JP2010263718A - Axial gap motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial gap motor improved in the magnetic pole structure of a stator and made thinner and lighter than a conventional motor. <P>SOLUTION: Stator magnetic poles 41, 42 which are excited by the energization of a concentrated winding excitation coil 6 are circumferentially arranged with the same number of poles at the internal peripheral side and the external peripheral side of a magnetic pole face opposing a rotor 2 of the stator 3, the stator magnetic pole 41 at the internal peripheral side of the stator 3 is excited to one polarity, and the stator magnetic pole 42 at the external peripheral side of the stator 3 is excited to the other polarity reverse to the one polarity. By this arrangement, the magnetic flux of the stator 3 is dispersed in the circumferential direction and the radial direction of a yoke, and the thickness in the axial direction of the stator 3 can be thinned more than that of the conventional motor. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an axial gap motor in which a rotor and a stator are arranged opposite to each other on a motor shaft, and more particularly to reduction in thickness and weight.

  In recent years, axial gap motors have attracted attention as one of drive motors for electric vehicles and hybrid cars.

  In general, an axial gap motor is formed by arranging a rotor magnetic pole and a stator magnetic pole in a circumferential direction (a direction in which the motor shaft rotates) on a magnetic pole surface (a surface orthogonal to the motor shaft) facing the rotor and the stator. The rotor magnetic pole is formed by a magnetic salient pole (pole) or permanent magnet, and the stator magnetic pole is formed by concentrically winding coils of each phase around the magnetic salient pole (tooth).

  12 (a) and 12 (b) are front views in which the coils on the opposing surfaces of the rotor 100 and the stator 200 of the conventional axial gap motor are removed, and the coils of each phase are removed from the stator 200. FIG. Eight rotor magnetic poles 102 are disposed on the disk-shaped back yoke 101 of the rotor 100, and 12 stator magnetic poles 202 are disposed on the disk-shaped back yoke 201 of the stator 200.

  In the case of three-phase driving, the stator magnetic poles 202 are energized in the order of the phases by energizing the stator magnetic poles 202 with the U, V, and W exciting coils in a concentrated manner. Moving. Further, the stator magnetic pole 202 of the excitation phase is excited alternately to the N pole and the S pole in the circumferential direction. The rotor 100 rotates and the motor shaft (not shown) rotates due to the magnetic action of the stator magnetic pole 202 and the rotor magnetic pole 102 (see, for example, Patent Documents 1 and 2).

JP 2005-151725 A JP 2008-245363 A

  The conventional axial gap motor has a configuration in which stator magnetic poles 202 are arranged in a row (single) in the circumferential direction on the yoke surface of the stator 200, as shown in FIG. The magnetic path of the back yoke 201 branches from the magnetic pole 202 to the left and right and moves around to reach the N-pole stator magnetic pole 202 of the left and right excitation phases.

  FIG. 13 shows the magnetic flux of the U-phase excitation stator 200. When the magnetic flux of the U-phase S-pole stator magnetic pole 202 is indicated by four magnetic flux lines φa indicated by broken arrows, each of the four magnetic flux lines φa is two. Branching to about 1/4 turn of the magnetic path of the back yoke 201 to the left and right to reach the U-phase N-pole stator pole 202 on both the left and right sides. At this time, the N-pole stator magnetic pole 202 receives two magnetic flux lines φa from the left and right adjacent S-pole stator magnetic poles 202 and outputs a total of four magnetic flux lines φa. Therefore, the two magnetic flux lines φa pass through the magnetic path of the back yoke 201, and the axial thickness of the back yoke 201 needs to be increased so as to correspond to the magnetic flux density of the two magnetic flux lines φa. The axial gap motor is thick in the axial direction and has a large mass, and there is a problem that the axial gap motor cannot be sufficiently reduced in thickness and weight.

  An object of the present invention is to provide an axial gap motor that is thinner and lighter than the conventional one by improving the magnetic pole structure of the stator so that the stator back yoke can be made thinner than the conventional one.

  In order to achieve the above object, an axial gap motor of the present invention is an axial gap motor in which a stator and a rotor are opposed to each other, and the stator is disposed on an inner peripheral side and an outer peripheral side of a magnetic pole surface facing the rotor. The same number of stator magnetic poles excited by energization of the concentrated winding coil are arranged in the circumferential direction, the stator magnetic pole on the inner peripheral side of the stator is excited to one polarity, and the stator magnetic pole on the outer peripheral side of the stator is the one polarity It is characterized in that it is excited to the other polarity opposite to (Claim 1).

  In the axial gap motor of the present invention, the stator magnetic pole on the inner peripheral side of the stator and the stator magnetic pole on the outer peripheral side are preferably displaced in the circumferential direction.

  In the axial gap motor of the present invention, the stator magnetic pole on the inner peripheral side of the stator and the stator magnetic pole on the outer peripheral side have a vertically elongated magnetic pole surface on the inner peripheral side, and the magnetic pole surface of the stator magnetic pole on the outer peripheral side A horizontally long shape is preferred (claim 3).

  Furthermore, it is preferable that the stator of the axial gap motor of the present invention includes a loop-shaped field coil disposed between the stator pole on the inner peripheral side and the stator magnetic pole on the outer peripheral side.

  Further, in the rotor of the axial gap motor of the present invention, an inner circumferential rotor magnetic pole and an outer circumferential rotor magnetic pole are arranged in a circumferential direction on a magnetic pole surface facing the stator, and the field coil is arranged on the inner circumferential side. It is more desirable that the stator magnetic pole and the stator magnetic pole on the outer peripheral side protrude in the direction of the rotor and be inserted in a non-contact state into a recess formed by a gap between the rotor magnetic pole on the inner peripheral side of the rotor and the rotor magnetic pole on the outer peripheral side. (Claim 5).

  In the case of the axial gap motor of the present invention according to claim 1, the magnetic poles of the stator are composed of inner and outer stator poles arranged concentrically in the circumferential direction on the magnetic pole surface facing the rotor, The magnetic flux is dispersed in the circumferential direction and the radial direction of the back yoke disposed on the side opposite to the magnetic pole surface of the stator magnetic pole. Since the number of magnetic poles of the stator is doubled and the magnetic path between the magnetic poles of the stator is shortened as compared with the conventional motor in which the stator magnetic poles are arranged in a row (single), the stator magnetic poles on the inner and outer peripheral sides The magnetic flux entering and exiting each of them decreases to ½ of the magnetic flux entering and exiting each stator magnetic pole of the conventional motor, and the density of the magnetic flux passing through the magnetic path of the back yoke between the stator magnetic poles also decreases to approximately ½.

  Therefore, the axial thickness of the back yoke of the stator can be reduced to ½ that of the conventional motor, and the axial thickness of the stator can be made thinner than that of the conventional motor. As a result, the axial gap motor can be formed thinner in the axial direction than in the prior art, and an unprecedented thin and lightweight axial gap motor can be provided. In addition, since the stator magnetic poles on the inner and outer peripheral sides correspond to the magnetic poles obtained by dividing the stator magnetic pole of the conventional motor into two parts, the stator does not increase in the radial direction, and even if the number of magnetic poles of the stator is doubled, the axial gap motor Does not increase in size in the radial direction.

  In the case of the axial gap motor according to the second aspect of the present invention, the stator magnetic pole on the inner peripheral side of the stator and the stator magnetic pole on the outer peripheral side are arranged with their positions shifted in the circumferential direction. And leakage inductance does not increase. Therefore, there is an advantage that the output at high rotation can be improved. In addition, since the magnetic poles are more dispersedly arranged, local magnetic saturation is less likely to occur in the back yoke, so that a thinner and lighter axial gap motor can be provided by making the back yoke of the stator thinner. it can.

  In the case of the axial gap motor of the present invention according to claim 3, the stator magnetic pole on the inner peripheral side of the stator whose circumferential width is shortened has a vertically elongated magnetic pole surface, and the stator magnetic pole on the outer peripheral side of the stator whose circumferential width becomes longer. Since the stator magnetic pole has a horizontally long magnetic pole surface, it is possible to make the magnetic pole surfaces of the outer peripheral stator magnetic pole and the inner peripheral stator magnetic pole as large as possible by using the stator space without waste.

  In the case of the axial gap motor of the present invention according to claim 4, the field coil applies a bias magnetic field in the direction of increasing the magnetic flux to the stator magnetic pole on the inner peripheral side and the stator magnetic pole on the outer peripheral side, and outputs (torque). Can be bigger.

  In the case of the axial gap motor of the present invention according to claim 5, by providing the field coil so as to protrude from the inner and outer stator poles toward the rotor, the inner and outer stator poles are provided. The magnetic pole area is not reduced. In addition, since the field coil is inserted into the concave portion between the rotor magnetic poles on the inner peripheral side and the outer peripheral side of the rotor, an increase in axial thickness due to the field coil is prevented. Therefore, it is possible to provide an innovative axial gap motor that is thin, lightweight, and has high output.

1 is a side view of an axial gap motor according to a first embodiment of the present invention. (A), (b) is a perspective view of the rotor and stator of the axial gap motor of FIG. (A), (b) is a front view of the magnetic pole surface of the rotor of FIG. 2, and a stator. It is explanatory drawing of the arrangement | sequence of each phase of the stator of FIG. It is explanatory drawing of the magnetic path of the stator of FIG. (A), (b) is the front view of the magnetic pole surface of the stator of the 2nd Embodiment of this invention, and a side view explaining thickness. (A), (b) is the front view of the magnetic pole surface of the rotor of the 2nd Embodiment of this invention, and a side view explaining thickness. It is a side view of the axial gap motor of the 3rd Embodiment of this invention. It is a side view of the axial gap motor of the 4th Embodiment of this invention. (A), (b) is a perspective view of the rotor and stator of the axial gap motor of FIG. (A), (b) is the characteristic figure of the magnetic flux at the time of adding a field coil in the case of only the exciting coil of the axial gap motor of FIG. (A), (b) is a front view of the magnetic pole surface of the rotor of a conventional axial gap motor, and a stator. It is explanatory drawing of the magnetic path of the stator of FIG.

  Next, in order to describe the present invention in more detail, an embodiment will be described with reference to FIGS.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a side view of the three-phase drive axial gap motor 1A according to the present embodiment as viewed from a direction orthogonal to the axial direction. A dashed line in the figure indicates a motor shaft. A rotatable rotor 2 having a central portion pivotally attached to the motor shaft and a fixed stator 3 having the motor shaft penetrating the central portion are arranged opposite to each other in the axial direction. The rotor 2 and the stator 3 include disk-shaped back yokes 21 and 31 having substantially the same size as a magnetic body formed of, for example, a dust core and laminated steel plates.

  2 (a), 2 (b), 3 (a), and 3 (b) show the shape and structure of the magnetic poles of the rotor 2 and the stator 3. First, the stator 3 having a configuration of 24 magnetic poles (three-phase eight magnetic poles) is shown. Twelve stator magnetic poles 41 and 42 formed by magnetic salient poles are arranged at equal intervals in the circumferential direction on the inner peripheral side and the outer peripheral side of the yoke surface facing the rotor 2 of the back yoke 31. At that time, the magnetic pole surface of the stator magnetic poles 41 and 42 has the same shape as the magnetic pole surfaces of the stator magnetic poles 41 and 42 to make the magnetic pole surfaces of the stator magnetic poles 41 and 42 as equal as possible to keep the magnetic characteristics constant. It is formed as follows. That is, each stator pole 41 on the inner circumferential side whose width in the circumferential direction becomes shorter is a wedge shape (or a triangle) whose pole surface tapers in the axial direction and has a vertically long shape, and on the outer circumferential side whose width in the circumferential direction becomes longer. Each of the stator magnetic poles 42 has a horizontally long rectangular magnetic pole surface and a horizontally long shape.

  The inner and outer stator poles 41 and 42 are, for example, the inner stator pole 41 excited to the S pole (one polarity) and the outer stator pole 42 the N pole (the other pole). The polarity is excited.

  Next, the rotor 2 only needs to have a configuration with an appropriate number of magnetic poles different from that of the stator 3 in order to rotate, and generally has a smaller number of magnetic poles than the stator 3. Specifically, the rotor 2 is preferably 10 or 8 magnetic poles with respect to the 12 magnetic pole stator 3.

  When the rotor 2 has a 10 magnetic pole configuration, if the stator 3 does not include a field coil to be described later, like the rotor 100 of the conventional motor in FIG. 12A, the stator 3 of the back yoke 21 of the rotor 2. Ten rotor magnetic poles may be arranged in a row (single) in the circumferential direction on the yoke surface facing the stator, but in this embodiment, the stator magnetic pole 41 on the inner peripheral side of the stator 3 and the stator magnetic pole 42 on the outer peripheral side. 10 rotor magnetic poles 51 and 52 formed by magnetic salient poles or magnet bodies are concentrically arranged on the inner peripheral side and the outer peripheral side of the yoke surface facing the stator 3 of the back yoke 21, respectively. They are formed at regular intervals in the circumferential direction. At this time, the magnetic pole surfaces of the rotor magnetic poles 51 and 52 are made to be as equal as possible to the magnetic pole surfaces of the stator magnetic poles 41 and 42. Therefore, the rotor magnetic pole 51 on the inner peripheral side has the same vertical shape as the stator magnetic pole 41 on the inner peripheral side. This rotor magnetic pole 52 has the same horizontally long shape as the outer peripheral stator magnetic pole 42.

  Next, the arrangement and excitation of the stator magnetic poles 41 and 42 in the stator 3 will be described.

  FIG. 4 shows a state in which the exciting coil 6 is mounted on the stator magnetic poles 41 and 42 of the stator 3. The stator magnetic poles 41 and 42 respectively form U, V, and W magnetic poles in the circumferential direction. The stator magnetic poles 41 and the stator magnetic poles 42 on the outer circumferential side are arranged with their positions shifted in the circumferential direction by about ½ of the magnetic pole interval (center distance) La of the stator magnetic poles 42. More specifically, the inner peripheral stator magnetic pole 41 is disposed at a position shifted by a distance Lb (= (3/2) · La) from the outer peripheral stator magnetic pole 42 forming the magnetic pole pair. If the positions of the stator magnetic pole 41 on the inner peripheral side and the stator magnetic pole 42 on the outer peripheral side are shifted, the stator magnetic poles 41 and 42 can be more effectively distributed in the circumferential direction and the radial direction.

  Further, the inner peripheral side stator magnetic pole 41 and the outer peripheral side stator magnetic pole 41 forming the magnetic pole pair are excited so that the inner peripheral side stator magnetic pole 41 is excited to the S pole and the outer peripheral side stator magnetic pole 42 is excited to the N pole. In addition, the exciting coil 6 is concentratedly wound in opposite directions.

  Then, by sequentially switching the excitation phase to U, V, W, for example, when the U phase becomes the excitation phase, the four U-phase stator magnetic poles 41 on the inner peripheral side are excited to the S pole, and these stator magnetic poles Four U-phase stator magnetic poles 42 on the outer peripheral side at positions shifted in the circumferential direction from 41 are excited to N poles. At this time, the magnetic flux of the N-pole stator pole 42 enters the S-pole stator pole 41 through the rotor poles 51 and 52 of the rotor 2, and reaches the stator pole 42 from the stator pole 41 through the magnetic path of the back yoke 31. . During this time, the rotor 2 rotates by a magnetic action. Thereafter, when the excitation phase is switched to V, W, U,..., The rotor 2 continues to rotate in the same manner.

  In the axial gap motor 1A having the above-described configuration, the magnetic poles of the stator 3 are the inner and outer stator poles that are concentrically arranged in the circumferential direction on the yoke surface facing the rotor 2 of the back yoke 31. 41, 42. The stator magnetic poles 41 and 42 are respectively the number (12) of the stator magnetic poles 202 of the conventional motor, and the inner peripheral stator magnetic pole 41 and the corresponding outer peripheral stator magnetic pole 42 are positioned in the circumferential direction. Are arranged. Therefore, the magnetic poles of the stator 3 are in a state where the stator magnetic poles 202 of the conventional motor are very effectively dispersed in the circumferential direction and radial direction of the yoke surface.

  In this case, as compared with the conventional motor in which the stator magnetic poles 202 are arranged in a single row (single), the axial gap motor 1A has the number of magnetic poles of the stator 3 doubled and the magnetic flux is dispersed on the yoke surface. The magnetic flux passing through 42 is reduced to ½ of the magnetic flux passing through the stator pole 202 of the conventional motor. On the other hand, the number of excitation switching required for one rotation is 12 times that of the conventional motor, and the drive frequency does not increase.

  FIG. 5 shows the magnetic flux of the U-phase excited stator 3 and corresponds to FIG. The number (8) of U-phase stator magnetic poles 41, 42 of the axial gap motor 1A is twice the number (4) of U-phase stator magnetic poles 202 of the conventional motor shown in FIG. The magnetic flux line φb indicated by the broken line arrow in FIG. 5 entering the phase S stator pole 41 is two of the magnetic flux lines φa indicated by the broken line arrow in FIG. Then, the two magnetic flux lines φb of the S-pole stator magnetic pole 41 are branched one by one, and the magnetic path of the back yoke 31 connecting the stator magnetic poles 41 and 42 is moved about 1/8 to the left and right. To the U-phase N-pole stator pole 42. At this time, the N-pole stator magnetic pole 42 receives one magnetic flux line φb from each of the left and right adjacent S-pole stator magnetic poles 41, and outputs the magnetic flux of two magnetic flux lines φb in total.

  As is clear from a comparison between the magnetic flux line φa in FIG. 12 and the magnetic flux line φb in FIG. 5, in the case of the conventional motor, the magnetic flux in the magnetic path of the back yoke 201 that connects the S pole and the N pole stator pole 202. Whereas the amount is represented by two magnetic flux lines φb, in the case of the axial gap motor 1A, the amount of magnetic flux in the magnetic path of the back yoke 31 that connects the S and N pole stator poles 41 and 42 is one. The magnetic flux line φb is reduced to 1/2 that of the conventional motor.

  Therefore, the back yoke 31 of the stator 3 has the same magnetic flux density as that of the back yoke 201 of the conventional motor even if the axial thickness is reduced to ½ of the thickness of the back yoke 201 of the stator 200 of the conventional motor. Then, by reducing the axial thickness of the back yoke 31 to ½ of the thickness of the back yoke 201, the axial thickness of the axial gap motor 1A can be made thinner than that of the conventional motor. A lightweight axial gap motor 1A can be provided. Since the stator magnetic poles 41 and 42 on the inner peripheral side and the outer peripheral side correspond to magnetic poles obtained by dividing the stator magnetic pole 202 of the conventional motor into two parts, the stator 3 does not have to be enlarged in the radial direction, and the number of magnetic poles of the stator 3 is 2. Even if it is doubled, the axial gap motor 1A does not increase in size in the radial direction.

  By the way, even if one magnetic pole of the stator pole 41 on the inner peripheral side is an N pole and the other magnetic pole of the stator magnetic pole 42 on the outer peripheral side is an S pole, the same is true.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS. In these drawings, the same reference numerals as those in FIGS. 1 to 5 denote the same or corresponding components.

  In the axial gap motor 1A, the thickness of the back yoke 31 of the stator 3 can be reduced, and the number of rotor magnetic poles 51 and 52 is doubled in the back yoke 21 of the rotor 2 as well. By reducing both the thicknesses of the back yokes 21 and 31, the axial gap motor 1A that is thinner and lighter can be provided.

  Since the amount of magnetic flux in the stator 3 of the rotor 2 decreases as it reaches the ends of the inner and outer magnetic bodies, the back gap 21 of the rotor 2 and the stator are reduced in order to reduce the axial gap motor 1A as much as possible. The thickness of the back yoke 31 in the axial direction is preferably increased in the middle portion and thinner toward the outer periphery and the inner periphery. As a method for this, a continuous inclination is applied to the back side of the back yokes 21 and 31. It may be attached, and a step may be provided on the back side of the back yokes 21 and 31.

  6 (a) and 6 (b) show the configuration of the stator 3 of this embodiment, and FIG. 6 (b) shows the stator 3 cut in the thickness direction (motor shaft direction) as indicated by the broken line in FIG. 6 (a). It is sectional drawing. As apparent from FIG. 6, the stator 3 of the present embodiment has an annular portion α1 on the outer peripheral edge of the back yoke 31 and an annular portion α2 on the inner peripheral edge of an intermediate portion α3 between the annular portions α1 and α2. It is formed in a stepped portion having a thickness de that is about ½ of the thickness dc. The annular part α1 is a part of the outer peripheral edge from the radial center of the stator pole 42 on the outer peripheral side, and the annular part α2 is a part of the inner peripheral edge closer to the motor shaft than half of the stator magnetic pole 41 on the inner peripheral side in the radial direction. It is. Further, more than half of the stator magnetic poles 41 and 42 including the central portion overlap with the intermediate portion α3 of the back yoke 31, and the back yoke 31 is provided with a step so as to be as thin and light as possible while ensuring sufficient strength. Has been processed. Since the stator 3 does not rotate, there is no problem even if the thickness of the end portion of the central opening through which the motor shaft passes is not increased in the annular portion α2 on the inner peripheral side.

  Further, the stator 3 of the present embodiment forms a concave stepped portion 7 over the entire circumference on the backside of the outer peripheral edge and the inner peripheral annular portions α1 and α2 of the back yoke 31 and each stepped portion 7 is energized. A bus ring 8 for connecting the coil 6 is inserted. Then, the coil terminal is drawn out from an appropriate portion of the extension range of the stator magnetic poles 41 and 42 of the annular portions α1 and α2 and connected to the bus ring 8. By doing so, the bus ring 8 for coil connection is disposed in the portion where the thickness of the stator 3 is reduced, and the axial gap motor 1A can be further reduced in size by eliminating the protrusion of the coil end.

  FIGS. 7A and 7B show the configuration of the rotor 2 of the present embodiment, and FIG. 7B shows the rotor 2 cut in the thickness direction (motor shaft direction) at the position indicated by the broken line in FIG. It is sectional drawing. As apparent from FIG. 7, the rotor 2 of this embodiment is thinly processed with an inclination so that the back surface of the back yoke 21 on the outer peripheral side and the inner peripheral side is gradually thinner. The central opening edge attached to the motor shaft on the inner peripheral side is thickened to ensure strength.

  Therefore, in the case of the present embodiment, by reducing the thickness of the back yokes 21 and 31 of the rotor 2 and the stator 3, it is possible to provide a thinner and lighter axial gap motor. In addition, since the bus ring 8 is fitted into the annular recess member 7 provided at the back step of the back yoke 31 of the stator 3, the axial gap motor 1A can be further reduced in size.

  Note that the thickness of the back yoke 31 of the stator 3 may be made thinner by being inclined like the back yoke 21 of the rotor 2, and the thickness of the back yoke 21 of the rotor 2 may be reduced as the back yoke 31 of the stator 3. You may make it thin by providing a level | step difference. Of course, both of the back yokes 21 and 31 may be thinned by processing them in the same way to form an inclination or provide a step.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG. In FIG. 8, the same reference numerals as those in FIGS. 1 to 7 denote the same or corresponding components.

  FIG. 8 is a side view of the assembled state of the axial gap motor 1B of the present embodiment. The axial gap motor 1B is similar to the axial gap motor 1A of the second embodiment, and the back yokes 21 and 31 of the rotor 2 and the stator 3 are illustrated. The thickness of is processed thin. Further, in the axial gap motor 1B, the magnetic pole surfaces of the rotor magnetic poles 51 and 52 of the rotor 2 and the stator magnetic poles 41 and 42 of the stator 3 are processed into an uneven surface 10 that is concentric with the motor shaft.

  Therefore, in the axial gap motor 1B, the magnetic pole surface areas of the rotor 2 and the stator 3 are expanded as much as possible to increase the torque (output), and are thin and light, and also have high output.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. 9, FIG. 10, and FIG.

  9 and 10, the same reference numerals as those in FIGS. 1 to 8 denote the same or corresponding elements. As shown in these drawings, the axial gap motor 1 </ b> C of the present embodiment is roughly the second embodiment. The rotor 2 and the stator 3 are thinned, and the loop-shaped field coil 11 of the present invention is provided between the stator magnetic pole 41 on the inner peripheral side of the stator 3 and the stator magnetic pole 42 on the outer peripheral side. . The loop shape includes not only a circle and an ellipse but also a polygon.

  The field coil 11 is formed of an enameled coated wire similar to that of the exciting coil 6. In this embodiment, the field coil 11 is fixedly mounted on the surface of the stator magnetic poles 41 and 42 by bonding or using an appropriate support member. And protrudes in the direction of the rotor 2. Further, the field coil 11 projecting in the direction of the rotor 2 is arranged so that the rotor 2 and the stator 3 face each other so that the gap between the rotor magnetic pole 51 on the inner peripheral side of the rotor 2 and the rotor magnetic pole 52 on the outer peripheral side is reduced. A part or the whole is inserted and accommodated in the annular recess 12 having a sufficiently wide width so as not to contact the rotor magnetic poles 51 and 52.

  The field coil 11 generates a predetermined bias magnetic flux in a direction in which the outer peripheral side of the stator 3 is an N pole and the inner peripheral side is an S pole in accordance with the magnetic polarities of the stator magnetic poles 41 and 42. The bias magnetic flux is superimposed and added to the magnetic flux of the excitation coil 6 of the stator magnetic poles 41 and 42 in the excitation phase, thereby increasing the magnetic flux of the stator magnetic poles 41 and 42 in the excitation phase.

  FIG. 11A shows the current characteristics of the magnetic flux generated only by the exciting coil 6, and FIG. 11B shows the current characteristics of the magnetic flux when the bias magnetic flux is superimposed and added to the magnetic flux of the exciting coil 6. The characteristic shown in FIG. 11B is a characteristic obtained by shifting the characteristic shown in FIG. 11A to the left. As is clear from the comparison of the hatched portions in both figures, the excitation phase is changed by the superimposed addition of the bias magnetic flux. It can be seen that the magnetic flux energy of the stator magnetic poles 41 and 42 increases and the magnetic field energy increases. As a result, the generated torque of the axial gap motor 1C increases and the output increases accordingly.

  Therefore, in the case of the present embodiment, the axial length (physique) of the axial gap motor 1C is not increased, the increase in the axial thickness due to the field coil 11 is prevented, and it is a thin, lightweight and high output epoch. A typical axial gap motor 1C can be provided.

  The present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from the spirit thereof. For example, the number of magnetic poles of the stator 3 is 24. Similarly, the number of magnetic poles of the rotor 2 is not limited to 16 poles. Further, similarly to the rotor magnetic pole 102 of the conventional motor, the rotor 2 may be provided with, for example, 10 rotor magnetic poles in a row (single) in the circumferential direction.

  Next, the inner peripheral stator magnetic pole 41 and the rotor magnetic pole 51 may not have a vertically elongated magnetic pole surface. Similarly, the outer peripheral stator magnetic pole 42 and the rotor magnetic pole 52 may not have a horizontally elongated magnetic pole surface. . For example, the magnetic pole surfaces of the inner peripheral stator magnetic pole 41, the rotor magnetic pole 51, and the outer peripheral stator magnetic pole 42, the rotor magnetic pole 52 have the same shape, such as a circular shape, a polygonal shape, a rectangular shape, etc., having substantially the same area. Also good.

  The present invention can be applied not only to axial gap motors used as drive motors for electric vehicles and hybrid cars, but also to axial gap motors for various applications. In this case, the axial gap motor may be a multiphase drive motor having four or more phases.

1A, 1B, 1C Axial gap motor 2 Rotor 3 Stator 6 Excitation coil 11 Field coil 12 Recess 21, 31 Back yoke 41, 42 Stator magnetic pole 51, 52 Rotor magnetic pole

Claims (5)

An axial gap motor in which the stator and the rotor face each other,
In the stator, the same number of stator magnetic poles that are excited by energization of concentrated winding coils on the inner peripheral side and the outer peripheral side of the magnetic pole surface facing the rotor are arranged in the circumferential direction,
The stator gap on the inner circumference side of the stator is excited to one polarity, and the stator pole on the outer circumference side of the stator is excited to the other polarity opposite to the one pole. The axial gap motor according to claim 1,
An axial gap motor characterized in that the rotor magnetic pole on the inner peripheral side and the rotor magnetic pole on the outer peripheral side of the stator are displaced in the circumferential direction. The axial gap motor according to claim 1 or 2,
The stator magnetic pole on the inner peripheral side and the stator magnetic pole on the outer peripheral side of the stator are characterized in that the magnetic pole surface of the stator magnetic pole on the inner peripheral side has a vertically long shape, and the magnetic pole surface of the stator magnetic pole on the outer peripheral side has a horizontally long shape. Axial gap motor. The axial gap motor according to any one of claims 1 to 3,
The stator includes an axial gap motor including a loop-shaped field coil disposed between an inner peripheral stator magnetic pole and an outer peripheral stator magnetic pole. The axial gap motor according to claim 4,
In the rotor, an inner peripheral rotor magnetic pole and an outer peripheral rotor magnetic pole are arranged in a circumferential direction on a magnetic pole surface facing the stator,
The field coil protrudes in the direction of the rotor from the stator pole on the inner peripheral side and the stator pole on the outer peripheral side, and is not in a recess formed by a gap between the rotor magnetic pole on the inner peripheral side of the rotor and the rotor magnetic pole on the outer peripheral side. An axial gap motor that is inserted into a contact state.