JP2009050045A - Axial gap motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial gap motor having a pair of rotors capable of independently rotating with a single stator. <P>SOLUTION: The axial gap motor has a structure in which a rotor and a stator are disposed oppositely in an axial direction of a rotary shaft. The motor is provided with a single stator, and a pair of rotors 210, 220 disposed on both the sides of the stator and each having an independent rotary shaft. Since the pair of rotors 210, 220 disposed on both the sides of the axial direction of the stator have the rotary shaft 213, 223, respectively, the rotors 210, 220 can be rotated with the single stator. Since the single stator is used, the number of parts does not increase. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an axial gap motor. In particular, the present invention relates to an axial gap motor including one stator core for a pair of rotors that rotate independently.

  An axial gap motor in which a rotor and a stator are arranged to face each other in the axial direction of a rotating shaft is known. For example, Patent Document 1 discloses a stator in which grooves are formed on both sides of a disk-shaped stator body made of a magnetic material, and an air-core coil is fitted in each of the grooves. And a motor is comprised by arrange | positioning a pair of rotor with a common rotating shaft on both sides of this stator.

JP 2005-237086

  However, in the motor described above, although a pair of rotors are arranged on both sides of the stator, both rotors are connected by a single rotating shaft, so there is no choice but to always rotate the pair of rotors synchronously. The rotor cannot be controlled independently.

  In addition, since the motor has a structure in which a groove is formed in the stator body and a coil is fitted into the groove, high accuracy is required for the machining of the groove and the coil, and the coil is previously wound around a tooth serving as a magnetic core. It cannot be rotated, and the assembly workability of the stator is inferior.

  Further, since the positions of the coils on both sides of the stator are the same, unevenness of torque generated in the rotor is increased by the magnetic field excited by each coil of the stator.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide an axial gap motor capable of independently rotating each of a pair of rotors with a single stator. .

  The axial gap motor of the present invention is an axial gap motor in which a rotor and a stator are arranged to face each other in the axial direction of a rotating shaft. The stator and the stator are arranged on both sides of the stator in the axial direction, and are independent of each other. And a pair of rotors having a rotation axis.

  According to the axial gap motor of the present invention, since the pair of rotors arranged on both sides in the axial direction of the stator have independent rotating shafts, each rotor can be rotated independently by one stator. Moreover, since only one stator is required, the number of parts does not increase.

  Hereinafter, the configuration of the present invention will be described in more detail.

<Stator core>
The stator includes a stator core and a coil. The stator core is made of a magnetic material such as a laminated steel plate or a soft magnetic powder compact. Among these, if it is a compacting body, even a complicated three-dimensional shape can be easily realized.

  The stator core includes a disk-shaped yoke and teeth on which the coil is sheathed. A rotation shaft of the motor is supported at the center of the yoke. In this example, a pair of rotors are arranged so as to sandwich the stator, and each rotor has an independent rotation shaft. Therefore, the rotation shaft of one rotor is pivotally supported on one surface side of the yoke, and the other surface is disposed on the other surface side of the yoke. The rotating shaft of the rotor is pivotally supported. Further, teeth are provided so as to protrude from each side surface of the yoke, and a coil is externally mounted on the teeth. The teeth are usually columnar, and the cross-sectional shape may be various shapes such as a circle and a quadrangle.

  Here, it is preferable that the teeth include a first tooth that protrudes toward one surface of the yoke and faces one rotor, and a second tooth that protrudes toward the other surface of the yoke and faces the other rotor.

  According to this configuration, one yoke is shared by the teeth facing one rotor and the teeth facing the other rotor. Therefore, it becomes possible to rotate a pair of rotors with a minimum number of parts of one stator core.

  In particular, the yoke of the stator core consists of a first yoke piece integral with the first tooth and a second yoke piece integral with the second tooth, and the first yoke piece and the second yoke piece are combined to form a disc shape. It is preferable to be made.

  According to this configuration, the first yoke piece and the second yoke piece can be combined to form a disk-shaped yoke, and at the same time as the disk-shaped yoke is formed, the first teeth and the second teeth are A stator core protruding from each side surface can be formed. A fan-shaped one can be suitably used for the first and second yoke pieces. Further, each tooth and each yoke piece may be configured to be separable. That is, a split stator core can be formed by joining columnar teeth to a yoke piece, and a stator core can be formed by collecting a plurality of the split stator cores. At that time, the stator may be assembled by winding the winding around the teeth and then joining the teeth to the yoke piece, or joining the teeth to the yoke piece and winding the winding around the teeth. Also good. In either case, the winding work is easy to perform. The number of teeth may be selected according to the number of motor poles.

  Furthermore, it is desirable that the first teeth and the second teeth are arranged at positions that are alternately shifted in the circumferential direction of the yoke.

  In the motor of the present invention, the rotational force acts on one rotor by the magnetic field of the coil sheathed on the first tooth, and the rotational force acts on the other rotor by the magnetic field of the coil sheathed on the second tooth. At that time, when the first teeth and the second teeth are alternately arranged in the circumferential direction of the yoke, when both rotors are rotated synchronously, the rotational force of one rotor is reduced. A rotational force is applied to the other rotor. On the other hand, when the first tooth and the second tooth are arranged at the same position in the yoke circumferential direction, when the rotational force is applied to one rotor, the rotational force is also applied to the other rotor. The For this reason, if the first teeth and the second teeth are alternately arranged in the circumferential direction of the yoke, the torque of the motor is more uneven than in the case where both teeth are arranged in the same position in the yoke circumferential direction. Can be greatly reduced.

  In addition, the teeth may include a flange portion that protrudes in a flange shape from an end portion on the opposite side to the side connected to the yoke. By this collar part, it can prevent that a coil slip | deviates from a tooth | gear, or falls.

<Rotor>
The rotor is a pair of members arranged so as to sandwich the stator. Each rotor has a rotation axis independent from each other, and is arranged coaxially with the stator. Further, a permanent magnet is usually disposed on the surface of the rotor that faces the stator. And attraction | suction and repulsion are repeated with respect to a permanent magnet with the magnetic field which generate | occur | produced by exciting the coil of a stator, and a rotor is rotated by it.

<Coil>
The coil is configured by winding a winding around the outside of the tooth. For the winding, a conductive wire having an outer periphery coated with an insulating coating is used. As the material for the wire, copper / copper alloy or the like can be suitably used, and for the insulation coating, enamel or the like can be used. When a three-phase alternating current is supplied using a plurality of such coils, the ends of the windings may be connected for each phase.

  The coil may be formed into an air-core coil in advance and fitted on the outside of the teeth. However, it is preferable to form the coil by winding the winding directly on the outside of the teeth. In the stator core constituting the motor of the present invention, since teeth protrude from both sides of the yoke, it is easy to wind a winding around the teeth.

  FIG. 1 shows a stator core used in a motor according to an embodiment of the present invention. In this example, the stator core 100 is configured by combining a total of 12 divided stator cores 10A and 10B.

  Each of the divided stator cores 10A and 10B is made of a compacted body of soft magnetic powder, and includes teeth 1A and 1B (first teeth 1A and second teeth 1B) and yoke pieces 2A and 2B (first yoke pieces 2A and second yoke). And 2B). Teeth 1A and 1B are columnar and the cross-sectional shape is substantially trapezoidal. On the other hand, the yoke pieces 2A and 2B are formed in a fan shape obtained by dividing a disk into 12 equal parts, and a notch 30 into which a bearing portion of a rotating shaft of a motor is fitted is formed at the center side. The notch 30 forms a circular hole 110 (see FIG. 1B) when the yoke pieces 2A and 2B are combined in a disk shape.

  Coils 40 (4A, 4B) are externally mounted on the teeth 1A (1B) of the divided stator core (see FIG. 2). Here, the coil 40 is formed by winding a winding having an enamel coating provided on the surface of a copper wire. Since the teeth 1A (1B) protrude from the yoke pieces 2A, 2B, the work of winding the winding around the teeth 1A (1B) can be easily performed.

  In order to more reliably insulate the divided stator cores 10A and 10B from the windings, contact portions with the windings in the divided stator cores 10A and 10B (the outer surfaces of the teeth 1A and 1B and the teeth protruding side surfaces of the yoke pieces 2A and 2B) May be provided with an insulator (not shown). The insulator is made of an insulating material such as a resin such as PPS (Poly Phenylene Sulfide) or LCP (Liquid Crystal Polymer). An inorganic filler such as glass (silicon dioxide), alumina (aluminum oxide), or titanium oxide may be added to the resin to improve the heat dissipation of the insulator. A specific configuration of the insulator includes a cylindrical section that includes a cylindrical portion that covers the outer periphery of the teeth 1A and 1B and a flange portion that protrudes from the peripheral edge of the cylindrical portion over the entire periphery. One flange portion is disposed so as to contact one surface of the yoke 20 (FIG. 1A). A space formed by the insulator having a cross-section is a storage portion (slot) for the coil 40 (FIG. 2). Such an insulator is easy to arrange on the teeth if a plurality of divided pieces are combined and integrated.

  Of the divided stator cores 10A and 10B to which the coils 40 are mounted in this way, the six divided stator cores 10A are arranged with the teeth 1A (first teeth) facing upward, and the remaining six divided stator cores 10B are arranged with the teeth 1B (first). (Two teeth) are arranged so as to face downward (see FIG. 1 (A)). At that time, in any of the six divided stator cores 10A and 10B, an interval corresponding to one divided stator core 10A and 10B is provided between the adjacent divided stator cores 10A and 10B. And it arrange | positions so that the division | segmentation stator core 10B which made the teeth downward may be inserted between the division | segmentation stator cores 10A which faced the teeth upward. With this arrangement, the yoke pieces 2A and 2B are combined to form a disk-shaped yoke 20 (see FIG. 1B). Thereafter, for example, a ring body (not shown) is shrink-fitted on the outer periphery of the yoke 20 to integrate all the divided stator cores 10A and 10B.

  When the stator is assembled, as shown in FIG. 2, a pair of rotors 210 and 220 is combined with the stator to constitute a motor. Each of the rotors 210 and 220 includes disk-shaped bases 211 and 221, rotating shafts 213 and 223 passing through the centers of the bases 211 and 221, and a plurality of permanent magnets 212 and 222 fixed to one surface of the bases 211 and 221. Here, four thin fan-shaped permanent magnets 212 and 222 are used for each rotor.

  Since a circular hole 110 (FIG. 1) is formed at the center of the yoke 20, the bearing portion 150 (FIG. 2) is fixed to the circular hole 110. The bearing portion 150 has a substantially cylindrical shape, and has a shaft hole 151 that supports the rotation shaft of one rotor on one end side and a shaft hole that supports the rotation shaft of the other rotor on the other end side. Although not shown, each shaft hole 151 is provided with a bearing.

  The rotors 210 and 220 are arranged on both sides of the stator, the rotation shaft 213 of one rotor 210 is fitted into one shaft hole 151 of the bearing portion 150, and the rotation shaft 223 of the other rotor 220 is fitted to the other shaft of the bearing portion 150. Fit into the hole. At that time, the permanent magnets 212 and 222 of the rotors 210 and 220 are opposed to the stator, and the rotating shafts 213 and 223 fitted in the shaft holes are independently supported by the bearing portion 150.

  By the above procedure, the rotors 210 and 220 and the stator are combined to form a motor. As shown in FIG. 3, the assembled motor has a configuration in which the rotating shafts 213 and 223 of both rotors are independent via a bearing portion 150. Although not shown in FIGS. 2 and 3, the periphery of these stators and rotors 210 and 220 is covered with a case or the like, and the ends of the rotors 213 and 223 opposite to the stator are pivotally supported by the case. Yes.

  According to the motor of this configuration, the rotors 210 and 220 can be independently rotated by individually controlling the currents flowing through the coil 4A sheathed on the first tooth 1A and the coil 4B sheathed on the second tooth 1B. Can be made. Of course, both rotors 210 and 220 can be rotated synchronously.

  In addition, since the motor can independently rotate the pair of rotors 210 and 220 using the single stator core 100, the rotation of the two rotors 210 and 220 can be controlled with a small number of parts.

  Furthermore, since the split stator cores 10A and 10B in which the teeth 1A and 1B protrude from the yoke pieces 2A and 2B are used, the coils 4A and 4B can be formed by winding the winding around the teeth 1A and 1B. Excellent winding workability of 40. In particular, in the configuration of this example, there is no part of the stator core 100 between the adjacent coils 40, so that a large winding area of the coil 40 can be secured. Usually, since a magnetic path via the yoke 20 is formed in the adjacent teeth in the first tooth 1A or the second tooth 1B, there is no problem even if a part of the stator core 100 does not exist between the adjacent coils 40. When the magnetic flux generated by the first tooth side coil 4A and the magnetic flux generated by the second tooth side coil 4B interfere in the yoke 20, the thickness of the yoke 20 may be increased.

  In addition, since the first teeth 1A and the second teeth 1B are arranged at positions that are alternately shifted in the circumferential direction of the yoke, when the rotors 210 and 220 rotate in synchronization, the rotational force of one rotor 210 (220) decreases. In doing so, a rotational force is applied to the other rotor 220 (210). Therefore, compared with the case where the first teeth 1A and the second teeth 1B are arranged at the same position in the circumferential direction of the yoke, it is possible to significantly reduce the unevenness of the motor torque.

  In addition, the above-mentioned Example can be changed suitably, without deviating from the summary of this invention, and this invention is not limited to the said Example. For example, the stator core can be replaced with a green compact, and a laminate of plate materials made of a magnetic material can be used. In addition, the first teeth and the second teeth may be provided at the same position on the front and back of the yoke.

  The axial gap motor of the present invention can be suitably used in various fields such as motors for electric vehicles and hybrid vehicles, and drive motors for industrial machines.

(A) is an exploded perspective view of a stator core used in the embodiment of the present invention, and (B) is a perspective view showing the assembled state. 1 is a schematic exploded perspective view of a motor according to an embodiment of the present invention. 1 is a schematic side view of a motor according to an embodiment of the present invention.

Explanation of symbols

100 Stator core 10A, 10B Split stator core
1A First Teeth (Teeth) 1B Second Teeth (Teeth)
20 Yoke 2A First yoke piece (yoke piece), 2B Second yoke piece (yoke piece)
30 notches
40, 4A, 4B coil
110 hole
210, 220 rotor
211, 221 Base 212, 222 Permanent magnet 213, 223 Rotating shaft
150 Bearing part 151 Shaft hole

Claims (5)

An axial gap motor in which a rotor and a stator are arranged to face each other in the axial direction of the rotation shaft,
One stator,
An axial gap motor comprising a pair of rotors arranged on both sides in the axial direction of the stator and having independent rotation axes. The stator includes a stator core and a coil made of a magnetic material,
This stator core includes a disk-shaped yoke and teeth on which a coil is sheathed,
This tooth
A first tooth that protrudes from one side of the yoke and faces one rotor;
2. The axial gap motor according to claim 1, wherein the axial gap motor includes a second tooth that protrudes toward the other surface of the yoke and faces the other rotor.   The yoke of the stator core is composed of a first yoke piece integral with the first tooth and a second yoke piece integral with the second tooth, and the first yoke piece and the second yoke piece are combined into a disk shape. 3. The axial gap motor according to claim 2, wherein   4. The axial gap motor according to claim 2, wherein the first teeth and the second teeth are arranged at positions that are alternately shifted in the circumferential direction of the yoke.   The axial gap motor according to any one of claims 2 to 4, wherein the stator core is made of a compacted body of soft magnetic powder.

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