JP2000166198A - Reluctance motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress cost increase caused by forming slits in the salient poles of stacked plates as low possible. SOLUTION: In order to form slits 3 at a low coat, the slits 3 are formed by press machining using a die instead of laser machining. The thickness of a stacked plate 1 is not larger than 5 times of the maximum width of the slit 3 to extend a die life. With this constitution, the cost for the die can be reduced and the manufacturing cost of the stacked plates 1 in which the slits 3 are formed can be suppressed. When the stacked plates 1 are subjected to press machining, the slits 3 are formed simultaneously, so that the increase in the number of processes for forming the slits 3 can be eliminated and the increase of the cost can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-phase, single-wave reluctance motor.

[0002]

2. Description of the Related Art A reluctance motor has the advantages of a large output torque and a simple structure, but has the disadvantage of generating high torque ripple, and has been used only in some fields until now. I have.

[0003]

Japanese Patent Laid-Open Publication No. Hei 8-126273 discloses a method of inserting a slit inside a salient pole of a rotor in order to reduce high torque ripple. However, in order to insert the slit into the salient pole, a new process for forming the slit is required, which causes a problem that the cost is increased. A first object of the present invention is to provide a reluctance electric motor capable of minimizing an increase in cost caused by inserting a slit into a salient pole.

In a small motor having a small salient pole width, the width and number of slits that can be inserted are limited due to manufacturing restrictions and restrictions on suppressing output torque reduction, and torque ripples occur in synchronization with the slits. However, there was a problem that the torque ripple could not be sufficiently reduced. Second embodiment of the present invention
It is an object of the present invention to provide a reluctance motor that can reduce torque ripple even in a small motor having a small salient pole width.

[0005]

According to the first aspect of the present invention, it is possible to prolong the life of a mold in which a slit or a groove is formed in a salient pole of a laminated plate by press working. Since the cost required for the mold can be reduced as described above, the manufacturing cost of the laminated plate having the slits and grooves can be reduced. That is, the cost of the reluctance motor in which the slit or the groove is inserted in the salient pole can be reduced.

By adopting the means of claim 2 and forming the slit as an open slit extending to the outer end of the salient pole, the magnetic path at the tip of the salient pole is eliminated, and the flux barrier effect by the slit is increased, and the torque is increased. The effect of reducing ripples increases.

[0007] By adopting the means of claims 3 to 5, restrictions on the width and number of slits that can be inserted into the salient poles are relaxed. As a result, even in a small motor having a small salient pole width, the torque ripple synchronized with the slit is reduced, and the torque ripple can be sufficiently reduced. In particular, in claim 4, since the slits of the plurality of adjacent laminated plates are the same, a portion where the magnetic flux generated in the overlapping portion of the slits of the adjacent laminated plates is easy to flow is not formed, and the effect of reducing the torque ripple is increased.

[0008] By adopting the means of claim 6 and changing the front and back surfaces of the laminated plates, the errors of the salient poles in each laminated plate are absorbed, and as a result, the sectional area of each salient pole in the core is reduced. Be the same. By adopting the means of claim 6 and displacing the positions of the salient poles of the laminated plates so as to be overlapped, errors of the salient poles in each laminated plate are absorbed, and as a result, the sectional area of each salient pole in the core is the same. become. The type of the laminated plate (the type of the slit, the type of the used thin plate material, etc.) is adopted by adopting the means of claim 6.
Is changed, the error of each salient pole in each laminated plate is absorbed, and as a result, the cross-sectional area of each salient pole in the core becomes the same.

By adopting the means of claim 7, a sudden increase in the amount of magnetic field in the initial stage of the start of facing with the facing salient pole facing during rotation is moderated, and a sudden increase in the amount of magnetic flux in the initial stage of the start of facing is suppressed. Thus, the effect of reducing the torque ripple at the initial stage of the start of the opposition of the projections can be increased.

[0010] By employing the means of claim 8, a sharp decrease in the amount of magnetism in the latter half of the start of the opposition with the opposing salient poles facing during rotation is suppressed, and the magnetic saturation in the latter half of the start of the opposition is reduced. In addition, the effect of reducing torque ripple in the latter half of the start of projection opposition can be increased.

[0011]

Next, embodiments of the present invention will be described with reference to a plurality of examples. FIG. 1 shows a laminated plate 1 of a rotor and a laminated plate 2 of a stator in a reluctance motor. In this embodiment, as shown in FIG. 2, a plurality of slits 3 (or grooves) are formed in the salient poles 1a of the laminated plate 1 constituting the rotor core. The plurality of slits 3 extend outward from the center of rotation of the rotor.

A plurality of slits 3 provided in the salient pole 1a
Avoids forming by laser processing to manufacture at low cost,
It is formed by press working using a mold, and is preferably formed at the same time as press forming of the laminated plate 1 of the rotor, thereby suppressing an increase in the number of steps due to the formation of the slit 3.

Further, it is necessary to extend the life of the mold in order to suppress the manufacturing cost. FIG. 3 shows the relationship between the life of the mold and the thickness (b) of the laminate 1 divided by the slit width (a). The mold life is represented by the number of shots, and is determined by the increase in burrs at the time of punching and the entanglement of the punched pieces. As shown in the graph of FIG. 3, in order to extend the life of the mold, the thickness of the laminate 1 needs to be 5 times or less the maximum width of the slit.

The slit 3 of the reluctance motor adopting the present invention is provided such that the thickness of the laminated plate 1 is less than or equal to 5 times the maximum width of the slit.
The life of the mold that forms the slit 3 can be extended. Since the cost required for the mold can be reduced in this way, the manufacturing cost of the laminated plate 1 in which the slits 3 are formed can be reduced. That is, an increase in cost caused by forming the slit 3 in the salient pole 1a can be suppressed as much as possible. Further, by simultaneously forming the plurality of slits 3 when press-molding the laminated plate 1 of the rotor, it is possible to eliminate an increase in the number of processes due to the formation of the slits 3, thereby also suppressing costs. .

[Second Embodiment] In the second embodiment, as shown in FIG. 4, a plurality of slits 3 are formed only in salient poles 2a of a laminated plate 2 constituting a stator.

[Third Embodiment] In the third embodiment, as shown in FIG. 5, a plurality of slits 3 are formed in salient poles 1a of a laminated plate 1 constituting a rotor, and a laminated plate constituting a stator is formed. A plurality of slits 3 are also formed in the two salient poles 2a.

[Fourth Embodiment] This fourth embodiment shows a change in torque ripple according to the number of slits 3, and the stator shown in the first embodiment (see FIG. 2) has 12
The description will be made by using a reluctance type electric motor having eight slots and a rotor having eight poles (slit 3 is only on the rotor side). FIG.
The torque waveform when the position, the number, and the width of the slits 3 in the salient pole 1a of the rotor are the same. A solid line A is a case where there are 14 slits, and a solid line B is a case where there are seven slits. It is. As shown in FIG. 6, when the number of slits 3 is 7, the amount of torque ripple increases as compared with the number of slits 14. The purpose of this is to originally rectify the magnetic flux flow in the radial direction by inserting the slits 3 and increase the number of magnetic fluxes in proportion to the rotation angle. However, the rectification effect is reduced by reducing the number of the slits 3. This is because torque ripple increases and torque ripple increases.

[Fifth Embodiment] The fifth embodiment is suitable for use in a small motor having a small salient pole width. The rotor is obtained by alternately laminating two types of laminated plates (slit specification A and slit specification B) having different specifications of the slit 3.
The specifications of these two types of slits 3 are as shown in FIG.
The number and width of the slits 3 of the salient pole 1a are the same.
The location is different. FIG. 8 shows a torque waveform of a reluctance electric motor using the rotor provided as described above.
In the figure, the solid line A is the torque waveform according to the slit specification A,
Solid line B is a torque waveform according to slit specification B, and solid line C is a composite waveform. By alternately overlapping the salient poles 1a of the slit specification A and the slit specification B as in this embodiment, a large number of slits 3 are formed in the core salient pole even in a small motor having a small salient pole width. An equivalent torque ripple reduction effect can be obtained.

[Sixth Embodiment] In the sixth embodiment, as shown in FIG. 9, the salient poles 1 of the slit specification A and the slit specification B are used.
As shown in FIG. 10, the laminated plates 1 in which “a” are alternately arranged are alternately laminated while being shifted by one pole, and the same effect as in the fifth embodiment can be obtained.

[Seventh Embodiment] The seventh embodiment is different from the one shown in FIG.
As shown in FIG. 7, the slit 3 is provided in an open slit extending to the outer end of the salient pole 1a. In each of the embodiments described above, the slit 3 is a closed slit that extends only to the vicinity of the outer end of the salient pole 1a.
A magnetic path is formed at the tip of the magnetic flux, a magnetic flux flows into the magnetic path, and the flux barrier effect by the slit 3 tends to decrease. However, by making the slit 3 an open slit, a magnetic path is not formed at the tip of the salient pole 1a, and the flux barrier effect of the slit 3 increases. As a result, the magnetic path between the salient pole 1a and the opposing salient pole 2a is formed smoothly, and the effect of reducing torque ripple increases.

Eighth Embodiment FIGS. 12A and 12B are side views of a salient pole 1a obtained by laminating a laminate 1 having slits 3 provided in open slits. In addition, in the figure, the part shown by the x frame shows the air part by the slit 3,
The hollow part indicates the iron part constituting the salient pole 1a. FIG.
(A) is obtained by alternately stacking two types of laminated plates 1 and shifting the positions of the slits 3 for each laminated plate 1. In the overlapping portions of the slits 3 of the adjacent laminated plates 1, there are portions where magnetic flux easily flows. I can do it. Therefore, the magnetic flux flows to the adjacent laminated plate 1, and the effect of reducing the torque ripple by the slit 3 is reduced. Therefore, as shown in FIG. 12 (b), two types of laminated boards 1 are stacked in plurals, respectively.
The positions of the slits 3 are arranged so as to be different for each of the plurality of adjacent laminated boards 1, and the slits 3 of the same specification are arranged so as to overlap. Then, the magnetic flux flowing between the adjacent laminated plates 1 can be greatly reduced, and the effect of reducing the torque ripple by the slit 3 can be increased.

Ninth Embodiment FIGS. 13A and 13B are diagrams showing salient poles 1a. FIG. 13A shows an arrangement in which the widths of the slits 3 are equally divided at the same width. In the salient pole 1a provided with such a slit 3, torque ripple is reduced, and a torque waveform shown by a broken line in FIG. 14 is obtained. However, an abrupt increase in the amount of magnetism occurs at the beginning of the opposition to the opposing salient pole 2a that opposes during rotation, and the amount of magnetic flux rapidly increases at the beginning of the opposition to increase the torque. Further, in the latter half of the start of the opposition to the opposing salient pole 2a that is opposed to the rotor during rotation, the amount of magnetism sharply decreases, and magnetic saturation occurs in the latter half of the start of the opposition, thereby lowering the torque.

Therefore, as shown in FIG. 13B, the width of the slit 3 at the front end in the rotation direction with respect to the opposing salient pole 2a is increased, and the gap density of the slit 3 at the front end in the rotation direction is increased. Then, a sudden increase in the amount of magnetism at the beginning of the opposing operation is suppressed, and the amount of magnetic flux at the beginning of the opposing operation is reduced, so that the torque is reduced. Further, as shown in FIG. 13B, the width of the slit 3 at the rear end opposite to the salient pole 2a in the rotation direction is reduced, and the gap density by the slit 3 at the rear end opposite to the rotation direction is provided. Then
In the latter half of the opposing start, the magnetic saturation is suppressed and the torque increases.

That is, as shown in FIG. 13B, by providing a large gap density by the slit 3 at the front end facing in the rotation direction and by providing a small gap density by the slit 3 at the rear end facing the rotation direction, the solid line in FIG. The torque waveform shown in FIG. In this embodiment, an example in which the width of the slit 3 is changed to change the gap density of the slit 3 at the front end and the rear end facing the rotation direction, but the position of the slit 3 is changed or the number of the slits 3 is reduced. The slit 3 at the front end and the rear end facing the rotation direction by changing
The same effect as in the ninth embodiment can be obtained even when the void density is changed.

[Tenth Embodiment] FIG. 15 is a drawing showing salient poles 1a. The tenth embodiment is used for a reluctance motor that rotates in both forward and reverse directions. The width of the slits 3 at both ends of the salient pole 1a is increased, and the gap density due to the slits 3 at both ends of the salient pole 1a is reduced. It is provided largely. Thus, by providing the difference in the width of the slit 3 symmetrically, torque ripple in forward and reverse rotation can be reduced.
In this embodiment, an example in which the gap density by the slits 3 is changed by changing the width of the slits 3 is shown. However, by changing the position of the slits 3 or changing the number of the slits 3, the gaps by the slits 3 are changed. The density may be changed.

[Eleventh Embodiment] FIG. 16 shows a salient pole 1 obtained by laminating a laminate 1 having slits 3 provided in open slits.
FIG. In the drawing, a portion indicated by a x frame indicates an air portion formed by the slit 3, and a white portion indicates an iron portion forming the salient pole 1a. This eleventh embodiment is based on 2
A plurality of types of laminated boards 1 are respectively stacked, and two types of laminated boards 1
Is changed to change the void density by the slit 3. By doing so, the ninth aspect
The same effect as that of the embodiment can be obtained.

[Twelfth Embodiment] In the twelfth embodiment, two types of laminated plates 1 having different positions of the slits 3 are arranged in the same salient pole 1a. And the other slits 3 are arranged at equal intervals (a = b) as shown in FIG. When the interval between the slit 3 of one laminated plate 1 and the other slit 3 is provided at unequal intervals (a> b, a <b), the waveform of the torque with respect to the rotation angle is as shown in FIG. A small amount of torque ripple peaks and valleys occurs. However, when the gap between the slit 3 of one laminated plate 1 and the other slit 3 is provided at equal intervals (a = b), the peaks and valleys of the torque ripple are canceled, and the torque ripple generated by the slit 3 is further reduced. When possible, the peaks and valleys of the torque ripple are canceled as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a view showing a laminated plate of a rotor and a stator (first embodiment).

FIG. 2 is a partially enlarged view of FIG. 1 (first embodiment);

FIG. 3 shows the life of the mold and the plate thickness (b) / slit width (a).
6 is a graph showing the relationship with (first embodiment).

FIG. 4 is a view showing a laminated plate of a rotor and a stator (second embodiment).

FIG. 5 is a view showing a laminated plate of a rotor and a stator (third embodiment).

FIG. 6 is a graph showing a torque waveform (fourth embodiment).

FIG. 7 is a view showing salient poles having different slit specifications (fifth embodiment).

FIG. 8 is a graph showing a torque waveform (fifth embodiment).

FIG. 9 is a view showing a laminated plate of a rotor and a stator (sixth embodiment).

FIG. 10 is a view showing a stacked state of salient poles having different slit specifications (sixth embodiment).

FIG. 11 is a view of a salient pole provided with an open slit (seventh embodiment).

FIG. 12 is a view of a salient pole as viewed from a side (eighth embodiment).

FIG. 13 is a view showing slits of salient poles (ninth embodiment).

FIG. 14 is a graph showing a torque waveform (ninth embodiment).

FIG. 15 is a view showing a slit of a salient pole (tenth embodiment).

FIG. 16 is a view of a salient pole as viewed from a side (eleventh embodiment).

FIG. 17 is a view showing slits of salient poles (twelfth embodiment).

FIG. 18 is a graph showing a torque waveform (twelfth embodiment).

[Explanation of symbols]

 Reference Signs List 1 laminated plate of rotor 1a salient pole of rotor 2 laminated plate of stator 2a salient pole of stator 3 slit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiyuki Takabe 390 Umeda, Kosai-shi, Shizuoka Asso Co., Ltd. In-house (72) Inventor Naohisa Mimura 390 Umeda, Kosai-shi, Shizuoka Pref. Asmo Co., Ltd. In-house (72) Inventor Saito Tomohiro 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Inside Denso Corporation (72) Inventor Hideharu Yoshida 1-1-1, Showa-cho, Kariya-shi, Aichi prefecture Inside Denso Corporation

Claims (8)

[Claims] 1. A reluctance motor having a core formed by laminating a plurality of laminated plates made of a magnetic thin plate, wherein the laminated plate has a plurality of slits or grooves in salient poles thereof. A reluctance type electric motor, wherein the thickness is 5 times or less the maximum width of the slit or 5 times or less the maximum width of the groove. 2. The reluctance motor according to claim 1, wherein said slit is an open slit extending to an outer end of said salient pole. 3. The reluctance type electric motor according to claim 1, wherein within the same salient pole of the core, the position or number of slits or the slit width is different for each adjacent laminated plate. Reluctance type electric motor. 4. The reluctance type electric motor according to claim 1, wherein, within the same salient pole of the core, the position or the number of slits or the slit width is different for each of a plurality of adjacent laminated plates. Reluctance motor. 5. The reluctance motor according to claim 1, wherein the position or the number of slits or the width of the slit is different for each adjacent salient pole in one laminated plate. A reluctance motor having a plurality of salient poles having different numbers or different slit widths. 6. The reluctance type electric motor according to claim 1, wherein the laminated plates are overlapped by changing the front and back sides, or the laminated plates are overlapped with the positions of salient poles shifted. Alternatively, a reluctance type electric motor characterized in that the types of laminated plates are changed and the laminated plates are stacked. 7. The reluctance type electric motor according to claim 1, wherein the position or the number of the slits or the slit width is such that the front end in the rotation direction with respect to the opposing salient pole which is opposed at the time of rotation has a gap formed by the slit. A reluctance type electric motor characterized by being arranged to have a high density. 8. The reluctance type electric motor according to claim 1, wherein the position or the number of the slits or the width of the slit is such that the rear end in the rotation direction with respect to the opposite salient pole which is opposed during rotation is formed by the slit. A reluctance-type electric motor, wherein the electric motor is arranged so as to have a low air gap density.