Rotary electric machine

Abstract

To provide a fixing structure in which a magnetic characteristic is prevented from being deteriorated and which can firmly fix a split core to a support member.SOLUTION: A rotor core 31 is constituted of: an aggregate of a plurality of split cores 311 split in a circumferential direction; and a non-magnetic rotor housing 33 to which the split cores 311 are fastened. The split core 311 has split parts 311j with adjacent split cores 311 at portions of back yokes 311A2 constituting a slot 311d of a spoke magnet 322, and has a fastening part 311e to the rotor housing 33 between the two split parts 311j provided between the adjacent split cores 311. The two split parts 311j constitute projection parts 311k projected in opposite directions in the circumferential direction. The split core 311 is fastened to the rotor housing 33 so that the fastening part 311e and the projection parts 311k receive force in the opposite directions in the radial direction.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] Patent Document 1 describes an electric motor having a rotor, a stator, a stator core that constitutes the stator, a core portion that constitutes the stator core, a number of split core blocks that constitute the core portion, and a metallic connecting housing that connects the split core blocks by dovetail connections to form a single connected core portion, in which the split core blocks are formed from laminated steel plates and the connecting housing is formed from a material softer than the laminated steel plates, and the dovetail connection portion on the connecting housing side is plastically deformed so that the connection gap that exists at the dovetail connection is filled and eliminated (see abstract). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-169431 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the electric motor of Patent Document 1, a technique is proposed in which the dovetail joint portion on the connecting housing side is plastically deformed to fill the joint gap (clearance) present at the dovetail joint portion. This technique can eliminate the clearance at the dovetail joint portion, but since it involves plastic deformation, there is a risk of a decrease in the elastic modulus and member strength of the plastically deformed portion. In this case, even though the clearance is filled to reduce vibration and noise of the split core block, the plastically deformed portion is easily deformed, so the split core block is still in a state where it is easily vibrated.

[0005] In addition, regardless of whether the deformation is plastic or elastic, when the region through which the main magnetic flux that contributes to the characteristics of the rotating electric machine passes is deformed, it is known that the magnetic characteristics deteriorate according to the stress and displacement caused by the deformation, which may lead to a decrease in torque and an increase in iron loss. When the split core blocks are fixed to the connecting housing by plastic or elastic deformation, in a configuration in which a plastically deformed portion or an elastically deformed portion is formed in the region through which the main magnetic flux passes, there is a trade-off between the vibration suppression of the split core blocks and the magnetic characteristics of the rotating electric machine.

[0006] In the following description, the "split core blocks" will be referred to as "split cores" and the "connecting housing" will be referred to as the "support member."

[0007] An object of the present invention is to provide a fixing structure that can firmly fix a split core to a support member without deteriorating magnetic properties. [Means for solving the problem]

[0008] In order to achieve the above object, a rotating electric machine according to the present invention comprises: a rotor having a magnet and a rotor core into which the magnet is inserted; a stator facing the rotor with a predetermined gap therebetween, the magnet is composed of a main pole magnet, the magnetization direction of which faces a radial direction of the rotating electric machine, and a spoke magnet, the magnetization direction of which faces a circumferential direction of the rotating electric machine; the rotor core is composed of an assembly of a plurality of split cores divided in a circumferential direction, and a non-magnetic rotor housing to which the split cores are fastened; the split core has a split portion between adjacent split cores at a portion of a back yoke that defines a slot of the spoke magnet, and has a fastening portion to the rotor housing between two split portions provided between adjacent split cores, Each of the two divided portions constitutes a protruding portion protruding in an opposite direction in the circumferential direction, The split core is fastened to the rotor housing such that the fastening portion and the protruding portion receive forces in opposite directions in the radial direction.

[0009] In order to achieve the above object, a rotating electric machine according to the present invention comprises: a rotor including a magnet and a rotor core into which the magnet is inserted; a stator facing the rotor with a predetermined gap therebetween, the magnet is composed of a main pole magnet, the magnetization direction of which faces a radial direction of the rotating electric machine, and a spoke magnet, the magnetization direction of which faces a circumferential direction of the rotating electric machine; the rotor core is composed of an assembly of a plurality of split cores divided in a circumferential direction, and a non-magnetic rotor housing to which the split cores are fastened; The split core has a split portion between adjacent split cores at a portion of a back yoke that constitutes a slot of the main pole magnet, and has a fastening portion to the rotor housing between two split portions provided between adjacent split cores, Each of the two divided portions constitutes a protruding portion protruding in an opposite direction in the circumferential direction, The split core is fastened to the rotor housing such that the fastening portion and the protruding portion receive forces in opposite directions in the radial direction. Effect of the Invention

[0010] According to the present invention, it is possible to provide a fixing structure that is unlikely to affect magnetic properties and can firmly fix a split core to a support member. Problems, configurations and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief description of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view of a rotating electric machine according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view of a rotor according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view showing the cross section III-III of FIG. 2. [Figure 4] 3 is a perspective view of the rotor 3 shown in FIG. 2 with a pressing plate 34 removed. [Diagram 5] 4 is a plan view showing a state in which a plurality of split cores are arranged in the circumferential direction. FIG. [Figure 6] FIG. 1 is a perspective view showing a single split core according to an embodiment (first embodiment) of the present invention. [Figure 7] 7 is an enlarged plan view of part VII of the rotor core in FIG. 4. [Figure 8] 8 is an enlarged view of a portion VIII of the partial cross section of FIG. 7, and is a plan view showing vectors of forces acting on the split cores. FIG. [Figure 9] FIG. 9 is a magnetic flux diagram showing a typical main magnetic flux in the split core of FIG. 8. [Figure 10] 7 is a perspective view showing a modification (first modification) of the split core in FIG. 6. FIG. [Figure 11] 7 is a perspective view showing another modification (second modification) of the split core in FIG. 6. FIG. [Figure 12] FIG. 11 is a plan view showing a configuration of a split core according to an embodiment (second embodiment) of the present invention. [Figure 13] FIG. 11 is a perspective view showing a single split core according to an embodiment (second embodiment) of the present invention. [Figure 14] 14 is a perspective view showing a modification (first modification) of the split core in FIG. 13. FIG. [Figure 15] 14 is a perspective view showing another modification (second modification) of the split core in FIG. [Figure 16] 14 is a perspective view showing another modification (third modification) of the split core in FIG. [Figure 17] 13 is an enlarged plan view of the rotor core 31 of the first embodiment to which a third modified example is applied. FIG. [Figure 18] 1 is a diagram showing the configuration of an xEV that employs a rotating electric machine according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present invention will be described. In each embodiment and each drawing, the same reference numerals are used for similar components to avoid duplication of explanation. In addition, when there are differences between components that are given the same reference numerals, the differences will be explained.

[0013] [Example 1] A rotating electric machine 1 according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is an exploded perspective view of the rotating electric machine 1 according to an embodiment of the present invention.

[0014] The rotating electric machine 1 includes, as its main components, a stator 2, a rotor 3, an end bracket 4, and a power conversion device 5. The stator 2 has a stator core 21, and the rotor 3 has a rotor core 31. In this embodiment, the stator 2 and the 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 the rotor 3 are arranged so as not to contact each other, and a gap (air gap) is provided between the stator 2 and the rotor 3.

[0015] The rotating electric machine 1 of this embodiment has an inner rotor structure in which the rotor 3 is disposed on the inner periphery of the stator core 21, but may have an outer rotor structure in which the rotor 3 is disposed on the outer periphery of the stator core 21.

[0016] The stator 2 is composed of a stator core 21 formed by laminating a plurality of core sheets and a coil wound around the stator core 21. The stator core 21 has a circular stator back yoke 211, a plurality of teeth 212 connected to the stator back yoke 211 and provided on the radial gap side, and slots formed between the teeth. The stator core 21 may be composed of an integrally molded solid member. It may also be composed of a powder magnetic material such as a dust core that has been compression molded, or may be composed of an amorphous metal or a nanocrystalline material.

[0017] Coils 213 are wound around teeth 212 and slots. Coils 213 are made up of in-slot coils inserted into the slots, coil ends that span between slots at different positions, and leads for inputting current from an external circuit and connecting coils at different positions. Coils 213 are arranged with U-phase, V-phase, and W-phase coils, for example, to generate a rotating magnetic field in the gap. The phases of the input fundamental wave components of the current differ by 120° between the three phase coils, which generates a rotating magnetic field in the gap. Rotor 3 is driven to rotate by this rotating magnetic field.

[0018] The power conversion device 5 performs a switching operation to convert DC power supplied from a battery or a DC power supply (not shown) into three-phase AC power. This three-phase AC power is supplied to a stator winding (not shown) of the stator 2, and a rotating magnetic field is generated in the stator 2.

[0019] Although not shown in Fig. 1, the rotor 3 is provided with a rotating shaft. The dashed line 1a in Fig. 1 represents the axis of the rotating shaft and its extension line. In other words, the dashed line 1a coincides with the rotation axis of the rotor 3, which includes the rotating shaft. The rotor 3 and the stator 2 share the same central axis, and the central axis of the rotor 3 coincides with the rotation axis 1a.

[0020] A rotor 3 according to an embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a perspective view of a rotor 3 according to an embodiment of the present invention.

[0021] In the following description, the "radial direction DR," "circumferential direction Dθ," and "axial direction DZ" are defined as follows. The "radial direction DR" is a linear direction that intersects perpendicularly with the rotation axis 1a. The "circumferential direction Dθ" is the direction of rotation around the rotation axis 1a. The "axial direction DZ" is a linear direction that is parallel to the rotation axis 1a. Additionally, the "inner circumference side" and "outer circumference side" are defined as the side closer to the rotation axis 1a as the "inner circumference side," and the side farther away as the "outer circumference side."

[0022] The rotor 3 has a rotor core 31 composed of an assembly of multiple split cores 311, a magnetic pole portion 32 (see Figure 4) provided on the rotor core 31, a housing 33 to which the multiple split cores 311 are fastened, and a pressing plate 34 facing one end face 311a of the split core 311 in the axial direction DZ and pressing the split core 311 against the housing 33.

[0023] The rotor 3 rotates around the rotation axis 1a. A rotating shaft (not shown) may be fixed to the rotor 3, and the rotating electric machine 1 may include a frame that covers the stator 2 and the rotor 3. The rotor 3 is connected to a load directly or via a structural member such as a rotating shaft or a frame, and transmits rotation and torque to the load as the rotor 3 rotates.

[0024] The rotor core 31 is formed by laminating a plurality of core sheets. The rotor core 31 may be formed of an integrally molded solid member. The rotor core 31 may also be formed by compression molding a powder magnetic material such as a dust core, or may be formed of an amorphous metal or a nanocrystalline material.

[0025] The fastening structure of the split core 311 will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view showing the III-III cross section of Fig. 2.

[0026] The housing 33 is a member formed of a non-magnetic material. The housing 33 has a cylindrical portion 33 extending in the axial direction DZ, a flange portion 332 extending radially outward from the cylindrical portion 33, and a hole portion 333 formed in the flange portion 332. The hole portion 333 extends from an end surface 332a of the flange portion 332 in the axial direction DZ.

[0027] A magnet insertion hole (main pole magnet insertion hole) 311c is formed in the split core 311, and the main pole magnet 321 is inserted into the main pole magnet insertion hole 311c. The main pole magnet insertion hole 311c constitutes a part of the magnetic pole portion 32 (see FIG. 4).

[0028] Split core 311 is disposed such that the other end face 311b abuts against end face 332a of flange portion 332 of housing 33. The other end face 311b of split core 311 is an end face located on the flange portion 332 side of housing 33, and one end face 311a of split core 311 is an end face located opposite to the flange portion 332 side of housing 33.

[0029] The split core 311 is placed on the flange portion 332 of the housing 33, and then pressed by a pressing plate 34 attached to one end face 311a side and fastened to the housing 33. At this time, a pin 35 is inserted across a pin hole 311f formed in the split core 311, a pin hole 341 formed in the pressing plate 34, and a pin hole 333 formed in the housing 33, so that the position of the split core 311 in the radial direction DR is fixed.

[0030] In addition, the main pole magnet 321 and the spoke magnet 322 (see Figure 4) inserted into the spoke magnet insertion hole 311d (see Figure 4) described later are sandwiched between the flange portion 332 of the housing 33 and the pressure plate 34 to prevent them from falling off the split core 311.

[0031] A rotor core 31 according to one embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a perspective view of the rotor 3 shown in Fig. 2 with the pressing plate 34 removed.

[0032] Rotor core 31 is composed of an assembly of multiple split cores 311. Housing 33 may be referred to as the "rotor housing" to avoid confusion with other housings. Housing 33 is a member that holds multiple split cores 311 together, and can be considered as part of rotor core 31. In other words, rotor core 31 is composed of an assembly of multiple split cores 311 that are divided in the circumferential direction, and non-magnetic rotor housing 33 to which split cores 311 are fastened.

[0033] The rotating electric machine 1 is an embedded magnet type rotating electric machine, and at least one permanent magnet is arranged per pole. For this purpose, at least one magnet insertion hole is provided in the magnetic pole portion 32, and a permanent magnet is inserted into the magnet insertion hole.

[0034] The magnet layout of this embodiment is such that main pole magnets 321 on the d-axis and spoke magnets 322 on the q-axis are alternately arranged in the circumferential direction. Here, the d-axis is an axis that passes through the magnetic pole center of the rotor 3. The q-axis is an axis that passes through the magnetic pole boundary of the rotor 3. When the rotor 3 is skewed, the d-axis and the q-axis are defined in each axial cross section.

[0035] The main pole magnet 321 is magnetized in the radial direction, with the principal surface facing the radial direction of the rotating electric machine 1. The spoke magnets 322 are magnetized in the circumferential direction, with the principal surface facing the circumferential direction of the rotating electric machine 1. In other words, the rotor 3 of this embodiment has a magnet layout of a so-called Halbach array that combines the main pole magnet 321 magnetized in the radial direction and the spoke magnets 322 magnetized in the circumferential direction.

[0036] The magnet insertion holes 311c, 311d into which the main pole magnet 321 and the spoke magnets 322 are inserted will be described with reference to Fig. 5. Fig. 5 is a plan view showing a state in which a plurality of split cores 311 are arranged in the circumferential direction Dθ.

[0037] The rotor core 31 is formed with magnet insertion holes, which are holes for inserting the main pole magnet 321 and the spoke magnets 322. The layout of the magnet insertion holes in this embodiment is such that magnet insertion holes (main pole magnet insertion holes) 311c for inserting the main pole magnet 321 on the d-axis and magnet insertion holes (spoke magnet insertion holes) 311d for inserting the spoke magnets 322 on the q-axis are alternately arranged in the circumferential direction.

[0038] The split core 311 has a d-axis core 311A1 and a back yoke 311A2. The d-axis core 311A1 and the back yoke 311A2 configure a split core main body 311A.

[0039] The d-axis core 311A1 is a part of the rotor core 31, and is a core region located closer to the gap with the stator 2 than the main pole magnet 321. It functions to increase the gap magnetic flux density by collecting the magnetic flux of the main pole magnet 321 and the spoke magnets 322. As a result, the d-axis core 311A1 plays a role in increasing the torque density of the rotating electric machine 1.

[0040] Split core 311 according to one embodiment of the present invention will be described with reference to Fig. 6. Fig. 6 is a perspective view showing split core 311 alone according to one embodiment (first embodiment) of the present invention.

[0041] In this embodiment, a complete main pole magnet insertion hole 311c is formed in one split core 311, and one spoke magnet insertion hole 311d is formed between one split core 311 and the split core 311 adjacent to this split core 311. That is, an incomplete spoke magnet insertion hole 311d is formed in one split core 311. Then, one complete spoke magnet insertion hole 311d is formed by two adjacent split cores 311.

[0042] A main pole magnet 321 (see FIG. 4) and a spoke magnet 322 (see FIG. 4) are inserted into a main pole magnet insertion hole 311c and a spoke magnet insertion hole 311d formed in the split core 311, respectively, to form the magnetic pole portion 32. The main pole magnet insertion hole 311c and the spoke magnet insertion hole 311d are formed so as to penetrate the rotor core 31 (split core 311) in the axial direction DZ.

[0043] The split core 311 of this embodiment has one fastening portion 311e on the inner peripheral side with respect to the main pole magnet insertion hole 321. The fastening portion 311e is formed so as to protrude radially inward from the split core body portion 311A ​​in which the main pole magnet insertion hole 311c and the spoke magnet insertion holes 311d are formed. The fastening portion 311e has an arc-shaped portion on the tip side protruding radially inward. That is, when viewed from the axial direction DZ, the fastening portion 311e is formed so that the end portion on the radially inner side forms an arc shape. Note that the number of fastening portions 311e is not limited to one, and multiple fastening portions 311e may be provided.

[0044] A pin hole 311f is formed in the fastening portion 311e. The pin hole 311f is disposed on the d axis and passes through the split core 311 in the axial direction DZ. The split core 311 is fastened to the housing 33 by a pin 35 inserted into the pin hole 311f.

[0045] In the split core 311, a thin bridge portion 311g is formed in the split core body portion 311A ​​between the main pole magnet insertion hole 311c and the spoke magnet insertion hole 311d. The bridge portion 311g is a narrowed portion of the rotor core 31 disposed between the main pole magnet 321 and the spoke magnets 322. It is desirable to narrow the bridge portion 311g because it becomes a path for leakage magnetic flux that short-circuits the magnetic flux of the main pole magnet 321. On the other hand, since the bridge portion 311g has a thin wall thickness, it is also a portion where large stress occurs due to the load of centrifugal force and electromagnetic force acting on the rotor 3. For this reason, the width of the bridge portion 311g is determined by the balance between magnetic properties such as torque and mechanical strength.

[0046] The split core 311 has split portions 311j between adjacent split cores 311 at a portion of the back yoke 311A2 that constitutes the slots (spoke magnet insertion holes) 311d of the spoke magnets 322. The split core 311 has fastening portions 311e to the housing (rotor housing) 33 between the two split portions 311j provided between the split cores 311 on either side. Each of the two split portions 311j has a protruding portion 311k that protrudes in the circumferential direction. The protruding portions 311k of the two split portions 311j protrude in opposite directions in the circumferential direction. Each has protruding portions 311k that protrude in opposite directions in the circumferential direction.

[0047] That is, each of the two divided portions 311j has a protruding portion 311k that protrudes in the opposite circumferential direction. From another perspective, the divided portion 311j is configured in the protruding portion 311k.

[0048] The split core 311 has a bridge portion 311i protruding in the circumferential direction from the split core body portion 311A ​​on the side of the outer peripheral end face 311h. The outer peripheral end face 311h is an end face facing the gap between the rotor 3 and the stator 2. For this reason, the bridge portion 311i is called the "gap side bridge portion."

[0049] The gap side bridge portion 311i is a narrow portion of the rotor core 31 between the spoke magnet insertion hole 311d and the outer peripheral end surface 311h, and is located near the q-axis. It is desirable to narrow the gap side bridge portion 311i because it becomes a path of leakage magnetic flux that short-circuits the magnetic flux of the permanent magnet. On the other hand, since the gap side bridge portion 311i is a narrow portion, it is also a portion where large stress occurs due to the load of centrifugal force and electromagnetic force acting on the rotor. For this reason, the width of the bridge portion is determined by the balance between magnetic characteristics such as torque and mechanical strength. As long as the gap side bridge portion 311i can hold the spoke magnets 322, a circumferential gap 37 (see FIG. 5) may be provided between the gap side bridge portion 311i of the adjacent split core 311. When the gap 37 is provided, the gap side bridge portion 311i does not become a path of leakage magnetic flux, so it is not necessarily necessary to narrow the width of the gap side bridge portion 311i.

[0050] That is, in the rotor core 31 of this embodiment, the gap side bridge portion 311i constituting the slot (spoke magnet insertion hole) 311d of the spoke magnet 322 is cut so as to be divided in the circumferential direction. By cutting the gap side bridge portion 311i in the circumferential direction, it is possible to reduce leakage magnetic flux of the spoke magnet 322. This makes it possible to increase the main magnetic flux that contributes to torque, thereby enabling the rotary electric machine 1 to have high torque, and therefore high torque density, high output density, and high efficiency. In addition, the cores of each pole can be separated. This makes it possible to improve the material utilization rate when the cores are punched out to manufacture them, and to reduce the loss of materials when manufacturing the rotary electric machine.

[0051] The details of the fastening structure of the split core 311 and its action and effect will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is an enlarged plan view of part VII of the rotor core in Fig. 4. Fig. 8 is an enlarged view of part VIII of the partial cross section of Fig. 7, and is a plan view showing vectors of forces acting on the split core.

[0052] 7, the rotor core 31 is composed of an assembly of multiple split cores 311, and the multiple split cores 311 are fixed to the housing 33 by fastening portions 311e. The multiple split cores 311 have a gap 36 between the protruding portions 311k of two adjacent split cores 311. The presence of the gap 36 makes it possible to reduce leakage magnetic flux from the spoke magnets 322. This makes it possible to increase the main magnetic flux that contributes to torque, thereby enabling the rotating electric machine 1 to have higher torque, and therefore higher torque density, higher power density, and higher efficiency.

[0053] The split portion of two adjacent split cores 311 can be regarded as being composed of split portion (circumferential end surface) 311j of split core 311 and gap 36. In this case, two adjacent split cores 311 have split portions 311j, 36 on the q axis. When split portions 311j, 36 are split on the q axis, protruding portions 311k of each split core 311 can be configured to protrude symmetrically in the circumferential direction. Therefore, the spring force of protruding portion 311k when fixing and supporting split core 311 to rotor housing 33 acts on split core 311 evenly in the circumferential direction. Therefore, in the three-point support of protruding portion 311k and fastening portion 311e, the stress generated in protruding portion 311k is equally divided between two protruding portions 311k, improving the reliability of mechanical strength of protruding portion 311k. This makes it possible to obtain a more robust fixing and supporting structure for split core 311.

[0054] 8, the state of the protrusion 311k before the split core 311 is fastened to the housing 33 is diagrammatically shown by a dotted line 311k'. As shown in FIG. 8, the split core 311 is designed so that the protrusion 311k' and the housing 33 form a negative intersection.

[0055] When split core 311 is fastened to housing 33 by fastening portion 311e, protrusion 311k elastically deforms like a leaf spring, conforms to the shape of housing 33, and continues to contact housing 33. At this time, split core 311 contacts housing 33 at three points: fastening portion 311e and the two protrusions 311k.

[0056] That is, the protruding portion 311k constitutes an elastically deforming portion that is elastically deformed by contacting the rotor housing 33.

[0057] The fastening portion 311e and the two protruding portions 311k each receive forces indicated by arrows in Fig. 8 at three points. That is, the split core 311 is fastened to the housing (rotor housing) 33 such that the fastening portion 311e and the protruding portions 311k receive forces in opposite directions in the radial direction DR. Therefore, the split core 311 is constrained to the housing 33 without any clearance. This suppresses the generation of vibrations and noise in the rotor 3.

[0058] The rotating electric machine 1 of the present embodiment described above has the following features. A rotor 3 having magnets 321, 322 and a rotor core 31 into which the magnets 321, 322 are inserted; A rotating electric machine 1 including a stator 2 facing a rotor 3 with a predetermined gap therebetween, The magnets 321, 322 are composed of a main pole magnet 321 whose magnetization direction faces the radial direction DR of the rotating electric machine 1, and a spoke magnet 322 whose magnetization direction faces the circumferential direction Dθ of the rotating electric machine 1, The rotor core 31 is composed of an assembly of a plurality of split cores 311 divided in the circumferential direction, and a non-magnetic rotor housing 33 to which the split cores 311 are fastened. The split core 311 has a split portion 311j between adjacent split cores 311 at a portion of the back yoke 311A2 that constitutes the slot 311d of the spoke magnet 322, and has a fastening portion 311e to the rotor housing 33 between the two split portions 311j provided between the split cores 311 on both sides. Each of the two divided portions 311j constitutes a protruding portion 311k that protrudes in the opposite direction in the circumferential direction Dθ, The split core 311 is fastened to the rotor housing 33 such that the fastening portion 311e and the protruding portion 311k receive forces in opposite directions in the radial direction DR.

[0059] The rotating electric machine 1 of this embodiment has an inner rotor structure. In this case, a force acting inward (toward the inner periphery) in the radial direction Dθ acts on the fastening portion 311e, and a force acting outward (toward the outer periphery) in the radial direction Dθ acts on the protruding portion 311k. When the rotating electric machine 1 has an outer rotor structure, a force acting outward (toward the outer periphery) in the radial direction Dθ acts on the fastening portion 311e, and a force acting inward (toward the inner periphery) in the radial direction Dθ acts on the protruding portion 311k.

[0060] The main magnetic flux of the split core 311 will be described with reference to Fig. 9. Fig. 9 is a magnetic flux diagram showing a typical main magnetic flux in the split core 311 of Fig. 8.

[0061] The magnet arrangement of the rotor 3 in this embodiment is a Halbach arrangement, and the protrusions 311k are part of the elements that hold the spoke magnets 322, but are not a path of the main magnetic flux that contributes to torque. Therefore, even if the magnetic properties of the protrusions 311k deteriorate due to elastic deformation, deterioration of the magnetic properties in the path of the main magnetic flux can be suppressed.

[0062] A modified example (first modified example) of the split core 311 will be described with reference to Fig. 10. Fig. 10 is a perspective view showing a modified example (first modified example) of the split core 311 of Fig. 6.

[0063] In the split core 311 of this example, a communication groove 311m that communicates the main pole magnet slot 311c and the pin hole 311f is formed in the back yoke 311A2 on the d axis. In other words, the back yoke on the d axis is cut by the communication groove 311m, so that the main pole magnet slot 311c and the pin hole 311f communicate with each other.

[0064] That is, the split core 311 in this example has a pin hole 311f arranged on the d-axis, and is fastened to the rotor housing 33 by a pin 35 inserted into the pin hole 311f, and the back yoke 311A2 on the d-axis is cut, so that the slot 311c of the main pole magnet 321 and the pin hole 311f are in communication with each other.

[0065] When the main pole magnet slot (main pole magnet insertion hole) 311c and the pin hole 311f communicate with each other, the pin hole 311f tends to widen when the pin 35 is driven in. This makes it possible to reduce the clearance at the fastening portion between the split core 311f and the housing 33, and to reduce the residual stress generated in the pin hole 311f. This makes it possible to reduce rattling between the split core 311 and the housing 33, and to improve the ease of assembly of the rotor 3.

[0066] Another modification (second modification) of the split core 311 will be described with reference to Fig. 11. Fig. 11 is a perspective view showing another modification (second modification) of the split core 311 of Fig. 6.

[0067] The split core 311 of this example has a plurality of fastening portions 311e. Providing a plurality of fastening portions 311e on the split core 311 makes it possible to disperse stress that occurs at the fastening portions 311e of the split core 311 when the split core 311 is subjected to centrifugal force, electromagnetic force, or other force due to external vibration, etc. This improves the strength of the rotor core 31 and makes it possible to improve the reliability of the rotating electric machine 1.

[0068] In the above-described rotating electric machine 1, it is preferable to use fractional slots such that the number of slots of the stator 2 is a fraction obtained by dividing the number of phases of the coils 213 by the number of poles of the rotor 3, i.e., the number of slots per pole per phase is a fraction. In this case, the coils 213 inserted into the slots of the stator 2 should be fractional slot concentrated winding in which the coils 213 of the same phase straddle at least two or more consecutive adjacent slots to form a rotating magnetic field.

[0069] In the case of fractional slot concentrated winding, the position (phase) of the stator teeth that a rotor pole faces is different from the position (phase) of the teeth that the adjacent pole faces. That is, for example, the distribution of magnetic flux from a given N pole to an adjacent S pole is different from the distribution of magnetic flux from that S pole to the adjacent N pole. For this reason, if the rotor core 31 is not divided and the back yoke 311A2 of the rotor 3 is continuous, magnetic flux that crosses multiple poles will flow through the back yoke 311A2 due to the asymmetry of the magnetic flux distribution for each pole as described above.

[0070] The magnetic flux flowing through the back yoke 311A2 across the multiple poles is different from the magnetic flux that contributes to torque, and is a magnetic flux that only generates torque pulsation and increases the iron loss of the back yoke 311A2 of the rotor 3.

[0071] In the configuration of this embodiment, the rotor core 31 is configured as a split core 311, so that the split portion 311j can increase the magnetic resistance against the magnetic flux flowing through the back yoke 311A2 across the multiple poles, thereby reducing this magnetic flux.

[0072] As described above, since the split portion 311j of this embodiment is independent of the magnetic path of the main magnetic flux, by applying the split core 311 of this embodiment to fractional slot concentrated winding, it is possible to reduce torque pulsation caused by magnetic flux flowing through the back yoke 311A2 across multiple poles and iron loss generated in the back yoke 311A2 of the rotor 3 without reducing the basic performance of the rotating electric machine 1 such as torque and output. This makes it possible to improve the quietness of the rotating electric machine 1 and the efficiency of the rotating electric machine 1.

[0073] [Example 2] A second embodiment of split core 311 will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a plan view showing a configuration of split core 311 according to an embodiment (second embodiment) of the present invention. Fig. 13 is a perspective view showing a single unit of split core 311 according to an embodiment (second embodiment) of the present invention.

[0074] The split core 311 of this embodiment has a split portion 311j between the adjacent split cores at a portion of the back yoke 311A2 that constitutes the slot 311c of the main pole magnet 321. For this reason, in this embodiment, a complete spoke magnet insertion hole 311d is formed in one split core 311, and one main pole magnet insertion hole 311c is formed between one split core 311 and the split core 311 adjacent to this split core 311. That is, an incomplete main pole magnet insertion hole 311c is formed in one split core 311. And, one complete main pole magnet insertion hole 311c is formed by two adjacent split cores 311.

[0075] Also, the d-axis core 311A1 is divided into two by adjacent split cores 311. Therefore, the d-axis core (core portion on the gap side) 311A1 has a split portion 311n. In this case, the fastening portion 311e provided between the two split portions 311j is provided in the portion of the back yoke 311A2 that constitutes the spoke magnet insertion hole (spoke magnet slot) 311d, which differs from the configuration of the first embodiment.

[0076] The rotating electric machine 1 of this embodiment has the following features. A rotor 3 including magnets 321 and 322 and a rotor core 31 into which the magnets 321 and 322 are inserted; A rotating electric machine 1 including a stator 2 facing a rotor 3 with a predetermined gap therebetween, The magnets 321, 322 are composed of a main pole magnet 321 whose magnetization direction faces the radial direction DR of the rotating electric machine 1, and a spoke magnet 322 whose magnetization direction faces the circumferential direction Dθ of the rotating electric machine 1, The rotor core 31 is composed of an assembly of a plurality of split cores 311 divided in the circumferential direction, and a non-magnetic rotor housing 33 to which the split cores 311 are fastened. The split core 311 has a split portion 311j between adjacent split cores 311 at a portion of the back yoke 311A2 that constitutes the slot 311c of the main pole magnet 321, and has a fastening portion 311e to the rotor housing 33 between the two split portions 311j provided between the split cores 311 on both sides. Each of the two divided portions 311j constitutes a protruding portion 311k that protrudes in the opposite direction in the circumferential direction Dθ, The split core 311 is fastened to the rotor housing 33 such that the fastening portion 311e and the protruding portion 311k receive forces in opposite directions in the radial direction DR.

[0077] In the configuration of this embodiment, the same effects as those of the first embodiment can be obtained.

[0078] In this embodiment, similarly to the first embodiment, the multiple split cores 311 may be configured so that a gap 36 is formed between the protruding portions 311k of two adjacent split cores 311.

[0079] In this embodiment, the split portions of two adjacent split cores 311 can be considered to be composed of the split portions (circumferential end faces) 311j of the split cores 311 and the gaps 36. In this case, the two adjacent split cores 311 have the split portions 311j, 36 on the d axis.

[0080] In this embodiment, as in the first embodiment, it is preferable to use fractional slots in the rotating electric machine 1, where the number of slots in the stator 2 is a fraction obtained by dividing the number of phases of the coils 213 by the number of poles of the rotor 3, that is, the number of slots per pole per phase is a fraction. In this case, it is preferable that the coils 213 inserted into the slots of the stator 2 are fractional slot concentrated windings in which the coils 213 of the same phase straddle at least two or more adjacent slots in succession to form a rotating magnetic field.

[0081] As described above, the split core 311 of this embodiment is cut so that the gap side core portion (d-axis core) 311A1 constituting the slot 311c of the main pole magnet 321 is divided in the circumferential direction. By cutting the gap side core 311A1 in the circumferential direction, the cores of each pole can be separated. This improves the material utilization rate when punching out the core, and reduces the loss of parts when manufacturing the rotating electric machine.

[0082] In this embodiment as well, the protruding portion 311k constitutes an elastically deforming portion that is elastically deformed by contacting the rotor housing 33. This provides the same effects as those of the first embodiment.

[0083] A modification (first modification) of the split core 311 according to the second embodiment will be described with reference to Fig. 14. Fig. 14 is a perspective view showing a modification (first modification) of the split core 311 of Fig. 13 .

[0084] In the split core 311 of this example, a communication groove 311m that communicates between the spoke magnet slot 311d and the pin hole 311f is formed in the back yoke 311A2 on the q axis. In other words, the back yoke 311A2 on the q axis is cut by the communication groove 311m, so that the spoke magnet slot 311d and the pin hole 311f communicate with each other.

[0085] That is, in the rotating electric machine 1 of this embodiment, the split core 311 is configured as follows. The split core 311 has a pin hole 311f arranged on the q axis and is fastened to the rotor housing 33 by a pin 35 (see Figure 12) inserted into the pin hole 311f, and the back yoke 311A2 on the q axis is cut to connect the slot 311d of the spoke magnet 322 to the pin hole 311f.

[0086] The communicating groove 311m of this example differs from the communicating groove 311m of the first embodiment which communicates between the main pole magnet slot 311c and the pin hole 311f in that the communicating groove 311m of this example connects the spoke magnet slot 311d and the pin hole 311f, but it has the same effect as the communicating groove 311m of the first embodiment.

[0087] A modified example (second modified example) of the split core 311 according to the second embodiment will be described with reference to Fig. 15. Fig. 15 is a perspective view showing another modified example (second modified example) of the split core of Fig. 13.

[0088] The split core 311 of this example has a plurality of fastening portions 311e. Providing a plurality of fastening portions 311e on the split core 311 makes it possible to disperse stress that occurs at the fastening portions 311e of the split core 311 when the split core 311 is subjected to centrifugal force, electromagnetic force, or other force due to external vibration, etc. This improves the strength of the rotor core 31 and makes it possible to improve the reliability of the rotating electric machine 1.

[0089] Also, in the rotating electric machine 1 using the split core 311 of this example, similarly to the first embodiment, it is preferable to use fractional slots, where the number of slots in the stator 2 is the number obtained by dividing the number of phases of the coils 213 by the number of poles of the rotor 3, i.e., the number of slots per pole per phase is a fraction. In this case, the coils 213 inserted into the slots of the stator 2 should be fractional slot concentrated winding, in which the coils 213 of the same phase straddle at least two or more adjacent slots in succession to form a rotating magnetic field. This provides the same effects as the first embodiment.

[0090] A modified example (second modified example) of the split core 311 according to the second embodiment will be described with reference to Fig. 16. Fig. 16 is a perspective view showing another modified example (third modified example) of the split core of Fig. 13.

[0091] In this embodiment, the fastening portion 311e of the split core 311 in Fig. 13 is changed from the pinned structure using the pin 35 to a dovetail structure (dovetail groove structure). The other configurations are the same as those in the second embodiment.

[0092] The dovetail structure 311e of this embodiment may be applied to the split core 311 of the first embodiment. Fig. 17 is an enlarged plan view of the rotor core 31 of the first embodiment to which the third modified embodiment is applied. Even if the dovetail structure 311e is used, the split core 311 can be fixed to the rotor core 31 in the same manner as in the first embodiment.

[0093] [Example 3] An embodiment in which a rotating electric machine 1 according to the present invention is mounted on a vehicle (xEV) will be described with reference to Fig. 18. Fig. 18 is a diagram showing the configuration of an xEV 100 that employs a rotating electric machine 1 according to an embodiment of the present invention.

[0094] A rotating electric machine 1 serving as a drive motor is fixedly supported on a bogie 101 by a support member 102. A rotor of the rotating electric machine 1 is coupled to an axle 106, and the rotating electric machine 1 drives wheels 103 via the axle 106. The vehicle 100 includes the rotating electric machine 1, a battery 105, and a power conversion device 107 that converts DC power of the battery 105 into AC power and supplies the AC power to the rotating electric machine 1.

[0095] In the xEV of this embodiment, by including the rotating electric machine 1 of this embodiment, it is possible to improve the space factor of the coil 11 in the slot, reduce losses, and realize a simple coil heat dissipation structure, thereby increasing the power density of the drive motor. This provides an xEV that can obtain high torque and has excellent cost performance.

[0096] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the configurations. In addition, it is possible to add, delete, or replace part of the configuration of the embodiments with other configurations. [Explanation of symbols]

[0097] DESCRIPTION OF THE PREFERRED EMBODIMENTS 1... rotating machine, 2... stator, 3... rotor, 31... rotor core, 33... rotor housing, 35... pin, 36... gap, 37... circumferential gap, 311... split core, 311A1... core portion on the gap side (d-axis core), 311A2... back yoke, 311c... main pole magnet insertion hole (main pole magnet slot), 311d... spoke magnet insertion hole (spoke magnet slot), 311e... fastening portion, 311f... pin hole, 311i... gap side bridge portion, 311j... split portion of split core 311, (311j, 36)... split portion, 311k... protruding portion (elastic deformation portion), 321... magnet (main pole magnet), 322... magnet (spoke magnet).

Claims

1. a rotor having a magnet and a rotor core into which the magnet is inserted; a stator facing the rotor with a predetermined gap therebetween, the magnet is composed of a main pole magnet, the magnetization direction of which faces a radial direction of the rotating electric machine, and a spoke magnet, the magnetization direction of which faces a circumferential direction of the rotating electric machine; the rotor core is composed of an assembly of a plurality of split cores divided in a circumferential direction, and a non-magnetic rotor housing to which the split cores are fastened; the split core has a split portion between adjacent split cores at a portion of a back yoke that defines a slot of the spoke magnet, and has a fastening portion to the rotor housing between two split portions provided between adjacent split cores, Each of the two divided portions constitutes a protruding portion protruding in an opposite direction in the circumferential direction, The split core is fastened to the rotor housing such that the fastening portion and the protruding portion receive forces in opposite radial directions.

2. 2. A rotating electric machine according to claim 1, The plurality of split cores include a gap between the protruding portions of two adjacent split cores.

3. 2. A rotating electric machine according to claim 1, A rotating electric machine in which the two adjacent split cores have split portions on the q axis.

4. 2. A rotating electric machine according to claim 1, Fractional slots, where the number of slots of the stator divided by the number of coil phases and the number of poles of the rotor, i.e., the number of slots per pole per phase, is a fraction; A rotating electric machine in which the coils inserted into the slots of the stator are fractional slot concentrated windings in which coils of the same phase straddle at least two or more adjacent slots in succession to form a rotating magnetic field.

5. 2. A rotating electric machine according to claim 1, A rotating electric machine in which a gap side bridge portion that constitutes a slot of the spoke magnet is cut so as to be divided in the circumferential direction.

6. 2. A rotating electric machine according to claim 1, The split core has a pin hole arranged on a d axis, The split core is fastened to the rotor housing by a pin inserted into the pin hole, The split core has a back yoke on the d-axis cut so that the slots of the main pole magnet communicate with the pin holes.

7. 2. A rotating electric machine according to claim 1, The protrusion constitutes an elastic deformation portion that elastically deforms when in contact with the rotor housing.

8. 2. A rotating electric machine according to claim 1, The split core includes a plurality of fastening portions.

9. a rotor including a magnet and a rotor core into which the magnet is inserted; a stator facing the rotor with a predetermined gap therebetween, the magnet is composed of a main pole magnet, the magnetization direction of which faces a radial direction of the rotating electric machine, and a spoke magnet, the magnetization direction of which faces a circumferential direction of the rotating electric machine; the rotor core is composed of an assembly of a plurality of split cores divided in a circumferential direction, and a non-magnetic rotor housing to which the split cores are fastened; The split core has a split portion between adjacent split cores at a portion of a back yoke that constitutes a slot of the main pole magnet, and has a fastening portion to the rotor housing between two split portions provided between adjacent split cores, Each of the two divided portions constitutes a protruding portion protruding in an opposite direction in the circumferential direction, The split core is fastened to the rotor housing such that the fastening portion and the protruding portion receive forces in opposite radial directions.

10. A rotating electric machine according to claim 9, The plurality of split cores include a gap between the protruding portions of two adjacent split cores.

11. A rotating electric machine according to claim 9, A rotating electric machine in which two adjacent split cores have split portions on a d-axis.

12. A rotating electric machine according to claim 9, Fractional slots, where the number of slots of the stator divided by the number of coil phases and the number of poles of the rotor, i.e., the number of slots per pole per phase, is a fraction; A rotating electric machine in which the coils inserted into the slots of the stator are fractional slot concentrated windings in which coils of the same phase straddle at least two or more adjacent slots in succession to form a rotating magnetic field.

13. A rotating electric machine according to claim 9, The split core is a rotating electric machine in which the core portion on the gap side that defines the slot of the main pole magnet is cut so as to be split in the circumferential direction.

14. A rotating electric machine according to claim 9, The split core has a pin hole arranged on the q axis, The split core is fastened to the rotor housing by a pin inserted into the pin hole, The split core has a back yoke on the q axis cut so that the slots of the spoke magnets communicate with the pin holes.

15. A rotating electric machine according to claim 9, The protrusion constitutes an elastic deformation portion that elastically deforms when in contact with the rotor housing.

16. A rotating electric machine according to claim 9, The split core includes a plurality of fastening portions.

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