating, a polyester coating and a thermosetting acrylic coating.

[0024] Preferably, the insulation tape comprises a glass silk tape, a Nomex paper and an imine film.

[0025] Preferably, the shape of the air-core coil is single-pie or double-pie.

[0026] Through the above technical solution, the coil can be automatically set after winding without the help of the skeleton and the binding tape, and after setting, the coil itself has a certain rigidity and will not change in size under the influence of general external force, so that during the subsequent processes of vacuum impregnation and vacuum resin pouring, the fluid insulation material such as insulation paint and insulation resin can fully integrate with all external surfaces of the coil, eliminating the influence of coil turn-to-turn air bubbles and binding structure on the coil insulation. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings included are part of the specification and illustrate embodiments of the present application and, together with the written description, serve to explain the principles behind the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0028] Figure 1 A flow chart of a superconducting linear motor high-voltage air-core stator coil winding and setting method according to an embodiment of the present application is shown;

[0029] Figure 2 A schematic diagram of the transfer of the air-core coil from the winding tool to the setting tool according to an embodiment of the present application is shown;

[0030] Figure 3 A schematic diagram of the assembly and setting of the air-core coil and the setting mold according to an embodiment of the present application is shown.

[0031] Figure 4 An application example of a hollow coil is shown.

[0032] Legend of the drawing

[0033] 1 shaping tool; 11 inner skeleton of the shaping tool; 12 matching positioning pin;

[0034] 13 coil slot; 2 hollow coil; 3 winding tool;

[0035] 31 inner skeleton of the winding tool; 32 coil top rod; 14 matching bolt hole;

[0036] 15 lead wire joint positioning part; 21 lead wire joint of the hollow coil; 4 pressing plate;

[0037] 5 pre-tightening bolt; 6 insulation support cushion block, 7 pouring resin. DETAILED DESCRIPTION

[0038] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0039] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0040] The relative arrangement of parts and steps, numerical expressions, and values set forth in the examples herein are not intended to limit the scope of the application unless otherwise specifically stated. It is to be understood that the actual dimensions of the various parts shown in the drawings are not necessarily to scale, and that the dimensions can be arbitrarily set forth for the clarity of presentation and because it is the intent of the inventor to provide the best description of the application relative to the known art. Techniques, methods, and apparatus known to those of ordinary skill in the art can not be discussed in detail, but can be assumed by those of ordinary skill in the art. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation on the scope of the application. Thus, other examples of the exemplary embodiments can have different values. It is to be noted that like numbers and letters refer to like elements throughout the several views of the drawings, and that the drawings are not necessarily to scale as the emphasis is generally upon the functional aspects of the application.

[0041] Figure 1 A flow chart of a superconducting linear motor high-voltage hollow stator coil winding and shaping method according to an embodiment of the application is shown.

[0042] As shown in Figure 1 An embodiment of the application provides a superconducting linear motor high-voltage hollow stator coil winding and shaping method, wherein the method comprises:

[0043] S100, coating a thermosetting coating on the insulating paint film of the wire;

[0044] That is, the outer surface of each single wire is coated with not only the insulating paint film but also the thermosetting coating.

[0045] S102, transposition stranding the wire and integrally binding the outermost wire after transposition stranding with an insulating tape to obtain a Litz wire;

[0046] S104, winding and shaping a hollow coil on the inner framework of the winding tool using the Litz wire;

[0047] S106, transferring the hollow coil from the inner framework of the winding tool to the inner framework of the shaping tool;

[0048] S108, cooperating and fixing the outgoing wire joint of the hollow coil with the outgoing wire joint positioning part of the shaping tool;

[0049] Thus, the shaping of the outgoing wire of the hollow coil is completed. For example, the shaping tool is provided with a corresponding positioning part according to the designed position of the outgoing wire of the hollow coil, so as to ensure that the shapes of the two outgoing wires of the shaped hollow coil are the same as the design and fixed.

[0050] S110, setting a pressing plate on the shaping tool and applying a pre-pressing force to the pressing plate, so that the pressing plate is completely attached to the shaping tool;

[0051] S112, performing a drying operation on the shaping tool to dry and cure the air core coil on the inner framework of the shaping tool.

[0052] For example, the shaping tool including the air core coil can be transferred as a whole into a drying furnace, and a drying temperature is applied according to the curing requirement of the thermosetting paint coated on the Litz wire. After the air core coil is dried and cured, the pressing plate can be opened and the air core coil can be taken out, and thus the air core stator coil and the lead wire joint thereof with accurate size, stability and without any supporting and binding structure are obtained.

[0053] Through the technical solution, the coil can be automatically shaped after being wound without the help of the framework and the binding belt, and the shaped coil has a certain rigidity and will not change in size under the influence of general external force, so that the fluid insulation material such as insulating paint and insulating resin can fully combine with all the outer surfaces of the coil in the subsequent processes of vacuum paint immersion and vacuum resin pouring, and the influence of the coil turn-to-turn air gap and the binding structure on the coil insulation is eliminated.

[0054] According to an embodiment of the present application, the winding of the Litz wire into the air core coil on the inner framework of the winding tool includes:

[0055] The winding of the Litz wire into the air core coil on the inner framework of the winding tool is in the form of inner centering against the tool plate of the winding tool.

[0056] The inner framework of the winding tool is arranged on the tool plate of the winding tool.

[0057] According to an embodiment of the present application, the transferring of the air core coil from the inner framework of the winding tool to the inner framework of the shaping tool includes:

[0058] The winding tool and the shaping tool are matched through pin hole cooperation, so that the inner framework of the winding tool is attached to the inner framework of the shaping tool.

[0059] For example, the inner framework of the shaping tool is provided with a matching positioning hole corresponding to a positioning hole on the inner framework of the winding tool, and the positioning hole and the matching positioning hole are matched through a positioning pin 12 (as shown in Figure 2 ).

[0060] The air core coil is pushed as a whole into the coil groove of the shaping tool by a coil ejector rod penetrating through the tool plate, so that the air core coil is transferred to the inner framework of the shaping tool.

[0061] That is, the coil ejector rod can penetrate through the tool plate and be placed on the air core coil, and by applying an external force to the coil ejector rod, the air core coil can be transferred to the inner framework of the shaping tool.

[0062] Specifically, as shown in Figure 2As shown, the positioning pin 12 is inserted into the positioning hole of the shaping fixture 1 and mates with the positioning hole opened on the inner skeleton 31 of the winding fixture 3. After the winding fixture 3 with the finished hollow coil 2 is pressed together with the shaping fixture 1 through the pin hole, the hollow coil 2 corresponds to the coil groove 13. Then, the coil push rod 32 can be used to push the hollow coil 2 into the coil groove 13 from the outside of the winding fixture 3 to realize the transfer of the hollow coil 2.

[0063] The coil slot can be a ring-shaped structure with the same shape as the hollow coil, such as a ring-shaped coil slot. The inner dimension of the ring-shaped coil slot (i.e., the outer dimension of the inner skeleton of the shaping fixture) is the same as the inner skeleton dimension of the coil being wound, while the outer dimension is slightly larger than the designed outer dimension of the coil being wound, and the depth is consistent with the designed thickness of the coil. In other words, the outer dimension and depth of the coil slot can be determined according to the coil design dimensions.

[0064] According to one embodiment of the present invention, a clamping device is used to apply pre-pressure to the pressure plate.

[0065] According to one embodiment of the present invention, the clamping device includes a preload bolt and a tooling clamp.

[0066] Those skilled in the art should understand that the above description of the clamping device is merely exemplary and not intended to limit the present invention. Any other clamping device or tooling fixture that can apply preload can be applied to the present invention.

[0067] Specifically, taking the clamping device as a pre-tightening bolt as an example, such as Figure 3 As shown, the hollow coil is placed in the coil slot 13. After the lead wire of the hollow coil 2 is connected to the connector, the lead wire connector 21 of the hollow coil is connected to the lead wire connector positioning part 15 at the bottom of the shaping fixture 1, which is set according to the final installation position. The pressure plate 4 has bolt mounting holes corresponding to the mating bolt holes 14 of the shaping fixture. After the pressure plate 4 is placed on the shaping fixture 1, the pressure plate 4 can apply pre-pressure to the hollow coil 2, which is higher than the design part, in the thickness direction by tightening all the pre-tightening bolts 5 (that is, tightening by engaging with the mating bolt holes 14 and the bolt mounting holes). Since the outer edge of the coil slot 13 can be slightly larger than the outer contour of the hollow coil 2, the internal stress generated by the compression in the thickness can be released in the outer dimension, avoiding the problem of excessive internal stress in the coil causing the wire inside the Litz wire to break and be damaged.

[0068] According to one embodiment of the present invention, the thermosetting coating includes epoxy resin coating, polyester coating and thermosetting acrylic coating.

[0069] The thermosetting coating has the characteristics of being a viscous liquid or gel when applied at room temperature, and becoming an insoluble and infusible solid after heating and drying, and also has insulating properties.

[0070] Those skilled in the art should understand that the above-mentioned coating is only exemplary and is not intended to limit the present application.

[0071] According to an embodiment of the present application, the insulating tape comprises glass fiber tape, Nomex paper and imine film.

[0072] Those skilled in the art should understand that the above-mentioned insulating tape is only exemplary and is not intended to limit the present application.

[0073] According to an embodiment of the present application, the shape of the hollow coil is single-pie or double-pie.

[0074] In addition to the above-mentioned single-pie coil and double-pie coil, other forms of coils are also applicable to the present application.

[0075] In addition, as Figure 3 shown, the shaped hollow coil obtained by the above-mentioned method has all the outer surfaces of the hollow coil fully bonded with the poured resin without the support of the insulating framework and other shaped components, thereby eliminating the influence of the framework, the binding tape and the like on the insulation consistency of the hollow coil.

[0076] Furthermore, by measuring the thickness dimension consistency of the shaped hollow coil, it is found that the coil winding and shaping method of the present application can control the thickness dimension deviation of the coil within 1%.

[0077] As can be seen from the above-mentioned embodiments, the method of the present application has at least the following advantages compared with the prior art:

[0078] 1) The hollow stator coil shaped by the method of the present application does not require any inner framework and turn-to-turn binding tape structure, and can ensure the size precision, consistency and stability of the coil, greatly simplifying the structure of the stator coil, eliminating the cost of the insulating coil framework, and eliminating the influence of the inconsistent tension of the multiple binding tapes on the size of the coil;

[0079] 2) The hollow stator coil without framework and binding tape can make the insulating paint and resin glue more fully bonded with all the surfaces of the stator coil during the subsequent vacuum paint immersion or resin pouring process, and there is no other insulating medium such as framework and binding tape in the middle, thereby improving the consistency of the insulating layer and improving the insulation performance and reliability of the module

[0080] 3) The winding and shaping method has the same shaping effect on the coil lead, and can ensure the consistency of the size and position of the lead, and during the assembly of the coil module, no other auxiliary tool is required to ensure the precise docking of the lead with the connector socket in the module.

[0081] In the description of the application, it should be understood that the orientation words such as "front, back, upper, lower, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship are generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0082] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0083] In addition, it should be noted that the use of "first", "second" and the like to define parts only facilitates the differentiation of corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as a limitation on the scope of protection of the application.

[0084] The above only describes the preferred embodiments of the application and is not intended to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the scope of protection of the application.

Claims

1. A method for winding and shaping high-voltage hollow stator coils of a superconducting linear motor, characterized in that, The method includes: A thermosetting coating is applied to the outside of the insulating varnish film of the conductor; The conductors are transposed and twisted, and then the outermost part of the transposed and twisted conductors is bound together with insulating tape to obtain Litz wire. Hollow coils are formed by winding the Litz wire on the inner skeleton of the winding tooling. The hollow coil is transferred from the inner frame of the winding fixture to the inner frame of the shaping fixture. The lead wire connector of the hollow coil is fitted and fixed with the lead wire connector positioning part of the shaping tool; A pressure plate is set on the shaping fixture and a pre-pressure is applied to the pressure plate so that the pressure plate is completely fitted to the shaping fixture; The shaping tooling is dried to ensure that the hollow coils on the inner frame of the shaping tooling are shaped, dried and cured. Winding a hollow coil onto the inner frame of a winding fixture using the aforementioned Litz wire includes: A hollow coil is formed by winding the Litz wire on the inner skeleton of the winding fixture, back against the fixture plate of the winding fixture, in an internal centering manner. Transferring the hollow coil from the inner frame of the winding fixture to the inner frame of the shaping fixture includes: The winding fixture and the shaping fixture are fitted together through pin holes so that the inner skeleton of the winding fixture fits into the inner skeleton of the shaping fixture. The hollow coil is pushed into the coil slot of the shaping fixture by the coil push rod passing through the tooling plate, so that the hollow coil is transferred to the inner frame of the shaping fixture.

2. The method according to claim 1, characterized in that, A clamping device is used to apply pre-pressure to the pressure plate.

3. The method according to claim 2, characterized in that, The clamping device includes a pre-tightening bolt and a tooling clamp.

4. The method according to any one of claims 1-3, characterized in that, The thermosetting coatings include epoxy resin coatings, polyester coatings, and thermosetting acrylic coatings.

5. The method according to any one of claims 1-3, characterized in that, The insulating tape includes glass ribbon, Nomex paper, and imide film.

6. The method according to any one of claims 1-3, characterized in that, The hollow coil is in the shape of a single disc or a double disc.

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