Rotor and IPM motor comprising the same

Abstract

Provided is a rotor and an IPM motor including the same. The rotor includes a cylindrical rotor core having a magnet insertion hole extending in an axial direction, a rotor magnet inserted into the magnet insertion hole, and a positioning member that positions the rotor magnet within the magnet insertion hole. The positioning member has a first foamed layer containing a bonding material that bonds with the rotor magnet, a second foamed layer that is in contact with an inner surface of the magnet insertion hole of the rotor core, and a base material layer between the first foamed layer and the second foamed layer, the first foamed layer, the second foamed layer, and the base material layer being in a stacked state between the rotor magnet and the inner surface of the magnet insertion hole.

Description

TECHNICAL FIELD

[0001] The present application relates to a rotor and an IPM motor including the same. BACKGROUND

[0002] A rotor for an IPM motor in which a rotor magnet is inserted into a magnet insertion hole extending in the axial direction of a rotor core is known. Further, a structure in which the rotor magnet is positioned in the magnet insertion hole in the above-described rotor is disclosed. For example, a rotor in which an adhesive sheet is interposed between a permanent magnet and a rotor core in a slit hole, and the adhesive sheet is expanded and cured, whereby the permanent magnet can be fixed in the slit hole is disclosed in Patent Literature 1.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2006-311782

[0006] In the rotor disclosed in Patent Literature 1, the adhesive sheet interposed between the permanent magnet and the rotor core has an adhesive layer which is expanded by heating and a base material layer which holds the above-described adhesive layer. In the rotor of Patent Literature 1, the adhesive layer is adhered to the permanent magnet. Further, in the above-described rotor, the base material layer which is not an expansion member is in contact with the inner surface of the slit hole of the rotor core. Therefore, in the rotor of Patent Literature 1, the adhesion of the adhesive sheet to the inner surface of the slit hole is sometimes insufficient, and the positioning accuracy of the permanent magnet with respect to the rotor core is sometimes insufficient.

[0007] Therefore, in a rotor in which a rotor magnet is inserted into a magnet insertion hole of a rotor core, a structure in which the rotor magnet can be easily and highly accurately positioned in the magnet insertion hole is required. SUMMARY

[0008] An object of the present application is to provide a rotor in which a rotor magnet inserted into a magnet insertion hole of a rotor core can be easily and highly accurately positioned in the magnet insertion hole.

[0009] The rotor of one embodiment of the present application includes a cylindrical rotor core having a magnet insertion hole that penetrates in an axial direction, a rotor magnet inserted into the magnet insertion hole, and a positioning member that positions the rotor magnet in the magnet insertion hole. The positioning member has a first foamed layer containing a bonding material that bonds with the rotor magnet, a second foamed layer that is in contact with an inner surface of the magnet insertion hole of the rotor core, and a base material layer between the first foamed layer and the second foamed layer. The first foamed layer, the second foamed layer, and the base material layer are in a stacked state between the rotor magnet and the inner surface of the magnet insertion hole.

[0010] The IPM motor according to an embodiment of the present application includes the rotor and a stator having a stator coil and a stator core.

[0011] The rotor according to one embodiment of the present application can easily and highly accurately position a rotor magnet in a magnet insertion hole of a rotor core. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is a cross-sectional view showing an outline structure of an IPM motor according to an embodiment of the present application.

[0013] Figure 2 FIG. 2 is a plan view of a rotor.

[0014] Figure 3 FIG. 3 is a partial enlarged view of FIG. 2. Figure 2

[0015] Figure 4 FIG. 4 is an IV-IV line cross-sectional view of FIG. 3. Figure 3

[0016] Figure 5 FIG. 5 is a view showing an outline structure of a positioning member before foaming.

[0017] Figure 6A FIG. 6 is a view showing a manufacturing method of a rotor according to an embodiment of the present application.

[0018] Figure 6B FIG. 7 is a view showing a manufacturing method of a rotor according to an embodiment of the present application.

[0019] Figure 6C FIG. 8 is a view showing a manufacturing method of a rotor according to an embodiment of the present application.

[0020] Figure 7A FIG. 9 is a view showing a position of a rotor magnet before heating.

[0021] Figure 7B FIG. 10 is a view showing a position of a rotor magnet after heating.

[0022] (SYMBOL EXPLANATION)​​

[0023] 1 motor (IPM motor)

[0024] 2 rotor

[0025] 3 stator

[0026] 4 housing

[0027] 6 positioning piece

[0028] 7 adhesive surface cover

[0029] 20 shaft

[0030] 21 rotor core

[0031] 22 rotor magnet

[0032] 23 positioning member

[0033] 24 magnet insertion hole

[0034] 24a insertion hole inner side surface

[0035] 24b insertion hole outer side surface

[0036] 25 core plate

[0037] 26 through hole

[0038] 27 pair of protrusions

[0039] 31 stator core

[0040] 36 stator coil

[0041] 51 magnet inner side surface

[0042] 52 magnet outer side surface

[0043] 55 magnet side foamed layer (first foamed layer)

[0044] 55a adhesive surface

[0045] 56 rotor core side foamed layer (second foamed layer)

[0046] 57 base material layer

[0047] 61 base material sheet

[0048] 62 rotor core side foamed sheet

[0049] 63 magnet side foamed sheet

[0050] 63a adhesive surface

[0051] P center axis DETAILED DESCRIPTION

[0052] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts in the drawings will be labeled with the same reference numerals without repeating their descriptions. Also, the dimensions of the constituent parts in the drawings do not faithfully represent the actual dimensions of the constituent parts or the dimensional ratios of each constituent part.

[0053] Furthermore, in the following description of motor 1, the direction parallel to the central axis P of rotor 2 is referred to as the "axial direction," the direction orthogonal to the central axis P is referred to as the "radial direction," and the direction along the arc centered on the central axis P is referred to as the "circumferential direction." However, there is no intention to limit the orientation of rotor 2 during use based on this definition. Additionally, the "long side direction" and "short side direction" of rotor magnet 22 and magnet insertion hole 24 refer to the long side direction and short side direction of rotor magnet 22 and magnet insertion hole 24 when rotor 2 is viewed along the axial direction.

[0054] Furthermore, in the following explanation, the expressions "fixed," "connected," and "installed" (hereinafter referred to as "fixed, etc.") include not only cases where parts are directly fixed to each other, but also cases where they are fixed via other parts. That is, in the following explanation, the expression "fixed, etc." includes the meaning of parts being directly and indirectly fixed to each other.

[0055] (Implementation Method 1)

[0056] (Structure of a motor)

[0057] Figure 1 The schematic structure of a motor 1, which is an IPM motor having a rotor 2 as an exemplary embodiment of the present invention, is shown. Motor 1 includes a rotor 2, a stator 3, a housing 4, and a shaft 20. The rotor 2 is a rotor for an IPM motor in which magnets are embedded within the rotor. The rotor 2 rotates relative to the stator 3 about a central axis P. In this embodiment, motor 1 is a so-called internal rotor type motor in which the rotor 2 is rotatable about a central axis P within a cylindrical stator 3.

[0058] The rotor 2 includes a rotor core 21, a rotor magnet 22, and a positioning component 23. The rotor 2 is located radially inside the stator 3 and is capable of rotating relative to the stator 3.

[0059] The rotor core 21 is cylindrical, extending along the central axis P. The shaft 20, extending along the central axis P, is fixed to the rotor core 21 in a axial direction. Thus, the rotor core 21 and the shaft 20 rotate together.

[0060] The rotor core 21 is constructed by stacking multiple circular core plates 25 along the thickness direction. The multiple core plates 25 are made of electromagnetic steel plates.

[0061] The rotor core 21 has a magnet insertion hole 24 that penetrates in the axial direction in a state in which a plurality of core plates 25 are stacked in the thickness direction. The magnet insertion hole 24 is, for example, rectangular when the rotor core 21 is viewed in the axial direction. The plurality of core plates 25 each have a through-hole 26 that constitutes the magnet insertion hole 24.

[0062] The rotor magnet 22 is in the shape of a rectangular parallelepiped that extends in the axial direction. That is, the rotor magnet 22 is rectangular when the rotor core 21 is viewed in the axial direction. The length of the rotor magnet 22 in the axial direction is equal to or slightly shorter than the length of the rotor core 21 in the axial direction. The rotor magnet 22 is positioned at a prescribed position by the positioning member 23 in a state in which the rotor magnet 22 is housed in the magnet insertion hole 24. Hereinafter, a face that constitutes a long side of the rotor magnet 22 when the rotor magnet 22 is viewed in the axial direction will be referred to as a long side face of the rotor magnet 22, and a face that constitutes a short side of the rotor magnet 22 will be referred to as a short side face of the rotor magnet 22. A detailed explanation of the positioning member 23 will be given later.

[0063] The stator 3 is housed in the housing 4. In the present embodiment, the stator 3 is in the shape of a cylinder. The rotor 2 is located on the radially inner side of the stator 3. That is, the stator 3 is located at a position that is diametrically opposite the rotor 2. The rotor 2 is rotatably located on the radially inner side of the stator 3 with the center axis P as the center.

[0064] The stator 3 has a stator core 31 and a stator coil 36. The stator core 31 is in the shape of a cylinder that extends in the axial direction. The stator coil 36 is wound around the stator core 31. The stator 3 has the same structure as a general stator. Therefore, a detailed explanation of the stator 3 will be omitted.

[0065] Next, the rotor 2 will be explained in detail with reference to Figures 2 to 4 to FIG. 6.

[0066] Figure 2 is a view of the rotor 2 viewed in the axial direction. As shown in Figure 2 In the present embodiment, the rotor core 21 has 24 magnet insertion holes 24. The rotor magnet 22 is housed in each of the 24 magnet insertion holes 24. In the present embodiment, the number of magnet insertion holes 24 is 24, but the number of magnet insertion holes 24 can be a number other than 24.

[0067] Sixteen of the 24 magnet insertion holes 24 have their long sides inclined relative to a radial line extending radially along the rotor 2. Eight of the 24 magnet insertion holes 24 have their long sides orthogonal to the radial line. Thus, in this embodiment, the long sides of all the magnet insertion holes 24 are not aligned with the aforementioned radial line. Therefore, in all the magnet insertion holes 24, one of the pairs of faces constituting the long side of the inner surface of the magnet insertion hole 24, when viewed from the axial direction, is located radially inner to the rotor core 21 than the other. In the following description, the radially inner face of the aforementioned pair is referred to as the inner insertion hole face 24a, and the radially outer face is referred to as the outer insertion hole face 24b. Alternatively, the position and long side direction of the magnet insertion holes 24 can also be... Figure 2 The positions shown and positions other than the long side direction.

[0068] Figure 3 It is Figure 2 The enlarged image shows the portion enclosed by the dashed line. (See image below.) Figure 3 As shown, one of the two long-side surfaces of the rotor magnet 22 inserted into the magnet insertion hole 24 is located radially inner to the rotor core 21 than the other. In the following description, the radially inner surface of the pair of long-side surfaces is referred to as the inner surface 51 of the magnet, and the radially outer surface is referred to as the outer surface 52 of the magnet. With the rotor magnet 22 inserted into the magnet insertion hole 24, the outer surface 52 of the magnet is opposite to the outer surface 24b of the insertion hole of the magnet insertion hole 24. The positioning member 23, described later, is located between the inner surface 51 of the magnet and the inner surface 24a of the insertion hole of the magnet insertion hole 24.

[0069] The rotor core 21 has a pair of protrusions 27 on the inner surface 24a of the insertion hole, protruding into the magnet insertion hole 24. One of the protrusions 27 faces one short side of the rotor magnet 22 when the rotor magnet 22 is housed in the magnet insertion hole 24, and the other protrusion faces the other short side of the rotor magnet 22 when the rotor magnet 22 is housed in the magnet insertion hole 24. That is, the pair of protrusions 27 restrict the movement of the rotor magnet 22 along the long side within the magnet insertion hole 24.

[0070] The positioning component 23 is composed of a component that is foamed by heating. The positioning component 23 is located between the inner surface 51 of the rotor magnet 22 and the inner surface 24a of the insertion hole 24. When expanded due to foaming, the positioning component 23 fills the gap between the inner surface of the rotor magnet 22 and the inner surface of the magnet insertion hole 24 within the magnet insertion hole 24.

[0071] Figure 4 yes Figure 3 A cross-sectional view along line IV-IV. (See attached image.) Figure 3 andFigure 4 As shown, the positioning member 23 is configured by laminating sheet-like members. In the positioning member 23, from the side that contacts the rotor magnet 22, a magnet-side foamed layer 55, a base material layer 57, and a rotor core-side foamed layer 56 are laminated in this order. The magnet-side foamed layer 55 corresponds to the first foamed layer. The rotor core-side foamed layer 56 corresponds to the second foamed layer.

[0072] The magnet-side foamed layer 55 contains a thermosetting resin and a foaming agent that foams by heating. As the foaming agent, a microcapsule in which a low-melting organic solvent such as an alcohol or the like is built in is often used. The thermosetting resin is preferably composed of a thermosetting adhesive. As the thermosetting adhesive, for example, a phenol-based adhesive, a polyurethane-based adhesive, an epoxy-based adhesive, or the like can be given. Among them, the epoxy-based adhesive is more preferable in terms of adhesive strength, resistance to chemicals, and the like. In addition, when an adhesive other than the epoxy-based adhesive is used as the thermosetting resin, curing failure can occur.

[0073] The magnet-side foamed layer 55 has an adhesive surface 55a on one surface. The magnet-side foamed layer 55 is adhered to the magnet inner surface 51 of the rotor magnet 22 via the adhesive surface 55a. The magnet-side foamed layer 55 is positioned between the rotor magnet 22 and the base material layer 57 in a state of being cured after foaming.

[0074] The rotor core-side foamed layer 56 is composed of the same member as the magnet-side foamed layer 55. The rotor core-side foamed layer 56 does not have an adhesive surface. The rotor core-side foamed layer 56 is in contact with the inner surface of the magnet insertion hole 24. The rotor core-side foamed layer 56 is positioned between the inner surface of the magnet insertion hole 24 and the base material layer 57 in a state of being cured after foaming.

[0075] The base material layer 57 is a member composed of a resin. As the resin, for example, polyethylene terephthalate (PET), polyphenylene sulfide (PSS), polyethylene naphthalate (PEN), polyimide (PI), or the like can be given.

[0076] The base material layer 57 is positioned between the magnet-side foamed layer 55 and the rotor core-side foamed layer 56 in the lamination direction of the positioning member 23. The base material layer 57 holds the magnet-side foamed layer 55 and the rotor core-side foamed layer 56. When the positioning member 23 is viewed from the axial direction, in the long edge direction of the rotor magnet 22, one end of the base material layer 57 is positioned at the inner side of the rotor magnet 22 more than one end of the rotor magnet 22, and the other end of the base material layer 57 is positioned at the inner side of the rotor magnet 22 more than the other end of the rotor magnet 22.

[0077] The rotor magnet 22 is pressed by the positioning member 23 toward the radially outer side of the rotor core 21 in the magnet insertion hole 24 of the rotor core 21. Thus, the rotor magnet 22 is positioned at a predetermined position in the radial direction of the rotor core 21 in the magnet insertion hole 24 of the rotor core 21.

[0078] Thus, the rotor magnet 22 is positioned at a predetermined position in the magnet insertion hole 24 by the pair of protrusions 27 and the positioning member 23.

[0079] In the present embodiment, the positioning member 23 is positioned only on the radially inner side of the rotor magnet 22 in the radial direction of the rotor 2.

[0080] When the rotor 2 rotates, a centrifugal force is generated on the rotor magnet 22. At this time, in the case where the positioning member 23 is positioned on the radially outer side of the rotor magnet 22 in the radial direction of the rotor 2, the positioning member 23 can be deteriorated because the positioning member 23 is compressed by the centrifugal force generated in the rotor magnet 22. In contrast, in the present embodiment, the positioning member 23 is positioned only on the radially inner side of the rotor magnet 22 in the radial direction of the rotor 2. Thus, even in the case where the centrifugal force is generated in the rotor magnet 22, the positioning member 23 is not compressed by the rotor magnet 22. Therefore, it is possible to prevent the positioning member 23 from being deteriorated by the centrifugal force generated in the rotor magnet 22. Thus, it is possible to prevent the decrease in the holding force of the positioning member 23 to the rotor magnet 22. Thus, it is possible to position the rotor magnet 22 at a predetermined position in the magnet insertion hole 24 with high precision.

[0081] In the present embodiment, the rotor magnet 22 is rectangular when the rotor magnet 22 is viewed in the axial direction, and the rotor core 21 has a pair of protrusions 27 on the inner surface of the magnet insertion hole 24 when the rotor core 21 is viewed in the axial direction. One of the pair of protrusions 27 faces a short side of one end portion in the long side direction of the rotor magnet 22 in a state where the rotor magnet 22 is inserted into the magnet insertion hole 24, and the other protrusion faces a short side of the other end portion in the long side direction of the rotor magnet 22 in the state where the rotor magnet 22 is inserted into the magnet insertion hole 24. The positioning member 23 is positioned only between the long side of the rotor magnet 22 and the inner surface of the magnet insertion hole 24 when the positioning member 23 is viewed in the axial direction.

[0082] Thus, the position of the rotor magnet 22 with respect to the long side direction of the magnet insertion hole 24 is determined by the pair of protrusions 27 on the inner surface of the magnet insertion hole 24 of the rotor core 21. In addition, the position of the rotor magnet 22 with respect to the short side direction of the magnet insertion hole 24 is determined by the positioning member 23. Thus, it is possible to easily position the rotor magnet 22 in the magnet insertion hole 24.

[0083] In addition, a pair of protrusions 27 are located on both sides of the positioning component 23. When the positioning component 23 is viewed from the axial direction, the substrate layer 57 of the positioning component 23 is located on the long side of the rotor magnet 22. One end of the substrate layer 57 is located closer to the inner side of the rotor magnet 22 than one end of the rotor magnet 22, and the other end of the substrate layer 57 is located closer to the inner side of the rotor magnet 22 than the other end of the rotor magnet 22.

[0084] In this way, by making the substrate layer 57 of the positioning component 23 shorter than the length of the long side of the rotor magnet 22 in the long side direction, interference between the foamed magnet-side foam layer 55 and the rotor core-side foam layer 56 and the pair of protrusions 27 that determine the position of the rotor magnet 22 in the long side direction can be suppressed. As a result, the rotor magnet 22 can be positioned with higher precision in the long side direction of the rotor magnet 22 within the magnet insertion hole 24.

[0085] (Manufacturing method of rotor)

[0086] Next, refer to Figure 5 The method for manufacturing the rotor 2 having the above structure will be described up to Figure 7.

[0087] The manufacturing process of rotor 2 includes: bonding process S1, which involves bonding the positioning piece 6 to rotor magnet 22; insertion process S2, which involves inserting the rotor magnet 22 with the positioning piece 6 bonded to it into the magnet insertion hole 24 of rotor core 21; and heating process S3, which involves heating the rotor core 21 with the rotor magnet 22 inserted into the magnet insertion hole 24.

[0088] Figure 5 This is a diagram showing the schematic structure of the positioning piece 6. The positioning piece 6 functions as the positioning component 23 through foaming. Figure 5 As shown, the positioning piece 6 is formed by stacking three sheet-like materials of the same size—a substrate sheet 61, a rotor core-side foam sheet 62, and a magnet-side foam sheet 63—in the thickness direction. The rotor core-side foam sheet 62 is foamed to form a rotor core-side foam layer 56. The magnet-side foam sheet 63 is foamed to form a magnet-side foam layer 55. The substrate sheet 61 is the substrate layer 57 of the positioning component 23. The rotor core-side foam sheet 62, the substrate sheet 61, and the magnet-side foam sheet 63 are stacked sequentially. The side of the magnet-side foam sheet 63 opposite to the side of the substrate sheet 61 is the adhesive surface 63a. The adhesive surface 63a is covered by an adhesive surface cover 7. Alternatively, the positioning piece 6 and the adhesive surface cover 7 can also be formed by overlapping the rotor core-side foam sheet 62, the substrate sheet 61, the magnet-side foam sheet 63, and the adhesive surface cover 7, and then cutting them to a specified size.

[0089] The size of the positioning piece 6 is smaller than the size of the long side surface of the rotor magnet 22. In addition, in a state where the rotor magnet 22 is inserted into the magnet insertion hole 24, the thickness of the positioning piece 6 is smaller than the gap between the long side surface of the rotor magnet 22 and the inner surface of the magnet insertion hole 24.

[0090] In the bonding process S1, the positioning piece 6 is bonded to the rotor magnet 22. In detail, as shown in Figure 6A , the bonding surface cover 7 is removed from the positioning piece 6, and the bonding surface 63a is exposed. After that, as shown in Figure 6B , the bonding surface 63a is bonded to the center of the magnet inner side surface 51 of the rotor magnet 22. That is, in a state where the positioning piece 6 is bonded to the magnet inner side surface 51, the magnet inner side surface 51 has a portion where the positioning piece 6 is not bonded in the outer peripheral portion.

[0091] In the insertion process S2, the rotor magnet 22 to which the positioning piece 6 is bonded is inserted into the magnet insertion hole 24 of the rotor core 21. In detail, as shown in Figure 6C , the rotor magnet 22 is inserted between the pair of protrusions 27 in the magnet insertion hole 24 of the rotor core 21 in a state where the face of the rotor magnet 22 to which the positioning piece 6 is bonded faces the radial inner side of the rotor core 21. In the state where the positioning piece 6 is bonded, the size in the thickness direction of the rotor magnet 22 is smaller than the size between the insertion hole inner side surface 24a and the insertion hole outer side surface 24b of the magnet insertion hole 24. Therefore, it is possible to easily insert the rotor magnet 22 in the state where the positioning piece 6 is bonded into the magnet insertion hole 24.

[0092] Figure 7A is a view of the magnet insertion hole 24 and the rotor magnet 22 after the rotor magnet 22 is inserted, as viewed in the axial direction. As shown in Figure 7A , the position in the long direction of the rotor magnet 22 is determined by the pair of protrusions 27. That is, the position in the long direction of the rotor magnet 22 is determined. On the other hand, a gap is generated between the rotor magnet 22 and the positioning piece 6 and the inner surface of the magnet insertion hole 24.

[0093] In the heating process S3, the rotor core 21 is heated in a state where the rotor magnet 22 is inserted into the magnet insertion hole 24. Figure 7B is a view of the magnet insertion hole 24 and the rotor magnet 22 after heating, as viewed in the axial direction. By heating, the positioning piece 6 expands between the magnet inner side surface 51 of the rotor magnet 22 and the insertion hole inner side surface 24a of the magnet insertion hole 24. That is, by the positioning piece 6, which is the positioning member 23 after foaming, the rotor magnet 22 is urged radially outward in the magnet insertion hole 24. Thus, the rotor magnet 22 is positioned at a prescribed position in the radial direction in the magnet insertion hole 24.

[0094] By manufacturing the rotor 2 using the above method, it is possible to obtain a rotor 2 that can easily and highly accurately position the rotor magnet 22 at a prescribed position within the magnet insertion hole 24.

[0095] As described above, the rotor 2 of the present embodiment includes the cylindrical rotor core 21 having the magnet insertion hole 24 that penetrates in the axial direction, the rotor magnet 22 inserted into the magnet insertion hole 24, and the positioning member 23 that positions the rotor magnet 22 within the magnet insertion hole 24. The positioning member 23 has the magnet-side foamed layer 55 that contains the adhesive material that adheres to the rotor magnet 22, the rotor-core-side foamed layer 56 that contacts the inner surface of the magnet insertion hole 24 of the rotor core 21, and the base material layer 57 that is positioned between the magnet-side foamed layer 55 and the rotor-core-side foamed layer 56. The magnet-side foamed layer 55, the rotor-core-side foamed layer 56, and the base material layer 57 are positioned between the rotor magnet 22 and the inner surface of the magnet insertion hole 24 in a stacked state.

[0096] In the above structure, the magnet-side foamed layer 55 and the rotor-core-side foamed layer 56 of the positioning member 23 are respectively positioned between the rotor magnet 22 and the inner surface of the magnet insertion hole 24 in a foamed state. That is, the magnet-side foamed layer 55 and the rotor-core-side foamed layer 56 are positioned between the rotor magnet 22 and the inner surface of the magnet insertion hole 24 in a state of expanding in the thickness direction due to foaming. The magnet-side foamed layer 55 adheres to the rotor magnet 22. The rotor-core-side foamed layer 56 contacts the inner surface of the magnet insertion hole 24. Thereby, it is possible to adhere the positioning member 23 to the rotor magnet 22 and to tightly contact the inner surface of the magnet insertion hole 24. Therefore, by the positioning member 23, it is possible to easily position the rotor magnet 22 at a prescribed position in the radial direction with respect to the magnet insertion hole 24 of the rotor core 21.

[0097] In addition, in the above structure, since the positioning member 23 has a plurality of foamed layers, it is possible to increase the volume of foaming compared to a structure in which the positioning member 23 has one foamed layer. Thereby, it is possible to more strongly press the rotor magnet 22 against the inner surface of the magnet insertion hole 24 by the positioning member 23. Therefore, by the positioning member 23, it is possible to more highly accurately position the rotor magnet 22 with respect to the magnet insertion hole 24 of the rotor core 21.

[0098] Further, the rotor 2 is obtained by foaming the above-mentioned foaming layers of the positioning sheet 6, for example, by inserting the rotor magnet 22 to which the positioning sheet 6 having a plurality of foaming layers is adhered into the magnet insertion hole 24 of the rotor core 21. Specifically, the positioning sheet 6 having a plurality of foaming layers functioning as the magnet side foaming layer 55 and the rotor core side foaming layer 56 by foaming is adhered to the rotor magnet 22, and the above-mentioned plurality of foaming layers of the positioning sheet 6 are foamed after the rotor magnet 22 and the positioning sheet 6 are inserted into the magnet insertion hole 24. By foaming the positioning sheet 6, the positioning member 23 adhered to the rotor magnet 22 and closely adhered to the inner surface of the magnet insertion hole 24 can be obtained. Therefore, in the rotor 2, the rotor magnet 22 can be easily positioned in the magnet insertion hole 24. Therefore, the rotor 2 in which the rotor magnet 22 can be easily and highly accurately positioned in the magnet insertion hole 24 of the rotor core 21 can be provided.

[0099] In the present embodiment, the rotor core 21 has a plurality of core plates 25 having a through-hole 26 and stacked in the thickness direction, and a magnet insertion hole 24 constituted by the through-holes 26 of the plurality of core plates 25 in a state in which the plurality of core plates 25 are stacked.

[0100] In a case in which the rotor core 21 has a plurality of core plates 25 stacked in the thickness direction, the inner surface of the magnet insertion hole 24 is constituted by the inner edges of the through-holes 26 of the plurality of core plates 25. The plurality of core plates 25 have a tolerance with respect to each other. Therefore, the inner surface of the magnet insertion hole 24 constituted by stacking the plurality of core plates 25 has a concave-convex surface due to the above-mentioned tolerance. The base material layer 57 of the positioning member 23 does not expand along the concave-convex surface of the inner surface of the magnet insertion hole. Therefore, in a structure in which the base material layer is in contact with the inner surface of the magnet insertion hole, the close adhesion of the positioning member with respect to the inner surface of the magnet insertion hole is insufficient. In contrast to this, as described above, in a structure in which the rotor core side foaming layer 56 of the positioning member 23 is in contact with the inner surface of the magnet insertion hole 24, the rotor core side foaming layer 56 of the positioning member 23 expands along the concave-convex surface of the inner surface of the magnet insertion hole 24. Therefore, the rotor magnet 22 can be more reliably held in the magnet insertion hole 24 by the positioning member 23.

[0101] The motor 1 of the present embodiment has the rotor 2 having the above-mentioned structure, and a stator 3 having a stator coil 36 and a stator core 31.

[0102] The motor 1 in which the rotor 2 in which the rotor magnet 22 can be easily and highly accurately positioned in the magnet insertion hole 24 by the positioning member 23 can be provided.

[0103] (Other Embodiments)

[0104] The above describes embodiments of the present application, but the above-described embodiments are merely examples for implementing the present application. Therefore, the present application is not limited to the above-described embodiments, and the above-described embodiments can be appropriately modified and implemented without departing from the scope of the gist of the present application.

[0105] In the above-described embodiment, the rotor core 21 has a pair of protrusions 27. However, the rotor core can not have a pair of protrusions.

[0106] In the above-described embodiment, the rotor core 21 has a pair of protrusions 27 on the insertion hole inner side surface 24a that protrude into the magnet insertion hole 24. However, the rotor core can have a pair of protrusions at other positions on the inner surface of the magnet insertion hole.

[0107] In the above-described embodiment, the positioning member 23 is located between the magnet inner side surface 51 of the rotor magnet 22 and the insertion hole inner side surface 24a of the magnet insertion hole 24. However, the positioning member can be located at any position between the rotor magnet and the inner surface of the magnet insertion hole. The positioning member can be located between the magnet outer side surface of the rotor magnet and the insertion hole outer side surface. The positioning member can be located between the short side surface of the rotor magnet and the inner surface of the magnet insertion hole.

[0108] In the above-described embodiment, the size of the base material layer 57 of the positioning member 23 is smaller than the size of the long side surface of the rotor magnet 22. However, the size of the base material layer of the positioning member can be the same as the size of the long side surface of the rotor magnet.

[0109] In the above-described embodiment, the size of the positioning sheet 6 is smaller than the size of the long side surface of the rotor magnet 22. However, the size of the positioning sheet can be the same as the size of the long side surface of the rotor magnet.

[0110] The present application can be used for a rotor of an IPM motor.

Claims

1. A rotor, comprising: A cylindrical rotor core having a magnet insertion hole extending along the axial direction; A rotor magnet, wherein the rotor magnet is inserted into the magnet insertion hole; as well as A positioning component that positions the rotor magnet within the magnet insertion hole. in, The positioning component has: A first foam layer, the first foam layer containing an adhesive material that bonds to the rotor magnet; A second foam layer is formed, which contacts the inner surface of the magnet insertion hole in the rotor core, and the surface of the second foam layer that contacts the inner surface of the magnet insertion hole is not an adhesive surface; and A substrate layer is located between the first foam layer and the second foam layer. The first foam layer, the second foam layer, and the substrate layer are stacked and located between the inner surface of the rotor magnet and the magnet insertion hole. The positioning component is located only radially inside the rotor magnet in the radial direction of the rotor. The first foam layer and the second foam layer make the rotor magnet contact the inner surface of the magnet insertion hole on the radially outer side through foaming.

2. The rotor as claimed in claim 1, wherein, The rotor core has: Multiple iron core plates, wherein the multiple iron core plates have through holes and are stacked along the thickness direction; as well as The magnet insertion hole is formed by the through holes of the multiple iron core plates in the state of the multiple iron core plates being stacked.

3. The rotor as claimed in claim 1, wherein, The positioning component is located radially inside the rotor magnet in the radial direction of the rotor.

4. The rotor as claimed in claim 2, wherein, The positioning component is located radially inside the rotor magnet in the radial direction of the rotor.

5. The rotor as claimed in any one of claims 1 to 4, wherein, The rotor magnet appears rectangular when viewed along the axial direction. When viewed along the axial direction, the rotor core has a pair of protrusions on the inner surface of the magnet insertion hole. One of the pair of protrusions faces the short side of the end of the rotor magnet located in the long side direction when the rotor magnet is inserted into the magnet insertion hole. The other of the pair of protrusions faces the shorter side of the rotor magnet located at the other end in the long side direction when the rotor magnet is inserted into the magnet insertion hole. When viewed along the axial direction, the positioning component is located only between the long side of the rotor magnet and the inner surface of the magnet insertion hole.

6. The rotor as claimed in claim 5, wherein, The pair of protrusions are located on both sides of the positioning component. In the substrate layer of the positioning component, when the positioning component is viewed along the axial direction, in the long side direction of the rotor magnet, one end of the substrate layer is located closer to the inside of the rotor magnet than one end of the rotor magnet, and the other end of the substrate layer is located closer to the inside of the rotor magnet than the other end of the rotor magnet.

7. An IPM motor, comprising: The rotor according to any one of claims 1 to 6; and A stator having stator coils and a stator core.

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