JP6260995B2 - Axial gap type motor - Google Patents

Description

  The present invention relates to an axial gap type motor, and more particularly to a technology for supplying the field magnetic flux.

  As a field magnetic flux supply source in a motor, a technique using a permanent magnet and a field winding in combination is known. A field magnetic flux whose strength is variable depending on the current flowing through the field winding (hereinafter referred to as “sub-field magnetic flux”) is supplied by a permanent magnet (unless the demagnetization effect is taken into consideration). Acts as a so-called field weakening or field strengthening with respect to a fixed field magnetic flux (hereinafter referred to as “main field magnetic flux”).

  By adopting the subfield magnetic flux together with the main field magnetic flux, it is possible to operate efficiently in a wider operating range (for example, a range of torque and rotational speed) compared to the case where the subfield magnetic flux is not employed.

JP 2006-141106 A JP 2008-043099 A JP 2008-187826 A JP2012-157182A JP 2012-182944 A JP 2012-182945 A

Kosaka, Matsui, “Possibility of rare-earth rare-earth magnet hybrid field motor for HEV application”, 2010 IEEJ Industrial Application Conference, 2-S8-4, p. II-81-II-86, 2010

  On the other hand, depending on the use of the motor, for example, a motor that is flat in the direction of the rotation axis may be desired as an in-wheel motor. From such a viewpoint, an axial gap type motor in which an armature as a stator and a field element as a rotor face each other in the direction of the rotation axis is suitable.

  In such an axial gap type motor, since magnetic flux flows between the stator and the rotor in the axial direction, axial thrust force is generated in the rotor. The rotor moves or vibrates in the axial direction by the thrust force.

  Therefore, an object of the present invention is to provide an axial gap type motor that can suppress movement (or vibration) of the rotor in the axial direction.

  A first aspect of an axial gap type motor according to the present invention includes a magnet magnetic pole portion (31) including a permanent magnet that rotates around a predetermined rotation axis (P), a soft magnetic body (32), and the magnet. A magnetic pole part and a soft magnetic outer member (33) provided on the outer peripheral side of the soft magnetic body, the magnet magnetic pole part and the soft magnetic body are alternately arranged in a circumferential direction with respect to the rotation axis, All of the magnet magnetic pole portions (31) have the same polarity surface of the first polarity on both sides of the rotating shaft, and the second polarity of the magnetic pole is different from the first polarity toward the outside in the radial direction of the rotating shaft. A plurality of first protrusions (334) that are provided side by side along the axial direction along the rotation axis and project outward in the radial direction are formed on the outer peripheral surface of the outer member. From the rotor (3) and one side of the rotating shaft The first armature winding (13), the plurality of first teeth (11) around which the first armature winding is wound, the rotor on the opposite side of the rotor, A first stator (1) having a first back yoke (12) for magnetically short-circuiting the first teeth of the first tooth, and the second armature winding ( 23), a plurality of second teeth (21) around which the second armature winding is wound, and a second back yoke for magnetically short-circuiting the plurality of second teeth on the side opposite to the rotor A second stator (2) having (22), and arranged around the rotation axis between the first back yoke and the rotor, and generates a magnetic field in a first direction along the rotation axis. The rotary shaft between the first field winding (41) and the second back yoke and the rotor. A second field winding (42) disposed around and generating a magnetic field in a direction opposite to the first direction, each of the first back yoke and the second back yoke, and magnetically on the outer edge side thereof. The plurality of second protrusions (361) projecting inward in the radial direction and opposed to the outer member via a gap are arranged at the same pitch as the plurality of first protrusions. A short-circuiting ring (36) provided side by side along the direction.

  A second aspect of the axial gap type motor according to the present invention is the axial gap type motor according to the first aspect, wherein at least one of the outer member (33) and the short-circuiting ring (36) is: It is formed by electromagnetic steel plates laminated in the axial direction.

  A third aspect of the axial gap type motor according to the present invention is the axial gap type motor according to the second aspect, wherein the first protrusion (334) and the second protrusion (361), The thickness in the axial direction of the protrusions belonging to at least one of the outer member (33) and the short-circuiting ring (36) is an integral multiple of the thickness of the electromagnetic steel sheet.

  A fourth aspect of the axial gap type motor according to the present invention is the axial gap type motor according to any one of the first to third aspects, wherein the magnet magnetic pole portion ( A non-magnetic material (335) is formed in a portion corresponding to between 31) and the soft magnetic material (32).

  A fifth aspect of the axial gap type motor according to the present invention is the axial gap type motor according to any one of the first to fourth aspects, wherein the first stator (1) includes the short-circuit ring. (36) and a first ring (14) for magnetically short-circuiting the first back yoke (12), and the second stator (2) includes the short-circuiting ring (36) and the first back yoke (12). Further, a second ring (24) for magnetically short-circuiting the two back yokes (22) is further provided, and the first ring or the second ring is an iron core in which an electromagnetic steel sheet is wound around the rotation axis.

  A sixth aspect of the axial gap type motor according to the present invention is the axial gap type motor according to any one of the first to fifth aspects, wherein each of the magnet magnetic pole portions (32) is a second soft gap type motor. It has a magnetic body (317) and a first permanent magnet (316) that is positioned on the outer peripheral side of the second soft magnetic body and is magnetized in the radial direction.

  A seventh aspect of the axial gap type motor according to the present invention is the axial gap type motor according to the sixth aspect, wherein each of the magnet magnetic pole portions (31) is connected to the second soft magnetic body (317). On the other hand, a second permanent magnet (314) adjacent from one side in the circumferential direction and a third permanent magnet (314) adjacent from the other side in the circumferential direction with respect to the second soft magnetic body are further provided. And the second and third permanent magnets are arranged with a magnetic pole face having the same polarity as the magnetic pole face directed to the second soft magnetic body by the first permanent magnet facing the second soft magnetic body. .

  An eighth aspect of the axial gap type motor according to the present invention is the axial gap type motor according to any one of the first to fifth aspects, wherein each of the magnetic pole portions includes a second soft magnetic material ( 313), a first permanent magnet (311) positioned closer to the first stator (1) than the second soft magnetic body, and the second stator (2) side relative to the second soft magnetic body And the second permanent magnet has a magnetic pole surface having the same polarity as the magnetic pole surface toward which the first permanent magnet faces the second soft magnetic body. It is arranged toward the magnetic body.

  A ninth aspect of the axial gap type motor according to the present invention is the axial gap type motor according to any one of the first to eighth aspects, wherein the first protrusions (334) are connected to each other and the first Resin is provided in at least one of the two protrusions (361).

  A tenth aspect of the axial gap type motor according to the present invention is the axial gap type motor according to any one of the first to ninth aspects, wherein the outer member (33) and the short-circuit ring (36). The radial distance between the rotor and the rotor (3) is smaller than the air gap between the first stator (1) or the second stator (2).

  According to the first aspect of the axial gap type motor of the present invention, since the magnetic flux flows between the outer member and the short-circuiting ring, when the rotor moves to one side in the axial direction with respect to the protrusion, it rotates. A force directed toward the other side in the axial direction acts on the child. Moreover, the magnetic flux flows between the plurality of first protrusions and the plurality of second protrusions. Thereby, as shown by embodiment, the force of the other side of an axial direction can be increased, and the movement in the axial direction of a rotor can be suppressed.

  According to the second aspect of the axial gap type motor of the present invention, the eddy current generated due to the main field magnetic flux or the subfield magnetic flux can be reduced.

  According to the third aspect of the axial gap type motor of the present invention, manufacture is easy.

  According to the 4th aspect of the axial gap type motor concerning this invention, it is easy to flow the magnetic flux which flows from a magnetic pole part to an outer member to a short circuit ring rather than a soft magnetic body. Therefore, the magnetic flux between the outer member and the short-circuiting ring can be increased, and as a result, the force (the axial force on the other side) generated in the rotor due to the magnetic flux can be increased. Therefore, the movement of the rotor can be further suppressed.

  According to the fifth aspect of the axial gap type motor of the present invention, since the iron core wound with the electromagnetic steel sheet has a small magnetic resistance in the axial direction, each of the first and second back yokes, the protrusion, Suitable for magnetic short circuit.

  According to the sixth aspect of the axial gap type motor of the present invention, the magnetic flux from the first permanent magnet flows between the rotor and the protrusion. Therefore, the force (force on the other side in the axial direction) generated in the rotor increases.

  According to the seventh aspect of the axial gap type motor of the present invention, the second and third permanent magnets contribute to the magnetization of the soft magnetic material.

  According to the eighth aspect of the axial gap motor of the present invention, the magnetic pole portion can be configured with a relatively simple configuration.

  According to the ninth aspect of the axial gap type motor of the present invention, the strength of the rotor or the short-circuiting ring can be improved.

  According to the tenth aspect of the axial gap type motor of the present invention, since the magnetic resistance between the rotor and the protrusion can be reduced, the magnetic flux between the rotor and the protrusion can be increased. The force (force on the other side) generated in the rotor due to the magnetic flux can be increased. Therefore, the movement of the rotor can be further suppressed.

It is a perspective view which shows the structure of the axial gap type motor concerning 1st Embodiment. It is a perspective view which shows a part of structure of a field element. It is a perspective view which shows a part of structure of a holding body. It is sectional drawing which illustrates the structure of the axial gap type motor concerning 1st Embodiment. It is the figure which expanded the cross section of the field element. It is sectional drawing which shows notionally a field element and the ring for a short circuit. It is sectional drawing which shows notionally a field element and the ring for a short circuit. It is sectional drawing which shows notionally a field element and the ring for a short circuit. It is sectional drawing which shows notionally a field element and the ring for a short circuit. It is sectional drawing which shows notionally a field element and the ring for a short circuit. It is sectional drawing which shows notionally a field element and the ring for a short circuit. It is sectional drawing which shows notionally a field element and the ring for a short circuit. It is a graph which shows the force which acts on a field element. It is a perspective view which shows a part of structure of the field element concerning 2nd Embodiment. It is sectional drawing which illustrates the structure of the axial gap type motor concerning 2nd Embodiment. It is the figure which expanded the cross section of the field element. It is a perspective view which shows the structure of the field element of the axial gap type motor concerning 3rd Embodiment.

First embodiment.
FIG. 1 is a perspective view conceptually showing the configuration of the axial gap motor according to the first embodiment. In order to facilitate understanding of the structure, the motor is shown exploded along the rotation axis P. However, a person having ordinary technical knowledge in the field of motors can recognize the structure of the axial gap type motor from FIG.

  The axial gap type motor includes armatures 1 and 2 that are stators, a field element 3 that is a rotor, field windings 41 and 42, and a short-circuiting ring 36. The field element 3 is rotated around the rotation axis P by the rotating magnetic field supplied by the armatures 1 and 2, the main field magnetic flux, and the subfield magnetic flux.

  The armature 1 is from one side (upper side in FIG. 1) of the rotating shaft P to the field element 3, and the armature 2 is from the other side (lower side in FIG. 1) to the field element 3, so-called air. Opposing with a gap called a gap.

  The field element 3 includes a holding body 30, a magnet magnetic pole portion 31 having a permanent magnet, and a soft magnetic body 32. The magnet magnetic pole portion 31 supplies a main field magnetic flux whose size is constant if demagnetization is not considered.

  The magnet magnetic pole portions 31 and the soft magnetic bodies 32 are alternately arranged in the circumferential direction with respect to the rotation axis P. In this embodiment, a case where ten magnet magnetic pole portions 31 and ten soft magnetic bodies 32 are provided is illustrated.

  The holding body 30 is, for example, soft magnetic and includes an outer ring 33 (corresponding to an outer member), an inner ring 34, and a partition wall 35. The partition wall 35 is located between the magnetic pole portion 31 and the soft magnetic body 32 and holds them in the circumferential direction. The outer ring 33 holds the magnet magnetic pole portion 31 and the soft magnetic body 32 from the outside in the radial direction of the rotation axis P, and the inner ring 34 holds from the inside in the radial direction of the rotation axis P, respectively.

  FIG. 2 is a perspective view showing a part of a more detailed configuration of the field element 3. Here, in order to make the said structure easy to visually recognize, the part extended at 180 degrees in the circumferential direction was removed and shown. In FIG. 2, the cross section of the magnetic pole part 31 appears. FIG. 3 is a diagram in which the magnetic pole portion 31 and the soft magnetic body 32 are omitted from the field element 3 of FIG. FIG. 3 can also be grasped as a perspective view showing a part of the holding body 30.

  FIG. 4 is a cross-sectional view illustrating the configuration of the axial gap motor. The cross section includes the rotation axis P, is a plane parallel to the rotation axis P, and is in a position where the magnet magnetic pole portion 31 appears.

  On one side of the rotation axis P, all of the magnetic pole portions 31 exhibit the same magnetic pole surface with the same first polarity (N pole in FIG. 2). Also, on the other side of the rotation axis P, all of the magnetic pole portions 31 exhibit the same magnetic pole surface having the first polarity. Moreover, the magnet magnetic pole part 31 exhibits the magnetic pole surface of the 2nd polarity (for example, S pole) different from a 1st polarity toward radial direction outer side. For example, each of the magnetic pole portions 31 includes permanent magnets 311 and 312 and a soft magnetic body 313. Each of the permanent magnets 311 and 312 and the soft magnetic body 313 has a flat plate shape and is arranged so as to overlap each other in the axial direction. The soft magnetic body 313 is located between the permanent magnets 311 and 312 in the axial direction. Each of the permanent magnets 311 and 312 is magnetized in the axial direction, and is disposed toward the soft magnetic body 313 with the magnetic pole surfaces of the same second polarity (for example, S pole) facing each other.

  In the example of FIG. 3, each of the partition walls 35 includes an upper partition wall 351, a lower partition wall 352, and an intermediate partition wall 353. The upper partition wall 351 and the lower partition wall 352 are separated from each other in the axial direction, are formed integrally with the inner ring 34, and extend in the radial direction. The middle partition 353 is provided between the upper partition 351 and the lower partition 352 and extends in the radial direction.

  In the illustration of FIG. 3, the outer ring 33 includes an upper outer ring 331, a lower outer ring 332, and a main outer ring 333. The upper and outer rings 331 are formed integrally with each of the upper partition walls 351 on the side opposite to the inner ring 34. The upper outer ring 331 connects the upper partition 351 in the circumferential direction. The lower outer ring 332 is formed integrally with each of the lower partition walls 352 on the side opposite to the inner ring 34. The lower outer ring 332 connects the lower partition 352 in the circumferential direction. The main outer ring 333 protrudes from the upper outer ring 331 and the lower outer ring 332 to the outer peripheral side, and is adjacent to the soft magnetic body 313 in the radial direction (see also FIG. 2).

  The inner ring 34, the upper partition 351, the lower partition 352, the upper outer ring 331, and the lower outer ring 332 may be formed of any material, but are formed of a relatively strong material (for example, stainless steel). Good. Thereby, the strength of the field element 3 can be improved. In this case, the inner ring 34 may be separated into two in the axial direction. As a result, the first outer member of the inner ring 34, the upper partition 351 and the upper outer ring 331, the lower member of the inner ring 34, the second member of the lower partition 352 and the lower outer ring 332, the main outer ring The holding body 30 can be assembled by sandwiching a part of 333 in the axial direction.

  The middle partition 353 is adjacent to the soft magnetic body 313 in the circumferential direction, and a part of the main field magnetic flux φm flows through the middle partition 353 as will be described in detail later (FIG. 5). Therefore, it is desirable that the middle partition 353 be formed of a soft magnetic material. Thereby, the main field magnetic flux φm can be increased as compared with the case where the middle partition 353 is formed of a nonmagnetic material. Further, the intermediate partition 353 may be formed by, for example, electromagnetic steel plates laminated in the axial direction or the radial direction. Thereby, generation | occurrence | production of the eddy current resulting from the main field magnetic flux (phi) m can be reduced.

  The main outer ring 333 is formed of a soft magnetic material. For example, the main outer ring 333 is formed by electromagnetic steel plates laminated in the axial direction. As will be described later in detail, another part of the main field magnetic flux φm and the sub-field magnetic flux φa flow in the main outer ring 333 (FIG. 4). However, the main outer ring 333 is formed of a magnetic steel sheet. Thus, the generation of eddy currents caused by at least one of the main field magnetic flux φm and the subfield magnetic flux φa can be reduced.

  A plurality of protrusions 334 are formed on the outer peripheral surface of the main outer ring 333. The plurality of protrusions 334 are provided at intervals along the axial direction, and protrude to the radially outer peripheral side. 2 to 4, the three protrusions 334 are provided, and each of them is continuous over the entire circumference.

  When the main outer ring 333 is formed of an electromagnetic steel plate along the axial direction, the width in the axial direction of the protrusions 334 and the interval in the axial direction between the protrusions 334 are one electromagnetic steel plate. It is desirable that it is an integral multiple of the per-thickness. Thus, it is not necessary to cut the magnetic steel sheet in the thickness direction for forming the protrusions 334, and by simply stacking the electromagnetic steel sheets having a large diameter and the electromagnetic steel sheets having a small diameter, the protrusions 334 and the protrusions 334 can be connected to each other. Can be formed. Therefore, manufacture is easy.

  A rotating shaft is inserted into the inner ring 34 and fixed. 1 to 4, the rotating shaft is omitted. The rotating shaft rotates with the rotation of the field element 3.

  The armature 1 includes a tooth 11, a back yoke 12, and an armature winding 13. A plurality of teeth 11 are provided in a ring shape. An armature winding 13 is wound around the teeth 11. The back yoke 12 magnetically shorts the teeth 11 on the side opposite to the field element 3.

  For example, the teeth 11 have a bottom portion penetrating the back yoke 12, and the bottom portion appears in FIG.

  The back yoke 12 has a hole 10 at a position facing the inner ring 34 on the rotation axis P. A rotating shaft (not shown) is rotatably inserted in the hole 10. An alternating current flows through the armature winding 13 and supplies a rotating magnetic field to the field element 3.

  The armature 2 includes a tooth 21, a back yoke 22, and an armature winding 23. A plurality of teeth 21 are provided in a ring shape. An armature winding 23 is wound around the tooth 21. The back yoke 22 magnetically shorts the teeth 21 on the side opposite to the field element 3. The back yoke 22 has a hole 20 at a position facing the inner ring 34 on the rotation axis P. A rotating shaft (not shown) is rotatably inserted in the hole 20. An alternating current flows through the armature winding 23 to supply a rotating magnetic field to the field element 3.

  In the present embodiment, a case where 24 teeth are both provided is illustrated.

  The armature 1 further includes a short-circuiting ring 14 on its outer edge, and the armature 2 further includes a short-circuiting ring 24 on its outer edge. The short-circuiting ring 36 faces the field element 3 via a gap in the radial direction. In other words, the short-circuiting ring 36 is arranged on the outer peripheral side of the field element 3. Although the short-circuiting rings 14, 24, and 36 are shown separated along the rotation axis P in FIG. 1, they are brought into contact with each other and short-circuited in an actual axial gap type motor.

  However, each of the short-circuiting rings 14 and 24 is for magnetically short-circuiting the short-circuiting ring 36 and each of the back yokes 12 and 22. Therefore, the contact between each of the short-circuiting rings 14 and 24 and the short-circuiting ring 36 is not necessarily assumed.

  The radially inner end face of the short-circuiting ring 36 is closer to the rotation axis P than the radially inner end face of each of the short-circuiting rings 14, 24. In other words, the short-circuiting ring 36 can be understood as a projecting portion that projects to the field element 3 more than the short-circuiting rings 14 and 24.

  A plurality of protrusions 361 are formed on the radially inner end face of the short-circuiting ring 36 so as to protrude inward. The plurality of protrusions 361 are formed side by side along the axial direction. The short-circuiting ring 36 faces the main outer ring 333 via a gap in the radial direction. The pitch between the protrusions 334 of the main outer ring 333 and the pitch between the protrusions 361 of the short-circuiting ring 36 are approximately the same. In the illustrations of FIGS. 2 to 4, three protrusions 361 are provided in the same manner as the protrusions 334. 2 to 4, each of the protrusions 334 faces each of the protrusions 361, and the widths of the protrusions 334 and 336 facing each other in the axial direction are substantially the same.

  Further, when the case of the axial gap type motor holds the back yokes 12 and 22 from the outside in the radial direction, each of the back yokes 12 and 22 and the short-circuiting ring 36 may be magnetically short-circuited by the case. . In this case, the short-circuiting rings 14 and 24 can be omitted. Further, the short-circuiting ring 36 may be configured as a part of the case.

  In the present embodiment, the field winding 41 is arranged around the rotation axis P between the back yoke 12 and the field element 3. More specifically, it is provided on the outer side in the radial direction than the group of armature windings 13 arranged in the circumferential direction, and is arranged closer to the rotation axis P than the short-circuiting ring 14. The field winding 42 is disposed around the rotation axis P between the back yoke 22 and the field element 3. More specifically, it is provided radially outside the group of armature windings 23 arranged in the circumferential direction, and is arranged closer to the rotation axis P than the short-circuiting ring 24. In other words, the short-circuiting rings 14 and 24 are located outside the field windings 41 and 42 in the radial direction.

  A current flows through the field windings 41 and 42 to generate a magnetic field along the rotation axis P. Since the subfield magnetic flux is obtained by the magnetic field, the expression that the subfield magnetic flux is generated by the field windings 41 and 42 is simply adopted below.

  However, the subfield magnetic fluxes generated by the field windings 41 and 42 are opposite to each other in the direction along the rotation axis P.

  In addition, the armature windings 13 and 23 and the field windings 41 and 42 do not indicate each one of the conductive wires constituting the armature windings 13 and 23 but indicate an aspect in which the conductive wires are wound together. The same applies to the drawings. In addition, the drawing lines at the start and end of winding and their connection are also omitted in the drawings.

  FIG. 5 is a developed view of the circumferential cross section of the field element 3 at the radial position where the partition wall 35 exists, and the armature windings 13 and 23 are omitted.

  4 and 5 schematically show the flow of the main field magnetic flux φm and the flow of the subfield magnetic flux φa.

  Part of the main field magnetic flux φm flows between the magnet magnetic pole portion 31 and the soft magnetic body 32 via the teeth 11 and 21 and the back yokes 12 and 22. As a result, the soft magnetic body 32 is magnetized by the main field magnetic flux φm.

  On the other hand, most of the subfield magnetic flux φa flows through the soft magnetic body 32 via the teeth 11 and 21, the back yokes 12 and 22, and the short-circuiting rings 14, 24 and 36. As a result, the soft magnetic body 32 is also magnetized by most of the subfield magnetic flux φa.

  That is, the soft magnetic body 32 is magnetized by a part of the main field magnetic flux φm and most of the subfield magnetic flux φa, and functions as an induced magnetic pole (hereinafter referred to as “soft magnetic pole”). Therefore, the strength of the soft magnetic pole increases or decreases by changing the magnitude and direction of the subfield magnetic flux φa. Since the sub-field magnetic flux φa is controlled by the current flowing through the field windings 41 and 42, the field element 3 can be weakened or strengthened by the current.

  In the embodiment shown in FIG. 5, the direction of the main field magnetic flux φm flowing through the teeth 11 and the soft magnetic body 32 is opposite to the direction of the subfield magnetic flux φa flowing through the teeth 11 and the soft magnetic body 32. The direction of the main field magnetic flux φm flowing through the teeth 21 and the soft magnetic body 32 is opposite to the direction of the sub-field magnetic flux φa flowing through the teeth 21 and the soft magnetic body 32. Therefore, the subfield magnetic flux φa in FIG. 5 corresponds to the case where the field weakening is applied.

  As described above, the subfield magnetic flux φa flows between the field element 3 and the short-circuiting ring 36. Further, a part of the main field magnetic flux φm flows through the above-described path, but the other part flows through the same path as the sub-field magnetic flux φa. Therefore, both the main field magnetic flux φm and the subfield magnetic flux φa flow between the field element 3 and the short-circuiting ring 36.

  FIGS. 6 and 7 are cross-sectional views along the radial direction, and both figures show a short circuit with the field element 3 in a state where the axial positional relationship between the field element 3 and the short-circuiting ring 36 is different. A working ring 36 is shown. Further, the flow of magnetic flux is schematically shown by a broken line. Hereinafter, the three protrusions 334 are referred to as protrusions 334A to 334C from one of the axial directions, and the three protrusions 361 are referred to as protrusions 361A to 361C from one of the axial directions. Here, as shown in FIG. 6, it is assumed that a state in which the protrusions 334A to 334C are positioned at the same height as the protrusions 361A to 361C in the axial direction is a reference state.

  In the reference state, the magnetic flux flows along the substantially radial direction between the protrusions 334A and 361A, between the protrusions 334B and 361B, and between the protrusions 334B and 361B.

  In the illustration of FIG. 7, the field element 3 is located on one side in the axial direction (upper side in the drawing) than the short-circuiting ring 36. That is, the protrusions 334A to 334C are located on one side in the axial direction from the protrusions 361A to 361C, respectively. However, the protrusion 334B is closer to the protrusion 361B than the protrusion 361A, and the protrusion 334C is closer to the protrusion 361C than the protrusion 361B.

  Also in this case, the magnetic flux flows between the protrusions 334A and 361A, between the protrusions 334B and 361B, and between the protrusions 334B and 361B. However, magnetic flux flows diagonally between these.

  In general, a force acts on two magnetic bodies through which a magnetic flux flows so as to minimize the path of the magnetic flux, that is, approach each other. Therefore, also in the case of FIG. 7, the force acts so that the field element 3 approaches the short-circuiting ring 36. Therefore, a force to return to the reference state, that is, a force (hereinafter referred to as a restraining force) acts on the other side in the axial direction on the field element 3 (see a block arrow in FIG. 7). Thereby, the movement (or vibration, the same applies hereinafter) of the field element 3 in the axial direction can be suppressed.

  Also in the illustration of FIG. 8, the field element 3 is located on one side in the axial direction from the short-circuiting ring 36. However, the protrusion 334B is closer to the protrusion 361A than the protrusion 361B, and the protrusion 334C is closer to the protrusion 361B than the protrusion 361C. Since the magnetic flux flows through the shortest distance, unlike FIG. 7, the magnetic flux flows between the protrusions 334B and 361A and between the protrusions 334C and 361B. Therefore, in this case, due to the magnetic flux, a force directed to one side in the axial direction acts on the field element 3 (see the block arrow in FIG. 8). This is not preferable because the field element 3 is a force that moves away from the reference state.

  Therefore, the maximum distance that the field element 3 can move in the axial direction from the reference state needs to be less than half of the pitch of the protrusions 334 and 361. In other words, the pitch of the protrusions 334 and 361 is set to exceed twice the maximum distance. This maximum distance is determined by the specifications of the axial gap type motor, and can be obtained in advance by simulation or experiment. Or you may think that the said maximum distance is prescribed | regulated by the bearing which supports a shaft. For example, the half value of the movable distance in the axial direction of the inner ring relative to the outer ring of the bearing may be grasped as the maximum distance.

  Thus, the state shown in FIG. 8 can be avoided, and a force for the field element 3 to return to the reference state acts as shown in FIG.

  9 to 12 are conceptual views of the field element 3 and the short-circuiting ring 36 for a motor having 3 to 5 protrusions 334 and 361 and a motor having no protrusions 334 and 361, respectively. FIG.

  FIG. 13 shows the restraining force acting on the field element 3 of FIGS. 9 to 12. In FIG. 13, motors not provided with the protrusions 334 and 361 are distinguished from motors provided with 3 to 5 protrusions 334 and 361 by reference numerals A to D, respectively. A indicates a motor without the protrusions 334 and 361, and B to D indicate motors with 3 to 5 protrusions 334 and 361, respectively. The axial width of the field elements 3 and the short-circuiting ring 36 of the motors A to D is 14.5 mm, and the axial widths of the protrusions 334 and 361 of the motors A to C are 2.0 mm and 1. 5 mm and 1.2 mm. In FIG. 13, the positive and negative polarities of the force generated in the field element 3 are defined as follows. That is, the force in the same direction as the moving direction in the axial direction of the field element 3 is defined as positive.

  As can be understood from FIG. 13, by providing the protrusions 334 and 336, the suppression force can be increased significantly (about 5 times).

  In the present embodiment, even when no current flows through the field windings 41 and 42, that is, when the subfield magnetic flux φa does not flow between the field element 3 and the short-circuiting ring 36. However, the main field magnetic flux φm flows between the field element 3 and the short-circuiting ring 36. Therefore, the axial movement of the field element 3 can be suppressed by the main field magnetic flux φm. Therefore, even when no field weakening or strong fielding is performed (that is, even when no current is passed through the field windings 41 and 42), the movement of the field element 3 in the axial direction is suppressed. Is done.

  The radial distance between the protrusions 334 and 361 is preferably shorter than the axial distance between the field element 3 and the armatures 1 and 2 (so-called air gap). Thereby, the magnetic resistance between the field element 3 and the short-circuiting ring 36 can be reduced, and the movement of the field element 3 in the axial direction can be effectively suppressed.

  In the above-described example, a nonmagnetic resin that fills the space between the plurality of protrusions 334 may be provided. Such a resin is provided by, for example, molding. More specifically, the field element 3 is housed in a mold that creates a gap between the plurality of protrusions 361, and a resin is poured into the gap to be cured. Thus, if resin is provided, the intensity | strength of the field element 3 can be improved. Resin may be provided between the plurality of protrusions 361, and in this case, the strength of the short-circuiting ring 36 can be improved.

Second embodiment.
The axial gap type motor according to the second embodiment is different from the first embodiment in the configuration of the field element 3.

  FIG. 14 is a perspective view showing an example of a part of the configuration of the field element 3 according to the second embodiment. Here, in order to make the said structure easy to visually recognize, the part extended at 180 degrees in the circumferential direction was removed and shown. The field element 3 in FIG. 14 is different from the field element 3 in FIG.

  In the example of FIG. 14, the magnet magnetic pole portion 31 includes permanent magnets 314 to 316 and a soft magnetic body 317. The soft magnetic body 317 is located between the permanent magnets 314 and 315 in the circumferential direction. In other words, the permanent magnet 314 is adjacent from one side of the soft magnetic body 317 in the circumferential direction, and the permanent magnet 315 is adjacent from the other side of the soft magnetic body 317 in the circumferential direction. For example, the area of the soft magnetic body 317 viewed from the axial direction is smaller than the area of the soft magnetic body 32 viewed from the axial direction.

  The permanent magnets 314 and 315 have a flat plate shape, for example, and extend in the radial direction. The permanent magnet 316 is disposed on the outer peripheral side with respect to the soft magnetic body 317. The permanent magnet 316 has a flat plate shape, for example, and extends in the circumferential direction.

  The permanent magnets 314 and 315 are all arranged with the same first magnetic pole face (for example, N pole) facing the soft magnetic body 317. For example, the permanent magnets 314 and 315 are all magnetized in the circumferential direction to realize such an arrangement. The permanent magnet 316 is disposed with the first magnetic pole face facing the soft magnetic body 317. For example, the permanent magnet 316 is magnetized in the radial direction to realize such an arrangement. As a result, the soft magnetic body 317 exhibits the same first magnetic pole face on both sides in the axial direction.

  The partition wall 35 of the holding body 30 is provided between the permanent magnets 314 to 316 and the soft magnetic bodies 32 and 317, and holds these in cooperation with the outer ring 33 and the inner ring 34.

  A protrusion 334 is provided on the outer peripheral surface of the outer ring 33 as in FIG.

  FIG. 15 is a cross-sectional view illustrating the configuration of the axial gap motor. The cross section includes the rotation axis P, is a plane parallel to the rotation axis P, and is in a position where the soft magnetic body 317 appears. FIG. 16 is a developed view of the circumferential cross section of the field element 3 at the radial position where the soft magnetic body 317 is present, and the armature windings 13 and 23 are omitted.

  15 and 16 schematically show the flow of the main field magnetic flux φm and the flow of the subfield magnetic flux φa. Part of the main field magnetic flux φm flows between the magnet magnetic pole portion 31 and the soft magnetic body 32 via the teeth 11 and 21 and the back yokes 12 and 22. This main field magnetic flux φm is mainly generated by the permanent magnets 314 and 315. Therefore, the permanent magnets 314 and 315 contribute to the magnetization of the soft magnetic body 32. Another part of the main field magnetic flux φm flows between the field element 3 and the short-circuiting ring 36 via the teeth 11 and 21, the back yokes 12 and 22, and the short-circuiting rings 14 and 24. A part of the main field magnetic flux φm is mainly generated by the permanent magnet 316.

  The sub-field magnetic flux φa flows between the field element 3 and the short-circuit ring 36 via the teeth 11 and 21, the back yokes 12 and 22, and the short-circuit rings 14 and 24.

  As described above, since the magnetic flux flows between the field element 3 and the short-circuiting ring 36, when the field element 3 moves to one side in the axial direction with respect to the short-circuiting ring 36, the other of the axial direction A sideward force acts on the field element 3. Thereby, it is possible to suppress the axial movement of the field element 3 in the same manner as in FIG.

  Further, as shown in FIGS. 15 and 16, the permanent magnet 316 that is magnetized in the radial direction is provided on the outer peripheral side of the soft magnetic body 317, so that the gap between the field element 3 and the short-circuit ring 36 is The main field magnetic flux φm flowing through can be increased. As a result, the force generated in the field element 3 due to the magnetic flux flowing through the field element 3 and the short-circuiting ring 36 increases. Therefore, the movement of the field element 3 in the axial direction can be further suppressed as compared with the field element 3 of FIG.

Third embodiment.
The axial gap type motor according to the third embodiment is different from the first embodiment in the configuration of the field element 3.

  In the second embodiment, as illustrated in FIG. 17, a nonmagnetic portion 335 is provided on the outer ring 33 of the holding body 30. In the illustration of FIG. 17, the nonmagnetic portion 335 is formed by a recess formed on the outer peripheral side surface of the outer ring 33. However, the nonmagnetic portion 335 is not limited to this, and may be a resin or the like. The nonmagnetic portion 335 is provided at a position corresponding to (boundary) between the magnet magnetic pole portion 31 and the soft magnetic body 32 in the circumferential direction, and extends from the end of the outer ring 33 in the axial direction, for example.

  The main field magnetic flux φm flowing in the vicinity of the outer ring 33 can flow through the following two paths. The first path is a path that flows along the circumferential direction between the magnetic pole portion 31 and the soft magnetic body 32 in the outer ring 33. The second path is a path (a path through which the subfield magnetic flux φa flows) that flows along the radial direction in the outer ring 33 and flows to the short-circuiting ring 36 through the air gap.

  In the second embodiment, the non-magnetic portion 335 is provided in the outer ring 33 between the magnetic pole portion 31 and the soft magnetic body 32 (boundary). The field magnetic flux φm tends to pass through the second path. Therefore, the magnetic flux flowing between the field element 3 and the short-circuiting ring 36 can be increased. As a result, the force acting on the field element 3 can be increased, and the movement of the field element 3 in the axial direction can be further suppressed.

  In any of the above embodiments, as the short-circuiting rings 14 and 24, an iron core in which an electromagnetic steel sheet is wound around the rotation axis P can be employed. Since the iron core has a small magnetic resistance in the axial direction, it is suitable for magnetic short-circuiting between the back yokes 12 and 22 and the short-circuiting ring 36.

  In the above example, both the main outer ring 333 and the short-circuit ring 36 are provided over the entire circumference, but only one of them may be formed separately in the circumferential direction. For example, the main outer ring 333 may be provided over the entire circumference, and the short-circuiting ring 36 may be separated in the circumferential direction. In this case, it is desirable that the short-circuiting rings 36 be separated from each other at equal intervals in the circumferential direction. This is because force can be applied to the field element 3 in rotational symmetry.

  Similarly, the short-circuiting ring 36 may be provided over the entire circumference, and the main outer ring 333 may be separated in the circumferential direction. Also in this case, it is desirable that the main outer ring 333 be separated from each other at equal intervals in the circumferential direction. This is because force can be applied to the field element 3 in rotational symmetry.

  In addition, if both the main outer ring 333 and the short-circuiting ring 36 are provided over the entire circumference, a restraining force acts on the field element 3 over the entire circumference. Therefore, the movement of the field element 3 in the axial direction can be suppressed in a balanced manner.

  The various embodiments described above can be appropriately combined as long as the functions of each other are not impaired.

Apply.
The above-described embodiments and modifications are configured in an axial gap type motor. Therefore, these can be applied to motors for automobiles such as in-wheel motors.

DESCRIPTION OF SYMBOLS 1, 2 Armature 11, 21 Teeth 12, 22 Back yoke 13, 23 Armature winding 14, 24, 36 Short circuit ring 3 Field element 30 Holding body 31 Magnet magnetic pole part 32 Soft magnetic body 33 Outer ring 311, 312 , 314 to 316 Permanent magnet 313, 317 Soft magnetic material 41, 42 Field winding

Claims (10)

A magnet magnetic pole part (31) that rotates around a predetermined rotation axis (P) and includes a permanent magnet, a soft magnetic body (32), and a soft magnetic body provided on the outer peripheral side of the magnet magnetic pole part and the soft magnetic body A magnetic outer member (33), wherein the magnet magnetic pole portions and the soft magnetic bodies are alternately arranged in a circumferential direction with respect to the rotating shaft, and all of the magnet magnetic pole portions (31) are arranged on the rotating shaft. The same polarity surface of the first polarity on both sides presents a magnetic pole surface of a second polarity different from the first polarity toward the outside in the radial direction with respect to the rotating shaft, and the outer peripheral surface of the outer member has A rotor (3) provided side by side along the axial direction along the rotation axis and formed with a plurality of first protrusions (334) protruding outward in the radial direction;
A first armature winding (13), a plurality of first teeth (11) around which the first armature winding is wound, facing the rotor from one side of the rotating shaft, and the rotor A first stator (1) having a first back yoke (12) for magnetically short-circuiting the plurality of first teeth on the opposite side,
A second armature winding (23), a plurality of second teeth (21) around which the second armature winding is wound, facing the rotor from the other side of the rotating shaft, and the rotor A second stator (2) having a second back yoke (22) for magnetically short-circuiting the plurality of second teeth on the opposite side,
A first field winding (41) disposed around the rotation axis between the first back yoke and the rotor and generating a magnetic field in a first direction along the rotation axis;
A second field winding (42) disposed around the rotation axis between the second back yoke and the rotor and generating a magnetic field in a direction opposite to the first direction;
Each of the first back yoke and the second back yoke is magnetically short-circuited on the outer edge side of the first back yoke and the second back yoke, and protrudes inward in the radial direction to face the outer member via a gap. An axial gap type motor provided with a short-circuiting ring (36) provided with protrusions (361) arranged along the axial direction at a pitch substantially equal to the plurality of first protrusions.   2. The axial gap motor according to claim 1, wherein at least one of the outer member (33) and the short-circuiting ring (36) is formed by electromagnetic steel plates laminated in the axial direction.   Of the first protrusion (334) and the second protrusion (361), a protrusion belonging to at least one of the outer member (33) and the short-circuiting ring (36) in the axial direction. The axial gap motor according to claim 2, wherein the thickness is an integral multiple of the thickness of the electromagnetic steel sheet.   The nonmagnetic material (335) is formed in a portion corresponding to the portion between the magnet magnetic pole portion (31) and the soft magnetic material (32) in the outer member (33). An axial gap motor according to any one of the above. The first stator (1) further includes a first ring (14) for magnetically short-circuiting the short-circuiting ring (36) and the first back yoke (12),
The second stator (2) further includes a second ring (24) for magnetically short-circuiting the short-circuiting ring (36) and the second back yoke (22),
5. The axial gap motor according to claim 1, wherein the first ring or the second ring is an iron core in which an electromagnetic steel plate is wound around the rotation axis. Each of the magnet magnetic pole portions (32)
A second soft magnetic material (317);
The axial gap type motor according to any one of claims 1 to 5, further comprising a first permanent magnet (316) that is positioned on an outer peripheral side of the second soft magnetic body and is magnetized in the radial direction. . Each of the magnetic pole portions (31) has a second permanent magnet (314) adjacent to the second soft magnetic body (317) from one side in the circumferential direction, and the second soft magnetic body. And a third permanent magnet (314) adjacent from the other side in the circumferential direction.
The second and third permanent magnets are arranged such that a magnetic pole surface having the same polarity as a magnetic pole surface toward which the first permanent magnet faces the second soft magnetic body is directed toward the second soft magnetic body. 6. An axial gap motor according to 6. Each of the magnet magnetic pole portions is
A second soft magnetic body (313);
A first permanent magnet (311) positioned closer to the first stator (1) than the second soft magnetic body;
A second permanent magnet (312) positioned closer to the second stator (2) than the second soft magnetic body,
6. The second permanent magnet according to claim 1, wherein the second permanent magnet is disposed with a magnetic pole face having the same polarity as the magnetic pole face directed to the second soft magnetic body toward the second soft magnetic body. The axial gap type motor according to any one of the above.   The axial according to any one of claims 1 to 8, wherein a resin is provided between at least one of the first protrusions (334) and between the second protrusions (361). Gap type motor.   The radial distance between the outer member (33) and the short-circuiting ring (36) is such that the rotor (3) and the first stator (1) or the second stator (2). The axial gap type motor according to claim 1, which is smaller than an air gap between the two.

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