Bobbin for motor

Abstract

To provide a bobbin for a motor that can be expected to ensure cooling performance and have structural stability.SOLUTION: A bobbin for a motor according to an embodiment of the present invention includes a bobbin body around which a superconducting coil is wound, and a reinforcing body made of reinforced plastic containing reinforcing fibers and surrounding a side surface of the bobbin body.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motor bobbin, and more particularly to a motor bobbin that can be expected to ensure cooling performance and structural stability. [Background technology]

[0002] The development of drive motors is required to improve the performance and fuel efficiency of electric vehicles (EV) and hybrid electric vehicles (HEV), which use electricity as their primary power source.

[0003] Meanwhile, in 1911, Heike Kamerlingh-Onnes of Leiden University in the Netherlands conducted an experiment to measure the electrical resistance of mercury and discovered that the electrical resistance suddenly disappeared at an absolute temperature of 4.2K (-268.8°C). This led to the use of low-temperature superconductors such as NbTi and SnTi in applications requiring high magnetic fields.

[0004] High-temperature superconductors were discovered by Johannes Bednorz and Karl Muller of Switzerland in 1987. Since then, research has been actively conducted to improve the critical temperature and critical current density of high-temperature superconductors.

[0005] As a result, research has recently been conducted into technology for applying superconductors to drive motors in order to improve their performance, and as part of this research, an interior permanent magnet synchronous motor has been proposed.

[0006] The contents described above as the background art are merely intended to provide an understanding of the background to the present invention, and should not be construed as an admission that they constitute prior art already known to those of ordinary skill in the art. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-2000-0007386 (February 7, 2000) Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention provides a bobbin for a superconducting motor that can be expected to ensure cooling performance and structural stability.

[0009] The technical problems to be solved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not described above will be clearly understood by a person having ordinary skill in the art from the description of the present invention. [Means for solving the problem]

[0010] A motor bobbin according to an embodiment of the present invention includes a bobbin body around which a superconducting coil is wound, and a reinforcing body made of reinforced plastic including reinforcing fibers and surrounding a side surface of the bobbin body.

[0011] The bobbin body is made of any one of aluminum, aluminum alloy, iron, iron alloy, stainless steel, and electrical steel plate, and the reinforcing body is made of carbon fiber reinforced plastic (CFRP).

[0012] The bobbin body includes a core portion around which the superconducting coil is wound, and a cover portion that covers the outer casing of the superconducting coil and is spaced from the core portion by the space around which the superconducting coil is wound, and the reinforcing body surrounds the side of the cover portion.

[0013] The reinforcing body preferably surrounds the cover portion of the bobbin body in a region corresponding to the region around which the superconducting coil is wound.

[0014] It is preferable that the reinforcing body surrounds the cover portion of the bobbin at the same height as the height at which the superconducting coil is wound.

[0015] It is preferable that the height of the upper end of the reinforcing body is the same as or lower than the height of the upper end around which the superconducting coil is wound, and the height of the lower end of the reinforcing body is the same as or lower than the height of the lower end around which the superconducting coil is wound.

[0016] The superconducting coil is wound in a racetrack shape having a pair of straight sections parallel to each other and a pair of arc-shaped curved sections respectively connecting one end and the other end of the pair of straight sections, and it is preferable that the reinforcement body is formed so that the ratio of the thickness of the cover part to the thickness of the reinforcement body is 2:1 to 2:2 (the ratio of the thickness of the cover part to the thickness of the reinforcement body is 2 or more and 1 or less) based on the thickness of the cover part covering the straight sections of the superconducting coil. Effect of the Invention

[0017] According to an embodiment of the present invention, a reinforcing member is formed on the side of the bobbin body around which the superconducting coil is wound, using carbon fiber reinforced plastic (CFRP), to structurally protect the side of the bobbin body, thereby making it possible to maximize the performance of the superconducting coil while minimizing the thickness of the bobbin.

[0018] In addition, by suppressing the displacement of the superconducting coil that occurs in a high magnetic field environment, the electrical characteristics and operational stability of the superconducting coil can be ensured.

[0019] In addition, by ensuring cooling performance and structural stability, the superconducting quench phenomenon, in which the superconducting state is destroyed and resistance increases rapidly, can be suppressed, maximizing the performance of the superconducting coil, which is expected to increase the specific output of the superconducting motor. [Brief description of the drawings]

[0020] [Figure 1]11 is a diagram showing the degree of displacement occurring in each region of a bobbin in a superconducting motor using a superconducting coil; FIG. [Diagram 2] 1 is a perspective view showing a bobbin for a superconducting motor according to an embodiment of the present invention; [Diagram 3] 1 is a plan view showing a bobbin for a superconducting motor according to an embodiment of the present invention; [Figure 4] 1 is a cross-sectional view showing a bobbin for a superconducting motor according to an embodiment of the present invention. [Figure 5a] 13 is a diagram showing the degree of stress generated in a side cover portion of a bobbin body according to a comparative example. FIG. [Figure 5b] 11A and 11B are diagrams illustrating the degree of stress generated in a side cover portion of a bobbin body according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings.

[0022] The suffixes "module" and "section" for components used in the following description are given or mixed for the sole consideration of ease of writing the specification, and do not have any meanings or roles that are distinct from each other in themselves.

[0023] In describing the embodiments disclosed herein, if it is determined that a detailed description of related known technologies may obscure the gist of the embodiments disclosed herein, the detailed description will be omitted. In addition, the attached drawings are merely for the purpose of making the embodiments disclosed herein easily understandable, and the technical ideas disclosed herein are not limited by the attached drawings, and should be understood to include all modifications, equivalents, or alternatives included in the ideas and technical scope of the present invention.

[0024] Terms including ordinal numbers, such as "first," "second," etc., may be used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another.

[0025] When an element is referred to as being "coupled" or "connected" to another element, it should be understood that the element may be directly coupled or connected to the other element, or that there may be other intervening elements between them. In contrast, when an element is referred to as being "directly coupled" or "directly connected" to another element, it should be understood that there are no other intervening elements between them.

[0026] A singular expression includes a plural expression unless the context clearly indicates a different meaning.

[0027] In this specification, the terms "comprise" or "have" and the like are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are to be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] First, the bobbin for a superconducting motor according to an embodiment of the present invention can be applied to a bobbin around which a superconducting coil is wound. For example, it can be applied to a bobbin constituting a rotor in an interior permanent magnet type synchronous motor. Of course, the bobbin for a superconducting motor according to an embodiment of the present invention is not limited to a bobbin constituting a rotor, and can be applied to a bobbin constituting a stator when a superconducting coil is applied to the stator.

[0029] In general, an internal-permanent magnet synchronous motor (IPMSM) has a permanent magnet inside and is characterized by its efficiency and high performance.

[0030] In the case of an interior permanent magnet type synchronous motor, when forming a superconducting coil in the rotor, it is necessary to design a case, i.e., a bobbin, to ensure cooling performance and structural stability.

[0031] As mentioned above, superconductivity generates a strong magnetic field of 5 T or more, so when designing the bobbin, it is necessary to take into account the safety of the bobbin against strong magnetic fields.

[0032] In addition, when designing a bobbin, the material and structure are designed together, and bobbin safety is ensured by the strength of the material and the design of the structure.

[0033] 1 is a diagram showing the degree of displacement in each region of a bobbin in a superconducting motor using a superconducting coil. As can be seen from Fig. 1, a superconducting coil 20 is wound around a bobbin 10, and a part of the bobbin 10 surrounds the outside of the superconducting coil 20 to protect the superconducting coil 20 and to separate the superconducting coil 20 from an adjacent pole 100.

[0034] At this time, the bobbin 10 is made of any one of the materials having good thermal conductivity, such as aluminum, aluminum alloy, iron, iron alloy, stainless steel, and electric steel plate. However, a phenomenon occurred in which the superconducting coil 20 was displaced due to a strong magnetic field generated in the superconducting coil 20 while the motor was in operation, and a part of the bobbin 10, particularly the area surrounding the superconducting coil 20 between the bobbin 10 and the adjacent pole 100, which is relatively thin and fragile in the structure of the bobbin 10, was damaged.

[0035] Therefore, in order to prevent the breakage of the weak portion of the bobbin, the thickness and material of the bobbin are the main design factors in the safety design of the bobbin structure.

[0036] However, there are limitations to the properties of the material that forms the bobbin, and increasing the thickness of the bobbin relatively reduces the area of ​​the superconducting coil (limiting the number of turns), resulting in a problem of reduced performance of the superconducting coil.

[0037] Therefore, the present invention provides a bobbin for a superconducting motor, which is expected to ensure cooling performance and structural stability by configuring a reinforcing body surrounding the bobbin body.

[0038] FIG. 2 is an oblique view showing a bobbin for a superconducting motor according to one embodiment of the present invention, FIG. 3 is a plan view showing a bobbin for a superconducting motor according to one embodiment of the present invention, and FIG. 4 is a cross-sectional view showing a bobbin for a superconducting motor according to one embodiment of the present invention.

[0039] As shown in the figure, a motor bobbin according to one embodiment of the present invention includes a bobbin body 10 around which a superconducting coil 20 is wound, and a reinforcing body 30 made of reinforced plastic containing reinforcing fibers and surrounding the sides of the bobbin body 10.

[0040] The bobbin body 10 is a means for winding the superconducting coil 20, and includes a core portion 11 around which the superconducting coil 20 is wound, and a cover portion 12 that is separated from the core portion 11 by a space through which the superconducting coil 20 is wound and covers the outer casing of the superconducting coil 20.

[0041] At this time, the superconducting coil 20 wound around the bobbin body 10 is wound in a racetrack shape having a pair of straight sections parallel to each other and a pair of arc-shaped curved sections respectively connecting one end and the other end of the pair of straight sections.

[0042] As a result, the core 11 of the bobbin body 10 has an outer circumferential surface formed in a racetrack shape so as to correspond to the shape of the inner circumferential surface of the superconducting coil 20 to be wound.

[0043] Similarly, the cover part 12 of the bobbin body 10 has an inner peripheral surface formed in a racetrack shape so as to correspond to the shape of the outer peripheral surface of the superconducting coil 20 wound around the core part 11. However, the cover part 12 of the bobbin body 10 is formed relatively thick in the area covering the curved part of the superconducting coil 20, and is formed relatively thin in the area covering the straight part of the superconducting coil 20.

[0044] Therefore, the outer circumferential surface of the cover portion 12 of the bobbin body 10 is formed in a substantially rectangular shape.

[0045] Meanwhile, the bobbin body 10 is made of any one of aluminum, aluminum alloy, iron, iron alloy, stainless steel, and electrical steel sheet, which have good thermal conductivity. However, although the material from which the bobbin body 10 is made has good thermal conductivity, it lacks rigidity, and the cover part 12 of the bobbin body 10 may be deformed or damaged by the displacement of the superconducting coil 20 during the operation of the motor.

[0046] In order to solve this problem, in this embodiment, a reinforcing member 30 is formed on the outer peripheral surface of the bobbin body 10.

[0047] The reinforcing body 30 is preferably made of a material that has better rigidity and has low thermal contraction and thermal expansion than the material that forms the bobbin body 10. Therefore, the reinforcing body 30 maintains its rigidity while keeping the overall thickness of the bobbin thin.

[0048] For example, the reinforcing body 30 is made of a reinforced plastic containing reinforcing fibers. For example, the reinforcing body 30 is preferably made of carbon fiber reinforced plastic (CFRP).

[0049] Carbon fiber reinforced plastic (CFRP) is a composite material made of carbon fiber and thermosetting resin. Carbon fiber reinforced plastic (CFRP) has properties such as high specific strength, excellent fatigue and creep properties, excellent weather resistance and chemical resistance, and low thermal contraction and thermal expansion. In particular, carbon fiber reinforced plastic (CFRP) is about four times lighter and about nine times stronger than steel.

[0050] On the other hand, in order to prevent the bobbin from being damaged or broken in response to the displacement of the superconducting coil 20, the reinforcing body 30 is preferably formed to surround the cover portion 12 of the bobbin body 10 in the area corresponding to the wound area of ​​the superconducting coil 20.

[0051] At this time, it is preferable that the reinforcing body 30 surrounds the cover portion 12 of the bobbin body 10 at the same height as the wound height of the superconducting coil 20 .

[0052] In addition, it is preferable that the height of the upper end of the reinforcing body 30 is the same as or lower than the height of the upper end around which the superconducting coil 20 is wound, and the height of the lower end of the reinforcing body 30 is the same as or lower than the height of the lower end around which the superconducting coil 20 is wound.

[0053] In particular, since the thickness of the reinforcing member 30 determines the overall thickness of the bobbin, it is preferable to make the thickness as thin as possible while still maintaining the rigidity.

[0054] For example, it is preferable that the thickness of the reinforcing body 30 is set to a ratio of 2:1 to 2:2, based on the thickness of the cover portion 12 that covers the straight portions of the superconducting coil 20, of the thickness of the cover portion: the thickness of the reinforcing body.

[0055] If the thickness of the reinforcement body 30 is thicker than the range in which the ratio of the thickness of the cover part to the thickness of the reinforcement body is set forth, the thickness of the cover part 12 of the bobbin body 10 may become relatively thin or the number of windings of the superconducting coil 20 may decrease, resulting in a problem of reduced motor efficiency.

[0056] Conversely, if the thickness of the reinforcement body 30 is thinner than the range in which the ratio of the thickness of the cover part to the thickness of the reinforcement body is presented, there is a risk that the structural stability of the bobbin required in this embodiment will not be ensured.

[0057] As described above, the reinforcing member 30 is a composite material made of carbon fibers and a thermosetting resin, and the carbon fibers may be long fibers having a relatively long fiber length or continuous fibers oriented in a certain direction. Of course, the carbon fibers may be in the form of woven continuous fibers.

[0058] Since the reinforcing body 30 has a predetermined directionality, the reinforcing body can be formed by being wound so as to wrap the outer circumferential surface of the bobbin body 10 along the direction of the carbon fiber.

[0059] At this time, the carbon fiber reinforced plastic constituting the reinforcing body 30 is preferably manufactured into a sheet or tape shape and wound around the outer circumferential surface of the bobbin body 10. At this time, the winding direction is preferably clockwise or counterclockwise based on the plan view of FIG.

[0060] Next, the present invention will be described with reference to comparative examples and examples.

[0061] In the comparative example, a bobbin was used that was made up of only the bobbin body without a reinforcing member. In this case, the thickness of the bobbin body, i.e., the thickness of the region covering the straight portion of the superconducting coil, was set to 3 mm.

[0062] In contrast, in the embodiment, a reinforcing body was formed on the outer circumferential surface of the bobbin body according to the present invention. At this time, the thickness of the bobbin body, i.e., the thickness of the region covering the straight portion of the superconducting coil, was 2 mm, and the thickness of the reinforcing body was 1 mm.

[0063] The degree of stress generated in the straight portion of the bobbin body when the motor was operated was measured for the prepared bobbin, and the results are shown in FIGS. 5a and 5b.

[0064] FIG. 5a is a diagram showing the degree of stress generated in a side cover portion of a bobbin body according to a comparative example, and FIG. 5b is a diagram showing the degree of stress generated in a side cover portion of a bobbin body according to an embodiment.

[0065] As can be seen from FIG. 5a and FIG. 5b, in the comparative example, the stress generated in that region was 105.01 MPa, and in the example, the stress generated in that region was 93.953 MPa.

[0066] Therefore, it was confirmed that the stress generated in the side cover portion of the bobbin body in the embodiment was reduced by about 10.5% compared to the comparative example.

[0067] Although the present invention has been described with reference to the accompanying drawings and the above-mentioned preferred embodiment, the present invention is not limited thereto, but is limited by the following claims. Therefore, those skilled in the art may make various modifications and changes to the present invention without departing from the technical spirit of the following claims. [Explanation of symbols]

[0068] 10 Bobbin body 11 Core 12 Cover part 20 Superconducting coil 30 Reinforcement

Claims

1. A bobbin body on which a superconducting coil is wound, A bobbin for a motor comprising: a reinforcing body made of reinforced plastic containing reinforcing fibers and surrounding a side surface of the bobbin body.

2. The bobbin body is made of any one of aluminum, aluminum alloy, iron, iron alloy, stainless steel, and electrical steel sheet; The motor bobbin according to claim 1 , wherein the reinforcing member is made of carbon fiber reinforced plastic (CFRP).

3. The bobbin body includes: a core around which the superconducting coil is wound; a cover portion that covers an outer shell of the superconducting coil and is spaced from the core portion by a space in which the superconducting coil is wound, The motor bobbin according to claim 1 , wherein the reinforcing member surrounds a side surface of the cover portion.

4. 4. The motor bobbin according to claim 3, wherein the reinforcing member surrounds the cover portion of the bobbin body in a region corresponding to a region where the superconducting coil is wound.

5. 5. The motor bobbin according to claim 4, wherein the reinforcing member surrounds the cover of the bobbin at the same height as the height at which the superconducting coil is wound.

6. The height of the upper end of the reinforcing body is equal to or lower than the height of the upper end of the wound superconducting coil, 5. The motor bobbin according to claim 4, wherein the height of the lower end of the reinforcing member is equal to or lower than the height of the lower end around which the superconducting coil is wound.

7. the superconducting coil is wound in a racetrack shape having a pair of parallel straight portions and a pair of arc-shaped curved portions respectively connecting one end and the other end of the pair of straight portions, 4. The motor bobbin of claim 3, wherein the reinforcing body is formed such that the ratio of the thickness of the cover part to the thickness of the reinforcing body is 2:1 to 2:2 based on the thickness of the cover part covering the straight portion of the superconducting coil.

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