JP2006197706A - Axial gap type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial gap type motor in which a rotor and a stator are not brought into contact with each other even in the worst case, capable of reducing misalignment of a bearing portion without increasing the thickness in a rotational axial direction when the two bearings are disposed in an inner periphery area of a pole member, and maintaining spring capability of a ring-shaped plate spring. <P>SOLUTION: This motor is constituted of the annular stator 2 and the disc rotors 8, 9 disposed so as to face each other at a prescribed gap to the common rotating shaft 4, the stator 2 is constituted of the plurality of pole members around which a coil 27 is wound around an outer periphery of teeth 51 and which are jointed in an annular condition, and the bearings 26 which are respectively disposed at right and left bearing holes 2d, 2e which are annular inner-periphery areas. Projections 2f, 2g which protrude the bearings 26 in a rotor direction are provided at the stator 2, and recesses 2d, 2e mated with the projections 2f, 2g are provided at the rotors 8, 9. Besides, a stopper is provided at the bearing hole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stator for an axial gap type electric motor, and more particularly to a bearing arrangement structure in which a plurality of pole members wound with windings are arranged circumferentially and provided in an inner circumferential space thereof.

  Conventionally, as shown in FIGS. 5 and 6, a three-phase, nine-slot axial gap type electric motor has a substantially disk-shaped stator 20 and a pair of plastic magnets arranged opposite to each other with a predetermined gap on both sides of the stator 20. The rotors 31 and 32 share the same rotor output shaft (rotary shaft) 24, and the stator 20 has a bearing portion 26 that supports the rotor output shaft 24 on the inner peripheral side thereof. It has.

  In practice, the stator 20 and the rotors 31 and 32 are housed in a bracket (housing) (not shown), and the outer periphery of the stator 20 is fixed to the bracket.

  The stator 20 includes a stator core 25 formed in an annular shape (a so-called donut shape) and a bearing portion 26 that is coaxially inserted on the inner peripheral side of the stator core 25. The stator core 25 is molded integrally with the synthetic resin 21. Has been. In this example, each bearing portion 26 includes one radial ball bearing.

  As shown in FIG. 6, the stator core 25 is configured by connecting nine pole members 25 a to 25 i in an annular shape. Each of the pole members 25a to 25i has the same shape.

  Further, as shown in FIG. 5, one pole member 25 d includes a tooth (iron core) 51 formed by laminating a plurality of metal plates in a trapezoidal shape. An insulator 50 made of synthetic resin is integrally formed.

  The insulator 50 is generally formed in a bobbin shape having an H-shaped cross section including substantially fan-shaped flanges 52 and 53 arranged as a pair of left and right along both side surfaces of the tooth 51. The coil 27 is wound between the flanges 52 and 53.

  And after forming the pole member unit for 3 phases, as shown in FIG. 6, the pole member for U phases is arrange | positioned sequentially at circular arc shape. Then, the pole members of the V phase and the W phase are arranged next to each other in an arc shape, and both the pole members are connected to each other. As a result, nine pole members are assembled in an annular shape.

  Ua and Ub are U-phase lead wires, Va and Vb are V-phase lead wires, and Wa and Wb are W-phase lead wires, and are resinous for holding each lead wire in the stator core 25. This is connected to a drive circuit board for an electric motor (not shown) through the holder 30.

Then, the outer peripheral portion and inner peripheral portion of each pole member and the lead wire holding body 30 are hardened with the synthetic resin 21 by insert molding. Thereafter, the bearing portions 26 are press-fitted into the left and right inner peripheral sides of the stator core 25 to create the stator 20 (see, for example, Patent Document 1).
Note that a ring-shaped leaf spring 33 having a corrugated cross section is disposed between one inner peripheral side of the stator core 25 and the bearing portion 26, and prevents the rotor output shaft 24 from sliding in the axial direction. It has become.

  In addition, as in the conventional example described above, a stator having teeth on a pole member requires a certain amount of thickness in the rotational axis direction on the teeth itself, and as a result, the inner circumference of the pole member arranged in a circular shape. A bearing part can be arrange | positioned in space. As described above, the axial gap type electric motor is characterized in that the thickness in the rotation axis direction can be reduced, and the bearing portion is arranged on the inner periphery of the stator, not the structure in which the bearing is held at both ends of the bracket like the radial gap type electric motor. The structure is common.

However, when the bearing portion is disposed on the inner periphery of the stator, the two bearing portions are close to each other, and the closer the bearing portions are, the more the rotor rotates due to the slight misalignment of the shaft centers of the two bearing portions. There was a problem that vibration sometimes occurred.
In addition, the ring-shaped leaf spring has a structure that suppresses the sliding of the rotor output shaft in the axial direction. In some cases, the rotor and the stator may come into contact with each other.

Japanese Patent Laying-Open No. 2004-282899 (page 9-12, FIG. 1)

  The present invention solves the above-described problems and reduces the axial misalignment of the bearing portion without increasing the thickness in the rotation axis direction when two bearing portions are arranged in the inner circumferential space of the pole member. It is an object of the present invention to provide an axial gap type electric motor and an axial gap type electric motor in which a ring-shaped leaf spring does not lose its spring property and the rotor and the stator do not contact at worst.

In order to solve the above-mentioned problems, the present invention includes a ring-shaped stator and a disk-shaped rotor that are arranged opposite to each other with a predetermined gap on the same rotation shaft,
The stator is composed of a plurality of pole members in which a coil is wound around the outer periphery of a tooth and connected in an annular shape, and bearing portions respectively disposed in left and right bearing holes which are ring-shaped inner peripheral spaces. In the axial gap type motor
A recess is provided in the vicinity of the inner periphery of the side surface of the rotor facing the stator, and the bearing portion protrudes into the recess.

  Further, the stator has a structure in which a plurality of the pole members connected in an annular shape and a protruding portion that holds the outer periphery of the protruding bearing portion are integrally formed of a synthetic resin.

  The rotor has a structure in which a permanent magnet is disposed on a surface corresponding to the teeth of a circular steel plate, and the concave portion is provided near the inner periphery of the permanent magnet.

In addition, a ring-shaped stator and a disk-shaped rotor, which are opposed to each other with a predetermined gap on the same rotation shaft,
The stator is composed of a plurality of pole members in which a coil is wound around the outer periphery of a tooth and connected in an annular shape, and bearing portions respectively disposed in left and right bearing holes which are ring-shaped inner peripheral spaces. In the axial gap type motor
A stopper for restricting sliding of the rotor in the rotation axis direction is provided on the surface of the stator in the rotation axis direction forming the bearing hole, and the rotor is disposed between the bearing hole and the bearing portion. A structure is provided in which pressing means for pressing in the direction opposite to the stopper is provided.

By using the above means, according to the axial gap type electric motor according to the present invention,
The invention according to claim 1 has a structure in which a recess is provided in the vicinity of the inner periphery of the side surface of the rotor facing the stator, and the bearing portion protrudes into the recess.
The distance between the two bearing parts in the direction of the rotation axis can be increased, the positional deviation of the axis of the bearing part can be reduced, and the distance between the two bearing parts in the direction of the rotation axis can be increased. It is not necessary to increase the thickness in the direction of the rotation axis, and the motor can be miniaturized.

According to a second aspect of the present invention, the stator has a structure in which a plurality of pole members connected in an annular shape and a protruding portion that holds the outer periphery of the protruding bearing portion are integrally formed of a synthetic resin. ,
It is easy to widen the distance between the two bearing parts in the direction of the rotation axis, and the shaft core can be accurately adjusted, so that the positional deviation of the shaft core of the bearing part can be reduced, and the rotation blur of the rotor can be reduced. Can do.

In the invention according to claim 3, the rotor has a structure in which a permanent magnet is disposed on a surface corresponding to the teeth of the circular steel plate, and a recess is provided in the vicinity of the inner periphery of the permanent magnet.
A space is provided near the inner circumference of the permanent magnet of the rotor that has a relatively small effect on the performance of the motor, and a portion of the stator can be placed in this space to reduce the thickness of the entire motor in the direction of the rotation axis, enabling downsizing. Become.

According to a fourth aspect of the present invention, a stopper for restricting the sliding of the rotor in the rotation axis direction is provided on the surface of the stator in the rotation axis direction forming the bearing hole, and the rotor is stopped between the bearing hole and the bearing portion. By having a structure provided with pressing means to press in the opposite direction,
When a large movement in the rotation axis direction due to sliding occurs while maintaining the spring property of the pressing means, the permanent magnet can be prevented from coming into contact with the teeth.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail as examples based on the attached drawings. The same parts as those in FIGS. 4 to 5 described in the background art are assigned the same reference numerals, and detailed description thereof is omitted.

  A feature of the present invention is that, in an axial gap type electric motor having a small thickness in the rotation axis direction, in order to reduce axial misalignment of the bearing portion, a rotor and a stator for increasing the interval in the rotation axis direction of a plurality of bearings to the maximum. In the structure. A structure for this will be described below.

  As shown in FIG. 1, a three-phase, nine-slot axial gap type motor 1 according to the present invention includes a substantially disc-shaped stator 2 and a pair of rotors 8 that are opposed to each other with a predetermined gap on both sides of the stator 2. 9, the rotors 8 and 9 share the same rotor output shaft (rotary shaft) 4, and the stator 2 is coaxially inserted on the inner peripheral side thereof and supports the rotor output shaft 4. 26. In this example, each bearing portion 26 includes one radial ball bearing.

  The electric motor includes a bracket lid 15, a printed circuit board 14 mounted with a motor drive circuit, a rotor 8, a stator 2, a rotor 9, and a bracket lid 16, which are each circular around the rotor output shaft 4. It is installed.

  A hall element 14c is arranged on the printed circuit board 14 facing the permanent magnet 8c for detecting the position of the rotor 8, and the rotational position of the rotor 8 is detected. In addition, the winding connection terminal 11 a of the connection body 11 is soldered near the outer periphery of the printed circuit board 14, and the lead wire of the coil 27 of the stator 2 is connected to the printed circuit board 14 through the connection body 11. ing.

  The bracket lids 15 and 16 are formed by pressing a steel plate and are structured to be fitted to both sides of the stator 2. As a matter of course, whether or not to attach the bracket lids 15 and 16 should be determined by the specifications of the electric motor.

  On the other hand, the stator 2 is formed by integrally molding a stator core 5 in which nine pole members each having a coil 27 wound around an insulator 10 applied to a tooth 51 are arranged in a ring shape (so-called donut shape) with a synthetic resin 7. Is formed. At that time, the stator 2 is formed by integrally molding the synthetic resin 7 so that the bearing hole 2 d for holding the bearing portion 26 and the bearing hole 2 e are concentric with the rotor output shaft 4.

On one side surface of the stator 2, there is a projecting portion 2f in which a bearing hole 2d and a bearing portion 26 disposed therein are projected toward the rotor 8, and on the other side surface, a bearing hole 2e and its bearing hole 2e. Protrusions 2g obtained by projecting the bearings 26 disposed inside toward the rotor 9 are molded integrally with the synthetic resin 7, respectively. These protrusions hold the outer periphery of the bearing hole, and can securely hold the bearing portion on the stator and can accurately align the shaft centers of the two bearing portions. Since the axial interval can be increased as compared with the conventional electric motor shown in FIG. 5 that does not include the projecting portions 2f and 2g, the axial misalignment of the bearing portion 26 can be reduced, and the rotation of the rotor can be reduced. Blur can be reduced.

The rotor 8 includes a fan-shaped permanent magnet 8b in a ring shape on one surface of the back yoke 8a made of a circular steel plate facing the stator core 5, and a position detecting permanent magnet 8c on the other surface. . The rotor 9 is provided with a fan-shaped permanent magnet 9b in a ring shape on one surface facing the stator core 5 of a back yoke 9a made of a steel plate. As a result, a concave portion 8d and a concave portion 9d, which are cylindrical spaces having the same thickness as those permanent magnets, are formed near the inner circumferences of the permanent magnet 8b and the permanent magnet 9b. Further, the projecting portions 2f and 2g are arranged in the spaces of these concave portions.
The concave portion is not limited to this embodiment, and may be provided on a plastic magnet in which the back yoke and the permanent magnet are integrated, or the concave portion is further extended on the back yoke itself in this embodiment. Also good.

  Thus, by providing a space in the vicinity of the inner periphery of the permanent magnet of the rotor that has a relatively small influence on the performance of the motor and arranging a part of the stator including the bearing portion in this space, the rotation axis direction of the entire motor can be reduced. Since the thickness can be reduced, the size can be reduced.

Furthermore, by providing recesses 8d and 9d in the vicinity of the inner circumferences of the side surfaces of the rotors 8 and 9 facing the stator 2, the bearing portion 26 is disposed so as to protrude into the recesses 8d and 9d. ,
In order to reduce the positional misalignment of the shaft core of the bearing portion by increasing the interval in the rotation axis direction of the two bearing portions, and to increase the interval in the rotation axis direction of the two bearing portions, Since it is not necessary to increase the thickness in the direction, the electric motor can be downsized.

  As illustrated in FIG. 2, the stator core 5 is configured by connecting nine pole members 5 a to 5 i in an annular shape. Each of the pole members 5a to 5i has the same shape except for the connection body 11 that electrically connects and connects the windings fixed to 5a, 5d, and 5g.

  As shown in FIG. 1, the pole member 5e includes a tooth (iron core) 51 formed by laminating a plurality of metal plates in a trapezoidal shape, and the teeth 51 are made of a synthetic resin except for both side surfaces thereof. The insulator 10 is integrally formed.

  The insulator 10 is generally formed in a bobbin shape having an H-shaped cross section including substantially fan-shaped flanges 12 and 13 arranged as a pair of left and right along both side surfaces of the tooth 51.

  An arbitrary pole member, for example, in the case of the U phase, a connection body 11 in which L-shaped winding connection terminals 11a are fixed to the left and right ends on the surface of the flange 12 behind the pole member 5d (the outer peripheral side when the stator is formed). Wear. Then, the coil winding end of the pole member 5e, that is, the U-phase winding terminal end Ub is connected to the one winding connection terminal 11a protruding in the horizontal direction and soldered, and the U-phase is connected to the other winding connection terminal 11a. The winding start end Ua of is wound and soldered.

  After forming the pole member unit for three phases in this way, as shown in FIG. 2, the pole member for the U phase is arranged in an arc shape, next to the V phase, and next to the W phase. These pole members are arranged in a circular arc shape, and both adjacent pole members are connected to each other. As a result, nine pole members are assembled in an annular shape.

  As shown in the perspective view of FIG. 3, the outer peripheral portion of each pole member, the inner peripheral portion including the bearing hole 2d and the bearing hole 2e, and the lead wire connection body 11 are solidified with synthetic resin by insert molding. The stator 2 is created. After that, the bearing portions 26 are respectively press-fitted into the bearing holes 2d and the bearing holes 2e provided on the left and right inner peripheral sides of the stator core 2 to create the stator 2.

4A and 4B are cross-sectional views of the main part showing the periphery of the bearing portion of the stator according to the present invention. FIG. 4A shows an example of a rectangular stopper, and FIG. 4B shows an example of a convex stopper according to another embodiment. .
In FIG. 4A, a ring-shaped leaf spring 33 having a corrugated cross section is arranged between the bottom surface of the bearing hole 2d of the stator core 2 made of insert-molded resin 7 and the bearing portion 26. The rotors 8 and 9 and the rotor output shaft 4 are pressed in the left axial direction in FIG.

Further, a stopper 2c for restricting sliding of the rotors 8 and 9 and the rotor output shaft 4 in the right rotation axis direction in FIG. 1 is provided by insert molding. This stopper 2 c is formed as a rectangular protrusion on the outer periphery of the bottom surface of the bearing hole 2 d of the stator 2.
In this embodiment, when the rotor diameter is 76 mm, the rotor interval is 27 mm, the bearing diameter is 22 mm, and the bearing thickness is 8 mm, the thickness of the stopper 2c in the direction of the rotor output shaft 4 is 2 mm.

  Further, as a modification of the stopper 2c of FIG. 4A, there is a structure of a stopper 2c 'shown in FIG. The stopper 2 c ′ is formed in a triangular shape on the outer periphery of the bottom surface of the bearing hole 2 d of the stator 2. By forming the stopper 2c ′ in a triangular shape in this way, when the ring-shaped leaf spring 33 is mounted in the bearing hole 2d, there is no need to worry about the rotational position of the ring-shaped leaf spring 33. , Workability is improved.

  That is, in the rectangular stopper 2c shown in FIG. 4 (A), the wave-shaped cross section of the ring-shaped leaf spring 33 must be disposed so as to straddle the stopper 2c at the time of mounting, but FIG. When the stopper 2c ′ shown in FIG. 2 is mounted, if the corrugated cross section is arranged in an arbitrary rotation direction without being aware of the corrugated cross section, the corrugated cross section slides down with the triangular inclination of the stopper 2c ′, resulting in a ring. This is because the corrugated cross-sectional portion of the plate spring 33 is disposed so as to straddle the stopper 2c ′.

  As described above, the stopper 2c that restricts the sliding of the rotor in the rotation axis direction is provided on the surface of the stator 2 that forms the bearing hole 2d in the direction of the rotor output shaft 4 (rotation axis), and the bearing hole 2d and the bearing portion 26 are provided. If the structure is provided with a ring-shaped leaf spring 33 as a pressing means for pressing the stator 2 in the direction opposite to the stopper 2c, the stopper 2c keeps the spring property of the leaf spring 33 while sliding. When a large movement in the direction of the rotor output shaft 4 due to the movement occurs, the permanent magnets 8 b and 9 b can be prevented from coming into contact with the teeth 51. The pressing means may not be a ring-shaped leaf spring but may be replaced by a spring or the like.

  The stator 2 includes a step portion 2a to which the bracket lid 15 is fitted and a step portion 2b to which the vicinity of the outer periphery of the printed board is fitted. In addition, after the insert molding, the winding connection terminal 11a and the board positioning boss 11c of the connection body 11 are exposed.

  Then, the winding connection terminal 11 a protruding in the vertical direction of the connection body 11 is inserted into the hole 14 a of the printed board 14 on which the drive circuit for the electric motor is mounted, and is soldered to the land pattern of the printed board 14. At the same time, the board positioning boss 11c of the connection body 11 and the notch 14b of the printed board 14 are fitted.

  The present invention is not limited to the three-phase nine-slot motor described above, and can be widely applied to a three-phase 12-slot motor, an axial gap type motor having two or more bearing portions on the stator, and the like.

  Further, in the present embodiment, the rotors 8 and 9 share the same rotor output shaft 4, but may be a two-output shaft type in which each rotor 8 and 9 has a rotor output shaft. Moreover, the electric motor provided with only one rotor may be sufficient.

It is sectional drawing which shows the Example of the axial gap type motor by this invention. It is a perspective view which shows the stator core by this invention. It is a perspective view which shows the stator and drive printed circuit board by this invention. It is principal part sectional drawing showing the bearing part periphery of the stator by this invention, (A) is a rectangular stopper, (B) is an example which showed the triangular stopper, respectively. It is sectional drawing which shows the conventional axial gap type motor. It is a top view which shows the stator of the conventional axial gap type motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axial gap type electric motor 2 Stator 2a, 2b Step part 2c, 2c 'Stopper 2d, 2e Bearing hole 2f, 2g Protrusion part 4 Rotor output shaft (rotary shaft)
5 Stator core 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i Pole member 7 Synthetic resin 8 Rotor 8a Back yoke 8b Permanent magnet 8c Permanent magnet 8d Recess 9 Rotor 9a Back yoke 9b Permanent magnet 9d Recess 10 Insulator 11 Wiring member 11a Winding connection terminal 11c Board positioning boss 12 Flange 12a Hole 14 Printed circuit board 14a Hole 14b Notch 14c Hall element 15 Bracket lid 16 Bracket lid 26 Bearing (radial ball bearing)
33 Ring-shaped leaf spring (pressing means)
27 Coil 51 Teeth

Claims (4)

Including a ring-shaped stator and a disk-shaped rotor that are arranged opposite to each other with a predetermined gap on the same rotating shaft,
The stator is composed of a plurality of pole members in which a coil is wound around the outer periphery of a tooth and connected in an annular shape, and bearing portions respectively disposed in left and right bearing holes which are ring-shaped inner peripheral spaces. In the axial gap type motor
An axial gap type electric motor, wherein a recess is provided in the vicinity of the inner periphery of the side surface of the rotor facing the stator, and the bearing portion protrudes into the recess.   2. The stator according to claim 1, wherein the stator includes a plurality of the pole members that are connected in an annular shape and a protruding portion that holds the outer periphery of the protruding bearing portion, and is integrally formed of a synthetic resin. Axial gap type electric motor.   3. The rotor according to claim 1, wherein a permanent magnet is disposed on a surface of the rotor corresponding to the teeth of the circular steel plate, and the concave portion is provided near an inner periphery of the permanent magnet. Axial gap type electric motor. Including a ring-shaped stator and a disk-shaped rotor disposed opposite to each other with a predetermined gap on the same rotation axis;
The stator is composed of a plurality of pole members in which a coil is wound around the outer periphery of a tooth and connected in an annular shape, and bearing portions respectively disposed in left and right bearing holes which are ring-shaped inner peripheral spaces. In the axial gap type motor
A stopper for restricting sliding of the rotor in the rotation axis direction is provided on the surface of the stator in the rotation axis direction forming the bearing hole, and the rotor is disposed between the bearing hole and the bearing portion. An axial gap type electric motor comprising pressing means for pressing in a direction opposite to the stopper.

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