Rotating electric machine core and rotating

Abstract

A core section (22) for a rotating electrical machine, wherein a plurality of core body pieces (24) having a plurality of magnetic pole forming sections (32) at equal intervals in the circumferential direction are laminated in the axial direction. Each of the plurality of core sheets has a first fitting portion (43) and a second fitting portion (45). One of the first fitting part and the second fitting part is formed in a convex shape protruding in the axial direction, and the other of the first fitting part and the second fitting part is formed in a concave shape recessed in the axial direction. A pair of core pieces that overlap in the axial direction are joined to each other by the fitting of the first fitting portion of one core piece and the second fitting portion of the other core piece. The first fitting part and the second fitting part provided in the same core sheet are provided at positions that do not overlap each other in the axial direction.

Description

Citation of related applications

[0001] This application is based on Japanese Patent Application No. 2022-145329 filed on September 13, 2022, and the contents thereof are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to a core of a rotating electric machine and the rotating electric machine. Background Art

[0003] For example, the rotor core of the rotating electric machine disclosed in Patent Document 1 includes a plurality of core sheets stacked in the axial direction. Each core sheet has a convex portion and a concave portion formed by a stamping process. In detail, by pressing a punch axially relative to one surface of the core sheet, a concave portion is formed on the one surface, and a convex portion is formed on the surface on the opposite side thereof. The core sheets stacked in the axial direction are coupled to each other by fitting the convex portion of one core sheet into the concave portion of another core sheet. In addition, in the rotor of Patent Document 1, magnetic poles are formed by permanent magnets buried in the rotor core. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2022-122982 Summary of the invention

[0005] In the rotor as described above, in the case of realizing a skewed structure in which the magnetic poles are circumferentially offset within the axial range, it is necessary to form a convex portion and a concave portion on the back side thereof in a circumferentially offset manner in the same core piece. In this case, by circumferentially offsetting the die and punch used in the stamping process of the convex portion, the convex portion and the concave portion on the back side thereof can be circumferentially offset. However, in this stamping process, it is difficult to increase the circumferential offset amount of the convex portion and the concave portion. Therefore, in order to ensure the desired circumferential displacement amount in the skewed structure of the magnetic poles, it is necessary to increase the axial length of the rotor core, etc., which imposes restrictions on the design of the rotor core.

[0006] An object of the present disclosure is to provide a core portion of a rotating electric machine and a rotating electric machine capable of easily ensuring the displacement amount of a skew structure in the circumferential direction. In the first mode of the present disclosure, the core of a rotating electric machine is formed by stacking a plurality of core pieces having a plurality of magnetic pole forming parts at equal intervals in the circumferential direction in an axial direction, wherein each of the plurality of core pieces has a first interlocking portion and a second interlocking portion, one of the first interlocking portion and the second interlocking portion is formed into a convex shape protruding in the axial direction, and the other of the first interlocking portion and the second interlocking portion is formed into a concave shape recessed in the axial direction, and a pair of the axially overlapping core pieces are combined with each other by interlocking the first interlocking portion of one core piece with the second interlocking portion of the other core piece, and the first interlocking portion and the second interlocking portion arranged in the same core piece are arranged at positions that do not overlap each other in the axial direction.

[0007] In a second embodiment of the present disclosure, a rotating electric machine includes a rotor having a rotor core and a stator having a stator core, wherein at least one of the rotor core and the stator core is formed by stacking a plurality of core sheets having a plurality of magnetic pole forming portions at equal intervals in the circumferential direction in an axial direction, each of the plurality of core sheets has a first interlocking portion and a second interlocking portion, one of the first interlocking portion and the second interlocking portion is formed into a convex shape protruding in the axial direction, and the other of the first interlocking portion and the second interlocking portion is formed into a concave shape recessed in the axial direction, and a pair of the axially overlapping core sheets are combined with each other by interlocking the first interlocking portion of one core sheet with the second interlocking portion of the other core sheet, and the first interlocking portion and the second interlocking portion arranged in the same core sheet are arranged at positions that do not overlap each other in the axial direction.

[0008] According to the core of the rotating electrical machine and the rotating electrical machine, the first fitting portion and the second fitting portion are formed independently of each other. Therefore, the second fitting portion can be set at a higher degree of freedom in the position where it is formed, and as a result, the circumferential displacement of the skew structure can be easily ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. Figure 1 It is a structural diagram of a rotating electrical machine in the embodiment. Figure 2 It is a top view showing a part of the core sheet in this embodiment. Figure 3 1 is a plan view showing a second magnetic pole forming portion in the core piece according to this embodiment. Figure 4 It is an explanatory diagram showing a stacking method of each core piece in the rotor core of this embodiment. Figure 5 It is an explanatory diagram showing the method of connecting the core pieces in the rotor core of this embodiment. Figure 6 Schematic diagram showing a skewed structure of magnetic poles in the rotor of this embodiment. Figure 7 Schematic diagram showing a skewed structure of magnetic poles in a rotor according to a modified example. Figure 8 Schematic diagram showing a skewed structure of magnetic poles in a rotor according to a modified example. Fig. 9 1 is a cross-sectional view showing a second fitting portion in a rotor core according to a modified example. Fig.10 It is a perspective view showing a core sheet according to a modified example. DETAILED DESCRIPTION

[0010] Hereinafter, a core portion of a rotating electrical machine and one embodiment of the rotating electrical machine will be described. Figure 1 The rotating electric machine M of the present embodiment shown is constituted by an embedded magnet type brushless motor. The rotating electric machine M includes a substantially annular stator 10 and a substantially cylindrical rotor 20 rotatably disposed in a radially inner space of the stator 10. The stator 10 applies a rotating magnetic field to the rotor 20.

[0011] (Stator 10) The stator 10 includes a stator core 11 that is roughly annular. The stator core 11 is made of a magnetic metal material. The stator core 11 is, for example, composed of a plurality of core sheets stacked in the direction of the central axis L1. The plurality of core sheets are, for example, made of electromagnetic steel plates. The stator core 11 has, for example, twelve pole teeth 12. The pole teeth 12 extend radially inward and are arranged at equal intervals in the circumferential direction. The pole teeth 12 have the same shape as each other. The front end portion of the pole tooth 12, i.e., the radial inner end portion, is roughly T-shaped, and the front end face 12a is in the shape of an arc along the outer circumferential surface of the rotor 20.

[0012] The pole teeth 12 are wound with windings 13, for example, by concentrated winding. The windings 13 are three-phase wired, such as Figure 1 When power is supplied to the winding 13, a rotating magnetic field is generated in the stator 10 for driving the rotor 20 to rotate. In the stator 10 described above, the outer peripheral surface of the stator core 11 is fixed to the inner peripheral surface of the housing 14.

[0013] (Rotor 20) The rotor 20 has a rotating shaft 21, a rotor core 22, and a plurality of permanent magnets 23. The rotor core 22 is substantially cylindrical. The rotating shaft 21 is inserted into the center of the rotor core 22. A plurality of permanent magnets 23 are embedded in the rotor core 22. For example, eight permanent magnets 23 are provided in the rotor core 22. The rotor 20 is configured to be rotatable relative to the stator 10 by supporting the rotating shaft 21 with a bearing (not shown) provided in the housing 14.

[0014] (Structure of the Core Sheet 24) The rotor core 22 is composed of Figure 2 The core pieces 24 shown are stacked in the axial direction. Each core piece 24 is made of, for example, an electromagnetic steel plate made of a magnetic metal material. In the present embodiment, each core piece 24 is formed in the same shape as each other.

[0015] like Figure 2 As shown, the core piece 24 has a shaft insertion hole 31 for the rotation shaft 21 to be inserted and a plurality of magnetic pole forming portions 32 located around the shaft insertion hole 31. The plurality of magnetic pole forming portions 32 are arranged at equal intervals in the circumferential direction of the rotor core 22. In addition, in the following description, the circumferential direction of the rotor core 22, the axial direction of the rotor core 22, and the radial direction of the rotor core 22 are sometimes referred to as the circumferential direction, the axial direction, and the radial direction, respectively.

[0016] The rotor 20 of the present embodiment is composed of, for example, eight poles. That is, in each core piece 24, eight magnetic pole forming parts 32 are arranged at 45° intervals in the circumferential direction. The eight magnetic pole forming parts 32 respectively have a magnet hole 33. Each magnet hole 33 is a hole that penetrates the core piece 24 in the axial direction. The magnet holes 33 are formed in the same shape in each magnetic pole forming part 32. A permanent magnet 23 is arranged inside each magnet hole 33. When each magnet hole 33 is observed from the axial direction, it is formed into a folded shape protruding toward the radial inner side. That is, each magnet hole 33 is roughly V-shaped when observed from the axial direction. The eight magnet holes 33 are arranged at equal intervals in the circumferential direction.

[0017] The eight magnetic pole forming portions 32 each have an outer core portion 34 as a portion radially outward of the magnet hole 33. The outer core portion 34 is a portion of the core piece 24 formed on the inner side of the V-shaped return shape of the magnet hole 33. The outer core portion 34 functions as a portion that obtains magnetic resistance torque relative to the stator 10. When viewed from the axial direction, the outer core portion 34 is in a roughly triangular shape toward one vertex in the direction toward the central axis L1 of the core piece 24.

[0018] The eight magnetic pole forming portions 32 of the present embodiment are constituted by four first magnetic pole forming portions 41 and four second magnetic pole forming portions 42. The four first magnetic pole forming portions 41 and the four second magnetic pole forming portions 42 are alternately arranged in the circumferential direction.

[0019] In the present embodiment, for example, a connecting portion 35 is provided in the magnet hole 33 of each first magnetic pole forming portion 41. The connecting portion 35 connects the outer core portion 34 to the portion around the shaft insertion hole 31 of the core piece 24 at the V-shaped curved portion of the radial inner end of the magnet hole 33. In addition, no connecting portion such as the connecting portion 35 is provided in the magnet hole 33 of each second magnetic pole forming portion 42.

[0020] (Structure of the First Fitting Portion 43) Each core piece 24 has a first fitting portion 43. The first fitting portion 43 is provided in the outer core portion 34 of each first magnetic pole forming portion 41. That is, four first fitting portions 43 are provided in each core piece 24.

[0021] like Figure 5 As shown, the first interlocking portion 43 is convex and protrudes in the axial direction. The first interlocking portion 43 is formed by stamping the core sheet 24. On the back side of the first interlocking portion 43, there is a recessed portion 44 formed when the first interlocking portion 43 is stamped. That is, by pressing a punch not shown in the figure into one surface of the core sheet 24 in the axial direction, a recessed portion 44 is formed on the one surface of the core sheet 24, and the first interlocking portion 43 is formed on the surface on the opposite side thereof. Therefore, the shapes of the first interlocking portion 43 and the recessed portion 44 when viewed from the axial direction are approximately the same. In the present embodiment, the first interlocking portion 43 and the recessed portion 44 are circular when viewed from the axial direction. The first interlocking portion 43 and the recessed portion 44 are not offset in the circumferential direction. That is, the center 43a of the first interlocking portion 43 and the center 44a of the recessed portion 44 are located on the same straight line L2 along the axial direction.

[0022] (Structure of the Second Fitting Portion 45) like Figure 2 As shown, each core piece 24 has a second interlocking portion 45. The second interlocking portion 45 is provided in the outer core portion 34 of each second magnetic pole forming portion 42. That is, four second interlocking portions 45 are provided in each core piece 24. In addition, the first interlocking portions 43 and the second interlocking portions 45 are alternately provided in the circumferential direction with respect to the eight magnetic pole forming portions 32.

[0023] The second interlocking portion 45 is concave in the axial direction. Specifically, the second interlocking portion 45 is a through hole that penetrates the core sheet 24 in the axial direction. The second interlocking portion 45 is circular when viewed from the axial direction. Each first interlocking portion 43 and each second interlocking portion 45 are arranged on the same circle centered on the central axis L1.

[0024] As described above, the first fitting portion 43 is provided in the first magnetic pole forming portion 41, and the second fitting portion 45 is provided in the second magnetic pole forming portion 42. That is, the first fitting portion 43 and the second fitting portion 45 provided in the same core piece 24 are provided at positions not overlapping each other in the axial direction.

[0025] (Regarding the Configuration of the First Fitting Section 43 and the Second Fitting Section 45) The pitch angle θ1 of the plurality of magnetic pole forming portions 32 is the angle between the circumferential centers of the respective magnetic pole forming portions 32. That is, the pitch angle θ1 of the plurality of magnetic pole forming portions 32 is θ1 = 360° / P, with the number of poles of the rotor 20 being P. Therefore, the pitch angle θ1 of the present embodiment is 45°. In addition, in the present embodiment, the angle formed by the circumferential center C1 of the first magnetic pole forming portion 41 and the circumferential center C2 of the second magnetic pole forming portion 42 is the same as the pitch angle θ1, which is 45°.

[0026] The first fitting portion 43 is provided so that its center 43a is located on the circumferential center C1 of the first magnetic pole forming portion 41. On the other hand, the second fitting portion 45 is provided so that its center 45a is circumferentially offset from the circumferential center C2 of the second magnetic pole forming portion 42 by an offset angle θ2.

[0027] In addition, the first fitting portion 43 is provided at the circumferential center of the outer core portion 34. Thus, the first fitting portion 43 can be provided at a position away from the circumferential edge of the outer core portion 34 away from the first magnetic pole forming portion 41, that is, at the circumferential inner edge of the magnet hole 33. Therefore, by providing the first fitting portion 43 at a position close to the circumferential edge of the outer core portion 34, a reduction in the rigidity of the outer core portion 34 can be avoided.

[0028] like Figure 3 As shown, when the distance r is set from the center axis L1 of the core piece 24 to the center 45a of the second interlocking portion 45, the offset distance D of the second interlocking portion 45 relative to the circumferential center C2 of the second magnetic pole forming portion 42 is D≈r×sin(θ2). The offset distance D is set to a length of more than one tenth of the plate thickness t of the core piece 24. That is, the relationship between the above-mentioned distance r, the offset angle θ2 of the second interlocking portion 45, and the plate thickness t of the core piece 24 is constituted to satisfy 0.1t≤r×sin(θ2). In addition, the second interlocking portion 45 is arranged in a manner such that the center 45a is located radially outward of the radial center line 34a of the outer core portion 34 of the second magnetic pole forming portion 42.

[0029] like Figure 5 As shown, among the plurality of core pieces 24 stacked in the axial direction, a pair of core pieces 24 stacked in the axial direction are connected to each other by the first interlocking portion 43 of one core piece 24 and the second interlocking portion 45 of the other core piece 24. Thus, in the state where each core piece 24 is stacked, the first magnetic pole forming portion 41 and the second magnetic pole forming portion 42 are alternately overlapped in the axial direction.

[0030] like Figure 4As shown, a plurality of core pieces 24 are stacked, for example, with each other rotating by a transposition angle θa around the central axis L1. The transposition angle θa of the present embodiment is θa=θ1+θ2. That is, the core pieces 24 stacked in the axial direction are rotated by an angle obtained by adding the spacing angle θ1 and the offset angle θ2 of the plurality of magnetic pole forming portions 32.

[0031] As described above, each core piece 24 is connected to each other by the interlocking of the first interlocking portion 43 and the second interlocking portion 45. Moreover, the center 43a of the first interlocking portion 43 is located on the circumferential center C1 of the first magnetic pole forming portion 41, and in contrast, the center 45a of the second interlocking portion 45 deviates from the circumferential center C2 of the second magnetic pole forming portion 42 by an offset angle θ2. As a result, the magnetic pole forming portions 32 of each core piece 24 are stacked axially in a state where every other piece is staggered circumferentially by an offset angle θ2. That is, the magnetic poles of the rotor core 22 formed by the axially stacked magnetic pole forming portions 32 are formed into a so-called skewed structure that is circumferentially displaced from one axial end of the rotor core 22 toward the other end.

[0032] Figure 6 The rotor core 22 is shown in which a plurality of core pieces 24 are stacked in the above manner. In this figure, on the outer peripheral surface of the rotor core 22, a deflection line L3 is shown that depicts the circumferential center (i.e., circumferential center C1, C2) of the magnetic pole forming portion 32 of each core piece 24 stacked in the axial direction. Figure 6 and the following Figure 7 and Figure 8 In the figure, for the sake of convenience, the detailed shape of the core piece 24 such as the magnet hole 33 is omitted. As shown by the skew line L3, the axially stacked magnetic pole forming portion 32 is formed into a so-called skewed structure that is circumferentially displaced from one axial end toward the other end of the rotor core 22. The circumferential displacement of the skewed structure is determined by the offset angle θ2 of the second interlocking portion 45 and the number of stacked core pieces 24.

[0033] The magnet holes 33 of each axially stacked magnetic pole forming portion 32 are shifted circumferentially along the deflection line L3 from one axial end toward the other end of the rotor core 22. In addition, the permanent magnet 23 is arranged in the accommodation space formed by connecting the magnet holes 33 of each core piece 24 along the deflection line L3.

[0034] The permanent magnet 23 is composed of, for example, a bonded magnet filled in the above-mentioned receiving space formed by connecting the magnet holes 33. As a result, the permanent magnet 23 is formed into a substantially V-shaped folded shape protruding radially inward when viewed from the axial direction. In addition, the permanent magnet 23 is displaced along the deflection line L3 and in the circumferential direction as it moves from one axial end of the rotor core 22 toward the other end. In addition, as the magnetic powder used in the permanent magnet 23, for example, a samarium iron nitride (SmFeN) magnet can be used, but other rare earth magnets can also be used. The magnetic poles of the rotor 20 are composed of the axially stacked magnetic pole forming portion 32 and the permanent magnet 23 arranged in the receiving space formed by the magnet holes 33 of the magnetic pole forming portion 32.

[0035] The operation of this embodiment will be described. The magnetic poles of the rotor core 22 are formed into a skewed structure that is displaced in the circumferential direction from one end toward the other end in the axial direction of the rotor core 22. Therefore, the cogging torque generated by the rotary electric machine M can be suppressed to be small.

[0036] The effects of this embodiment will be described. (1) Among the plurality of core sheets 24 stacked in the axial direction, a pair of core sheets 24 overlapping in the axial direction are connected to each other by the engagement of the first engagement portion 43 of one core sheet 24 with the second engagement portion 45 of the other core sheet 24. Furthermore, the first engagement portion 43 and the second engagement portion 45 provided in the same core sheet 24 are provided at positions that do not overlap each other in the axial direction.

[0037] Here, as a comparative structure relative to the present embodiment, a structure in which each core piece 24 is combined by fitting the first fitting portion 43 of the core piece 24 into the recess on the back side of the first fitting portion 43 of the core piece 24 adjacent in the axial direction is described. In the above comparative structure, in the case of realizing the skewed structure of the magnetic poles of the rotor 20, it is necessary to stagger the first fitting portion 43 and the recess on its back side in the circumferential direction. In this case, by staggering the die and punch used for the stamping process of the first fitting portion 43 in the circumferential direction, the first fitting portion 43 and the recess on its back side can be staggered in the circumferential direction. However, in this stamping process, it is difficult to increase the circumferential offset amount between the first fitting portion 43 and the recess. Therefore, in order to ensure the desired displacement amount of the skewed structure, it is necessary to increase the axial length of the rotor core 22, etc., which restricts the design of the rotor core 22.

[0038] In view of this, in the present embodiment, in the same core piece 24, the first interlocking portion 43 and the second interlocking portion 45 are arranged at positions that do not overlap each other in the axial direction. That is, the first interlocking portion 43 and the second interlocking portion 45 are configured to be independent of each other in terms of molding. Therefore, the second interlocking portion 45 has a high degree of freedom in setting the formation position, and as a result, the offset angle θ2 of the second interlocking portion 45 can be ensured to be large. Therefore, since the circumferential displacement of the skew structure can be easily ensured, the design of the rotor core 22 is not easily restricted.

[0039] (2) In each core piece 24, a plurality of magnetic pole forming portions 32 include a first magnetic pole forming portion 41 provided with a first interlocking portion 43 and a second magnetic pole forming portion 42 provided with a second interlocking portion 45. The center 43a of the first interlocking portion 43 is set at the circumferential center C1 of the first magnetic pole forming portion 41. The center 45a of the second interlocking portion 45 is set at a position offset in the circumferential direction relative to the circumferential center C2 of the second magnetic pole forming portion 42. According to this structure, by interlocking the first interlocking portion 43 of the core piece 24 with the second interlocking portion 45 of the axially adjacent core piece 24, the magnetic poles of the rotor 20 formed by the axially stacked magnetic pole forming portions 32 can be set to a skewed structure.

[0040] (3) The relationship among the distance r from the central axis L1 of the core sheet 24 to the center 45a of the second interlocking portion 45, the offset angle θ2 of the second interlocking portion 45, and the plate thickness t of the core sheet 24 satisfies 0.1t≤r×sin(θ2). According to this structure, by increasing the setting freedom of the formation position of the second interlocking portion 45, it is easy to set the circumferential offset distance D (D≈r×sin(θ2)) of the second interlocking portion 45 to more than one tenth of the plate thickness t of the core sheet 24. Therefore, it is possible to eliminate design constraints such as reducing the distance r from the central axis L1 of the core sheet 24 to the center 45a of the second interlocking portion 45 in order to ensure the offset angle θ2 of the second interlocking portion 45.

[0041] (4) The plurality of core pieces 24 are stacked in a state where every other core piece is rotated by a transposition angle θa. Furthermore, when the spacing angle of the plurality of magnetic pole forming parts 32 is set to θ1 and the offset angle of the second interlocking part 45 is set to θ2, the transposition angle θa is θa=θ1+θ2. According to this structure, the core pieces 24 stacked in the axial direction can be stacked in a state where the rotation angle is the sum of the spacing angle θ1 of the plurality of magnetic pole forming parts 32 and the offset angle θ2.

[0042] (5) The plurality of magnetic pole forming portions 32 are configured by alternately arranging a plurality of first magnetic pole forming portions 41 provided with first interlocking portions 43 and a plurality of second magnetic pole forming portions 42 provided with second interlocking portions 45 in the circumferential direction. According to this structure, the first interlocking portions 43 and the second interlocking portions 45 can be alternately arranged in the circumferential direction with respect to the plurality of magnetic pole forming portions 32. Thus, in the core pieces 24 overlapped in the axial direction, the number of interlocking portions of the first interlocking portions 43 and the second interlocking portions 45 can be ensured to be half the number of the magnetic pole forming portions 32.

[0043] (6) The first interlocking portion 43 is convex and protrudes in the axial direction, and the second interlocking portion 45 is a through hole that penetrates the core piece 24 in the axial direction. The second interlocking portion 45 as a through hole has a larger magnetic resistance than the first interlocking portion 43. Therefore, by offsetting the second interlocking portion 45 from the circumferential center C2 of the second magnetic pole forming portion 42 having a higher magnetic flux density, the influence on the magnetic characteristics can be suppressed to a smaller extent.

[0044] (7) The offset angles θ2 of the second fitting portions 45 of the core pieces 24 are all the same. According to this configuration, the core pieces 24 can be made to have the same shape. (8) The second fitting portion 45 is a through hole that penetrates the core sheet 24 in the axial direction. According to this structure, the second fitting portion 45 into which the convex first fitting portion 43 fits can be easily formed.

[0045] (9) Each core piece 24 has a recessed portion 44 formed on the back side of the first fitting portion 43 when the first fitting portion 43 is press-formed. Moreover, the center 43a of the first fitting portion 43 and the center 44a of the recessed portion 44 are located on the same straight line L2 along the axial direction. According to this structure, the shape of the first fitting portion 43 formed by the press working can be formed with high precision.

[0046] (10) In each core piece 24, the plurality of magnetic pole forming portions 32 each have a magnet hole 33 for placing the permanent magnet 23 therein. The magnet hole 33 is formed in a folded shape protruding radially inward. With this structure, the size of the outer core portion 34 that contributes to the reluctance torque can be ensured.

[0047] (11) In each core piece 24, the plurality of magnetic pole forming portions 32 each have an outer core portion 34 as a portion radially outward of the magnet hole 33. The first interlocking portion 43 and the second interlocking portion 45 are respectively provided in the outer core portion 34. According to this structure, the magnet hole 33 is V-shaped, so that the area of ​​the outer core portion 34 can be ensured. Therefore, by setting the formation position of the first interlocking portion 43 and the second interlocking portion 45 in the outer core portion 34, the degree of freedom in setting the formation position of the first interlocking portion 43 and the second interlocking portion 45 can be increased.

[0048] (12) The second fitting portion 45 is provided so that its center 45a is located radially outward from the radial center line 34a of the outer core portion 34 of the second magnetic pole forming portion 42. When the formation position of the second fitting portion 45 is offset in the circumferential direction due to manufacturing error, the more the second fitting portion 45 is located radially inward (that is, the smaller the distance r is), the greater the error of the offset angle θ2 becomes. Therefore, by locating the second fitting portion 45 radially outward from the radial center line 34a, the error of the offset angle θ2 can be suppressed to be small.

[0049] (13) The first fitting portion 43 is circular when viewed from the axial direction. Thus, the stress around the first fitting portion 43 can be made uniform. Similarly, the second fitting portion 45 is circular when viewed from the axial direction. Thus, the stress around the second fitting portion 45 can be made uniform.

[0050] (14) Only one first fitting portion 43 or second fitting portion 45 is provided in each magnetic pole forming portion 32. The first fitting portion 43 and the second fitting portion 45 are the main factors that hinder the flow of magnetic flux in the magnetic pole forming portion 32. Therefore, by minimizing the number of first fitting portions 43 or second fitting portions 45 provided in one magnetic pole forming portion 32, it is possible to suppress the flow of magnetic flux in each magnetic pole forming portion 32 from being deteriorated.

[0051] The present embodiment can be implemented by making the following modifications. The present embodiment and the following modifications can be implemented in combination with each other within the scope of no technical contradiction. The plurality of core pieces 24 forming the rotor core 22 may include core pieces 24 having different offset angles θ2 of the second fitting portions 45 .

[0052] For example, in Figure 7 In the rotor core 22 shown, the first core sheet group 51 and the second core sheet group 52 overlap in the axial direction. The first core sheet group 51 is composed of a plurality of core sheets 24 of the same shape stacked together. The plurality of core sheets 24 constituting the first core sheet group 51 are respectively first core sheets 24a. The shapes of the plurality of first core sheets 24a are the same as each other. In addition, the plurality of core sheets 24 constituting the second core sheet group 52 are respectively set as second core sheets 24b. The shapes of the plurality of second core sheets 24b are the same as each other.

[0053] Here, the offset angle θ2 of the second fitting portion 45 in the first core piece 24a is set to α°, and the offset angle θ2 of the second fitting portion 45 in the second core piece 24b is set to β°. Figure 7In the example shown, when α is a positive value, β is a negative value. That is, the second interlocking portion 45 of the second core piece 24b is offset in the opposite direction relative to the second interlocking portion 45 of the first core piece 24a. Thus, in the skewed structure of the magnetic poles of the rotor 20, the circumferential displacement on one side of the axial direction can be made in opposite directions in the first core piece group 51 and the second core piece group 52. Therefore, the axial thrust generated by the skewed structure of the magnetic poles of the rotor 20 is in opposite directions in the first core piece group 51 and the second core piece group 52. Therefore, the thrust of the rotor 20 as a whole, which is obtained by adding the thrusts generated by the first core piece group 51 and the second core piece group 52, can be suppressed to be smaller.

[0054] In addition, Figure 7 In the example shown, the absolute values ​​of α as a positive value and β as a negative value are set equal. Thus, in the skewed structure of the magnetic poles of the rotor 20, the displacement in the circumferential direction on one side of the axial direction can be made equal in the first core sheet group 51 and the second core sheet group 52. Thus, the thrust generated by each of the first core sheet group 51 and the second core sheet group 52 can be offset, and the thrust generated by the rotor 20 as a whole can be suppressed to a smaller level. In addition, Figure 8 An example is shown in which α is set to a positive value and α<β is set.

[0055] ·like Fig. 9 As shown, the second fitting portion 45 may be a recessed portion that does not penetrate the core piece 24. According to this structure, the magnetic resistance of the second fitting portion 45 can be suppressed to be small compared with the case where the second fitting portion 45 is formed as a through hole.

[0056] In the core sheet 24 of the above embodiment, only one concavo-convex group consisting of a plurality of first fitting parts 43 and a plurality of second fitting parts 45 arranged on the same circle centered on the central axis L1 is provided. However, the present invention is not particularly limited to this, and two or more such concavo-convex groups may be provided.

[0057] For example, Fig.10 The core sheet 24 shown has a first concave-convex group 61 composed of a plurality of first fitting parts 43 and a plurality of second fitting parts 45 arranged on a first reference circle X1 centered on the central axis L1. In addition, the core sheet 24 has a second concave-convex group 62 composed of a plurality of first fitting parts 43 and a plurality of second fitting parts 45 arranged on a second reference circle X2 centered on the central axis L1. The diameter of the second reference circle X2 is smaller than that of the first reference circle X1.

[0058] In the first concave-convex group 61, the first fitting portion 43 and the second fitting portion 45 are, for example, alternately arranged in the circumferential direction relative to the plurality of magnetic pole forming portions 32. In addition, in the second concave-convex group 62, for example, the first fitting portion 43 and the second fitting portion 45 are alternately arranged in the circumferential direction relative to the plurality of magnetic pole forming portions 32. Here, among the plurality of magnetic pole forming portions 32, the magnetic pole forming portion 32 provided with the first fitting portion 43 of the first concave-convex group 61 is used as the first magnetic pole forming portion 41, and the magnetic pole forming portion 32 provided with the second fitting portion 45 of the first concave-convex group 61 is used as the second magnetic pole forming portion 42. In each first magnetic pole forming portion 41, a first fitting portion 43 of the first concave-convex group 61 and a second fitting portion 45 of the second concave-convex group 62 are provided. In each second magnetic pole forming portion 42, a second fitting portion 45 of the first concave-convex group 61 and a first fitting portion 43 of the second concave-convex group 62 are provided. The first fitting portion 43 of each of the first and second concavo-convex groups 61 and 62 is disposed at the circumferential center of the magnetic pole forming portion 32. The second fitting portion 45 of each of the first and second concavo-convex groups 61 and 62 is disposed at a position offset from the circumferential center of the magnetic pole forming portion 32 in the circumferential direction.

[0059] In each of the first concavo-convex group 61 and the second concavo-convex group 62, the first fitting portion 43 and the second fitting portion 45 in the same concavo-convex group correspond to each other. That is, in a state where each core sheet 24 is stacked, the first fitting portion 43 of the first concavo-convex group 61 fits with the second fitting portion 45 of the first concavo-convex group 61 of the adjacent core sheet 24. In addition, the first fitting portion 43 of the second concavo-convex group 62 fits with the second fitting portion 45 of the second concavo-convex group 62 in the adjacent core sheet 24.

[0060] according to Fig.10 The structure shown can improve the bonding strength of each core piece 24 stacked in the axial direction through the first concave-convex group 61 and the second concave-convex group 62. In addition, in each of the first concave-convex group 61 and the second concave-convex group 62, the diameters of the first reference circle X1 and the second reference circle X2, which are the references for the positions of the first interlocking portion 43 and the second interlocking portion 45, are different from each other. As a result, in one magnetic pole forming portion 32, the first interlocking portion 43 and the second interlocking portion 45 are not arranged in the circumferential direction. Therefore, by arranging the first interlocking portion 43 and the second interlocking portion 45 at a position close to the circumferential edge of the outer core portion 34, it is possible to avoid a reduction in the rigidity of the outer core portion 34.

[0061] In addition, in this structure, one first fitting portion 43 and one second fitting portion 45 are provided in each magnetic pole forming portion 32. That is, the second fitting portion 45 is not provided in one magnetic pole forming portion 32, which includes both the first concave-convex group 61 and the second concave-convex group 62. Therefore, a plurality of second fitting portions 45 having a greater magnetic resistance than the first fitting portion 43 are not provided in one magnetic pole forming portion 32, and as a result, an increase in magnetic resistance in the magnetic pole forming portion 32 can be suppressed.

[0062] In addition, Fig.10 In the structure shown in the figure, the first concave-convex group 61 and the second concave-convex group 62 may each have a first fitting portion 43 in each first magnetic pole forming portion 41, and the first concave-convex group 61 and the second concave-convex group 62 may each have a second fitting portion 45 in each second magnetic pole forming portion 42. Fig.10 In the structure shown, the core sheet 24 includes only two concave-convex groups (the first concave-convex group 61 and the second concave-convex group 62), but is not limited thereto and may include more than three concave-convex groups. In addition, even when more than three concave-convex groups are provided, the reference circle serving as the configuration reference of the concave-convex groups is set to a different diameter in each concave-convex group.

[0063] In the core piece 24 of the above embodiment, the centers 43 a and 45 a of the first fitting portion 43 and the second fitting portion 45 may be set radially inward of the radial center line 34 a of the outer core portion 34 .

[0064] In the above embodiment, the transposition angle θa is not limited to θa=θ1+θ2, but can be changed as appropriate. That is, in the above embodiment, the transposition angle θa may be θa=(θ1×(2N-1))+θ2 (where N is an integer greater than or equal to 1).

[0065] A plurality of core pieces 24 may be stacked in a state rotated by the transposition angle θa. In this case, the core pieces 24 that are not stacked in the rotated state are coupled to each other by the engagement of the first engagement portion 43 and the recessed portion 44 .

[0066] In the core piece 24 of the above-mentioned embodiment, the first interlocking portion 43 and the second interlocking portion 45 are alternately arranged in the circumferential direction relative to the plurality of magnetic pole forming portions 32, but it is not particularly limited thereto. For example, it may be a structure in which the plurality of first interlocking portions 43 and the plurality of second interlocking portions 45 are continuously arranged in the circumferential direction. In addition, it is not necessary to provide the first interlocking portion 43 or the second interlocking portion 45 in all of the plurality of magnetic pole forming portions 32. For example, the first interlocking portion 43 and the second interlocking portion 45 may be alternately arranged relative to every other magnetic pole forming portion 32 in the circumferential direction. In addition, according to the configuration of the first interlocking portion 43 and the second interlocking portion 45, the transposition angle θa can be set to θa=(θ1×N)+θ2 (where N is an integer greater than 1).

[0067] The center 43a of the first fitting portion 43 may be set at a position offset in the circumferential direction relative to the circumferential center C1 of the first magnetic pole forming portion 41. In this case, the offset angle of the first fitting portion 43 needs to be different from the offset angle θ2 of the second fitting portion 45. With such a structure, the degree of freedom of the configuration of the first fitting portion 43 can be increased.

[0068] In the above-mentioned embodiments and Fig.10 In the core sheet 24 shown, the concave-convex relationship between the first fitting portion 43 and the second fitting portion 45 may be reversed. That is, the first fitting portion 43 may be concave in the axial direction, and the second fitting portion 45 may be convex in the axial direction.

[0069] The number of poles of the rotor 20, that is, the number of magnetic pole forming portions 32 in one core piece 24 is not limited to eight in the above-described embodiment, and may be set to seven or less or nine or more. The shape of the magnet hole 33 when viewed in the axial direction is not limited to the above embodiment, and may be a U-shape or other folded shape protruding radially inward of the core piece 24. Also, a shape other than the folded shape such as an I-shape may be used.

[0070] The first fitting portion 43 and the second fitting portion 45 in the above-described embodiment can be applied to form a core piece of the stator core 11 . Although the present disclosure is described based on the embodiments, it should be understood that the present disclosure is not limited to the above embodiments and structures. The present disclosure also includes various modifications and modifications within the scope of equivalents. In addition, various combinations and methods, and other combinations and methods including only one element, above or below them, also belong to the scope and concept of the present disclosure.

[0071] (Note) The features of the present disclosure are as follows. [1] A core of a rotating electric machine, wherein the core (22) of the rotating electric machine is formed by stacking a plurality of core pieces (24) having a plurality of magnetic pole forming portions (32) at equal intervals in the circumferential direction in an axial direction, wherein each of the plurality of core pieces has a first interlocking portion (43) and a second interlocking portion (45), one of the first interlocking portion and the second interlocking portion is formed into a convex shape protruding in the axial direction, and the other of the first interlocking portion and the second interlocking portion is formed into a concave shape recessed in the axial direction, and a pair of the axially overlapping core pieces are connected to each other by interlocking the first interlocking portion of one core piece with the second interlocking portion of the other core piece, and the first interlocking portion and the second interlocking portion arranged in the same core piece are arranged at positions that do not overlap each other in the axial direction.

[0072] [2] A core portion of a rotating electrical machine as described in [1], wherein in each of the core pieces, the plurality of magnetic pole forming portions include a first magnetic pole forming portion (41) provided with the first engaging portion and a second magnetic pole forming portion (42) provided with the second engaging portion, the center (43a) of the first engaging portion being set at the circumferential center (C1) of the first magnetic pole forming portion, and the center (45a) of the second engaging portion being set at a position offset circumferentially relative to the circumferential center (C2) of the second magnetic pole forming portion.

[0073] [3] A core portion of a rotating electrical machine as described in [1], wherein in each of the core pieces, the plurality of magnetic pole forming portions include a first magnetic pole forming portion (41) provided with the first engaging portion and a second magnetic pole forming portion (42) provided with the second engaging portion, the center (43a) of the first engaging portion being set at a position offset in the circumferential direction relative to the circumferential center (C1) of the first magnetic pole forming portion, and the center (45a) of the second engaging portion being set at a position offset in the circumferential direction relative to the circumferential center (C2) of the second magnetic pole forming portion.

[0074] [4] A core portion of a rotating electrical machine as described in [2], wherein the relationship between the distance r from the central axis (L1) of the core piece to the center of the second interlocking portion, the offset angle θ2 of the second interlocking portion, and the plate thickness t of the core piece satisfies 0.1t≤r×s in(θ2).

[0075] [5] A core portion of a rotating electrical machine as described in [2] or [4], wherein the plurality of core pieces are stacked in a state where every other piece or every other piece is rotated by a transposition angle θa, and when the spacing angle of the plurality of magnetic pole forming portions is set to θ1 and the offset angle of the second interlocking portion is set to θ2, the transposition angle θa is θa=(θ1×N)+θ2, where N is an integer greater than 1.

[0076] [6] The core portion of a rotating electrical machine as described in any one of [2] to [5], wherein the plurality of magnetic pole forming portions are formed by alternately arranging a plurality of the first magnetic pole forming portions and the second magnetic pole forming portions in a circumferential direction.

[0077] [7] A core portion of a rotating electrical machine as described in any one of [2] to [6], wherein the first engaging portion is formed into a convex shape protruding in the axial direction, and the second engaging portion is a through hole (45) penetrating the core piece in the axial direction.

[0078] [8] The core of a rotating electrical machine as described in any one of [2] to [7], wherein the offset angles (θ2) of the second engaging portions of the core pieces are all the same. [9] The core of a rotating electrical machine as described in any one of [2] to [7], wherein the plurality of core pieces include core pieces having different offset angles (θ2) of the second engaging portions.

[0079]

[10] The core of a rotating electrical machine as described in any one of [1] to [9], wherein the first engaging portion or the second engaging portion which is concave in the axial direction is a through hole (45) which penetrates the core sheet in the axial direction.

[0080]

[11] A core portion of a rotating electrical machine as described in any one of [1] to

[10] , wherein the first engaging portion is formed into a convex shape protruding in the axial direction, the second engaging portion is formed into a concave shape recessed in the axial direction, each of the core pieces has a concave portion (45) formed on the back side of the first engaging portion when the first engaging portion is stamped, and the center (43a) of the first engaging portion and the center (45a) of the concave portion are located on the same straight line (L2) along the axial direction.

[0081]

[12] A core of a rotating electric machine as described in any one of [1] to

[11] , wherein the core of the rotating electric machine is a rotor core (22) of a rotor (20) of a rotating electric machine (M), and in each of the core pieces, each of the plurality of magnetic pole forming portions has a magnet hole (33) for arranging a permanent magnet (23) inside, and the magnet hole is in a folded shape protruding radially inward.

[0082]

[13] A core portion of a rotating electrical machine as described in

[12] , wherein, in each of the above-mentioned core pieces, each of the above-mentioned multiple pole forming portions has an outer core portion (34) which is a portion radially outside the above-mentioned magnet hole, and the above-mentioned first interlocking portion and the above-mentioned second interlocking portion are respectively arranged on the above-mentioned outer core portion.

[0083]

[14] A core portion of a rotating electrical machine as described in any one of [1] to

[13] , wherein each of the core pieces comprises: a first concave-convex group (61), the first concave-convex group consisting of the first interlocking portion and the second interlocking portion arranged on a first reference circle (X1) centered on the central axis (L1) of the core piece; and a second concave-convex group (62), the second concave-convex group consisting of the first interlocking portion and the second interlocking portion arranged on a second reference circle (X2) centered on the central axis and having a diameter smaller than the first reference circle.

[0084]

[15] A rotating electric machine, the rotating electric machine (M) comprising a rotor (20) having a rotor core (22) and a stator (10) having a stator core (11), wherein at least one of the rotor core and the stator core is formed by stacking a plurality of core sheets (24) having a plurality of magnetic pole forming portions (32) at equal intervals in the circumferential direction in an axial direction, each of the plurality of core sheets having a first interlocking portion (43) and a second interlocking portion (45), one of the first interlocking portion and the second interlocking portion being formed into a convex shape protruding in the axial direction, and the other of the first interlocking portion and the second interlocking portion being formed into a concave shape recessed in the axial direction, a pair of the core sheets overlapping in the axial direction are connected to each other by interlocking the first interlocking portion of one core sheet with the second interlocking portion of the other core sheet, and the first interlocking portion and the second interlocking portion arranged in the same core sheet are arranged at positions that do not overlap each other in the axial direction.

Claims

1. A core of a rotating electric machine, wherein the core (22) of the rotating electric machine is stacked in an axial direction with a plurality of core pieces (24) having a plurality of magnetic pole forming portions (32) at equal intervals in a circumferential direction, Each of the plurality of core pieces has a first engaging portion (43) and a second engaging portion (45). One of the first fitting portion and the second fitting portion is formed into a convex shape protruding in the axial direction, The other of the first fitting portion and the second fitting portion is formed into a concave shape sunken in the axial direction, A pair of the core pieces overlapped in the axial direction are connected to each other by the engagement of the first engagement portion of one core piece with the second engagement portion of the other core piece. The first fitting portion and the second fitting portion provided in the same core piece are provided at positions not overlapping each other in the axial direction.

2. The core of a rotating electrical machine according to claim 1, characterized in that In each of the core pieces, the plurality of magnetic pole forming portions include a first magnetic pole forming portion (41) provided with the first fitting portion and a second magnetic pole forming portion (42) provided with the second fitting portion. The center (43a) of the first fitting portion is set at the circumferential center (C1) of the first magnetic pole forming portion. The center (45a) of the second fitting portion is set at a position offset in the circumferential direction relative to the circumferential center (C2) of the second magnetic pole forming portion.

3. The core of a rotating electrical machine according to claim 1, characterized in that In each of the core pieces, the plurality of magnetic pole forming portions include a first magnetic pole forming portion (41) provided with the first fitting portion and a second magnetic pole forming portion (42) provided with the second fitting portion. The center (43a) of the first engaging portion is set at a position offset in the circumferential direction relative to the circumferential center (C1) of the first magnetic pole forming portion. The center (45a) of the second fitting portion is set at a position offset in the circumferential direction relative to the circumferential center (C2) of the second magnetic pole forming portion.

4. The core of a rotating electrical machine according to claim 2, characterized in that The relationship among the distance r from the central axis (L1) of the core sheet to the center of the second fitting portion, the offset angle θ2 of the second fitting portion, and the plate thickness t of the core sheet satisfies 0.1t≤r×sin(θ2).

5. The core of a rotating electrical machine according to claim 2, characterized in that The plurality of core sheets are stacked in a state where every other sheet or every other plurality of sheets are rotated by a transposition angle θa. When the pitch angle of the plurality of magnetic pole forming portions is θ1 and the offset angle of the second fitting portion is θ2, the transposition angle θa is θa=(θ1×N)+θ2, where N is an integer greater than or equal to 1.

6. The core of a rotating electrical machine according to claim 2, characterized in that The plurality of magnetic pole forming portions are configured by alternately arranging a plurality of the first magnetic pole forming portions and a plurality of the second magnetic pole forming portions in a circumferential direction.

7. The core of a rotating electrical machine according to claim 2, characterized in that The first fitting portion is formed into a convex shape protruding in the axial direction, The second engaging portion is a through hole (45) that penetrates the core sheet in the axial direction.

8. The core of a rotating electrical machine according to claim 2, characterized in that The offset angles (θ2) of the second fitting portions of the core pieces are all the same.

9. The core of a rotating electrical machine according to claim 2, characterized in that The plurality of core pieces include core pieces having different offset angles (θ2) of the second engaging portions.

10. The core of a rotating electrical machine according to claim 1, characterized in that The first fitting portion or the second fitting portion, which is concave in the axial direction, is a through hole (45) that penetrates the core sheet in the axial direction.

11. The core of a rotating electrical machine according to claim 1, characterized in that The first fitting portion is formed into a convex shape protruding in the axial direction, The second fitting portion is formed into a concave shape that is recessed in the axial direction. Each of the core pieces has a recess (45) formed on the back side of the first engaging portion when the first engaging portion is stamped. The center (43a) of the first fitting portion and the center (45a) of the recessed portion are located on the same straight line (L2) along the axial direction.

12. The core of a rotating electrical machine according to claim 1, characterized in that The core of the rotating electrical machine is a rotor core (22) of a rotor (20) for a rotating electrical machine (M). In each of the core pieces, each of the plurality of magnetic pole forming portions has a magnet hole (33) for arranging a permanent magnet (23) therein. The magnet hole has a folded shape protruding radially inward.

13. The core of a rotating electrical machine according to claim 12, characterized in that In each of the core pieces, each of the plurality of magnetic pole forming portions has an outer core portion (34) which is located radially outside the magnet hole. The first fitting portion and the second fitting portion are respectively provided on the outer core portion.

14. The core of a rotating electrical machine according to claim 1, characterized in that Each of the core pieces comprises: a first concavo-convex group (61), the first concavo-convex group comprising the first fitting portion and the second fitting portion arranged on a first reference circle (X1) centered on the central axis (L1) of the core sheet; and A second concavo-convex group (62) includes the first fitting portion and the second fitting portion which are arranged on a second reference circle (X2) centered on the central axis and having a smaller diameter than the first reference circle.

15. A rotating electrical machine, the rotating electrical machine (M) comprising: A rotor (20) having a rotor core (22); as well as A stator (10) having a stator core (11), At least one of the rotor core and the stator core is formed by stacking a plurality of core pieces (24) having a plurality of magnetic pole forming portions (32) at equal intervals in the circumferential direction in an axial direction. Each of the plurality of core pieces has a first engaging portion (43) and a second engaging portion (45). One of the first fitting portion and the second fitting portion is formed into a convex shape protruding in the axial direction, The other of the first fitting portion and the second fitting portion is formed into a concave shape sunken in the axial direction, A pair of the core pieces overlapped in the axial direction are connected to each other by the engagement of the first engagement portion of one core piece with the second engagement portion of the other core piece. The first fitting portion and the second fitting portion provided in the same core piece are provided at positions not overlapping each other in the axial direction.

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