slot lining

Abstract

The present invention is a slot liner, which is composed of a laminated sheet with an adhesive layer laminated on the surface of an insulating sheet body. The slot liner is used to be clamped between the inner wall surface of a slot provided in the stator core of a rotating electric machine and a coil accommodated in the slot. The laminated sheet is folded to form a fold line. The slot liner has an overlapping portion, and the overlapping portion overlaps with the first and second regions of the adjacent laminated sheets via the fold line. The slot liner is arranged in a manner such that the overlapping portion is clamped between the inner wall surface of the slot and the coil. The slot liner is respectively provided with the adhesive layer on one side abutting the inner wall surface of the slot and the other side abutting the coil.

Description

Technical Field

[0001] The present invention relates to a slot liner, and more particularly to a slot liner having an adhesive layer. Background Art

[0002] Conventionally, rotating electrical machines such as motors and generators have coils formed by winding insulatingly coated varnished wire (winding wire) into an oblong shape. The insulatingly coated varnished wire is formed by applying a resin composition such as enamel to thin copper wire.

[0003] In the motor, the magnetic field generated by the coil becomes rotational power, and in the generator, the change in the magnetic field is converted into electromotive force through the coil.

[0004] In the rotating electrical machine described above, the coil is composed of, for example, a plurality of segmented conductors connected to each other. Typically, the coil is mounted on a component formed by stacking magnetic steel plates, which is called a stator core or a rotor core.

[0005] In the rotating electric machine described above, the core such as the stator core or the rotor core has a plurality of slots, and the coils are housed in the respective slots.

[0006] In this rotating electrical machine, a slot liner for ensuring insulation between the coil and the inner wall surface of the slot is housed in each slot together with the coil. More specifically, the slot liner is housed in the slot while surrounding the coil.

[0007] As such a slot liner, a slot liner having adhesive layers on both sides of a base material is disclosed in Patent Document 1 listed below. The adhesive layer of the slot liner described in Patent Document 1 contains a thermosetting resin and a foaming agent.

[0008] In the slot liner described in Patent Document 1, the adhesive layers on both sides of the base material are constructed as described above. Therefore, for example, as the temperature rises due to induction heating of the stator core or current flowing through the conductors (segment conductors) forming the coils, the foaming agent begins to foam, causing the adhesive layers on both sides of the base material to expand. This causes the adhesive layer on one side to contact the inner wall of the slot (i.e., the core) and the adhesive layer on the other side to contact the coils. The thermosetting resin then cures, securing the coils within the slots.

[0009] Therefore, for example, even when vibration occurs in the rotating electrical machine, the coil can be prevented from coming out of the slot.

[0010] Prior art literature

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-244596 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] Furthermore, the segment conductor before coil formation is formed by forming a slot liner into a cylindrical shape along the inner peripheral surface of the slot and arranging it in the slot, and then being housed inside the cylindrical slot liner.

[0014] Therefore, when the segmented conductor is housed inside the cylindrical slot liner, a certain amount of clearance needs to be provided between the inner surface of the slot liner and the segmented conductor in order to suppress interference between the inner surface of the slot liner (i.e., the adhesive layer on the other side) and the segmented conductor. After the segmented conductor is housed inside the cylindrical slot, in order to fill the certain amount of clearance, the adhesive layer needs to contain a large amount of foaming agent and needs to be foamed to a large extent.

[0015] However, if the adhesive layer is foamed to a large extent, many voids will be formed in the adhesive layer, which may reduce the bulk strength of the adhesive layer and thus may reduce the adhesive force of the adhesive layer.

[0016] Therefore, a slot liner capable of suppressing a decrease in the adhesive strength of the adhesive layer is desired.

[0017] Therefore, an object of the present invention is to provide a slot liner capable of suppressing a decrease in the adhesive force of an adhesive layer.

[0018] Means for solving problems

[0019] The slot liner of the present invention,

[0020] It is composed of a laminated sheet with an adhesive layer laminated on the surface of an insulating sheet.

[0021] The slot liner is used to be sandwiched between the inner wall surface of the slot provided in the stator core of the rotating electrical machine and the coil accommodated in the slot.

[0022] The laminate sheet is folded to form a fold line, and the slot liner has an overlapping portion, in which the first region and the second region of the adjacent laminate sheet overlap via the fold line, and the slot liner is arranged so that the overlapping portion is sandwiched between the inner wall surface of the slot and the coil.

[0023] The slot liner has the adhesive layer disposed on one side surface that contacts the inner wall surface of the slot and the other side surface that contacts the coil.

[0024] In the slot liner, it is preferable that the fold line be arranged so as to face outward of the slot.

[0025] In the slot liner, preferably,

[0026] In a state before being folded, the slot liner has a length that protrudes outward from both ends of the slot when being sandwiched between the inner wall surface of the slot and the coil.

[0027] The slot liner has a first fold line on one end edge side of the slot and a second fold line on the other end edge side of the slot.

[0028] The slot liner includes the first region extending from the first fold line to the second fold line, the second region adjacent to the first region via the first fold line, and the third region adjacent to the first region via the second fold line.

[0029] The slot liner includes a first overlapping portion formed by overlapping the first region and the second region, and a second overlapping portion formed by overlapping the first region and the third region.

[0030] In the slot liner, preferably,

[0031] In a state before being folded, the slot liner has a length that protrudes outward from both ends of the slot when being sandwiched between the inner wall surface of the slot and the coil.

[0032] The slot liner has a first fold line on one end edge side of the slot and a second fold line on the other end edge side of the slot.

[0033] The slot liner includes the first region extending from the first fold line to the second fold line, the second region adjacent to the first region via the first fold line, and the third region adjacent to the first region via the second fold line.

[0034] The slot liner has an overlapping portion having a three-layer structure in which the first region to the third region overlap.

[0035] In the slot liner,

[0036] It is preferable that an adhesive layer is laminated only on one surface of the insulating sheet.

[0037] In the slot liner,

[0038] The adhesive layer preferably contains a resin and a foaming agent dispersed in the resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic perspective view of a stator of a drive motor for an HEV or EV.

[0040] Figure 2 This is a schematic top view of the stator core.

[0041] Figure 3 yes Figure 2 Magnified view of part A.

[0042] Figure 4 It is a cross-sectional view showing an example of the structure of a slot liner.

[0043] Figure 5 This is a diagram showing an example of forming an overlapping portion in a slot liner and an example of inserting the slot liner. Figure 5 (a) and Figure 5 (b) is a diagram showing an example of forming an overlapping portion in a slot liner. Figure 5 (c) is a diagram showing an example of a clamped slot liner.

[0044] Figure 6 These are diagrams showing another example of forming an overlapping portion in a slot liner and another example of interposing a slot liner. Figure 6 (a) and Figure 6 (b) is a diagram showing another example of forming an overlapping portion in a slot liner. Figure 6 (c) is a diagram showing another example of a clamped slot liner.

[0045] Figure 7 These are diagrams showing still another example of forming an overlapping portion in a slot liner and still another example of interposing a slot liner. Figure 7 (a) and Figure 7 (b) is a diagram showing still another example of forming an overlapping portion in a slot liner. Figure 7 (c) is a diagram showing still another example of a clamped slot liner.

[0046] Description of Reference Signs

[0047] 1 stator, 10 stator core, 11 slot, 12 plate-like protrusion (tooth), 20 coil, 21 segmented conductor, 40 slot liner, 41 insulating sheet, 42 adhesive layer, 10a upper end surface, 10b lower end surface, 11a linear opening, 11b opening, 12a widened portion, 21a head, 21b leg, 21bx front end, 21x connecting portion, 40a overlapping portion, 41a base sheet, 41b adhesive layer, 41c paper-like sheet, AD rotation axis direction, RD circumferential direction, DD radial direction, L1 fold line, L2 first fold line, L3 second fold line, R1 first region, R2 second region, R3 third region, O1 overlapping portion of two-layer structure, O2 first overlapping portion, O3 second overlapping portion, O4 overlapping portion of triple structure. DETAILED DESCRIPTION

[0048] Embodiments of the present invention will be described with reference to the accompanying drawings.

[0049] Here, a case where the rotating electric machine is a driving motor of a hybrid electric vehicle (HEV) or an electric vehicle (EV) will be described as an example.

[0050] To explain in more detail, here, the driving motor has a rotor and a stator, wherein the rotor has a permanent magnet and the stator has a coil, and the driving motor has a coil formed by a segment conductor. The case where the slot liner of the present invention is used for insulation between the coil and the iron core in the stator is explained as an example.

[0051] Figure 1 1 is a perspective view of a stator 1 of a driving motor according to the present embodiment. As shown in the figure, the stator 1 includes a stator core 10 and a coil 20 .

[0052] Figure 2 This is a plan view of the stator 1 as viewed from the direction of the rotation axis of the rotor (not shown) (arrow AD). Figure 3 It means that multiple coils 20 are accommodated in Figure 2 The cross-sectional view of the state of the portion A of the stator core 10 is shown.

[0053] As shown in these figures, in the stator 1 , a plurality of slots 11 are formed on the inner peripheral surface side of a cylindrical stator core 10 .

[0054] The stator 1 includes a stator core 10 and a plurality of coils 20 accommodated in a plurality of slots 11 formed in the stator core 10 .

[0055] Each slot 11 of the plurality of slots 11 is arranged along the rotation axis direction of the stator core 10 ( Figure 1 AD) extends, and each slot 11 is arranged in the circumferential direction ( Figure 1 The stator core 10 is arranged on the RD) with a certain distance between them.

[0056] The slots 11 are formed over the entire length of the stator core 10 in the rotation axis direction AD, and are located on one end surface 10a ( Figure 1 An opening portion 11b having the same shape as the cross-sectional shape of the slot 11 is formed on the upper side (hereinafter referred to as the "upper end surface 10a") and the other end surface 10b (hereinafter referred to as the "lower end surface 10b").

[0057] In the stator core 10 , as described above, the plurality of slots 11 are arranged in parallel, and therefore, the space between adjacent slots 11 forms a plate-shaped protrusion 12 .

[0058] The plate-like protrusion 12 (hereinafter referred to as "tooth protrusion 12") is formed in a radial direction ( Figure 1 DD) forms multiple inner protruding states.

[0059] In addition, if Figure 2 and 3 As shown, the tooth protrusion 12 has a widened portion 12 a at its protruding front end portion, which is widened in the circumferential direction RD of the stator core 10 , and its cross-sectional shape is T-shaped.

[0060] Therefore, the width of the slot 11 is narrowed on the inner peripheral surface side of the stator core 10 , and only a minute linear opening 11 a is formed.

[0061] The coil 20 is composed of a plurality of segment conductors 21 connected to each other.

[0062] In addition, if Figure 1 As shown, the segment conductor 21 before forming the coil is a rectangular varnish wire bent into a U-shape and has two leg portions 21 b and a head portion 21 a connecting the two leg portions 21 b.

[0063] The segment conductor 21 of the present embodiment has a copper wire exposed portion from which the insulating film is peeled at the tip end portion 21bx of the leg portion 21b on the opposite side to the head portion 21a.

[0064] The coil 20 of this embodiment is manufactured as follows: after the leg portion 21b of the segment conductor 21 is inserted through the opening 11b of the slot 11 in the upper end surface 10a of the stator core 10, the tip end 21bx of the leg portion 21b is exposed from the lower end surface 10b of the stator core 10. Then, the leg portion 21b of one segment conductor 21 is electrically connected to the leg portion 21b of another segment conductor 21 at the exposed copper wire portion to form a connecting portion 21x, and this connecting portion 21x is further insulated.

[0065] Furthermore, the two leg portions 21 b of one segment conductor 21 are respectively inserted into different slots 11 .

[0066] The coil 20 of this embodiment is manufactured as described above. Therefore, the stator 1 of this embodiment has an upper coil end portion formed by the head portion 21a of the segment conductor 21 on the upper end surface 10a side of the stator core 10, and has a lower coil end portion formed by the connecting portion 21x formed by connecting the leg portions 21b on the lower end surface 10b side.

[0067] like Figure 3 As shown, four leg portions 21 b of the segment conductors 21 forming the coils 20 are respectively accommodated in the slots 11 of the stator core 10 (each of the four leg portions 21 b of one side of the segment conductors 21 is accommodated). In each slot 11, a total of four leg portions 21 b are accommodated in a state of being arranged in a row from the inner peripheral surface side to the outer peripheral surface side.

[0068] like Figure 3As shown, the slot liner 40 of this embodiment is interposed between the four leg portions 21 b and the inner wall surface of the slot 11 .

[0069] In addition, if Figure 4 As shown, the slot liner 40 of this embodiment is composed of a laminated sheet body having an adhesive layer 42 laminated on the surface of an insulating sheet body 41 . More specifically, the slot liner 40 is composed of a laminated sheet body having an adhesive layer 42 laminated on one side surface of the insulating sheet body 41 .

[0070] Therefore, as described above, the slot liner 40 of this embodiment is folded in the following manner: when the slot liner 40 is clamped between the four leg portions 21b and the inner wall surface of the slot 11, an adhesive layer 42 is respectively provided on one side surface abutting the inner wall surface of the slot 11 and the other side surface abutting the four leg portions 21b before the coil is formed.

[0071] Reference Figure 5 An example of the folded slot liner 40 according to this embodiment and an example of inserting the folded slot liner 40 into the slot 11 will be described.

[0072] In addition, Figure 5 In (c), the slot liner 40 is in a state of being accommodated in the slot 11, but the slot 11 is omitted.

[0073] In addition, Figure 5 In (c), in order to facilitate viewing of the interior of the slot liner 40 accommodated in the slot 11, a portion of the cylindrical side surface is shown opened.

[0074] In addition, a portion of the cylindrical side is not open. Figure 3 shown.

[0075] First, if Figure 5 As shown in (a) and (b) of FIG. 1 , the first region R1 and the second region R2 of the adjacent laminated sheets are folded along a fold line L1 so that the adhesive layer 42 is disposed on the one side surface and the other side surface, that is, so that the adhesive layer 42 is disposed on the outer side of the folded sheet. In this embodiment, the first region R1 and the second region R2 of the adjacent laminated sheets are folded along a fold line L1 to form the overlapping portion O1 of the two-layer structure.

[0076] Next, if Figure 5 As shown in (c), the folded slot liner 40 is formed into a cylindrical shape and housed in the slot 11. Then, the four legs 21b are inserted into the cylindrical slot liner 40. Thus, the slot liner 40 is sandwiched between the inner wall of the slot 11 and the four legs 21b before forming the coils, with the four legs 21b bundled together at once by the overlapping portion O1 of the two-layer structure.

[0077] Furthermore, in this embodiment, the folded slot liner 40 is housed within the slot 11 with its fold line L1 facing outward of the slot 11. Furthermore, the folded slot liner 40 is housed within the slot 11 with its front end, where the first region R1 and the second region R2 connect, facing outward. More specifically, the folded slot liner 40 is housed within the slot 11 with its fold line L1 positioned on the side where the four legs 21b are inserted. Therefore, when the four legs 21b are inserted into the cylindrical slot liner 40, interference between the four legs 21b and the portion of the slot liner 40 that expands due to its rebound function can be suppressed.

[0078] The slot liner 40, with the two-layer overlapping portion O1 formed thereon as described above, is arranged longitudinally aligned with the leg portions 21 b of the segment conductor 21 along the longitudinal direction thereof and arranged in the slot 11 so as to surround the four leg portions 21 b at least once. Furthermore, the slot liner 40 is arranged in the slot 11 such that both ends thereof in the rotation axis direction AD protrude outward from the upper end surface 10 a and the lower end surface 10 b of the stator core 10 in the rotation axis direction AD.

[0079] In addition, the portions protruding from the upper end face 10a and the lower end face 10b of the stator core 10 in the rotation axis direction AD can also be bent toward the outside of the slot 11 in a manner that interferes with (is locked in) at least one side of the upper end side and the lower end side of the slot 11.

[0080] As described above, the slot liner 40 is arranged in the slot 11 so as to surround the four leg portions 21 b at least one circumference. Therefore, the slot liner 40 is arranged in the slot 11 so as to overlap with both ends in the circumferential direction.

[0081] That is, in the stator 1 of this embodiment, the overlapping portion 40a where the slot liners 40 overlap each other is formed in the slot 11 (see Figure 3 ).

[0082] Moreover, if Figure 3 As shown, in the stator 1 of this embodiment, the overlapping portion 40 a is located on the outside in the radial direction DD.

[0083] In the slot liner 40 of this embodiment, the insulating sheet 41 has a structure in which paper sheets 41c are laminated on both surfaces of a base sheet 41a via adhesive layers 41b, and the adhesive layer 42 is laminated on one side of the paper sheet 41c.

[0084] Since the slot liner 40 of the present embodiment needs to have a spring-back function in a folded state, it is necessary to have appropriate strength (rigidity).

[0085] Strength can be evaluated by the following procedure.

[0086] (1) The slot liner 40 having a planar size of 100 mm x 25 mm (length 100 mm x width 25 mm) is folded with the center in the longitudinal direction as a base point.

[0087] (2) The folded slot liner 40 is pressed at a pressure of 4 MPa for one second at room temperature using a hot press.

[0088] (3) After the pressurized slot liner 40 was left for three hours, the angle of the slot liner 40 when it was opened from the folded state was measured. Specifically, the angle between one side of the folded slot liner 40 and the other side was measured.

[0089] Furthermore, the fact that the slot liner 40 has appropriate strength means that the angle at which the slot liner 40 is opened from the folded state is 30° or more.

[0090] The strength of the slot liner 40 can be adjusted by appropriately selecting the type of material constituting the insulating sheet 41 and the thickness of the insulating sheet 41 .

[0091] In particular, in the slot liner 40 , as described above, when the insulating sheet body 41 includes the base sheet 41 a , the strength of the slot liner 40 is mainly affected by the strength of the base sheet 41 a .

[0092] Therefore, in such a case, when the base sheet 41 a is evaluated according to the above-mentioned procedure, it is preferable that the base sheet 41 a has a strength such that the angle at which the base sheet 41 a is opened from the folded state is 30° or more.

[0093] The strength of the base sheet 41 a can be adjusted by appropriately selecting the type of material constituting the base sheet 41 a and the thickness of the base sheet 41 a .

[0094] As the base sheet 41a, various known resin films can be used. For example, a film made of polyester resin (polyester-based resin film) can be used.

[0095] From the perspective of providing insulation reliability to the insulating sheet 41 and further from the perspective of providing insulation reliability to the slot liner 40, the base sheet 41a preferably has a volume resistivity of 1×10 12 Ω·cm or more (usually, 1×10 16 Ω·cm or less), preferably 1×10 13 Volume resistivity of Ω·cm or more.

[0096] The thickness of the base sheet 41a is usually 5 μm or more and 300 μm or less. The thickness of the base sheet 41a is preferably 25 μm or more and 125 μm or less.

[0097] The adhesive layer 41 b of the insulating sheet 41 is not particularly limited as long as it can adhere the base sheet 41 a and the paper-like sheet 41 c , and can be formed using a common pressure-sensitive adhesive or a reaction-curing adhesive.

[0098] Examples of the pressure-sensitive adhesive include rubber-based, acrylic-based, silicone-based, and polyurethane-based adhesives, and examples of the reaction-curing adhesive include acrylic-based, polyurethane-based, silicone-based, and epoxy-based adhesives.

[0099] The thickness of the adhesive layer 41b is usually 1 μm or more and 50 μm or less. The thickness of the adhesive layer 41b is preferably 5 μm or more and 10 μm or less.

[0100] As the paper-like sheet 41 c , a fiber nonwoven fabric such as a fiber nonwoven fabric made of a polyester resin (hereinafter also referred to as “polyester resin nonwoven fabric”) or an aramid fiber nonwoven fabric can be used.

[0101] As the polyester resin nonwoven fabric, a nonwoven fabric obtained by forming a sheet of polyester resin fibers with a binder or a nonwoven fabric obtained by forming a sheet of polyester resin fibers by heat fusion or the like without using a binder can be used.

[0102] The thickness of the paper-like sheet 41 c is preferably 5 μm or more and 300 μm or less.

[0103] The adhesive layer 42 of the slot liner 40 of this embodiment includes a resin and a foaming agent. The foaming agent is preferably dispersed in the resin.

[0104] The adhesive layer 42 preferably contains 10% by mass or more of a foaming agent, more preferably 20% by mass or more of a foaming agent. By containing 10% by mass or more of a foaming agent, the adhesive layer 42 disposed on both outer sides of the folded slot liner 40 can sufficiently contact the inner walls of the coil 20 and the slot 11, respectively. By containing 20% by mass or more of a foaming agent, the adhesive layer 42 disposed on both outer sides of the folded slot liner 40 can further sufficiently contact the inner walls of the coil 20 and the slot 11, respectively.

[0105] The adhesive layer 42 preferably contains 50% by mass or less of a foaming agent, more preferably 40% by mass or less of a foaming agent. By containing 50% by mass or less of a foaming agent, voids formed in the adhesive layer 42 due to foaming of the foaming agent can be reduced, resulting in an adhesive layer 42 having sufficient adhesiveness. By containing 40% by mass or less of a foaming agent, voids formed in the adhesive layer 42 due to foaming of the foaming agent can be further reduced, resulting in an adhesive layer 42 having even more sufficient adhesiveness.

[0106] As the thermosetting resin, various known thermosetting resins can be used, for example, epoxy resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane resin, polyimide resin, silicone resin, cyanoacrylate resin, modified acrylic resin, diallyl phthalate resin, etc.

[0107] The adhesive layer 42 may contain, in addition to the resin and the foaming agent, a diluent (organic solvent), a colorant, a filler (filler), a coupling agent, a defoaming agent, and a flame retardant, etc. In the case where the resin is a thermosetting resin, it may also contain a curing agent, a curing accelerator, etc.

[0108] As the foaming agent, a foaming agent in which a heat-expanding component is microencapsulated, sodium carbonate, calcium carbonate, ammonium carbonate, sodium hydrogen carbonate, aluminum carbonate, diazoaminobenzene, N,N′-dinitrosopentamethylenetetramine, or the like can be used.

[0109] When adhesive layer 42 contains a thermosetting resin, it is preferable to use a foaming agent containing microencapsulated thermal expansion components that thermally expand at the curing temperature of the thermosetting resin. This allows the foaming agent to foam within the thermosetting resin during its curing process. Specifically, while the thermosetting resin foams, causing the adhesive layer 42 to expand in volume, the adhesive layer 42 simultaneously solidifies, thereby bonding it to the inner wall surface of slot 11 and the like.

[0110] A foaming agent in which the thermal expansion component is microencapsulated is referred to as a microsphere foaming agent. Such a microsphere foaming agent is composed of a thermal expansion component (solid, liquid, or gas) encapsulated within a polymer shell composed of a thermoplastic or thermosetting resin. In other words, the microsphere foaming agent comprises a hollow polymer shell and the thermal expansion component encapsulated within the polymer shell, wherein the hollow polymer shell has a micro-ordered average particle size.

[0111] The resin constituting the polymer shell may be an acrylonitrile copolymer as a thermoplastic resin, and the thermal expansion component may be a hydrocarbon having a relatively low boiling point. Examples of such hydrocarbons include butane, pentane, and n-hexane.

[0112] Here, the microsphere foaming agent expands its volume by more than 40 times when heated, and can produce a foam in the form of closed cells. Therefore, even among various foaming agents, the microsphere foam has the characteristic of being able to intentionally increase the expansion ratio.

[0113] Therefore, when adhesive layer 42 includes microsphere foam, the content can be reduced (e.g., 10% to 30% by mass), thereby further reducing voids in adhesive layer 42 caused by the foaming agent. As a result, a decrease in the bulk strength of adhesive layer 42 can be suppressed, allowing the coil 20 to be adequately bonded to one side of adhesive layer 42, while the inner wall surface of slot 11 (i.e., the core) can be adequately bonded to the other side of adhesive layer 42.

[0114] In the slot liner 40 of this embodiment, as an example, the first region R1 and the second region R2 of the adjacent stacked sheets are folded along a fold line L1 to form an overlapping portion O1 of a two-layer structure, but the example of forming an overlapping portion on the slot liner 40 is not limited to this.

[0115] Therefore, below, refer to Figure 6 and Figure 7 Another example of forming the overlapping portion in the slot liner 40 of the present embodiment will be described.

[0116] First, the edge reference Figure 6 , another example of forming the overlapping portion on the slot liner 40 according to this embodiment will be described.

[0117] In this example, if Figure 6 As shown in (a) and (b) of FIG. 4 , the second region R2 adjacent to the first region R1 is bent toward the first region R1 via the first fold line L2 along two fold lines, namely, the first fold line L2 and the second fold line L3. The first region R1 constitutes the portion from the first fold line L2 to the second fold line L3. The third region R3 adjacent to the first region R1 is bent via the second fold line L3. The second region R2 and the third region R3 are folded toward the first region R1, respectively, to form a first overlapping portion O2 and a second overlapping portion O3. That is, the slot liner 40 is folded so as to have two overlapping portions of a two-layer structure.

[0118] The slot liner 40 thus folded is Figure 6 Clamping is performed as shown in (c).

[0119] That is, Figure 6 As shown in (c), the folded slot liner 40 is placed in a cylindrical shape within the slot 11, with the two overlapping portions (the first overlapping portion O2 and the second overlapping portion O3) facing inward. The four legs 21b are then inserted into the cylindrical slot liner 40. Thus, with the four legs 21b bundled together by the first overlapping portion O2 and the second overlapping portion O3, the slot liner 40 is sandwiched between the inner wall of the slot 11 and the four legs 21b before forming the coils.

[0120] In the slot liner 40 of the present embodiment, two overlapping portions of the two-layer structure are formed as described above. Even in this case, the respective springback functions generated in the two overlapping portions of the two-layer structure can be utilized.

[0121] Below, refer to Figure 7 , another example of forming the overlapping portion in the slot liner 40 of this embodiment will be described.

[0122] In this example, if Figure 7 As shown in (a) and (b) of FIG, the second region R2 adjacent to the first region R1 is bent along two fold lines, namely, the first fold line L2 and the second fold line L3, toward the first region R1 via the first fold line L2, thereby folding the second region R2 into the first region R1. The first region R1 constitutes the portion from the first fold line L2 to the second fold line L3. Next, the third region R3 adjacent to the first region R1 is bent along the second fold line L3, thereby folding the third region R3 into the second region R2, thereby forming a three-layer overlapping portion O4 in which the first to third regions R1 to R3 overlap. In other words, the slot liner 40 is folded so as to have a three-layer overlapping portion O4.

[0123] The folded slot liner 40 is as follows Figure 7 (c) is shown as being clamped.

[0124] That is, Figure 7 As shown in (c), the folded slot liner 40 is placed in a cylindrical state within the slot 11. Then, the four legs 21b are inserted into the cylindrical slot liner 40. Thus, the slot liner 40 is sandwiched between the inner wall of the slot 11 and the four legs 21b before coil formation, with the four legs 21b bundled together at once by a single three-layered overlapping portion O4.

[0125] Even if a single overlapping portion O4 having a three-layer structure is formed in the slot liner 40 of the present embodiment, the springback function generated in the single overlapping portion O4 having a three-layer structure can be utilized.

[0126] The slot liner of this embodiment is configured as described above, and therefore has the following advantages.

[0127] That is, the slot liner of this embodiment,

[0128] It is composed of a laminated sheet with an adhesive layer laminated on the surface of an insulating sheet.

[0129] The slot liner is used to be interposed between the inner wall surface of a slot provided in the stator core of a rotating electrical machine and the coil accommodated in the slot.

[0130] The slot liner has an overlapping portion, wherein the laminated sheet is folded to form a fold line, and the overlapping portion is formed by overlapping the first region and the second region of the adjacent laminated sheet via the fold line, and the overlapping portion is configured to be sandwiched between the inner wall surface of the slot and the coil.

[0131] The adhesive layer is disposed on one side surface that contacts the inner wall surface of the slot and the other side surface that contacts the coil.

[0132] According to this structure, the laminated sheet is sandwiched between the inner wall of the slot and the coil in a folded state. Therefore, a force (a force in the opposite direction of the folding direction) is generated in the slot to restore the laminated sheet to its pre-folded state. In other words, a spring-back function is generated in the folded laminated sheet.

[0133] Therefore, the laminated sheet in the folded state will expand in the direction opposite to the folding direction due to the rebound function. Therefore, even if the adhesive layer does not contain a foaming agent, the side surface that expands in the direction opposite to the folding direction can be brought into contact with the inner wall surface of the slot (i.e., the iron core), and the other side surface can be brought into contact with the coil.

[0134] Furthermore, when the adhesive layer does not contain a foaming agent, since it is not necessary to foam the adhesive layer, a decrease in bulk strength can be suppressed, thereby suppressing a decrease in the adhesive force of the adhesive layer.

[0135] In addition, in the slot liner of this embodiment,

[0136] It is preferable that the fold line is arranged toward the outside of the slot.

[0137] According to this configuration, when the slot liner is arranged in a cylindrical shape in the slot, when the coil is inserted into the slot, interference between the portion of the slot liner expanded by the rebound function and the coil, which would make insertion of the coil difficult, can be suppressed.

[0138] In addition, the slot liner of this embodiment is preferably:

[0139] In a state before being folded, the slot liner has a length that protrudes outward from both ends of the slot when being sandwiched between the inner wall surface of the slot and the coil.

[0140] A first fold line is provided on one end edge side of the slot, and a second fold line is provided on the other end edge side of the slot.

[0141] The first region extending from the first fold line to the second fold line, the second region adjacent to the first region via the first fold line, and the third region adjacent to the first region via the second fold line are provided.

[0142] Furthermore, there are a first overlapping portion formed by overlapping the first region and the second region, and a second overlapping portion formed by overlapping the first region and the third region.

[0143] According to this configuration, the first overlapping portion formed by overlapping the first region and the second region, and the second overlapping portion formed by overlapping the first region and the third region are located closer to the center of the laminate sheet in the folded state.

[0144] Typically, in a portion folded along a fold line, the further away from the fold line the folded portion is from the fold line, the greater the degree of folding. Therefore, as described above, the first overlapping portion and the second overlapping portion are located closer to the center of the folded laminate. In this case, at a closer center of the laminate, one side surface of the laminate can more fully abut and adhere to the inner wall surface of the slot liner, and the other side surface of the laminate can more fully abut and adhere to the coil. In other words, at a closer center position within the slot, the coil can be more fully secured within the slot.

[0145] In addition, the slot liner of this embodiment is preferably:

[0146] In the state before folding, the slot liner has a length that protrudes outward from both ends of the slot when it is sandwiched between the inner wall surface of the slot and the coil.

[0147] A first fold line is provided on one end edge side of the slot, and a second fold line is provided on the other end edge side of the slot.

[0148] The first region extending from the first fold line to the second fold line, the second region adjacent to the first region via the first fold line, and the third region adjacent to the first region via the second fold line are provided.

[0149] The overlapping portion has a three-layer structure in which the first region to the third region overlap.

[0150] According to this structure, the overlapping portion of the three-layer structure can be formed by the portion where the second region is folded toward the first region along the first fold line and the portion where the third region is folded toward the first region along the second fold line, that is, by two folded portions. Therefore, the springback function generated in each of the two folded portions can be utilized in the overlapping portion of the three-layer structure. As a result, the springback function can be more fully generated.

[0151] In addition, in the slot liner of this embodiment, preferably,

[0152] An adhesive layer is laminated only on one surface of the insulating sheet.

[0153] According to this configuration, when the laminated sheet is folded along the folding line, the portion where the adhesive layer sticks can be reduced compared to a case where the adhesive layer is laminated on both surfaces of the insulating sheet.

[0154] Thereby, the rebound function can be more fully exerted.

[0155] Furthermore, when stored in a rolled state, the surface on which the adhesive layer is not formed can be placed on the inner side. Therefore, when used, the roll can be easily pulled out to a length required for use from the rolled state.

[0156] In addition, in the slot liner of this embodiment, preferably,

[0157] The adhesive layer contains a resin and a foaming agent dispersed in the resin.

[0158] According to this configuration, the adhesive layer can be foamed by the foaming agent dispersed and contained in the adhesive layer. Therefore, the thickness of the adhesive layer can be made thinner than that of an adhesive layer not containing the foaming agent.

[0159] Furthermore, since the laminated sheet expands in the direction opposite to the folding direction due to its rebound function when folded, the amount of foaming agent contained in the adhesive can be reduced. Therefore, even when a foaming agent is contained, a decrease in the bulk strength of the adhesive layer can be suppressed, and as a result, a decrease in the adhesive strength of the adhesive layer can be suppressed.

[0160] The slot liner of the present invention is not limited to the above-described embodiment. Furthermore, the slot liner of the present invention is not limited to the above-described effects. Various modifications can be made to the slot liner of the present invention without departing from the spirit of the present invention.

[0161] For example, in the above embodiment, an example is described in which the adhesive layer 42 is formed only on one side of the insulating sheet 41, but in addition to one side of the insulating sheet 41, the adhesive layer 42 can also be formed on the other side (i.e., both sides of the insulating sheet 41).

[0162] Furthermore, in the above embodiment, an example in which the adhesive layer 42 contains a foaming agent is described. However, the adhesive layer 42 may not contain a foaming agent. Even in the case where the adhesive layer 42 does not contain a foaming agent, the rebound function generated by folding the slot liner 40 allows the adhesive layer 42 disposed on both outer sides of the folded slot liner 40 to contact and bond with the inner wall surfaces of the coil 20 and the slot 11, respectively.

[0163] In addition, in the above embodiment, the insulating sheet 41 is configured as follows. Figure 4 As shown, the insulating sheet 41 is described as having a five-layer structure in which paper sheets 41c are laminated on both sides of the base sheet 41a via adhesive layers 41b. However, the insulating sheet 41 is not limited to this example.

[0164] For example, the insulating sheet 41 may be constructed with a three-layer structure in which paper sheets are laminated on both sides of the adhesive layer, or it may be constructed with a single-layer structure consisting only of the paper sheet 41c. In such a case, when evaluating the three-layer insulating sheet 41 and the single-layer insulating sheet 41 according to the above procedure, it is preferred that the folded insulating sheet 41 have a strength such that the angle of expansion from the folded state is 30° or greater.

[0165] Furthermore, various known resin films used for the base sheet 41a may be formed by uniaxial stretching or biaxial stretching. In the case of a uniaxially stretched resin film, the slot liner 40 is preferably folded in a direction intersecting the uniaxial stretching direction of the base sheet 41a and accommodated in the slot 11. In other words, the slot liner 40 preferably has a fold line intersecting the uniaxial stretching direction of the base sheet 41a and is accommodated in the slot 11.

[0166] In the above embodiment, for example, Figure 5 As shown in (c), an example is described in which the folded slot liner 40 is accommodated in the slot 11 in such a manner that the fold line L1 faces the outside of the slot 11, but the position of the fold line L1 when accommodated in the slot 11 does not need to face the outside.

[0167] What is important is that, as long as the folding line L1 is in a state where the spring-back function can be generated, the folded slot liner 40 can be accommodated in the slot 11 .

Claims

1. A slot liner comprising a laminated sheet having an adhesive layer laminated on the surface of an insulating sheet. The slot liner is used to be sandwiched between the inner wall surface of the slot provided in the stator core of the rotating electrical machine and the coil accommodated in the slot. The laminate is folded to form a fold line, The slot liner has a first fold line on one end edge side of the slot and a second fold line on the other end edge side of the slot. The slot liner includes a first region extending from the first fold line to the second fold line, a second region adjacent to the first region via the first fold line, and a third region adjacent to the first region via the second fold line. The slot liner has an overlapping portion of a three-layer structure in which the first region to the third region overlap, The slot liner is arranged so that the overlapping portion is sandwiched between the inner wall surface of the slot and the coil. The slot liner has the adhesive layer disposed on one side surface that contacts the inner wall surface of the slot and the other side surface that contacts the coil. 2 . The slot liner according to claim 1 , wherein in a state before being folded, the slot liner has a length such that the slot liner protrudes outward from both ends of the slot when the slot liner is sandwiched between the inner wall surface of the slot and the coil. 3 . The slot liner according to claim 1 , wherein an adhesive layer is laminated only on one surface of the insulating sheet. The slot liner according to claim 1 or 2, wherein the adhesive layer comprises a resin and a foaming agent dispersed in the resin.

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