JP4172093B2 - motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for improving a motor such as a switched reluctance motor (SR motor).
[0002]
[Prior art]
An SR motor is known as one of conventional motors. In the SR motor, a stator (stator) formed by integrally forming a plurality of inwardly projecting salient poles on a cylindrical yoke and a rotor (rotor) having a plurality of outwardly projecting salient poles are coaxial. Arranged above, windings (coils) are wound around the salient poles of the stator.
[0003]
The number of the salient poles of the rotor and the salient poles of the stator is set to an even number that is not in a multiple relationship with each other. For example, the number of salient poles of the rotor is 4, the number of salient poles of the stator is 6, the number of salient poles of the rotor is 6, the number of salient poles of the stator is 8, and the number of salient poles of the rotor is 8 On the other hand, the number of salient poles of the stator is 12.
[0004]
An electric current is passed through a pair of opposing windings (possibly further multiple windings) of the stator to generate a magnetic flux from the stator salient poles to the rotor salient poles, thereby attracting the rotor salient poles to the stator salient poles. Thus, torque is generated. At this time, if the salient poles of the stator and the rotor face each other, the other salient poles are misaligned, and if the salient poles that are sequentially deviated are selected and the windings are energized, the salient poles of the rotor will continuously It is attracted and the rotor can be rotated about its axis.
[0005]
[Problems to be solved by the invention]
However, most of the magnetic flux generated by energizing the windings passes through the salient poles of the stator 3 and the rotor 2 having a low magnetic resistance, as shown in FIG. In the vicinity of the end face of the rotor 2 in the axial direction, the salient pole of the stator 3 comes into the outside air from the end face in the axial direction of the stator 3 and then enters the salient pole of the rotor 2 from the end face in the axial direction of the salient pole of the rotor 2. The magnetic flux B entering the magnetic flux B and the magnetic flux B rotating around the winding 7 are generated without going to the salient pole of the rotor 2.
[0006]
Therefore, in the vicinity of the axial end surfaces of the rotor and the stator, a magnetic flux that pulls the rotor in the axial direction is generated, and a magnetic flux that does not generate torque that does not contribute to torque at all is generated. There was a problem of lowering the output. This phenomenon is particularly noticeable in SR motors that are used at a saturation magnetic flux density or higher. Especially in the case of a thin motor, the ratio of the magnetic flux that does not contribute to the magnetic flux that contributes to the generation of rotational torque increases. The decline is remarkable.
[0007]
The present invention has been made in view of such problems of the prior art, and an object thereof is to improve the output of a motor.
[0008]
[Means for Solving the Problems]
The present invention solves the above problems by the following means.
A motor according to a first aspect of the present invention includes a stator having a plurality of salient poles projecting inward, bobbins attached to the salient poles of the stator, and windings wound on the outer circumference in the circumferential direction with respect to the axial direction of the bobbin . In a motor provided with a wire and a rotor having a plurality of salient poles provided inside the stator and projecting outside ,
A nonmagnetic and conductive magnetic flux shielding member is provided on at least one end surface in the axial direction of the bobbin .
A motor according to a second aspect of the invention includes a stator having a plurality of salient poles projecting inward, a winding wound around each of the salient poles of the stator, and a plurality of projects provided inside the stator and projecting outward In a motor provided with a rotor having salient poles ,
A nonmagnetic and conductive magnetic flux shielding member having a diameter larger than the rotational diameter of the rotor is provided on at least one end surface in the axial direction of the rotor rotating about the axis .
A motor according to a third aspect of the present invention is a stator having a plurality of salient poles projecting inward, bobbins attached to the salient poles of the stator, and windings wound on the outer circumference in the circumferential direction with respect to the axial direction of the bobbin . In a motor provided with a wire and a rotor having a plurality of salient poles provided inside the stator and projecting outside ,
A nonmagnetic and conductive first magnetic flux shielding member is provided on at least one end surface in the axial direction of the bobbin, and a nonmagnetic and conductive first magnetic flux shielding member is provided on at least one end surface in the axial direction of the rotor rotating about the axis. Two magnetic flux shielding members are provided .
In the said invention, a magnetic flux shielding member may be comprised with a nonmagnetic electrically conductive film, and a nonmagnetic electrically conductive film can be formed by vapor deposition or plating.
In the said invention, a nonmagnetic electrically conductive film can be comprised with an aluminum vapor deposition film or a copper plating film.
In the above invention, the magnetic flux shielding member may be composed of a nonmagnetic conductive plate, and the nonmagnetic conductive plate may be composed of an aluminum plate.
In the above invention, the second magnetic flux blocking member, or approximately equal to the rotation diameter of the rotor may be constituted by a disc-shaped member that is set to a diameter larger Ri by it.
In the above invention, the first magnetic flux shielding member may be provided on both end faces in the axial direction of the bobbin , and the second magnetic flux shielding member may be provided on both end faces in the axial direction of the rotor .
[0009]
According to the invention , since the nonmagnetic and conductive magnetic flux shielding member is provided, when a part of the magnetic flux generated by energizing the winding enters the magnetic flux shielding member, an eddy current is generated in the magnetic flux shielding member. Since the eddy current flows in a direction that prevents the change of the magnetic flux, by appropriately setting the position where the magnetic flux shielding member is provided, the magnetic flux that does not contribute to the generation of torque effectively becomes the magnetic flux. It is possible to guide to a position where it is desired to be generated, and it is possible to contribute to generation of rotational torque that pulls the salient pole of the rotor in the direction around the axis.
[0011]
According to the above-described invention , the generation of magnetic flux that enters the outside of the salient pole of the rotor from the end face in the axial direction of the salient pole of the rotor after coming out into the outside air from the axial end face of the stator salient pole or the rotor Since the magnetic flux shielding member suppresses the generation of magnetic flux that goes around the winding without going to the salient pole, it is possible to increase the magnetic flux that contributes to the inherent generation of rotational torque.
[0012]
Further, by attaching the bobbin to the salient pole of the stator, the magnetic flux shielding member can be attached at the same time, so that the manufacturing is facilitated.
[0013]
Further, when the magnetic flux shielding member is composed of a nonmagnetic conductive film formed by vapor deposition or plating, such a film forming method is easy, and therefore the number of manufacturing steps for providing the magnetic flux shielding member can be reduced.
[0014]
Moreover, an eddy current can be effectively generated with low resistance by comprising a nonmagnetic electrically conductive film with an aluminum vapor deposition film or a copper plating film .
[0016]
By attaching a non-magnetic conductive plate as the magnetic flux shielding member on an end face in the axial direction of the rotor, for example, when the rotor is composed of laminated steel plates, such non-magnetic conductive plate fixing plate of the laminated steel sheet as the (end plates) The magnetic flux that contributes to the generation of the original rotational torque can be increased without complicating the configuration, and it is highly efficient.
[0018]
By making the diameter of the disk (non-magnetic conductive plate) substantially equal to the rotating diameter of the rotor, the end face portion of the rotor can be shielded, and the magnetic flux that effectively contributes to the generation of torque can be increased. In this case, since the nonmagnetic conductive plate is integrally attached to the rotor and can be assembled to the stator, the manufacturing operation is facilitated.
[0019]
In addition, by making the diameter of the disc (nonmagnetic conductive plate) larger than the rotating diameter of the rotor, not only the end surface portion of the rotor, but also the portion between the salient pole of the rotor and the salient pole of the stator, and further Since part of the pole can also be shielded, the magnetic flux that effectively contributes to the generation of torque can be further increased.
[0020]
In Rukoto be adopted an aluminum plate as a nonmagnetic conductive plate, while minimizing the increase in moment of inertia and weight, it can be generated effectively eddy current at a low resistance.
[0021]
【The invention's effect】
According to the invention, in Rukoto provided a non-magnetic, electrically conductive magnetic flux shielding member, it is possible to increase the effective magnetic flux contributing to the generation of torque. Therefore, the output torque of the motor can be increased by the increased magnetic flux. In addition, when making the output torque of a motor constant, a motor can be reduced in size.
[0022]
In addition , it is possible to suppress the generation of magnetic flux that enters the outside of the salient pole of the rotor after entering the outside air from the axial end face of the stator salient pole and then enters the rotor salient pole from the axial end face of the rotor. Thus, it is possible to more reliably prevent the generation of magnetic flux that goes around the winding without going to the rotor salient pole, and to increase the magnetic flux that effectively contributes to the generation of rotational torque.
[0023]
Further, in Rukoto provided on the end face in the axial direction of the bobbin for winding the winding flux shielding member eliminates the need for work for attaching the magnetic flux shielding member separately, is facilitated to manufacture, the manufacturing cost can be reduced it can.
[0024]
In addition, by a non-magnetic conductive film magnetic flux shielding member formed steam Chakumatawa plating, as compared with the case of providing a separately etc. plate-like body, with the magnetic flux shielding member can be stably provided, according bobbin Since it is relatively easy to form a film, the number of manufacturing steps can be reduced.
[0025]
Moreover , an eddy current can be generated effectively with a low resistance.
[0026]
Further, by attaching to the end face in the axial direction of the rotor flux shielding member as a plate-like body, for example, when the rotor is composed of laminated steel plates, such magnetic flux shielding member as a fixed plate of the laminated steel plate (end plate) The magnetic flux that effectively contributes to the generation of the rotational torque can be increased without complicating the configuration, for example, by making it function.
[0027]
In addition to increasing the magnetic flux that effectively contributes to torque generation by making the diameter of the non-magnetic conductive plate substantially equal to the rotational diameter of the rotor, the magnetic flux shielding member is integrally attached to the rotor. Thus, since it can be assembled to the stator, the manufacturing operation becomes easy.
[0028]
Further, by making the diameter of the nonmagnetic conductive plate larger than the rotating diameter of the rotor, not only the rotor end face part, but also the part between the rotor salient pole and the stator salient pole, and further part of the stator salient pole Can be shielded, so that the magnetic flux that effectively contributes to the generation of torque can be further increased.
[0029]
Further , an eddy current can be effectively generated with a low resistance while minimizing an increase in moment of inertia and weight.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0031]
First Embodiment FIG. 1 is a plan view showing a main part of a first embodiment of an SR motor (switched reluctance motor) according to the present invention, and FIG. 2 is an enlarged perspective view of the main part of FIG. FIG. 3A is a cross-sectional view taken along line III-III in FIG. The SR motor 1 of the first embodiment is a three-phase SR motor in which the number of stator salient poles is 6 and the number of rotor salient poles is 4.
[0032]
The SR motor 1 includes a rotor 2 as a rotor, a stator 3 as a stator, and a motor housing (not shown) that accommodates these.
[0033]
The rotor 2 is configured by inserting an output shaft (shaft) 5 into a through hole formed at the center of a rotor core 4 having a plurality of (four in this embodiment) salient poles 2a and fixing the output shaft integrally. The shaft 5 is supported by a motor housing via a bearing. In this embodiment, the rotor core 4 is configured by laminating and integrating a plurality of magnetic steel plates 4a punched by a press device.
[0034]
The stator 3 includes a stator core 6 and a plurality of winding coils 7. The stator core 6 is configured by integrally providing a plurality (six in this embodiment) of salient poles 3a protruding radially inward of a substantially cylindrical yoke portion. In this embodiment, the stator core 6 is configured by laminating and integrating a plurality of magnetic steel plates 6a punched by a press device. The stator 3 is fixed inside the motor housing.
[0035]
The rotor 2 is coaxially inserted and arranged so as to have a predetermined gap between the stator 3 and the salient pole 3 a of the stator 3. Winding coils 7 wound around bobbins 8 are mounted on the salient poles 3 a of the stator 3. The bobbin 8 is a member having a U-shaped cross section and is formed in a rectangular ring shape, and is formed of an insulating material such as a resin.
[0036]
Nonmagnetic conductive films (magnetic flux shielding members) 9a and 9b are formed on the outer surfaces of the pair of side walls of the bobbin 8 of this embodiment. The nonmagnetic conductive films 9a and 9b are formed by evaporating aluminum in this embodiment. However, copper plating or other nonmagnetic conductive materials may be formed by vapor deposition, plating, or other film forming methods.
[0037]
A winding coil 7 is wound around a portion between both side walls of the bobbin 8, and the salient pole 3a of the stator 3 is inserted into or inserted into a rectangular hole inside the bobbin 8, so that the salient pole 3a is fixed. Is done.
[0038]
By passing a current through a pair of winding coils 7 facing each other to generate a magnetic flux from the salient pole 3a of the stator 3 to the salient pole 2a of the rotor 2, and attracting the salient pole 2a of the rotor 2 existing in the vicinity thereof. , Generate torque. When the salient poles 2a, 3a of the stator 3 and the rotor 2 are opposed to each other, the other salient poles 2a, 3a are shifted from each other. The salient poles 2a of the rotor 2 are continuously attracted so that the rotor 2 can be rotated about its axis.
[0039]
When the winding coil 7 is energized, a magnetic flux B is generated from the salient pole 3a of the stator 3 toward the salient pole 2a of the rotor 2 as shown in FIG. To do. Since the nonmagnetic conductive films 9a and 9b are formed on the side wall of the bobbin 8, an eddy current I is generated in the films 9a and 9b in accordance with the change of the magnetic flux passing through the nonmagnetic conductive films 9a and 9b. Since the eddy current I flows in a direction that prevents the change of the magnetic flux, the presence of the nonmagnetic conductive films 9a and 9b causes the flow of the magnetic flux B to flow in the stator as indicated by arrows in FIG. 3 is less likely to deviate greatly from the end face of the salient pole 3a to the outside (upper side in the figure) and is guided to the salient pole 2a side of the rotor 2.
[0040]
As a result, the magnetic flux that effectively contributes to the generation of the rotational torque can be increased, and the output torque of the SR motor 1 can be improved. In particular, the increase in torque becomes significant in a high rotation range where the magnetic flux changes drastically.
[0041]
Here, for comparison, a case where the nonmagnetic conductive films 9a and 9b are not formed on the bobbin 8 is shown in FIG. In the absence of the nonmagnetic conductive films 9a and 9b, the salient poles of the rotor 2 come out into the outside air from the end faces of the salient poles 3a of the stator 3 in the vicinity of the axial end faces of the stator 3 and the rotor 2. The magnetic flux B that travels along the path entering from the end face of 2a and the magnetic flux B that turns from the outside of the winding coil 7 to the rear end without passing through the interior of the stator 3 are generated and rotated by that amount. Magnetic flux that does not contribute to the generation of torque was generated. On the other hand, in this 1st Embodiment, this point is improved and it understands that the magnetic flux which contributes to generation | occurrence | production of rotational torque can be increased.
[0042]
In the first embodiment described above, the nonmagnetic conductive films 9a and 9b are formed on the outer surfaces of both side walls of the bobbin 8, but the effect is somewhat reduced, but the nonmagnetic conductive film is formed only on one of the side walls. You may make it do. In addition, the nonmagnetic conductive film is not directly formed on the side wall of the bobbin 8, but a non-magnetic and conductive annular plate (a shape corresponding to the side wall of the bobbin) is bonded to the side wall of the bobbin 8. Even if it is fixed, the same effect can be obtained.
[0043]
Second Embodiment FIG. 4 is a plan view showing a main part of a second embodiment of an SR motor (switched reluctance motor) according to the present invention, and FIG. 5 is an enlarged perspective view of the main part of FIG. 6A is a cross-sectional view taken along the line VI-VI in FIG. Components that are substantially the same as those of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
[0044]
That is, in the second embodiment, the nonmagnetic conductive films 9 a and 9 b are not formed on the side wall of the bobbin 8, and the pair of nonmagnetic conductive plates 10 are integrally fixed to both end faces of the rotor core 4. As shown in these drawings, the nonmagnetic conductive plate 10 has a disk shape, and in the second embodiment, the nonmagnetic conductive plate 10 is formed of an aluminum plate. The diameter of the non-magnetic conductive plate 10 is set to a value larger than the rotational diameter of the rotor 2 so that a part thereof overlaps the tip of the salient pole 3 a of the stator 3.
[0045]
The rotor core 4 is composed of a laminated steel plate formed by laminating a plurality of magnetic steel plates 4a as in the first embodiment, but the nonmagnetic conductive plate 10 is used as a fixed plate (end plate) for these laminated steel plates 4a. Is also functioning. That is, by fixing the laminated steel plate 4a to the output shaft 5 while being sandwiched between the pair of nonmagnetic conductive plates 10, it is possible to prevent the laminated steel plate 4a from being damaged, i.e., being scattered. The gap between the end surface of the nonmagnetic conductive plate 10 facing the end surface of the salient pole 3a of the stator 3 (the end surface in the direction along the output shaft) and the end surface is in the thrust direction of the bearing that supports the output shaft 5. Considering the movable amount and the mounting accuracy, it should be set as narrow as possible within the range where they do not contact each other.
[0046]
When the SR motor 1 is assembled, the nonmagnetic conductive plate 10 is larger than the rotation diameter of the rotor 2, so that the laminated steel plate 4 a is sandwiched between the pair of nonmagnetic conductive plates 10 and then disposed inside the stator 3. In this case, one of the nonmagnetic conductive plates 10 is removed, and the rotor 2 is inserted and arranged inside the stator 3 and then the other is fixed.
[0047]
When the winding coil 7 is energized, a magnetic flux is generated from the salient pole 3a of the stator 3 toward the salient pole 2a of the rotor 2, but since the nonmagnetic conductive plate 10 is attached to the rotor 2, this nonmagnetic conductive plate As shown in FIG. 5, an eddy current I is generated in the nonmagnetic conductive plate 10 as the magnetic flux passing through 10 is changed, and this eddy current I flows in a direction that prevents the magnetic flux from changing. The presence of the nonmagnetic conductive plate 10 causes the flow of the magnetic flux B from the end face of the salient pole 3a of the stator 3 to the outside (upper side in the figure), as indicated by an arrow in FIG. Is almost guided to the salient pole 2a side of the rotor 2.
[0048]
As a result, the magnetic flux that effectively contributes to the generation of the rotational torque can be increased, and the output torque of the SR motor 1 can be improved. In particular, the increase in torque becomes significant in a high rotation range where the magnetic flux changes drastically.
[0049]
Here, for comparison, the case where the nonmagnetic conductive plate 10 is not attached to the rotor 2 is shown in FIG. In the absence of this nonmagnetic conductive plate 10, in the vicinity of the axial end faces of the stator 3 and the rotor 2, the salient poles 2 a of the rotor 2 are exposed to the outside air from the end faces of the salient poles 3 a of the stator 3. A magnetic flux B traveling along a path entering from the end face is generated, and a magnetic flux that does not contribute to the generation of rotational torque is generated. On the other hand, in the second embodiment, the magnetic flux B is returned to the salient pole 2a side of the rotor 2 by the nonmagnetic conductive plate 10, so that it is understood that the magnetic flux contributing to the generation of rotational torque can be increased. The
[0050]
In the second embodiment described above, the nonmagnetic conductive plates 10 are attached to both ends of the rotor core 4, respectively, but the effect is somewhat reduced, but the nonmagnetic conductive plates 10 may be attached to only one of them. In addition, the diameter of the nonmagnetic conductive plate 10 is set to be larger than the rotation diameter of the rotor 2 so that a part thereof overlaps the salient pole 3 a of the stator 3. The diameter may be such that it does not reach the pole 3a, or may be set to a diameter that is substantially the same as the rotational diameter of the rotor 2.
[0051]
The nonmagnetic conductive plate is not limited to a circular plate, and can be a plate-like body having the same shape as the laminated steel plate 4a constituting the rotor core 4, for example. In addition, in the second embodiment, the nonmagnetic conductive plate is integrally attached to the rotor 2, but may be attached to the tip of the salient pole 3 a of the stator 3 so as not to contact the rotor 2.
[0052]
In the second embodiment described above, the nonmagnetic conductive films 9a and 9b are not formed on the side wall of the bobbin 8. However, in the configuration of the second embodiment, the side wall of the bobbin 8 is the same as in the first embodiment. If the nonmagnetic conductive films 9a and 9b are formed, the magnetic flux that effectively contributes to the rotational torque can be further increased by the interaction between the nonmagnetic conductive films 9a and 9b and the nonmagnetic conductive plate 10.
[0053]
Furthermore, in the second embodiment described above, the winding coil 7 is wound around the bobbin 8, but the winding coil wound without using the bobbin is attached to the salient pole 3a of the stator 3, or the salient Even if it is the structure which winds a coil wire directly on the pole 3a and makes it a winding coil, it can apply similarly.
[0054]
The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0055]
For example, in the first and second embodiments described above, the application of the present invention to the SR motor is described, and this is because it is particularly preferable to apply to the SR motor used at a saturation magnetic flux density or higher. Of course, other types of motors can be applied. Further, the number of salient poles and the number of phases of the stator and the rotor are not limited to those in the first and second embodiments described above, and other types can be similarly applied.
[Brief description of the drawings]
FIG. 1 is a plan view showing a main part of a first embodiment of an SR motor according to the present invention.
FIG. 2 is an enlarged perspective view of a main part of FIG.
3 is a cross-sectional view (a) taken along line III-III in FIG. 1 and a cross-sectional view (b) showing the configuration of the prior art corresponding thereto.
FIG. 4 is a plan view showing a main part of a second embodiment of the SR motor according to the present invention.
5 is an enlarged perspective view of a main part of FIG.
6 is a cross-sectional view (a) taken along the line VI-VI in FIG. 4 and a cross-sectional view (b) showing the configuration of the prior art corresponding thereto.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... SR motor 2 ... Rotor 2a ... Salient pole 3 ... Stator 3a ... Salient pole 4 ... Rotor core 5 ... Output shaft 6 ... Stator core 7 ... Winding coil 8 ... Bobbin 9a, 9b ... Nonmagnetic conductive film 10 ... Nonmagnetic conductive plate B ... Magnetic flux I ... Eddy current

Claims (8)

A stator having a plurality of salient poles projecting inward;
A bobbin mounted on each of the salient poles of the stator ;
A winding wound around the outer circumference in the circumferential direction with respect to the axial direction of the bobbin ;
In a motor provided with a rotor having a plurality of salient poles provided inside the stator and projecting outside ,
A motor having a nonmagnetic and conductive magnetic flux shielding member provided on at least one end surface of the bobbin in the axial direction . The motor according to claim 1,
The magnetic flux shielding member is made of a nonmagnetic conductive film,
  The motor, wherein the nonmagnetic conductive film is formed by vapor deposition or plating. The motor according to claim 2,
The motor , wherein the nonmagnetic conductive film is an aluminum vapor deposition film or a copper plating film. A stator having a plurality of salient poles projecting inward;
Windings wound around each of the salient poles of the stator;
In a motor provided with a rotor having a plurality of salient poles provided inside the stator and projecting outside ,
A nonmagnetic and conductive magnetic flux shielding member having a diameter larger than the rotational diameter of the rotor is provided on at least one end surface in the axial direction of the rotor rotating about an axis. . The motor according to claim 4,
The magnetic flux shielding member is composed of a nonmagnetic conductive plate,
The motor according to claim 1, wherein the nonmagnetic conductive plate is an aluminum plate. A stator having a plurality of salient poles projecting inward;
A bobbin mounted on each of the salient poles of the stator ;
A winding wound around the outer circumference in the circumferential direction with respect to the axial direction of the bobbin ;
In a motor provided with a rotor having a plurality of salient poles provided inside the stator and projecting outside ,
A nonmagnetic and conductive first magnetic flux shielding member is provided on at least one end surface of the bobbin in the axial direction ,
A nonmagnetic and conductive second magnetic flux shielding member is provided on at least one end surface of the rotor rotating around an axis in the axial direction . The motor according to claim 6,
It said second magnetic flux shielding member, a motor, wherein the or substantially equal to the rotation diameter of the rotor is a disc-shaped member that is set to a diameter larger Ri by it. The motor according to claim 6 or 7, wherein
The first magnetic flux shielding member is provided on both axial end surfaces of the bobbin ,
The motor, wherein the second magnetic flux shielding member is provided on both end surfaces of the rotor in the axial direction .

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