JP2012034458A - Axial gap motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve motor characteristics by reducing non-opposing magnetic fluxes of a stator and a rotor of an axial gap motor without adding a new member.SOLUTION: A stator 5 has stator cores 8 each formed into a shape of a fan with its center part cut off. Each of rotors 4a and 4b has rotor cores 12 that are formed similarly to the stator cores 8. At least one of each of the stator cores 8 and each of the rotor cores 12 is tapered at its radially inner side where there is a narrow space between adjacent cores by being flexed inward to extend the space between the adjacent cores. Thus, non-opposing magnet fluxes of the stator 5 and the rotors 4a and 4b are reduced, and motor characteristics are improved, without adding a new member.

Description

  According to the present invention, a substantially sector-shaped stator core (more precisely, a shape in which a center point portion is cut out from a sector shape) having a radial stator pole pair constituted by a pair of magnetic poles of an outer diameter side and an inner diameter side is arranged in the circumferential direction. More specifically, the present invention relates to an improvement in characteristics such as a reduction in leakage magnetic flux.

  Conventionally, there are various types of axial gap motors in which the stator and the rotor are arranged in the direction of the motor shaft so that the magnetic pole surfaces face each other.

  The present applicant has a stator in which the above-mentioned substantially sector-shaped stator core having a radial stator pole pair composed of a pair of magnetic poles on the outer diameter side and the inner diameter side is disposed in the circumferential direction, and a substantially fan-shaped stator having a rotor magnetic pole. An axial gap motor provided with a rotor having a rotor core disposed in the circumferential direction has already been invented and applied (Japanese Patent Application No. 2010-058974).

  FIG. 11 shows the axial gap motor 101 of the above-mentioned application. The axial gap motor 101 is one (front side) stator 103a, rotor 104, and the other (back side) in order from the output side of the motor shaft 102 (the front side on the left side of the paper). The stator 103b is provided with a gap (gap) so that the magnetic pole faces face each other. In addition, the broken line in a figure shows the non-opposing magnetic pole of stator 103a, 103b.

  The stators 103a and 103b on both sides of the rotor 104 have a single-sided magnetic pole configuration in which the magnetic pole surface faces the rotor 104. The double-sided magnetic rotor 104 has both sides of the magnetic pole surface and is supported by the motor shaft 102 and rotated. To do.

  12A and 12B show the stators 103a and 103b. The axial gap motor 101 is a three-phase reluctance motor of A, B, and C, and the stators 103a and 103b are fan-shaped, for example, formed of a dust core having a stator magnetic pole pair 131. A stator core 132 having a shape with a part cut away is provided at intervals of 30 degrees in the circumferential direction. The stator magnetic pole pair 131 has teeth of a pair of magnetic poles 131a and 131b protruding in the direction of the rotor 104 on the outer diameter side and the inner diameter side, and the teeth are connected by a core 131c.

  The stator core 132 having the stator magnetic pole pairs 131 of the respective stators 103a and 103b is fitted with non-magnetic metal ring bodies 151 and 152 on the outer diameter side and inner diameter side in a radially arranged state. And is fixed in an annular shape in a magnetically independent state. A space (gap) between the stator cores 132 having the stator pole pairs 131 is a space for reducing the weight.

  Each of the stator magnetic pole pairs 131 of the stators 103a and 103b, for example, forms a magnetic pole pair of each phase in the order of A phase, B phase, and C phase clockwise when viewed from the front side, and each of the four magnetic pole pairs shifted by 90 degrees. A magnetic pole pair is a magnetic pole pair in which each phase is excited simultaneously.

  In each of the stators 103a and 103b, each of the stator magnetic pole pairs 131 has an extremely large number and quantity of coils of the stators 103a and 103b when a concentrated winding exciting coil is provided for each of the magnetic poles 131a and 131b. The portion of the core 131c between the magnetic poles 131a and 131b is provided with an exciting coil 106 that is commonly used for exciting the magnetic poles 131a and 131b, and is formed so as to minimize the number and amount of coils of the stators 103a and 103b. In this case, for example, when each A-phase excitation coil 106 is energized, the magnetic flux of each excitation coil 106 passes through each stator magnetic pole pair 131 in the radial direction so that the magnetic poles 131a and 131b have N poles and S poles (or their poles). On the contrary, it is excited. Each exciting coil 106 is drawn out to a pair of terminals of each phase by a connecting wire 161 on the outer diameter side and inner diameter side.

  FIG. 13A shows a magnetic pole surface on the front side of the rotor 104, for example, and the rotor 104 has a fan-shaped pair of rotor magnetic poles 141 as rotor magnetic poles on both the front and back surfaces. 8 rotor cores 142 are provided at intervals of 45 degrees in the circumferential direction, and the front and back are symmetrical. Each rotor magnetic pole pair 141 has a configuration in which teeth of the pair of magnetic poles 141a and 141b on the outer diameter side and the inner diameter side facing the pair of magnetic poles 131a and 131b of the stators 103a and 103b are connected by the core 141c. Similarly to 131, nonmagnetic metal ring bodies 191 and 192 on the outer diameter side and inner diameter side are fitted and fixed radially (annular).

  Each rotor magnetic pole pair 141 on the front and back sides of the rotor 104 is actually formed by integrally forming a magnetic pole pair on the front and back sides of, for example, a dust core rotor core (yoke). 142) are insulated by a gap between the cores 142 and are magnetically independent.

  FIG. 13B is a perspective view of the rotor 104 when the rotor magnetic pole pairs 141 on the front and back sides are integrally formed by a common yoke of the dust core, and each rotor core 142 of the dust core has a magnetic pole 141a on the front and back. , 141b protruding teeth are formed, and the teeth are connected by a concave core 141c.

  When the stators 103a and 103b and the rotor 104 are assembled as shown in FIG. 11, the portions of the excitation coil 106 mounted on the stator magnetic pole pairs 131 of the stators 103a and 103b that protrude in the direction of the rotor 104 are It fits in a recess of the core 141c between the teeth so as to be freely rotatable. Further, the thin portion on the outer diameter side of the rotor 104 faces the protruding thick portion on the outer diameter side of the stator 103a, 103b, and the inner diameter of the rotor 104 faces the thin portion on the inner diameter side of the stator 103a, 103b. Thick portions protruding toward the stators 103a and 103b on the side face each other.

  The axial gap motor 101 configured as described above operates by energizing each phase of the exciting coil 6 in the order of A phase, B phase, and C phase.

  In the above-mentioned existing application, an annular field coil is disposed on the stators 3a and 3b so as to overlap the respective excitation coils 6 of the stators 3a and 3b, and a DC field flux of the field coil is applied to the stator 3a. It is also described that torque is increased by increasing the amount of magnetic flux by superimposing the magnetic flux on the magnetic flux of each stator pole pair 31 of 3b in a lump.

  On the other hand, in a radial gap motor in which the stator is coaxially arranged on the outer peripheral side of the rotor so that the magnetic pole surfaces face each other, a magnetic flux shielding part or a magnetic flux shielding member is provided as magnetic flux shielding means to shield the magnetic flux to unnecessary portions. Therefore, it has been proposed to improve motor characteristics by improving motor characteristics (for example, Patent Document 1 (Abstract, Claim 1, Paragraphs [0042]-[0049], FIG. 1), Patent Document 2) (See abstract, claim 1, paragraphs [0031]-[0042], FIG. 1 etc.)).

  FIG. 14 shows an SR motor 201 that is a radial gap motor described in Patent Document 1. The SR motor 200 includes a rotor 202 as a rotor, a stator 203 as a stator, a motor housing (not shown) that accommodates these, and the like. Configured.

  The rotor 202 is configured by inserting an output shaft (shaft) 205 into a through hole formed at the center of a rotor core having four salient poles 202a.

  The stator 203 includes a stator core and a plurality of winding coils 207. The stator core is configured by integrally providing six salient poles 203a projecting in the radial direction inside a substantially cylindrical yoke portion.

  The rotor 202 is coaxially inserted and arranged so as to have a predetermined gap with the salient pole 203a of the stator 203. A winding coil 207 wound around a bobbin is attached to each salient pole 203a of the stator 203.

  Nonmagnetic conductive films (magnetic flux shielding portions) 209a and 209b are formed on both sides of each salient pole 202a of the rotor 202 and on the surface between salient poles (a portion between the salient pole 202a and the salient pole 202a adjacent thereto), respectively. , 209c are formed. The nonmagnetic conductive films 209a, 209b, and 209c are formed by evaporating aluminum.

  When the current flows through the pair of winding coils 207, the SR motor 201 generates a magnetic flux from the salient pole 203a of the stator 203 toward the salient pole 202a of the rotor 202, and the salient pole 202a of the rotor 202 existing in the vicinity thereof. Is attracted to the salient pole 203a, and the rotor 202 rotates and operates.

  At this time, when the winding coil 207 is energized, magnetic flux from the salient pole 203a of the stator 203 toward the tip of the salient pole 202a of the rotor 202 and leakage flux toward the side of the salient pole 2a and the portion between the salient poles are generated. The leakage magnetic flux is generated in accordance with the change in the magnetic flux passing through the nonmagnetic conductive films 209b and 209c formed on both sides of the salient pole 202a of the rotor 202 and the nonmagnetic conductive film 9a formed between the salient poles. The magnetic flux that effectively prevents the change and contributes to the generation of the rotational torque increases, and the torque (output) of the SR motor 1 is improved.

  FIG. 15 shows an SR motor 301 that is a radial gap motor described in Patent Document 2. The SR motor 301 also includes a rotor 302 as a rotor, a stator 303 as a stator, a motor housing (not shown) that accommodates these, and the like. Configured.

  The rotor 302 is configured by inserting an output shaft (shaft) 305 into a through hole formed at the center of a rotor core 304 having four salient poles 302a and fixing them integrally.

  The stator 303 includes a stator core 306 and a plurality of winding coils 307. The stator core 306 is configured by integrally providing six salient poles 303a projecting in the radial direction inside a substantially cylindrical yoke portion. The stator 303 is fixed inside the motor housing.

  The rotor 302 is coaxially inserted and disposed so as to have a predetermined gap with the salient pole 303a of the stator 303. Winding coils 307 wound around bobbins 308 are mounted on the salient poles 303a of the stator 303, respectively.

  Nonmagnetic conductive films (magnetic flux shielding members) 309a and 309b are formed on the outer surfaces of the pair of side walls of the bobbin 308, respectively. The nonmagnetic conductive films 309a and 309b are formed by evaporating aluminum.

  When a current flows through the pair of winding coils 307 of each phase, a magnetic flux is generated from the salient pole 303a of the stator 303 toward the salient pole 302a of the rotor 302, and the salient pole 302a of the rotor 302 existing in the vicinity thereof is generated. By being attracted, the rotor 302 rotates.

  By the way, when a magnetic flux is generated from the salient pole 303 a of the stator 303 to the salient pole 302 a of the rotor 302 by energization of the winding coil 307, a part thereof passes through the side wall portion of the bobbin 308. At this time, an eddy current is generated in the nonmagnetic conductive films 309a and 309b formed on the side wall of the bobbin 308, and this eddy current prevents the change of the magnetic flux, thereby increasing the magnetic flux that effectively contributes to the generation of the rotational torque. The output torque of the SR motor 301 is increased.

JP 2001-28851 A JP 2000-2341917 A

  In the axial gap motor as described in the above-mentioned application, it is desired to further increase the output and torque by reducing the leakage magnetic flux between adjacent cores and the non-opposing magnetic flux between the stator and the rotor.

  In this case, as in the radial gap motors of Patent Documents 1 and 2, a magnetic flux shielding unit (nonmagnetic conductive films 209a, 209b, 209c) or a magnetic flux shielding member (nonmagnetic conductive films 309a, 309b) is provided as magnetic flux shielding means. , Shielding the magnetic flux to unnecessary parts, reducing the magnetic flux leakage from the stator core that is energized to the adjacent stator core (that is, the magnetic flux leakage between the adjacent cores) and the non-opposing magnetic flux between the stator and the rotor. It is conceivable to improve the output and torque, but as a magnetic flux shielding part and magnetic flux shielding member, non-magnetic / conductive material is deposited or plated on the unnecessary part, or a conductive plate or conductive material is filled. It is necessary to add a new member, which increases costs and increases the weight and the motor size.

  According to the present invention, in this type of axial gap motor, the non-opposing magnetic flux between the stator and the rotor is reduced and the motor characteristics are improved without adding a new member such as vapor deposition or plating of a nonmagnetic / conductive material. Another object is to further improve motor characteristics by reducing leakage magnetic flux between adjacent cores.

  In order to achieve the above-described object, an axial gap motor of the present invention has a radial stator magnetic pole pair composed of a pair of magnetic poles on the outer diameter side and the inner diameter side, and has a shape in which a center point portion is notched from a sector shape. An axial gap motor comprising: a stator having a stator core disposed in a circumferential direction; and a rotor having a rotor magnetic pole and a rotor core formed by cutting out a central point portion from a sector shape, the stator core and the rotor core At least one of these is characterized in that both sides are formed in a tapered shape that is bent inward on the inner diameter side (Claim 1).

  The tapered portion on the inner diameter side is preferably formed so that the adjacent cores are parallel to each other (Claim 2).

  Further, in order to reduce the leakage magnetic flux between adjacent cores and improve the motor characteristics, it is desirable that the back side of the magnetic pole on the outer diameter side of the stator core is chamfered so as to widen the interval between the adjacent cores. (Claim 3).

  In the case of the axial gap motor of the present invention according to claim 1, at least one of the stator core and the rotor core having a sector-shaped center point portion, particularly the inner diameter side where the interval between adjacent cores is narrowed inwardly. Formed in a tapered shape and widened between adjacent cores, eliminating the need for vapor deposition or plating of non-magnetic and conductive materials, reducing the non-opposing magnetic flux between the stator and rotor without adding new components Thus, the motor characteristics can be improved, and the output and torque of the motor can be increased.

  In the case of the axial gap motor of the present invention according to claim 2, since the tapered portion on the inner diameter side is formed so that the adjacent cores have a parallel interval, the interval between the adjacent cores on the inner diameter side is uniform. Thus, the non-opposing magnetic flux between the stator and the rotor can be further reduced to increase the motor output and torque, and the magnetic pole area can be secured.

  In the case of the axial gap motor of the present invention according to claim 3, the outer diameter side portion of the stator core is cut into a chamfered shape so as to widen the interval between adjacent cores while leaving the magnetic pole and passing the magnetic flux on the back side. Thus, without reducing the magnetic pole area, the leakage magnetic flux between adjacent cores can be reduced to improve the motor characteristics, and the motor output and torque can be further increased.

It is sectional drawing of the axial gap motor of one Embodiment of this invention. It is a front view of the magnetic pole surface of the stator of the axial gap motor of FIG. It is a rear view of the rotor of the axial gap motor of FIG. FIG. 3 is a perspective view of the stator core of FIG. 2. . (A), (b), (c) is the front view seen from the magnetic pole surface of the stator core of FIG. 4, a side view, and a rear view. 2A is an explanatory diagram of the spacing on the outer diameter side of the adjacent core on the magnetic pole surface side of the stator in FIG. 2, and FIG. FIG. (A), (b) is explanatory drawing of the shape of the magnetic pole of the inner diameter side of the stator core of the stator of FIG. FIG. 4 is a perspective view of a rotor core of the rotor of FIG. 3. (A), (b), (c) is the front view seen from the magnetic pole surface of the rotor core of FIG. 8, a side view, and a rear view. (A) is explanatory drawing of the magnetic pole space | interval of the internal diameter side of the non-opposing part of the stator and rotor of the axial gap motor of FIG. 1, (b) is explanatory drawing of the space | interval of the internal diameter side of the adjacent core of a stator. It is sectional drawing of the axial gap motor of an existing application. (A), (b) is the rear view and front view which looked at the other stator of FIG. 11 from the left side of the paper surface. (A), (b) is the front view and perspective view which looked at the rotor of FIG. 11 from the left side of the paper surface. It is sectional drawing of an example of the conventional radial gap motor. It is sectional drawing of the other example of the conventional radial gap motor.

  Next, in order to describe the present invention in more detail, an embodiment will be described in detail with reference to FIGS. In these drawings, the motor shaft and the like are omitted as appropriate.

  FIG. 1 shows a partial cross-section along the motor shaft 2 of the axial gap motor 1 of the present embodiment. The axial gap motor 1 has a front side (left side in the drawing) of the same shape for attaching a rotor to be described later to the motor shaft 2. Rear flange shafts 3a and 3b are attached. The flange shafts 3a and 3b have a shape in which a cylindrical support portion 32 is attached to the outer periphery of a disc-shaped flange portion 31 through which the motor shaft 2 penetrates the center.

  One annular (front side) rotor 4 a is attached to the front support portion 32. On the rear side, an annular stator 5 in which both surfaces are formed as magnetic pole surfaces and the motor shaft 2 passes through the central opening is disposed. Furthermore, the annular rear (back side) rotor 4b is attached to the rear support portion 32 behind the rear portion. In this way, the rotor 4a supported by the motor shaft 2 via the flange shaft 3a, the rotor 4a supported by the motor shaft 2 via the flange shaft 3a, the stator 5 and the rotor shaft 4b supported by the motor shaft 2 in this order from the front side. The magnetic pole faces are arranged to face each other. At least the flange shafts 3a and 3b are both made of a non-magnetic material such as stainless steel.

  The stator 5 is formed, for example, by joining a front-side split stator 51 and a rear-side split stator 52 with a partition plate 53 in between, and the split stators 51 and 52 are ring bodies made of non-magnetic metal on the outer diameter side and inner diameter side. 6a and 6b are fitted and integrated. Further, a resin cover 7 that covers a pair of terminals and the like of each phase is provided on the outer side of the ring body 6a on the outer diameter side. In addition, the solid line of FIG. 1 and the broken arrow line loop show the loop of the magnetic flux of each of the divided stators 51 and 52.

  FIG. 2 shows the magnetic pole surface on the surface side of the split stator 51 that forms one magnetic pole surface of the stator 5. The divided stators 51 and 52 have the same configuration, and the axial gap motor 1 is a reluctance motor of three-phase drive of A, B, and C similar to the axial gap motor 101 of the already-filed application.

  In the divided stators 51 and 52, for example, 12 stator cores 8 formed of a powder magnetic core (four at intervals of 90 degrees per phase) are arranged at intervals of 30 degrees in the circumferential direction. A gap between the stator cores 8 (between adjacent cores) is a space or a non-magnetic resin filling portion, and each stator core 8 is magnetically independent.

  Each stator core 8 has a shape in which a central point portion is cut out from a fan shape when viewed from the front, and the protruding teeth of a pair of magnetic poles 9a and 9b on the outer diameter side and inner diameter side are connected by a yoke portion 9c between the magnetic poles. It has a radial stator pole pair 9.

  Excitation coils 10 for each phase that are shared by the magnetic poles 9a and 9b of the stator magnetic pole pair 9 are mounted on the yoke portion 9c of each stator core 8. In the case of this embodiment, the exciting coil 10 is formed of a so-called cassette coil in order to facilitate mounting. In this case, the mounting of the exciting coil 10 is completed by a simple operation of attaching the coil bobbin around which the cassette coil is wound to the yoke portion 9c. The exciting coil 10 may be formed by directly winding a coil (enameled wire) around the yoke portion 9c.

  By the way, in this embodiment, in order to increase the amount of magnetic flux and increase the motor output (torque output), on both magnetic pole surface sides of the stator 5, it overlaps with the excitation coil 6 of the yoke portion 9 c of each stator magnetic pole pair 9. In addition, an annular field coil 11 is arranged, and the DC field magnetic flux of the field coil 11 is collectively superposed on the excitation magnetic flux of each stator pole pair 9 to increase the amount of magnetic flux.

  FIG. 3 is a rear view of the rotor 4 a as viewed from the front side of the axial gap motor 1. The rotors 4a and 4b have the same configuration. For example, eight rotor cores 12 formed of, for example, dust cores are arranged at intervals of 45 degrees in the circumferential direction, and each rotor core 12 has an outer diameter side and an inner diameter side. Non-magnetic metal ring bodies 13a and 13b are fitted and fixed radially (annular). The gap between the rotor cores 12 (between adjacent cores) is, for example, a non-magnetic resin filling portion 14, and each rotor core 12 is also magnetically independent.

  Similarly to the stator core 8, each rotor core 12 has a shape in which a central point portion is cut out from a fan shape when viewed from the front, and the protruding teeth of the pair of magnetic poles 15a and 15b on the outer diameter side and inner diameter side are provided as yoke portions 15c between the magnetic poles. And a pair of radial rotor magnetic poles 15 connected together. Similarly to the stator magnetic pole pair 8, each rotor magnetic pole pair 11 has a shape in which a central point portion is cut out from a fan shape when viewed from the front, and the magnetic poles 15 a and 15 b of the rotor 4 a are rotated by the rotation of the rotors 4 a and 4 b. The magnetic poles 9a and 9b are opposed to and not opposed to each other, and the magnetic poles 15a and 15b of the rotor 4b are opposed to and opposed to the magnetic poles 9a and 9b of the split stator 52.

  When, for example, the A-phase excitation coil 10 of the divided stators 51 and 52 is energized, the magnetic flux of the excitation coil 10 of the A-phase stator magnetic pole pair 9 passes through the stator magnetic pole pair 9 in the radial direction, for example, the magnetic pole 9a. 9b are excited to the N pole and the S pole, and a magnetic flux loop of solid lines and broken arrow lines in FIG. The axial gap motor 1 is rotated by magnetic attraction between the rotors 4a and 4b and the stator 5 based on the magnetic flux loop.

  By the way, in this embodiment, in order to increase the motor output and the torque by reducing the leakage magnetic flux between adjacent cores without vaporizing or plating a nonmagnetic / conductive material, (1) each of the stator 5 The shape of the stator core 8 is processed to reduce the leakage magnetic flux between adjacent stator cores 8 (between adjacent cores) so that local magnetic saturation does not occur. (2) A core shape that reduces the non-opposing magnetic flux between the rotors 4a and 4b and the stator 5 is provided.

  First, the shape of the stator 5 that reduces the leakage magnetic flux of (1) will be described in further detail. In this case, it is easier to reduce or cut the magnetic path of the leakage magnetic flux on the outer diameter side where the interval between adjacent cores is wider than on the inner diameter side where the interval between adjacent cores becomes narrower. Therefore, the leakage magnetic flux between adjacent cores is reduced by processing at least the outer diameter side of the stator core 8.

  4 is a perspective view of the stator core 8 as seen from its magnetic pole surface. FIGS. 5A, 5B, and 5C are a front (magnetic pole surface) view, a right side view, and a rear view of the stator core 8. FIG. As is clear from these drawings, each stator core 8 is cut into a chamfered shape so that the left and right sides of the yoke portion 9d on the back side of the magnetic pole 9a on the outer diameter side are widened so as to widen the interval between adjacent cores (adjacent stator cores 8). ing.

  At this time, in order to reduce the leakage magnetic flux between the stator cores 8 without causing a certain magnetic saturation, in each stator core 8, (i) the magnetic poles 9a and 9b ensure a sufficient magnetic pole area. Further, the outer diameter side magnetic pole 9a is formed in a predetermined thickness (thickness α in FIG. 5B) in the direction of the motor shaft 2 so as to ensure a sufficient path for the magnetic flux. (Ii) The yoke portion 9d on the back side of the magnetic pole 9a on the outer diameter side is formed by chamfering so that the circumferential width (lateral width) gradually decreases toward the outer diameter direction and the interval between adjacent cores is increased. To do. At that time, in order to ensure that each stator core 8 is securely fixed and held by the ring bodies 6a and 6b, and to secure a magnetic path in the inner diameter direction, the yoke portion 9d is provided at the outermost outer diameter side end portion. Then, as shown in FIG. 5C, the horizontal width β (α ≧ β) is cut to the left and right so as to secure a plane or curved surface portion having a constant horizontal width in the circumferential direction.

  In this way, the portion on the back side of the magnetic pole surface of the stator 5 has a longer circumferential distance on the outer diameter side between adjacent cores, and a sufficient magnetic pole area is ensured by the fan-shaped magnetic pole shape. By processing the yoke portion 9d that becomes gradually narrower, the spatial distance between the adjacent stator cores 8 can be widened, and the leakage magnetic flux between the stator cores 8 can be reliably reduced.

  6A shows the interval between adjacent cores when a part of the divided stator 51 is viewed from the magnetic pole surface side, and FIG. 6B shows the interval between adjacent cores when viewed from the yoke portion 9d on the back side of the same part. As is clear from the comparison of the arrow lines between the stator cores 8 in these drawings, the back side of the magnetic pole 9a on the outer diameter side of the stator core 8 increases the spatial distance between the adjacent stator cores 8 by processing the yoke portion 9d. As a result, the leakage magnetic flux between the stator cores 8 is reduced.

  For example, in order for the magnetic flux in the internal magnetic path of each stator core 8 to advance from the magnetic pole 9b of the stator magnetic pole pair 9 to the magnetic pole 9a as shown by the arrow line in FIG. Although it is necessary to disperse the magnetic flux, if machining is performed so that α ≧ β and the thickness α of the magnetic pole 9a is greater than or equal to the left and right cutting length β of the circumferential width at the outermost peripheral portion of the yoke portion 9d, the motor shaft 2 direction A sufficient bending portion can be secured for the magnetic flux incident on the magnetic head to go in the circumferential direction and further in the axial direction, and no magnetic saturation occurs.

  Next, the core shape for reducing the non-opposing magnetic flux of (2) will be described in detail. The non-facing magnetic flux becomes a problem on the inner diameter side where the core interval becomes narrower than on the outer diameter side where the core interval becomes wider. Therefore, the core shape on the inner diameter side is improved. That is, the magnetic poles 9b and 15b on the inner diameter side of the stator core 8 and the rotor core 12 and the back side portions thereof have substantially the same shape, and have a tapered shape centering on the outer diameter side of the magnetic poles 9a and 15a on the outer diameter side. To do.

  First, the core shape of the stator 5 will be described.

  FIG. 7 is an explanatory diagram of the shape of the stator core 8 on the inner diameter side. As shown in FIG. 7A, the stator core 8 has a magnetic pole 9a on the outer diameter side in conformity with a sector shape based on the center point Pa. When the magnetic pole 9x is formed in a shape having the inner diameter side magnetic pole 9x together with the yoke portion 9c, the magnetic pole 9x has a relatively long lateral width (the length in the circumferential direction), and its magnetic pole area is the same as that of the magnetic pole 9a. The length is lx. In this case, when the stator core 8 is disposed in the circumferential direction, the circumferential interval between the magnetic poles 9x on the inner diameter side is short, and even when not facing each other, the magnetic pole 9x on the inner diameter side and the inner diameter side of the rotor core 12 of the rotors 4a and 4b. Even if the spatial distance to the magnetic pole 15b is short and it is in a non-opposing state, unnecessary magnetic flux is generated by the fringing magnetic path connecting the stator magnetic pole surface and the rotor magnetic pole side surface, and the rotor magnetic pole surface and the stator magnetic pole side surface. Output and torque decrease.

  Therefore, in the present embodiment, as shown in FIG. 7B, the stator core 8 is formed in a tapered shape in which both sides are bent inward on the inner diameter side, and the interval between adjacent cores of the magnetic pole 9b on the inner diameter side is increased. Reduce the opposing magnetic flux. That is, the magnetic pole 9a and the yoke portion 9c on the outer diameter side are formed in a sector shape with respect to the center point Pa, and the magnetic pole 9b on the inner diameter side is based on the center point Pb set closer to the outer diameter than the center point Pa. The fan-shaped shape is formed. In this case, the left and right sides of the magnetic pole 9b are bent inwardly of the magnetic pole 9x, and the radial length lb of the magnetic pole 9b is slightly longer than lx. The distance increases, and when it is not opposed, the spatial distance between the magnetic pole 9b on the inner diameter side and the magnetic pole 15b on the inner diameter side of the rotor core 12 of the rotors 4a and 4b is increased, and generation of unnecessary magnetic flux is reduced to increase motor output and torque. . In order to prevent a decrease in magnetic flux at the time of facing, the portion on the back side of the magnetic pole 9b on the inner diameter side is also formed in the same shape as the magnetic pole 9b. The position of the center point Pb is preferably a position closer to the outer diameter side than the center of the motor shaft 2.

  Next, the core shape of the rotors 4a and 4b will be described. Not only the stator 5 but also the rotors 4a and 4b have the same core shape, so that the magnetic pole 9b on the inner diameter side of the stator 5 and the magnetic pole 15b on the inner diameter side of the rotor core 12 of the rotor 4a and 4b when not facing each other. , The generation of unnecessary magnetic flux decreases, and the motor output and torque increase.

  FIG. 8 is a perspective view of the rotor core 12 as viewed from its magnetic pole surface. FIGS. 9A, 9B, and 9C are a front (magnetic pole surface) view, a right side view, and a rear view of the rotor core 12, respectively.

  Also, as shown in FIG. 9A, the rotor core 12 is also formed so that both sides are tapered inwardly on the inner diameter side, and the interval between the magnetic poles 15 b on the inner diameter side is set to the magnetic pole 9 b on the inner diameter side of the stator core 8. Same interval as. That is, the magnetic pole 15a and the yoke portion 15c on the outer diameter side are formed in a fan shape with respect to the center point Qa, and the magnetic pole 15b on the inner diameter side is based on the center point Qb set closer to the outer diameter than the center point Qa. The fan-shaped shape is formed. In addition, when making the shape of the rotor core 12 seen from the magnetic pole face the same shape as the stator core 8, Qa = Pa and Qb = Pb. Further, in the case of the rotor core 12, the problem of leakage magnetic flux between the adjacent cores does not occur, so the back side portions of the magnetic poles 15a and 15b are formed in the same plane shape as the surface side.

  FIG. 10A is a state view of a part of the non-opposing state of the axial gap motor 1 as seen from the output side, and the interval between the magnetic poles 8b and 15b on the inner diameter side of the stator core 8 and the rotor core 15 increases as indicated by the arrow line. Thus, it is possible to secure a sufficient spatial distance between the magnetic poles 8b and 15b on the inner diameter side and reduce the magnetic flux.

  By the way, since the interval in the circumferential direction of the magnetic pole 9b on the inner diameter side of the stator core 8 becomes longer, there is an advantage that the magnetic path of the leakage magnetic flux described above can be reduced also on the inner diameter side.

  FIG. 10B shows the reduction of the magnetic path of the leakage magnetic flux on the inner diameter side, and as indicated by the arrow line, the circumferential interval of the magnetic pole 9b on the inner diameter side of the stator core 8 becomes longer, and the leakage also occurs on the inner diameter side. The magnetic path of the magnetic flux decreases.

  Further, as shown in FIGS. 6A, 6B, and 10B, the portion of the magnetic pole 9b, which is a tapered portion on the inner diameter side of the stator core 8, is appropriately set in the shape of the magnetic pole 9b. If it is formed so that the adjacent cores are parallel to each other when viewed from the front (from the front), the distance between the adjacent cores on the inner diameter side is evenly spread, the non-opposing magnetic flux is further reduced, and the motor output is increased. Moreover, there is an advantage that the magnetic pole area of the magnetic pole 9b can be secured. In addition, the magnetic path cross-sectional area for allowing the magnetic flux entering from the magnetic pole 9b to travel in the outer diameter direction through the stator core 8 is easily secured, and there is an advantage that magnetic saturation does not easily occur.

  As described above, in the present embodiment, the non-opposing magnetic flux between the stator 5 and the rotors 4a and 4b can be reduced to improve the motor characteristics (torque and output). Further, the leakage flux between the stator cores 8 of the stator 5 can be reduced and the motor characteristics can be further improved without causing local magnetic saturation. Further, there is no need to vapor-deposit or plate a nonmagnetic / conductive material, and no new members are added, so that the mass and cost of the axial gap motor 1 do not increase.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit thereof, for example, processing on the outer diameter side of the stator core 8 No improvement is made, and only the improvement of the core shape on the inner diameter side (machining of the magnetic poles 9b and 15b on the inner diameter side into a tapered shape) is performed to reduce the non-opposing magnetic flux between the stator 5 and the rotors 4a and 4b. Output) may be improved. In this case, since the effect can be obtained by processing the magnetic poles 9b and 15b on the inner diameter side into a tapered shape for at least one of the stator 5 and the rotors 4a and 4b, the improvement of the core shape on the inner diameter side can be improved. What is necessary is just to perform about at least any one of 4a and 4b.

  Finally, the number of magnetic poles of the rotors 4a and 4b and the stator 5 of the axial gap motor 1 may be whatever, and the mounting structure of the rotors 4a and 4b to the motor shaft 2 may be different from that of the above embodiment. Of course.

  Further, the present invention can be similarly applied to an axial gap motor having a single-sided magnetic pole surface of a stator configured by, for example, the rotor 4a and the split stator 51.

  The present invention can be applied to an axial gap motor for various uses such as a drive motor for an electric vehicle.

DESCRIPTION OF SYMBOLS 1 Axial gap motor 4a, 4b Rotor 5 Stator 8 Stator core 9 Stator magnetic pole pair 9a, 9b pair magnetic pole 12 Rotor core 15 Rotor magnetic pole pair 15a, 15b pair magnetic pole

Claims (3)

A stator having a pair of magnetic poles in the radial direction composed of a pair of magnetic poles on the outer diameter side and the inner diameter side and having a stator core having a shape in which a center point portion is cut out from a sector shape and a sector shape having a rotor magnetic pole. An axial gap motor having a rotor core formed in a circumferential direction with a rotor core formed by cutting out the center point portion from
At least one of the stator core and the rotor core is formed in a tapered shape in which both sides are bent inward on the inner diameter side. The axial gap motor according to claim 1,
The taper portion on the inner diameter side is formed so as to have a parallel interval between adjacent cores. The axial gap motor according to claim 1 or 2,
An axial gap motor, wherein the back side of the magnetic pole on the outer diameter side of the stator core is cut into a chamfered shape so as to widen the interval between adjacent cores.

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