JP5542423B2 - Rotating electric machine rotor and rotating electric machine - Google Patents

Description

  The present invention relates to a rotor of a permanent magnet type rotating electrical machine in which a permanent magnet is provided on a rotor core, and the rotating electrical machine.

  2. Description of the Related Art Conventionally, an electric motor as a rotating electric machine has a permanent magnet in which a plurality of phases, for example, U-phase, V-phase, and W-phase coils are wound around a stator core and a permanent magnet as a magnetic pole is provided on the rotor core. A type of electric motor (hereinafter referred to as a permanent magnet electric motor) is known. In such a permanent magnet motor, the current supplied to the coil wound around the stator core and the number of turns of the coil tend to increase in order to reduce the size, increase the torque, and increase the output. In this case, the magnetomotive force generated from the stator side is also increased, and this magnetomotive force acts on the permanent magnet provided on the rotor, so that the permanent magnet may be demagnetized as a demagnetizing field. Therefore, for example, in the rotor of Patent Document 1, a rotor made of a non-magnetic material at a portion where a permanent magnet is easily demagnetized, for example, an end face on which a stepped skew is formed (hereinafter referred to as a skew face). A punching plate is provided to reduce demagnetization of the permanent magnet.

JP 2009-136040 A

  However, in the configuration of Patent Document 1 described above, since there is no permanent magnet in the rotor punched plate portion made of a non-magnetic material, the performance of the rotating electrical machine may be deteriorated. Instead, it may be possible to reduce the demagnetization by forming the permanent magnet with a magnetic material with high coercive force, but the magnetic material with high coercive force is expensive, so the permanent magnet is formed with a magnetic material with high coercive force. Then, there exists a problem that material cost increases significantly. On the other hand, if a permanent magnet is formed of a magnetic material having a low coercive force and the thickness thereof is increased to increase the resistance to demagnetization, the structure costs increase as the weight and dimensions of the permanent magnet increase in addition to the increase in material cost. There is also a problem that it leads to an increase in size and, consequently, an increase in the size of the permanent magnet motor.

  The present invention has been made in view of the above circumstances, and its object is to increase the demagnetization resistance of a permanent magnet without causing a significant increase in material cost and without increasing the size of the structure. An object of the present invention is to provide a rotor for a rotating electrical machine and a rotating electrical machine.

The rotor of the rotating electrical machine according to the present invention includes a rotor core and a pair of magnetic body inserts that are provided in plural with a constant interval in the circumferential direction of the rotor core, and whose opposing distances gradually increase toward the outer periphery. A permanent magnet inserted into each of the holes and having a substantially rectangular cross-sectional shape with respect to the insertion direction,
The permanent magnet is formed by a plurality of types of magnetic materials different relatively coercive force, when inserted into the magnetic insertion hole, a high magnetic coercive force is disposed on the stator side, by the permanent magnet The center of the magnetic pole formed is shifted stepwise in the circumferential direction of the rotor core in the stacking direction of the rotor core, and the magnetic body having a high coercive force is adjacent to the stacking direction of the rotor core. It is formed in the thickness which can contact with the magnetic body with high coercive force provided in the said permanent magnet (Claim 1).

In addition, the rotor of the rotating electrical machine of the present invention includes a rotor core and a pair of magnetic cores that are provided in the rotor core with a certain interval in the circumferential direction and the opposing distances gradually increase toward the outer periphery. A permanent magnet that is inserted into the body insertion hole and has a substantially rectangular cross-section in the insertion direction. The permanent magnet is formed of a plurality of types of magnetic bodies having relatively different coercive forces. The formed magnetic pole is configured such that the center thereof is shifted stepwise in the circumferential direction of the rotor core in the stacking direction of the rotor core, and further, the surface on which the stepwise shift is formed. A magnetic body having a high coercive force is disposed at the end on the side ( claim 4 ).

  The rotating electrical machine of the present invention is characterized by using the above-described rotor.

  According to the rotor of the rotating electrical machine of the present invention (Claim 1), since the high coercive force portion is arranged on the stator coil side, the influence of the demagnetizing field due to the magnetomotive force generated from the stator coil can be reduced. Thus, demagnetization of the permanent magnet can be suppressed. Further, since an expensive high-coercivity magnetic body is used as a part of the permanent magnet, the material cost is not significantly increased. Furthermore, since the demagnetization resistance can be increased without increasing the outer shape of the permanent magnet, the rotor is not increased in size.

  Further, according to the rotor of the rotating electrical machine of the present invention (Claim 3), the high coercive force portion is provided on the surface side where the deviation is formed in the rotor core where the stepwise deviation of the magnetic pole is formed. Since it is arrange | positioned at an edge part, the demagnetization in the surface in which the said shift | offset | difference which is easy to demagnetize a permanent magnet is formed can be suppressed.

  Moreover, according to the rotating electrical machine of the present invention, since the above-described rotor is used, a significant increase in material cost can be suppressed and an increase in size is not caused.

FIG. 2 is a diagram showing a configuration of a rotor according to a first embodiment of the present invention, and is an enlarged view of a region I in FIG. A diagram schematically showing a permanent magnet motor Rotor side view The perspective view which shows the structure of a permanent magnet typically Diagram showing the arrangement of permanent magnets Sectional drawing along the VI-VI line of FIG. FIG. 1 equivalent figure by 2nd Embodiment of this invention. 4 equivalent diagram FIG. 6 is a sectional view taken along line IX-IX in FIG. FIG. 1 equivalent view according to the third embodiment of the present invention. 4 equivalent diagram FIG. 5 equivalent view according to the fourth embodiment of the present invention. 4 equivalent diagram FIG. 6 is a sectional view taken along line XIV-XIV in FIG. FIG. 4 equivalent view according to the fifth embodiment of the present invention. 6 equivalent diagram FIG. 1 equivalent view 1 according to a sixth embodiment of the present invention Figure 2 equivalent figure 2 Figure 1 equivalent figure 3 4 equivalent diagram 1 Figure 1 equivalent part 4 4 equivalent diagram 2 FIG. 1 equivalent view 1 according to a seventh embodiment of the present invention Figure 2 equivalent figure 2 Figure 1 equivalent figure 3 Figure 1 equivalent figure 4

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)
Hereinafter, a first embodiment in which the present invention is applied to an inverter-driven permanent magnet motor used in an electric vehicle, a hybrid vehicle, and the like will be described with reference to FIGS.

  FIG. 2 is a diagram showing an outline of the permanent magnet motor 1. The permanent magnet motor 1 is composed of a stator 2 and a rotor 3 arranged on the inner peripheral side of the stator 2. In the stator 2, a U-phase coil 5, a V-phase coil 6, and a W-phase coil 7, which are multiple-phase, for example, three-phase coils, are wound around a stator core 4. The stator core 4 has a cylindrical shape integrally formed by laminating a plurality of annular core pieces obtained by punching a silicon steel plate with a press, for example, on the inner peripheral surface of the stator core 4, A plurality of, for example, 48 stator slots 8 for forming the U-phase coil 5, V-phase coil 6 and W-phase coil 7 are formed. Hereinafter, the U-phase coil 5, the V-phase coil 6, and the W-phase coil 7 are collectively referred to as a stator coil.

  The rotor 3 includes, for example, a rotor core 9 formed by laminating a plurality of core pieces formed in an annular shape by punching a silicon steel plate with a press, and a rotating shaft 10 provided on an inner peripheral portion of the rotor core 9. And have. The rotor 3 is rotatably arranged with a slight gap (air gap) between the outer peripheral surface thereof and the inner peripheral surface of the stator 2. The rotary shaft 10 passes through the rotor core 9 in the stacking direction of the core material, and is fixed to the rotor core 9.

  In the outer peripheral portion of the rotor core 9, a plurality of pairs of magnetic slots 11 (magnetic insertion holes referred to in the present invention) whose opposing distances sequentially increase toward the outer periphery, for example, eight pairs, predetermined in the circumferential direction. The rotor core 9 is penetrated in the lamination direction (axial direction) of the iron core material. These eight pairs of magnetic slots 11 are provided at equal intervals, and are arranged in a V shape when viewed from the inner peripheral side of the rotor 3.

  Permanent magnets 12 made of a magnetic material containing a rare earth element such as neodymium are inserted into the magnetic slots 11 respectively. The permanent magnet 12 is arranged so that the same pole is located on the outer peripheral side of the rotor 3 in the pair of magnetic body slots 11, and the polarity located on the outer peripheral side is in the magnetic body slot 11 adjacent in the circumferential direction. They are arranged so as to be opposite to each other. Thereby, in the circumferential direction of the rotor 3, magnetic poles (N poles or S poles) having different polarities are alternately formed.

  The rotor 3 having such a configuration, when considered as the permanent magnet motor 1, is formed with a magnetic concave portion (d axis) in which magnetic flux does not easily pass and a magnetic convex portion (q axis) in which magnetic flux easily passes. The d-axis has a high magnetic resistance and the q-axis has a low magnetic resistance. A reluctance torque is generated by this change in magnetic resistance, and torque is also generated by a magnetic attractive force and a magnetic repulsive force between the permanent magnet 12 and the magnetic poles of the stator 2, so that the rotor 3 rotates.

  FIG. 3 is a side view of the rotor 3 viewed from the side. In the magnetic material slot 11 provided in the rotor 3, the center position of the rotor 3 with respect to the axial direction is shifted stepwise in the circumferential direction of the rotor 3. Therefore, the magnetic poles (N poles in FIG. 3) generated by the permanent magnets 12 inserted into the magnetic material slots 11 are also shifted stepwise in the circumferential direction of the rotor 3. In other words, the rotor 3 is provided with a stepwise circumferential magnetic pole shift, that is, a stepped skew, in the axial direction thereof. FIG. 3 schematically shows one of the magnetic poles generated by the permanent magnet 12 for the sake of simplicity.

  FIG. 1 is an enlarged view of the region I shown in FIG. 2 and shows a state where the permanent magnet 12 is housed in the magnetic material slot 11. A bridge portion 13 is formed between the pair of magnetic material slots 11 in which the permanent magnets 12 are accommodated. The bridge portion 13 is formed with a narrow width in order to achieve both the strength that is not broken by the centrifugal force applied to the permanent magnet 12 during rotation and the reduction of leakage magnetic flux that travels through the rotor core 9. Further, by reducing the width, the distance between adjacent permanent magnets 12 is shortened, the magnetic flux flowing through the bridge portion 13 is saturated, and the magnetic flux generated from the stator coil flows between the magnetic material slots 11. Suppressed.

  The bridge portion 13 has a pressing portion 14 that protrudes toward the magnetic material slot 11. When the permanent magnet 12 is inserted into the magnetic material slot 11, the permanent magnet 12 is positioned by abutting against the pressing portion 14. Further, a narrow tip portion 15 is formed between the outer peripheral end of the magnetic material slot 11 and the outer periphery of the rotor core 9, and the magnetic material slot 11 side is provided on the tip portion 15 side. A pressing portion 15 a that protrudes to hold the permanent magnet 12 is formed. The tip portion 15 limits the leakage magnetic flux of the permanent magnet 12.

Next, the permanent magnet 12 will be described in detail.
The permanent magnet 12 includes a low coercive force portion 12a formed of a magnetic material having a relatively low coercive force, and a high coercive force portion formed of a magnetic material having a relatively high coercive force with respect to the low coercive force portion 12a. 12b. Specifically, the magnetic material forming the low coercive force portion 12a is formed of a neodymium magnet having a coercive force of about 1000 to 1600 k [A / m], and the magnetic material forming the high coercive force portion 12b is For example, it is formed of a neodymium magnet whose coercive force is increased to about 2400 to 2700 k [A / m] by adding dysprosium or the like. The low coercive force portion 12a indicates a portion having a relatively low coercive force with respect to the high coercive force portion 12b, and the magnitude of the coercive force itself of the low coercive force portion 12a is the same as the conventional one. .

  The permanent magnet 12 is housed in the magnetic body slot 11 in a state where the low coercive force portion 12a and the high coercive force portion 12b are laminated and integrally formed with each other. In this case, the outer shape of the permanent magnet 12 is formed in the same size as that conventionally used. Such a permanent magnet 12 has a substantially rectangular cross-sectional shape, and a high coercive force portion 12b is disposed on the side where the pair of magnetic material slots 11 face each other at the end in the short direction. That is, the high coercive force portion 12 b is provided on the inner surface of the V shape formed by the pair of magnetic body slots 11. Therefore, the permanent magnet 12 has an appearance as shown in FIG.

  By the way, in this embodiment, as shown in FIG. 5, the center positions of the permanent magnets 12 (the permanent magnet 12 indicated by the solid line and the permanent magnet 12 indicated by the broken line) adjacent to each other in the stacking direction of the rotor core 9 are the rotor. It is shifted in the circumferential direction of the iron core 9. In FIG. 5, the magnetic material slot 11 is omitted for simplification of description, but it is formed by a magnetic pole formed by a pair of permanent magnets 12 shown by a solid line and a pair of permanent magnets 12 shown by a broken line. Thus, the rotor 3 is provided with a stepwise skew in the axial direction (see FIG. 3).

  At this time, as shown in FIG. 6, the thickness T of the high coercive force portion 12b of the permanent magnet 12 is such that the permanent magnets 12 adjacent to each other in the axial direction on the skew surface 9a where the width W of the permanent magnet 12 is apparently narrowed. The thickness is set such that the high coercive force portion 12b can be contacted. That is, the width W of the permanent magnet 12 is apparently narrow, and the short side in the sectional view of the permanent magnet 12 is formed on the side of the skew surface 9a where the stepwise shift is easily affected by the magnetomotive force from the stator coil. In the direction, the high coercive force portion 12b formed of a magnetic material having a high coercive force is arranged so that at least a part of each other is in contact with the rotor 3 and located on the outer peripheral side (stator 2 side) of the rotor 3. Has been.

  Further, as shown in FIG. 1, the permanent magnet 12 is thick so that the high coercive force portion 12b and the pressing portion 14 are in contact with each other, that is, the pressing portion 14 and the low coercive force portion 12a are not in contact with each other. T is set. Note that the thickness T of the high coercive force portion 12b may be appropriately adjusted according to the magnitude of the magnetic pole shift in the circumferential direction of the rotor 3 (so-called skew angle), the shape of the magnetic material slot 11, and the like.

  The rotor 3 provided with such permanent magnets 12 is combined with the stator 2 to constitute the permanent magnet motor 1. At this time, in the rotor 3 provided with the two-stage skew, for example, two rotor blocks having the same shape and having a half length of the entire length are manufactured, and they are laminated by shifting them in the circumferential direction. Thus, the rotor 3 is formed.

Next, operations and effects of the permanent magnet motor 1 having the above-described configuration will be described.
Magnetomotive force generated from the U-phase coil 5, V-phase coil 6, and W-phase coil 7 wound around the external stator 2 acts on the permanent magnet 12 provided in the rotor 3 during actual operation. . At this time, the magnetomotive force generated when a current flows through the stator coil is applied in a direction opposite to the magnetization direction of the permanent magnet 12, and if the magnetomotive force exceeds a certain magnitude, the permanent magnet 12 Irreversibly demagnetized. As a result, the performance of the permanent magnet motor 1 may be deteriorated such as a decrease in torque performance.

  Therefore, in the rotor 3, the permanent magnet 12 is formed by the low coercive force portion 12a and the high coercive force portion 12b having a higher coercive force than the low coercive force portion 12a, and is on the side of the stator 2 that is the source of magnetomotive force. The high coercive force portion 12b is disposed on the surface. Since the magnetic body forming the high coercive force portion 12b has a high resistance to demagnetization, the high coercive force portion 12b is disposed at a portion that is easily affected by the magnetomotive force generated from the stator coil. It becomes difficult to demagnetize even with a demagnetizing field, and demagnetization of the permanent magnet 12 can be reduced. Therefore, it is possible to provide the rotor 3 having high demagnetization resistance.

  The permanent magnet 12 has a structure in which the high coercive force portion 12b is disposed on a part thereof, that is, the surface facing the stator coil, so that, for example, the surface and end face of the permanent magnet 12 can be easily demagnetized. Demagnetization can be increased. In addition, it is possible to reduce the consumption of the magnetic material having a high coercive force, and it is possible to suppress a significant increase in material cost.

  Since the permanent magnet 12 is formed by laminating the low coercive force portion 12a and the high coercive force portion 12b, the manufacturing process is not complicated, and a significant increase in material cost can be suppressed. Further, since the permanent magnet 12 is formed to have the same shape without changing the size of the conventional configuration, the characteristics as a magnetic pole are not deteriorated, and the rotor 3 is large. It does not become. Therefore, there is no significant increase in manufacturing cost.

  A high coercive force portion 12b is disposed at the end of the permanent magnet 12 in the short-side direction and on the skew surface 9a side in the sectional view of the permanent magnet 12, and the thickness T of the high coercive force portion 12b is set to a skew angle. Accordingly, at least a part of the mutual high coercive force portion 12b is in contact with each other between the adjacent permanent magnets 12 on the skew surface 9a, so that the portion where the width W of the permanent magnet 12 is apparently narrowed is set. Magnetic force becomes high and demagnetization can be reduced. Moreover, compared with the case where the whole permanent magnet 12 is manufactured with a magnetic material having a high coercive force, the amount of use of the magnetic material having a high coercive force is reduced, and it is possible to suppress a significant increase in material cost.

  Since the rotor 3 is formed by superimposing members having the same shape and having a half length of the entire length, even if a stepped skew is provided, a member having a different shape is not required. The process can be simplified.

  By using such a rotor 3, it becomes possible to improve the demagnetization resistance of the permanent magnet motor 1, and the highly reliable permanent magnet motor 1 can be provided. Further, the permanent magnet motor 1 is not increased in size. Further, since the demagnetization resistance of the permanent magnet 12 is increased, the value of the current flowing through the stator coil can be increased, and the performance of the permanent magnet motor 1 can be improved.

(Second Embodiment)
Next, a rotor according to a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is different from the first embodiment in that two high coercive force portions are provided in the permanent magnet provided in the rotor. The configuration of the permanent magnet motor of the second embodiment is almost the same as that of the first embodiment.

  FIG. 7 is a diagram illustrating a configuration of the rotor 3 according to the second embodiment. The permanent magnet 12 includes a low coercive force portion 12a and a high coercive force portion 12b as in the first embodiment. In addition, the magnetic body which forms the high coercive force portion 12b has a higher coercive force than the low coercive force portion 12a, as in the first embodiment.

  The high coercive force portion 12b of the permanent magnet 12 has both ends of a substantially rectangular short direction in a cross-sectional view, that is, the side on which the magnetic material slot 11 faces (inside the V shape) and the opposite side (outside the V shape) Is arranged. That is, as shown in FIG. 8, the permanent magnet 12 has a configuration in which the high coercive force portions 12b are arranged above and below the low coercive force portion 12a in the insertion direction. Accordingly, as shown in FIG. 9, both sides of the skew surface 9a where the width of the permanent magnet 12 is apparently narrowed are protected by the high coercive force portion 12b.

In this manner, the permanent magnet 12 is formed by the low coercive force portion 12a and the high coercive force portion 12b having a higher coercive force than the low coercive force portion 12a, whereby the stator wound around the stator 2 (see FIG. 2). An effect similar to that of the first embodiment can be obtained, for example, demagnetization due to magnetomotive force generated from the coil can be reduced.
In particular, in the second embodiment, the high coercive force portion 12b is arranged on the surface on the side facing the magnetic body slot 11 and the surface on the opposite side thereof, thereby demagnetizing the magnetic flux flowing on the inner peripheral side of the rotor 3. It can be reduced, and the resistance to demagnetization can be further increased.

(Third embodiment)
Next, the rotor by 3rd Embodiment of this invention is demonstrated based on FIG. 10 and FIG. The third embodiment is different from the first embodiment in that an outer peripheral hole portion is provided in the rotor core, and a high coercive force portion is provided in both longitudinal ends of the permanent magnet. The configuration of the permanent magnet motor of the third embodiment is almost the same as that of the first embodiment.

  FIG. 10 is a diagram illustrating a configuration of the rotor 3 according to the third embodiment. The rotor core 9 is provided with an outer peripheral hole portion 16 positioned inside the pair of magnetic material slots 11. The outer peripheral hole portion 16 restricts the flow of magnetic flux from the stator coil provided in the stator 2 (see FIG. 2) and the flow of magnetic flux from the permanent magnet 12. As a result, the deterioration of the characteristics of the permanent magnet motor 1 due to the occurrence of torque ripple, iron loss, or harmonics is prevented.

  The permanent magnet 12 housed in the rotor core 9 is composed of a low coercive force portion 12a and a high coercive force portion 12b as in the first embodiment. The high coercive force portion 12b is located at both ends in the longitudinal direction of the substantially rectangular permanent magnet 12 in a cross-sectional view, that is, at the outermost side and the innermost side of the rotor core 9 when inserted into the magnetic material slot 11. Is arranged. That is, as shown in FIG. 11, the permanent magnet 12 has a configuration in which the high coercive force portions 12b are arranged on the left and right sides of the low coercive force portion 12a in the insertion direction.

  The corners located on the outermost and innermost sides of the permanent magnet 12 are portions where the thickness of the permanent magnet 12 is apparently thin and the magnetic flux from the stator coil provided in the stator 2 is easy to pass through. It is. In other words, the corners of the permanent magnet 12 are easily affected by a demagnetizing field and are easily demagnetized. In the present embodiment, by arranging the high coercive force portion 12b at the corner, it is possible to improve the demagnetization resistance of the end portion of the permanent magnet 12, and the same effects as in the first embodiment can be obtained. .

  In particular, since the high coercive force portions 12b are arranged at both ends in the longitudinal direction in the sectional view of the permanent magnet 12, that is, at the end on the short side, it is possible to reduce the amount of use of the magnetic material having a high coercive force. It is possible to suppress a significant increase in cost.

(Fourth embodiment)
Next, the rotor by 4th Embodiment of this invention is demonstrated based on FIGS. 12-14. In 4th Embodiment, arrangement | positioning of the high coercive force part provided in the permanent magnet differs from 1st Embodiment. The configuration of the permanent magnet motor of the fourth embodiment is almost the same as that of the first embodiment, and a stepped skew is provided.

  FIG. 12 is a diagram illustrating a configuration of the rotor 3 according to the fourth embodiment. FIG. 12 schematically shows only the arrangement of the permanent magnets 12 for the sake of simplicity. In the rotor 3 provided with the stepped skew in this way, as described above, the skew surface 9a (see FIG. 14) is a portion where the width of the permanent magnet 12 is apparently narrow and easily demagnetized. is there.

  Therefore, in the fourth embodiment, as shown in FIGS. 13 and 14, the high coercive force portion 12 b of the permanent magnet 12 is inserted into the magnetic material slot 11 (see FIG. 2), that is, the stacking direction of the rotor core 9. In FIG. 4, the edge is provided at the end on the skew surface 9a side. In such a rotor 3, a member having the same shape having a length that is half of the entire length is first formed, and one of the members is inverted with respect to the axial direction, and is shifted from each other in the circumferential direction. Is formed.

Thus, by arranging the high coercive force portion 12b on the skew surface 9a side whose apparent width is narrow, the demagnetization due to the magnetomotive force generated from the stator coil can be reduced. Similar effects can be obtained.
In particular, in the fourth embodiment, since the high coercive force portion 12b is provided on the skew surface 9a, the demagnetization resistance of the portion where the width of the permanent magnet 12 is apparently narrow and easily demagnetized can be increased.
Further, since the rotor 3 is formed by reversing the members having the same shape, the work process can be simplified.

(Fifth embodiment)
Next, the rotor by 5th Embodiment of this invention is demonstrated based on FIG. 15 and FIG. The fifth embodiment is a modification of the fourth embodiment, and the arrangement of the high coercive force portions provided in the permanent magnet is different from that of the fourth embodiment.

  FIG. 15 is a perspective view showing the appearance of the permanent magnet 12 according to the fifth embodiment and corresponds to FIG. 13 of the fourth embodiment. FIG. 16 is a diagram schematically showing the arrangement of the permanent magnet 12 in the fourth embodiment. This corresponds to FIG. In the fifth embodiment, as shown in FIGS. 15 and 16, the high coercive force portions 12 b are provided at both ends in the insertion direction into the magnetic material slot 11 (see FIG. 2), that is, in the stacking direction of the rotor core 9. Yes. Thus, since the high coercive force portions 12b are provided at both ends in the insertion direction of the permanent magnet 12, that is, the skew surface 9a and the end surface side of the rotor 3, the skew surface 9a in which the width of the permanent magnet 12 is apparently narrowed. In addition, the demagnetization resistance at the end of the end face of the rotor 3 (surface opposite to the skew surface 9a) that is easily influenced by an external magnetomotive force can be increased. .

(Sixth embodiment)
Next, the rotor by 6th Embodiment of this invention is demonstrated based on FIGS. The sixth embodiment is a modification of the first to fifth embodiments described above, and the arrangement of the high coercive force portions provided in the permanent magnet is different from the above-described embodiments.

  For example, as shown in FIG. 17, the permanent magnet 12 may have a configuration in which a high coercive force portion 12 b is disposed on the outer periphery formed in a substantially rectangular shape in a cross-sectional view. In this case, the permanent magnet 12 may be formed by forming the low coercive force portion 12a and the high coercive force portion 12b separately and laminating them. Alternatively, as shown in FIG. 18, the permanent magnet 12 may be formed of a magnetic body having different coercive force continuously from the center side toward the outer peripheral side, that is, a magnetic body of a functionally gradient material. As a result, the same effects as those of the first to third embodiments can be obtained, such as demagnetization of the permanent magnet 12 being reduced. In FIG. 18, a configuration in which the coercive force continuously changes is schematically shown in two stages, a low coercive force portion 12a and a high coercive force portion 12b.

  Or if it is the rotor 3 in which the outer peripheral hole part 16 was provided, as shown in FIG.19 and FIG.20, let the permanent magnet 12 be the inner surface of the magnetic body slot 11 of the low coercive force part 12a, and the surface on the opposite side. It is good also as a structure which arrange | positions the high coercive force part 12b other than the site | part corresponding to. Thereby, the demagnetization of the part which is easy to demagnetize, such as the corner | angular part of the permanent magnet 12, the skew surface 9a side, and the end surface side of the rotor 3, can be reduced. Further, since the high coercive force portion 12b is not disposed on the side where the magnetic flux is restricted by the outer peripheral hole portion 16, that is, the inner side and the outer side of the magnetic material slot 11, an increase in material cost can be suppressed.

  Alternatively, as shown in FIGS. 21 and 22, the entire outer periphery of the low coercive force portion 12a may be covered with the high coercive force portion 12b. Thereby, even if it is the case of the rotor 3 in which the outer peripheral hole part 16 is not provided, the influence of the magnetomotive force with respect to the permanent magnet 12 is reduced with respect to all directions, and demagnetization resistance can be improved. In this case, the permanent magnet 12 may be formed of a functionally gradient material having different coercive forces sequentially from the center of the permanent magnet 12 toward the outer peripheral side. This eliminates the need for assembling a plurality of high coercive force portions 12b having different shapes to the low coercive force portion 12a, thereby improving work efficiency and reducing the number of parts of the permanent magnet 12, thereby reducing the manufacturing cost. Increase can be suppressed.

(Seventh embodiment)
Next, a rotor according to a seventh embodiment of the present invention will be described with reference to FIGS. In 7th Embodiment, the shape of the high coercive force part provided in the permanent magnet differs from each above-described embodiment.

  In the first to sixth embodiments described above, the permanent magnet 12 has a substantially rectangular cross-sectional shape. In the case of such a cross-sectional shape, when the permanent magnet 12 is housed in the magnetic material slot 11, for example, in the permanent magnet 12 of the first embodiment, the high coercive force portion 12b is disposed outside at the V time, or in the fourth embodiment. In the permanent magnet 12 of the form, the high coercive force portion 12b may be disposed at the end opposite to the skew surface 9a, and the permanent magnet 12 may be stored in a wrong direction in the manufacturing process.

  Therefore, in the present embodiment, the cross-sectional shape is changed in order to prevent erroneous insertion of the permanent magnet 12. For example, as shown in FIG. 23, a chamfered portion 12 c is provided at one of the four corners of the permanent magnet 12. For this reason, the chamfered portion 12c serves as a guide in the insertion direction, and erroneous insertion of the permanent magnet 12 can be prevented. In this case, the chamfered portion 12c is preferably asymmetric with respect to the center line L1 in the longitudinal direction and the center line L2 in the short direction of the permanent magnet 12. By providing the chamfered portion 12c asymmetrically left and right or up and down, for example, in FIG. 23, it can be confirmed that the chamfered portion 12c is inserted in the correct direction if the chamfered portion 12c is arranged on the outer peripheral side of the rotor core 9 at the time of insertion. Efficiency can be improved. Further, since the chamfered portion 12c is as close as possible to the tip portion 15, for example, the left permanent magnet 12 cannot be inserted into the right slot, and erroneous insertion can be prevented.

  Further, as shown in FIG. 24, the magnetic body slot 11 may be shaped to match the chamfered portion 12 c of the permanent magnet 12. In the case of the permanent magnet 12 as in the first embodiment, the high coercive force portion 12b is formed symmetrically with respect to the insertion direction. Therefore, in FIGS. 23 and 24, for example, the right permanent magnet 12 can be obtained by inverting the left permanent magnet 12 with respect to the insertion direction. That is, it becomes possible to insert the permanent magnet 12 having the same shape into the left and right magnetic slots 11 while preventing the right and left from being mixed up, thereby improving work efficiency.

  Alternatively, as shown in FIG. 25, a convex portion 12d is provided in a part of the permanent magnet 12, and a concave portion is provided in the magnetic body slot 11 at a position corresponding to the convex portion 12d, thereby preventing erroneous insertion. Good. In addition, as shown in FIG. 26, it is possible to prevent erroneous insertion by providing a concave portion 12e in a part of the permanent magnet 12 and providing a convex portion in the magnetic body slot 11 at a position corresponding to the concave portion 12e. . Of course, it is good also as a structure which provides both the convex part 12d and the recessed part 12e. Thereby, even if it is the structure which arrange | positions the high coercive force part 12b in the skew surface 9a like 4th Embodiment, for example, since it cannot insert in a reverse direction, incorrect insertion can be prevented.

In this case, the convex portion 12d or the concave portion 12e may be provided on the low coercive force portion 12a side. That is, by forming the convex portion 12d or the concave portion 12e on the relatively inexpensive low coercive force portion 12a, it is possible to prevent the magnetic material of the expensive high coercive force portion 12b from being wasted.
As described above, the permanent magnet 12 is formed without being complicated by forming it asymmetric with respect to the center line L1 or L2 or by providing irregularities in the permanent magnet 12 and the magnetic material slot 11. Can be prevented from being erroneously inserted, and work efficiency can be improved.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the gist thereof. For example, the present invention can be modified or expanded as follows.

  Although an example in which the present invention is applied to an inverter-driven three-phase permanent magnet type electric motor has been shown, the number of phases and the driving method are not limited to this. For example, the present invention can be applied to general rotating electrical machines using permanent magnets such as an inner rotor type or outer rotor type electric motor or generator. Of course, you may apply to the rotary electric machine used for purposes other than for vehicles.

Although the example in which the present invention is applied to the rotor 3 provided with the two-step skew is shown, the present invention may be applied to the rotor provided with the three-step skew or more.
In each embodiment excluding the fourth embodiment, the present invention may be applied to a rotor that is not provided with a stepped skew. Even in this case, the demagnetization of the permanent magnet 12 can be reduced by disposing the high coercive force portion 12b on the stator 2 side.

  You may make it form the permanent magnet 12 of 1st-4th embodiment with the magnetic body of a functionally gradient material. Or in each embodiment, it is good also as a structure using three or more types of magnetic bodies from which a coercive force mutually differs. For example, in the case of the rotor provided with the outer peripheral hole portion 16, the coercive force is lower than that of the high coercive force portion 12b and lower than that of the low coercive force portion 12a on a part of the side facing the outer peripheral hole portion 16. A configuration in which a magnetic material having a high height is disposed is conceivable.

  In the drawings, 1 is a permanent magnet motor (rotary electric machine), 2 stator, 3 is a rotor, 9 is a rotor core, 9a is a skew surface (a surface on which a stepwise deviation is formed), 12 is a permanent magnet, 12a shows a low coercive force portion, and 12b shows a high coercive force portion.

Claims (10)

A plurality of rotor cores and a plurality of magnetic cores inserted into a pair of magnetic body insertion holes each having a constant distance in the circumferential direction of the rotor core, the opposing distances of which gradually increase toward the outer circumference. A permanent magnet having a substantially rectangular shape,
The permanent magnet is formed of a plurality of types of magnetic bodies having relatively different coercive forces , and when inserted into the magnetic body insertion hole, a magnetic body having a high coercive force is disposed on the stator side ,
The magnetic pole formed by the permanent magnet has its center shifted stepwise in the circumferential direction of the rotor core in the stacking direction of the rotor core,
A magnetic body having a high coercive force is formed in a thickness that allows contact with a magnetic body having a high coercive force provided in the permanent magnets adjacent to each other in the stacking direction of the rotor core . Rotor. The rotor of a rotating electrical machine according to claim 1, wherein the permanent magnet has a magnetic body having a high coercive force disposed on a side opposite to the stator in a cross-sectional view. The permanent magnet is a portion where the permanent magnets adjacent to each other in the stacking direction of the rotor core overlap with each other at the end in the short direction and the magnetic bodies having high coercive force in the entire longitudinal direction. The rotor for a rotating electrical machine according to claim 1, wherein the rotor is a rotating electrical machine. A rotor core and a plurality of rotor cores are provided in the circumferential direction with a certain interval in the circumferential direction, and are inserted into a pair of magnetic body insertion holes whose opposing distances gradually increase toward the outer circumference, respectively, and a cross section with respect to the insertion direction A permanent magnet having a substantially rectangular shape,
The permanent magnet is formed of a plurality of types of magnetic bodies having relatively different coercive forces,
The magnetic pole formed by the permanent magnet is configured such that the center thereof is gradually shifted in the circumferential direction of the rotor core in the stacking direction of the rotor core,
Further, a rotor of a rotating electrical machine, wherein a magnetic body having a high coercive force is disposed at an end portion on the surface side where the stepwise deviation is formed. 5. The rotor of a rotating electrical machine according to claim 4, wherein when the permanent magnet is inserted into the magnetic body insertion hole, a magnetic body having a high coercive force is disposed on the stator side. 6. The rotating electrical machine according to claim 4, wherein the permanent magnet is provided with a magnetic material having a high coercive force at a portion serving as an end surface of the rotor when inserted into the magnetic material insertion hole. Rotor. 7. The rotating electrical machine according to claim 1, wherein the shape of the permanent magnet is asymmetric with respect to a center line in a longitudinal direction or a short direction in a cross-sectional view. Rotor. The permanent magnet is provided with a convex portion at a part of its outer edge in a cross-sectional view, and the magnetic material insertion hole is provided with a concave portion corresponding to the convex portion. A rotor for a rotating electrical machine according to any one of claims 7 to 10. 9. The permanent magnet is provided with a recess in a part of its outer edge in a sectional view, and the magnetic material insertion hole is provided with a projection corresponding to the recess. The rotor of the rotary electric machine as described in any one of the above. A rotating electrical machine using the rotor of the rotating electrical machine according to any one of claims 1 to 9.

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