JP6013269B2 - Permanent magnet rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine using permanent magnets, and particularly relates to the arrangement of permanent magnets.

  In a rotating electrical machine for industrial use, and further in a rotating electrical machine used for an electric vehicle or a hybrid vehicle, high output is required, and a rotating electrical machine using a permanent magnet can increase the magnetic flux density. A rotary electric machine is used. In order to further improve the output in the permanent magnet type rotating electrical machine, the magnetic flux density on the rotor surface is improved by installing permanent magnets not only near the rotor surface but also on the inner diameter side of the rotor. be able to.

  At this time, if the amount of permanent magnets is increased too much, the rotor core, particularly the inner diameter side of the rotor core, is magnetically saturated, and the magnetic flux density on the rotor surface cannot be improved. In order to increase the amount of permanent magnets, the thickness of the permanent magnets may be changed according to the radial direction. For this purpose, it is conceivable to divide the permanent magnet in the radial direction. Examples of rotating electrical machines using permanent magnets divided in the radial direction include the following.

That is, in some rotors, a pair of permanent magnet pieces having the same shape and the same size are mounted in each magnet insertion hole so as to be opposed to each other in the radial direction. (See Patent Document 1)
Further, there is a permanent magnet divided into two magnets having a thin cross-sectional rectangular shape in the magnet thickness direction, which is the rotor radial direction. (See Patent Document 2)
Furthermore, there existed what comprised the permanent magnet divided | segmented into upper, middle, and lower three in the insertion direction (radial direction of a rotor), and comprised as a divided magnet. (See Patent Document 3)

JP 2007-049805 A JP 2010-141989 JP 2002-218684 A

  In order to further improve the output of the rotating electrical machine, it is possible to improve the magnetic flux density on the rotor surface by providing permanent magnets not only near the rotor surface but also on the inner diameter side of the rotor. However, if the amount of permanent magnets is increased too much, the rotor core, particularly the inner diameter side of the rotor core, is magnetically saturated, and the magnetic flux density on the rotor surface cannot be improved. In Patent Documents 1 to 3, since the circumferential length of the permanent magnet arranged on the outer diameter side and the permanent magnet arranged on the inner diameter side are the same, the amount of the permanent magnets increases too much and the rotor surface There was a problem that it was impossible to improve the magnetic flux density.

  The present invention has been made to solve the above-described problems, and improves the output of the rotating electrical machine by improving the magnetic flux density on the rotor surface in a state where the rotor core is hard to be magnetically saturated. An object of the present invention is to provide a permanent magnet type rotating electrical machine that can perform the above-described operation.

A permanent magnet type rotating electrical machine according to the present invention includes a rotor attached to a rotating shaft, a stator installed on the outer diameter side of the rotor and configured on the same axis as the rotor, and embedded in the rotor. and be one having a permanent magnet radially, permanent magnets, Rutotomoni formed into a rectangular parallelepiped is divided into a plurality of radial direction of the rotating electrical machine, the permanent magnet is divided into a plurality around the rotational axis The permanent magnets are embedded in the rotor so as to be vertically long, and the permanent magnets are arranged so that the same poles oppose each other in the circumferential direction. It is configured to be smaller than the circumferential width of the outer diameter side permanent magnet located on the outer diameter side of the side permanent magnet so that the circumferential width of the inner diameter side permanent magnet is within the circumferential width of the outer diameter side permanent magnet. a permanent magnet on the outer diameter side permanent magnet In which was placed in touch.

  According to the permanent magnet type rotating electric machine configured as described above, the magnetic flux density on the rotor surface can be improved while relaxing the magnetic saturation, and the output of the rotating electric machine can be improved.

FIG. 3 is a cross-sectional view taken along a plane perpendicular to the axial direction of the permanent magnet type rotating electric machine according to the first embodiment. It is the expanded sectional view which expanded and showed a part of rotor. It is the expanded sectional view which expanded and showed a part of rotor. It is the expanded sectional view which expanded and showed a part of rotor. FIG. 5 is an enlarged cross-sectional view showing a part of a rotor of a permanent magnet type rotating electric machine according to a second embodiment. FIG. 5 is an enlarged cross-sectional view showing a part of a rotor of a permanent magnet type rotating electrical machine according to a third embodiment. It is the expanded sectional view which expanded and showed a part of rotor. FIG. 6 is an enlarged cross-sectional view showing an enlarged part of a rotor of a permanent magnet type rotating electric machine according to a fourth embodiment. It is the expanded sectional view which expanded and showed a part of rotor. FIG. 9 is an enlarged cross-sectional view showing a part of a rotor of a permanent magnet type rotating electric machine according to a fifth embodiment. It is the expanded sectional view which expanded and showed a part of rotor.

Embodiment 1 FIG.
1 is a cross-sectional view taken along a plane perpendicular to the axial direction of the permanent magnet type rotating electric machine according to the first embodiment, and FIG. 2 is an enlarged cross-sectional view showing a part of the rotor in FIG. The relationship between the magnetization direction of a permanent magnet and magnetic flux is shown. In the present embodiment, a case where the permanent magnet type rotating electric machine is a synchronous motor will be described. As shown in FIG. 1, in the permanent magnet type rotating electrical machine according to the first embodiment, a rotor 9 is attached to a rotating shaft 10, and a stator 3 is installed on the outer diameter side of the rotor 9. And the stator 3 are configured on the same axis.

  The outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5 are provided radially around the rotation shaft 10 and are embedded in the rotor core 8 so that the same poles oppose each other in the circumferential direction. Further, the outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5 are of a vertically embedded (spoke) type embedded magnet system embedded vertically in the rotor 9.

  In the rotor core 8, a permanent magnet holding material 7 for holding the outer diameter side permanent magnet 4 is provided at a position facing the stator 3 in the radial direction, and the outer diameter side permanent magnet 4 and the inner diameter side are further provided. Spacers 6 are provided between the permanent magnets 5. The rotor core 8 is configured to be laminated in the axial direction by through bolts or caulking. The stator 3 is similarly configured by laminating magnetic members. The circumferential width of the inner diameter side permanent magnet 5 is configured to be smaller than the circumferential width of the outer diameter side permanent magnet 4, and the inner diameter side permanent magnet 5 is disposed within the circumferential width of the outer diameter side permanent magnet 4. ing.

  The magnetization direction 11 of the outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5 is indicated by black arrows in FIG. Further, the magnetic flux 12 produced by the outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5 is distributed as indicated by the outlined thin arrows in FIG. For example, the magnetic flux 12 passes through the rotor core 8 between the adjacent outer diameter side permanent magnets 4 and between the adjacent inner diameter side permanent magnets 5 substantially outward in the radial direction. Further, the magnetic flux passes through the rotor core 8 between the other adjacent outer diameter side permanent magnets 4 and between the other adjacent inner diameter side permanent magnets 5 from the outer diameter side permanent magnet 4 and the outer diameter side permanent magnet 4. It passes toward the inner diameter side permanent magnet 5.

  In FIG. 1, the number of permanent magnets 4 (number of poles) is 10 and the number of slots of stator 3 is 12, and the ratio of the number of poles to the number of slots is 5: 6. Other combinations of the number of poles and the number of slots may be used.

  As shown in FIG. 2, the magnetic flux 12 produced by the outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5 passes through the rotor core 8 in a substantially radial direction. For example, if the outer diameter side permanent magnet 4 having a large width is extended to the inner diameter side, the rotor core portion on the inner diameter side becomes very thin, causing magnetic saturation immediately, and improving the magnetic flux density on the rotor surface. I can't plan. In order to increase the amount of the outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5 without magnetically saturating the rotor core 8, the shape of the permanent magnet is a sector shape having a greater circumferential length toward the outer diameter side, or It is desirable to form a trapezoidal shape. However, fan-shaped or trapezoidal permanent magnets are difficult to make and are not realistic.

  Thus, it is conceivable to combine a substantially rectangular parallelepiped permanent magnet as a practical permanent magnet shape. For example, when the permanent magnet is divided into two in the radial direction, the permanent magnet having a large circumferential length is defined as the outer diameter side permanent magnet 4, and the permanent magnet having a small circumferential length is defined as the inner diameter side permanent magnet 5, the ideal sector shape. Compared with a permanent magnet having a trapezoidal shape, a step is generated in the radial direction of the rotor core 8, so that magnetic saturation is likely to occur, but the inner diameter side permanent magnet 5 having the same circumferential length as the outer diameter side permanent magnet 4 is used. The magnetic saturation is greatly relaxed compared to the case. That is, the magnetic flux density on the rotor surface is improved, and the output density as a rotating electrical machine is also improved. In addition, although the case where it divided into 2 was demonstrated in the above, you may divide | segment into 3 or more divisions.

  When the rotor 9 rotates, centrifugal force is applied to the outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5. Due to the centrifugal force applied to the inner diameter side permanent magnet 5, a force pushed to the outer diameter side is applied to the outer diameter side permanent magnet 4. When the inner diameter side permanent magnet 5 is smaller than the circumferential width of the outer diameter side permanent magnet 4, centrifugal force is applied to the outer diameter side permanent magnet 4 only by the circumferential width of the inner diameter side permanent magnet 5. At that time, the centrifugal force received from the inner diameter side permanent magnet 5 is not uniform in the outer diameter side permanent magnet 4. Therefore, when the spacer 6 is not provided, in the outer diameter side permanent magnet 4, the centrifugal force applied differs depending on the position in the circumferential direction, and a local stress difference occurs. That is, a large difference in force is applied to the position of the outer diameter side permanent magnet 4 corresponding to both ends in the circumferential direction of the inner diameter side permanent magnet 5, and the outer diameter side permanent magnet 4 is likely to be cracked.

  When the spacer 6 is provided, a large stress difference generated at both ends in the circumferential direction of the inner diameter side permanent magnet 5 is applied to the spacer 6, and the stress difference is relaxed in the spacer 6 and transmitted to the outer diameter side permanent magnet 4. Therefore, there is no large stress difference in the outer diameter side permanent magnet 4, and the outer diameter side permanent magnet 4 is less likely to crack. Therefore, by providing the spacer 6, the magnetic flux density on the rotor surface is improved and the output density as a rotating electrical machine is also improved without causing the permanent magnet to break.

  The permanent magnet holding member 7 is provided at the substantially outermost diameter portion of the rotor 9 and held in a wedge shape with respect to the rotor core 8, and the centrifugal force applied to the outer diameter side permanent magnet 4 and the inner diameter side magnet 5. Can be received by the permanent magnet holding member 7. If the spacer 6 is made of a non-magnetic material, the magnetic flux generated from the outer diameter side permanent magnet 4 and the inner diameter side permanent magnet 5 does not pass through the spacer 6, and no extra leakage flux is generated. A decrease in density can be prevented.

  3 and 4 are enlarged sectional views showing a rotor according to another embodiment. In FIG. 3, the circumferential length of the permanent magnet holding member 7 b is configured to be larger than the circumferential length of the outer diameter side permanent magnet 4, and the opening width 8 a of the rotor core 8 is set to the outer diameter side permanent magnet 4. The length in the circumferential direction is approximately the same. In FIG. 4, the circumferential length of the permanent magnet holding member 7 c is substantially the same as the circumferential length of the outer diameter side permanent magnet 4, and the opening width 8 a of the rotor core 8 is set to the outer diameter side permanent. This is smaller than the circumferential length of the magnet 4.

  Even if the permanent magnet holding member is configured in the shape shown in FIGS. 3 and 4, the same effect as that of the permanent magnet holding member 7 in FIG. 1 can be obtained. In addition, when the circumferential position of the inner diameter side permanent magnet 5 is arranged so that the inner diameter side permanent magnet 5 is located at a position that protrudes from the range of the circumferential width of the outer diameter side permanent magnet 4, a spacer is provided in the rotor core 8. A portion where the width of the magnetic flux 12 is narrowed near 6 is formed, and magnetic saturation is likely to occur. It is desirable to arrange so that the circumferential width of the inner diameter side permanent magnet 5 is located at a location that falls within the circumferential width of the outer diameter side permanent magnet 4.

Embodiment 2. FIG.
FIG. 5 is an enlarged cross-sectional view illustrating a part of the rotor of the permanent magnet type rotating electric machine according to the second embodiment. In the first embodiment, the circumferential width of the spacer 6 is substantially equal to the circumferential width of the outer diameter side permanent magnet 4, the spacer 6 takes on the centrifugal force of the inner diameter side permanent magnet 5, and the received centrifugal force is applied to the outer diameter side permanent magnet. A structure that transmits to the magnet 4 and that does not have a locking portion that handles the centrifugal force of the spacer 6 on the rotor core 8 has been described.

  In the present embodiment, the circumferential width of the spacer 6b is configured to be larger than the circumferential width of the outer diameter side permanent magnet 4, and the circumferential width of the outer diameter side permanent magnet 4 is within the circumferential width of the spacer 6b. Configured to fit. The spacer 6 b is configured such that at least the width on the outer diameter side is larger than the circumferential width of the magnet arrangement space provided in the rotor core 8. The rotor core 8 is provided with a spacer locking portion 20 having a circumferential width larger than the circumferential width of the magnet arrangement space so that the spacer 6b larger than the circumferential width of the magnet arrangement space is accommodated. A part of both ends is accommodated in the spacer locking part 20, and it arrange | positions so that the force of the spacer 6b generated by centrifugal force may be locked.

  The centrifugal force acting on the inner diameter side permanent magnet 5 is first transmitted to the spacer 6b. The force transmitted to the spacer 6b is transmitted to the spacer locking portion 20 of the rotor core 8 where both ends of the spacer 6b are locked, and the spacer 6b is supported by the rotor core 8. The spacer 6 b is deformed by the centrifugal force applied to the inner diameter side permanent magnet 5. The deformation of the spacer 6b causes a force to push the outer diameter side permanent magnet 4 radially outward. A part of the centrifugal force acting on the inner diameter side permanent magnet 5 is caused by the spacer locking portion 20 of the rotor core 8. Since it is held, the force acting on the outer diameter side permanent magnet 4 is reduced accordingly. Therefore, as compared with the first embodiment, the outer diameter side permanent magnet 4 is less likely to crack.

Embodiment 3 FIG.
FIG. 6 is an enlarged cross-sectional view showing a part of the rotor of the permanent magnet type rotating electric machine according to the third embodiment. In the first and second embodiments, the case where the shape of the spacer is not particularly defined has been described. In this embodiment, the shape of the spacer is defined. In FIG. 6, the spacer 6 c is configured such that the circumferential length on the outer diameter side is substantially equal to the width of the outer permanent magnet 4, and the circumferential length on the inner diameter side is shorter than the circumferential length on the outer diameter side. ing. The space provided in the rotor core 8 that houses the spacer 6c is also shaped to match the spacer 6c.

  The circumferential length on the outer diameter side of the spacer 6c is substantially equal to the width of the outer diameter side permanent magnet 4, and the circumferential length on the inner diameter side is made shorter than the circumferential length on the outer diameter side. Compared with the case of 1, the circumferential length of the rotor core 8 between the spacers 6c adjacent in the circumferential direction becomes longer as it becomes the inner diameter side. Therefore, as compared with the case of the first embodiment, it is possible to prevent magnetic saturation from being easily generated as the inner diameter is increased.

  FIG. 7 is an enlarged cross-sectional view showing a part of a rotor of a permanent magnet type rotating electrical machine according to another embodiment. In FIG. 7, as in the second embodiment, the outer circumferential side length of the spacer 6d is configured to be larger than the circumferential width of the outer permanent magnet 4, and the spacer 6d has a circumferential diameter on the inner diameter side. The direction length is shorter than the circumferential length on the outer diameter side. The space provided in the rotor core 8 that houses the spacer 6d is also shaped to match the spacer 6d. And it has the spacer latching | locking part 20b along the shape of the spacer 6d.

  Since the circumferential length on the inner diameter side of the spacer 6d is shorter than the circumferential length on the outer diameter side, compared to the case of the second embodiment, the distance between the spacers adjacent in the circumferential direction becomes closer to the inner diameter side. The circumferential length of the rotor core 8 is increased. Therefore, as compared with the case of the second embodiment, it is possible to prevent magnetic saturation from being easily generated as the inner diameter is increased.

Embodiment 4 FIG.
FIG. 8 is an enlarged cross-sectional view showing a part of the rotor of the permanent magnet type rotating electric machine according to the fourth embodiment. In the figure, the spacer 6e is provided with a recess on the surface of the spacer 6e in contact with the inner diameter side permanent magnet 5 so as to surround the inner diameter side permanent magnet 5. A part of the inner diameter side permanent magnet 5 is accommodated in a recess provided in the spacer 6e.

  The spacer 6e and the inner diameter side permanent magnet 5 can be integrated by surrounding the inner diameter side permanent magnet 5 by fitting the spacer 6e and the inner diameter side permanent magnet 5 together or by bonding them. Since the two parts of the spacer 6e and the inner diameter side permanent magnet 5 can be integrated, the number of parts can be reduced by one at the time of assembly, and the assembly performance is improved.

  FIG. 9 is an enlarged sectional view showing a rotor portion according to another embodiment. The spacer 6 f is provided with a convex portion, and the tip end surface of the convex portion is configured to contact the inner diameter side permanent magnet 5. The convex portions provided on the spacer 6f and the circumferential length of the inner diameter side permanent magnet 5 are the same, and are opposed to each other. As an assembling method, first, the inner diameter side permanent magnet 5 is inserted into the rotor core, and then the spacer 6f is inserted. At this time, since the convex portion of the spacer 6f is within the storage space for storing the inner diameter side permanent magnet 5, the spacer 6f can be positioned. For example, even when the circumferential length of the spacer 6f is slightly smaller than the circumferential length of the outer-diameter-side permanent magnet 4, the spacer 6f can be easily arranged at the center portion, so that the assembling performance is improved.

  In this embodiment mode, the case where the spacer shape is deformed and the concave portion and the convex portion are provided in the structure of the first embodiment mode is described. However, the spacer shown in Embodiment Modes 2 and 3 is shown in the present embodiment mode. You may provide a recessed part and a convex part. In particular, in the spacer 6b described in the second embodiment, the circumferential length of the spacer 6b is larger than the circumferential width of the outer diameter side permanent magnet 4, and a part of the spacer 6b is accommodated in the spacer locking portion 20. Since the circumferential width of the spacer 6b is larger than the width of the outer permanent magnet, it is difficult to insert the spacer 6b in the spacer locking portion 20 with almost no gap. If the shapes such as the spacers 6e and 6f according to the present embodiment are adopted, the center positioning of the spacer 6b can be easily and accurately performed, so that a space can be easily generated in the circumferential direction of the spacer locking portion 20. The spacer 6b can be easily inserted in the axial direction. That is, since the spacer 6b can be inserted in a state where the space between the storage space for the outer diameter side permanent magnet 4 and the spacer 6b is increased, the spacer 6b can be easily inserted.

Embodiment 5 FIG.
FIG. 10 is an enlarged sectional view showing a rotor portion of the permanent magnet type rotating electric machine according to the fifth embodiment. In the drawing, two outer diameter side permanent magnets 4b are combined to constitute the entire outer diameter side permanent magnet. The inner diameter side permanent magnet is not divided in FIG. 10, but may be divided. Further, although the outer diameter side permanent magnet 4b is divided into two in FIG. 10, it may be divided into three or more.

  In general, when the thickness (circumferential length) of a permanent magnet is increased, cracks occur during sintering, resulting in a decrease in manufacturability. Therefore, when the circumferential length of the outer diameter side permanent magnet 4 is increased, it is preferable to divide the outer diameter side permanent magnet 4 into a plurality of pieces in the circumferential direction in order to prevent a decrease in manufacturability. Since the spacer 6 exists between the outer diameter side permanent magnet 4b and the inner diameter side permanent magnet 5, even if the outer diameter side permanent magnet is divided into a plurality of parts, the presence of the spacer 6 causes the outer diameter side permanent magnet 4b to The centrifugal force from the inner diameter side permanent magnet 5 can be received over the entire length in the circumferential direction.

  Since there is a permanent magnet holding material 7 at the outer diameter portion of the outer diameter side permanent magnet 4b, the permanent magnet holding material 7 takes charge of the centrifugal force from the outer diameter side permanent magnet 4b. Therefore, even if the outer diameter side permanent magnet 4b is divided into a plurality of parts, the centrifugal force can be maintained substantially evenly. FIG. 11 is an enlarged cross-sectional view showing a rotor portion according to another embodiment. The outer diameter side permanent magnet 4c and the inner diameter side permanent magnet 5b are configured to have the same dimensions (the same circumferential width). The entire outer diameter side permanent magnet is configured using three outer diameter side permanent magnets 4c, and the entire inner diameter side permanent magnet is configured using two inner diameter side permanent magnets 5b. Thus, since the outer diameter side permanent magnet 4c and the inner diameter side permanent magnet 5b are configured by dividing the outer diameter side permanent magnet 5b with the same size permanent magnet in the circumferential direction, the number of parts can be reduced, and the production cost can be reduced. 10 and 11 show the case where the permanent magnet is divided in the circumferential direction with respect to the configuration shown in the first embodiment, the permanent magnet shown in the second, third, and fourth embodiments. You may make it divide | segment into the circumferential direction.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  3 Stator, 4 Outer diameter side permanent magnet, 5 Inner diameter side permanent magnet, 6, 6b, 6c Spacer, 6e Concavity, 6f Convex, 7 Permanent magnet holder, 9 Rotor, 10 Rotating shaft.

Claims (9)

A rotor attached to the rotating shaft;
A stator installed on the outer diameter side of the rotor and configured on the same axis as the rotor;
A permanent magnet type rotating electrical machine having a permanent magnet embedded in the rotor,
The permanent magnet is formed into a rectangular parallelepiped Rutotomoni is divided into a plurality of radial direction of the upper Symbol rotary electric machine,
The permanent magnets divided into a plurality are embedded in the rotor so as to be radially and vertically long around the rotation axis, and the permanent magnets are arranged so that the same poles oppose each other in the circumferential direction,
The circumferential width of the inner diameter side permanent magnet among the plurality of divided permanent magnets is configured to be smaller than the circumferential width of the outer diameter side permanent magnet located on the outer diameter side of the inner diameter side permanent magnet,
The permanent magnet, wherein the inner diameter side permanent magnet is disposed in contact with the outer diameter side permanent magnet so that the circumferential width of the inner diameter side permanent magnet is within the circumferential width of the outer diameter side permanent magnet. Rotary electric machine. The permanent magnet type rotating electric machine according to claim 1, wherein a spacer is provided between the inner diameter side permanent magnet and the outer diameter side permanent magnet. The permanent magnet type rotating electric machine according to claim 2, wherein the spacer is made of a nonmagnetic material. The circumferential width of the spacer is configured to be larger than the circumferential width of the outer diameter side permanent magnet, and the circumferential width of the outer diameter side permanent magnet is set within the circumferential width of the spacer. The permanent magnet type rotating electric machine according to claim 2 or claim 3, wherein 5. The permanent magnet type rotation according to claim 2, wherein a circumferential length on the inner diameter side of the spacer is shorter than a circumferential length on the outer diameter side. Electric. The permanent magnet type rotating electric machine according to any one of claims 2 to 5, wherein a concave portion is provided on a surface of the spacer, and a part of the inner diameter side permanent magnet is accommodated in the concave portion. The permanent structure according to any one of claims 2 to 5, wherein the spacer is provided with a convex portion and a tip end surface of the convex portion is in contact with the inner diameter side permanent magnet. Magnet rotating electric machine. At least one of the inner diameter side permanent magnet and the outer diameter side permanent magnet is divided into a plurality in the circumferential direction, and a permanent magnet holding material is provided on the outer diameter portion of the outer diameter side permanent magnet. The permanent magnet type rotating electrical machine according to any one of claims 1 to 7, wherein the permanent magnet type rotating electrical machine is provided. 9. The permanent magnet type rotating electrical machine according to claim 8, wherein each of the permanent magnets divided into a plurality of parts has the same circumferential width.

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