JPH10257700A - Rotor core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sufficient reluctance torque by providing a plurality of slits that are arranged in a row in a radial direction, so that they project at a rotor center side and a q-axis magnetic flux cutting part whose width B wider in the radial direction of the rotor than the slits. SOLUTION: A disk-shaped core sheet 1 is made of a high-permeability material, such as an electromagnetic steel plate. Arc-shaped strips being curved so that a center side projects are arranged in a row, while sandwiching a slit 3 in a radial direction at four locations with an equal interval in its peripheral direction. A strip 2 is preferably of arc shape, considering for example, the shape of a magnetic path and the machining of the core sheet 1. When the width of the strip 2 is increased and the slit width is also increased, the strip width also decreases and the amount of d-axis magnetic flux that flows also decreases. Therefore, a slit, namely a KK slit 7, with a larger width that becomes a q-axis magnetic flux cutting part with a width larger than those of other slits is provided inside a plurality of slits.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor core structure of a reluctance motor utilizing reluctance torque.

[0002]

2. Description of the Related Art Reluctance motors have attracted attention as driving motors for electric vehicles, machine tools, and the like because they have the characteristic that secondary copper loss of a rotor does not occur as compared with inductance motors. However, this type of motor generally has a poor power factor, and for industrial use, it is necessary to improve the rotor core structure or the driving method. In recent years, a technique has been developed to improve the power factor by providing a multilayer flux barrier on the core sheet of the rotor core (1996, National Institute of Electrical Engineers of Japan, 1029, Honda et al., “Multi-flux barrier type synchronous reluctance motor Considerations ”).

FIG. 16 shows an example of a rotor core structure of the conventional improved reluctance motor. FIG. 16 (a)
In, the disk-shaped core sheet 161 made of an electromagnetic steel sheet,
A multilayer flux barrier 162 is formed in an arc shape with respect to the axis 163 of the core sheet 161. The flux barrier 162 is formed of a slit (through groove) having a width of about 1 mm, and is formed by press working. In addition, core sheet 1
A connection ring 164 having a constant width is provided on the outer circumference of the cylinder 61 so as to have strength against centrifugal force applied during rotation.

By stacking several tens of core sheets 161 in the direction of the rotor shaft 165, a rotor core 166 as shown in FIG. 16B is completed. This rotor core 166 is connected to a stator 167 as shown in FIG.
Is set in the plurality of field portions 16 of the stator 167.
8, a rotating magnetic field is applied to the rotor core 166, thereby generating a reluctance torque T. This reluctance torque T is expressed by the following equation.

T = Pn (Ld−Lq) id iq... (1) where Pn is the number of pole pairs, Ld and Lq are d and q-axis inductances, and id and iq. Is the d- and q-axis currents. The above (1)
It can be seen from the equation that the performance of the motor depends on the difference Ld-Lq between the d and q axis inductances. Therefore, in order to increase the difference Ld-Lq, the flux barrier is provided to provide resistance to the magnetic path in the q-axis direction crossing the slit, while securing the magnetic path in the d-axis direction sandwiched between the slits. Was.

[0006]

In the above-mentioned conventional configuration,
The slit with a width of about 1 mm is cut out by pressing. The outer end of the slit connects the strips with a constant width. However, in such a configuration, since the magnetic flux in the q-axis direction passes through each slit, the value of Lq increases and T decreases. This greatly affects the efficiency of the relatance motor. In order to reduce the magnetic flux in the q-axis direction by increasing the slit width of each slit, on the contrary, the width of the strip becomes narrow, the value of Ld becomes small, and the value of T also becomes small.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the conventional configuration, and provides a rotor core that rotates by utilizing reluctance torque that can improve the performance of a motor by obtaining sufficient reluctance torque. The purpose is to do.

[0008]

According to the present invention, there is provided a rotor core comprising:
By providing a plurality of slits arranged in the radial direction so as to protrude toward the center of the rotor, and a q-axis magnetic flux cutting portion having a wider width in the radial direction of the rotor than the plurality of slits and arranged inside the rotor. Lq can be reduced without changing the width of the strip, and the value of Ld / Lq can be increased.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotor core according to the present invention has a plurality of slits arranged in a radial direction so as to protrude toward the center of the rotor, and disposed inside the rotor from the plurality of slits. A q-axis magnetic flux cutting portion having a large width, and the q-axis magnetic flux cutting portion blocks the magnetic flux in the q-axis direction. Further, since the width of the strip through which the d-axis magnetic flux flows is not reduced, the amount of magnetic flux in the d-axis magnetic flux direction does not decrease. Therefore, Ld / Lq can be increased. Further, the width of the q-axis magnetic flux cutting portion is preferably at least 1.2 times the width of the other slits.

Further, the length of the q-axis magnetic flux cutting portion is preferably at least 0.9 times the length of the other slits. Because, if the length of the q-axis magnetic flux cutting part is too short,
The magnetic flux in the q-axis direction leaks from the outer peripheral end of the slit of the q-axis magnetic flux cutting portion. Therefore, the length of the q-axis magnetic flux cutting portion is set to be equal to the length of the other slits in order to prevent leakage of the q-axis magnetic flux.
9 times or more is required.

Further, since the width of the q-axis magnetic flux cutting portion is increased from the end to the center, the width of the slit is small at the rotor end face, the magnetic flux in the d-axis direction is easily input, and the center of the slit is The amount of magnetic flux in the q-axis direction of the portion can be reduced.

Further, it is preferable that the q-axis magnetic flux cutting portion is a gap in which the width in the radial direction of the rotor is three times or more at the center portion and at least one time at the end portion than the slit.

Further, the q-axis magnetic flux cutting portion may be an air gap. Further, in a rotor core obtained by laminating core sheets in which strips are arranged in the radial direction so as to be convex toward the center side in the rotor axial direction, the width of the slit outer peripheral end provided in the stress concentration portion of the core sheet is different from that of the other. By making the slit wider than the width of the outer peripheral end, even if the force due to centrifugal force concentrates on the stress concentration part, the rotor core has the width of the outer peripheral end enough to withstand this force, so the rotor core is There is no deformation.

Further, since the magnetic flux is saturated at the width of the other outer peripheral end and the magnetic flux does not flow to the outer peripheral end, the inductance ratio of Ld / Lq can be kept high. The stress concentration portion is determined by the radius, the material, the number of rotations, and the like of the rotor, and may be the slit at the most central side of the core sheet. Further, the stress concentration portion may be a slit on the most central side of the core sheet and a second slit on the central side. Further, the stress concentration portion may be the most central side of the core sheet, the second slit, and the third slit.

Furthermore, by making the slit end curved, the slit end has an R, and the strength of the slit further increases.

Further, by providing a bridge between adjacent strips, each slit is connected,
The strength of the rotor increases.

Further, when the core sheet is excited,
By connecting the strip and the bridge portion so that a meandering magnetic path is formed between the strip of the core sheet and the bridge portion, the timing resistance in the q-axis direction is increased and Ld / Lq is reduced. Can be.

Further, by filling the resin in the slit, the strength of the rotor is increased. Further, the rotor core has a core sheet A having an outer peripheral portion in the same direction as the q-axis direction.
And a core sheet B in which an outer peripheral portion in the same direction as the q-axis direction is cut out.
Is generated in the core sheet B.
Since the magnetic path in the axial direction crosses the notched portion, the resistance to the magnetic path in the q-axis direction increases, but the magnetic path in the d-axis direction is secured in the core sheet B. Almost the same. Therefore, the ratio Ld / Lq of the d-axis and q-axis inductances can be increased, so that the reluctance torque can be increased. Further, the core sheets A and the core sheets B may be arranged alternately.

Further, when laminating a plurality of core sheets, skew may be applied by shifting the mounting position of each core sheet in the rotor axis direction.

Further, since the q-axis magnetic flux cutting portion is a gap zone in which the width in the rotor radial direction is wider than a plurality of slits arranged in the radial direction, the magnetic flux in the q-axis direction can be totally shut off. In addition, since the rotating shaft supporting portion is provided inside the q-axis magnetic flux cutting portion, the rotating shaft can be securely fixed.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the following embodiments are merely examples embodying the present invention, and do not limit the technical scope of the present invention.

Embodiment 1 In FIG. 1, reference numeral 1 denotes a disc-shaped core sheet made of a material having high magnetic permeability such as an electromagnetic steel sheet.
In the circumferential direction, arc-shaped strips curved so as to protrude toward the center side at four equally-spaced positions are arranged in a row in the radial direction with the slit 3 interposed therebetween. Such a core sheet 1 is formed by press working or laser processing. The shape of the strip 2 is preferably an arc shape in consideration of the shape of the magnetic path, the processing of the core sheet 1, and the like. However, it is needless to say that the shape may be V-shaped or U-shaped. After several tens of core sheets 1 are stacked in the direction of the rotor shaft 4 to form a laminate 5, the rotor core 6 is completed by inserting the rotor shaft 4. Such core sheets 1 are integrally fixed with an adhesive or the like as necessary.

When the completed rotor core 6 is set in a stator (not shown), a rotating magnetic field is applied to the rotor core 6 from a field portion including a plurality of teeth of the stator, thereby generating reluctance torque. . That is, in the reluctance motor having such a rotor 6, when the inductance Lq in the q-axis direction crossing the strip 2 and the inductance Ld in the d-axis direction along the strip 2, are as follows. That is, the magnetic permeability in the q-axis direction is about 1/10 that of the magnetic steel sheet.
Since the resistance is given to the magnetic path by the slit 3 of the air layer which is 00, the magnetic flux hardly passes, and the inductance Lq becomes small. On the other hand, in the d-axis direction, the strip 2
Form a magnetic path, so that the magnetic flux easily passes and the inductance Ld increases.

Conventionally, even if a plurality of such slits 3 are provided, only a small amount of magnetic flux may pass through the slits 3. Therefore, it is conceivable to reduce the magnetic flux in the q-axis direction by increasing the thickness of each slit 3, but the width of each strip 2 is reduced and the flow of the d-axis magnetic flux is reduced. And then there strip 2
When the width of the slit is increased and the width of the slit is also increased, the width of the strip becomes smaller, and the amount of the d-axis magnetic flux also decreases. Therefore, in the first embodiment, q that is wider than the other slits inside the plurality of slits
Wide slit, KK slit 7 to be used as shaft magnetic flux cutting part
Was provided.

The KK slit 7 will be described with reference to FIGS. The slits 3 are arranged in line toward the center of the rotor. A large slit 7 serving as a q-axis magnetic flux cutting portion is provided on the center side of the plurality of slits 3. This large slit 7 has a wider slit width S in the rotor radial direction than the other slits 3. Further, the length of the large slit 7 is substantially the same as the length of the longest slit, ie, the innermost slit 2, and is in an arc shape.

FIG. 3 shows the outer peripheral portion of the core sheet 1. The interval between the slit 3 and the outer portion of the rotor core 6 is a slit outer peripheral end portion 10. In this rotor core, the strips 2 are connected only by the slit outer peripheral end portions 10. The innermost slit outer peripheral end 4a connecting the strips 2 and the second innermost slit outer peripheral end 4b are stress concentration portions 11, and the widths L1 and L2 of the slit outer peripheral ends 4a and 4b. Is the same width in portions other than the stress concentration portion 11, but is wider in the stress concentration portion 11 than in other slit widths. The stress concentration portion at this time is a point where the force acting on the slit outer peripheral end is the largest, and the slit outer peripheral end of the stress concentration portion has a larger number of supporting strips and a greater force due to centrifugal force,
In addition, a force is applied to the outer side of the rotor by the centrifugal force, and the strip tries to be straight, and the end of the strip pushes the outer peripheral end of the slit, so that a force is further applied to the outer peripheral end of the stress concentration portion. In other words, the stress concentration portion
The outer peripheral end of the slit inside the rotor is the outer peripheral end of the large slit 7 in the first embodiment. The number of stress concentration portions is determined by the size of the rotor, the rotation speed, and the like.

As described above, by making the widths L1 and L2 of the outer peripheral end of the stress concentration portion 11 wider than the widths of the other ends, the rotor can be rotated at a high speed. That is, the centrifugal force generated by the rotation of the rotor becomes larger toward the center of the rotor. Therefore, even if the force is concentrated on the stress concentration portion 11 inside the rotor, the width L of the outer peripheral edge of the slit of the stress concentration portion 11 is increased.
Since 1 and L2 are wide, they can withstand the centrifugal force caused by high-speed rotation. Further, the slit outer peripheral end portion 10 other than the stress concentration portion 11
In this case, since the centrifugal force generated by the rotation of the rotor is smaller than the stress concentration portion, the width of the slit outer peripheral end can be reduced. As described above, if the width of the slit outer peripheral portion other than the stress concentration portion is reduced, the d-axis magnetic flux does not flow in the q-axis direction via the slit outer peripheral end due to magnetic saturation.

That is, regarding the magnetic flux in the q-axis direction, no magnetic flux flows in the q-axis direction by each slit, but since the large slit 7 is wider than the other slits, the q-axis magnetic flux is further reduced. Lq can be reduced.
At this time, since the large slits 7 are provided inside the rotor from the respective strips 2, the width of each strip is not reduced. Therefore, the magnetic flux in the d-axis direction passes through each strip and flows in the d-axis direction. That is, the value of Ld does not decrease. Therefore, the value of Ld / Lq increases, and T can be reduced.

Further, by connecting the strips only at the outer peripheral end of the slit, the magnetic flux flowing in the d-axis direction flows smoothly, and the connecting portion of each strip is only at the outer peripheral end of the slit. Magnetic flux leakage is further reduced. That is, the value of Ld / Lq further increases.

The width of the large slit 7 at this time is at least three times wider at the center than the widths of the other slits, and this is determined by the size of the rotation axis of the rotor core. Therefore, if the rotation axis is small, the width of the KK slit can be further increased.

Further, the center of the rotor core is hollow or filled with resin (the portion surrounded by the innermost strip is defined as a gap), and the end face of the rotor core is clamped by a fixture having a rotating shaft protruding. May be. That is,
By making the inside of the innermost strip hollow, Lq can be further reduced.

It is preferable that the width of the large slit 7 is particularly wide at the center of the rotor. This is because if a wide width is taken at the end of the slit, the input surface of the magnetic flux in the d-axis direction becomes small. In other words, if the width of the end of the large slit is as large as the width of the center, the width of the input portion of the d-axis magnetic flux also decreases, and the value of Ld decreases. The length of the large slit 7 is suitably at least 0.9 times the length of the longest slit. If the length is too short, the q-axis magnetic flux leaks from the outer peripheral end of the large slit, and the value of Ld / Lq decreases.

Although the stress concentration portion is the outermost end of the slit on the most central side, the stress concentration portion is considered second to the outermost end of the slit on the most central side in consideration of the rotation speed, the material, and the width of the outer peripheral end of the slit. The slit outer peripheral end on the center side may be used, the stress concentration portion may be the most central side, the second central side, the third central outer side slit outer peripheral end, and the stress concentration portion may be more slit outer peripheries. It may be an end.

By using such a rotor core for an electric motor, high rotation and high torque can be achieved, and when used for an electric vehicle, a compressor, an air conditioner or the like, high performance and high output can be achieved.

Further, the slits 3 between the strips 2 of the core sheet 1 may be sealed with resin. Specifically, resin may be put in the slits 3 of the core sheet 1 and solidified.
By doing so, the rotational strength of the core sheet 1 can be increased without providing a bridge portion.
Other low-permeability materials such as aluminum and hard rubber may be used for the sealant.

In FIG. 2, the width L1 of the slit outer peripheral end 4a is such that the rotor inner side r1 at the slit outer peripheral end and the rotor outer side r2 at the slit outer peripheral end have a relationship of r1 = r2. The rotor inner side r3 at the outer peripheral end of the slit of the end 4b and the rotor outer side r4 at the outer peripheral end of the slit
Is r3 = r4. Similarly, the lengths of the rotor inner side and the rotor outer side at the outer peripheral end of the other slits are the same for each slit. That is, r1 = r2> r3 = r4> r5 =
r6 = r7... However, as shown in FIG. 4, the width of the slit outer peripheral end is larger on the outer side of the slit outer end than on the inner side, and r1>r2>r3>r4> r5 = r6 =
r7...

The relationship that the width of the slit outer peripheral end is wider than the width of the adjacent slit outer peripheral end may be not only the stress concentration portion but also the slit of the entire rotor. Specifically, as shown in FIG. 5, L1 ≧ L2 ≧ L3 ≧ L5 ≧
.., Or r1 ≧ r2 ≧ r3r ≧ 4
r ≧ 5 ≧ r6 ≧...

In the motor using such a rotor core, no secondary copper loss of the rotor occurs, so that the compressor,
Suitable for use in air conditioners, refrigerators, and electric vehicles.

(Embodiment 2) FIG. 6 is a front view of the core sheet 41. FIG. The slits 43 are arranged in line toward the center of the rotor, and among the plurality of slits 43, the slit 43 located closest to the center is a large slit 47.
This large slit 47 is located closest to the center of the rotor,
This slit width is wider than the other slit widths.

The innermost slit outer peripheral end 44a and the second innermost slit outer peripheral end 44b, which are stress concentration portions
Is shorter than the width of the other slit outer peripheral end. And the width 44a of the slit outer peripheral end is the slit outer peripheral end 44b.
Greater than the width of. Further, a bridge portion 45 is provided between the strips so as to connect the strips. By increasing the width of the slit outer peripheral end portion of the stress concentration portion and providing the bridge portion 45 in this manner, even if a centrifugal force generated when the rotor is rotated at a high speed is generated, the strength of the rotor is increased. It can withstand high-speed rotation of the rotor.

More specifically, when the core sheet is excited, the strip 42 and the bridge portion 45 are connected to each other so that a meandering magnetic path is formed by the strip 42 and the bridge portion 45 of the core sheet 41. I do. Each bridge portion 45 is formed such that the distance between the connection points between the strip 42 and the bridge portion 45 becomes longer toward the inner peripheral side of the core sheet. Each of the bridge portions 45 is arranged such that the connection points between the strips 42 and the bridge portions 45 are alternated between adjacent strips 42.
To form With these, the rotational strength of the core sheet 41 can be ensured, and when the core sheet 41 is excited, the magnetic path in the q-axis direction generated in the core sheet 41 is elongated, and the magnetic path in the q-axis direction is reduced. The resistance can be increased.

Here, if the meandering magnetic path is formed in one core sheet 41, the magnetic path in the q-axis direction is lengthened in a plane to reduce the resistance to the magnetic path in the q-axis direction. Although it can be increased, the magnetic flux may be saturated in one core sheet 41 and the meandering magnetic path may not be formed in some cases. If the meandering magnetic paths are formed in the rotor axis direction between the core sheets 41 by laminating the core sheets 41 in the rotor axis direction, the magnetic flux is unlikely to be saturated, and the meandering magnetic paths are three-dimensionally formed. Therefore, the resistance to the magnetic path in the q-axis direction can be increased by lengthening the magnetic path in the q-axis direction.

Furthermore, if each bridge 45 is formed so that the width of the bridge 45 is smaller than the width of the strip 42, the magnetic path in the q-axis direction can be narrowed.
Also in this case, the resistance to the magnetic path in the q-axis direction increases, so that the same operation and effect as described above can be obtained. If each bridge portion 45 is formed such that the width of the bridge portion 45 becomes wider toward the inner peripheral side of the core sheet 41, the core sheet 41
The strength according to the distribution state of the centrifugal force at the time of rotation can be secured.

FIG. 7 shows a state in which a magnetic path in the d-axis direction generated in the core sheet 41 when the core sheet 41 is excited is formed. The large slit 47 located between the peripheral strips 42 has almost no magnetic path in the d-axis direction. On the other hand, the magnetic path in the q-axis direction in FIG. Therefore, if the core sheet 41 is formed so that the width of the large slit 43 is larger than the width of the other slits 43, almost only the magnetic path in the q-axis direction crosses the large slit 43, so that the d-axis The resistance to the magnetic path in the q-axis direction can be increased without affecting the resistance to the magnetic path in the direction, and a greater effect can be obtained.

Further, d generated on the core sheet 41
The magnetic path in the axial direction is formed only slightly in the outer peripheral portion in the q-axis direction as compared with the center side. Therefore, as shown in FIG. 9, if the outer peripheral portion 49 in the q-axis direction is deleted, almost only the magnetic path in the q-axis direction crosses the deleted portion.
With little effect on the resistance to the axial magnetic path, q
Only the resistance to the magnetic path in the axial direction can be increased, and a greater effect can be obtained.

However, as shown in FIG. 10, if a connecting ring 50 for connecting only the outer periphery in the q-axis direction of the magnetic path generated in the core sheet is provided, the slightly formed d-axis Since the magnetic path can be secured, the resistance to the magnetic path in the d-axis direction can be slightly reduced. Since the connecting ring 50 here is not a strength member, unlike the connecting ring of the conventional example, it is desirable that the radial width of the core sheet be as thin as possible in processing.

Further, from the viewpoint of securing the strength against the centrifugal force when the core sheet 41 rotates, a bridge for linearly connecting the strips 42 arranged in the q-axis direction of the magnetic path generated in the core sheet 41. It is desirable to provide the part 11.

When the bridge portion 45 is formed so that the inside of the core sheet 41 is thick and the outer peripheral side is thin, the mass at the front end portion is small, which is advantageous in terms of imbalance strength. If the width of the bridge portion 45 is formed to be larger than the width of the strip 42 at least on the center side of the core sheet 41, sufficient strength for practical use can be secured. When a plurality of bridge portions are provided, it is desirable to provide the bridge portions symmetrically in terms of unbalance strength. With these, the core sheet 4
Since the rotation strength of the motor 1 can be increased, a motor that can withstand higher-speed rotation can be realized.

Although the core sheet 1 shown in FIG. 6 is an example in which all of these measures are applied, it is a matter of course that a part thereof may be applied. Such specific examples are shown in FIGS.
(F). The number of the KK slits forming the q-axis magnetic flux portion is not limited to one in the deformation direction of the rotor as shown in the figure, but may be plural.

Third Embodiment FIGS. 12 and 13 are front views of a rotor according to a third embodiment. In a rotor core structure of a reluctance motor in which core sheets made of a magnetic permeability material are laminated in the rotor axis direction, the width of the slit outer peripheral portion of the stress concentration portion having the outer peripheral portion in the same direction as the q-axis direction is changed to the outer peripheral edge of the other slit. A core sheet A81 wider than the width of the portion, and a core sheet B82 in which the outer peripheral portion in the same direction as the q-axis direction is cut out,
A core sheet B is interposed between the core sheets A. Further, a large slit having a width wider than the slit width of the other slits is provided inside the innermost slit of the core sheet A81.

According to the above configuration, when the core sheet is excited, the core sheet B82 has a cutout in the outer periphery in the same direction as the q-axis direction of the magnetic path generated in the core sheet A81.
Is sandwiched between the core sheets, the magnetic path in the q-axis direction generated in the core sheet crosses the notched portion, so that the resistance to the magnetic path in the q-axis direction increases.
Since the magnetic path in the d-axis direction is also secured in the core sheet B82, the resistance to the magnetic path in the d-axis direction hardly changes. Therefore, the ratio Ld / L of the d and q axis inductances
Since q can be increased, reluctance torque can be increased. Thus, a sufficient reluctance torque can be obtained, and the motor performance can be improved.

More specifically, the core sheets A81 and the core sheets B82 are alternately arranged. Alternatively, the core sheets B82 may be sandwiched between a plurality of core sheets A.

As shown in FIGS. 14A and 14B, the core sheet 82 is sandwiched between core sheets 81. The shape of the core sheet is as shown in FIG. Outer peripheral portion 8 in the same direction as the q-axis direction of the magnetic path generated in core sheet 81 when 81 is excited
Use one with 3 notched. The core sheet 82 may be arranged such that core sheets 81 and core sheets 82 are alternately arranged as shown in FIG. 14 (a), or as shown in FIG. 14 (b). The sheet 81 may be sandwiched.

As described above, by sandwiching the core sheet B82 between the core sheets A81, the magnetic path in the q-axis direction generated in the core sheet A81 when the core sheet A81 is excited is formed by cutting off the outer peripheral portion. To cross q
Although the resistance to the magnetic path in the axial direction increases, the magnetic path in the d-axis direction is secured in the core sheet B82, so that the resistance to the magnetic path in the d-axis direction hardly changes. Therefore, since the ratio Ld / Lq of the d and q axis inductances can be increased, the reluctance torque can be increased.

Embodiment 4 When stacking a plurality of core sheets each having a KK slit whose innermost slit is wider than the other slits, the mounting position of each core sheet is shifted in the rotor axis direction to reduce skew. If this is done, the resistance to the magnetic path in the d-axis direction is made uniform in the circumferential direction of the rotor, so that the magnetic flux in the d-axis direction that enters the rotor from the stator and exits from the rotor to the stator becomes uniform, resulting from the nonuniform magnetic flux The motor ripple can be reduced, and the motor performance can be further improved.

In this case, the skew may be stepped, or the skew may be a skew amount equal to or less than the pitch of the teeth of the stator.

When laminating a plurality of core sheets, FIG.
As shown in FIG. 5 (a), if the mounting position of each core sheet 91 is shifted in the rotor axis direction and the skew 97 is applied,
Since the resistance to the magnetic path in the d-axis direction is made uniform in the circumferential direction of the rotor, the magnetic flux in the d-axis direction that enters the rotor core 96 from the stator or exits from the rotor core 96 to the stator is made uniform, resulting from the non-uniform magnetic flux. The torque ripple can be reduced to further improve the motor performance.

In this case, as shown in FIG. 15B, the skew 97 is formed in a step shape, or
As shown in (c), a V-shape that is bent in the middle of the rotor shaft 94 may be used. According to the experience of the present inventors, it is preferable that the skew 47 has a skew amount equal to or less than the pitch of the teeth 92 of the stator.

As described above, by applying an appropriate skew 97 to the rotor core 46 side, the motor performance can be further improved. It is well known that even when skew is applied to the stator side, torque ripple can be reduced in the same manner as described above to further improve motor performance.

[0060]

According to the present invention, claims 1, 2, 3, 4, 5, 6,
According to the inventions described in 7, 16, and 17, since Ld can be maintained at a high value and can be reduced, high-speed rotation can be performed while maintaining the inductance ratio of Ld / Lq high. Therefore, a high-efficiency, high-output motor can be provided.

Further, according to the fifth and sixth aspects of the present invention, since the slit width near the outer peripheral portion of the rotor is narrow, d from the stator is reduced.
Since the axial magnetic flux easily enters the rotor, Ld can be increased, and T of the electric motor can be increased.

Further, the invention according to claims 8 and 9 can provide a motor capable of high-speed rotation since the slit width is increased only in the stress concentration portion.

Further, according to the tenth aspect of the present invention, the point where the strips are connected is only at the outer peripheral end of the slit, and the ratio of Ld / Lq can be kept high. Can be.

Further, according to the eleventh aspect of the present invention,
By providing the bridge portion, high-speed rotation can be achieved.

Further, according to the twelfth aspect of the present invention, by obtaining an R-shape at the slit end, the strength is increased and high-speed rotation is possible.

Further, according to the thirteenth aspect, the magnetic flux resistance in the q-axis direction increases, and Lq can be further reduced.

Further, according to the invention of claim 14, the strength is increased and high-speed rotation is possible. Furthermore, the invention according to claim 15 can provide a motor with higher efficiency and higher output by using different core sheets.

Further, the invention of claim 16 can reduce cogging torque.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a reluctance motor according to a first embodiment of the present invention.

FIG. 2 is a plan view of the core sheet.

FIG. 3 is a partially enlarged view of the core sheet.

FIG. 4 is a plan view of the core sheet.

FIG. 5 is a plan view of the core sheet.

FIG. 6 is a plan view of a core sheet according to the second embodiment.

FIG. 7 is an explanatory view showing a magnetic path of the core sheet.

FIG. 8 is an explanatory view showing a magnetic path of the core sheet.

FIG. 9 is an enlarged view of the main part.

FIG. 10 is an enlarged view of the main part.

FIG. 11 is an enlarged view of the main part.

FIG. 12 is a plan view of the core sheet A of Example 3;

FIG. 13 is a plan view of the core sheet B.

FIG. 14 is a sectional view of the rotor core.

FIG. 15 is a sectional view of a rotor core according to the sixth embodiment.

FIG. 16 is a diagram showing a conventional rotor core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core sheet 2 Strip 3 Slit 4 Rotor shaft 5 Laminated body 6 Rotor core 7 KK slit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Sawada 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (18)

[Claims] 1. A plurality of slits arranged in the radial direction so as to project toward the center of the rotor, and a q-axis magnetic flux cutting section which is arranged inside the rotor from the plurality of slits and has a width in the rotor radial direction larger than the slits. And a rotor core comprising: 2. The rotor core according to claim 1, wherein the width of the q-axis magnetic flux cutting portion is at least 1.2 times the width of the other slits. 3. The rotor core according to claim 1, wherein the q-axis magnetic flux cutting portion is a gap zone having a width in the rotor radial direction wider than a plurality of slits arranged in the radial direction. 4. The rotor core according to claim 3, wherein the length of the q-axis magnetic flux cutting portion is at least 0.9 times the length of the longest slit. 5. The rotor core according to claim 1, wherein the width of the q-axis magnetic flux cutting portion increases from an end to a center. 6. The rotor core according to claim 1, wherein the q-axis magnetic flux cutting portion is a gap having a width in the radial direction of the rotor that is three times or more greater than that of the slit at the center and one or more times greater at the ends. 7. The rotor core according to claim 1, wherein the q-axis magnetic flux cutting portion is a gap. 8. A rotor core formed by laminating core sheets in which strips are arranged in the radial direction so as to project toward the center side in the rotor axial direction, wherein the width of the slit outer peripheral end provided in the stress concentration portion of the core sheet is reduced. 3. The rotor core according to claim 1, wherein the width of the outer peripheral end of the other slit is wider than that of the other slit. 9. The stress concentration portion is the innermost slit outer peripheral end of the rotor and the second innermost slit outer peripheral end, and the width of the innermost slit outer peripheral end is the second innermost slit. 9. The rotor core according to claim 8, which is wider than a width of the outer peripheral end. 10. The rotor core according to claim 8, wherein the strips are connected only by the outer peripheral edge of the slit. 11. The rotor core according to claim 1, wherein a bridge portion connecting adjacent strips is provided in the slit. 12. The rotor core according to claim 1, wherein the slit ends are curved. 13. The rotor core according to claim 12, wherein when the core sheet is excited, the strip and the bridge are connected to form a meandering magnetic path between the strip and the bridge of the core sheet. . 14. The rotor core according to claim 1, wherein a resin is filled in the slit. 15. The rotor core includes a core sheet A having an outer peripheral portion in the same direction as the q-axis direction, and a core sheet B having a notched outer peripheral portion in the same direction as the q-axis direction. 2. The rotor core according to claim 1, wherein a core sheet B is sandwiched between the cores. 16. The rotor core according to claim 1, wherein, when laminating a plurality of core sheets, the mounting positions of the core sheets are shifted in the rotor axis direction to skew. 17. The rotor core according to claim 1, wherein the q-axis magnetic flux cutting portion is a gap surrounded by a strip located closest to the center of the rotor among strips forming a plurality of slits. 18. An electric motor comprising the rotor core according to claim 1.