JP5067365B2 - motor - Google Patents

Description

  The present invention relates to a permanent magnet embedded brushless motor equipped with a twin rotor, and more particularly to a configuration of a rotor.

  FIG. 9 shows a toroidal brushless motor having a conventional twin rotor, which includes a stator 110, an inner rotor 120, and an outer rotor 130.

  The stator 110 includes a stator core 111 and a coil 115. The stator core 111 includes a stator yoke 114, an outer tooth 112 and an inner tooth 113 provided on the stator yoke 114, an outer slot 116 between the outer teeth 112, and an inner slot 117 between the inner teeth 113. Are each configured.

  The stator yoke 114 is provided with a plurality of toroidal three-phase coils 115. The coil 115 is wound around the stator yoke 114 by a concentrated winding method, and is accommodated in the outer slot 116 and the inner slot 117, and is star-connected or delta-connected.

  The inner rotor 120 is directly connected to the rotary shaft 140 and is rotatably held inside the stator 110. The inner rotor 120 further includes an inner rotor yoke 121 and a permanent magnet 122. The inner rotor yoke 121 is provided with a plurality of permanent magnet insertion holes 124, into which the permanent magnets 122 are inserted and bonded and fixed.

  Similarly, the outer rotor 130 is directly connected to the rotating shaft 140 and is rotatably held outside the stator 110. The outer rotor 130 further includes a rotor yoke 131 and a permanent magnet 132. The outer rotor yoke 131 is provided with a plurality of permanent magnet insertion holes 134, into which the permanent magnets 132 are inserted and fixed.

  The inner rotor 120 and the outer rotor 130 are rotated by a magnetic field generated by a current flowing through the coil 115. The configuration of such a toroidal brushless motor is disclosed in Patent Document 1, for example.

According to this conventional motor, the output torque can be increased by adopting a twin rotor configuration for the rotor, but there is a problem that the cogging torque increases and the vibration and noise increase.
Japanese Patent Application Publication No. 2001-37133

  The motor of the present invention has the following configuration. An annular stator yoke, a plurality of inner teeth projecting radially inward from the stator yoke, and a plurality of outer teeth projecting radially outward from the stator yoke in the same number as the inner teeth. In addition, the stator core includes an inner slot configured between the inner teeth and an outer slot configured between the outer teeth. In addition, the stator includes a plurality of coils wound around a stator yoke between the inner slot and the outer slot and connected in a three-phase star or delta shape.

  An inner rotor that faces the inner teeth via a gap and an outer rotor that faces the outer teeth via a gap are included, and the inner rotor and the outer rotor are connected to the same rotation shaft.

  The inner rotor has an inner rotor yoke having a plurality of inner permanent magnet insertion holes and a plurality of inner permanent magnets embedded in the inner permanent magnet insertion holes, and the outer rotor has an outer surface having a plurality of outer permanent magnet insertion holes. The rotor yoke and a plurality of outer permanent magnets embedded in the outer permanent magnet insertion holes are provided.

  Both the rotation center of the rotation shaft and the magnetic pole center line connecting the magnetic pole center of the inner rotor and the magnetic pole center of the outer rotor, and the magnetic flux boundary line connecting the rotation center of the rotation shaft and the magnetic flux boundary of the inner rotor and the magnetic flux boundary of the outer rotor, It is a straight line.

  A point where the magnetic pole center line intersects the outer shape of the inner rotor yoke is an end point X1, and a point where the magnetic pole center line intersects the inner shape of the outer rotor yoke is an end point X2. A point where the magnetic flux boundary line intersects the outer shape of the inner rotor yoke is an end point Z1, and a point where the magnetic flux boundary line intersects the inner shape of the outer rotor yoke is an end point Z2. The end point A1 is a point having a predetermined angle θ1 in the direction of the magnetic pole boundary line from the magnetic pole center line and passing through the rotation center, and the predetermined angle θ2 in the direction of the magnetic pole boundary line from the magnetic pole center line. The point where the straight line passing through the center of rotation intersects the inner shape of the outer rotor yoke is defined as an end point A2.

Here, the cross-sectional shape of the inner rotor yoke is connected between the end point A1 and the end point Z1 by at least two continuous straight lines, and the cross-sectional shape of the outer rotor yoke is at least two continuous points between the end point A2 and the end point Z2. When the shortest distance between the end of the inner permanent magnet insertion hole and the outer shape of the inner rotor yoke is L1, and the thickness of one of the high-permeability thin iron plates constituting the inner rotor yoke is d / 2 <L1 <2d or the shortest distance between the end of the outer permanent magnet insertion hole and the inner shape of the outer rotor yoke is L2, and the thickness of one of the high-permeability thin iron plates constituting the outer rotor yoke is when the e, whether it is e / 2 <L2 <2e, the Ru der least one.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a motor according to an embodiment of the present invention. The motor of the present embodiment includes a stator 10, an inner rotor 20 that faces the inner diameter side of the stator 10, and an outer rotor 30 that faces the outer diameter side.

  The stator core 11 constituting the stator 10 includes a substantially annular stator yoke 14, outer teeth 12 projecting from the stator yoke 14 in the outer peripheral direction, and inner teeth projecting from the stator yoke 14 in the same number as the outer teeth 12. 13 and. Outer slots 16 are formed between the outer teeth 12, and inner slots 17 are formed between the inner teeth 13.

  A plurality of coils 15 connected in a three-phase star or delta shape and having a toroidal winding form are wound around the stator yoke 14 between the outer slot 16 and the inner slot 17 in a concentrated winding manner. The coil 15 is accommodated in all slots.

  An outer rotor 30 is disposed facing the outer teeth 12 via a predetermined air gap. Similarly, the inner rotor 20 is disposed through a predetermined air gap so as to face the inner teeth 13.

  The outer rotor 30 has an outer permanent magnet insertion hole 34 in an outer rotor yoke 31 on which electromagnetic steel plates are laminated, and an outer permanent magnet 32 is housed therein to form an outer magnetic pole portion. Similarly, the inner rotor 20 has an inner permanent magnet insertion hole 24 in an inner rotor yoke 21 in which electromagnetic steel plates are laminated, and the inner permanent magnet 22 is housed therein to form an inner magnetic pole portion. In other words, the outer magnetic pole portion is configured by accommodating the outer permanent magnet 32 in each of the plurality of outer permanent magnet insertion holes 34 of the outer rotor yoke 31. Similarly, the inner magnetic pole portion is configured by accommodating the inner permanent magnet 22 in each of the plurality of inner permanent magnet insertion holes 24 of the inner rotor yoke 21.

  Here, when a straight line connecting the center of the inner permanent magnet 22 and the center of the outer permanent magnet 32 is extended, it is configured to pass through the rotation center 41, and this straight line is defined as a magnetic pole center line 27. Further, when the straight line connecting the intermediate point between the inner permanent magnet 22 and the adjacent inner permanent magnet 22 and the intermediate point between the outer permanent magnet 32 and the adjacent outer permanent magnet 32 is extended, the rotation center 41 is passed. This straight line is defined as a magnetic flux boundary line 28. That is, the inner permanent magnet 22 and the outer permanent magnet 32 are arranged in the same phase.

  The outer rotor 30 is coupled to an outer rotor frame (not shown) by means such as press fitting, shrink fitting, or adhesion. Similarly, the inner rotor 20 is coupled to an inner rotor frame (not shown) by means such as press fitting, shrink fitting, or adhesion. The inner rotor frame and the outer rotor frame are configured to be detachable. However, normally, the inner rotor frame and the outer rotor frame are connected to the rotating shaft 40 and rotate integrally by applying a predetermined current to the coil 15.

  Here, as described above, the outer rotor 30 and the inner rotor 20 have permanent magnet insertion holes 34 and 24, respectively, in which the outer permanent magnet 32 and the inner permanent magnet 22 are housed. The number of outer permanent magnet insertion holes 34 and the number of inner permanent magnet insertion holes 24 is the same, both of which have a trapezoidal cross section, and the rotor yoke between adjacent permanent magnet insertion holes is set to have a uniform thickness. . The circumferential length of the outer permanent magnet insertion hole 34 is longer than that of the inner permanent magnet insertion hole 24, and the radial length is the same. The outer permanent magnet 32 is inserted into the outer permanent magnet insertion hole 34, the inner permanent magnet 22 is inserted into the inner permanent magnet insertion hole 24, and both are bonded and fixed. Each of the permanent magnets has a rectangular cross section, and the outer circumferential magnet 32 is longer than the inner permanent magnet 22 in the circumferential direction, and the radial length is the same. The inner permanent magnet insertion hole 24 and the outer permanent magnet insertion hole 34 are both configured to have gaps at both ends in the circumferential direction when the permanent magnet is inserted. This is to prevent a short circuit of magnetic flux between adjacent permanent magnets.

  As for the magnetic pole property of the permanent magnet, the N and S poles are alternately arranged in both the outer and inner permanent magnets 32 and 22. Torque is generated in the outer rotor 30 by the current flowing in the coil of the outer slot 16 and torque is generated in the inner rotor 20 by the current flowing in the coil of the inner slot 17, so that a large torque can be obtained with the same current. Furthermore, since a reluctance torque is added by adopting a permanent magnet embedded structure, a small, large torque, and high efficiency motor can be realized. Moreover, since the coil 15 has a concentrated winding structure, the winding space factor in each slot can be improved and the coil end portion can be made small, which can contribute to further improvement in efficiency.

  Further, in the present embodiment, the outer permanent magnet 32 and the inner permanent magnet 22 are both formed into a rectangular shape, so that the machining cost of the magnet is greatly reduced, unlike a generally adopted arc-shaped magnet. be able to. Thereby, in addition to small size, large torque, and high efficiency, cost reduction can be realized.

  Next, FIG. 2 is a partial cross-sectional view showing a main part of the inner rotor 20 of the present embodiment. In FIG. 2, a point where a magnetic pole center line 27 connecting the center of the inner permanent magnet 22 with the rotation center 41 intersects the outer shape of the inner rotor yoke 21 is defined as an end point X1. Further, the end point Z1 is a point where the magnetic flux boundary line 28 connecting the intermediate point between the inner permanent magnet 22 and the adjacent inner permanent magnet 22 from the rotation center 41 intersects the outer shape of the inner rotor yoke 21. The electrical angle from the magnetic pole center line 27 to the magnetic flux boundary line 28 is 90 °.

  This end point Z1 is defined as follows. The shortest distance between the end of the inner permanent magnet insertion hole 24 and the outer straight line B1-Z1 (described later) of the inner rotor yoke 21 is L1, and the thickness of one high permeability thin iron plate constituting the inner rotor yoke 21 is d. Where d / 2 <L1 <2d. If the shortest distance L1 from the outer shape is d / 2 or less, pressing becomes difficult, and further, the strength of the inner rotor yoke 21 is significantly reduced. Further, when the shortest distance L1 from the outer shape is set to 2d or more, the output torque is greatly reduced because the magnetic flux interlinking with the coil is reduced. This is because the amount of leakage magnetic flux between adjacent permanent magnets in the inner rotor yoke 21 increases as L1 increases. For this reason, the increased magnetic flux does not interlink with the stator. From the above, the above range is optimal for the value of the shortest distance L1 from the outer shape. Further, the end of the inner permanent magnet insertion hole 24 for determining the shortest distance L1 from the outer shape is the portion closest to the outer shape of the inner permanent magnet insertion hole 24 as shown in the figure.

  Next, a point that has a predetermined angle θ1 in the direction of the magnetic flux boundary line 28 from the magnetic pole center line 27 and that passes through the rotation center 41 and the outer shape of the inner rotor yoke 21 is defined as an end point A1, and between the end point X1 and the end point A1. And an arc (first arc) centered on the rotation center 41. The predetermined angle θ1 is in the range of 15 ° <θ1 <75 ° in electrical angle. More preferably, the range is 15 ° <θ1 <60 °.

  Next, the end point A1 and the end point Z1 are connected by two continuous straight lines. That is, they are connected by a straight line A1-B1 and a straight line B1-Z1. The end point B1 has an angle θ1b with the magnetic pole center line 27. As described above, the outer shape of the inner rotor yoke 21 is connected by an arc from the end point X1 at which the magnetic pole center line 27 intersects to the end point A1, and is connected by two straight lines from the end point A1 to the end point B1 and the end point Z1. . Two straight lines continuing from the end point A1 to the end point B1 and the end point Z1 are located inside a circle obtained by extending the arc from the end point X1 to the end point A1 with the same curvature.

  At this time, the shape of the end point B1 is a convex shape (<180 °). Thereby, the distance Lb1 to the end point B1 and the distance Lz1 to the end point Z1 are Lb1 <Lz1 as a circle (indicated by a broken line) obtained by extending the arc X1-A1 with the same curvature. That is, the gap from the inner peripheral surface of the inner tooth 13 of the stator core 11 increases as the distance from the magnetic pole center line 27 increases.

  Next, FIG. 3 is a partial cross-sectional view showing the main part of the outer rotor 30 of the present embodiment. In FIG. 3, a point where a magnetic pole center line 27 connecting the center of the outer permanent magnet 32 with the rotation center 41 intersects with the inner shape of the outer rotor yoke 31 is defined as an end point X2. Further, an end point Z <b> 2 is a point where a magnetic flux boundary line 28 connecting an intermediate point between the outer permanent magnet 32 and the adjacent outer permanent magnet 32 from the rotation center 41 intersects the inner shape of the outer rotor yoke 31. The electrical angle from the magnetic pole center line 27 to the magnetic flux boundary line 28 is 90 °.

  This end point Z2 is defined as follows. The shortest distance between the end of the outer permanent magnet insertion hole 34 and an inner straight line B2-Z2 (described later) of the outer rotor yoke 31 is L2, and the thickness of one of the high-permeability thin iron plates constituting the outer rotor yoke 31 is When e is set, e / 2 <L2 <2e. If the shortest distance L2 from the inner shape is set to e / 2 or less, pressing becomes difficult, and the strength of the outer rotor yoke 21 is significantly reduced. When the shortest distance L2 from the inner shape is set to 2e or more, the output torque is greatly reduced because the magnetic flux linked to the coil is reduced. This is because the amount of leakage magnetic flux between adjacent permanent magnets in the outer rotor yoke 31 increases as L2 increases. For this reason, the increased magnetic flux does not interlink with the stator. From the above, the above range is optimal for the value of the shortest distance L2 from the inner shape. Further, the end portion of the permanent magnet insertion hole 34 for determining the shortest distance L2 from the inner shape is the portion closest to the inner shape of the outer permanent magnet insertion hole 34 as shown in the figure.

  Next, a point that has a predetermined angle θ2 in the direction of the magnetic flux boundary line 28 from the magnetic pole center line 27 and passes through the rotation center 41 and the inner shape of the outer rotor yoke 31 is defined as an end point A2, and between the end point X2 and the end point A2 Are connected by an arc (second arc) centered on the rotation center 41. The predetermined angle θ2 is in the range of 15 ° <θ2 <75 ° in electrical angle. More preferably, the range is 15 ° <θ2 <60 °.

  Next, the end point A2 and the end point Z2 are connected by two continuous straight lines. That is, they are connected by a straight line A2-B2 and a straight line B2-Z2. The end point B2 has an angle θ2b with the magnetic pole center line 27. As described above, the inner shape of the outer rotor yoke 31 is connected by an arc from the end point X2 where the magnetic pole center line 27 intersects to the end point A2, and is connected by two straight lines from the end point A2 to the end point B2 and the end point Z2. Become. Two straight lines continuous from the end point A2 to the end point B2 and the end point Z2 are located outside a circle obtained by extending the arc from the end point X2 to the end point A2 with the same curvature.

  At this time, the shape of the end point B2 is a convex shape (<180 °). Thereby, the distance Lb2 to the circle (shown by a broken line) obtained by extending the above-mentioned arc X2-A2 with the same curvature and the end point B2 and the distance Lz2 to the end point Z2 satisfy Lb2 <Lz2. That is, the gap from the outer peripheral surface of the outer tooth 12 of the stator core 11 increases as the distance from the magnetic pole center line 27 increases.

  Next, FIG. 4 shows the relationship between the angle θ1 (electrical angle) from the end point X1 to the end point A1 and the cogging torque in the inner rotor 20, and the angle θ2 (electrical angle) from the end point X2 to the end point A2 in the outer rotor 30 and the cogging. It is a graph which shows the relationship of a torque. A broken line indicates a case where only the inner rotor 20 is present, and a solid line indicates a case where only the outer rotor 30 is present.

  FIG. 5 is a graph showing the relationship between the slot open angle α1 (electrical angle) of the inner rotor 20 and the cogging torque, and the relationship between the slot open angle α2 (electrical angle) of the outer rotor 30 and the cogging torque. A broken line indicates a case where only the inner rotor 20 is present, and a solid line indicates a case where only the outer rotor 30 is present. The slot open is the distance between adjacent teeth in the maximum width portion of the teeth, and the angles α1 and α2 are as shown in FIG.

  Next, FIG. 6 shows the relationship between the slot open angles α1 and α2 and the phase of the cogging torque. It can be confirmed that the cogging torque phase is reversed at the electrical angle of 10 ° and 15 ° for both the slot open angle α1 of the inner rotor 20 and the slot open angle α2 of the outer rotor 30.

  By adjusting the value of the cogging torque associated with the change in the rotor shape shown in FIG. 4 and the change in the slot opening shown in FIG. 5, the phases of the inner cogging torque and the outer cogging torque are reversed, and the inner and outer cogging torque By making the values the same, the cogging torque can be greatly reduced. FIG. 7 shows a cogging torque waveform at this time. The thin broken line indicates the relationship between the slot opening angle α1 of the inner rotor 20 and the cogging torque when only the inner rotor 20 is present, and the thin solid line indicates the slot opening of the outer rotor 30 when only the outer rotor 30 is present. The relationship between the angle α2 and the cogging torque is shown. The thick solid line indicates the cogging torque of the entire motor by combining the cogging torques of the inner rotor 20 and the outer rotor 30. By applying the present invention, the effect of significantly reducing the cogging torque of the entire motor can be confirmed.

  Next, the inner magnet insertion hole 24 and the outer magnet insertion hole 34 have been described as trapezoidal shapes, but are not limited thereto. 8A and 8B show an example different from the trapezoidal shape. In FIG. 8A, the magnet insertion hole 45a (both the inner magnet insertion hole and the outer magnet insertion hole) have protrusions 47a at both ends in the circumferential direction, and the permanent magnet 46a is inserted therein. In FIG. 8B, the magnet insertion hole 45b (both the inner magnet insertion hole and the outer magnet insertion hole) includes protrusions 47b at both ends in the circumferential direction and protrusions 48b at the inner peripheral side of both ends in the circumferential direction. Has been inserted. This shape facilitates positioning of the permanent magnets 46a, 46b, and the protrusions 47a, 47b, 48b function as an adhesive reservoir, and at the same time, prevent a magnetic flux short circuit with the adjacent permanent magnet. In addition, the protrusion part 48b in FIG. 8B can also be provided in the outer peripheral side of the circumferential direction both ends.

  In the present embodiment, the inner rotor 20 has a stack thickness (length in the axial direction) and the outer rotor 30 has a stack thickness (length in the axial direction) that is basically the same. Good. For example, in order to reduce the cogging torque of the entire motor by synthesizing the cogging torque of the inner rotor 20 and the outer rotor 30, for example, the inner rotor 20 may have a larger thickness than the outer rotor 30. It is.

  In the present embodiment, the inner rotor 20 is formed by connecting the end point A1 and the end point Z1 with two continuous straight lines, and includes the straight line A1-B1 and the straight line B1-Z1. Is not limited to two continuous straight lines and may be increased. For example, an end point C1 may be further provided between the end point B1 and the end point Z1, and the straight line A1-B1, the straight line B1-C1, and the straight line C1-Z1 may be connected by three continuous straight lines. Furthermore, the structure which increases the number of straight lines with four and five is also possible.

  Similarly, the outer rotor 30 connects the end point A2 and the end point Z2 with two continuous straight lines, and is constituted by a straight line A2-B2 and a straight line B2-Z2. You may increase more without being limited to. For example, an end point C2 may be further provided between the end point B2 and the end point Z2, and the straight line A2-B2, the straight line B2-C2, and the straight line C2-Z2 may be connected by three continuous straight lines. Furthermore, the structure which increases the number of straight lines with four and five is also possible.

  In the present embodiment, the inner rotor 20 and the outer rotor 30 are described as having the same number of straight lines, but the number is not limited to the same number. For example, the number of straight lines in the inner and outer rotors may be different, for example, the inner rotor 20 may have two straight lines and the outer rotor 30 may have three or four straight lines.

  In the motor of the present invention, the stator 10 can be resin-molded to improve the rigidity of the stator and reduce vibration and noise.

  In the present embodiment, it has been described that the inner rotor frame and the outer rotor frame are connected to the rotating shaft 40. However, the inner rotor 20 and the outer rotor 30 are integrally molded with resin without using these rotor frames. Thus, a structure in which both rotors are connected may be employed.

  In the present embodiment, it has been described that the inner magnet 22 is fixed to the inner magnet insertion hole 24 and the outer magnet 32 is fixed to the outer magnet insertion hole 34. However, an adhesive may not be used. That is, the inner rotor yoke 21, the inner magnet 22, the outer rotor yoke 31, and the outer magnet 32 may be integrally resin-molded, and the inner rotor 20 and the outer rotor 30 may be fixed to each other. Thereby, an adhesion process can be omitted and man-hours can be reduced.

  As described above, the motor according to the present embodiment provides a motor that reduces cogging torque and torque ripple without reducing output torque, reduces harmonic content of induced voltage, and suppresses vibration and noise. be able to.

  INDUSTRIAL APPLICABILITY The present invention is useful for motors that are small in size and limited in space, and that require high output, high efficiency, low vibration / low noise, and low cost, such as home appliances and electrical components.

Sectional drawing of the motor in embodiment of this invention The fragmentary sectional view which shows the inner side rotor of the motor in embodiment of this invention The fragmentary sectional view which shows the outer side rotor of the motor in embodiment of this invention The graph which shows the relationship between the circular arc angles (theta) 1 and (theta) 2 of a motor, and cogging torque in embodiment of this invention The graph which shows the relationship between the motor slot open angle (alpha) 1 and (alpha) 2 and cogging torque in embodiment of this invention. The graph which shows the relationship between the slot open angles (alpha) 1 and (alpha) 2 of a motor and the phase of a cogging torque in embodiment of this invention The graph which shows the relationship between the motor slot open angle (alpha) 1 and (alpha) 2 and cogging torque in embodiment of this invention. Sectional drawing which shows the other form of the permanent magnet insertion hole of the motor in embodiment of this invention Sectional drawing which shows the other form of the permanent magnet insertion hole of the motor in embodiment of this invention Cross section of conventional motor

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stator 11 Stator core 12 Outer teeth 13 Inner teeth 14 Stator yoke 15 Coil 16 Outer slot 17 Inner slot 20 Inner rotor 21 Inner rotor yoke 22 Inner permanent magnet 24 Inner permanent magnet insertion hole 27 Magnetic pole center line 28 Magnetic flux boundary line 30 Outer rotor 31 Outer Rotor yoke 32 Outer permanent magnet 34 Outer permanent magnet insertion hole 40 Rotating shaft 41 Rotation center X1 End point where magnetic pole center line intersects outer rotor yoke outline X2 End point where magnetic pole center line intersects inner shape of outer rotor yoke Z1 Magnetic flux boundary line is inside End point intersecting the outer shape of the rotor yoke Z2 End point where the magnetic flux boundary line intersects the inner shape of the outer rotor yoke A1 A straight line passing through the center of rotation intersects the outer shape of the inner rotor yoke at a predetermined angle θ1 in the direction of the magnetic flux boundary line from the magnetic pole center line. Endpoint A 2 End point where a straight line passing through the center of rotation intersects the inner shape of the outer rotor yoke with a predetermined angle θ2 from the magnetic pole center line in the direction of the magnetic flux boundary line B1 With a predetermined angle θ1b in the direction of the magnetic flux boundary line from the magnetic pole center line End point where the straight line passing through the outer rotor yoke outline B1 A predetermined angle θ2b in the direction of the magnetic flux boundary line from the magnetic pole center line and the end point where the straight line passing through the center of rotation intersects the inner shape of the outer rotor yoke α1 Slot opening angle α2 of the inner rotor Slot opening angle of outer rotor L1 Shortest distance between end of inner permanent magnet insertion hole and outer shape of inner rotor yoke L2 Shortest distance between end of outer permanent magnet insertion hole and inner shape of outer rotor yoke d High permeability of inner rotor yoke The thickness of one iron plate e The thickness of one high permeability iron plate of the outer rotor yoke

Claims (10)

An annular stator yoke, a plurality of inner teeth projecting radially inward from the stator yoke, a plurality of outer teeth projecting radially outward from the stator yoke in the same number as the inner teeth, and the inner side An inner slot configured between the teeth;
A stator core having an outer slot formed between the outer teeth, and a plurality of coils wound around the stator yoke between the inner slot and the outer slot and connected in a three-phase star or delta shape. A stator with
Including an inner rotor facing the inner teeth via a gap and an outer rotor facing the outer teeth via a gap, the inner rotor and the outer rotor being connected to the same rotating shaft,
The inner rotor has an inner rotor yoke having a plurality of inner permanent magnet insertion holes, and a plurality of inner permanent magnets embedded in the inner permanent magnet insertion holes,
The outer rotor has an outer rotor yoke having a plurality of outer permanent magnet insertion holes, and a plurality of outer permanent magnets embedded in the outer permanent magnet insertion holes,
A magnetic pole center line connecting the rotation center of the rotating shaft, the magnetic pole center of the inner rotor, and the magnetic pole center of the outer rotor, and a magnetic flux connecting the rotation center of the rotating shaft, the magnetic flux boundary of the inner rotor, and the magnetic flux boundary of the outer rotor. Both boundaries are straight lines,
A point where the magnetic pole center line intersects the outer shape of the inner rotor yoke is an end point X1, and a point where the magnetic pole center line intersects the inner shape of the outer rotor yoke is an end point X2.
A point where the magnetic flux boundary line intersects the outer shape of the inner rotor yoke is an end point Z1, and a point where the magnetic flux boundary line intersects the inner shape of the outer rotor yoke is an end point Z2.
A point at which a straight line having a predetermined angle θ1 in the direction of the magnetic pole boundary line from the magnetic pole center line and passing through the rotation center intersects the outer shape of the inner rotor yoke is defined as an end point A1.
When the end point A2 is a point having a predetermined angle θ2 in the direction of the magnetic pole boundary line from the magnetic pole center line and passing through the rotation center and intersecting the inner shape of the outer rotor yoke,
The cross-sectional shape of the inner rotor yoke is connected by at least two continuous straight lines between the end point A1 and the end point Z1, and the cross-sectional shape of the outer rotor yoke is at least 2 between the end point A2 and the end point Z2. Connected by two continuous straight lines ,
When the shortest distance between the end portion of the inner permanent magnet insertion hole and the outer shape of the inner rotor yoke is L1, and the thickness of one of the high-permeability thin iron plates constituting the inner rotor yoke is d / 2 < L1 <2d or
Or
When the shortest distance between the end of the outer permanent magnet insertion hole and the inner shape of the outer rotor yoke is L2, and e is the thickness of one of the high-permeability thin iron plates constituting the outer rotor yoke, e / 2 <L2 <either a 2e, at least one der Ru motor. The cross-sectional shape of the inner rotor yoke is a first arc centered on the rotation center between the end point X1 and the end point A1, and the at least two continuous straight lines between the end point A1 and the end point Z1. The motor according to claim 1, wherein the motor is located inside a circle obtained by extending the first arc with the same curvature. The cross-sectional shape of the outer rotor yoke is a second arc centered on the rotation center between the end point X2 and the end point A2, and the at least two continuous straight lines between the end point A2 and the end point Z2. The motor according to claim 1, wherein the motor is located outside a circle obtained by extending the second arc with the same curvature. 2. The motor according to claim 1, wherein the predetermined angle θ <b> 1 and the predetermined angle θ <b> 2 are both in an electrical angle range of 15 ° <θa <75 °. The intersection of at least two continuous straight lines connecting the end point A1 and the end point Z1 and the intersection of at least two continuous straight lines connecting the end point A2 and the end point Z2 are both convex. Item 1. The motor according to Item 1. The motor according to claim 1, wherein both the inner permanent magnet insertion hole and the outer permanent magnet insertion hole have gap portions at both circumferential ends. By adjusting the size of the inner slot opening that is the opening of the inner slot and the size of the outer slot opening that is the opening of the outer slot,
The motor according to claim 1, wherein the cogging torque by the inner rotor and the cogging torque by the outer rotor are in opposite phases. The motor according to claim 7 , wherein the cogging torque by the inner rotor and the cogging torque by the outer rotor are canceled out. An annular stator yoke, a plurality of inner teeth projecting radially inward from the stator yoke, a plurality of outer teeth projecting radially outward from the stator yoke in the same number as the inner teeth, and the inner side An inner slot configured between the teeth;
A stator core having an outer slot formed between the outer teeth, and a plurality of coils wound around the stator yoke between the inner slot and the outer slot and connected in a three-phase star or delta shape. A stator with
Including an inner rotor facing the inner teeth via a gap and an outer rotor facing the outer teeth via a gap, the inner rotor and the outer rotor being connected to the same rotating shaft,
The inner rotor has an inner rotor yoke having a plurality of inner permanent magnet insertion holes, and a plurality of inner permanent magnets embedded in the inner permanent magnet insertion holes,
The outer rotor has an outer rotor yoke having a plurality of outer permanent magnet insertion holes, and a plurality of outer permanent magnets embedded in the outer permanent magnet insertion holes,
A magnetic pole center line connecting the rotation center of the rotating shaft, the magnetic pole center of the inner rotor, and the magnetic pole center of the outer rotor, and a magnetic flux connecting the rotation center of the rotating shaft, the magnetic flux boundary of the inner rotor, and the magnetic flux boundary of the outer rotor. Both boundaries are straight lines,
A point where the magnetic pole center line intersects the outer shape of the inner rotor yoke is an end point X1, and a point where the magnetic pole center line intersects the inner shape of the outer rotor yoke is an end point X2.
A point where the magnetic flux boundary line intersects the outer shape of the inner rotor yoke is an end point Z1, and a point where the magnetic flux boundary line intersects the inner shape of the outer rotor yoke is an end point Z2.
A point at which a straight line having a predetermined angle θ1 in the direction of the magnetic pole boundary line from the magnetic pole center line and passing through the rotation center intersects the outer shape of the inner rotor yoke is defined as an end point A1.
When the end point A2 is a point having a predetermined angle θ2 in the direction of the magnetic pole boundary line from the magnetic pole center line and passing through the rotation center and intersecting the inner shape of the outer rotor yoke,
The cross-sectional shape of the inner rotor yoke is connected by at least two continuous straight lines between the end point A1 and the end point Z1, and the cross-sectional shape of the outer rotor yoke is at least 2 between the end point A2 and the end point Z2. Connected by two continuous straight lines,
By adjusting the size of the inner slot opening that is the opening of the inner slot and the size of the outer slot opening that is the opening of the outer slot,
A motor in which the cogging torque by the inner rotor and the cogging torque by the outer rotor are in opposite phases. The motor according to claim 9, wherein the cogging torque by the inner rotor and the cogging torque by the outer rotor are canceled out.

Images