JP2009038897A - Axial gap motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial gap motor for reducing the flow of a magnetic flux in a radial direction by uniforming the density of magnetic flux inside teeth, suppressing an extreme decrease in a magnetic torque, increasing a reluctance torque and solving problems caused by magnetic saturation of a back yoke. <P>SOLUTION: In the axial gap motor, a circular region 40 where a magnetic pole surface 22 faces the teeth 34 in a direction of a rotary shaft 90 includes a circle having a predetermined width ¾R1-R2¾ in the radial direction while a proportion between circumferential direction lengths LR1, LR2 of the magnetic pole surface 22 and circumferential direction lengths LS1, LS2 of the teeth 34 does not depend on the position of the radial direction around the rotary shaft 90. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an axial gap type motor in which a stator and a rotor face each other with a predetermined gap in the direction of a rotation axis.

  An axial gap type motor has the advantage that even if the thickness is reduced, the area of the magnetic pole surface can be sufficiently secured, and the axial coil of the armature can be easily wound in an aligned manner, so that copper loss can be reduced. is doing. In recent years, since it has become possible to use isotropic magnetic materials with high magnetic permeability and low iron loss, such as dust cores, axial gap motors for applications that require high output and high efficiency Research is also underway to adopt this.

  Furthermore, by using reluctance torque, copper loss can be reduced, torque can be improved, and an embedded magnet type axial gap type motor that can perform sensorless control using a large salient pole ratio. Research is also progressing.

  A related manufacturing method of an axial gap type motor is disclosed in, for example, Patent Document 1.

Japanese Patent Laid-Open No. 10-070875

  In the axial gap type motor, the permanent magnet is formed in a substantially sector shape according to the number of poles, and the teeth are also formed in a substantially sector shape or a substantially triangular shape according to the number of slots. Accordingly, the circumferential lengths of the permanent magnets and the teeth differ depending on the size of the radius around the rotation axis. For example, when the teeth are configured by laminating electromagnetic steel plates in the radial direction, the length in the circumferential direction of the electromagnetic steel plates varies depending on the radial position of the teeth. As a result, the magnetic flux density may be uneven in the radial direction. For example, in the innermost circumferential portion of the teeth in the radial direction, the circumferential length of the teeth is extremely small even though many magnets face each other. Therefore, this portion is magnetically saturated, or the flow of magnetic flux is a flow inclined in the radial direction.

  Due to this non-uniformity, the magnetic flux has a lot of radial components, so even if a laminated steel plate is used, the magnetic resistance is high and eddy current loss is often generated. In addition, when a dust core is used instead of a laminated steel plate, magnetic flux flows through the teeth in an inclined direction including the radial component, so the magnetic path becomes longer, the iron loss increases, and the magnetic resistance increases. Invite problems such as increase.

  Furthermore, in order to increase the reluctance torque in a field element of a conventional axial gap motor, if an attempt is made to sufficiently secure a magnetic path contributing to the generation of the torque, the occupation area of the permanent magnet must be reduced. In other words, there is a problem that the magnet torque decreases. On the other hand, if an attempt is made to suppress an extreme decrease in the magnet torque in the field element, there is a problem that a sufficient magnetic path for the magnetic flux that generates the reluctance torque cannot be secured. This problem becomes conspicuous as the number of poles increases.

  Furthermore, not only the conventional axial gap type motor but also a motor using all the reluctance torque has the following problems. That is, in a situation where a back yoke is provided on the permanent magnet of the field element and the back yoke is magnetically saturated, a so-called “cross saturation” phenomenon occurs, resulting in a decrease in rotor position estimation accuracy and stability of sensorless control. Cause a decline.

  Cross saturation means that the d-axis inductance Ld and the q-axis inductance Lq depend on both the d-axis current id and the q-axis current iq, respectively, in a situation where the back yoke of the motor is magnetically saturated. When this phenomenon occurs, the salient pole ratio decreases when the armature current is increased. In addition, the reluctance torque is reduced, and the estimation accuracy of the rotor position using the d-axis inductance Ld and the q-axis inductance Lq is lowered. As a result, the stability of sensorless control also decreases.

  Accordingly, in view of the above problems, the present invention provides a technique for reducing the magnetic flux component in the radial direction by uniforming the magnetic flux density inside the teeth and suppressing the extreme decrease in the magnet torque in the axial gap type motor. With the goal. It is another object of the present invention to provide a technique for increasing the reluctance torque and suppressing problems caused by magnetic saturation of the back yoke even when a back yoke is provided.

  In order to solve the above-mentioned problem, the first invention provides a rotor (20, 22a-22e) having a plurality of magnetic pole faces (22, 22a to 22e) arranged in an annular shape around the rotation axis (90) and alternating magnetic poles. 20a to 20e) and teeth (34) holding a plurality of armature windings (32) arranged in an annular shape around the rotation axis, and along the direction of the rotation axis, the rotor and An axial gap type motor (10, 10a to 10e) having a stator (30) facing each other through a predetermined gap, wherein the magnetic pole surface and the teeth face each other in the direction of the rotating shaft ( 40), the ratio of the circumferential length (LR1, LR2) around the rotation axis of the magnetic pole surface to the circumferential length (LS1, LS2) of the teeth is a diameter around the rotation axis. Independent of the position of the direction, Direction to a predetermined width (| R2-R1 |) comprises a circular ring having a axial gap motor.

  2nd invention is 1st invention, Comprising: The said teeth (34) are laminated | stacked in the said radial direction on the thin plate (36) extended in the said circumferential direction.

  3rd invention is 1st invention, Comprising: The said teeth (34) are laminated | stacked on the said radial direction by laminating | stacking the thin plate (37) extended in the direction orthogonal to the said radial direction.

  A fourth invention is any one of the first to third inventions, wherein the rotor (20, 20c) has a permanent magnet (23, 23c) having the magnetic pole surface (22, 22c) as a surface. The teeth (34) and the permanent magnet directly oppose each other through the gap.

  A fifth invention is any one of the first to third inventions, wherein the rotor (20a, 20b, 20d, 20e) includes a permanent magnet (23a, 23c) and the tooth ( 34) and a rotor magnetic core (24a, 24b, 24d) that exhibits the magnetic pole surfaces (22a, 22b, 22d, 22e).

  6th invention is 5th invention, Comprising: The said rotor magnetic core (24a, 24b, 24d) is laminated | stacked in the said radial direction on the thin plate (26) extended in the said circumferential direction. .

  7th invention is 5th invention, Comprising: The said rotor magnetic core (24a, 24b, 24d) laminates | stacks the thin plate (27) extended in the direction orthogonal to the said radial direction on the said radial direction. Configured.

  The eighth invention is any one of the first to seventh inventions, wherein the plurality of teeth (34) adjacent in the circumferential direction have substantially parallel sides facing each other in the circumferential direction.

  9th invention is 4th or 5th invention, Comprising: The said rotor (20, 20a, 20c-20e) is 1st magnetic between the said magnetic pole surfaces (22, 22a, 22c-22e). It further has a body (28).

  A tenth aspect of the invention is the ninth aspect of the invention, wherein the first magnetic body (28) is unevenly distributed on the inner peripheral side with respect to the outermost outer periphery of the magnetic pole surface (22, 22a, 22c to 22e).

  The eleventh invention is the ninth or tenth invention, further comprising a second magnetic body (29) for connecting the first magnetic bodies (28) to each other on the inner peripheral side in the radial direction.

  According to the first invention, the region where the magnetic flux density becomes uniform increases. In particular, on the inner peripheral side of the teeth, the flow of magnetic flux in the radial direction can be reduced, and magnetic saturation can be avoided or suppressed. Moreover, iron loss can be reduced.

  According to the 2nd and 3rd invention, since the flow direction of magnetic flux and the extending direction of a magnetic steel sheet correspond, iron loss can be reduced, making magnetic resistance low.

  According to the fourth invention, the magnetic flux density inside the teeth can be made more uniform.

  According to the fifth aspect of the present invention, even when a large current flows through the stator, the demagnetizing field is relaxed by the rotor core, so that a motor that is resistant to demagnetization can be provided. Moreover, since a coercive force is not required, a permanent magnet having a high magnetic flux density can be used.

  According to the sixth and seventh inventions, the magnetic flux moving in the radial direction inside the rotor core can be reduced, the magnetic flux density can be made uniform, and the magnetic resistance can be reduced. Moreover, iron loss can be reduced.

  According to the eighth aspect, the space between the teeth in which the armature winding is housed is constant in the radial direction, and the space factor of the armature winding is improved.

  According to the ninth aspect of the invention, since the magnetic body increases so-called q-axis inductance, it can contribute to a motor using reluctance torque.

  According to the tenth aspect, the portion of the rotor where no permanent magnet is provided can be used effectively, and the q-axis inductance can be increased. Furthermore, since the circumferential side of the magnetic pole surface of the rotor is inclined with respect to the radial direction, a rapid alternating of the magnetic poles of the rotor can be alleviated, so that the cogging torque can be suppressed.

  According to the eleventh aspect, the q-axis inductance can be further increased. Even when the back yoke is provided on the rotor, the magnetic flux path for generating the magnet torque and the magnetic flux path for generating the reluctance torque can be separated, so that magnetic saturation of the back yoke can be avoided or suppressed.

  Preferred embodiments of the present invention will be described below with reference to the drawings. In the following drawings including FIG. 1, only elements related to the present invention are shown.

<First Embodiment>
FIG. 1 is an exploded perspective view of an axial gap type motor 10 according to the first embodiment of the present invention, which is exploded along a rotating shaft 90. FIG. 2 is a perspective view of the rotor 20 viewed obliquely from the armature side, and FIG. 3 is an enlarged view of the teeth 34 included in the stator 30. Further, FIG. 4 is a plan perspective view of the axial gap type motor 10 viewed from the direction of the rotation axis 90. In this embodiment, the case where the number of poles is “8” (the number of pole pairs is “4”) and the number of slots is “12” is described as an example, but the present invention is not limited to this. Further, in the following drawings including FIG. 1, the armature winding 32 is shown wound only on one tooth 34, but actually the armature winding 32 is wound on all the teeth 34. Is provided.

  As shown in FIGS. 1 and 2, the axial gap type motor 10 is arranged in a ring shape with the rotor 20 having a plurality of magnetic pole faces 22 arranged in a ring shape around the rotation shaft 90 and in the ring shape around the rotation shaft 90. It has teeth 34 that hold a plurality of armature windings 32, and includes a stator 30 that faces the rotor 20 along the direction of the rotating shaft 90. Here, the rotor 20 includes a permanent magnet 23 having the magnetic pole surface 22 as a surface, and the teeth 34 and the permanent magnet 23 are directly opposed to each other through the predetermined gap. The magnetic pole surface 22 is arranged with alternating magnetic poles in the circumferential direction. Although disassembled and shown in FIG. 1, the stator 30 and the rotor 20 face each other with a predetermined gap in the assembled state as the axial gap type motor 10.

  Specifically, the rotor 20 includes a back yoke 21 that is formed in a substantially annular shape around a hole 25 that is fastened to a shaft (not shown) disposed along the rotation shaft 90, and the stator 30 side of the back yoke 21. And a plurality of permanent magnets 23 disposed on the surface. The permanent magnet 23 has a substantially arcuate cross-sectional shape with the rotation axis 90 as a normal line, and presents the magnetic pole surface 22 on the surface of the permanent magnet 23 with the rotation axis 90 as a normal line. The permanent magnet 23 is annularly arranged at a position where the focal point of the arch coincides with the rotation shaft 90 and with the magnetic poles alternating. That is, when the number of poles is “8”, the rotation axis 90 with respect to the annularly arranged permanent magnet 23 becomes an eight-fold symmetry axis.

  The rotor 20 further includes a first magnetic body 28 between the adjacent magnetic pole surfaces 22. The magnetic bodies 28 are unevenly distributed on the inner peripheral side with respect to the outermost periphery of the magnetic pole surface 22 and are connected to each other by the second magnetic body 29 on the inner peripheral side. That is, in the present embodiment, the rotation axis 90 is an eight-fold symmetry axis with respect to the first magnetic body 28 and the second magnetic body 29 as well. In FIG. 2, a two-dot chain line is provided between the first magnetic body 28 formed between the adjacent magnetic pole surfaces 22 and the second magnetic body 29 that connects the first magnetic bodies 28 on the inner peripheral side. Are distinguished from each other, but it is desirable that they are formed integrally.

  The back yoke 21, the first magnetic body 28, and the second magnetic body 29 are formed of a soft magnetic body or formed of a dust core that integrates both. Here, the first magnetic body 28, the second magnetic body 29, and the permanent magnet 23 are disposed with a predetermined gap in order to prevent a magnetic short circuit. The first magnetic body 28 and the second magnetic body 29 are referred to as a “reluctance score” 28A because they play a role of guiding a magnetic flux that generates reluctance torque. Alternatively, it is also referred to as a “q-axis core” because a component in the q-axis direction of the magnetic flux flows at a position where the first magnetic body 28 and the second magnetic body 29 are disposed. The shape of the reluctan score 28A will be described in detail later together with the relationship with the permanent magnet 23.

  The stator 30 includes a substrate 31 formed in a substantially annular shape around a through-hole 35 through which a shaft disposed along the rotation shaft 90 passes, and a surface on the side where the substrate 31 faces the rotor 20. , And a plurality of (for example, twelve) teeth 34 arranged radially, and armature windings 32 held by the teeth 34. Specifically, in the surface on the side facing the rotor 20, the substrate 31 has twelve fitting holes (or, radially) around the through hole 35 between the through hole 35 and the outer edge portion. Fitting recesses) are provided, and the teeth 34 are erected in the fitting holes. That is, when the number of slots is “12”, the rotation axis 90 with respect to the teeth 34 arranged radially is a 12-fold symmetry axis.

  Here, the material of the substrate 31 may be either a soft magnetic material or a non-magnetic material. In addition, since the board | substrate 31 can be applied as a back yoke of the teeth 34 by forming the board | substrate 31 with a soft magnetic body, it is desirable to use a soft magnetic body with high magnetic permeability. For example, it can be configured by electromagnetic steel plates laminated in the direction of the rotating shaft 90 in a shape provided with a buried hole for embedding the teeth 34.

  As shown in FIG. 3A, the teeth 34 erected on the stator 30 are configured by laminating thin plates 36 extending in the circumferential direction of the stator 30 in the radial direction of the stator 30. Or as shown in FIG.3 (b), the thin plate 37 extended in the direction orthogonal to a radial direction is laminated | stacked on a radial direction, and is comprised. In either case, the plurality of teeth 34 adjacent in the circumferential direction have substantially parallel sides facing each other in the circumferential direction.

  Further, the teeth 34 may have a flange portion 38 that protrudes at least in the circumferential direction from the upper end surface (the end surface facing the magnetic pole surface 22). If the flange portion 38 is provided, the upper surface (end surface facing the magnetic pole surface 22) 38S of the flange portion 38 can be regarded as the magnetic pole surface of the stator 30, so that the armature winding 32 is wound. The magnetic pole surface of the stator 30 can be expanded to the region where it is formed. Therefore, more magnetic flux can be linked to the stator winding. Further, if the flange portion 38 is provided, the armature winding 32 can be reliably held between the substrate 31 and the flange portion 38. Here, the teeth 34 and the collar part 38 are integrally formed.

  In the present embodiment, a concentrated winding method in which one armature winding 32 is wound around one tooth 34 is employed. By adopting the concentrated winding method, the winding length can be shortened, so that the copper loss can be suppressed and the length of the teeth 34 in the direction of the rotating shaft 90 can be shortened. Note that a distributed winding method in which one armature winding 32 is wound across a plurality of teeth 34 may be employed.

  In the present application, unless otherwise specified, the armature winding 32 does not indicate each of the conductive wires constituting the armature winding 32 but indicates an aspect in which the conductive wires are wound together. The same applies to the drawings. In addition, the winding start and winding lead lines and their connections are also omitted in the drawings.

  3A and 3B, the annular region 40 in which the magnetic pole surface 22 and the teeth 34 face each other in the direction of the rotation shaft 90 is a magnetic pole surface centered on the rotation shaft 90. The ratio between the circumferential lengths LR1 and LR2 of 22 and the circumferential lengths LS1 and LS2 of the teeth 34 does not depend on the radial position around the rotation shaft 90, and a predetermined width | R1- Including an annulus having R2 |.

  Specifically, as shown in FIG. 4, in the annular region 40, the length LR <b> 1 where the outer diameter of the region 40 and the magnetic pole surface 22 overlap in the direction of the rotating shaft 90, the outer diameter, and the teeth 34. The length LS1 that overlaps in the direction of the rotating shaft 90 is the length LR2 in which the inner diameter of the region 40 and the magnetic pole surface 22 overlap in the direction of the rotating shaft 90, and the inner diameter and the tooth 34 rotate in the rotating shaft 90. It is equal to the ratio with the length LS2 overlapping in the direction of. This is true regardless of the sizes of the radii R1 and R2. In other words, the magnetic pole face 22 and the teeth 34 are formed so as to satisfy the above ratio. Here, the magnetic pole surface 22 and the tooth 34 shown in FIG. 4 are actually hidden by the back yoke 21 and should be indicated by broken lines. However, in order to clarify the identification of each element, a part of the magnetic pole surface 22 and the teeth 34 are solid lines. Is shown.

  From the viewpoint of efficiently carrying out the present invention, the ideal shape of the magnetic pole surface 22 and the tooth 34 is as described above over the entire region where the magnetic pole surface 22 and the tooth 34 overlap in the direction of the rotating shaft 90. It is desirable to satisfy such a ratio. However, in actuality, in order to efficiently and easily wind the armature winding 32, or in consideration of convenience in the manufacturing process, each corner is chamfered in the radial direction or curved. Often, a fillet is provided. Therefore, the above ratio is satisfied for the areas excluding the areas to be processed. In the present embodiment, the tooth 34 has a columnar shape in which the cross section in the direction of the rotation axis 90 is substantially arched, but is not limited thereto.

<Planar shape of reluctan score>
The axial gap type motor 10 according to the present embodiment supplies the U-phase current, the V-phase current, and the W-phase current to the armature winding 32, so that the magnetic flux flowing out from the upper surface 38 </ b> S of the flange portion 38, or the upper surface The magnetic flux flowing into 38S is generated, and the magnetic flux acts on the rotor 20 to rotate the rotor 20 around the rotation shaft 90. Here, in the axial gap type motor 10, the magnetic flux flowing into one reluctance score 28 </ b> A bypasses the permanent magnet 23, passes through the back yoke 21, and flows out from the other reluctance score 28 </ b> A to generate reluctance torque. . Therefore, in order to increase the reluctance torque in the axial gap motor 10, it is only necessary to increase the occupation area of the reluctance score 28A, secure a magnetic path that contributes to the generation of the reluctance torque, and increase the q-axis inductance.

  In the present invention, the plurality of teeth 34 adjacent in the circumferential direction have substantially parallel sides facing each other in the circumferential direction. That is, each tooth 34 is formed in a substantially arched shape or a substantially trapezoidal shape.

  Therefore, in the axial gap type motor 10 of the present embodiment, the reluctance score 28A is formed over substantially the entire area of the rotor 20 excluding the region where the plurality of permanent magnets 23 formed in a substantially arch shape are disposed. As a result, the occupied area of the reluctance score 28A can be widened to increase the reluctance torque and thus the total torque.

  Furthermore, when the second magnetic body 29 is unevenly distributed on the inner peripheral side of the rotor 20, the magnetic path of the magnetic flux contributing to the generation of the reluctance torque is closer to the inner peripheral side than the magnetic path of the magnetic flux contributing to the generation of the magnet torque. Both can be separated. Thereby, the magnetic saturation of the back yoke 21 can be suppressed, and problems caused by the magnetic saturation of the back yoke 21 such as a decrease in d-axis inductance and a decrease in q-axis inductance can be suppressed.

  The reluctan score 28A is an inner peripheral portion (magnetic body 29) and also serves as a part of the fastening hole 25 fastened to the shaft disposed along the rotation shaft 90. Therefore, the fastening force between the rotor 20 and the shaft. Increases, and the inclination of the rotor 20 can be suppressed or avoided.

<Effects of First Embodiment>
As described above, according to the invention of the present embodiment, the annular region 40 where the magnetic pole surface 22 and the tooth 34 face each other in the direction of the rotating shaft 90 is a circumferential length around the rotating shaft 90 of the magnetic pole surface 22. The ratio between the lengths LR1 and LR2 and the circumferential lengths LS1 and LS2 of the teeth 34 does not depend on the position in the radial direction around the rotating shaft 90, and has a predetermined width | R2-R1 | Since the ring is included, the region where the magnetic flux density is uniform increases. In particular, the radial component of the magnetic flux can be reduced on the inner peripheral side of the tooth 34, and magnetic saturation can be avoided or suppressed. Moreover, iron loss can be reduced.

  Moreover, since the teeth 34 are configured by laminating the thin plate 36 extending in the circumferential direction or the thin plate 37 extending in the direction orthogonal to the radial direction in the radial direction, the radial component of the magnetic flux can be reduced.

  In addition, since the teeth 34 and the permanent magnets 23 directly face each other through a predetermined gap, the magnetic flux density inside the teeth 34 can be made more uniform.

  Since a plurality of teeth 34 adjacent in the circumferential direction have substantially parallel sides facing each other in the circumferential direction, the space between the teeth 34 in which the armature windings 32 are accommodated is constant in the radial direction. Increases the space factor.

  Further, since the rotor 20 further includes the first magnetic body 28 between the adjacent magnetic pole faces 22, the magnetic body 28 can increase the so-called q-axis inductance and contribute to a motor that uses reluctance torque.

  Further, since the reluctance score 28A is unevenly distributed on the inner peripheral side with respect to the outermost outer periphery of the magnetic pole surface 22, the portion where the permanent magnet 23 is not provided can be used effectively, and the q-axis inductance can be increased. Furthermore, the rapid alternating of the magnetic poles of the rotor 20 can be mitigated.

  Furthermore, since the first magnetic body 28 is further provided with the second magnetic body 29 that is connected to each other on the radially inner peripheral side, the q-axis inductance can be increased. Further, even when the back yoke 21 is provided on the rotor 20, the magnetic path for generating the magnet torque and the magnetic path for generating the reluctance torque can be separated, so that the magnetic saturation of the back yoke 21 can be avoided or suppressed.

Second Embodiment
In the first embodiment, the aspect in which the magnetic pole surface 22 and the tooth 34 directly face each other has been described, but the present invention is not limited to this. Here, the aspect which applies the rotor magnetic core 24a as 2nd Embodiment of this invention is demonstrated, referring drawings. In the following description of the embodiment, unless otherwise specified, elements having the same functions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 5 is an exploded perspective view of the axial gap type motor 10 a according to the second embodiment of the present invention, which is disassembled along the rotating shaft 90. FIG. 6 is an enlarged view of the rotor magnetic cores 24a and 24d. In this embodiment, the case of 8 poles and 12 slots will be described as an example.

  As shown in FIG. 5, the rotor 20a of the axial gap type motor 10a includes a back yoke 21, a permanent magnet 23, and a rotor magnetic core 24a having a magnetic pole surface 22a on the side of the permanent magnet 23 facing the teeth 34. Have. Specifically, a rotor magnetic core 24 a formed in substantially the same shape as the permanent magnet 23 is disposed on one surface of the permanent magnet 23 facing the stator 30 by, for example, bonding.

  As shown in FIG. 6A, the rotor magnetic core 24 a is configured by laminating thin plates 26 extending in the circumferential direction with respect to the rotation shaft 90 in the radial direction from the rotation shaft 90. Alternatively, as shown in FIG. 6B, the rotor magnetic core 24d is configured by laminating thin plates 27 extending in a direction orthogonal to the radial direction in the radial direction. In this embodiment, the mode shown in FIG. 6A is adopted. The rotor magnetic core 24a is formed of a soft magnetic material, and the surface facing the stator 30 among the surfaces having the rotor magnetic core 24a rotating shaft 90 as a normal line is the magnetic pole surface 22a of the rotor 20a.

<Effects of Second Embodiment>
As described above, according to the invention of the present embodiment, the rotor 20a includes the permanent magnet 23 and the rotor magnetic core 24a that exhibits the magnetic pole surface 22a on the side of the permanent magnet 23 that faces the teeth 34. Even when a large current flows through 30, the demagnetizing field does not directly act on the permanent magnet 23, so that the permanent magnet 23 is difficult to demagnetize. Therefore, when the permanent magnet 23 is composed of a neodymium sintered magnet having a low resistivity, loss and heat generation due to eddy current generated inside the permanent magnet 23 can be avoided or suppressed. In other words, since the demagnetizing field is relaxed by the rotor core 24a, the axial gap motor 10a that is strong against demagnetization can be provided. Further, since a high coercive force is not required, a permanent magnet 23 having a high magnetic flux density can be used.

  Further, the rotor magnetic core 24a is configured by laminating the thin plate 26 extending in the circumferential direction or the thin plate 27 extending in the direction orthogonal to the radial direction in the radial direction. The magnetic flux moving in the direction can be reduced, the magnetic flux density can be made uniform, and the magnetic resistance can be reduced. Moreover, iron loss can be reduced.

<Third Embodiment>
In the said 2nd Embodiment, although the rotor magnetic core 24a demonstrated the aspect arrange | positioned separately in each of the some permanent magnet 23, this invention is not limited to this. Here, as a third embodiment of the present invention, an aspect in which the rotor magnetic core 24b is integrally formed will be described with reference to the drawings.

  FIG. 7 is an exploded perspective view of the axial gap type motor 10 b according to the third embodiment of the present invention, which is disassembled along the rotating shaft 90. In this embodiment, the case of 8 poles and 12 slots will be described as an example.

  As shown in FIG. 7, for example, an annular magnetic body 50b having substantially the same size as the ring formed by the outer circumference and the inner circumference of a substantially arch-shaped permanent magnet 23 annularly arranged on the back yoke 21 has a rotational axis. The number of radial slits 52b centering on 90 is the same as the number of poles (eight in this embodiment). The slit 52b equally divides the annular magnetic body 50b, and a thin portion 54b is formed at the end in the radial direction. The region between the two slits 52b functions as the rotor magnetic core 24b by being disposed so as to overlap the permanent magnet 23, and this region becomes the magnetic pole surface 22b of the rotor 20b. Here, the adjacent rotor cores 24b, that is, the magnetic pole surfaces 22b are connected to each other by the thin-walled portion 54b, but the magnetic pole surfaces 22b are not magnetically short-circuited because they are easily magnetically saturated.

  The rotor 20b of this embodiment is not provided with the reluctance score 28A shown in the above embodiment, but the reluctan score 28A can be provided even if the rotor magnetic core 24b is formed integrally. Further, it is possible to integrally form the rotor magnetic core 24b and the reluctance score 28A.

<Effect of the third embodiment>
Thus, by integrally forming the rotor magnetic core 24b, the attachment to the permanent magnet 23 can be easily performed.

<First Modification>
In the first to third embodiments, the aspect in which the magnetic pole surfaces 22, 22a, 22b and the teeth 34 are each formed in a substantially arch shape has been described, but the present invention is not limited to this. Here, as a modification of the first embodiment of the present invention, an aspect in which both are formed in a substantially trapezoidal shape in a plane perpendicular to the rotation shaft 90 will be described with reference to the drawings.

  FIG. 8 is an exploded perspective view of the axial gap type motor 10 c according to the first modified example of the present invention, which is disassembled along the rotating shaft 90. FIG. 9 is a perspective plan view of the axial gap type motor 10c as seen from the direction of the rotation axis 90. FIG.

  As shown in FIGS. 8 and 9, in the rotor 20c of the axial gap type motor 10c, the upper surface of the permanent magnet 23c arranged in an annular shape on one surface of the back yoke 21 presents the magnetic pole surface 22c. And this magnetic pole surface 22c is formed in the substantially trapezoid shape. Specifically, the magnetic pole surface 22c has a shape in which the portion forming the arch at both ends in the radial direction in the magnetic pole surface 22 of the first embodiment is replaced with a straight line extending in a direction perpendicular to the radial direction. Presents. Further, the teeth 34 apply the shape described in FIG. 3B of the first embodiment. Here, the magnetic pole surface 22c is arranged with alternating magnetic poles in the circumferential direction. Further, the magnetic pole surface 22c and the tooth 34 shown in FIG. 9 are actually hidden by the back yoke 21 and should be indicated by broken lines, but in order to clarify the identification of each element, a part is indicated by a solid line. Show.

  As described above, when the magnetic pole surface 22c and the cross-sectional shape of the tooth 34 are each formed in a substantially trapezoidal shape, the circumferential lengths LR1 and LR2 of the magnetic pole surface 22c at the radii R1 and R2, and the radii R1 and R2 The circumferential lengths LS1 and LS2 of the teeth 34 in FIG. 3 are the tangential magnetic pole surfaces 22c or the teeth 34 when they are in contact with a virtual circle with the radius R1 or the radius R2 at the center of the line segments indicating the respective lengths. Or the length of the magnetic pole surface 22c or the teeth 34 in the tangential direction when the end of the line segment is in contact with the virtual circle.

  Thus, the present invention can be implemented even when the magnetic pole surface 22c and the cross-sectional shape of the tooth 34 are each formed in a substantially trapezoidal shape. Therefore, they can be manufactured more easily than forming them in a substantially arch shape.

<Second Modification>
FIG. 10 is an exploded perspective view of the axial gap type motor 10d according to the second modification of the present invention, and is exploded along the direction of the rotating shaft 90. FIG. As shown in FIG. 10, as a further modification of the present invention, the rotor 20d may be configured as follows as a mode in which the second embodiment and the first modification are combined. That is, on one surface of the back yoke 21d, the permanent magnets 23d having a substantially trapezoidal cross section are arranged in an annular shape with alternating magnetic poles. A rotor magnetic core 24 d formed in substantially the same shape is disposed, and the upper surface of the rotor magnetic core 24 d is used as a magnetic pole surface 22 d of the rotor 20.

  As described above, the magnetic pole face 22d and the cross-sectional shape of the teeth 34 are each formed in a substantially trapezoidal shape, and the rotor magnetic core 24d is adopted, so that the manufacturing process is simple and the axial gap motor 10d is strong against demagnetization. Can provide.

<Third Modification>
FIG. 11 is an exploded perspective view of an axial gap type motor 10e according to a third modification of the present invention, which is disassembled along the direction of the rotating shaft 90. FIG. As shown in FIG. 11, as a further modification of the present invention, two stators 30 are arranged so that the surfaces on which the teeth 34 of the respective stators 30 are disposed are opposed to each other, and both stators are arranged. A mode is also possible in which the rotor 20e is disposed between 30 through a predetermined gap.

  The rotor 20e of the present modification does not use elements corresponding to the back yoke 21 shown in the above embodiment, and includes a permanent magnet 23c, a rotor magnetic core 24d, and a reluctance score 28Ae, and an inner circumference of the reluctance score 28Ae. A shaft (not shown) disposed along the direction of the rotating shaft 90 is fitted and fixed.

  The rotor magnetic core 24d is disposed on each of both end surfaces with the rotation axis 90 of the permanent magnet 23c as a normal line, and the permanent magnet 23c and the rotor magnetic core 24d are joined by, for example, adhesion. That is, in the present embodiment, both end surfaces of the two rotor magnetic cores 24d joined via the permanent magnet 23c exhibit the magnetic pole surface 22e.

  Further, the permanent magnet 23c and the rotor magnetic core 24d are connected to the reluctance score 28Ae by a thin portion (not shown) that is easily magnetically saturated. That is, the permanent magnet 23e, the rotor magnetic core 24d, and the reluctance score 28Ae are connected in a state of being kept magnetically independent.

  The permanent magnet 23c, the rotor magnetic core 24d, and the reluctance score 28Ae may be held by a nonmagnetic holder including a resin molded holder or the like. The length of the reluctance score 28Ae in the direction of the rotation axis 90 is substantially equal to the length in the direction of the rotation axis 90 when the permanent magnet 23c is sandwiched between the two rotor magnetic cores 24d.

  In the case of such an aspect, since the load on the bearing is offset by the air gaps (air gaps) provided on both sides of the rotor 20e, the mechanical loss can be reduced.

1 is an exploded perspective view of an axial gap motor according to a first embodiment of the present invention. It is the perspective view which looked at the rotor diagonally from the armature side. It is an enlarged view of the teeth which a stator has. It is the plane perspective view which looked at the axial gap type motor from the direction of a rotation axis. It is a disassembled perspective view of the axial gap type motor which concerns on 2nd Embodiment of this invention. It is an enlarged view of a rotor magnetic core. It is a disassembled perspective view of the axial gap type motor which concerns on 3rd Embodiment of this invention. It is a disassembled perspective view of the axial gap type motor which concerns on the 1st modification of this invention. It is the plane perspective view which looked at the axial gap type motor from the direction of a rotation axis. It is a disassembled perspective view of the axial gap type motor which concerns on the 2nd modification of this invention. It is a disassembled perspective view of the axial gap type motor which concerns on the 3rd modification of this invention.

Explanation of symbols

10, 10a to 10e Axial gap type motor 20, 20a to 20e Rotor 22, 22a to 22e Magnetic pole surface 23, 23c Permanent magnet 24, 24a, 24b, 24d Rotor core 26 Thin plate 27 Thin plate 28 First magnetic body 29 Second magnetic material Body 30 Stator 32 Armature winding 34 Teeth 36 Thin plate 37 Thin plate 40 Region 90 Rotating shaft LR1, LR2 Circumferential length LS1, LS2 Circumferential length R1, R2 Radius

Claims (11)

A rotor (20, 20a to 20e) having a plurality of magnetic pole faces (22, 22a to 22e) arranged in an annular manner around the rotation axis (90) and alternating magnetic poles;
A tooth (34) for holding a plurality of armature windings (32) arranged in an annular shape around the rotation axis, and along the direction of the rotation axis via the rotor and a predetermined gap; An axial gap type motor (10, 10a to 10e) comprising an opposing stator (30),
An annular region (40) in which the magnetic pole surface and the teeth face each other in the direction of the rotation axis,
The ratio of the circumferential length (LR1, LR2) of the magnetic pole surface around the rotation axis and the circumferential length of the teeth (LS1, LS2) is at a radial position around the rotation axis. An axial gap type motor including an annulus having a predetermined width (| R2-R1 |) in the radial direction without depending on it. An axial gap type motor (10, 10a to 10e) according to claim 1,
The tooth (34) is an axial gap type motor configured by laminating thin plates (36) extending in the circumferential direction in the radial direction. An axial gap type motor (10, 10a to 10e) according to claim 1,
The tooth (34) is an axial gap type motor configured by laminating thin plates (37) extending in a direction perpendicular to the radial direction in the radial direction. An axial gap type motor (10, 10c) according to any one of claims 1 to 3,
The rotor (20, 20c) has a permanent magnet (23, 23c) having the magnetic pole surface (22, 22c) as a surface,
An axial gap type motor in which the teeth (34) and the permanent magnets are directly opposed to each other through the gap. An axial gap type motor (10a, 10b, 10d, 10e) according to any one of claims 1 to 3,
The rotor (20a, 20b, 20d, 20e) includes the permanent magnet (23a, 23c) and the magnetic pole surface (22a, 22b, 22d, 22e) on the side of the permanent magnet facing the teeth (34). An axial gap type motor further comprising a rotor magnetic core (24a, 24b, 24d) exhibiting the following. An axial gap type motor (10a, 10b, 10d, 10e) according to claim 5,
The rotor magnetic core (24a, 24b, 24d) is an axial gap type motor configured by laminating thin plates (26) extending in the circumferential direction in the radial direction. An axial gap type motor (10a, 10b, 10d, 10e) according to claim 5,
The rotor magnetic core (24a, 24b, 24d) is an axial gap type motor configured by laminating thin plates (27) extending in a direction perpendicular to the radial direction in the radial direction. An axial gap type motor (10, 10a to 10e) according to any one of claims 1 to 7,
The plurality of teeth (34) adjacent in the circumferential direction is an axial gap type motor in which sides facing each other in the circumferential direction are substantially parallel to each other. An axial gap type motor (10, 10a, 10c to 10e) according to claim 4 or 5,
The rotor (20, 20a, 20c to 20e) is an axial gap type motor further including a first magnetic body (28) between the adjacent magnetic pole surfaces (22, 22a, 22c to 22e). An axial gap type motor (10, 10a, 10c to 10e) according to claim 9,
The first magnetic body (28) is an axial gap type motor in which the first magnetic body (28) is unevenly distributed on the inner peripheral side with respect to the outermost outer periphery of the magnetic pole surface (22, 22a, 22c to 22e). An axial gap type motor (10, 10a, 10c to 10e) according to claim 9 or 10,
An axial gap type motor further comprising a second magnetic body (29) that connects the first magnetic bodies (28) to each other on the inner peripheral side in the radial direction.

Images