JP2016226218A - Permanent magnet embedded rotor for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet embedded rotor for a rotary electric machine capable of improving a performance of the rotary electric machine.SOLUTION: A rotor core 2 is formed with: a d-axis core part 2D which is positioned radially outsides relatively to a permanent magnet 10; q-axis core parts 2Q that are arranged side by side in a circumferential direction relatively to the d-axis core part 2D; continuous slits 31 and 32 which extend towards an opposite side of the permanent magnet 10 in the circumferential direction continuously to flux barriers 21 and 22 and have widths W31 and W32 in a radial direction being narrower than the flux barriers 21 and 22; independent slits 41 and 42 which extend in the circumferential direction at positions separated radially to the outside relatively to the continuous slits 31 and 32 and oppose the continuous slits 31 and 32 in the radial direction; and a plurality of bridges 51 and 52 which are arranged side by side radially inside and outside of the independent slits 41 and 42 between the continuous slits 31 and 32 and an outer edge 2E of the rotor core 2, couple and support the d-axis core part 2D and the q-axis core parts 2Q.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a permanent magnet embedded rotor of a rotating electrical machine.

  Patent Document 1 discloses a conventional permanent magnet embedded rotor (hereinafter referred to as “rotor”) of a rotating electrical machine. The rotor includes a rotor core and a plurality of permanent magnets. In the rotor core, a plurality of accommodation holes are formed side by side in the circumferential direction. The permanent magnet is accommodated and held in each accommodation hole.

  More specifically, the rotor core is formed with a plurality of sets of receiving holes that are divided into two in the circumferential direction. A permanent magnet having the same magnetic pole is held in each group of receiving holes.

  In this rotor, a d-axis and a q-axis are set by permanent magnets. The d-axis is the direction of the magnetic flux generated by the magnetic pole, and in Patent Document 1, it is the central axis between the permanent magnets of the same magnetic pole. The q-axis is an axis that is electrically and magnetically orthogonal to the d-axis. In Patent Document 1, it is the central axis between permanent magnets of different magnetic poles.

  The accommodation hole has a flux barrier. The flux barrier is formed by a gap between the end surface of the permanent magnet on the q-axis side and suppresses short-circuiting of the magnetic flux of the permanent magnet.

  In this rotor, a centrifugal force acts on the rotor core when the rotating electrical machine operates, and stress is generated in the rotor core. Here, the region sandwiched between the housing holes divided into two in the circumferential direction in the rotor core is a region located on the inner side in the radial direction with respect to the housing holes and located on the outer side in the radial direction with respect to the housing holes. The connection part which connects the area | region to perform is comprised. In this rotor, such a connecting portion reduces the maximum stress acting on the periphery of each accommodation hole and flux barrier in the rotor core.

JP 2008-211194 A

  By the way, in order to improve the performance of the rotating electrical machine, it is conceivable to increase the magnet torque by increasing the mass of the permanent magnet included in the rotor. In this case, due to the increase in the mass of the permanent magnet, the centrifugal force acting on the rotor core increases when the rotating electrical machine operates, and stress concentration is likely to occur around the accommodation hole and the flux barrier in the rotor core. For this reason, the maximum rotational speed of the rotor is set so that the maximum stress generated in the rotor core does not exceed the allowable range. That is, it is difficult to achieve both an increase in magnet torque and an increase in maximum rotational speed.

  In this respect, in the conventional rotor described above, it is conceivable to increase the width of the connecting portion in accordance with an increase in the mass of the permanent magnet. However, in this case, there is a problem that leakage magnetic flux passing through the connecting portion increases, and magnet torque cannot be generated efficiently. Further, in this case, there is a problem that the d-axis inductance Ld increases, the difference in inductance between the d-axis and the q-axis decreases, and the reluctance torque decreases.

  As a result, it is difficult for the conventional rotor described above to improve the performance of the rotating electrical machine.

  The present invention has been made in view of the above-described conventional situation, and an object to be solved is to provide a permanent magnet embedded rotor of a rotating electrical machine that can improve the performance of the rotating electrical machine.

The permanent magnet embedded rotor of the rotating electrical machine of the present invention includes a rotor core in which a plurality of accommodation holes are formed side by side in the circumferential direction, and a permanent magnet that is accommodated and held in each of the accommodation holes,
In the permanent magnet embedded rotor of the rotating electrical machine in which the d axis and the q axis are set by the permanent magnet,
The accommodation hole is formed by a gap between the permanent magnet and the end surface on the q-axis side, and has a flux barrier that suppresses short-circuiting of the magnetic flux of the permanent magnet,
In the rotor core,
A d-axis core portion located radially outside the permanent magnet;
A q-axis core portion arranged in the circumferential direction with respect to the d-axis core portion;
A continuous slit extending continuously from the flux barrier toward the opposite side of the permanent magnet in the circumferential direction, and having a radial width smaller than the flux barrier,
An independent slit extending in the circumferential direction at a position spaced outward in the radial direction with respect to the continuous slit, and facing the continuous slit in the radial direction;
Between the continuous slit and the outer peripheral edge of the rotor core, it is arranged side by side on the inner side and the outer side in the radial direction with respect to the independent slit, and connects and supports the d-axis core part and the q-axis core part. A plurality of bridges are formed.

  In the rotor of the present invention, the stress generated around the accommodation hole and the flux barrier in the rotor core is in the vicinity of the permanent magnet due to the continuous slit having a smaller radial width than the flux barrier, independent slits, and a plurality of bridges. Distributed from. That is, in this rotor, a plurality of narrow beam-shaped bridges are arranged in parallel around the flux barrier, and each bridge connects and supports the d-axis core part and the q-axis core part. For this reason, when each bridge is similarly deformed, the stress acting on the periphery of the accommodation hole and the flux barrier can be distributed to each bridge. As a result, in this rotor, the maximum stress acting on the periphery of the accommodation hole and the flux barrier in the rotor core can be reliably reduced. Thus, in this rotor, even if the mass of the permanent magnet is increased to increase the magnet torque and the maximum rotational speed of the rotor is set high, the maximum stress generated in the rotor core is difficult to exceed the allowable range. For this reason, it becomes easy to achieve both an increase in magnet torque and an increase in maximum rotational speed.

  Accordingly, in this rotor, when the connecting portion is configured like the conventional rotor described above, the width of the connecting portion is reduced, thereby increasing the leakage magnetic flux passing through the connecting portion, d-axis inductance. An increase in Ld can also be suppressed. On the other hand, by eliminating the connecting portion described above, the leakage magnetic flux passing through the connecting portion can be eliminated, and the d-axis inductance Ld can be reduced. Further, in this rotor, a diaphragm is provided in the core width between the magnetic poles of the permanent magnet by the continuous slit, the independent slit and each bridge, and the diaphragm length can be increased while maintaining the diaphragm width. Leakage magnetic flux can also be reduced. As a result, in this rotor, the magnet torque can be generated efficiently and the decrease in the reluctance torque can be suppressed.

  Therefore, in the permanent magnet embedded rotor of the rotating electrical machine of the present invention, the performance of the rotating electrical machine can be improved. Moreover, in this rotor, since the radial width of the continuous slit is smaller than that of the flux barrier, the continuous slit hardly influences the action of the flux barrier that suppresses short-circuiting of the magnetic flux of the permanent magnet.

  The flux barrier is preferably composed of a first flux barrier located on one q-axis side of the permanent magnet and a second flux barrier located on the other q-axis side of the permanent magnet. The continuous slit is continuous with the first flux barrier and extends toward the opposite side of the permanent magnet in the circumferential direction. The continuous slit is continuous with the second flux barrier and faces away from the permanent magnet in the circumferential direction. It is desirable that the second continuous slit extends. The independent slit extends in the circumferential direction at a position spaced radially outward with respect to the first continuous slit, and is in the radial direction with respect to the first continuous slit and the second continuous slit facing the first continuous slit in the radial direction. It is desirable that the second independent slit extends in the circumferential direction at a position separated from the outer side of the first slit and faces the second continuous slit in the radial direction. The bridge includes a first bridge arranged between the first continuous slit and the outer peripheral edge side by side in the radial direction with respect to the first independent slit, and the second continuous slit and the outer peripheral edge. Between the second independent slits, it is desirable that the second bridges are arranged side by side on the inner side and the outer side in the radial direction.

  In this case, in this rotor, since the connecting portion described above is eliminated and the housing hole that is not divided into two has the first and second flux barriers, there is no leakage magnetic flux passing through the connecting portion, and the d-axis inductance Ld is reduced. Reduced. In this rotor, a plurality of narrow beam-shaped first and second bridges are arranged in parallel around the first and second flux barriers, and each first bridge has a d-axis core portion and one q-axis core portion. The second bridges connect and support the d-axis core part and the other q-axis core part. For this reason, when each 1st, 2 bridge deform | transforms similarly, the stress which acts on the circumference | surroundings of an accommodation hole and the 1st, 2nd flux barrier can be disperse | distributed to each 1st, 2 bridge. As a result, in this rotor, the maximum stress acting on the periphery of the accommodation hole and the first and second flux barriers in the rotor core can be reliably reduced, so that the performance improvement of the rotating electrical machine can be realized with certainty.

  The circumferential end of the continuous slit and the circumferential end of at least one independent slit are preferably rounded. According to this configuration, stress concentration at the end of each bridge can be relaxed.

  It is desirable that a plurality of independent slits are formed, the lengths of the individual slits are substantially equal in the circumferential direction, and the continuous slits and the individual slits are shifted in the circumferential direction. It is desirable that the continuous slit and the independent slit have different lengths in the circumferential direction. It is desirable that the continuous slit and the independent slit have a longer circumferential length as they are radially outer. It is desirable that the continuous slit and the independent slit have different radial widths. Each bridge desirably has a different radial width.

  According to these configurations, the arrangement of the continuous slits, the independent slits, and the bridges forming the diaphragm can be optimized as appropriate according to the specifications and required performance of the rotor. It is possible to set, and the leakage magnetic flux passing through each bridge can be effectively reduced.

  Each bridge is preferably bent in the circumferential direction. According to this configuration, when the centrifugal force acts on the rotor core, the tensile stress acting on each bridge can be relieved by deforming so that the bent portion of each bridge is stretched.

  In the above case, each bridge desirably extends outward in the radial direction as it is separated from the permanent magnet in the circumferential direction. According to this configuration, when the centrifugal force acts on the rotor core, the extension amount of each bridge becomes small, so that the tensile stress acting on each bridge can be further relaxed. In particular, when each bridge extends while curving in a substantially S shape, the tensile stress acting on each bridge can be further relaxed.

  It is desirable that the bridges have substantially the same length in the circumferential direction and the same width in the radial direction. According to this configuration, the stress acting on the periphery of the accommodation hole and the flux barrier can be evenly distributed to each bridge.

A permanent magnet buried type rotor of another rotating electrical machine of the present invention includes a rotor core in which a plurality of accommodation holes are formed side by side in the circumferential direction, and a permanent magnet that is accommodated and held in each of the accommodation holes,
In the permanent magnet embedded rotor of the rotating electrical machine in which the d axis and the q axis are set by the permanent magnet,
The accommodation hole is formed by a gap between the permanent magnet and the end surface on the q-axis side, and has a flux barrier that suppresses short-circuiting of the magnetic flux of the permanent magnet,
In the rotor core,
A d-axis core portion located radially outside the permanent magnet;
A q-axis core portion arranged in the circumferential direction with respect to the d-axis core portion;
A continuous slit extending continuously from the flux barrier toward the opposite side of the permanent magnet in the circumferential direction and not protruding outward in the radial direction from the flux barrier;
An independent slit extending in the circumferential direction at a position spaced outward in the radial direction with respect to the continuous slit, and facing the continuous slit in the radial direction;
Between the continuous slit and the outer peripheral edge of the rotor core, it is arranged side by side on the inner side and the outer side in the radial direction with respect to the independent slit, and connects and supports the d-axis core part and the q-axis core part. A plurality of bridges are formed.

  In another rotor of the present invention, the stress generated around the accommodation hole and the flux barrier in the rotor core is caused by a continuous slit that does not protrude radially outward from the flux barrier, an independent slit, and a plurality of bridges. Dispersed from the vicinity of the permanent magnet. That is, in this rotor, a plurality of narrow beam-shaped bridges are arranged in parallel around the flux barrier, and each bridge connects and supports the d-axis core part and the q-axis core part. For this reason, when each bridge is similarly deformed, the stress acting on the periphery of the accommodation hole and the flux barrier can be distributed to each bridge. As a result, in this rotor, the maximum stress acting on the periphery of the accommodation hole and the flux barrier in the rotor core can be reliably reduced. Thus, in this rotor, even if the mass of the permanent magnet is increased to increase the magnet torque and the maximum rotational speed of the rotor is set high, the maximum stress generated in the rotor core is difficult to exceed the allowable range. For this reason, it becomes easy to achieve both an increase in magnet torque and an increase in maximum rotational speed.

  Accordingly, in this rotor, when the connecting portion is configured like the conventional rotor described above, the width of the connecting portion is reduced, thereby increasing the leakage magnetic flux passing through the connecting portion, d-axis inductance. An increase in Ld can also be suppressed. On the other hand, by eliminating the connecting portion described above, the leakage magnetic flux passing through the connecting portion can be eliminated, and the d-axis inductance Ld can be reduced. Further, in this rotor, a diaphragm is provided in the core width between the magnetic poles of the permanent magnet by the continuous slit, the independent slit and each bridge, and the diaphragm length can be increased while maintaining the diaphragm width. Leakage magnetic flux can also be reduced. As a result, in this rotor, the magnet torque can be generated efficiently and the decrease in the reluctance torque can be suppressed.

  Therefore, even with the permanent magnet embedded rotor of another rotating electrical machine of the present invention, the performance of the rotating electrical machine can be improved. In this rotor, the continuous slit does not protrude outward in the radial direction from the flux barrier, so that an independent slit is arranged between the continuous slit and the outer peripheral edge of the rotor core without increasing the radial distance. can do.

  The permanent magnet embedded rotor of the rotating electrical machine according to the present invention can improve the performance of the rotating electrical machine.

FIG. 1 is a schematic diagram illustrating a relationship between a permanent magnet embedded rotor of a rotating electrical machine according to a first embodiment and a stator. FIG. 2 is a partially enlarged view of the rotor according to the first embodiment. FIG. 3 is a partially enlarged view of the rotor according to the first embodiment. FIG. 4 is a partially enlarged view of the rotor according to the second embodiment. FIG. 5 is a partially enlarged view of the rotor according to the third embodiment. FIG. 6 is a partially enlarged view of the rotor according to the fourth embodiment. FIG. 7 is a partially enlarged view of the rotor according to the fifth embodiment. FIG. 8 is a partially enlarged view of the rotor according to the sixth embodiment. FIG. 9 is a partially enlarged view of the rotor according to the sixth embodiment. FIG. 10 is a partially enlarged view of the rotor according to the seventh embodiment.

  Examples 1 to 7 embodying the present invention will be described below with reference to the drawings.

Example 1
As shown in FIG. 1, the permanent magnet embedded rotor 1 (hereinafter referred to as “rotor 1”) of the rotating electrical machine of Example 1 is combined with a stator 9 to constitute the rotating electrical machine.

  The stator 9 has a cylindrical shape, and a plurality of teeth 8 are provided at equal intervals around the rotation axis X1 on the inner peripheral surface thereof. A coil 7 is wound around each tooth 8.

  The rotor 1 is disposed inside the stator 9. The rotor 1 includes a rotor core 2 and a plurality of permanent magnets 10. In the following description, “circumferential direction” refers to the circumferential direction of the rotor core 2, and “radial direction” refers to the radial direction of the rotor core 2.

  The rotor core 2 is formed by laminating a plurality (for example, several tens) of disk-shaped electromagnetic steel plates centering on the rotation axis X1. A rotating shaft 3 is fitted in the center of the rotor core 2. The rotor 1 is rotatably supported by a bearing of a housing (not shown) via a rotating shaft 3 in a state where a predetermined interval is secured between the outer peripheral edge 2E of the rotor core 2 and the teeth 8.

  In the rotor core 2, a plurality of receiving holes 20 are formed side by side in the circumferential direction. The respective accommodation holes 20 are arranged at equal intervals around the rotation axis X1. Each accommodation hole 20 extends long in the circumferential direction.

  The permanent magnet 10 is formed in a flat plate shape having a rectangular cross section. The permanent magnet 10 is housed and held in each housing hole 20 in a state substantially orthogonal to the radial direction of the rotor core 2. In the present embodiment, there are eight permanent magnets 10 and eight accommodating holes 20.

  The permanent magnet 10 is magnetized so that the magnetization direction is the thickness direction. Adjacent permanent magnets 10 are held in the receiving holes 20 so that poles arranged on the outer peripheral edge 2E side of the rotor core 2 are different from each other. For example, when the S pole of a certain permanent magnet 10 is arranged on the outer peripheral edge 2E side of the rotor core 2 and the N pole is arranged on the rotation axis X1 side, the N pole of the permanent magnet 10 adjacent to the permanent magnet 10 is The outer peripheral edge 2E side of the rotor core 2 is disposed, and the south pole is disposed on the rotation axis X1 side.

  A d-axis Xd and a q-axis Xq are set by the permanent magnet 10. The d-axis Xd is the direction of magnetic flux generated by the magnetic poles of the permanent magnet 10 and is the central axis of the permanent magnet 10. The q axis Xq is an axis that is electrically and magnetically orthogonal to the d axis Xd, and is the central axis between the adjacent permanent magnets 10 of different magnetic poles. When one permanent magnet 10 is viewed, the q axis Xq is set on one side and the other side in the circumferential direction of the permanent magnet 10.

  Hereinafter, the configuration around the permanent magnet 10 and the accommodation hole 20 located in the 12 o'clock direction region of the timepiece of the rotor core 2 shown in FIG. 1 will be described in detail with reference to an enlarged view of FIGS. In the permanent magnet 10 located in the region, the q axis Xq located on one side in the circumferential direction is defined as Xq1, and the q axis Xq located on the other circumferential direction is defined as Xq2. Since the area and the other area are point-symmetrical with the rotation axis X1 as the center of symmetry when viewed from the direction of the rotation axis X1, the description of the other areas is omitted.

  As shown in FIG. 2, the accommodation hole 20 has a first flux barrier 21 and a second flux barrier 22. The first flux barrier 21 and the second flux barrier 22 are examples of the “flux barrier” of the present invention.

  The first flux barrier 21 is located on the q axis Xq (Xq1) side of the permanent magnet 10. The first flux barrier 21 bulges so that one end surface in the circumferential direction of the accommodation hole 20 is separated from the end surface 11 on the q-axis Xq (Xq1) side of the permanent magnet 10. The first flux barrier 21 is formed by a gap between the end surface 11 of the permanent magnet 10 and suppresses the magnetic flux of the permanent magnet 10 from being short-circuited.

  The second flux barrier 22 is located on the q axis Xq (Xq2) side of the permanent magnet 10. The second flux barrier 22 bulges so that the other end surface in the circumferential direction of the accommodation hole 20 is separated from the end surface 12 on the q-axis Xq (Xq2) side of the permanent magnet 10. The second flux barrier 22 is formed by a gap between the end surface 12 of the permanent magnet 10 and suppresses the magnetic flux of the permanent magnet 10 from being short-circuited.

  The rotor core 2 is formed with a d-axis core portion 2D and a q-axis core portion 2Q. The d-axis core portion 2D is a portion located on the outer side in the radial direction with respect to the permanent magnet 10 in the rotor core 2, in other words, the outer peripheral edge 2E of the rotor core 2 and the end extending in the circumferential direction on the outer side in the radial direction in the accommodation hole 20. It is a part sandwiched between edges. The q-axis core portion 2Q is a portion aligned in the circumferential direction with respect to the d-axis core portion 2D in the rotor core 2. The q-axis core part 2Q located on the q-axis Xq (Xq1) side in the permanent magnet 10 is 2Q1, and the q-axis core part 2Q located on the q-axis Xq (Xq2) side in the permanent magnet 10 is 2Q2.

  Further, the rotor core 2 is formed with one first continuous slit 31 and five first independent slits 41 on the q-axis Xq (Xq1) side of the permanent magnet 10, and six first slits. One bridge 51 is formed.

  The rotor core 2 is provided with one second continuous slit 32 and five second independent slits 42 on the q-axis Xq (Xq2) side of the permanent magnet 10, and six sixth slits. Two bridges 52 are formed.

  The first continuous slit 31, each first independent slit 41 and each first bridge 51, and the second continuous slit 32, each second independent slit 42 and each second bridge 52 are lines having the d axis Xd as the target axis. Symmetrical relationship.

  The first continuous slit 31 and the second continuous slit 32 are examples of the “continuous slit” in the present invention. Each first independent slit 41 and each second independent slit 42 is an example of the “independent slit” in the present invention. Each first bridge 51 and each second bridge 52 are examples of the “bridge” of the present invention.

  The first continuous slit 31 is continuous with the portion located on the outer side in the radial direction in the first flux barrier 21 and extends toward the side opposite to the permanent magnet 10 in the circumferential direction. The first continuous slit 31 is a groove extending in a substantially arc shape around the rotation axis X1. The first continuous slit 31 does not protrude outward in the radial direction from the first flux barrier 21. The radial width W31 of the first continuous slit 31 is smaller than the radial width W21 of the first flux barrier 21.

  The second continuous slit 32 is continuous with a portion located on the outer side in the radial direction in the second flux barrier 22 and extends toward the opposite side to the permanent magnet 10 in the circumferential direction. The second continuous slit 32 is a groove extending in a substantially arc shape around the rotation axis X1. The second continuous slit 32 does not protrude outward in the radial direction from the second flux barrier 22. The radial width W32 of the second continuous slit 32 is smaller than the radial width W22 of the second flux barrier 22.

  Each first independent slit 41 extends in the circumferential direction at a position spaced radially outward from the first continuous slit 31. Each of the first independent slits 41 is a groove extending in a substantially arc shape around the rotation axis X1. Each first independent slit 41 has a substantially equal circumferential length L41. The circumferential length L41 of each first independent slit 41 is also substantially equal to the circumferential length L31 of the first continuous slit 31. Furthermore, the radial width W31 of the first continuous slit 31 and the radial width W41 of each first independent slit 41 are substantially equal. Each first independent slit 41 faces the first continuous slit 31 in the radial direction. The first continuous slit 31 and each first independent slit 41 are not displaced in the circumferential direction.

  The radial interval W1A between the first continuous slit 31 and the first independent slit 41 located on the innermost side in the radial direction, and the first independent slit 41 located on the outermost side in the radial direction and the outer peripheral edge 2E of the rotor core 2 The interval W1B in the radial direction and the interval W1C between the first independent slits 41 are substantially equal.

  Each of the second independent slits 42 extends in the circumferential direction at a position away from the second continuous slit 32 in the radial direction. Each of the second independent slits 42 is a groove extending in a substantially arc shape with the rotation axis X1 as the center. Each second independent slit 42 has substantially the same length L42 in the circumferential direction. The circumferential length L42 of each second independent slit 42 is also substantially equal to the circumferential length L32 of the second continuous slit 32. Furthermore, the radial width W32 of the second continuous slit 32 and the radial width W42 of each second independent slit 42 are substantially equal. Each second independent slit 42 faces the second continuous slit 32 in the radial direction. The second continuous slit 32 and each second independent slit 42 are not displaced in the circumferential direction.

  The radial interval W2A between the second continuous slit 32 and the second inner independent slit 42 positioned radially inward, and the outer peripheral edge 2E of the rotor core 2 and the second independent slit 42 positioned outermost in the radial direction The interval W2B in the radial direction and the interval W2C between the second independent slits 42 are substantially equal.

  Each first bridge 51 includes an outer peripheral edge between the first continuous slit 31 and the first independent slit 41 located on the innermost side in the radial direction, and the first independent slit 41 located on the outermost side in the radial direction and the rotor core 2. 2E and between the first independent slits 41. Each first bridge 51 is a beam extending in a substantially arc shape around the rotation axis X1. Each first bridge 51 connects and supports the d-axis core portion 2D and the q-axis core portion 2Q (2Q1).

  Since the sizes and relative positional relationships of the first continuous slits 31 and the first independent slits 41 are set as described above, the first bridges 51 have substantially the same length in the circumferential direction and the radial direction. The widths are almost equal.

  Each of the second bridges 52 is formed between the second continuous slit 32 and the second independent slit 42 located on the innermost side in the radial direction and between the second independent slit 42 located on the outermost side in the radial direction and the outer peripheral edge of the rotor core 2. 2E and between the second independent slits 42. Each second bridge 52 is a beam extending in a substantially arc shape with the rotation axis X1 as the center. Each second bridge 52 connects and supports the d-axis core portion 2D and the q-axis core portion 2Q (2Q2).

  Since the size and relative positional relationship of the second continuous slit 32 and each second independent slit 42 are set as described above, each second bridge 52 has a substantially equal circumferential length and a radial direction. The widths are almost equal.

  A circumferential end 31P of the first continuous slit 31, a circumferential end 32P of the second continuous slit 32, circumferential ends 41P and 41Q of the first independent slits 41, and the second independent slits. The end portions 42P and 42Q in the circumferential direction 42 are rounded. That is, the inner peripheral surface of the circumferential end 32P of the second continuous slit 32 and the inner peripheral surface of the circumferential end 32P of the second continuous slit 32 have an R shape or an arc shape. Further, the inner peripheral surfaces of the circumferential end portions 41P and 41Q in each first independent slit 41 and the inner peripheral surfaces of the circumferential end portions 42P and 42Q in each second independent slit 42 are R-shaped or circular arcs. It has a shape.

  In the rotating electric machine configured as described above, during operation, a current is supplied to the coil 7 of the stator 9, a rotating magnetic field is generated in the stator 9, and the rotating magnetic field acts on the rotor 1. Then, the rotor 1 rotates in synchronization with the rotating magnetic field by the magnetic attractive force and the repulsive force between the rotating magnetic field and the permanent magnet 10.

<Effect>
In the rotor 1 according to the first embodiment, centrifugal force acts on the rotor core 2 when the rotating electrical machine operates, and stress is generated in the rotor core 2. This stress acts to expand the rotor core 2 and stretch the outer peripheral edge 2E. Therefore, the rotor core 2 is deformed from the state shown in FIG. 2 (the state shown by the two-dot chain line in FIG. 3) to the state shown by the solid line in FIG. Note that the state shown by the solid line in FIG. 3 is illustrated with emphasis, and the actual amount of deformation is slight. Further, the amount of deformation increases or decreases according to the change in the number of rotations of the rotor.

  In the rotor 1, the stress generated in the periphery of the accommodation hole 20 and the first flux barrier 21 in the rotor core 2 is a single first width that is smaller in the radial width W <b> 31 than the radial width W <b> 21 of the first flux barrier 21. Dispersed from the vicinity of the permanent magnet 10 by the one continuous slit 31, the five first independent slits 41, and the six first bridges 51. That is, in this rotor 1, six narrow beam-shaped first bridges 51 are arranged in parallel around the first flux barrier 21, and each of the first bridges 51 includes the d-axis core portion 2D and the q-axis core portion. 2Q (2Q1) is connected and supported. In particular, since the size and relative positional relationship of the first continuous slit 31 and each first independent slit 41 are set as described above, each first bridge 51 has a circumferential length and a radial width. Evenly aligned. For this reason, each first bridge 51 is similarly deformed as indicated by a solid line in FIG. 3, whereby the stress acting on the periphery of the accommodation hole 20 and the first flux barrier 21 can be distributed to each first bridge 51.

  In the rotor 1, the stress generated around the accommodation hole 20 and the second flux barrier 22 in the rotor core 2 is one in which the radial width W32 is smaller than the radial width W22 of the second flux barrier 22. The second continuous slits 32, the five second independent slits 42, and the six second bridges 52 are dispersed from the vicinity of the permanent magnet 10. That is, in this rotor 1, six narrow beam-like second bridges 52 are arranged in parallel around the second flux barrier 22, and each of the second bridges 52 includes the d-axis core portion 2D and the q-axis core portion. 2Q (2Q2) is connected and supported. In particular, since the size and relative positional relationship of the second continuous slit 32 and each second independent slit 42 are set as described above, each second bridge 52 has a circumferential length and a radial width. Evenly aligned. For this reason, as each 2nd bridge | bridging 52 deform | transforms similarly as shown as a continuous line in FIG. 3, the stress which acts on the periphery of the accommodation hole 20 and the 2nd flux barrier 22 can be disperse | distributed to each 2nd bridge | bridging 52. FIG.

  As a result, in the rotor 1, the maximum stress acting on the periphery of the accommodation hole 20 and the first and second flux barriers 21 and 22 in the rotor core 2 can be reliably reduced. Thereby, in this rotor 1, even if the mass of the permanent magnet 10 is increased to increase the magnet torque and the maximum rotational speed of the rotor 1 is set high, the maximum stress generated in the rotor core 2 is within the allowable range. It becomes difficult to exceed. For this reason, it becomes easy to achieve both an increase in magnet torque and an increase in maximum rotational speed.

  And in this rotor 1, since there is no connection part which concerns on the conventional rotor mentioned above, there is no leakage magnetic flux which passes through such a connection part, and d-axis inductance Ld is reduced. In the rotor 1, the first and second continuous slits 31 and 32, the first and second independent slits 41 and 42, and the first and second bridges 51 and 52 restrict the core width between the magnetic poles of the permanent magnet 10. Since the aperture length can be increased while maintaining the aperture width, the leakage magnetic flux passing through the first and second bridges 51 and 52 can also be reduced. As a result, the rotor 1 can efficiently generate magnet torque and can suppress a decrease in reluctance torque.

  Therefore, in the rotor 1 of Example 1, the performance improvement of a rotary electric machine is realizable.

  Moreover, in this rotor 1, as shown in FIG. 2, the radial widths W31 and W32 of the first and second continuous slits 31 and 32 are the radial widths W21 and W22 of the first and second flux barriers 21 and 22, respectively. Smaller than. Thereby, the 1st, 2nd continuous slits 31 and 32 are hard to influence the effect | action of the 1st, 2nd flux barriers 21 and 22 which suppress that the magnetic flux of a permanent magnet short-circuits.

  Further, in the rotor 1, the first and second continuous slits 31 and 32 do not protrude outward in the radial direction from the first and second flux barriers 21 and 22. Accordingly, a plurality of first and second independent slits 41 and 42 can be arranged between the first and second continuous slits 31 and 32 and the outer circumferential edge 2E of the rotor core 2 without increasing the radial distance therebetween. It is possible.

  Further, in the rotor 1, circumferential end portions 31P and 32P in the first and second continuous slits 31 and 32 and circumferential end portions 41P, 41Q and 42P in the first and second independent slits 41 and 42, respectively. Since 42Q is rounded, the stress concentration at the ends of the first and second bridges 51 and 52 can be alleviated.

  The number, shape, size, or relative positional relationship of the first and second continuous slits 31 and 32, the first and second independent slits 41 and 42, and the first and second bridges 51 and 52 are, for example, the following embodiments. It can be changed as 2-7. In addition, a plurality of configurations in Examples 1 to 7 can be combined as appropriate.

(Example 2)
As shown in FIG. 4, in the rotor of Example 2, the 1st continuous slit 31 and each 1st independent slit 41 have shifted | deviated in the circumferential direction. More specifically, each first independent slit 41 is shifted to the d-axis Xd side with respect to the first continuous slit 31 as compared with the first embodiment. Moreover, the 2nd continuous slit 32 and each 2nd independent slit 42 are also shifted | deviated in the circumferential direction. More specifically, each second independent slit 42 is shifted to the d-axis Xd side with respect to the second continuous slit 32 as compared with the first embodiment. In the second embodiment, the configuration other than the above-described changes is the same as that of the first embodiment.

Example 3
As shown in FIG. 5, in the rotor of Example 3, the first continuous slit 31 and the first independent slits 41 have different circumferential lengths L41. More specifically, the first continuous slit 31 and each first independent slit 41 are longer toward the outer side in the radial direction. The second continuous slit 32 and each second independent slit 42 also have different circumferential lengths L42. More specifically, the second continuous slit 32 and each of the second independent slits 42 are longer toward the outer side in the radial direction. In the third embodiment, the configuration other than the above-described changes is the same as that of the first embodiment.

Example 4
As shown in FIG. 6, in the rotor of the fourth embodiment, the number of the first and second independent slits 41 and 42 is reduced to three, and the number of the first and second bridges 51 and 52 is reduced to four, respectively. Has been. The first continuous slit 31 and each first independent slit 41 have different radial widths W31 and W41. More specifically, the first continuous slit 31 and each first independent slit 41 are wider toward the outer side in the radial direction. The second continuous slit 32 and each second independent slit 42 also have different radial widths W32 and W42. More specifically, the second continuous slit 32 and each second independent slit 42 are also wider toward the outer side in the radial direction. The configuration of the fourth embodiment is the same as that of the first embodiment except for the changes described above.

(Example 5)
As shown in FIG. 7, in the rotor of the fifth embodiment, the number of the first and second independent slits 41 and 42 is reduced to three, and the number of the first and second bridges 51 and 52 is reduced to four, respectively. Has been. The first bridges 51 have different radial widths W1A, W1B, and W1C. More specifically, each first bridge 51 is wider toward the outer side in the radial direction. Each second bridge 52 also has different radial widths W2A, W2B, and W2C. More specifically, each second bridge 52 is also wider toward the outer side in the radial direction. In the fifth embodiment, the configuration other than the above-described changes is the same as that of the first embodiment.

<Operational effects of Examples 2 to 5>
In the rotors of Examples 2 to 5 having such a configuration, the first and second continuous slits 31 and 32, the first and second independent slits 41 and 42, and the first and second bridges 51 that form the diaphragm described above. , 52 can be appropriately optimized according to the rotor specifications, required performance, and the like. As a result, the aperture width and aperture length can be suitably set, and the leakage magnetic flux passing through the first and second bridges 51 and 52 can be effectively reduced.

(Example 6)
As shown in FIG. 8, in the rotor of the sixth embodiment, the number of first and second independent slits 41 and 42 is reduced to two, and the number of first and second bridges 51 and 52 is reduced to three. Has been. The first and second bridges 51 and 52 are bent in the circumferential direction. More specifically, each first bridge 51 is curved in a substantially S shape such that the d-axis Xd side swells radially inward and the q-axis Xq (Xq1) side swells radially outward. Yes. Each second bridge 52 is curved in a substantially S shape so that the d-axis Xd side swells radially inward and the q-axis Xq (Xq2) side swells radially outward. The first and second bridges 51 and 52 extend outward in the radial direction as they are separated from the permanent magnet 10 in the circumferential direction. The configuration of the sixth embodiment is the same as that of the first embodiment except for the changes described above.

<Effect of Example 6>
In the rotor of the sixth embodiment, centrifugal force acts on the rotor core 2 when the rotating electrical machine is operated, and stress is generated in the rotor core 2. This stress acts to expand the rotor core 2 and stretch the outer peripheral edge 2E. For this reason, the rotor core 2 is deformed from the state shown in FIG. 8 (the state shown by the two-dot chain line in FIG. 9) to the state shown by the solid line in FIG. Note that the state shown by the solid line in FIG. 9 is shown in an emphasized manner, and the actual amount of deformation is slight. Further, the amount of deformation increases or decreases according to the change in the number of rotations of the rotor.

  In this rotor, when centrifugal force acts on the rotor core 2, the portions of the first and second bridges 51 and 52 that are curved in a substantially S shape are deformed so as to be stretched as shown by the solid line in FIG. 9. Accordingly, the tensile stress acting on each of the first and second bridges 51 and 52 can be relaxed.

  Further, when each of the first and second bridges 51 and 52 is separated from the permanent magnet 10 in the circumferential direction and extends toward the outer side in the radial direction, each centrifugal force acts on the rotor core 2. Since the extension amounts of the first and second bridges 51 and 52 are reduced, the tensile stress acting on the first and second bridges 51 and 52 can be further relaxed.

(Example 7)
As shown in FIG. 10, in the rotor of Example 7, the first and second continuous slits 31 and 32 do not protrude beyond the first and second flux barriers 21 and 22 in the radial direction. The widths W31 and W32 of the first and second flux barriers 21 and 22 are substantially equal to the radial widths W21 and W22. The configuration of the seventh embodiment is the same as that of the first embodiment except for the changes described above.

<Effect of Example 7>
In the rotor of the seventh embodiment, the performance improvement of the rotating electrical machine can be realized as in the rotor 1 of the first embodiment. Further, in this rotor, the first and second continuous slits 31 and 32 do not protrude outward in the radial direction from the first and second flux barriers 21 and 22. Accordingly, a plurality of first and second independent slits 41 and 42 can be arranged between the first and second continuous slits 31 and 32 and the outer circumferential edge 2E of the rotor core 2 without increasing the radial distance therebetween. It is possible.

  In the above, the present invention has been described with reference to the first to seventh embodiments. However, the present invention is not limited to the first to seventh embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  The present invention is applicable to a rotating electrical machine.

DESCRIPTION OF SYMBOLS 1 ... Permanent magnet buried type rotor 20 ... Accommodating hole 2 ... Rotor core 10 ... Permanent magnet Xd ... d axis Xq ... q axis 11, 12 ... End surface 21 of the permanent magnet q axis side 21, 22 ... Flux barrier (21 ... 1st Flux barrier, 22 ... second flux barrier)
2D ... d-axis core part 2Q ... q-axis core part 31, 32 ... continuous slit (31 ... first continuous slit, 32 ... second continuous slit)
41, 42 ... independent slit (41 ... first independent slit, 42 ... second independent slit)
W31, W32: radial width of continuous slit (W31: radial width of first continuous slit, W32: radial width of second continuous slit)
W21, W22: radial width of the flux barrier (W21: radial width of the first flux barrier, W22: radial width of the second flux barrier)
2E ... Outer peripheral edge of rotor core 51, 52 ... Bridge (51 ... First bridge, 52 ... Second bridge)
31P, 32P ... circumferential end of the continuous slit (31P ... circumferential end of the first continuous slit, 32P ... circumferential end of the second continuous slit)
41P, 41Q, 42P, 42Q ... end in the circumferential direction of the independent slit (41P, 41Q ... end in the circumferential direction in the first independent slit, 42P, 42Q ... end in the circumferential direction in the second independent slit)
L41, L42 ... length in the circumferential direction of the independent slit (L41 ... length in the circumferential direction of the first independent slit, L42 ... length in the circumferential direction of the second independent slit)
L31, L32 ... the circumferential length of the continuous slit (L31 ... the circumferential length of the first continuous slit, L32 ... the circumferential length of the second continuous slit)
W41, W42 ... radial width of the independent slit (W41 ... radial width of the first independent slit, W42 ... radial width of the second independent slit)

Claims (12)

A rotor core formed with a plurality of accommodation holes arranged in the circumferential direction, and a permanent magnet accommodated and held in each accommodation hole;
In the permanent magnet embedded rotor of the rotating electrical machine in which the d axis and the q axis are set by the permanent magnet,
The accommodation hole is formed by a gap between the permanent magnet and the end surface on the q-axis side, and has a flux barrier that suppresses short-circuiting of the magnetic flux of the permanent magnet,
In the rotor core,
A d-axis core portion located radially outside the permanent magnet;
A q-axis core portion arranged in the circumferential direction with respect to the d-axis core portion;
A continuous slit extending continuously from the flux barrier toward the opposite side of the permanent magnet in the circumferential direction, and having a radial width smaller than the flux barrier,
An independent slit extending in the circumferential direction at a position spaced outward in the radial direction with respect to the continuous slit, and facing the continuous slit in the radial direction;
Between the continuous slit and the outer peripheral edge of the rotor core, it is arranged side by side on the inner side and the outer side in the radial direction with respect to the independent slit, and connects and supports the d-axis core part and the q-axis core part. A permanent magnet-embedded rotor for a rotating electrical machine, wherein a plurality of bridges are formed. The flux barrier is composed of a first flux barrier located on one q-axis side of the permanent magnet and a second flux barrier located on the other q-axis side of the permanent magnet,
The continuous slit is continuous with the first flux barrier and extends toward the opposite side of the permanent magnet in the circumferential direction. The continuous slit is continuous with the second flux barrier and the permanent in the circumferential direction. A second continuous slit extending toward the opposite side of the magnet,
The independent slit extends in the circumferential direction at a position spaced outward in the radial direction with respect to the first continuous slit, the first independent slit facing the first continuous slit in the radial direction, and the second A continuous slit extending in the circumferential direction at a position spaced outward in the radial direction, and comprising a second independent slit facing the second continuous slit in the radial direction;
The bridge includes a first bridge arranged between the first continuous slit and the outer peripheral edge, arranged inward and outward in the radial direction with respect to the first independent slit, and the second continuous slit, 2. The permanent magnet embedded rotor of a rotating electrical machine according to claim 1, comprising a second bridge arranged between the outer peripheral edge and the radially inner side and the outer side with respect to the second independent slit.   3. The permanent magnet embedded rotor of a rotating electrical machine according to claim 1, wherein the circumferential end of the continuous slit and the circumferential end of at least one of the independent slits are rounded. 4. A plurality of the independent slits are formed,
Each of the independent slits has a substantially equal length in the circumferential direction,
4. The permanent magnet embedded rotor of a rotating electrical machine according to claim 1, wherein the continuous slit and each independent slit are displaced in the circumferential direction. 5.   4. The permanent magnet embedded rotor of a rotating electrical machine according to claim 1, wherein the continuous slit and the independent slit have different lengths in the circumferential direction. 5.   The permanent magnet embedded type rotor for a rotating electrical machine according to claim 5, wherein the continuous slit and the independent slit have a longer length in the circumferential direction toward the outer side in the radial direction.   The permanent magnet embedded rotor of a rotating electrical machine according to any one of claims 1 to 6, wherein the continuous slit and the independent slit have different radial widths.   The permanent magnet embedded type rotor for a rotating electrical machine according to claim 1, wherein each of the bridges has a different width in the radial direction.   The permanent magnet embedded type rotor for a rotating electrical machine according to claim 1, wherein each of the bridges is bent in the circumferential direction.   10. The permanent magnet-embedded rotor for a rotating electrical machine according to claim 1, wherein each of the bridges extends toward the outside in the radial direction as the bridge is separated from the permanent magnet in the circumferential direction. .   4. The permanent magnet-embedded rotor according to claim 1, wherein each of the bridges has a substantially equal length in the circumferential direction and a substantially equal width in the radial direction. 5. A rotor core formed with a plurality of accommodation holes arranged in the circumferential direction, and a permanent magnet accommodated and held in each accommodation hole;
In the permanent magnet embedded rotor of the rotating electrical machine in which the d axis and the q axis are set by the permanent magnet,
The accommodation hole is formed by a gap between the permanent magnet and the end surface on the q-axis side, and has a flux barrier that suppresses short-circuiting of the magnetic flux of the permanent magnet,
In the rotor core,
A d-axis core portion located radially outside the permanent magnet;
A q-axis core portion arranged in the circumferential direction with respect to the d-axis core portion;
A continuous slit extending continuously from the flux barrier toward the opposite side of the permanent magnet in the circumferential direction and not protruding outward in the radial direction from the flux barrier;
An independent slit extending in the circumferential direction at a position spaced outward in the radial direction with respect to the continuous slit, and facing the continuous slit in the radial direction;
Between the continuous slit and the outer peripheral edge of the rotor core, it is arranged side by side on the inner side and the outer side in the radial direction with respect to the independent slit, and connects and supports the d-axis core part and the q-axis core part. A permanent magnet-embedded rotor for a rotating electrical machine, wherein a plurality of bridges are formed.

Images