Rotary electric machine and rotor thereof

Abstract

The purpose of the present invention is to provide a rotor having a rotor core structure capable of improving torque. A rotor core (31) of this rotor is configured from an assembly of divided cores (311). The divided core (311) is provided with: a main pole magnet slot (312) into which the main pole magnet (321) is inserted; a d-axis core section (311a) positioned on the stator (2) side with respect to the main pole magnet slot (312); and a back yoke (311b) positioned on the opposite side from the d-axis core section (311a) with respect to the main pole magnet slot (312). The housing (33) is provided with a protruding section (332) that protrudes inward in the radial direction. The housing (33) including the protruding part (332) is made of a non-magnetic material. Every two adjacent split iron cores (311) and the corresponding protruding part (332) form a spoke magnet groove (313) for containing the corresponding spoke magnet (322). The split iron core (311) and the housing (33) are combined through a dovetail groove structure formed by the back yoke (311b) and the protruding part (332).

Description

Technical Field

[0001] This invention relates to a rotary electric motor and its rotor. Background Technology

[0002] Patent Document 1 describes a rotary electric machine having a rotor and a stator. The rotor includes magnets and a rotor core with magnet holes for inserting the magnets. The stator is positioned opposite the rotor with a predetermined gap. The magnets consist of main pole magnets with their main faces facing each other radially in the rotary electric machine and spoke magnets with their main faces facing each other circumferentially in the rotary electric machine. The rotor core has: a d-axis core formed between the gap and the main pole magnets; a magnet bridge formed between the main pole magnets and the spoke magnets; a gap surface opposite to the stator; and a counter-gap surface located on the radially opposite side of the gap surface. The length between the gap surface and the end of the spoke magnet on the counter-gap surface side is greater than or equal to the length between the end of the gap surface and the end of the main pole magnet on the counter-gap surface side (see abstract). The region of the rotor core further radially from the main pole magnets on the gap side is called the d-axis core. Conversely, the region located on the radially opposite side of the gap is called the back yoke. This back yoke is formed in a circumferentially connected shape on the counter-gap surface side of the main pole magnets and the spoke magnets (see paragraphs 0019 and 0019). Figure 3 (a) of 3, (b) of 3.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2023 / 286606 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The configuration of the main pole magnet and the spoke magnet in Patent Document 1 is called the Halbach arrangement.

[0008] In a rotor where the main pole magnets and spoke magnets are arranged in a Halbach configuration, magnetic flux entering from the S pole passes through the main pole magnet, then sequentially through the back yoke, spoke magnets, the back yoke on the N pole side, and finally the main pole magnet on the N pole side. In this rotor structure, the back yoke on the anti-gap side of the main pole magnet is the path for the magnetic flux required to generate torque, and is a necessary component of the magnetic circuit. In contrast, the back yoke on the anti-gap side of the spoke magnet is not only a path for the magnetic flux unnecessary for generating torque, but also creates a leakage flux flow path by short-circuiting the S and N poles of the spoke magnet. Therefore, the back yoke on the anti-gap side of the spoke magnet may become a major factor hindering torque increase.

[0009] The purpose of this invention is to provide a rotor with a rotor core structure that can improve torque.

[0010] Methods for solving problems

[0011] To achieve the above objectives, the rotary motor of the present invention comprises:

[0012] A magnet, a rotor core with the magnet inserted, and a housing for fixing the rotor core.

[0013] The magnet consists of a main pole magnet with its magnetization direction facing radially and a spoke magnet with its magnetization direction facing circumferentially.

[0014] The rotor core is composed of an assembly of segmented cores.

[0015] The segmented core includes: a main pole magnet slot into which the main pole magnet is inserted; a d-axis core portion disposed on the stator side relative to the main pole magnet slot; and a back yoke disposed on the side opposite to the d-axis core portion relative to the main pole magnet slot.

[0016] In the rotor of a rotating electric machine,

[0017] The housing has a protrusion that projects toward one side of the segmented iron core.

[0018] The housing including the protrusion is made of a non-magnetic material.

[0019] The two adjacent segmented iron cores and the protrusion form a spoke magnet slot that accommodates the spoke magnet.

[0020] The segmented core and the housing are joined by a dovetail groove structure formed by the back yoke and the two protrusions adjacent to the back yoke.

[0021] The effects of the invention

[0022] According to the present invention, it is possible to provide a rotor having a rotor core structure that can improve torque.

[0023] Other issues, structures, and effects not described above will become clear through the description of the manner in which the following invention is carried out. Attached Figure Description

[0024] Figure 1 This is an exploded perspective view of a rotary electric motor according to an embodiment of the present invention.

[0025] Figure 2 This is a top view of the rotor of an embodiment of the present invention, viewed from the axial direction.

[0026] Figure 3 yes Figure 2 An enlarged top view of section III of rotor 3 shown.

[0027] Figure 4 This is a diagram illustrating the subject matter of the rotor of a comparative example of the present invention.

[0028] Figure 5 It means Figure 3 An enlarged top view of a modified example of a split iron core (the first modified example).

[0029] Figure 6A It means Figure 3 An enlarged top view of a modified example of a split iron core (modified example 2).

[0030] Figure 6B It means Figure 3 A partial enlarged view of the modified example of the divided iron core (the second modified example).

[0031] Figure 7 It means Figure 3 An enlarged top view of a modified example of a split iron core (the third modified example).

[0032] Figure 8 This is a top view showing a portion of the rotor and stator when the rotor of the present invention is used to construct a rotary motor with fractional slot concentrated windings.

[0033] Figure 9 The figure illustrates the advantages of using the rotor of the present invention to construct a rotary motor with fractional slot concentrated windings.

[0034] Figure 10 This diagram illustrates the configuration of an xEV rotary motor employing an embodiment of the present invention. Detailed Implementation

[0035] The following describes embodiments of the present invention. In each embodiment and figure, the same reference numerals are used to refer to the same components to avoid repetition of the same description. Furthermore, if there are differences in the components to which the same reference numerals are used, those differences will be explained.

[0036] [Example 1]

[0037] use Figure 1 A rotary motor 1 according to an embodiment of the present invention will be described. Figure 1 This is an exploded perspective view of a rotary motor 1 according to an embodiment of the present invention.

[0038] The rotary electric motor 1 includes a stator 2 and a rotor 3 as main components. The stator 2 has a stator core 21, and the rotor 3 has a rotor core 31. In this embodiment, the stator 2 and rotor 3 are arranged such that the outer peripheral surface of the rotor core 31 faces the inner peripheral surface of the stator core 21. The stator 2 and rotor 3 are arranged without contacting each other, and a gap (air gap) is provided between the stator 2 and rotor 3. The rotary electric motor 1 may also include an end bracket 4 and a power conversion device 5 as other components.

[0039] In this embodiment, the rotary motor 1 is an inner rotor structure in which the rotor 3 is disposed on the inner circumference of the stator core 21, but it can also be an outer rotor structure in which the rotor 3 is disposed on the outer circumference of the stator core 21.

[0040] The stator 2 has a stator core 21 composed of multiple stacked iron core plates and coils 213 wound on the stator core 21. The stator core 21 has an annular stator back yoke 211, multiple teeth 212 connected to the stator back yoke 211 and arranged on the radially spaced side, and slots formed between the teeth. The stator core 21 may also be composed of a solid, integrally formed component. Alternatively, it may be composed of a powder magnetic material such as a pressed powder core, or it may be composed of amorphous metal or nanocrystalline material.

[0041] Coil 213 is wound and mounted in a manner that surrounds teeth 212 and slots. Coil 213 consists of: a slotted coil inserted into a slot, coil ends spanning between slots at different positions, and leads for inputting current from an external circuit or connecting coils at different positions to each other. To generate a rotating magnetic field in the gap, coil 213 is configured with, for example, U-phase, V-phase, and W-phase coils. The fundamental components of the input current are each 120° out of phase between the three-phase coils, thereby generating a rotating magnetic field in the gap. This rotating magnetic field is used to drive rotor 3.

[0042] The power conversion device 5 performs a switching operation, converting the DC power supplied by a battery or DC power source (not shown) into three-phase AC power. This three-phase AC power is supplied to the stator windings (not shown) of the stator 2, generating a rotating magnetic field on the stator 2. Additionally, in... Figure 1 In this configuration, the power conversion device 5 is housed inside the end bracket 4 and integrated with the rotary motor 1. However, the position of the power conversion device 5 is arbitrary; it may also be separate from the rotary motor 1. Furthermore, whether the rotary motor 1 has the end bracket 4 is arbitrary; the rotary motor 1 may also be without the end bracket 4.

[0043] Although Figure 1 It is not shown in the figure, but a rotating shaft is provided in rotor 3. Figure 1 The dashed line 1a represents the axis of rotation and its extension. That is, the dashed line 1a coincides with the axis of rotation of the rotor 3, which contains the axis of rotation. The rotor 3 and the stator 2 have the same central axis, and the central axis of the rotor 3 coincides with the axis of rotation 1a.

[0044] use Figure 2 The rotor 3 of one embodiment of the present invention will be described. Figure 2 This is a top view of the rotor 3 of an embodiment of the present invention, viewed from the Z-axis.

[0045] In the following description, "radial DR", "circumferential Dθ", and "axial DZ" are as follows: Figure 2 As shown, "Radial DR" is a straight line direction perpendicular to the rotation axis 1a, radiating outwards from the rotation axis 1a. "Circumferential Dθ" is the circumferential direction centered on the rotation axis 1a, representing the direction of rotation around the rotation axis 1a. "Axial DZ" is a straight line direction parallel to the rotation axis 1a, along the rotation axis 1a. Furthermore, "Inner Circumferential Side" and "Outer Circumferential Side" are defined as follows: the side closer to the rotation axis 1a is defined as "Inner Circumferential Side," and the side farther away is defined as "Outer Circumferential Side."

[0046] The rotor 3 has a rotor core 31 composed of an assembly of multiple segmented iron cores 311, magnets 32 disposed within the rotor core 31, and a housing 33 for fastening the multiple segmented iron cores 311. The rotor 3 has a pressing plate (not shown) that faces one end face 311a of the segmented iron cores 311 along the axial direction DZ, pressing the segmented iron cores 311 against the housing 33. The magnets 32 consist of a main pole magnet 321 with its magnetization direction facing radially and spoke magnets 322 with their magnetization direction facing circumferentially. Furthermore, to prevent the segmented iron cores 311 and magnets 32 from flying axially relative to the housing 33, it is preferable that the rotor 3 has a pressing plate, but it is also permissible to omit the pressing plate.

[0047] Rotor 3 rotates around a rotation axis 1a. A rotation shaft (not shown) may be fixed on rotor 3, and the rotary motor 1 may also have a frame covering stator 2 and rotor 3. Rotor 3 is connected to the load directly or via structural components such as a rotation shaft or frame, and rotation and torque are transmitted to the load through the rotation of rotor 3.

[0048] The rotor core 31 is composed of multiple stacked core plates. The rotor core 31 can also be composed of a single-piece solid component. Alternatively, the rotor core 31 can be composed of compressed powder magnetic materials such as pressed iron cores, or it can be composed of amorphous metals or nanocrystalline materials.

[0049] use Figure 3 The fastening structure of the split iron core 311 is explained. Figure 3 yes Figure 2 An enlarged top view of section III of rotor 3 shown.

[0050] The rotor 3 includes a magnet 32, a rotor core 31 into which the magnet 32 ​​is inserted, and a housing 33 for fixing the rotor core 31. The rotor core 31 is composed of an assembly of divided cores 311. The magnet 32 ​​is composed of a main pole magnet 321 with the magnetization direction facing radially and a spoke magnet 322 with the magnetization direction facing circumferentially.

[0051] The housing 33 is fixed to a rotating shaft (not shown) to secure the segmented iron core 311. The housing 33 has a protrusion (housing-side protrusion) 332 on its outer peripheral surface 311 that projects toward the segmented iron core 311 (in this embodiment, the outer peripheral side). The protrusion 332 of the housing 33 has a housing-side cone 332a, which has a tapered surface 332b whose circumferential width increases toward the segmented iron core 311. The housing 33, including the protrusion 332, is formed of a non-magnetic material.

[0052] In this embodiment, the protrusion 332 is formed by a housing-side conical portion 332a. The entire protrusion 332 forms the housing-side conical portion 332a, and the two sides of the protrusion 332 in the circumferential direction are formed by conical surfaces 332b.

[0053] The housing 33 has a recess (back yoke receiving portion) 333 between the two protrusions 332 to receive the back yoke 311a. The bottom surface 333a of the recess 333 is located between the two protrusions 332 and is formed by the outer peripheral surface 33a of the housing 33, which is opposite to the inner peripheral surface 311d of the back yoke 311a.

[0054] The segmented core 311 includes a main pole magnet slot 312 into which the main pole magnet 322 is inserted, a d-axis core portion 311a disposed on the stator 2 side relative to the main pole magnet slot 312, and a back yoke 311b disposed on the side opposite to the d-axis core portion 311a relative to the main pole magnet slot 312.

[0055] The back yoke 311b of the split core 311 has a split core-side conical portion 311b1, which has a conical surface 311b2 whose circumferential width increases toward the housing 33 side (inner circumferential side in this embodiment). The back yoke 311b as a whole constitutes the split core-side conical portion 311b1, and the two circumferential sides of the back yoke 311b are formed by conical surfaces 332b.

[0056] The segmented core 311 has a main pole magnet slot 312. The main pole magnet slot 312 is composed of a single segmented core 311. More specifically, a bridge portion 311c is provided between the main pole magnet slot 312 and the spoke magnet slot 313. The main pole magnet slot 312 is composed of two bridge portions 211c arranged on both sides of the main pole magnet 321 in the circumferential direction, a d-axis core 211a, and a back yoke 311b.

[0057] In contrast, the spoke magnet groove 313 for accommodating the spoke magnet 322 is formed by at least two adjacent split cores 311 and the protruding portion 332 of the housing 33. More specifically, the spoke magnet groove 313 is formed by two bridge portions 311c, two back yokes 311b of two adjacent split cores 311, and the protruding portion 332 of the housing 33. In this case, the spoke magnet groove 313 preferably includes two d-axis core portions 311a of two adjacent split cores 311. That is, the spoke magnet groove 313 is formed in the radial direction to span the range of the two bridge portions 311c and the d-axis core portions.

[0058] The d-axis core portion has a d-axis core protruding portion 311e protruding in the circumferential direction at the end portion 311d on the stator 2 side in the radial direction. The d-axis core protruding portions 311e are provided to be separated from the d-axis core protruding portions 311e of the adjacent split cores 311.

[0059] The back yoke 311b of the split core 311 constitutes a magnetic path for guiding the magnetic flux of the main pole magnet 321 to the adjacent spoke magnet 322. If the radial width of the back yoke 311b is L1, the circumferential width of the bridge portion 311c is L2, and the radial width of the bridge portion 311c is L3, then L1, L2, and L3 preferably have a relationship of L2 < L1 < L3.

[0060] The tapered surfaces 311b2 forming the circumferential both side surfaces of the back yoke 311b are located at positions protruding in the circumferential direction with respect to the bridge portion 311c. The back yoke 311b is configured such that the tapered surfaces 311b2 provided on two adjacent split cores 311 are located at positions separated in the circumferential direction. Moreover, the split core 311 and the housing 33 are fastened such that the protruding portion 332 of the housing 33 is interposed between two adjacent tapered surfaces 311b2.

[0061] The split core 311 and the housing 33 are joined by a dovetail groove structure formed by the back yoke 311b and two protruding portions 332 adjacent to the back yoke 311b. That is, the split core 311 and the housing 33 are joined by crimping the tapered surface 311b2 of the split core side tapered portion 311b1 and the tapered surface 332b of the housing side tapered portion 332a.

[0062] As described above, the rotor 3 of the rotating electric machine of this embodiment has the following characteristics.

[0063] (1) It includes a magnet 32, a rotor core 31 into which the magnet 32 is inserted, and a housing 33 for fixing the rotor core 31.

[0064] The magnet 32 is composed of a main pole magnet 321 whose magnetization direction is toward the radial direction and a spoke magnet 322 whose magnetization direction is toward the circumferential direction.

[0065] The rotor core 31 is composed of an aggregate of split cores 311.

[0066] The segmented core 311 includes a main pole magnet slot 312 into which the main pole magnet 321 is inserted, a d-axis core portion 311a disposed on the stator 2 side relative to the main pole magnet slot 312, and a back yoke 311b disposed on the side opposite to the d-axis core portion 311a relative to the main pole magnet slot 312.

[0067] In the rotor 3 of the rotating electric motor 1,

[0068] The housing 33 has a protrusion 332 that protrudes radially inward.

[0069] The housing 33, including the protrusion 332, is made of a non-magnetic material.

[0070] The two adjacent segmented iron cores 311 and the protrusions 332 constitute the spoke magnet slots 313 for housing the spoke magnets 332.

[0071] The core 311 and the shell 33 are joined by a dovetail groove structure formed by the back yoke 311b and two protrusions 332 adjacent to the back yoke 311b.

[0072] exist Figure 3 In the middle, the circumferential side 311b2 of the back yoke 311b also serves as a dovetail groove structure for fixing the split core 311 to the housing 33. Using Figure 4 This section explains the effect of the dovetail groove structure in this embodiment. Figure 4 This is a diagram illustrating the subject matter of a rotor compared to the present invention.

[0073] exist Figure 4 In the comparative example, a back yoke 311b' is also provided on the side opposite to the stator 2 (the anti-gap side) relative to the spoke magnet 322. This back yoke 311b' forms a magnetic circuit that short-circuits the N and S poles of the spoke magnet, and leakage flux Φ2 flows between the N and S poles. Therefore, the back yoke 311b' on the anti-gap side of the spoke magnet may become a major factor hindering torque increase. That is, the back yoke 311b' is an unnecessary part of torque generation.

[0074] In this embodiment, by removing the back yoke 311b', the magnetic circuit portion where leakage flux Φ2 flows is eliminated, improving the magnetic characteristics of the rotor core 31 and thus increasing the torque generated by the rotary motor 1. Furthermore, removing the back yoke 311b' makes the rotor core 31 lighter, increasing the output density of the rotary motor 1. Additionally, when a structure for realizing a dovetail groove structure is added to the segmented core 311, the mass of the segmented core 311 increases, and the output density of the rotary motor 1 decreases. In this embodiment, by utilizing a portion of the back yoke 311b' as a dovetail groove structure, it is unnecessary to add a structure for realizing a dovetail groove structure to the segmented core 311, and the output density of the rotary motor 1 is not reduced. Therefore, the trade-off between the robust fixation of the segmented core 311 and the housing 33 and the output density of the rotary motor 1 in the conventional structure is eliminated, thereby increasing the output density of the rotary motor 1.

[0075] (2) The back yoke 311b forms a magnetic circuit that guides the magnetic flux Φ1 of the main pole magnet 321 to the adjacent spoke magnet 322. In this embodiment, the magnetic flux Φ1 that generates torque flows as follows.

[0076] d-axis core 311a of S pole → main pole magnet of S pole 321 → back yoke 311b → bridge 311c → spoke magnet 322 → bridge 311c → back yoke 311b → main pole magnet of N pole 321 → d-axis core 311a of N pole

[0077] In such a magnetic circuit, in order not to impede the flow of magnetic flux Φ1, the dimensional relationship between the back yoke 311b and the bridge 311c needs to be set appropriately. This will be described later.

[0078] (3) The protrusion 332 of the housing 33 has a housing side cone 332a, which has a tapered surface 332b whose width increases circumferentially as it faces the split core 311 side.

[0079] The back yoke 311b of the split core 311 has a split core side cone 311b1, which has a tapered surface 311b2 whose width increases circumferentially toward the housing 33 side.

[0080] The split core 311 and the shell 33 are joined together by pressing the conical surface 311b2 of the split core side cone 311b1 and the conical surface 332b of the shell side cone 332a.

[0081] This achieves the dovetail groove structure.

[0082] (4) A bridge portion 311c is provided between the main pole magnet slot 312 and the spoke magnet slot 313.

[0083] The main pole magnet slot 312 is composed of two bridge portions 311c and d, an axial core portion 311a, and a back yoke portion 311b that are arranged on both circumferential sides with respect to the main pole magnet 321.

[0084] The spoke magnet slot 313 is composed of two bridge portions 311c of two adjacent split cores 311, two back yokes 311b, and a protruding portion 332 of the housing 33.

[0085] (5) The spoke magnet slot 313 is composed of two d-axis core portions 311a of two adjacent split cores 311.

[0086] (6) The d-axis core portion 311a has a d-axis core protruding portion 311e that protrudes circumferentially at an end portion 311d on the stator 2 side in the radial direction.

[0087] The d-axis core protruding portion 311e is arranged to be separated from the d-axis core protruding portion 311e of the adjacent split core 311.

[0088] By having the d-axis core protruding portion 311e, it is possible to prevent the spoke magnet 322 from flying out toward the stator 2 side due to centrifugal force or magnetic attraction force. As a result, the robustness of the rotor 3 is improved. In addition, by separating the d-axis core protruding portions 311e of two adjacent split cores 311, it is possible to reduce the leakage magnetic flux short-circuited through the d-axis core protruding portion 311e, thereby improving the torque of the rotating electrical machine 1.

[0089] (7) If the radial width of the back yoke 311b is L1, the circumferential width of the bridge portion 311c is L2, and the radial width of the bridge portion 311c is L3, then L2 < L1 < L3.

[0090] The magnetic flux flowing from the spoke magnet 322 to the back yoke 311b (or from the back yoke 311b to the spoke magnet 322) is determined by the dimensional relationship of L1 to L3. If L1 is less than L2 (L1 < L2), the back yoke 311b is magnetically saturated and the magnetic flux of the main pole magnet cannot be effectively utilized. Therefore, by setting L2 < L1, it is possible to seek an increase in torque.

[0091] In addition, the maximum magnetic flux flowing into the back yoke 311b is not more than the product of the magnetic flux density in the spoke magnet 322, L3, and the stack thickness. Since the magnetic flux density in the magnet generally does not exceed 2 T (tesla), even if L1 is less than L3 (L1 < L3), the rotating electrical machine 1 can be driven within the range where the back yoke 311b does not become magnetically saturated. On the other hand, when L1 > L3, the increase in torque is small with respect to the increase in the radial width of the back yoke 311b, so the torque density decreases.

[0092] As described above, by setting L2 < L1 < L3, it is possible to increase the torque density of the rotating electrical machine 1 and increase the output density.

[0093] [Example of Change 1]

[0094] use Figure 5 A modification example (first modification example) of the rotor core 31 will be described. Figure 5 It means Figure 3 An enlarged top view of a modified example (first modified example) of the split core 311.

[0095] In this example, the housing 33 has a recess (resin molding hole) 51 on its outer peripheral surface 33a, which is opposite to the back yoke 311b of the split core 311. Resin 52 is molded into the recess 51.

[0096] When the housing 33 and the segmented core 311 are assembled, the recess 51 becomes an axially extending hole. By molding resin 52 into this hole 51, the gap between the segmented core 311 and the housing 33 can be filled with the resin 52. As a result, since the segmented core 311 is fixed to the housing 33 without gaps through resin molding, the robustness of the rotor 3 is improved. Furthermore, since the segmented core 311 does not wobble relative to the housing 33, vibration and noise can be suppressed.

[0097] Furthermore, even if the tolerance of the segmented core 311 is taken into account beforehand and the segmented core 311 and the housing 33 are loosely fastened (in the case of large gaps), the segmented core 311 can be fixed relative to the housing 33 using the molded resin 52. As a result, mass production capability is improved.

[0098] (8) As described above, in the rotor 3 of this example, the housing 33 has a recess 51 on the outer peripheral surface 33a opposite to the back yoke 311b of the split core 311, which is recessed to the inner peripheral side. The recess is molded from resin 52.

[0099] [Example of Amendment 2]

[0100] use Figure 6A A modified example of rotor core 31 (the second modified example) will be described. Figure 6A It means Figure 3 An enlarged top view of a modified example (second modified example) of the segmented iron core 311.

[0101] In this example, the housing 33 has a recess (pin insertion hole) 53 on its outer peripheral surface 33a, which is recessed inward on the outer peripheral side, opposite to the back yoke 311b of the split core 311. The pin 54 is inserted into the recess 53. Compared with the first modified example, the resin 52 is replaced by the pin 54, and the fixing of the split core 311 relative to the housing 33 can also be achieved by the pin 54.

[0102] (9) That is, in the rotor 3 of this example, the housing 33 has a recess 53 on the outer peripheral surface 33a opposite to the back yoke 311b of the split iron core 311, which is recessed to the inner peripheral side, and a pin 54 is inserted into the recess 53.

[0103] Therefore, even if the split core 311 is clearance-fitted relative to the housing 33, the split core 311 will still be subjected to a radially pushing force relative to the housing 33 due to the pin 54. As a result, the conical surfaces 311b2 of the two circumferential sides of the back yoke 311b constituting the split core 311 contact the conical surfaces 332b of the circumferential protrusions 332 of the housing 33, and the split core 311 is fixed relative to the housing 33 without wobbling. Therefore, the robustness of the rotor 3 is improved, and vibration and noise can be suppressed.

[0104] Figure 6B express Figure 6A A partially enlarged view of the conical surfaces of the split core 311 and the housing 33. With the split core 311 and housing 33 in a clearance fit, and the cone angle set as θ, and the circumferential dimensional difference (clearance) between the split core 311 and housing 33 set as Δc (half of Δc on one side), the radial clearance between the split core 311 and housing 33 is:

[0105] Δc / 2×(1 / tan θ)

[0106] That is, when θ is greater than tan^-1(0.5)≈26.56, the radial clearance is less than or equal to the circumferential clearance. Since the radial (caused by the clearance) dimensional deviation of the segmented core 311 is the deviation of the gap length between the stator 2 and the rotor 3, it is preferable to be smaller. Therefore, by adopting the configuration of this example and setting θ≥26.56, the deviation of the gap length can be reduced, the characteristics of the rotary motor 1 can be stabilized, and mass production capability can be improved.

[0107] [Example 3 of the amendment]

[0108] use Figure 7 A modification example (the third modification example) of the rotor core 31 will be described. Figure 7 It means Figure 3 An enlarged top view of a modified example of a split iron core (the third modified example).

[0109] In this example, the housing 33 has a recess (yoke receiving portion) 333 between the two protrusions to accommodate the back yoke 311b. The bottom surface 333a of the recess 333 is located between the two protrusions 332 and is formed by the outer peripheral surface 33a of the housing 33, which is opposite to the inner peripheral side surface 311f of the back yoke 311b. The recess 333 is configured to form a gap δ between the bottom surface 333a and the inner peripheral side surface 311f of the back yoke 311b. That is, the outer peripheral surface 33a of the housing 33 is separated from the inner peripheral side surface 311f of the back yoke 311b without contact.

[0110] When the segmented core 311 is divided along the q-axis, the back yoke 311b of the segmented core 311 protrudes circumferentially symmetrically. In this case, the elastic force of the back yoke 311b, when the segmented core 311 is fixed and supported on the housing 33, acts equally circumferentially on the segmented core 311. Therefore, the stress generated on the protrusions 332 is equally distributed to the two protrusions 332, improving the mechanical strength reliability of the protrusions 322. In this structure, the gap δ is a clearance hole for the thermal expansion of the segmented core 311. This allows for a more secure fixation and support of the segmented core 311.

[0111] (10) That is, in rotor 3 in this example,

[0112] The housing 33 has a recess 333 between the two protrusions to accommodate the back yoke 311b.

[0113] The bottom surface 333a of the recess 333 is located between the two protrusions 332 and is formed by the outer peripheral surface 33a of the shell 33, which is opposite to the inner peripheral side surface 311f of the back yoke 311b.

[0114] The recess 333 is configured to form a gap δ between the bottom surface 333a and the inner peripheral side surface 311f of the back yoke 311b.

[0115] [Amendment Example 4]

[0116] use Figure 7 A modification example (the fourth modification example) of the rotor core 31 will be described.

[0117] In this example, the housing 33 has a recess (yoke receiving portion) 333 between the two protrusions to accommodate the back yoke 311b. The bottom surface 333a of the recess 333 is located between the two protrusions 332 and is formed by the outer peripheral surface 33a of the housing 33, which is opposite to the inner peripheral side surface 311f of the back yoke 311b. The recess 333 is configured to form a gap δ between the bottom surface 333a and the inner peripheral side surface 311f of the back yoke 311b. That is, the outer peripheral surface 33a of the housing 33 is separated from the inner peripheral side surface 311f of the back yoke 311b without contact.

[0118] Therefore, the split core 311 can be easily inserted into the housing 33 from the axial direction, improving assemblability. An adhesive or foam material (not shown) is contained in the gap δ.

[0119] Adhesives or foaming materials can fill part of the space formed by the gap δ, or they can fill all of the space.

[0120] By incorporating adhesive within the gap δ, the segmented core 311 is bonded and fixed to the housing 33, thus improving the robustness of the rotor 3. Furthermore, since the segmented core 311 does not wobble relative to the housing 33, vibration and noise can be suppressed.

[0121] Similarly, by accommodating foamed material in the gap δ, and by foaming the material after assembling the housing 33 and the segmented core 311, the segmented core 311 is subjected to a radially pushing force relative to the housing 33. As a result, the conical surfaces 311b2 of the two circumferential sides of the back yoke 311b constituting the segmented core 311 contact the conical surfaces 332b of the circumferential protrusions 332 of the housing 33, and the segmented core 311 is fixed relative to the housing 33 without wobbling. Therefore, the robustness of the rotor 3 is improved, and vibration and noise can be suppressed.

[0122] When the segmented core 311 is in clearance fit with the housing 33, if the cone angle is set to θ and the circumferential dimensional difference (clearance) between the segmented core 311 and the housing 33 is set to Δc (half of Δc on one side), then the radial clearance between the segmented core 311 and the housing 33 is:

[0123] Δc / 2×(1 / tanθ)

[0124] That is, when θ is greater than tan^-1(0.5)≈26.56, the radial clearance is less than or equal to the circumferential clearance. Since the radial (caused by the clearance) dimensional deviation of the segmented core 311 is the deviation of the gap length between the stator 2 and the rotor 3, it is preferable to be smaller. Therefore, by adopting the configuration of this example and setting θ≥26.56, the deviation of the gap length can be reduced, the characteristics of the rotary motor 1 can be stabilized, and mass production capability can be improved.

[0125] [other]

[0126] The rotor 3 in this embodiment and its modified version can improve the output density when applied to a rotating electric motor.

[0127] (11) That is, in a rotating electric motor having a rotor and a stator opposite to the rotor with a predetermined gap, the rotor 3 of this embodiment and the modified embodiment can be used as the rotor.

[0128] [Combination with fractional slot concentrated winding]

[0129] use Figure 8 and Figure 9 This embodiment describes the combination of rotor 3 and fractional slot concentrated winding. Figure 8 This is a top view showing a portion of the rotor 3 and stator 2 when the rotor 3 of the present invention is used to form a fractional slot concentrated winding rotary motor 1. Figure 9 This diagram illustrates the advantages of using the rotor 3 of the present invention to construct a rotary motor 1 with fractional-slot concentrated windings. Furthermore, in Figure 8 and Figure 9 In the diagram, only coil 213, which is in phase, is shown.

[0130] In the aforementioned rotary motor 1, it is preferable to divide the number of slots of the stator 2 by the number of phases of the coil 213 and the number of poles of the rotor 3, i.e., a fractional slot with a fractional number of slots per pole per phase. In this case, the coil 213 inserted into the slots of the stator 2 can be a fractional slot concentrated winding, which forms a rotating magnetic field by the continuous crossing of at least two adjacent slots by coils 213 of the same phase.

[0131] In the case of fractional-slot concentrated windings, the position (phase) of the stator teeth opposite a pole of a rotor is different from the position (phase) of the teeth opposite the adjacent poles. That is, for example, the distribution of magnetic flux from a certain N pole to the adjacent S pole is different from the distribution of magnetic flux from that S pole to the adjacent N pole. In particular, in fractional-slot concentrated windings, when multiple in-phase coils 213 that continuously cross adjacent slots are regarded as a single coil group, magnetic flux caused by the current flowing through these two coil groups is also generated between two adjacent coil groups. Therefore, when the rotor core 31 is not divided and the back yoke 311b of the rotor 3 is connected as a whole, due to the asymmetry of the magnetic flux distribution of each pole as described above, magnetic flux crossing multiple poles flows in the back yoke 311b.

[0132] The magnetic flux flowing through the multiple poles in the back yoke 311b is different from the magnetic flux that acts on torque. It is a magnetic flux that generates torque pulsation and only increases the iron loss of the back yoke 311b of the rotor 3.

[0133] In this embodiment, by constructing the rotor core 31 from the segmented core 311, the magnetic resistance to the magnetic flux flowing in the back yoke 311A2 across the multiple poles can be increased by the segmented portion 311j, thereby reducing the magnetic flux Φ3.

[0134] As described above, since the segmented portion 311j of this embodiment is independent of the magnetic circuit of the main magnetic flux, by applying the segmented core 311 of this embodiment to the fractional-slot concentrated winding, the basic performance of the rotary motor 1, such as torque and output, is not reduced. Torque pulsation caused by the magnetic flux Φ3 flowing through multiple poles in the back yoke 311A2 and iron losses generated in the back yoke 311A2 of the rotor 3 can be reduced. Therefore, the quietness of the rotary motor 1 can be improved, and the efficiency of the rotary motor 1 can be increased.

[0135] (12) That is, in this example, the number of slots 214 of the stator 2 is the number of phases of the coil and the number of poles of the rotor 3, that is, the number of slots per pole and per phase is a fraction of the number of slots.

[0136] The coil 213 inserted into slot 214 is a fractional slot concentrated winding, which forms a rotating magnetic field by the continuous crossing of at least two adjacent slots 214 by coils 213 of the same phase.

[0137] [Vehicle Example]

[0138] use Figure 10 An embodiment of mounting the rotary motor 1 of the present invention on a vehicle (xEV) is described. Figure 10 This is a diagram showing the configuration of the xEV100 of a rotary motor 1 employing an embodiment of the present invention.

[0139] The rotary motor 1, which serves as the drive motor, is fixedly supported on the trolley 101 by a support member 102. The rotor of the rotary motor 1 is connected to the axle 106, and the rotary motor 1 drives the wheels 103 via the axle 106. The vehicle 100 includes the rotary motor 1, a battery 105, and a power conversion device 107 that converts the DC power from the battery 105 into AC power and supplies the AC power to the rotary motor 1.

[0140] In this embodiment of the xEV, by incorporating the rotary motor 1 of this embodiment, it is possible to increase the slot occupancy rate of the coil 11, reduce losses, and simplify the coil heat dissipation structure, thereby achieving high output density of the drive motor. This results in high torque and provides an xEV with excellent cost-effectiveness.

[0141] (13) The vehicle 100 in this example includes: a rotary motor, a battery 105, and a power conversion device 107 that converts the DC power of the battery 105 into AC power and supplies the AC power to the rotary motor 1.

[0142] In this vehicle, the rotor 3 of the rotary motor 1 described in the above embodiments and modifications is used as the rotary motor.

[0143] Furthermore, the present invention is not limited to the embodiments described above, but includes various modifications. For example, the above embodiments are detailed descriptions provided for ease of understanding of the present invention and are not necessarily limited to having all the configurations. In addition, for a part of the configuration of the embodiments, other configurations may be added, deleted, or replaced.

[0144] Explanation of symbols

[0145] 1… Rotary motor, 2… Stator, 3… Rotor, 31… Rotor core, 32… Magnet, 33… Housing, 33a… Outer peripheral surface of housing 33, 51… Recess, 52… Resin, 53… Recess, 54… Pin, 100… Vehicle, 105… Battery, 107… Power conversion device, 213… Coil, 214… Slot of stator 2, 311… Segmented core, 311a… D-axis core portion, 311b… Back yoke, 311b1… Segmented core side cone, 311b2… Conical surface of segmented core side cone 311b1, 311c… Bridge portion, 311d… D-axis core portion 31 located radially on the side of stator 2 1a end, 311e… d-axis iron core protrusion protruding circumferentially, 311f… inner circumferential side of back yoke 311b, 312… main pole magnet slot, 313… spoke magnet slot, 321… main pole magnet, 322… spoke magnet, 332… protrusion, 332a… shell side cone, 332b… cone surface of shell side cone 332a, 333… recess accommodating back yoke 311b, 333a… bottom surface of recess 333, L1… radial width of back yoke 311b, L2… circumferential width of bridge 311c, L3… radial width of bridge 311c, δ… gap, Φ1… magnetic flux of main pole magnet 321.

Claims

1. A rotor of a rotary electric machine, comprising: a magnet, a rotor core into which the magnet is inserted, a housing that fixes the rotor core, the magnet is composed of a main pole magnet whose magnetization direction is directed in a radial direction and a spoke magnet whose magnetization direction is directed in a circumferential direction, the rotor core is composed of an assembly of divided cores, the divided core includes a main pole magnet slot into which the main pole magnet is inserted, a d-axis core portion disposed on a stator side with respect to the main pole magnet slot, and a back yoke disposed on a side opposite to the d-axis core portion with respect to the main pole magnet slot, the rotor of the rotary electric machine is characterized in that: the housing includes a protruding portion that protrudes toward the divided core, the housing including the protruding portion is composed of a non-magnetic material, two adjacent divided cores and the protruding portion constitute a spoke magnet slot that accommodates the spoke magnet, and the divided core and the housing are joined by a dovetail groove structure constituted by the back yoke and two adjacent protruding portions of the housing.

2. The rotor of the rotary electric machine according to claim 1, wherein the back yoke constitutes a magnetic circuit that guides a magnetic flux of the main pole magnet to the adjacent spoke magnet.

3. The rotor of the rotary electric machine according to claim 1, wherein the protruding portion of the housing has a housing-side tapered portion having a tapered surface whose width in the circumferential direction increases toward the divided core side, the back yoke of the divided core has a divided core-side tapered portion having a tapered surface whose width in the circumferential direction increases toward the housing side, and the divided core and the housing are joined by crimping the tapered surfaces of the divided core-side tapered portion and the housing-side tapered portion.

4. The rotor of the rotary electric machine according to claim 2, wherein a bridge portion is provided between the main pole magnet slot and the spoke magnet slot, the main pole magnet slot is constituted by two bridge portions disposed on both sides in the circumferential direction with respect to the main pole magnet, the d-axis core portion, and the back yoke, and the spoke magnet slot is constituted by two bridge portions and two back yokes of two adjacent divided cores and the protruding portion of the housing.

5. The rotor of the rotary electric machine according to claim 4, wherein the spoke magnet slot is constituted by two d-axis core portions of two adjacent divided cores.

6. The rotor of the rotary electric machine according to claim 5, wherein the d-axis core portion has a d-axis core protruding portion that protrudes in the circumferential direction at an end portion on the stator side in the radial direction, and the d-axis core protruding portion is provided so as to be separated from a d-axis core protruding portion of an adjacent divided core.

7. The rotor of the rotary electric machine according to claim 4, wherein a radial width of the back yoke is set to Ll, a circumferential width of the bridge portion is set to L2, and a radial width of the bridge portion is set to L3, and L2 < Ll < L3.

8. The rotor of the rotary electric machine according to claim 1, wherein the housing is provided with a recess that is recessed toward an inner peripheral side on an outer peripheral surface opposite to the back yoke of the divided core, and a resin is molded in the recess. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. The rotor of a rotary electric machine according to claim 1, characterized in that, the housing is provided with a recess that is recessed toward the inner peripheral side on an outer peripheral surface opposite the back yoke of the divided core, a pin is inserted in the recess.

10. The rotor of a rotary electric machine according to claim 1, characterized in that, the housing has a recess portion that accommodates the back yoke between the two protruding portions, a bottom surface of the recess portion being located between the two protruding portions and being constituted by an outer peripheral surface of the housing opposite the inner peripheral surface of the back yoke, the recess portion is configured to form a gap between the bottom surface and the inner peripheral surface of the back yoke.

11. The rotor of a rotary electric machine according to claim 10, characterized in that, an adhesive or a foamed material that generates a force that pushes the back yoke in the radial direction is accommodated in the gap.

12. A rotary electric machine, comprising: a rotor and a stator that opposes the rotor across a prescribed gap, the rotary electric machine being characterized in that, the rotor of claim 1 is provided as the rotor.

13. The rotary electric machine according to claim 12, characterized in that, the number of slots of the stator divided by the number of phases of the coils and the number of poles of the rotor is a fractional number, i.e., the number of slots per pole per phase is a fractional number, the coil inserted into the slot is a fractional-slot concentrated winding that constitutes a rotating magnetic field by continuously spanning at least two or more adjacent slots with coils of the same phase.

14. A vehicle, comprising: a rotary electric machine, a battery, a power conversion device that converts direct-current electric power of the battery into alternating-current electric power and supplies the alternating-current electric power to the rotary electric machine, the vehicle being characterized in that, the rotary electric machine includes the rotor of a rotary electric machine of claim 1.

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