JP2010017011A - Axial gap motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial gap motor which suppresses a rim of a rotor frame from being widened radially outward during high speed rotation and applies uniform pre-load to the rotor frame on both sides in the shaft direction. <P>SOLUTION: The axial gap motor 10 includes a rotor 11 rotatable around a rotary shaft and a stator 12 arranged opposite to the rotor from at least one side in the rotary shaft direction. The rotor 11 includes a plurality of radial ribs 35 circumferentially arranged at predetermined intervals and radially extending, a rotor frame 33 with a rim 37 and shafts 36 each provided on inner and outer diameter sides of the plurality of radial ribs 35, and a first and second outer circumferential rings 25A, 25B press-fitted to an outer periphery of the rim 37. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an axial gap type motor.

  2. Description of the Related Art Conventionally, for example, a rotor that can rotate around a rotation axis and a stator that is disposed to face the rotor from at least one side in the direction of the rotation axis are provided. An axial gap type motor that forms a magnetic flux loop is known (see, for example, Patent Document 1).

  As shown in FIG. 8, the axial gap motor 100 described in Patent Document 1 includes a rotor 101 that can rotate around a rotation axis and a pair of stators 102 that are opposed to each other so as to be sandwiched from both sides in the rotation axis direction. The rotor 101 is configured such that magnetic circuit elements such as a main magnet piece 103, a sub magnet piece 104, and a magnetic member 105 are accommodated in a rotor frame 106 made of a nonmagnetic material. The rotor frame 106 includes a plurality of ribs 107 that are arranged in the circumferential direction at predetermined intervals and extend in the radial direction, and a shaft portion 108 and a rim portion 109 that are connected by the plurality of ribs 107.

JP 2008-104278 A

  In this axial gap type motor 100, both axial ends of the rim portion 109 may spread outward in the radial direction due to centrifugal force during high-speed rotation, as indicated by the dotted lines in FIG. In order to deal with this, it is conceivable to press-fit the outer ring 110 from one side as shown in FIG. 10 and suppress the spread of the rotor frame 106 by preloading by press-fitting to compensate for the rotational strength of the rotor frame 106. When the outer peripheral ring 110 is press-fitted from one direction, the preload is not evenly applied to both sides in the axial direction, and there is a problem that a relatively large preload difference is generated on both sides in the axial direction.

  That is, as shown in FIG. 11A, the preload is small on the front end side (left side in the figure) in the press-fitting direction, and the preload is large on the opposite side (right side in the figure). As shown in FIG. 1, there is a problem that the preload is not evenly applied at both ends in the axial direction, and a displacement difference due to centrifugal force occurs at high speed rotation at both ends in the axial direction.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to suppress the spread of the rim portion of the rotor frame to the radially outer side during high-speed rotation and to reduce the preload acting on the rotor frame on both axial sides. It is to provide an axial gap type motor that can be made uniform.

In order to achieve the above object, the invention described in claim 1
A rotor (rotor 11 in an embodiment described later) rotatable around a rotation axis;
An axial gap type motor (axial gap type motor 10 in an embodiment to be described later) comprising a stator (stator 12 in an embodiment to be described later) opposed to the rotor from at least one side in the rotation axis direction,
The rotor is
A plurality of ribs (radial ribs 35 in the embodiment described later) arranged at predetermined intervals in the circumferential direction and extending in the radial direction, and shaft portions (described later) provided on the inner diameter side and the outer diameter side of the plurality of ribs, respectively. A rotor frame (rotor frame 33 in an embodiment described later) having a shaft portion 36 in the embodiment) and a rim portion (rim portion 37 in an embodiment described later);
A main magnet piece (a main permanent magnet piece 41 in an embodiment described later) magnetized in the rotation axis direction and disposed between the ribs adjacent in the circumferential direction;
A plurality of sub-magnet pieces (sub-permanent magnet pieces 43 in the embodiments described later) magnetized in a direction perpendicular to the rotation axis direction and the radial direction and disposed on at least one side of the rib in the rotation axis direction;
A magnetic member (a magnetic member 42 in an embodiment described later) disposed between the adjacent sub-magnet pieces;
First and second outer peripheral rings (outer peripheral rings 25A and 25B in embodiments described later) respectively press-fitted into the outer peripheral part of the rim part;
It is characterized by providing.

In order to achieve the above object, the invention described in claim 2
A rotor (rotor 11 in an embodiment described later) rotatable around a rotation axis;
An axial gap type motor (axial gap type motor 10 in an embodiment to be described later) comprising a stator (stator 12 in an embodiment to be described later) opposed to the rotor from at least one side in the rotation axis direction,
The rotor is
A plurality of ribs (radial ribs 35 in the embodiment described later) arranged at predetermined intervals in the circumferential direction and extending in the radial direction, and shaft portions (described later) provided on the inner diameter side and the outer diameter side of the plurality of ribs, respectively. A rotor frame (rotor frame 33 in an embodiment described later) having a shaft portion 36 in the embodiment) and a rim portion (rim portion 37 in an embodiment described later);
Magnet pieces (main permanent magnet pieces 41 in the embodiments described later) respectively disposed between the ribs adjacent in the circumferential direction;
A plurality of non-magnetic members (non-magnetic members 63 in the embodiments described later) disposed on at least one side of the rib in the rotation axis direction;
Magnetic members disposed between adjacent non-magnetic members, magnetic members 42) in embodiments described later,
First and second outer peripheral rings (outer peripheral rings 25A and 25B in embodiments described later) press-fitted into the outer peripheral portion of the rim portion;
It is characterized by providing.

In addition to the configuration of the invention described in claim 1 or 2, the invention described in claim 3
A gap (described later) between the outer peripheral portion of the rim portion, which is a projection of the connecting portion between the plurality of ribs and the inner peripheral surface of the rim portion, in the radial direction and the inner peripheral surfaces of the first and second outer peripheral rings. It is characterized by having a relief groove 26) in the embodiment.

In addition to the configuration of the invention described in claim 3, the invention described in claim 4
The gap is formed by notches (notches 26A and 26B in the embodiments described later) provided at end portions of the first and second outer peripheral rings.

In addition to the structure of the invention in any one of Claims 1-4, the invention of Claim 5 is
The first and second outer peripheral rings are press-fitted into the outer peripheral portion of the rim portion from opposite sides in the rotation axis direction.

In addition to the structure of the invention in any one of Claims 1-5, the invention of Claim 6 is
The first and second outer peripheral rings are made of a nonmagnetic member.

  According to the first and second aspects of the invention, the first and second outer peripheral rings can suppress the rim portion of the rotor frame from spreading radially outward during high-speed rotation. By dividing into two rings, the preload acting on the rotor frame can be made uniform on both sides in the axial direction.

  According to invention of Claim 3, the outer peripheral part of the rim | limb part which projected the connection part of the some rib and the inner peripheral surface of a rim | limb part to radial direction, and the inner peripheral surface of a 1st and 2nd outer peripheral ring By forming a gap therebetween, the stress due to the first and second outer peripheral rings can be relieved at the connecting portion between the highly rigid rib and the rim portion. Moreover, the relaxation of the stress of the connection part of a rib and a rim | limb part can reduce the displacement difference of a connection part and an axial direction both ends.

  According to invention of Claim 4, a notch can be utilized as a guide at the time of press fit by forming a clearance gap by the notch provided in the edge part of the 1st and 2nd outer periphery ring.

  According to the invention of claim 5, the first and second outer peripheral rings are press-fitted into the outer peripheral portion of the rim portion from the opposite side in the rotational axis direction, so that the preload acting on the rotor frame is more even on both axial sides. can do.

  According to the invention of claim 6, since the first and second outer peripheral rings are made of a non-magnetic member, it is possible to prevent the magnetic flux from being short-circuited through the first and second outer peripheral rings. . As a result, it is possible to prevent a reduction in motor generated torque and a reduction in efficiency.

  Hereinafter, an axial gap type motor according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

  An axial gap type motor 10 according to the present embodiment includes, for example, a substantially annular rotor 11 provided to be rotatable around a rotation axis O of the axial gap type motor 10, as shown in FIGS. A pair of stators 12 and 12 having a plurality of stator windings that are arranged opposite to each other so as to sandwich the rotor 11 from both sides in the direction of the axis O and generate a rotating magnetic field that rotates the rotor 11. Yes.

  The axial gap type motor 10 is mounted as a drive source in a vehicle such as a hybrid vehicle or an electric vehicle, for example, and an output shaft is connected to an input shaft of a transmission (not shown), whereby the driving force of the axial gap type motor 10 is obtained. Is transmitted to drive wheels (not shown) of the vehicle via a transmission.

  Further, when the driving force is transmitted from the driving wheel side to the axial gap type motor 10 during deceleration of the vehicle, the axial gap type motor 10 functions as a generator to generate a so-called regenerative braking force, and the kinetic energy of the vehicle body is electrically converted. Recover as energy (regenerative energy). Further, for example, in a hybrid vehicle, when the rotating shaft of the axial gap type motor 10 is connected to the crankshaft of an internal combustion engine (not shown), the axial gap motor 10 is also axially transmitted when the output of the internal combustion engine is transmitted to the axial gap type motor 10. The gap type motor 10 functions as a generator and generates power generation energy.

  Each stator 12 faces the rotor 11 along the direction of the rotation axis O from a substantially annular plate-shaped yoke portion 21 and a position at a predetermined interval in the circumferential direction on the facing surface of the yoke portion 21 facing the rotor 11. A plurality of teeth 22,..., 22 that protrude and extend in the radial direction, and stator windings (not shown) mounted between the appropriate teeth 22, 22 are configured.

  Each stator 12 is, for example, a 6N type having six main poles (for example, U +, V +, W +, U−, V−, W), and each stator 12 has U +, V +, W + poles. On the other hand, the U-, V-, and W-poles of the other stator 12 are set to face each other in the direction of the rotation axis O. For example, with respect to a pair of stators 12 and 12 opposed in the direction of the rotation axis O, three teeth 22 of one stator 12 corresponding to one of U +, V +, W + poles and one of U−, V−, W− poles, 22, 22 and the three teeth 22, 22, 22 of the other stator 12 corresponding to the other of the U +, V +, W + pole and the U−, V−, W− pole face each other in the direction of the rotation axis O. Thus, the energized state of the teeth 22 of one stator 12 and the teeth 22 of the other stator 12 facing each other in the direction of the rotation axis O is set so as to be reversed by an electrical angle.

  For example, as shown in FIG. 3, the rotor 11 includes a plurality of main magnet portions 31,..., A plurality of sub magnet portions 32,..., A rotor frame 33 made of a nonmagnetic material, an outer ring 25 </ b> A, 25B, and the main magnet portion 31 and the sub magnet portion 32 are accommodated in the rotor frame 33 in a state of being alternately arranged in the circumferential direction.

  The rotor frame 33 includes an inner annular ring shaft portion 36 and an outer circumferential annular ring rim portion 37 connected by a plurality of radial ribs 35,... 35 arranged at predetermined intervals in the circumferential direction. An output shaft connected to an external drive shaft (for example, an input shaft of a vehicle transmission) can be connected to the inner peripheral portion of the shaft portion 36.

  The main magnet portion 31 has a substantially sector plate-shaped main permanent magnet piece 41 magnetized in the thickness direction (that is, the rotation axis O direction), and a pair of sandwiching the main permanent magnet piece 41 from both sides in the thickness direction. The main permanent magnet pieces 41 and 41 of the main magnet portions 31 and 31 adjacent to each other in the circumferential direction are configured to have different magnetization directions as shown in FIG. The direction is set.

  The plurality of main magnet portions 31,..., 31 accommodated in the rotor frame 33 are sandwiched between the shaft portion 36 and the rim portion 37 from both sides in the radial direction, and in the circumferential direction via the radial ribs 35. They are arranged next to each other.

  In the rotor frame 33, the main permanent magnet piece 41 of each main magnet portion 31 is sandwiched by two radial ribs 35 from both sides in the circumferential direction, and the thickness of the main permanent magnet piece 41 in the direction of the rotation axis O is the diameter. The thickness of the direction rib 35 is equivalent to the thickness in the direction of the rotation axis O.

  The sub-magnet portion 32 includes a pair of sub-permanent magnet pieces 43 and 43 that sandwich the radial rib 35 from both sides in the direction of the rotation axis O in the rotor frame 33, and a pair of opposite faces in the direction of the rotation axis O. As shown in FIG. 4, the sub permanent magnet pieces 43 and 43 are magnetized in a direction (substantially circumferential direction) perpendicular to the rotation axis O direction and the radial direction, and the magnetization directions are different from each other.

  The thickness of the secondary permanent magnet piece 43 in the direction of the rotational axis O is equivalent to the thickness of the magnetic member 42 in the direction of the rotational axis O, and the circumferential width of the secondary permanent magnet piece 43 is the circumferential direction of the radial rib 35. It is equivalent to the width.

  In the rotor frame 33, the sub permanent magnet pieces 43, 43 of the sub magnet portions 32, 32 adjacent in the circumferential direction sandwich the magnetic member 42 of the main magnet portion 31 from both sides in the circumferential direction.

  In FIG. 3, in which the rotor frame 33 of the rotor 11 and the components other than the rotor frame 33 (that is, the main magnet portion 31 and the sub magnet portion 32) are shown separately, a pair facing each other in the direction of the rotation axis O. A space 43a in which the radial ribs 35 of the rotor frame 33 are disposed is formed between the sub permanent magnet pieces 43, 43 and between the main permanent magnet pieces 41, 41 adjacent in the circumferential direction.

  Further, the pair of sub permanent magnet pieces 43, 43 facing each other in the circumferential direction via the magnetic member 42 have different magnetization directions. The pair of sub permanent magnet pieces 43 and 43 arranged on one side in the direction of the rotation axis O have the same polarity as the magnetic pole on one side of the main permanent magnet piece 41 magnetized in the direction of the rotation axis O. A pair of sub-permanent magnet pieces 43, 43 that are opposed to each other and arranged on the other side in the direction of the rotation axis O are magnetic poles having the same polarity as the magnetic pole on the other side of the main permanent magnet piece 41 magnetized in the direction of the rotation axis O. Are arranged to face each other.

  That is, as shown in FIG. 4, for example, with respect to the main permanent magnet piece 41 in which one side in the rotation axis O direction is N-pole and the other side is S-pole, the magnetic member 42 is arranged in the circumferential direction on one side in the rotation axis O direction. The pair of sub permanent magnet pieces 43, 43 sandwiched from both sides of the magnet are arranged so that their N poles face each other in the circumferential direction, and the magnetic member 42 is sandwiched from both sides in the circumferential direction on the other side in the rotation axis O direction. The pair of sub permanent magnet pieces 43, 43 are arranged such that their S poles face each other in the circumferential direction. Accordingly, the magnetic fluxes of the main permanent magnet piece 41 and the sub permanent magnet pieces 43 and 43 are converged by the magnetic lens effect due to the so-called permanent magnet Halbach arrangement, and the effective magnetic flux linked to the stators 12 and 12 is relatively relative to each other. It is going to increase.

  The magnetic member 42 may be configured by laminating a plurality of electromagnetic steel plates, or may be manufactured by molding and sintering powder such as iron powder.

  In this embodiment, outer peripheral rings 25 </ b> A and 25 </ b> B made of a nonmagnetic material are fixed to the outer peripheral portion of the rim portion 37 of the rotor frame 33. The outer peripheral rings 25A and 25B each have a substantially half axial width of the rim portion 37, and are fixed by press-fitting from opposite sides in the axial direction.

  An area in which the radial ribs 35 are projected in the radial direction at the joint surface between the rim portion 37 and the outer peripheral rings 25A and 25B, that is, a concave relief groove (gap) 26 at the axial center of the inner peripheral surface of the outer peripheral rings 25A and 25B. Is formed over the entire circumference. The axial length of the escape groove 26 is formed to be the same as or slightly longer than the axial length of the radial rib 35. The escape grooves 26 are formed by inserting arc-shaped cutouts 26A and 26B formed at the axial ends of the inner peripheral surfaces of the outer peripheral rings 25A and 25B from the opposite sides in the axial direction. .

  The shapes of the cutouts 26A and 26B are not limited to this, and any shape can be adopted. Further, in the present embodiment, the escape groove 26 is formed on the inner peripheral surface of the outer peripheral rings 25A and 25B, but may be formed over the entire circumference in the axial center of the outer peripheral surface of the rim portion 37. .

  According to the axial gap type motor 10 configured as described above, the outer peripheral rings 25A and 25B are provided, thereby suppressing the rim portion 37 of the rotor frame 33 from spreading outward in the radial direction when the rotor 11 rotates at high speed. Can do. Further, by dividing the outer ring into two outer rings, the preload acting on the rotor frame 33 by the outer rings 25A and 25B can be made uniform in the axial direction, and further, these outer rings 25A and 25B can be made axial. Since the outer periphery of the rim portion 37 is press-fitted from the opposite side, the preload acting on the rotor frame 33 by the outer peripheral rings 25A and 25B can be made more uniform in the axial direction as shown by the arrows in FIG. A displacement difference at both axial ends of the rim portion 37 can be eliminated.

  Further, since the relief groove 26 is formed in a region in which the radial rib 35 is projected in the radial direction on the joint surface between the rim portion 37 and the outer peripheral rings 25A and 25B, the rigid radial rib 35 and the rim portion 37 have a high rigidity. The stress caused by the first outer ring and the second outer ring can be relieved at the connecting portion. By relieving the stress at the connecting portion between the radial rib 35 and the rim portion 37, the displacement difference between the connecting portion (center in the axial direction) and both axial ends can be reduced. In addition, since the stress generated in the rotor frame 33 is reduced, the press-fitting load of the outer peripheral rings 25A and 25B is also reduced. This eliminates the need for a large and expensive press-fitting device that can generate a high press-fitting load, thereby reducing the manufacturing cost of the motor 10. Furthermore, it is possible to prevent the occurrence of problems such as seizure during press fitting.

  Further, since the relief groove 26 is formed by notches 26A and 26B formed at the axial ends of the inner peripheral surfaces of the outer peripheral rings 25A and 25B, when the outer peripheral rings 25A and 25B are press-fitted into the rotor frame 33, It can be used as a guide.

  Moreover, according to the axial gap type motor 10 of this embodiment, since the outer ring 25A, 25B is made of a nonmagnetic material, it is possible to prevent the magnetic flux from being short-circuited through the outer ring 25A, 25B. As a result, it is possible to prevent the torque generated by the motor 10 from decreasing and the efficiency from decreasing.

  In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, in the above-described embodiment, the outer peripheral rings 25A and 25B are attached to the outer peripheral portion of the rim portion 37 of the rotor frame 33 by press-fitting, but may be attached so that compressive stress is generated in the rotor frame 33. Therefore, it may be attached by shrink fitting.

  Moreover, in the said embodiment, although the escape part 26 is formed over the perimeter of outer peripheral ring 25A, 25B as a concave escape groove, it is not limited to this, It is independent in the position corresponding to the radial direction rib 35. You may make it form. However, in this case, the independent relief portion 26 may be formed in the rim portion 37 in consideration of the phase alignment in the circumferential direction between the relief portion 26 and the radial rib 35.

  In the above embodiment, the stator 12 may be provided only on one side in the direction of the rotation axis O, and the sub-magnet portion 32 may be provided with the sub-permanent magnet piece 43 only on one side in the direction of the rotation axis O. You may prepare.

  Further, the axial gap type motor of the present invention is not limited to the Halbach type, and as a modified example, a nonmagnetic member 63 may be disposed in the submagnet portion 32 instead of the subpermanent magnet piece 43 as shown in FIG. .

1 is an overall perspective view of an embodiment of an axial gap motor according to the present invention. It is a disassembled perspective view of the axial gap type motor shown in FIG. It is a disassembled perspective view of the axial gap type motor shown in FIG. FIG. 2 is a partially exploded perspective view of a magnet piece and a magnetic member constituting a rotor of the axial gap type motor shown in FIG. 1. FIG. 2 is a partial perspective view of a rotor in which an outer peripheral ring is mounted on a rotor frame constituting the rotor of the axial gap type motor shown in FIG. 1. FIG. 3 is an axial sectional view for explaining preload by the outer peripheral ring of the rotor shown in FIG. 2. It is a disassembled perspective view of the modification of the axial gap type motor which concerns on this invention. 2 is an exploded perspective view of an axial gap type motor described in Patent Document 1. FIG. FIG. 9 is an axial sectional view for explaining displacement due to centrifugal force of the rotor shown in FIG. 8. FIG. 9 is a partial perspective view of a rotor in which an outer peripheral ring is mounted on the rotor frame shown in FIG. 8. FIG. 11 is an axial sectional view of the rotor of FIG. 10, (a) is a sectional view for explaining preload by the outer ring, and (b) is a sectional view for explaining displacement due to centrifugal force.

Explanation of symbols

10 Axial gap type motor 11 Rotor 12 Stator 25A, 25B Outer ring 26 Relief groove (gap)
26A, 26B Notch 31 Main magnet part 32 Sub magnet part 33 Rotor frame 35 Radial rib 36 Shaft part 37 Rim part 41 Main permanent magnet piece 42 Magnetic member 43 Secondary permanent magnet piece 63 Nonmagnetic member O Rotating shaft

Claims (6)

A rotor rotatable around a rotation axis;
An axial gap type motor comprising: a stator disposed opposite to the rotor from at least one side in a rotation axis direction;
The rotor is
A rotor frame having a plurality of ribs arranged in the circumferential direction at predetermined intervals and extending in the radial direction, and a shaft portion and a rim portion respectively provided on an inner diameter side and an outer diameter side of the plurality of ribs;
A main magnet piece magnetized in the direction of the rotation axis and disposed between the adjacent ribs in the circumferential direction;
A plurality of sub-magnet pieces magnetized in a direction orthogonal to the rotation axis direction and the radial direction and disposed on at least one side of the rib in the rotation axis direction;
Magnetic members respectively disposed between the adjacent sub magnet pieces;
First and second outer rings that are respectively press-fitted into the outer peripheral part of the rim part;
An axial gap type motor comprising: A rotor rotatable around a rotation axis;
An axial gap type motor comprising: a stator disposed opposite to the rotor from at least one side in a rotation axis direction;
The rotor is
A rotor frame having a plurality of ribs arranged in the circumferential direction at predetermined intervals and extending in the radial direction, and a shaft portion and a rim portion respectively provided on an inner diameter side and an outer diameter side of the plurality of ribs;
Magnet pieces respectively disposed between the ribs adjacent in the circumferential direction;
A plurality of non-magnetic members disposed on at least one side of the rib in the rotational axis direction;
Magnetic members respectively disposed between adjacent non-magnetic members;
First and second outer peripheral rings press-fitted into the outer peripheral part of the rim part,
An axial gap type motor comprising:   There is a gap between the outer peripheral portion of the rim portion projected in the radial direction from the connecting portion of the plurality of ribs and the inner peripheral surface of the rim portion, and the inner peripheral surfaces of the first and second outer peripheral rings. The axial gap type motor according to claim 1, wherein the axial gap type motor is provided.   4. The axial gap motor according to claim 3, wherein the gap is formed by a notch provided at an end portion of the first and second outer peripheral rings.   5. The axial gap type motor according to claim 1, wherein the first and second outer peripheral rings are press-fitted into the outer peripheral portion of the rim portion from opposite sides in the rotation axis direction.   6. The axial gap type motor according to claim 1, wherein the first and second outer peripheral rings are made of a nonmagnetic member.

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