Stator and motor

Abstract

A stator is a stator of an inner rotor motor, having: a stator core portion of an annular shape having a cutout recessed from a radially inner side toward a radially outer side; a coil having a wire disposed inside the cutout; a first insulating member of a sheet shape disposed between the wire and the stator core portion; a second insulating member of a sheet shape at least a part of which is disposed radially inward of the first insulating member inside the cutout; and an impregnating agent impregnated at least between the stator core portion and the second insulating member and between the second insulating member and the wire. At least a part of the second insulating member has a plurality of layers stacked in a radial direction. A layer radially innermost among the plurality of layers is a resin layer. At least a part of the resin layer is exposed toward the radially inner side via the cutout.

Description

Technical Field

[0001] This invention relates to a stator and a motor. Background Technology

[0002] Conventionally, it is known that stators installed in motors of electric vehicles, hybrid vehicles, etc., are provided with the following configuration: The stator has a stator core comprising pole teeth arranged circumferentially. Slots are provided between adjacent pole teeth. Coil wires are arranged within the slots, and insulating paper for insulating the wires and the stator core is provided. Furthermore, varnish is impregnated onto the coils and the insulating paper, thereby insulating the coils from the stator core while simultaneously fixing the coils and the insulating paper to the stator core (for example, see Patent Document 1).

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2015-35920 Summary of the Invention

[0004] The technical problem that the invention aims to solve However, in conventional stators, during the varnish impregnation process, the varnish adheres to areas other than the desired locations on the insulating paper, requiring a process to remove the adhered varnish. Therefore, there is room to improve the stator's productivity by enhancing the workability of this process.

[0005] The purpose of this disclosure is to provide a stator that can improve productivity.

[0006] Technical solutions adopted to solve technical problems The exemplary stator of this disclosure is a stator for an internal rotor motor, comprising: an annular stator core having a groove recessed from a radially inward to a radially outward direction; a coil having a conductor disposed within the groove; a sheet-like first insulating member disposed between the conductor and the stator core; a sheet-like second insulating member, at least a portion of which is disposed radially inward within the groove compared to the first insulating member; and an impregnating agent impregnating at least between the stator core and the second insulating member and between the second insulating member and the conductor. At least a portion of the second insulating member has a plurality of layers stacked radially. The innermost layer of the plurality of layers is a resin layer. At least a portion of the resin layer is exposed radially inward through the groove.

[0007] Invention Effects The exemplary stator according to this disclosure can improve productivity. Attached Figure Description

[0008] Figure 1This is a cross-sectional view of the electric drive device according to the embodiment. Figure 2 This is a three-dimensional view of one end of the stator along its axial direction. Figure 3 This is a three-dimensional view of the stator core. Figure 4 This is a partially enlarged view showing the structure around the groove of the stator. Figure 5 This is a flowchart used to illustrate an example of a stator manufacturing method. Figure 6 This is an example of a coil formed during the stator manufacturing process. Figure 7 This is a partial sectional view of the stator. Figure 8 This diagram shows the groove when viewed from the radial inside to the radial outside. Figure 9 The diagram shows the unfolded second insulating member viewed from the radial inside to the radial outside (upper section) and a cross-sectional view of the second insulating member (I-I section) (lower section). Figure 10 This is a cross-sectional view I-I showing a modified example of the layer structure of the second insulating member. Figure 11 The figure shows the second insulating member of the first modified example after being viewed from the radial inside to the radial outside (upper section) and a cross-sectional view of the second insulating member along line I-I (lower section). Figure 12 This is a diagram of the second insulating member in the second modified example, viewed from the radial inside to the radial outside after unfolding. Figure 13 This is a diagram of the second insulating member in the third modified example, viewed from the radial inside to the radial outside after unfolding. Figure 14 This is a diagram of the second insulating member in the fourth modified example, viewed from the radial inside to the radial outside after unfolding. Figure 15 This is a diagram of the second insulating member in the fifth modified example, viewed from the radial inside to the radial outside after unfolding. (Symbol Explanation) 11 rotors 12 stators 100 motors 110 axis 111 rotor core 112 magnets 121 stator core 122 coil 122A wire 123 alternating paper 124 bundled components 125 First Insulating Component 126 Second Insulating Component 127 Impregnating Agent 200 speed reduction device 400 casing 700 electric drive unit 1211 core back 1212 pole teeth 1221 coil terminal 1222 Straight Section 1261 aramid layer 1262 resin layer 1262A and 1262B resin layers 1263 and 1264 adhesive layers CA central axis S-groove SA radial inner end. Detailed Implementation

[0009] Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings.

[0010] In addition, in this specification, in the electric drive device 700, the direction parallel to the central axis CA of the motor 100 is referred to as the "axial direction". The direction from the second axis 110b toward the first axis 110a is referred to as the "axial side", and the direction from the first axis 110a toward the second axis 110b is referred to as the "axial side".

[0011] Furthermore, the direction orthogonal to the central axis CA is called "radial," and the direction of rotation centered on the central axis CA is called "circumferential." The direction in the radial direction closest to the central axis CA is called "radial inner," and the direction away from the central axis CA is called "radial outer."

[0012] Furthermore, in this specification, "ring-shaped" includes not only shapes that are continuously connected in one piece without slits throughout the entire circumference centered on the central axis CA, but also shapes that have slits in a portion of the entire circumference centered on the central axis CA.

[0013] <1. Structure of the electric drive unit> The electric drive unit 700 of the embodiment is installed in vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHV), and electric vehicles (EV) that use motor 100 as a drive source, and is used as a drive source to drive the vehicle and make it rotate. Figure 1 This is a cross-sectional view of the electric drive device 700 according to the embodiment. Additionally, Figure 1The cross-sectional structure of the electric drive unit 700 is shown when the plane including the central axis CA of the motor 100 is cut off.

[0014] like Figure 1 As shown, the electric drive unit 700 includes a motor 100, a reduction gear 200, a differential (not shown), and a housing 400. The housing 400 includes: a motor housing 401 for housing the motor 100; a reduction gear housing 402 for housing the reduction gear 200; and a differential housing (not shown) for housing the differential. The motor 100 is driven by three-phase AC. The reduction gear 200 is connected to the motor 100, increasing the torque transmitted from the motor 100 at a predetermined reduction ratio and transmitting it to the differential. The differential is connected to the motor 100 via the reduction gear 200, transmitting the torque transmitted from the reduction gear 200 to the wheels.

[0015] <2. Motor Structure> like Figure 1 As shown, the motor 100 includes a rotor 11 and a stator 12.

[0016] The rotor 11 is arranged radially inward of the stator 12 and can rotate circumferentially around the central axis CA. That is, the motor 100 is an internal rotor type motor, having a stator 12 and a rotor 11 arranged radially inward of the stator 12. The stator 12 is an internal rotor type stator. The rotor 11 has a shaft 110, a rotor core 111, and a magnet 112.

[0017] Shaft 110 is the shaft of rotor 11. Shaft 110 is supported by motor housing 401 via bearings (notation omitted) and is rotatable. Shaft 110 has a first shaft 110a, a second shaft 110b, and a first gear portion 110c. The first shaft 110a and the second shaft 110b are hollow cylindrical sections extending axially. One axial end of the second shaft 110b is connected to the other axial end of the first shaft 110a. The first gear portion 110c is a gear that meshes with the second gear portion 210 of the reduction gear 200, transmitting the driving force of motor 100 to the reduction gear 200. The first gear portion 110c is provided on the radially outer side of the second shaft 110b. The second shaft 110b protrudes from motor housing 401 in the other axial direction. Therefore, the other axial portion of the second shaft 110b and the first gear portion 110c are housed within the reduction housing 402.

[0018] The rotor core 111 is a ring-shaped magnetic body centered on the central axis CA. In this embodiment, it is a stack of multiple plate-shaped electromagnetic steel plates. The rotor core 111 is fixed to the radially outer side of the first shaft 110a. The rotor core 111 has multiple through holes 1111 extending through it axially. The through holes 1111 are arranged at intervals in the circumferential direction.

[0019] Magnet 112 has multiple magnetic plates (not shown). Each magnetic plate is a flat plate extending in a direction orthogonal to the radial direction and is held within a through hole 1111 of rotor core 111. In other words, the magnetic plates are arranged at intervals in the circumferential direction.

[0020] The stator 12 drives the rotor 11 to rotate. The stator 12 is in the shape of a ring with the central axis CA as the center. Figure 2 This is a three-dimensional view of one end of the stator 12 along its axial direction.

[0021] The stator 12 has a stator core 121, a coil 122, a phase paper 123, a binding member 124, and a first insulating member 125 (described below). Figure 4 (as shown in the diagram) and the second insulating member 126 (as described below) Figure 4 (See diagram in the middle).

[0022] Figure 3 This is a perspective view of the stator core 121. The stator core 121 is a ring-shaped magnetic body centered on the central axis CA. In this embodiment, it is a stack of multiple plate-shaped electromagnetic steel plates. Figure 3 As shown, the stator core 121 has an annular core back 1211, multiple pole teeth 1212 and multiple grooves S.

[0023] Multiple pole teeth 1212 extend radially inward from the radially inner end of the core back 1211 and are arranged circumferentially. A groove S is provided between circumferentially adjacent pole teeth 1212. Multiple grooves S are provided at the radially inner end of the annular stator core 121 and are arranged circumferentially. The groove S is a space recessed radially outward from the radially inner end face of the stator core 121 and extends axially. The groove S opens radially inward. That is, the stator 12 has an annular stator core 121, and the stator core 121 has grooves S recessed radially inward from the radially inner side to the radially outer side.

[0024] Figure 4 This is a partially enlarged view showing the structure around the groove S of the stator 12. Figure 4 The structure at one end of the axial side of the stator core 121 is shown in a schematic diagram.

[0025] The stator 12 has a coil 122A disposed inside the slot S. That is, the stator 12 has a coil 122, which has a conductor 122A disposed inside the slot S. A first insulating member 125 formed of insulating material is disposed inside the slot S. The first insulating member 125 is an axially extending sheet member, also called slotting paper, which is bent and housed inside the slot S in a radially outwardly projecting manner. The two axial ends of the first insulating member 125 protrude axially outwardly from the stator core 121. The first insulating member 125 surrounds the conductor 122A from the radially outwardly and circumferentially sides, providing insulation between the conductor 122A and the stator core 121. That is, the stator 12 has a sheet-like first insulating member 125 disposed between the conductor 122A and the stator core 121.

[0026] A second insulating member 126, also known as wedge paper, is disposed inside the slot S. The second insulating member 126 is an axially extending sheet-like member, bent and housed within the slot S in a radially inwardly projecting manner. Both axial ends of the second insulating member 126 protrude axially outward from the stator core 121. The two ends of the second insulating member 126, protruding radially inward from its top, overlap a portion of the first insulating member 125. The portion of the second insulating member 126, excluding the aforementioned ends, is disposed radially inwardly than the first insulating member 125. The second insulating member 126 surrounds the conductor 122A from both radially inwardly and circumferentially, providing insulation between the conductor 122A and the stator core 121. In other words, the stator 12 has at least a portion of a sheet-like second insulating member 126 disposed radially inwardly than the first insulating member 125 within the slot S. Furthermore, the second insulating member 126 will be described in more detail below.

[0027] Each coil 122 is arranged across different slots S. In this embodiment, multiple coils 122 are individually overlapped in a distributed winding manner. More specifically, each coil 122 is any one of a U-phase coil, a V-phase coil, or a W-phase coil. Each phase coil 122 is Y-connected in this embodiment. Coils 122 of the same phase are electrically connected via a connection wire or busbar (not shown). Coils 122 of the same phase are housed in slots S that are separated from each other by a distributed winding manner across multiple slots S that house the coils 122 of the other two phases. Furthermore, coils 122 of the same phase are housed in each slot S by single-layer overlap winding. In other words, coils 122 of different phases are not housed in the same slot S.

[0028] Furthermore, in this embodiment, the conductor 122A of the coil 122 is a circular wire with a circular cross-sectional shape. However, it is not limited to the above example; conductors 122A with a cross-sectional shape other than a circle may also be used. For example, the cross-sectional shape of the conductor may also be a polygonal shape such as a rectangle or a hexagon.

[0029] Each coil 122 has a coil end 1221. The coil end 1221 is the portion of the coil 122 that protrudes outward from the slot S, and is located on one side of the stator core 121 and on the other side of the stator core 121.

[0030] The interleaving paper 123 is configured to provide electrical insulation between different coils 122, for example, by having non-woven paper pasted on both sides of a sheet-like thin resin board.

[0031] The binding member 124 is in the form of an insulated rope, which binds the wire 122A of the coil end 1221.

[0032] <3. Stator Manufacturing Method> Next, the manufacturing method of stator 12 will be explained. Figure 5 This is a flowchart used to illustrate an example of the manufacturing method of stator 12.

[0033] First, the coil 122 is formed by winding the wire into a clamp with its long side facing outwards to create a coil shape (S1). In this embodiment, half the total number of coils 122 with cuts S are formed. For example, as... Figure 6 As shown, the coil 122 is shaped as follows: coil ends 1221 having two ends in the long side direction and a pair of straight portions 1222 extending along the long side direction. Furthermore, the pair of straight portions 1222 have a first straight portion 1222a and a second straight portion 1222b. At this time, as... Figure 6 As shown, in this embodiment, the coil shape of each coil 122 perpendicular to the extension direction dL is formed into a hexagonal shape with the long side direction. However, the coil shape is not limited to the example shown above; for example, it may also be an elliptical shape with the long side direction.

[0034] Next, the first insulating member 125 is installed on the stator core 121 (S2). At this time, the first insulating member 125 is inserted into the slot S. Here, Figure 4 This shows the state after the first insulating member 125 is inserted into the groove S. For example... Figure 4 As shown, the first insulating member 125 extends axially and has a shape that bends along the inner wall of the groove S and opens radially inward. Furthermore, the first insulating member 125 protrudes from the groove S on both the axial side and the other axial side.

[0035] Next, two in-phase coils 122 are sequentially installed on the stator core 121 (S3). First, the straight portions 1222 of each of the two in-phase coils 122 are respectively positioned radially inward from the slot S that houses the straight portion 1222 at the same circumferential position as the slot S. At this time, each straight portion 1222 is arranged to be housed in its corresponding slot S. Then, each straight portion 1222 is pressed radially outward to insert into its corresponding slot S. Thus, the coils 122 are arranged spanning different slots S.

[0036] After all the coils 122 are installed in the stator core 121, the second insulating member (wedge paper) 126 is inserted into each slot S (S4). Figure 4 As shown, the second insulating member 126 extends axially and has a shape that bends along the inner wall of the groove S and opens radially outward. Furthermore, the second insulating member 126 protrudes from the groove S on both the axial side and the other axial side.

[0037] Next, the phase paper 123 is sandwiched between the coil ends 1221 of the coils 122 of adjacent phases in the circumferential direction (S5).

[0038] Next, the coil end 1221, where the interleaving paper 123 is disposed between different coil ends 1221, is pressed along the axial direction (S6). That is, the coil end 1221 on one side of the stator 12 along with one side of the interleaving paper 123 is pressed towards the other side of the axial direction, forming a shape with a lower axial height. Furthermore, the coil end 1221 on the other side of the stator 12 along with the other side of the interleaving paper 123 is pressed towards one side of the axial direction, forming a shape with a lower axial height.

[0039] Next, in order to prevent the wire 122A of the coil end 1221 from becoming tangled, the coil end 1221 and the photo paper 123 that have been pressed are bundled together using the binding member 124 (S7).

[0040] Next, using clamps, an impregnating agent is injected into the coil ends 1221 on both the axial side and the axial side (S8). For example, a varnish can be used as the impregnating agent. For example, WP-2820(GN) (manufactured by Showa Denko Materials Co., Ltd. (formerly Hitachi Chemical Co., Ltd.)) can be used as the varnish. Furthermore, the impregnating agent is injected while rotating the stator core 121 around the central axis CA. The injected impregnating agent impregnates to the axial center of the stator core 121 due to capillary action. The impregnating agent cures after impregnation.

[0041] <4. Insulating Components> Next, the structure of the second insulating member (wedge-shaped paper) 126 will be described in detail. Furthermore, in the following figures, the inner radial side is denoted as R1, the outer radial side as R2, one axial side as Z1, the other axial side as Z2, and the circumferential direction as θ.

[0042] Figure 7 This is a partial sectional view of the stator 12, taken at the midpoint of the axial direction and cut with a plane perpendicular to the axial direction. Additionally, in Figure 7 For convenience, a portion of the conductor 122A and the first insulating member 125 disposed inside the slot S are omitted from the illustration.

[0043] like Figure 7 As shown, the second insulating member 126 is a two-layer structure consisting of an aramid layer 1261 and a resin layer 1262. The second insulating member 126 is disposed inside the groove S, bent along the inner wall of the groove S with the aramid layer 1261 side facing outwards. That is, the second insulating member 126 has at least a portion of multiple layers 1261 and 1262 stacked radially, and the innermost layer among these multiple layers is the resin layer 1262.

[0044] The aramid layer 1261 is manufactured using a process such as a papermaking machine. Neither the aramid layer 1261 nor the resin layer 1262 undergoes surface treatment. In its untreated state, the resin layer 1262 has a surface roughness that makes it less susceptible to impregnation by the impregnating agent than the aramid layer 1261. Specific examples of the materials used in the aramid layer 1261 and the resin layer 1262 are described below.

[0045] In addition, such as Figure 7 As shown, through the above-described impregnating agent coating process, the impregnating agent 127 is impregnated between the pole teeth 1212 and the second insulating member 126, and between the second insulating member 126 and the conductor 122A. That is, the stator 12 has an impregnating agent 127 impregnated at least between the stator core 121 and the second insulating member 126, and between the second insulating member 126 and the conductor 122A.

[0046] Figure 8 This diagram shows the groove S as viewed from the radial inside to the radial outside. (Example) Figure 7 and Figure 8 As shown, a portion 1262P of the resin layer 1262 is exposed radially inward through the radially inner end portion SA included in the groove S. That is, at least a portion of the resin layer 1262 is exposed radially inward through the groove S.

[0047] Therefore, the resin layer 1262, which has a surface roughness that makes it difficult for impregnating agent to adhere, is set as the innermost layer in the second insulating member 126, and at least a portion of the resin layer 1262 is exposed radially inward via the groove S. Thus, in the impregnating agent coating process after the installation process of the second insulating member 126, the adhesion of the impregnating agent to the exposed portion (1262P) in the second insulating member 126 is suppressed. Considering the contact between the impregnating agent and the rotor 11, a process is implemented to remove the impregnating agent adhering to the exposed portion in the resin layer 1262. However, due to the suppression of impregnating agent adhesion and the surface roughness of the resin layer 1262 that makes it difficult for the impregnating agent to adhere, the impregnating agent removal operation becomes easy to perform. Therefore, the productivity of the stator 12 can be improved. Thus, the productivity of the motor 100 having the stator 12 can be improved.

[0048] Furthermore, assuming the second insulating member 126 is disposed within the groove S with the resin layer 1262 positioned radially outward and the aramid layer 1261 positioned radially inward, a portion of the aramid layer 1261 is exposed radially inward from the groove S. The impregnating agent readily adheres to the aramid layer 1261, thus easily adhering to the exposed portion. Consequently, due to the increased amount of impregnating agent adhering to the exposed portion and the surface roughness of the exposed portion facilitating impregnating agent adhesion, the impregnating agent removal operation becomes difficult. Therefore, there is a possibility of decreased productivity of the stator 12. Moreover, since the resin layer 1262 is positioned radially outward, it is difficult for the impregnating agent to impregnate between the second insulating member 126 and the conductor 122A, where the impregnating agent is desired to adhere.

[0049] Figure 9 The diagram shows the second insulating member 126 as viewed from the radial inside to the radial outside, with the resin layer 1262 facing the radial inside. (Upper section) and the diagram also show a cross-sectional view of the second insulating member 126 along line I-I. (Lower section).

[0050] Figure 9 The I-I sectional view shown illustrates a specific example of the two-layer structure of the second insulating member 126. Figure 9 In the two-layer structure shown, resin layer 1262 includes resin layer 1262A and resin layer 1262B. Resin layer 1262A and resin layer 1262B are bonded by an adhesive-based bonding layer 1263. Aramid layer 1261 and resin layer 1262A are bonded by adhesive layer 1264. Resin layer 1262A and resin layer 1262B are formed of the same material, but are formed of a resin different from that of aramid layer 1261. In this specification, when multiple layers formed of the same material, such as resin layers 1262A and 1262B, are bonded by an adhesive, these multiple layers are considered as one layer. Thus, Figure 9The second insulating member 126 shown is a two-layer structure based on an aramid layer 1261 and a resin layer 1262.

[0051] That is, as described above, the second insulating member 126 has at least a portion of a plurality of layers 1261, 1262 stacked radially. Figure 7 Furthermore, these multiple layers consist of an aramid layer 1261 and a resin layer 1262, which is different from the aramid layer 1261. This allows for both ensuring the strength and thinness of the second insulating member 126.

[0052] Preferably, the aramid layer 1261 is made of Nomex (a registered trademark), and the resin layer 1262 is made of PPS (polyphenylene sulfide). By using Nomex, which has excellent heat resistance and strength, for the aramid layer 1261, and PPS, which is less prone to impregnation by impregnating agents, the durability of the second insulating member 126 and the inhibition of impregnation by impregnating agent adhesion can be achieved.

[0053] For example, Torelina (a registered trademark) can be used as the aforementioned PPS. Furthermore, the resin layer 1262 is not limited to being composed of PPS, but can also be composed of PEI (polyetherimide), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), etc.

[0054] In addition, in manufacturing, where there are few restrictions on the thickness of a resin layer, such as Figure 10 As shown in the I-I cross-sectional view, the resin layer 1262 of the desired thickness can also be formed by a single resin layer.

[0055] Furthermore, the second insulating member 126 can also be a layered structure with three or more layers. Additionally, the layers of the second insulating member 126 can be directly bonded together without the use of adhesives or the like. By making the second insulating member 126 a multi-layered structure, the progression of cracking can be suppressed even if the surface of the second insulating member 126 is damaged. Furthermore, the adhesive layer formed by bonding the layers together improves oil resistance.

[0056] <5. First Variation> Next, a first modified example of the second insulating member 126 will be described. Figure 11 The figure shows the second insulating member 126 of the first modified example, viewed from the radial inside to the radial outside with the resin layer 1262 facing the radial inside. (Upper section) and the I-I sectional view of the second insulating member 126 are shown. (Lower section)

[0057] Figure 11In the unfolded state of the second insulating member 126 shown, the portion consisting of the resin layer 1262 and adhesive layers 1263 and 1264 protrudes radially inward from the circumferential center of the aramid layer 1261. The portion consisting of the resin layer 1262 and adhesive layers 1263 and 1264 is provided throughout the entire axial range of the aramid layer 1261. Alternatively, the aforementioned portion may be provided within a portion of the axial range of the aramid layer 1261.

[0058] That is, viewed from the radial inside to the radial outside. Figure 11 When the second insulating member 126 is in the unfolded state shown, at least a portion of the resin layer 1262 is disposed at the circumferential center of the second insulating member 126, and the aramid layer 1261 is disposed on both circumferential sides of the resin layer 1262 disposed at the circumferential center.

[0059] The portion of the second insulating member 126 exposed radially inward via the groove S is the portion where it is undesirable for impregnating agent to adhere. Therefore, in the circumferential direction, the resin layer 1262, where impregnating agent is not easily adhered, is confined to the circumferential center, and instead of resin layers 1262 on both circumferential sides, aramid layers 1261, where impregnating agent is easily adhered, are provided. This improves the impregnation rate of the impregnating agent.

[0060] <6. Second variation> Next, a second modified example of the second insulating member 126 will be described. Figure 12 This is a diagram of the second insulating member 126 in a second modified example, viewed from the radial inside to the radial outside, with the resin layer 1262 facing the radial inside.

[0061] Figure 12 In the unfolded state of the second insulating member 126 shown, the portion consisting of the resin layer 1262 and adhesive layers 1263 and 1264 protrudes radially inward from the axial center of the aramid layer 1261. The portion consisting of the resin layer 1262 and adhesive layers 1263 and 1264 is provided over the entire circumferential area of ​​the aramid layer 1261. Alternatively, the aforementioned portion may be provided only within a portion of the circumferential area of ​​the aramid layer 1261.

[0062] That is, viewed from the radial inside to the radial outside. Figure 12 When the second insulating member 126 is in the unfolded state shown, at least a portion of the resin layer 1262 is disposed at the axial center of the second insulating member 126, and the aramid layer 1261 is disposed on both sides of the resin layer 1262 disposed at the axial center.

[0063] The impregnating agent is injected from both axial sides of the stator 12 through a clamp and impregnates to the axial center of the stator 12 due to capillary action. The gap between the resin layer 1262 disposed at the axial center of the second insulating member 126 and the stator core 121 is narrower than the gap between the aramid layer 1261 disposed on both axial sides of the resin layer 1262 and the stator core 121. Therefore, the impregnating agent easily penetrates to the axial center due to capillary action. Thus, the impregnation rate or impregnation speed can be improved.

[0064] <7. Third variation> Next, a third variation of the second insulating member 126 will be described. Figure 13 This is a diagram of the second insulating member 126 in the third modified example, viewed from the radial inside to the radial outside, with the resin layer 1262 facing the radial inside.

[0065] Figure 13 In the unfolded state of the second insulating member 126 shown, the portion consisting of the resin layer 1262 and the adhesive layers 1263 and 1264 protrudes radially inward from one axial end and the other axial end of the aramid layer 1261, respectively.

[0066] That is, viewed from the radial inside to the radial outside. Figure 13 When the second insulating member 126 is in the unfolded state shown, at least a portion of the resin layer 1262 is disposed at both axial ends of the second insulating member 126, and the aramid layer 1261 is disposed axially between the resin layers 1262 disposed at both axial ends.

[0067] The impregnating agent is injected from both axial sides of the stator 12 and penetrates towards the axial center. By distributing the resin layer 1262 at both axial ends of the second insulating member 126, the gap between the second insulating member 126 and the stator core 121 at both axial ends can be narrowed, so that the impregnating agent does not stay at both axial ends and can easily penetrate towards the axial center.

[0068] <8. Fourth Variation> Next, a fourth variation of the second insulating member 126 will be described. Figure 14 This is a diagram of the second insulating member 126 in the fourth modified example, viewed from the radial inside to the radial outside, with the resin layer 1262 facing the radial inside.

[0069] Figure 14 In the unfolded state of the second insulating member 126 shown, the portion consisting of the resin layer 1262 and the adhesive layers 1263 and 1264 protrudes radially inward from the circumferential center and axial center of the aramid layer 1261, respectively. Thus, when viewed from the radially inward to the radially outward... Figure 14When the second insulating member 126 is in its unfolded state as shown, the axially extending resin layer 1262 and the circumferentially extending resin layer 1262 intersect at the center of the aramid layer 1261. According to the above-described fourth modification, the same effects as the first and second modifications can be achieved.

[0070] <9. Fifth Variation> Next, a fifth variation of the second insulating member 126 will be described. Figure 15 This is a diagram of the second insulating member 126 in the fifth modified example, viewed from the radial inside to the radial outside, with the resin layer 1262 facing the radial inside.

[0071] Figure 15 In the unfolded state of the second insulating member 126 shown, portions consisting of the resin layer 1262 and adhesive layers 1263 and 1264 protrude radially inward from the circumferential center, axial center, axial ends, and circumferential ends of the aramid layer 1261, respectively. Thus, it achieves the same effects as the first, second, and third modifications.

[0072] Furthermore, in the fifth variation, when viewed from the radially inner side towards the radially outer side... Figure 15 When the second insulating member 126 is in its unfolded state as shown, at least a portion of the resin layer 1262 is disposed at both circumferential ends of the second insulating member 126, and the aramid layer 1261 is disposed circumferentially between the resin layers 1262 disposed at both circumferential ends. Therefore, when the second insulating member 126 is installed to the stator core 121, even if the circumferential end of the second insulating member 126 contacts the stator core 121, it is the resin layer 1262, whose surface roughness is smoother than that of the aramid layer 1261, that contacts the stator core 121. Thus, the circumferential end of the second insulating member 126 can easily slide relative to the stator core 121. Therefore, it is easy to install the second insulating member 126 into the groove S.

[0073] <10. Others> The embodiments of this disclosure have been described above. However, the scope of this disclosure is not limited to the above embodiments. Various modifications can be made to and implemented with respect to the above embodiments without departing from the spirit of the invention. Furthermore, the items described in the above embodiments can be appropriately and arbitrarily combined without causing contradictions.

[0074] Industrial availability As an example, this disclosure can be used for vehicle motors, etc.

Claims

1. A stator, said stator being the stator of an internal rotor motor, characterized in that, have: An annular stator core having a groove recessed from the radially inner side to the radially outer side; A coil having a conductor disposed inside the groove; A sheet-like first insulating member is disposed between the conductor and the stator core; A sheet-like second insulating member, at least a portion of which is disposed radially inward within the groove compared to the first insulating member; as well as An impregnating agent is applied at least between the stator core and the second insulating member, and between the second insulating member and the conductor. At least a portion of the second insulating member has multiple layers stacked radially. The innermost layer in the radial direction among the plurality of layers is the resin layer. At least a portion of the resin layer is exposed radially inward through the groove. The plurality of layers consists of an aramid layer and a resin layer that is different from the aramid layer. When viewing the second insulating member unfolded with the resin layer facing radially inward from the radially inward side, At least a portion of the resin layer is disposed at the circumferential center of the second insulating member. The aramid layer is disposed on both sides of the resin layer disposed at the circumferential center.

2. The stator according to claim 1, characterized in that, The aramid layer is composed of meta-aramid fibers. The resin layer is composed of PPS, or polyphenylene sulfide.

3. A stator, said stator being the stator of an internal rotor motor, characterized in that, have: An annular stator core having a groove recessed from the radially inner side to the radially outer side; A coil having a conductor disposed inside the groove; A sheet-like first insulating member is disposed between the conductor and the stator core; A sheet-like second insulating member, at least a portion of which is disposed radially inward within the groove compared to the first insulating member; as well as An impregnating agent is applied at least between the stator core and the second insulating member, and between the second insulating member and the conductor. At least a portion of the second insulating member has multiple layers stacked radially. The innermost layer in the radial direction among the plurality of layers is the resin layer. At least a portion of the resin layer is exposed radially inward through the groove. The plurality of layers consists of an aramid layer and a resin layer that is different from the aramid layer. When viewing the second insulating member unfolded with the resin layer facing radially inward from the radially inward side, At least a portion of the resin layer is disposed at the axial center of the second insulating member. The aramid layer is disposed on both sides of the resin layer disposed at the axial center.

4. The stator according to claim 3, characterized in that, The aramid layer is composed of meta-aramid fibers. The resin layer is composed of PPS, or polyphenylene sulfide.

5. A stator, said stator being the stator of an internal rotor motor, characterized in that, have: An annular stator core having a groove recessed from the radially inner side to the radially outer side; A coil having a conductor disposed inside the groove; A sheet-like first insulating member is disposed between the conductor and the stator core; A sheet-like second insulating member, at least a portion of which is disposed radially inward within the groove compared to the first insulating member; as well as An impregnating agent is applied at least between the stator core and the second insulating member, and between the second insulating member and the conductor. At least a portion of the second insulating member has multiple layers stacked radially. The innermost layer in the radial direction among the plurality of layers is the resin layer. At least a portion of the resin layer is exposed radially inward through the groove. The plurality of layers consists of an aramid layer and a resin layer that is different from the aramid layer. When viewing the second insulating member unfolded with the resin layer facing radially inward from the radially inward side, At least a portion of the resin layer is disposed at both axial ends of the second insulating member. The aramid layer is disposed axially between the resin layers disposed at both ends of the axial direction.

6. The stator according to claim 5, characterized in that, The aramid layer is composed of meta-aramid fibers. The resin layer is composed of PPS, or polyphenylene sulfide.

7. A stator, said stator being the stator of an internal rotor motor, characterized in that, have: An annular stator core having a groove recessed from the radially inner side to the radially outer side; A coil having a conductor disposed inside the groove; A sheet-like first insulating member is disposed between the conductor and the stator core; A sheet-like second insulating member, at least a portion of which is disposed radially inward within the groove compared to the first insulating member; as well as An impregnating agent is applied at least between the stator core and the second insulating member, and between the second insulating member and the conductor. At least a portion of the second insulating member has multiple layers stacked radially. The innermost layer in the radial direction among the plurality of layers is the resin layer. At least a portion of the resin layer is exposed radially inward through the groove. The plurality of layers consists of an aramid layer and a resin layer that is different from the aramid layer. When viewing the second insulating member unfolded with the resin layer facing radially inward from the radially inward side, At least a portion of the resin layer is disposed at both circumferential ends of the second insulating member. The aramid layer is disposed circumferentially between the resin layers disposed at both ends of the circumferential direction.

8. The stator according to claim 7, characterized in that, The aramid layer is composed of meta-aramid fibers. The resin layer is composed of PPS, or polyphenylene sulfide.

9. A motor, characterized in that, have: The stator according to any one of claims 1 to 8; and The rotor is disposed radially inside the stator.

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