JP2019140768A - Sheet material for rotating electric machine - Google Patents

Abstract

To provide a sheet material for a rotating electric machine capable of suppressing protrusion from a gap between a stator and a coil.SOLUTION: A sheet material 10 includes: a sheet-shaped base material 11; a first adhesive layer 12 formed on one portion of the base material; and a second adhesive layer 13 formed on the other portion of the base material, in which, in the first adhesive layer, first foaming beads 12d in which a first expansion agent 12b is encapsulated in a first shell 12c made of a thermoplastic resin are dispersed in an adhesive, in the second adhesive layer, second foaming beads 13d in which a second expansion agent 13b is encapsulated in a second shell 13c made of a thermoplastic resin are dispersed in the adhesive, and the first and second foam beads are configured so that the first and second foaming beads expand, the first shell of the first foaming beads is destroyed and the second shell of the second foam beads is broken, when the sheet material is heated while being arranged between a stator 2 and a coil 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet material for a rotating electrical machine, and more particularly to a sheet material disposed between a stator and a coil by arranging a coil in a slot formed in the stator.

  Conventionally, a slot is formed in a stator of a rotating electrical machine, and a coil is disposed in the slot. A sheet material or the like may be used to fix the coil in the slot. For example, Patent Document 1 proposes an expansion sheet that is disposed between a stator and a coil in a slot and expands by heating, and the coil side expands with a higher volume increase than the stator side. ing.

JP 2013-236468 A

  In the sheet material described in Patent Document 1, the expansion sheet is disposed between the stator and the coil, and by heating the expansion sheet, the gap between the coil and the inner wall surface of the slot can be eliminated or reduced. Due to the dimensional tolerance of the coil and the like, there is a possibility that the expanded sheet protrudes from the slot when heated.

  The present invention has been made in view of such a problem, and even when the sheet material expands when the sheet material for a rotating electrical machine is heated, the sheet material protrudes from the gap between the stator and the coil. It is providing the sheet | seat material for rotary electric machines which can be suppressed.

  In view of the above problems, a sheet material for a rotating electrical machine according to the present invention has a coil disposed in a slot formed in a stator of the rotating electrical machine, and the rotating electrical machine disposed between the stator and the coil. A sheet material, the sheet material is a sheet-like base material, a first adhesive layer formed on one of the base material, a second adhesive layer formed on the other of the base material, In the first adhesive layer, a first foaming bead in which a first expansion agent is encapsulated in a first shell made of a thermoplastic resin is dispersed in the adhesive, and the first adhesive layer is dispersed in the first adhesive layer. In the adhesive layer 2, a second foaming bead in which a second expansion agent is encapsulated in a second shell made of a thermoplastic resin is dispersed in the adhesive, and the sheet material is used as the stator and the coil. When the first and second foaming foams are heated The first and second foams so that the first shell of the first foam beads is destroyed and the second shell of the second foam beads is not destroyed. It is characterized by comprising beads for use.

  According to the sheet material for a rotating electrical machine of the present invention, when the sheet material is heated while being disposed between the stator and the coil, the sheet material is dispersed in the first and second adhesive layers between the stator and the coil. The first and second foaming beads expand (the sheet material expands). Specifically, the first and second expansion agents encapsulated in the first and second shells are expanded by heating, and as a result, the first and second foaming beads expand, and as a result, the first And the second adhesive layer expands (expands). At this time, the first adhesive layer is pressed to the expanded second adhesive layer through the base material, and the first shell of the first foaming beads dispersed in the first adhesive layer is destroyed. (Bubbles). On the other hand, the second shell of the second foaming beads is not destroyed.

  Thereby, the 1st swelling agent included in the 1st shell slips out from the 1st adhesion layer, and the volume of the 1st adhesion layer contracts. In this way, it is possible to suppress the protrusion of the adhesive layer from the slot due to overexpansion (overexpansion) of the foaming beads by the expansion agent. In addition, since the sheet material is filled between the stator and the coil in the slot when the first adhesive layer is once foamed, it is possible to suppress poor filling of the sheet material and to stabilize the coil between the teeth. And can be fixed.

It is principal part sectional drawing of the state which has arrange | positioned the sheet | seat material for rotary electric machines of one Embodiment of this invention to the slot formed in the stator of the rotary electric machine. It is principal part sectional drawing by which the coil and the sheet | seat material are arrange | positioned in the slot shown in FIG. 1, (a) shows the state before a heating, (b) is principal part sectional drawing which shows the state after a heating. It is a graph which shows the relationship between temperature rising temperature and the layer thickness of an adhesive layer. (A) is principal part sectional drawing which shows the state of the filling failure of the 1st and 2nd contact bonding layers after a heating, (b) is a principal part which shows the state which the 1st and 2nd contact bonding layers after a heating protruded It is sectional drawing.

  Hereinafter, an embodiment of a sheet material for a rotating electrical machine according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a main part in a state where a sheet material 10 for a rotating electrical machine 1 according to the present embodiment is disposed in a slot 4 formed in a stator 2 of the rotating electrical machine 1. The positional relationship is shown. 2A is a cross-sectional view of a main part showing a state before heating in which the coil 20 and the sheet material 10 are arranged in the slot 4 shown in FIG. 1, and FIG. 2B is a main part showing the state after heating. FIG.

  The rotating electrical machine 1 in which the sheet material 10 according to the present embodiment is disposed is a three-phase AC motor, and in FIG. The part is shown. Therefore, in another portion, there are a portion where the U phase and the W phase are in contact at the coil end, and a portion where the V phase and the W phase are in contact at the coil end. Of course, the rotating electrical machine is not limited to a three-phase AC motor.

  Specifically, the main part sectional view of FIG. 1 is a sectional view showing a slot 4 formed in the stator 2 of the rotating electrical machine 1 and a coil 20 arranged in the slot 4. The slot 4 is a space between teeth 5 and 5 extending in the center direction of the stator 2, and the coil 20 is arranged in this space. When the coil 20 is disposed in the slot 4 sandwiched between the teeth 5 and 5, a gap 6 is formed between the coil 20 and the teeth 5 and 5 (see FIG. 2A). A sheet material 10 is disposed in the gap 6. The coil 20 is formed by stacking and fixing a plurality of single coils 21, 21... Having a rectangular cross-sectional shape.

  The sheet material 10 includes a sheet-like base material 11, a first adhesive layer 12 formed on one surface of the base material 11, and a second adhesive layer 13 formed on the other surface of the base material 11. It is equipped with. Although it will not specifically limit as the base material 11 if it has insulation and flexibility, It is a resin-made film, The textile fabric or nonwoven fabric etc. which consist of resin-made fibers may be sufficient.

  The first adhesive layer 12 formed on one surface side of the base material 11 is, for example, a first shell 12c made of a thermoplastic resin and a first expansion agent 12b on a thermal expansion type epoxy adhesive 12a. The first foam beads 12d encapsulated therein are dispersed.

  The first expansion agent 12b is an expansion agent made of hydrocarbon, and expands and gasifies when heated. The first shell 12c is made of, for example, polypropylene or acrylic resin, and includes the first expansion agent 12b. As the first foaming beads 12d, foaming beads having lower heat resistance than the second foaming beads 13d are used.

  The foaming beads with low heat resistance are gasified by the first expansion agent 12b included during heating, the first shell 12c of the first foaming beads 12d is destroyed, and gasified from the first shell 12c. The expanded swelling agent 12b comes off and bubbles. Specifically, for example, by making the thickness of the first shell 12c thinner than the thickness of the second shell 13c described later, the first shell 12c can be easily destroyed during heating. In particular, as will be described later, by increasing the heating rate during heating, such a phenomenon can be manifested before the adhesive 12a is thermally cured.

  The second adhesive layer 13 formed on the other surface side of the base material 11 includes, for example, a thermal expansion type epoxy adhesive 13a and a second expansion agent 13b made of a thermoplastic resin as a second shell 13c. The second foaming beads 13d encapsulated in are dispersed.

The second expansion agent 13b is an expansion agent made of hydrocarbon, and expands and gasifies when heated. The second shell 13c is made of, for example, polypropylene or acrylic resin, and includes the second expansion agent 13b. As the second foaming beads 13d, foaming beads having higher heat resistance than the first foaming beads 12d are used.

  In this highly heat-resistant foaming bead, the second expansion agent 13b encapsulated after heating is gasified, but the second shell 13c of the foaming bead is not destroyed by heating described later, and the gas does not escape. It is. Specifically, as described above, the second shell 13c can be made harder to break by making it thicker than the first shell 12c.

  In this embodiment, the thickness of the first shell 12c is made thinner than the thickness of the second shell 13c, so that the first shell 12c is easily destroyed during heating. By making the heat resistant temperature (softening point) of the resin of the shell 12c lower than the heat resistant temperature (softening point) of the resin of the second shell 13c, the first shell 12c may be easily broken during heating. In addition, by using an expansion agent having a higher expansion coefficient than the second expansion agent 13b included in the second shell 13c, for the first expansion agent 12b included in the first shell 12c. The first shell 12c may be easily broken during heating.

  As described above, when the sheet material 10 is heated while being disposed between the stator 2 and the coil 20, the first and second foaming beads 12d and 13d expand and the first foaming beads 12d. The first and second foaming beads 12d and 13d can be configured so that the first shell 12c is not destroyed and the second shell 13c of the second foaming bead 13d is not destroyed.

  Here, an example of the first adhesive layer 12 and the second adhesive layer 13 described above will be described in more detail with reference to FIG. The second adhesive layer 13 using the second foaming beads 13d having high heat resistance rapidly expands to a temperature rising rate of about 15 to 20 ° C./min during heating, and the layer thickness is 270 to 270. When the temperature rise is around 120 ° C./min, the layer thickness exceeds 300 mm. As described above, the second adhesive layer 13 has a characteristic that the layer thickness increases with an increase in the heating rate, but basically the layer thickness does not decrease. That is, the second shell 13c of the second adhesive layer 13 is not broken regardless of the above-described temperature increase rate.

  On the other hand, when the first adhesive layer 12 using the first foaming beads 12d having low heat resistance is heated, the temperature rising rate rapidly expands to about 15 to 20 ° C./min and expands. The amount is about 190 mm, and the amount of expansion decreases to about 100 mm when the temperature rising rate is around 120 ° C./min. As described above, the first adhesive layer 12 has a characteristic that the first shell 12c is destroyed and the layer thickness of the first adhesive layer 12 is reduced when the temperature increase rate is equal to or higher than a certain temperature increase rate. is there.

  As described above, the first adhesive layer 12 formed on one of the base materials 11 of the sheet material 10 and the second adhesive layer 13 formed on the other base material 11 are heated when heated. The first adhesive layer 12 has a property of contracting after rapidly expanding, and the second adhesive layer 13 has a property of maintaining this expansion even after rapidly expanding. ing.

  The operation of the sheet material 10 for a rotating electrical machine of the present embodiment configured as described above will be described below with reference to FIG. As shown in FIG. 2A, a sheet material 10 for a rotating electrical machine composed of a base material 11, a first adhesive layer 12, and a second adhesive layer 13 includes a slot 4 formed in the stator 2. In the state of being arranged between the coil 20, a gap 6 is formed. The gap 6 is formed uniformly on both sides of the sheet material 10 in the figure, but varies on both sides of the sheet material 10 depending on the shape of the sheet material 10.

  In this way, by forming the gap 6, the sheet material 10 can be easily inserted and arranged between the stator 2 and the coil 20. When the sheet material 10 is heated in this state, the first adhesive layer 12 expands and then contracts, and the second adhesive layer 13 expands.

  Specifically, the first adhesive layer 12 has a thick layer t1 in a state before heating, and when heated, for example, at a heating rate of 120 ° C./min from room temperature, The first expansion agent 12b expands and gasifies, and the first shell 12c of the first foaming bead 12d expands. On the other hand, the thickness of the second adhesive layer 13 is T1 in a state before heating, and when heated, the second expansion agent 13b expands and gasses when heated from room temperature at a heating rate of 120 ° C./min. And the second shell 13c of the second foaming bead 13d expands.

  When further heated, the second shell 13c of the second foaming bead 13d is not destroyed and further expands. The first adhesive layer 12 is pressed against the second adhesive layer 13 via the base material 11, and the first shell 12c is destroyed (bubbles broken). At this time, the gasified first expansion agent 12b is released from the first shell 12c, and the volume of the first adhesive layer 12 is contracted by releasing the gas, so that the layer thickness of the first adhesive layer 12 is reduced. Becomes t2. At this time, the layer thickness of the second adhesive layer 13 is T2.

  As described above, since the first adhesive layer 12 and the second adhesive layer 13 formed on the front and back surfaces of the sheet material 10 have different expansion characteristics (foaming characteristics), they are formed on the stator 2 of the rotating electrical machine 1. When the coil 20 is disposed in the slot 4 and heated, the first adhesive layer 12 and the second adhesive layer 13 are overexpanded (overfoamed), and the gap 6 between the stator 2 and the coil 20 is increased. It is possible to suppress the protrusion.

  Further, since the sheet material 10 is filled between the stator 2 and the coil 20 in the slot 4 when the first adhesive layer 12 is once foamed, the gap 6 between the stator 2 and the coil 20 is filled. Incomplete filling can be suppressed. Furthermore, the coil 20 can be stably fixed between the teeth 5 and 5 of the stator 2.

  Next, without using the sheet material 10 of the present embodiment, a conventional sheet material in which a normal adhesive layer is formed on one side of the base material and a normal adhesive layer is formed on the other side of the base material is used. The case where the adhesive layer is poorly filled and the case where the adhesive layer protrudes will be described in detail with reference to FIGS. 4 (a) and 4 (b).

  A sheet material 30 shown in FIG. 4A includes a first adhesive layer 32 formed on one surface of the base material 31, a second adhesive layer 33 formed on the other surface of the base material 31, It has. The first adhesive layer 32 formed on one surface of the base material 31 has a first foaming material in which a first expansion agent 32b is included in a first shell 32c made of a thermoplastic resin in an adhesive 32a. The beads 32d are dispersed, and the second adhesive layer 33 formed on the other surface of the substrate 31 has an adhesive 33a and a second expansion agent 33b and a second shell 33c made of a thermoplastic resin. The second foaming beads 33d encapsulated in are dispersed.

  When the sheet material 30 is heated in a state where it is disposed between the stator 2 and the coil 20, the first foaming beads 32d and the second foaming beads 33d expand, and both of these foaming beads are destroyed. (Bubble breaks). That is, when the first foaming bead 32d and the second foaming bead 33d are heated to reach a predetermined temperature, the encapsulated first expansion agent 32b and the second expansion agent 33b are gasified, and the first Since both the shell 32c and the second shell 33c are destroyed and the encapsulated expansion agent is released, the volume of the first adhesive layer 32 and the second adhesive layer 33 contracts and the thickness decreases. For this reason, the gap 6 remains between the stator 2 and the coil 20, and a filling defect occurs.

  On the other hand, the sheet material 40 shown in FIG. 4B has a first adhesive layer 42 formed on one surface of the base material 41 and a second adhesive layer 43 formed on the other surface of the base material 41. And. The first adhesive layer 42 formed on one surface of the substrate 41 has a first foaming material in which a first expansion agent 42b is included in a first shell 42c made of a thermoplastic resin in an adhesive 42a. The beads 42d are dispersed, and the second adhesive layer 43 formed on the other surface of the base material 41 has an adhesive 43a and a second expansion agent 43b as a second shell 43c made of a thermoplastic resin. The second foaming beads 43d encapsulated in are dispersed.

  When the sheet material 40 is heated in a state where it is disposed between the stator 2 and the coil 20, the first foaming beads 42d and the second foaming beads 43d expand, and both of these foaming beads are destroyed. It does not (bubble break). That is, even if the first shell 42c and the second shell 43c are heated and reach a predetermined temperature, the first shell 42c and the second shell 43c are not destroyed, and the included first expansion agent 42b and second expansion agent 43b are gasified. Since the first shell 42c and the second shell 43c are not released, the first adhesive layer 42 and the second adhesive layer 43 do not shrink in volume and do not decrease in thickness. For this reason, protrusions 42e and 43e protruding from the gap 2 between the stator 2 and the coil 20 are generated.

  In the sheet material 10 of this embodiment, as described above, the first foaming beads 12d and the second foaming beads 13d expand, and the first shell 12c of the first foaming beads 12d is destroyed. Since the first foaming beads 12d and the second foaming beads 13d are configured so that the second shell 13c of the second foaming beads 13d is not broken, as shown in FIG. Thus, there is an effect that no poor filling occurs and the adhesive layer shown in FIG. 4B does not protrude.

  Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention described in the claims. Design changes can be made. For example, in the sheet material, a first adhesive layer is formed on one of the substrates, and a second adhesive layer is formed on the other of the substrates, and the shell of one of the two adhesive layers is a shell. Needless to say, it is sufficient if it is configured to be destroyed.

  Further, as the first adhesive layer using foaming beads having low heat resistance and the second adhesive layer using foaming beads having high heat resistance, the thicknesses of the first shell and the second shell are used. However, the present invention is not limited to this, and the heat resistance may be set by changing the material of the shell and the hardness of the shell.

1: rotating electric machine, 2: stator, 4: slot, 5: teeth, 6: gap, 10: sheet material for rotating electric machine, 11: sheet-like base material, 12: first adhesive layer, 12a: adhesive 12b: first expansion agent, 12c: first shell, 12d: first foaming beads, 13: second adhesive layer, 13a: adhesive, 13b: second expansion agent, 13c: second Shell, 13d: second foaming bead, 20: coil

Claims (1)

A coil is disposed in a slot formed in a stator of a rotating electrical machine, and is a sheet material for a rotating electrical machine disposed between the stator and the coil,
The sheet material includes a sheet-like base material, a first adhesive layer formed on one of the base materials, and a second adhesive layer formed on the other base material,
In the first adhesive layer, the first foaming beads in which the first expansion agent is encapsulated in the first shell made of a thermoplastic resin are dispersed in the adhesive,
In the second adhesive layer, a second foaming bead in which a second expansion agent is encapsulated in a second shell made of a thermoplastic resin is dispersed in the adhesive,
When the sheet material is heated while being disposed between the stator and the coil, the first and second foam beads expand and the first shell of the first foam beads. The first and second foaming beads are configured so that the second shell of the second foaming beads is not destroyed and the second shell of the second foaming beads is destroyed.

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