JP2021112075A - Rotor and rotary electric machine - Google Patents

Abstract

To provide a rotor and a rotary electric machine capable of suppressing eddy current loss of a permanent magnet, suppressing temperature rise of the permanent magnet, and further reducing cost.SOLUTION: A rotor 4 of the rotary electric machine includes a first magnet insertion hole 27 and second magnet insertion holes 41,42, a first magnet 23, a second magnet 24, and an end face plate. The first magnet insertion hole 27 and the second magnet insertion holes 41,42 are formed at predetermined intervals in a circumferential direction of a rotor core 21. The first magnet 23 and the second magnet 24 are embedded in the respective magnet insertion holes 27,41,42. A metal member 51 is inserted into flux barriers 37, 45, 48 of each magnet insertion hole 27, 41, 42. The metal member 51 is in contact with a pair of end plates.SELECTED DRAWING: Figure 5

Description

The present invention relates to a rotor and a rotary electric machine.

As a rotary electric machine, for example, a rotor is arranged in a stator, a plurality of magnet insertion holes are formed at predetermined intervals in the circumferential direction of the rotor, permanent magnets are embedded in the plurality of magnet insertion holes, and a plurality of permanent magnets are embedded in the rotor. It is known that a non-magnetic conductor is arranged in a closed circuit. The non-magnetic conductor is arranged in the rotor so that the magnetic flux from the stator interlinks the inside of the closed circuit.
That is, in the non-magnetic conductor, an induced current is generated when the magnetic flux from the stator to the rotor changes. Therefore, it is possible to suppress a change in the magnetic flux passing through the rotor due to the magnetic flux due to the induced current flowing through the non-magnetic conductor. Thereby, the change of the magnetic flux passing through the rotor can be suppressed and the loss can be reduced (see, for example, Patent Document 1).

Further, among the rotary electric machines, those equipped with a split type permanent magnet are known. In the split type permanent magnet, for example, a normal permanent magnet is divided into a plurality of split magnets, and the plurality of split magnets are integrally bonded. By equipping the rotating electric machine with a split type permanent magnet, it is possible to reduce the apparent electrical conductivity and suppress the fluctuation of the magnetic flux flowing into the permanent magnet. Therefore, the eddy current can be suppressed and the eddy current loss of the permanent magnet can be suppressed. Further, by suppressing the eddy current loss of the permanent magnet, it is possible to suppress the temperature rise of the permanent magnet.

Japanese Unexamined Patent Publication No. 2019-126143

However, in the split type permanent magnet, for example, it is necessary to divide the permanent magnet into a plurality of split magnets and bond the split plurality of split magnets integrally, which hinders cost reduction.

An object of the present invention is to provide a rotor and a rotary electric machine capable of suppressing the eddy current loss of a permanent magnet, suppressing the temperature rise of the permanent magnet, and further suppressing the cost.

In order to solve the above problems, the rotor and the rotary electric machine of the present invention have adopted the following configurations.
(1) According to the rotor of the present invention (for example, rotors 4, 100 in the embodiment), the rotor core (for example, the rotor core 21 in the embodiment) and a plurality of magnets formed at predetermined intervals in the circumferential direction of the rotor core. An insertion hole (for example, a first magnet insertion hole 27 in the embodiment, a pair of second magnet insertion holes 41, 42) and a permanent magnet embedded in the plurality of magnet insertion holes (for example, the first magnet 23 in the embodiment). , The second magnet 24) and a pair of end face plates (for example, the end face plate 26 in the embodiment) provided on the axial end surface (for example, the outer end surface 21a in the embodiment) of the rotor core, and the magnet insertion hole. A metal member (for example, the metal members 51 and 101 in the embodiment) is inserted into the metal member, and the metal member is in contact with the end face plate.

According to this configuration, the metal member can be arranged along the axial direction of the rotor by inserting the metal member into the magnet insertion hole of the rotor core. Further, by bringing the metal member inserted through the magnet insertion hole into contact with the end face plate, a current path (closed circuit) can be formed by the metal member and the end face plate.
By the way, for example, in a rotary electric machine, a rotor is rotated by supplying an alternating current to each coil from an inverter (not shown) controlled by PWM (Pulse Width Modulation). In this rotary electric machine, harmonic components corresponding to the switching frequency and the like are superimposed on the current applied to each coil from the inverter. Therefore, the magnetic flux (magnetic flux density) from the stator to the rotor changes.

An induced current is generated in the metal member by changing the magnetic flux from the stator to the rotor. Therefore, it is possible to suppress fluctuations in the magnetic flux passing through the rotor due to the magnetic flux caused by the induced current flowing through the metal member. Here, the magnetic flux due to the induced current flowing through the metal member cancels only the fluctuating magnetic flux among the magnetic fluxes flowing through the permanent magnet, and does not affect the magnetic flux that does not fluctuate. Therefore, the fluctuation of the magnetic flux flowing through the permanent magnet can be suppressed. As a result, the eddy current can be suppressed and the eddy current loss of the permanent magnet can be suppressed. Further, by suppressing the eddy current loss of the permanent magnet, it is possible to suppress the temperature rise of the permanent magnet.

In addition, a current path (closed circuit) is formed between the metal member and the end face plate so that the fluctuation of the magnetic flux passing through the permanent magnet is suppressed by the magnetic flux due to the induced current flowing through the metal member. Therefore, it is possible to suppress the eddy current, suppress the eddy current loss of the permanent magnet, and suppress the temperature rise of the permanent magnet without dividing the permanent magnet. As a result, the cost of the permanent magnet (that is, the rotor) can be suppressed.
Further, the metal member can be arranged (positioned) along the axis by sandwiching the metal member between the end face plates using the end face plate. As a result, the current path (closed circuit) can be formed with a simple configuration, and the cost of the rotary electric machine can be further suppressed.
In addition, by suppressing the eddy current loss of the permanent magnet and suppressing the temperature rise of the permanent magnet, a permanent magnet having a low coercive force can be used.

(2) The metal member has a tubular shape and may be connected to a cooling medium passage (for example, a second cooling medium passage 58 in the embodiment) provided on the end face plate.

According to this configuration, the metal member has a tubular shape and is connected to a cooling medium passage provided on the end face plate. That is, the hollow portion of the metal member can communicate with the cooling medium passage. Therefore, the refrigerant flowing through the cooling medium passage can be guided to the hollow portion of the metal member. As a result, the temperature rise of the metal member can be suppressed by the refrigerant, and the permanent magnet can be further cooled.

(3) The magnet insertion holes include a magnet insertion portion (for example, the first magnet insertion portion 36 and the second magnet insertion portion 43 and 46 in the embodiment) and a flux barrier (for example, the first flux barrier 37 and the first flux barrier 37 in the embodiment). 2 Outer flux barriers 45,48)
The metal member may be inserted through the flux barrier.

According to this configuration, the magnet insertion hole is formed by the magnet insertion portion and the flux barrier. A metal member was inserted through the flux barrier. Therefore, it is not necessary to form a dedicated insertion hole in order to insert the metal member into the rotor core. As a result, it is possible to suppress the fluctuation of the magnetic flux passing through the permanent magnet with a simple configuration of adding a metal member.

(4) The metal member may be provided on the outer circumference (for example, the outer circumference 21b in the embodiment) side of the rotor with respect to the permanent magnet.

According to this configuration, the metal member is provided on the outer peripheral side of the rotor with respect to the permanent magnet. Therefore, a large distance (pitch) in the circumferential direction of the metal member can be secured.
Here, for example, the circumferential distance of the metal member is proportional to the amount of interlinkage magnetic flux interlinking with the metal member. Further, when the amount of interlinkage magnetic flux increases, the induced current flowing through the metal member can be increased. The induced current suppresses the fluctuation of the magnetic flux of the permanent magnet.
As a result, by securing a large distance in the circumferential direction of the metal member, the induced current flowing through the metal member can be increased, and the fluctuation of the magnetic flux of the permanent magnet can be suitably suppressed.

Further, by providing the metal member on the outer peripheral side of the rotor with respect to the permanent magnet, only the fluctuating magnetic flux flowing through the outer peripheral end of the rotor (that is, both ends of the permanent magnet) of the permanent magnet is induced to flow through the metal member. It can be suppressed by the magnetic flux generated by the current. As a result, it is possible to prevent the magnetic flux that does not fluctuate due to the magnetic flux due to the induced current from being affected, and it is possible to efficiently suppress the fluctuation of the magnetic flux flowing through the permanent magnet.

(5) The metal member may be provided so as to be symmetrical about the d-axis (for example, the d-axis Vd in the embodiment).

According to this configuration, the metal members are provided so as to be symmetrical about the d-axis. The d-axis corresponds to, for example, a virtual straight line that passes through the axis of the rotor and passes through the center of the magnetic pole when viewed from the axial direction of the rotor. As a result, the amount of interlinkage magnetic flux can be made uniform for each magnetic pole, and the degree of cooling can be made uniform (same) for each magnetic pole.

(6) According to the rotary electric machine of the present invention (for example, the rotary electric machine 1 in the embodiment), the rotor and a stator arranged on the outside of the rotor at intervals are provided.

According to this configuration, it is possible to provide a rotary electric machine capable of suppressing the eddy current loss of the permanent magnet, suppressing the temperature rise of the permanent magnet, and further suppressing the cost.

According to the present invention, the eddy current loss of the permanent magnet can be suppressed, the temperature rise of the permanent magnet can be suppressed, and the cost can be suppressed.

It is a schematic block diagram which shows the rotary electric machine of 1st Embodiment which concerns on this invention. It is sectional drawing along the line II-II of FIG. It is a perspective view which shows the rotor of 1st Embodiment. It is an exploded perspective view which shows the rotor of 1st Embodiment. FIG. 5 is an enlarged cross-sectional view of the V portion of FIG. It is sectional drawing which shows the rotor of 1st Embodiment. FIG. 6 is a cross-sectional view taken along the line VII-VII of FIG. FIG. 3 is an enlarged cross-sectional view of the IIX portion of FIG. It is a perspective view which shows the state which one end part of a plurality of metal members is connected to the end face plate of 1st Embodiment. It is a graph which shows the magnetic flux fluctuation in the state of the rotation speed of 8000 rpm, the torque of 100 Nm, and the output of 84 kW of the rotary electric machine of the first embodiment. It is a graph which shows the magnetic flux fluctuation in the state of the rotation speed 15000 rpm, the torque 76 Nm, and the output 120 kW of the rotary electric machine 1 of 1st Embodiment. It is sectional drawing which shows the rotor of the 2nd Embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, a rotary electric machine (that is, a traveling motor) mounted on a vehicle such as a hybrid vehicle or an electric vehicle will be described.

[First Embodiment]
<Rotating machine>
FIG. 1 is a schematic configuration diagram showing a rotary electric machine 1 of the first embodiment. FIG. 1 is a diagram including a cross section cut by a virtual plane including the axis C.
As shown in FIG. 1, the rotary electric machine 1 includes a case 2, a stator 3, a rotor 4, and a shaft 5.

The case 2 has a tubular box shape for accommodating the stator 3 and the rotor 4. A refrigerant (not shown) is housed in the case 2. A part of the stator 3 is immersed in the refrigerant in the case 2. For example, as the refrigerant, ATF (Automatic Transmission Fluid) or the like, which is a hydraulic oil used for lubrication of a transmission, power transmission, or the like, is used.
The shaft 5 is rotatably supported by the case 2. In FIG. 1, reference numeral 6 indicates a bearing that rotatably supports the shaft 5. Hereinafter, the direction along the axis C of the shaft 5 is referred to as the “axial direction”, the direction orthogonal to the axis C is referred to as the “diameter direction”, and the direction around the axis C is referred to as the “circumferential direction”.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.
As shown in FIGS. 1 and 2, the stator 3 includes a stator core 11 and a plurality of layers (for example, U phase, V phase, W phase) coils 12 mounted on the stator core 11.
The stator core 11 has an annular shape arranged coaxially with the axis C. The stator core 11 is fixed to the inner peripheral surface of the case 2. For example, the stator core 11 is formed by laminating a plurality of electromagnetic steel sheets (silicon steel sheets) in the axial direction. The stator core 11 may be a so-called compaction core obtained by compression molding a metal magnetic powder (soft magnetic powder).

The stator core 11 has a slot 13 into which the coil 12 is inserted. A plurality of slots 13 are arranged at intervals in the circumferential direction. The coil 12 includes an insertion portion 12a inserted into the slot 13 of the stator core 11 and a coil end portion 12b protruding axially from the stator core 11. The stator core 11 generates a magnetic field when a current flows through the coil 12.

<Rotor>
FIG. 3 is a perspective view showing the rotor 4 of the first embodiment.
As shown in FIGS. 1 and 3, the rotors 4 are arranged at intervals inside the stator 3 in the radial direction. The rotor 4 is fixed to the shaft 5. The rotor 4 is configured to be rotatable around the axis C integrally with the shaft 5. The rotor 4 includes a rotor core 21, a first magnet 23 and a second magnet 24 (see FIG. 2), and an end face plate 26. The first magnet 23 and the second magnet 24 are, for example, permanent magnets.

The rotor core 21 has an annular shape arranged coaxially with the axis C. The rotor core 21 has a shaft fixing hole 8 in which the shaft 5 is press-fitted and fixed inside in the radial direction. The rotor core 21 is formed by laminating a plurality of electromagnetic steel sheets (silicon steel sheets) in the axial direction. The rotor core 21 may be a so-called compaction core obtained by compression molding a metal magnetic powder (soft magnetic powder).

FIG. 4 is an exploded perspective view showing the rotor 4 of the first embodiment.
As shown in FIGS. 1 and 4, the pair of end face plates 26 are provided in a state of being in contact with both outer end faces (axial end faces) 21a in the axial direction with respect to the rotor core 21. The end face plate 26 covers a plurality of first magnet insertion holes 27 and a plurality of second magnet insertion hole groups 28 in the rotor core 21 from both ends in the axial direction.

The rotor core 21 has a plurality of first magnet insertion holes (magnet insertion holes) 27 and a plurality of second magnet insertion holes 28 that penetrate the rotor core 21 in the axial direction. The first magnet insertion hole 27 and the second magnet insertion hole group 28 are arranged side by side in the radial direction in the rotor core 21, and a plurality of the first magnet insertion holes 27 and the second magnet insertion hole group 28 are formed at predetermined intervals in the circumferential direction.
In the rotor 4, the electromagnetic steel plate of the rotor core 21 is formed of a magnetic material, and the first magnet 23 and the second magnet are inserted into the two first magnet insertion holes 27 and the second magnet insertion holes 28 arranged in the radial direction. A set of magnets 24 constitutes one magnetic pole portion (magnetic pole) 31. That is, the rotary electric machine 1 is a permanent magnet embedded rotary electric machine (IPM (Interior Permanent Magnet) motor) in which the first magnet 23 and the second magnet 24 are embedded in the first magnet insertion hole 27 and the second magnet insertion hole group 28. It is a rotor of.

FIG. 5 is an enlarged cross-sectional view of the V portion of FIG.
As shown in FIGS. 4 and 5, the plurality of first magnet insertion holes 27 are arranged at intervals in the circumferential direction on the outer peripheral portion of the rotor core 21. However, in FIGS. 4 and 5, only one first magnet insertion hole 27 is shown. The first magnet insertion hole 27 is formed symmetrically in the circumferential direction with the d-axis Vd, which will be described later, as the center when viewed from the axial direction. Specifically, the first magnet insertion hole 27 is formed to be convexly curved toward the shaft 5 (see FIG. 1), and both ends of the curved longitudinal direction extend to the vicinity of the outer circumference 21b of the rotor core 21.

The first magnet insertion hole 27 has a first magnet insertion portion (magnet insertion portion) 36 and a pair of first flux barriers (flux barriers) 37. The first magnet insertion portion 36 is located at the center of the first magnet insertion hole 27 in the longitudinal direction. The first flux barrier 37 extends from both ends of the first magnet insertion portion 36 to the vicinity of the outer circumference 21b of the rotor core 21. The outer end 37a of the first flux barrier 37 extends to the vicinity of the outer circumference 21b of the rotor core 21.

The first magnet 23 is inserted into the first magnet insertion portion 36. The first magnet 23 is inserted so that the magnetic poles are alternately inverted in the circumferential direction. For example, assuming that the outer peripheral side of the magnetic pole portion 31 is N pole, the first magnet 23 is inserted into the first magnet insertion hole 27 (first magnet insertion portion 36) so that the outer peripheral side of the adjacent magnetic pole portion is S pole. Has been done.

The plurality of second magnet insertion holes 28 are formed at positions corresponding to the plurality of first magnet insertion holes 27 in the radial direction. The second magnet insertion hole group 28 has a pair of second magnet insertion holes (magnet insertion holes) 41 and 42. The pair of second magnet insertion holes 41, 42 are formed symmetrically in the circumferential direction with the d-axis Vd, which will be described later, as the center when viewed from the axial direction. Specifically, the pair of second magnet insertion holes 41 and 42 are arranged so as to form a convex V-shape toward the shaft 5 (see FIG. 1). The pair of second magnet insertion holes 41, 42 are formed in a curved shape at positions adjacent to each other in the circumferential direction, and the outer end portion extends to the vicinity of the outer circumference 21b of the rotor core 21.

One of the second magnet insertion holes 41 has a second magnet insertion portion (magnet insertion portion) 43, a second inner flux barrier 44, and a second outer flux barrier (flux barrier) 45. The second magnet insertion portion 43 is located at the center of one of the second magnet insertion holes 41 in the longitudinal direction. The second inner flux barrier 44 extends from the radial inner end of the second magnet insertion portion 43 toward the shaft 5 (see FIG. 1). Further, the second outer flux barrier 45 extends from the radial outer end of the second magnet insertion portion 43 to the vicinity of the outer circumference 21b of the rotor core 21.

The other second magnet insertion hole 42 has a second magnet insertion portion (magnet insertion portion) 46, a second inner flux barrier 47, and a second outer flux barrier (flux barrier) 48. The second magnet insertion portion 46 is located at the center of the other second magnet insertion hole 42 in the longitudinal direction. The second inner flux barrier 47 extends from the radial inner end of the second magnet insertion portion 46 toward the shaft 5 (see FIG. 1). Further, the second outer flux barrier 48 extends from the radial outer end of the second magnet insertion portion 46 to the vicinity of the outer circumference 21b of the rotor core 21.

The second magnet 24 is inserted into one second magnet insertion portion 43 and the other second magnet insertion portion 46. Similar to the first magnet 23, the pair of second magnets 24 are inserted so that the magnetic poles are alternately inverted in the circumferential direction. For example, assuming that the outer peripheral side of the magnetic pole portion 31 has an N pole, the adjacent magnetic pole portions have a pair of second magnets 24 having one second magnet insertion portion 43 and the other second magnet so that the outer peripheral side thereof has an S pole. It is inserted into the insertion portion 46.

Here, the arrow Vd indicates the d-axis direction of the magnetic pole portion 31 composed of the first magnet 23 and the pair of second magnets 24. The d-axis Vd corresponds to a virtual straight line (that is, a virtual straight line passing through the center of the magnetic pole) that passes through the axis C and bisects between a pair of V-shaped second magnets 24 when viewed from the axial direction. do.

As shown in FIGS. 3 and 5, of the pair of first flux barriers 37, the metal member 51 is inserted in the vicinity of the outer circumference 21b of the rotor core 21. The metal member 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the first magnet 23. The metal member 51 is formed in, for example, a cylindrical cylinder and has a hollow portion 52. The metal member 51 is not limited to a cylinder, and may be a hollow member having another shape such as a rectangle.

Further, in the second outer flux barrier 45, the metal member 51 is inserted in the vicinity of the outer circumference 21b of the rotor core 21. One metal member 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the one second magnet 24. Further, in the other second outer flux barrier 48, the metal member 51 is inserted in the vicinity of the outer circumference 21b of the rotor core 21. The other metal member 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the other second magnet 24.

That is, the metal member 51 is inserted through the pair of first flux barriers 37 and the pair of second outer flux barriers 45 and 48. Further, the metal member 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the first magnet 23. Further, the metal member 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the second magnet 24.
The metal member 51 is formed of a non-magnetic material having conductivity such as copper.

In a state where the metal member 51 is inserted through the pair of first flux barriers 37, the voids of the pair of first flux barriers 37 are filled with the resin 55. Further, in a state where the metal member 51 is inserted through the pair of second outer flux barriers 45 and 48, the voids of the pair of second outer flux barriers 45 and 48 are filled with the resin 55. Further, the voids of the pair of second inner flux barriers 44 are filled with the resin 55.

FIG. 6 is a cross-sectional view showing the rotor 4 of the first embodiment. FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG.
As shown in FIGS. 6 and 7, both ends 51a and 51b of the metal member 51 are in contact with a pair of end face plates 26. The end face plate 26 has a plurality of first cooling medium passages 57 and a second cooling medium passage (cooling medium passage) 58.
The plurality of first cooling medium passages 57 are second cooled from the inner peripheral surface 26b of the end face plate 26 inside the end face plate 26 along a line extending radially from the axis C toward the outer peripheral surface 26a of the end face plate 26. It extends to the medium passage 58. In the first cooling medium passage 57, the inner end portion 57a is opened to the inner peripheral surface 26b of the end face plate 26, and the outer end portion 57b is opened to the second cooling medium passage 58. The inner end portion 57a of the first cooling medium passage 57 communicates with the cooling medium passage (not shown) of the shaft 5.

The second cooling medium passage 58 is formed in an annular shape along the outer peripheral surface 26a in the vicinity of the inside of the outer peripheral surface 26a of the end face plate 26 in the inside of the end face plate 26. The outer end portion 57b of the first cooling medium passage 57 communicates with the second cooling medium passage 58. That is, the second cooling medium passage 58 communicates with the cooling medium passage of the shaft 5 via the first cooling medium passage 57.

FIG. 8 is an enlarged cross-sectional view of the IIX portion of FIG. FIG. 9 is a perspective view showing a state in which one end portions 51a of a plurality of metal members 51 are connected to the end face plate 26.
As shown in FIGS. 8 and 9, one end portion 51a of the plurality of metal members 51 is connected to the back surface 26c of one end face plate 26 in a crimped state, for example. That is, one end portion 51a of the metal member 51 is held in a state of being connected to the back surface 26c of one end face plate 26 and in a state of being connected to one of the second cooling medium passages 58. As a result, in the one end portion 51a of the metal member 51, the hollow portion 52 communicates with one of the second cooling medium passages 58.

As shown in FIG. 6, the other end portion 51b of the metal member 51 is held in a state of being connected to the back surface 26c of the other end face plate 26 and in a state of being connected to the other second cooling medium passage 58. .. As a result, in the other end portion 51b of the metal member 51, the hollow portion 52 communicates with the second cooling medium passage 58 of the other end face plate 26.
That is, the hollow portion 52 of the plurality of metal members 51 communicates with the cooling medium passage of the shaft 5 via the plurality of first cooling medium passages 57 (see also FIG. 7) and the pair of second cooling medium passages 58. ..

Further, one end portion 51a of the metal member 51 is connected to the back surface 26c of one end face plate 26, and the other end portion 51b of the metal member 51 is connected to the back surface 26c of the other end face plate 26, whereby a pair of end face plates. A metal member 51 is sandwiched between a pair of end face plates 26 by using 26.
Further, by connecting one end 51a and the other end 51b of the metal member 51 to the back surface 26c of the pair of end face plates 26, a current path (closed circuit) is formed by the metal member 51 and the pair of end face plates 26. Has been done.
The reason why the current path (closed circuit) is formed by the metal member 51 and the pair of end face plates 26 and the hollow portions 52 of the plurality of metal members 51 are communicated with the cooling medium passage of the shaft 5 will be described in detail later.

Returning to FIG. 5, among the plurality of metal members 51, the pair of metal members 51 inserted through the pair of first flux barriers 37 are provided symmetrically in the circumferential direction with the d-axis Vd as the center when viewed from the axial direction. Has been done. Further, among the plurality of metal members 51, the pair of metal members 51 inserted through the pair of second outer flux barriers 45 and 48 are provided symmetrically in the circumferential direction with the d-axis Vd as the center when viewed from the axial direction. ing.

Next, the inflow magnetic flux analysis result will be described with reference to FIGS. 10 and 11.
FIG. 10 is a graph showing magnetic flux fluctuations in a state where the rotation speed of the rotary electric machine 1 is 8000 rpm, the torque is 100 Nm, and the output is 84 kW. FIG. 11 is a graph showing magnetic flux fluctuations in a state where the rotation speed of the rotary electric machine 1 is 15,000 rpm, the torque is 76 Nm, and the output is 120 kW.
In FIGS. 10 and 11, the vertical axis shows the fluctuation of the magnetic flux flowing into the surfaces of the first magnet 23 and the second magnet 24. The horizontal axis indicates the electric angle. Further, the solid line graphs G1 and G3 show the magnetic flux fluctuation of the rotary electric machine 1 of the first embodiment in which the metal member 51 is inserted through the pair of the first flux barrier 37 and the pair of the second outer flux barriers 45 and 48. .. The broken line graphs G2 and G4 show the magnetic flux fluctuations of the rotating electric machine of the comparative example in which the metal member 51 is not inserted through the pair of the first flux barrier 37 and the pair of the second outer flux barriers 45 and 48.

As shown in graphs G1 and G2 of FIG. 10, the rotary electric machine 1 of the first embodiment has a magnetic flux fluctuation of approximately 1/1 of that of the rotary electric machine of the comparative example in a state of a rotation speed of 8000 rpm, a torque of 100 Nm, and an output of 84 kW. It can be suppressed to 10.
As shown in graphs G3 and G4 of FIG. 11, the rotary electric machine 1 of the first embodiment has a magnetic flux fluctuation of approximately 1/1 of that of the rotary electric machine of the comparative example in a state of a rotation speed of 15,000 rpm, a torque of 76 Nm, and an output of 120 kW. It can be suppressed to 10.

That is, according to the rotary electric machine 1 of the first embodiment, an induced current can be passed through the metal member 51 by forming a current path (closed circuit) by the metal member 51 and the pair of end face plates 26. The magnetic flux due to the induced current flowing through the metal member 51 can cancel only the fluctuating magnetic flux among the magnetic fluxes flowing through the first magnet 23 and the second magnet 24. Therefore, the fluctuation of the magnetic flux flowing through the first magnet 23 and the second magnet 24 can be suppressed. As a result, the eddy current can be suppressed and the eddy current loss of the first magnet 23 and the second magnet 24 can be suppressed.

On the other hand, it is conceivable that the loss of the metal member 51 increases when the metal member 51 is inserted through the pair of the first flux barrier 37 and the pair of the second outer flux barriers 45 and 48.
However, it is possible to secure a large suppression of eddy current loss as compared with the loss of the metal member 51. As a result, as shown in the graph G1 of FIG. 10 and the graph G3 of FIG. 11, fluctuations in the magnetic flux flowing into the surfaces of the first magnet 23 and the second magnet 24 of the rotary electric machine 1 can be satisfactorily suppressed.

As described above, the rotary electric machine 1 of the first embodiment rotates the metal member 51 by inserting the metal member 51 into the pair of the first flux barrier 37 and the pair of the second outer flux barriers 45 and 48. Can be placed along the axial direction of. Further, by connecting the metal member 51 to the pair of end face plates 26, a current path (closed circuit) is formed by the metal member 51 and the pair of end face plates 26.

By the way, for example, in the rotary electric machine 1, the rotor 4 rotates by supplying an alternating current to each coil 12 from an inverter (not shown) which is PWM-controlled (not shown). In the rotary electric machine 1 including the coil 12 distributed and wound around the stator core 11, harmonic components corresponding to the switching frequency and the like are superimposed on the current applied to each coil 12 from the inverter. Therefore, the magnetic flux (magnetic flux density) from the stator 3 to the rotor 4 changes.
An induced current is generated in the metal member 51 by changing the magnetic flux from the stator 3 to the rotor 4. Therefore, the fluctuation of the magnetic flux passing through the rotor 4 can be suppressed by the magnetic flux due to the induced current flowing through the metal member 51.

Here, the magnetic flux due to the induced current flowing through the metal member 51 cancels only the fluctuating magnetic flux among the magnetic fluxes flowing through the first magnet 23 and the second magnet 24, and does not affect the magnetic flux that does not fluctuate. Therefore, the fluctuation of the magnetic flux flowing through the first magnet 23 and the second magnet 24 can be suppressed. As a result, the eddy current can be suppressed and the eddy current loss of the first magnet 23 and the second magnet 24 can be suppressed. Further, by suppressing the eddy current loss of the first magnet 23 and the second magnet 24, it is possible to suppress the temperature rise of the first magnet 23 and the second magnet 24.

Further, a current path (closed circuit) is formed by the metal member 51 and the pair of end face plates 26. Therefore, the fluctuation of the magnetic flux passing through the first magnet 23 and the second magnet 24 is suppressed by the magnetic flux due to the induced current flowing through the metal member 51. Therefore, without dividing the first magnet 23 and the second magnet 24, the eddy current is suppressed to suppress the eddy current loss of the first magnet 23 and the second magnet 24, and the first magnet 23 and the second magnet 24 It is possible to suppress the temperature rise. Thereby, the cost of the first magnet 23 and the second magnet 24 (that is, the rotary electric machine 1) can be suppressed.

Further, the metal member 51 is sandwiched between the pair of end face plates 26 by utilizing the pair of end face plates 26. Therefore, the metal member 51 can be arranged (positioned) along the axis C by the pair of end face plates 26. As a result, the current path (closed circuit) can be formed with a simple configuration, and the cost of the rotary electric machine 1 can be further suppressed.
In addition, by suppressing the eddy current loss of the first magnet 23 and the second magnet 24 and suppressing the temperature rise of the first magnet 23 and the second magnet 24, the first magnet 23 and the second magnet having a low coercive force are suppressed. A magnet 24 can be used.

Further, the hollow portions 52 of the plurality of metal members 51 communicate with the cooling medium passages of the shaft 5 via the plurality of first cooling medium passages 57 and the pair of second cooling medium passages 58. Therefore, the refrigerant (for example, ATF) flowing through the cooling medium passage of the shaft 5 is passed through the plurality of first cooling medium passages 57 and the pair of second cooling medium passages 58 by the centrifugal force of the rotor 4 of the plurality of metal members 51. It can be led to the hollow portion 52. As a result, the temperature rise of the metal member 51 can be suppressed by the refrigerant, and the first magnet 23 and the second magnet 24 can be further cooled.

Further, the metal member 51 is inserted through the pair of first flux barriers 37 and the pair of second outer flux barriers 45 and 48. Therefore, in order to insert the metal member 51 through the rotor core 21, it is not necessary to form a dedicated insertion hole in the rotor core 21. As a result, the fluctuation of the magnetic flux passing through the first magnet 23 and the second magnet 24 can be suppressed by a simple configuration in which the metal member 51 is simply added.

In addition, the metal member 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the first magnet 23. Therefore, the distance (pitch) L1 (see FIG. 5) in the circumferential direction of the pair of metal members 51 provided on the outer peripheral surface 21b side of the rotor core 21 is larger than that of the first magnet 23.
Further, the metal member 51 is provided on the outer peripheral surface 21b side of the rotor core 21 with respect to the second magnet 24. Therefore, the distance (pitch) L2 (see FIG. 5) in the circumferential direction of the pair of metal members 51 provided on the outer peripheral surface 21b side of the rotor core 21 is larger than that of the second magnet 24.

Here, for example, the circumferential distances L1 and L2 of the metal member 51 are proportional to the amount of interlinkage magnetic flux interlinking with the metal member 51. Further, when the amount of interlinkage magnetic flux increases, the induced current flowing through the metal member 51 can be increased. The induced current suppresses the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24. As a result, by securing a large distance L1 and L2 in the circumferential direction of the metal member 51, the induced current flowing through the metal member 51 can be increased, and the fluctuation of the magnetic flux of the first magnet 23 and the second magnet 24 can be suitably suppressed.

Further, the metal member 51 is provided on the outer peripheral surface 21b side of the rotor 4 with respect to the first magnet 23 and the second magnet 24. Therefore, of the first magnet 23 and the second magnet 24, only the fluctuating magnetic flux flowing through the ends of the rotor 4 on the outer peripheral surface 21b side (that is, both ends of the first magnet 23 and the second magnet 24) flows through the metal member 51. It can be suppressed by the magnetic flux due to the induced current. As a result, it is possible to prevent the magnetic flux that does not fluctuate due to the magnetic flux due to the induced current from being affected, and it is possible to efficiently suppress the fluctuation of the magnetic flux flowing through the first magnet 23 and the second magnet 24.

Further, the pair of metal members 51 inserted through the pair of first flux barriers 37 are provided symmetrically in the circumferential direction with the d-axis Vd as the center. Further, the pair of metal members 51 inserted through the pair of second outer flux barriers 45 and 48 are provided symmetrically in the circumferential direction with the d-axis Vd as the center. As a result, the amount of interlinkage magnetic flux can be made uniform for each magnetic pole portion 31, and the degree of cooling can be made uniform (same) for each magnetic pole portion 31.

[Second Embodiment]
Next, the rotor 100 of the second embodiment will be described with reference to FIG. In the second embodiment, the same and similar components as the rotor 4 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
FIG. 12 is a cross-sectional view showing the rotor 100 of the second embodiment.
In the rotor 100, the metal member 51 of the first embodiment is replaced with the metal member 101, and the resin 55 of the first embodiment is removed from the voids of the flux barriers 37, 44, 45, 47, 48, and the like. The configuration of is the same as that of the rotor 4 of the first embodiment. Each of the flux barriers 37, 44, 45, 47, 48 is a pair of first flux barriers 37, a pair of second inner flux barriers 44, 47, and a pair of second outer flux barriers 45, 48.

The metal member 101 is formed, for example, in a solid circular cross section. The metal member 51 is not limited to a circular cross section, and may be a solid member having another shape such as a rectangular cross section. The metal member 101 is formed of a non-magnetic material having conductivity such as copper.
The metal member 101 is inserted through a pair of first flux barriers 37 and a pair of second outer flux barriers 45 and 48, similarly to the rotor 4 of the first embodiment. One end of the metal member 101 is connected to the back surface 26c (see FIG. 6) of one end face plate 26, and the other end of the metal member 101 is connected to the back surface 26c (see FIG. 6) of the other end face plate 26. ..
Therefore, a current path (closed circuit) is formed by the metal member 101 and the pair of end face plates 26. As a result, fluctuations in the magnetic flux passing through the first magnet 23 and the second magnet 24 can be suppressed by the magnetic flux due to the induced current flowing through the metal member 101.

Further, the flux barriers 37, 45, and 48 are communicated with the cooling medium passage of the shaft 5 via the plurality of first cooling medium passages 57 and the pair of second cooling medium passages 58. Therefore, the refrigerant (for example, ATF) flowing through the cooling medium passage of the shaft 5 is passed through the plurality of first cooling medium passages 57 and the pair of second cooling medium passages 58 by the centrifugal force of the rotor 4, and the flux barriers 37 and 45 are respectively. , 48 can be led. As a result, the temperature rise of the metal member 101 can be suppressed by the refrigerant, and the first magnet 23 and the second magnet 24 can be further cooled.
As described above, the rotor 100 of the second embodiment can obtain the same effect as the rotor 4 of the first embodiment.

In the above-described embodiment, the rotary electric machine 1 has been described by giving an example of being applied to a traveling motor mounted on a vehicle such as a hybrid vehicle or an electric vehicle, but the present invention is not limited to this. For example, the rotary electric machine 1 may be a motor for power generation, a motor for other purposes, or a rotary electric machine (including a generator) other than for vehicles.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and configurations can be added, omitted, replaced, and other changes can be made without departing from the spirit of the present invention. Yes, it is also possible to appropriately combine the above-mentioned modification examples.

1 Rotating machine 3 Stator 4,100 Rotor 21 Rotor core 21a Outer end face of rotor core (axial end face)
21b Outer circumference 23 First magnet (permanent magnet)
24 Second magnet (permanent magnet)
26 End face plate 27 First magnet insertion hole (magnet insertion hole)
28 Second magnet insertion hole group 36 First magnet insertion part (magnet insertion part)
37 1st Flux Barrier (Flux Barrier)
41, 42 A pair of second magnet insertion holes (magnet insertion holes)
43,46 2nd magnet insertion part (magnet insertion part)
45,48 2nd outer flux barrier (flux barrier)
51,101 Metal member 55 Resin 57 First cooling medium passage 58 Second cooling medium passage (cooling medium passage)
Vd d axis

Claims (6)

With the rotor core
A plurality of magnet insertion holes formed at predetermined intervals in the circumferential direction of the rotor core, and
Permanent magnets embedded in the plurality of magnet insertion holes and
A pair of end face plates provided on the axial end faces of the rotor core,
With
A rotor characterized in that a metal member is inserted into the magnet insertion hole, and the metal member is in contact with the end face plate. The rotor according to claim 1, wherein the metal member has a tubular shape and is connected to a cooling medium passage provided on the end face plate. The magnet insertion hole includes a magnet insertion portion and a flux barrier.
The rotor according to claim 1 or 2, wherein the metal member is inserted through the flux barrier. The rotor according to any one of claims 1 to 3, wherein the metal member is provided on the outer peripheral side of the rotor with respect to the permanent magnet. The rotor according to any one of claims 1 to 4, wherein the metal member is provided so as to be symmetrical with respect to the d-axis. The rotor according to any one of claims 1 to 5,
A stator arranged on the outside of the rotor at intervals,
A rotary electric machine characterized by being equipped with.

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