JP2015154588A - Axial gap type motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial gap type motor capable of preventing a rotor from moving in an axial direction.SOLUTION: A short-circuiting ring is magnetically short-circuited with each of a back yoke 12 and a back yoke 22 at an outer edge side, opposes a magnetic field element 3 in a radial direction relative to a rotation axis P while interposing a cavity, and includes a protrusion 36 that protrudes to the magnetic field element 3 side.

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.

  The first aspect of the axial gap type motor according to the present invention is such that the magnet magnetic pole portion (31) including a permanent magnet and the soft magnetic body (32) rotate around a predetermined rotation axis (P) and rotate. The magnet magnetic pole portions (31) are alternately arranged in the circumferential direction with respect to the shaft, and all of the magnetic pole portions (31) have the same first polarity magnetic pole surface on both sides of the rotating shaft toward the radially outer side with respect to the rotating shaft. A rotor (3) presenting a magnetic pole surface of a second polarity different from one polarity, respectively, facing the rotor from one side of the rotating shaft, a first armature winding (13), and the first A plurality of first teeth (11) around which an armature winding is wound, and a first back yoke (12) for magnetically short-circuiting the plurality of first teeth on the side opposite to the rotor. , An alternating current flows through the first armature winding and the rotor A first stator (1) for supplying a first rotating magnetic field, a second armature winding (23), and a second armature winding that are opposed to the rotor from the other side of the rotating shaft. A plurality of second teeth (21) to be rotated, and a second back yoke (22) for magnetically short-circuiting the plurality of second teeth on the opposite side of the rotor, and the second armature A second stator (2) for supplying a second rotating magnetic field to the rotor by flowing the alternating current through a winding, and around the rotating shaft between the first back yoke and the rotor. A first field winding (41) for generating a magnetic field in a first direction along the rotation axis, and disposed around the rotation axis between the second back yoke and the rotor, A second field winding (42) for generating a magnetic field in a direction opposite to the first direction; And the second back yoke, which are magnetically short-circuited on the outer edge side thereof, are opposed to the rotor via a gap in the radial direction with respect to the rotating shaft, and protrude to the rotor side A short-circuiting ring (36).

  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 the rotor (2) includes the magnet magnetic pole part (31) and the soft magnetic body ( 32), and the holding body (30) has an outer ring (33) positioned on the outer peripheral side of the magnet magnetic pole part and the soft magnetic body, and the outer Of the ring, at least a portion facing the magnet magnetic pole portion is formed of a soft magnetic material.

  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 magnet magnetic pole part (31) and the soft magnetic body in the outer ring (33). A non-magnetic material is formed in a portion facing the portion between (32).

  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 first stator includes the short-circuit ring (36). And a first ring (14) that magnetically short-circuits the first back yoke (12), and the second stator includes the shorting ring (36) and the second back yoke (22). The first ring or the second ring is an iron core in which a magnetic steel sheet is wound around the rotation axis.

  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 each of the magnet magnetic pole portions includes a second soft 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 sixth aspect of the axial gap type motor according to the present invention is the axial gap type motor according to the fifth aspect, wherein each of the magnet magnetic pole portions (31) is formed on 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. .

  A seventh 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 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.

  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 seventh aspects, and is provided between the rotor (3) and the protrusion. The radial distance is smaller than the air gap between the rotor and the first stator or the second stator.

  According to the first aspect of the axial gap type motor of the present invention, the magnetic flux flows between the rotor and the protrusion of the short-circuiting ring. Therefore, when the rotor moves to one side in the axial direction with respect to the protrusion, a force directed to the other side in the axial direction acts on the rotor. Therefore, the movement of the rotor in the axial direction can be suppressed.

  According to the second 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 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 third aspect of the axial gap type motor of the present invention, the magnetic flux flowing from the magnet magnetic pole portion to the outer ring is more likely to flow to the protrusion (short-circuiting ring) than the soft magnetic material. Therefore, the magnetic flux between the rotor and the protrusion can be increased, and consequently the force 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 fourth 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 fifth 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 sixth 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 seventh aspect of the axial gap type motor of the present invention, the magnetic pole portion can be configured with a relatively simple configuration.

  According to the eighth 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 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 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 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 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 a perspective view which shows the structure of the field element of the axial gap type motor concerning 2nd Embodiment.

First embodiment.
FIG. 1 is a perspective view showing a configuration of an axial gap type motor according to a 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 has an outer ring 33, 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 the 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 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.

  A rotating shaft is inserted into the inner ring 34 and fixed. In FIGS. 1, 2, and 3, 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. The thickness of the short-circuiting ring 36 in the axial direction is, for example, approximately the same as the thickness of the field element 3 in the axial direction.

  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. 4 is a developed view of the circumferential cross section of the field element 3 at the radial position where the partition walls 35 exist, and the armature windings 13 and 23 are omitted.

  3 and 4 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. 4, 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. 4 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.

  FIG. 5 is a cross-sectional view along the radial direction, showing the field element 3 and the short-circuiting ring 36 in a state where the field element 3 is moved in the axial direction with respect to the short-circuiting ring 36. Further, the flow of magnetic flux is schematically shown by a broken line. In the illustration of FIG. 5, the field element 3 is positioned on one side (upper side in FIG. 5) in the axial direction with respect to the short-circuiting ring 36. More specifically, the surface 3a on one side of the field element 3 is positioned on one side in the axial direction from the surface 36a on one side of the short-circuiting ring 36, and the surface 3b on the other side of the field element 3 is for short-circuiting. It is located on one side in the axial direction from the surface 36 b on the other side of the ring 36. In this case, the magnetic flux flows obliquely between the field element 3 and the short-circuiting ring 36.

  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, in the case of FIG. 5, the force acts so that the field element 3 approaches the short-circuiting ring 36. Therefore, a force acts on the field element 3 on the other side in the axial direction (see a block arrow in FIG. 5). Thereby, the movement (or vibration, the same applies hereinafter) of the field element 3 in the axial direction can be suppressed.

  Even if the sub-field magnetic flux φa does not flow, the main field magnetic flux φm flows between the field element 3 and the short-circuiting ring 36. Therefore, the main field magnetic flux φm causes the field element 3 to move in the axial direction. Can be suppressed. Therefore, even when neither weak field nor strong field 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.

  Although the holding body 30 may be non-magnetic, when the outer ring 33 is located on the outer peripheral side of the magnet magnetic pole portion 31 and the soft magnetic body 32, at least the outer ring 33 is formed of a soft magnetic material. It is desirable. This is because the force that brings the field element 3 closer to the short-circuiting ring 36 increases as the magnetic resistance between them decreases.

  Moreover, only the part which opposes the magnet magnetic pole part 31 among the outer rings 33 may be formed with a soft magnetic material. Thereby, the main field magnetic flux φm between the magnet magnetic pole portion 31 and the short-circuiting ring 36 can be increased, and the force for bringing the field element 3 closer to the short-circuiting ring 36 can be increased.

  The main field magnetic flux φm flows through the partition wall 35 (FIG. 4). Therefore, it is desirable that the partition wall 35 (more specifically, the portion adjacent to the soft magnetic body 313 in the circumferential direction) is also formed of a soft magnetic material. Thereby, the main field magnetic flux φm can be increased as compared with the case where the partition wall 35 is nonmagnetic. Thereby, the torque of the motor can be increased.

  The holding body 30 may be a laminated steel plate laminated in the axial direction, for example. Thereby, the eddy current generated due to the main field magnetic flux φm and the subfield magnetic flux φa can be reduced. Only the outer ring 33 or only the partition walls 35 may be formed of laminated steel plates. In view of the fact that the main field magnetic flux φm flows through the soft magnetic body 313, only a portion of the partition wall 35 adjacent to the soft magnetic body 313 in the circumferential direction may be formed of a laminated steel plate.

  The distance in the radial direction between the field element 3 and the short-circuiting ring 36 is preferably shorter than the distance in the axial direction 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.

  FIG. 6 is a perspective view showing another example of a part of the 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. The field element 3 shown in FIG. 6 is different from the field element 3 shown in FIG.

  In the illustration of FIG. 6, 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. 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.

  FIG. 7 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. 8 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.

  7 and 8 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, the movement of the field element 3 in the axial direction can be suppressed.

  Further, as shown in FIG. 7, since the permanent magnet 316 magnetized in the radial direction is provided on the outer peripheral side of the soft magnetic body 317, the main current flowing between the field element 3 and the short-circuiting ring 36 is provided. The field magnetic flux φm 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.

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.

  In the second embodiment, as illustrated in FIG. 9, a nonmagnetic portion 331 is provided on the outer ring 33 of the holding body 30. In the illustration of FIG. 9, the nonmagnetic portion 331 is formed by a concave portion formed on the outer peripheral side surface of the outer ring 33. However, the nonmagnetic portion 331 is not limited to this, and may be a resin or the like. The nonmagnetic portion 331 is provided (boundary) between the magnet magnetic pole portion 31 and the soft magnetic body 32 in the circumferential direction, and extends, for example, from end to end of the outer ring 33 in the axial direction.

  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 between the magnet magnetic pole portion 31 and the soft magnetic body 32 along the circumferential direction in the outer ring 33. The second path is a path (a path through which the subfield magnetic flux φa flows) between the outer ring 33 and the short-circuiting ring 36 along the radial direction of the outer ring 33.

  In the second embodiment, the non-magnetic portion 331 is provided in the outer ring 33 between the magnet 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.

  Although the short-circuiting ring 36 (projection) is provided over the entire circumference, it may be formed by a plurality of projections that are separated from each other in the circumferential direction. In this case, it is desirable that the protrusions be provided at equal intervals in the circumferential direction. This is because force can be applied to the field element 3 in rotational symmetry.

  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 (8)

A magnet magnetic pole portion (31) that rotates around a predetermined rotation axis (P) and includes a permanent magnet, and a soft magnetic body (32) are alternately arranged in a circumferential direction with respect to the rotation axis, and the magnet magnetic pole portion ( 31) all present the same first polarity magnetic pole surface on both sides of the rotating shaft and the second polarity magnetic pole surface different from the first polarity toward the outside in the radial direction with respect to the rotating shaft. A rotor (3);
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 And a first back yoke (12) for magnetically short-circuiting the plurality of first teeth on the opposite side of the first armature winding, an alternating current flows through the first armature winding and A first stator (1) for supplying a rotating magnetic field;
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 And a second back yoke (22) for magnetically short-circuiting the plurality of second teeth on the opposite side, and the alternating current flows through the second armature winding, and the second arm is wound with respect to the rotor. A second stator (2) for supplying two rotating magnetic fields;
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 is opposed to the rotor via a gap in the radial direction with respect to the rotation shaft, An axial gap type motor comprising: a short-circuiting ring (36) having a projecting portion. The rotor (2) has a holding body (30) for holding the magnet magnetic pole part (31) and the soft magnetic body (32),
The holding body (30) has an outer ring (33) located on the outer peripheral side of the magnet magnetic pole part and the soft magnetic body,
2. The axial gap motor according to claim 1, wherein at least a portion of the outer ring facing the magnet magnetic pole portion is formed of a soft magnetic material.   The non-magnetic material is formed in a portion of the outer ring (33) facing a portion between the magnet magnetic pole portion (31) and the soft magnetic material (32). Axial gap type motor. The first stator further includes a first ring (14) for magnetically short-circuiting the short-circuiting ring (36) and the first back yoke (12);
The second stator further includes a second ring (24) for magnetically short-circuiting the short-circuiting ring (36) and the second back yoke (22),
The axial gap motor according to any one of claims 1 to 3, wherein the first ring or the second ring is an iron core in which an electromagnetic steel sheet is wound around the rotation axis. Each of the magnet magnetic pole portions is
A second soft magnetic material (317);
The axial gap type motor according to any one of claims 1 to 4, 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. 5. An axial gap motor according to 5. 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,
5. 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 radial distance between the rotor (3) and the protrusion is smaller than an air gap between the rotor and the first stator or the second stator. The axial gap type motor according to any one of 7 above.

Images