JP2004357404A - Eccentric rotor and axial direction gap type brushless oscillation motor provided therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a very thin and small-sized brushless oscillation motor which can obtain sufficient strength as a silent informing source for portable equipment. <P>SOLUTION: The eccentric rotor R is provided with an axial direction gap type magnet 8, a thin yoke plate 6 for receiving the magnet field of the magnet, and an eccentric weight 9 with ≥ 17 of the specific gravity at least whose part is arranged to the outside of the magnet. A tongue piece 6c is provided to a part of the outer periphery of the thin yoke plate. A recessed part 9a to be engaged to the tongue piece is provided to the eccentric weight. The eccentric weight is fixed by utilizing the recessed part and the tongue piece. It is axially supported by a bearing 7 via a metal member 6b provided to the inner diameter side of the magnet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an axial gap type brushless motor suitable for use as a silent notification means of a mobile communication device and having a drive circuit member built therein.
[0002]
[Prior art]
A brushless motor requires a driving circuit in place of a brush and a commutator, but the above-mentioned conventional structures do not have a built-in driving circuit and usually require four or more lead-out terminals for external attachment. There is a problem that it cannot be handled like the two-terminal DC motor.
Moreover, in a normal brushless motor, the stator has a plurality of armature coils arranged evenly over the entire circumference, and the drive circuit device requires other electronic components such as an IC. Then it wasn't very built-in.
The present applicant has previously proposed a flat axial gap type brushless vibration motor which is a coreless slotless type and does not incorporate a drive circuit member. (See Patent Documents 1 and 2)
As a brushless vibration motor with a drive circuit, a cored type, a cored type in which an armature coil is wound around a plurality of equally arranged salient poles, and a non-circular type in which a drive circuit member is arranged on the side of the stator. Things are known. (See Patent Document 3)
However, such a type has a large size in the lateral direction, and the mounting efficiency of the SMD method on a printed wiring board in which the set is inferior is poor. There is no sex.
Therefore, the applicant of the present invention has previously prepared a cored, slotless coreless type including a part of a plurality of armature coils, and provided a space, and provided a drive circuit member in this space. is suggesting. (See Patent Document 4)
[0003]
[Patent Document 1] Japanese Utility Model Laid-Open No. 4-137463 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-143767 [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-245103 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-142427 (FIG. 8 to 11)
[0004]
[Problems to be solved by the invention]
In addition, when such a vibration motor is mounted on a mobile communication device such as a mobile phone, the size is required to be extremely thin and downsized, and an eccentric rotor having a shaft of 0.6 mm or less has to be adopted. Therefore, it is necessary to give due consideration to impact resistance.
In addition, it is necessary to use a coreless slotless type with a gap in the axial direction in order to achieve a reduction in thickness. However, if the magnetic force of the magnet is not controlled, the loss of adsorption to the stator is large, and starting is difficult.
Also, in order to secure the amount of vibration, an eccentric rotor equipped with the highest class high specific gravity tungsten alloy is required as the size becomes smaller in order to obtain eccentricity.However, as the content of tungsten with a high melting point increases, the laser welding increases. There is a new problem that makes it difficult.
The object of the present invention is not to use laser welding in distributing the eccentric weights, even when using a resin magnet containing a rare earth powder whose magnetic force can be easily controlled, for example, by means such as brazing or bonding. The impact resistance is improved by devising the shape of each member, and the axial gap type brushless vibration motor of FIGS. 8 to 11 of JP-A-2002-142427 disclosed in Patent Document 4 is improved. The thin and simple structure provides sufficient strength while reducing the thickness of each member, enables the drive circuit components to be built-in, and can be handled in the same manner as ordinary DC motors, making it an extremely useful source of silent information for portable devices. It is intended to provide a thin small brushless vibration motor.
[0005]
[Means for Solving the Problems]
In order to solve the above problem, as set forth in claim 1, an axial gap magnet (8, 88) having a plurality of magnetic poles, a thin yoke plate (6, 66) receiving a magnetic field of the magnet, An eccentric weight (9) having a specific gravity of 17 or more, at least partially disposed outside the magnet, is provided, and the thin yoke plate is provided with a tongue piece (6c) on a part of the outer periphery. The eccentric weight is provided with a recess (9a) that engages with the tongue, and is fixed to the outer periphery of the thin yoke plate using the recess and the tongue. Can be achieved by supporting the shaft via the metal members (6b, 8a) provided in the above. With this configuration, the eccentric weight can sufficiently withstand the impact in the axial direction and the radial direction, and the axial gap type magnet can be strongly supported by the metal member via the thin yoke plate.
Specifically, as in the invention as set forth in claim 2, the thin yoke plate has a thickness of 0.2 mm or less, and a flat portion (6h) receiving the magnetic field of the magnet and an outer diameter side for fixing the eccentric weight. There is a hanging part (6a) and an inner diameter side hanging part (6b) for supporting the shaft, and a part of the tongue piece is protruded outward in the horizontal direction integrally with the outer diameter side hanging part, and a flange (6d) is provided. It is preferable that the protrusion protrudes inward in the horizontal direction from the inner diameter side hanging portion, the tongue piece is fitted into the recess, an eccentric weight is mounted, and the metal member is supported by the inner diameter side flange.
In this way, the overall thickness of the eccentric weight is not sacrificed, so that the weight of the eccentric weight fluctuates little, and the fixing strength of the magnet is obtained.
Another specific means is that the means for supporting the shaft is engaged with the bearing (7, 77) by caulking (6e) or press-fitting (6f). In this way, even an oil-impregnated bearing that cannot be bonded can be easily supported.
2. The eccentric rotor according to claim 1, wherein said shaft supporting means is adapted to engage a part of said inner diameter side hanging portion with said shaft (2) by welding (L2).
Further, the shaft supporting means can be a shaft rotating vibration motor if a part of the inner diameter side hanging portion is engaged with the shaft (2) by welding (L2).
Further, another metal member (8a) is fixed to at least the thin yoke plate on the inner diameter side of the axial gap type magnet, and the shaft is supported via this metal member. It is suitable when the metal member is reinforced at the time of shaft support to be a fixed shaft type. As shown in claim 6, the shaft supporting means welds (Y) or press-fits a part of the inner diameter side hanging portion. If the shaft is engaged with the shaft (22), a shaft-rotating type can be obtained.
Further, if the eccentric weight is brazed to the tongue piece (6c) of the thin yoke plate in the recess (9a), the eccentric weight does not increase the overall thickness. Sufficient fixing strength can be obtained.
The tongue piece (6c) and the recess (9a) of the eccentric weight cooperate with each other to restrict radial movement, and the eccentric weight is bonded to the eccentric weight. And the axial gap magnet is adhered to the thin yoke plate using each hanging portion, or as a locking portion at at least two places on the outer diameter side hanging portion of the thin yoke plate. A notch (6g) is provided so as to be substantially opposed, and a projection (9b) formed on the eccentric weight is inserted into the notch. The eccentric weight includes the recess (9a) and the projection. If the eccentric weight is fixed to the outer diameter side hanging part by using the part, the eccentric weight can be securely fixed to the thin yoke plate, and movement in the radial direction and the axial direction is hindered, so that the impact resistance even with adhesion is We can expect enough.
[0006]
Furthermore, in order to provide an axial gap type brushless vibration motor having such an eccentric rotor, as described in claim 10, the eccentric rotor (R, R1) according to any one of claims 1 to 9 is provided. , R2, R3, and R4), a yoke bracket (1) for rotatably supporting the eccentric rotor via a shaft, the yoke bracket being centered on a shaft support (1a, 11a), and a periphery of the shaft support. And a plurality of air-core armature coils (5A, 5B, 55A, 55B and 55c) disposed on the stator base.
By doing so, an axial gap type motor having a thin rotor portion can be obtained. The thickness of the drive circuit member and the thickness of the bracket can be neglected.
In order to obtain an axial gap type brushless motor having a built-in beating firing, a support (1b) extending radially integrally with the shaft support and a cavity (1e) are provided in the support. The stator base (3) is made of a flexible substrate, and has a thickness within the air-core armature coil in a space where the plurality of air-core armature coils are not arranged. As described above, a part (D, D1) of the drive circuit member is preferably arranged on the stator base. In this case, the thickness of the drive circuit member and the thickness of the bracket can be ignored.
Specifically, as shown in claim 12, a part of the drive circuit member is disposed in the space (1e) in plan view, and at least a stator base at a position where the part of the drive circuit member is disposed. If a part of the stator base fits within the thickness of the bracket (1), the substantial thickness of the stator base can be ignored.
In order to obtain a fixed shaft type motor, the yoke bracket has a thickness of 0.2 mm or less, a base end of the shaft (2) is fixed at the center, and a resin is provided at least in the space (1e). (4) is integrated, the eccentric rotor is rotatably mounted on the shaft (2) via a bearing (7), and the tip of the shaft is fitted into the central recess (10a) of the cover member (10). Preferably, the yoke bracket has a thickness of 0.2 mm or less and a bearing (77) is provided on a central shaft support portion (11a). Resin is integrated with at least a part of the space (1e), and the shaft (22) is supported at the tip end on the inner diameter side of the thin yoke plate, and the base end of the shaft is located at the bottom of the shaft support. It should be pivot-supported.
According to a fifteenth aspect of the present invention, the stator base (33) is disposed under the yoke bracket, and the drive circuit member has a space (1e) including the support portion (1b) and the holding portion (1c). And may be integrally formed of resin (4) including the air-core armature coil.
In each of these configurations, the thickness of the drive circuit member can be ignored, so that an extremely low-profile motor can be obtained.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a plan view showing a first embodiment of the eccentric rotor of the present invention.
FIG. 2 is a vertical sectional view taken along line AA of FIG.
FIG. 3 is a plan view of a modification of FIG.
FIG. 4 is a longitudinal sectional view showing a second embodiment of the eccentric rotor of the present invention.
FIG. 5 is a longitudinal sectional view of a fixed shaft type air gap type 1-hole sensor type coreless slotless type brushless motor in which the eccentric rotor of FIG. 1 is stored, and the eccentric rotor is cut along line AA of FIG. .
FIG. 6 is a plan view on the stator side in FIG. 5 of FIG.
FIG. 7 is a plan view of one member of FIG.
FIG. 8 is a sectional view of a modification of FIG.
FIG. 9 is a cross-sectional plan view of a coreless slotless brushless vibration motor of a sensorless type of a fixed shaft type having an eccentric rotor according to the present invention.
FIG. 10 is a longitudinal sectional view of FIG.
FIG. 11 is a plan view of one member of FIG.
FIG. 12 is a longitudinal sectional view of a shaft-rotation type axial gap type brushless vibration motor containing an eccentric rotor according to an embodiment of the present invention.
[0008]
Hereinafter, a configuration of the present invention will be described based on each of the illustrated embodiments.
In the eccentric rotor R shown in FIGS. 1 and 2, an axial gap type resin magnet 8 in which rare earth magnet powder is integrated with a polyamide resin is bonded to a thin yoke plate 6. The thin yoke plate 6 has a flat portion 6h for receiving a magnetic field of the axial gap resin magnet 8, an outer diameter side hanging portion 6a and an inner diameter side hanging portion 6b integrated with the flat portion 6h. Since the magnet 8 surrounds the air gap type resin magnet 8, a strong adhesive force is obtained. As shown in FIG. 5, the inner diameter side hanging portion 6b is further hung from the thickness of the axial gap type resin magnet 8, and the sintered oil-impregnated bearing 7 is attached thereto by laser welding L2. That is, the inner diameter side hanging portion 6b functions as a welding metal member as the inner diameter side of the axial gap resin magnet 8.
In this thin yoke plate 6, two tongue pieces 6c are integrally protruded from the outer diameter side hanging portion 6a at a predetermined opening angle in the normal direction in the horizontal direction, and the tongue pieces are interposed between them at about 180 degrees. A notch 6d that opposes and functions as a locking portion is formed.
The arc-shaped eccentric weight 9 has a recess 9a to be received by the tongue piece 6c formed at the position of the tongue piece 6c on one surface side, and a projection 9b to be inserted into the notch 6d at both ends is provided. The recess 9a and the projection 9b are fixed to the outer diameter side hanging portion 6a of the thin yoke plate 6 by bonding or the like while fitting the tongue piece 6c and the notch 6d into the outer diameter side hanging portion 6a. Since the tongue piece 6c is formed in two normal directions, the radial movement of the eccentric weight 9 is restricted.
Although not shown, the protrusion may be further extended inward so as to bite into a recess formed in the magnet.
In this way, the movement can be more restricted in the radial direction.
Accordingly, the eccentric weight 9 is restricted from moving in the axial direction and the radial direction by the tongue piece 6c, the adhesive is surely wrapped around by the notch 6d, and the movement in the radial direction is restricted. Will be.
[0009]
In order to restrict the radial movement of the eccentric weight as the above-described deformation, a combination of a tongue piece 66c having a hook k at the tip and a recess 99a having the same shape as shown in FIG. You may.
FIG. 4 shows a second embodiment of the eccentric rotor according to the present invention. That is, the thin yoke plate is made of magnetic stainless steel and is thin, having a thickness of 0.1 mm. There is an outer diameter side hanging part 6a for fixing the weight, and an inner diameter side hanging part 6b for supporting the shaft. A part of the tongue piece 6c is projected outward in the horizontal direction integrally with the outer diameter side hanging part 6a. A flange 6d protrudes inward in the horizontal direction from the inner diameter side hanging portion 6b, the recess 9a is fitted into the tongue piece 6c, and an eccentric weight 9 is provided. A flange is attached to the inner diameter side flange 6d as the metal member. The sintered oil-impregnated bearing 77 is attached by caulking. In this way, the eccentric weight is fixed by brazing or bonding the recess 9a and the tongue piece 6c, and the magnet is bonded or bonded by spot welding in the case of a rare earth sintered metal magnet. It can be easily configured as the rotor R2.
[0010]
The structure of such a shaft-fixed, axially-spaced, coreless, slotless, Hall-sensor-type, brushless vibration motor that houses such an eccentric rotor R is as shown in FIGS. 5, 6, and 7. FIG. That is, the yoke bracket 1 is made of a stainless steel plate having a weaker magnetic property than an iron plate and has a thin thickness of 0.1 mm to 0.2 mm, and has a shaft bearing 1a protruding in a burring shape at the center thereof. A ring-shaped reinforcement is provided by a detent torque generating portion 1b as a support made of a magnetic material that receives a magnetic field of an axial field magnet (described later) extending at an angle of three degrees and further extending in the radial direction. It has a holding part 1c which also serves as a part, and a part of this holding part is further protruded in the radial direction to form a power supply terminal mounting part 1d. The yoke bracket 1 forms a non-magnetic space 1e between the detent torque generating portions 1b in order to stop magnetic poles of an axial field magnet described later at a specific position. In the drawing, reference numeral 1f designates a mounting leg 1f further protruding outward from the holding portion 1c so that reflow soldering can be directly performed on a printed wiring board or the like on the device side.
On the upper surface of the yoke bracket 1 configured as described above, a thin shaft 2 of about 0.5 mm is press-fitted into the shaft support portion 1a at a base end, and a flexible printed wiring board stator base 3 is mounted around the shaft. Is placed.
On the stator base 3, two wound-type air-core armature coils 5A and 5B are placed facing each other and connected in series so as to be single-phase.
A drive circuit device including one Hall sensor H and a drive circuit member D formed as an IC is disposed on the stator base between these wound-type air-core armature coils 5A and 5B.
Here, the positional relationship between the detent torque generator 1b and the single-phase air-core armature coil is such that the effective conductor of the air-core armature coil is set in accordance with the magnetic poles of the magnet described later, and the shape of the detent torque generator 1b is a magnet. It is preferable to set so that the minimum stopping torque can be obtained in all postures when stopping by the magnetic force. With this configuration, each of these stator members has no air-core armature coil or the like superimposed in a plan view, and can be configured to be thin.
Here, the position where the drive circuit member of the stator base 3 is mounted is set not in the detent torque generating portion 1b but in the space 1e, so that the stator base 3 made of the flexible printed wiring board escapes into this space. Therefore, the thickness of the stator base 3 in this portion can be ignored.
The stator thus constructed is integrally molded with the resin 4 together with other members.
Therefore, even if the yoke bracket 1 is thin, the integrated member serves as a skeleton and the strength is reinforced, so that the entire stator side can be reinforced.
In the figure, reference numeral 1g denotes a projection for determining the position of the stator base and preventing detachment of the yoke bracket and the resin when integrally molded with the resin.
Here, the axial gap resin magnet 8 constituting the eccentric rotor R is magnetized with six poles alternately with NS, and the driving principle thereof is known, so that the description thereof is omitted.
In storing the eccentric rotor R, the eccentric rotor R is rotatably mounted on the shaft 2 via at least two laminated thrust washers S1 to reduce brake loss. Thereafter, a shallow cap-shaped cover member 10 made of a thin non-magnetic stainless material is covered, and the tip of the shaft is fitted into a shaft mounting hole 10a formed in the center of the cover member 10 via a thrust washer S2. Here, the tip of the shaft mounting hole is thinner than the shaft diameter, so that the tip of the shaft 2 does not protrude. At the same time as welding Y, the opening of the cover member 10 is assembled to the holding portion 1c of the yoke bracket 1 by laser spot welding Y.
Therefore, since a monocoque structure is assembled by welding in this manner, sufficient strength can be obtained even when a thin member is used.
By storing a stator-side member including the winding armature coils 5A and 5B, the Hall sensor H, the drive circuit member D, and the like provided on the stator base 3 inside the cover member 10, a power supply terminal mounting portion is provided outside the motor. Since it is only necessary to derive a pair of power supply terminals from 1d, the brushless motor can be handled in the same manner as a normal motor. If the cover is made of non-magnetic austenitic stainless steel, it has a heat insulating effect and can withstand reflow.
[0011]
Next, a second embodiment of the axial gap type vibration motor will be described with reference to FIG. 8, but the only difference from FIG. 2 is the eccentric rotor R3. Alternatively, substantially the same members having the same functions are denoted by the same reference numerals, and description thereof will be omitted.
Here, the eccentric rotor R3 enlarges the inner diameter by using the magnetized dead space of the axial gap magnet 88, and attaches a ring-shaped metal member 8a such as brass to the space between the inner diameter side hanging portion 6b and the bearing 7. The flange 6 integral with the inner diameter side hanging portion 6b is further press-fitted on the inner diameter side into the sintered oil-impregnated bearing 7, so that the metal member 8a is reinforced. The ring-shaped metal member 8a such as the brass may be disposed on the thin yoke plate 66 by welding, bonding, or the like. Depending on the size of the bearing, the bearing may be supported by welding instead of press-fitting.
[0012]
9, 10, and 11 show the characteristics of a coreless slotless brushless vibration motor of a fixed shaft type, axial gap type sensorless type, that is, the yoke bracket 11 is made of stainless steel having weak magnetism. FIG. 8 shows a shaft bearing 1a having a thickness of about 0.17 to 0.2 mm made of a plate and having a thin shaft 2 having a thickness of 0.5 mm protruding in the center in a burring shape and press-fitted at its base end. The shaft 11b extending from the shaft bearing 1a in the radial direction and the ends of the shafts 11b extending in the radial direction are integrally connected to the shaft 11b to reinforce the shaft 11b. A ring-shaped holding portion 1c also serving as an assembling portion is formed, and a part of the holding portion is further protruded in the radial direction to form a power supply terminal mounting portion 1d.
The holding portion 1c is formed so as to be one step downward with respect to the shaft support portion 1a and the support 11b. Flexible printing is performed on the lower portion of the yoke bracket 11, that is, below the shaft support portion 1a and the support 11b. A stator base 33 made of a wiring board or a glass cloth epoxy board is additionally provided.
Further, the power supply terminal portion 33a formed by projecting a part of the stator base 33 is held above the power supply terminal placement portion 1d by utilizing a step between the holding portion 1c and the shaft support portion 1a. The stator base 33 has three-phase armature coils, that is, three wound air-core armature coils 5A, 5B, and 5C, and six printed wirings connected in series to these air-core armature coils in a plan view. The air-core armature coils 5a, 5b and 5f are formed equally.
[0013]
The wound-type air-core armature coils 5A, 5B, and 5C are arranged within an opening angle of 180 degrees on one side, and three of the six printed-wire-type air-core armature coils 5a, 5b, and 5c are arranged at the same position. ing.
Here, instead of the printed wiring coil, it may be formed by attaching an insulated copper wire having a diameter of 0.05 mm in a single layer to a thin sheet having a thickness of about 0.05 mm coated with an adhesive, for example. .
On the stator base 33, on the opposite side through the centers of these wound air-core armature coils 5A, 5B, and 5C, the remaining three printed wiring air-core armature coils are provided so as to be between the trunks 11b. At the positions of 5d, 5e and 5f, a drive circuit member D1 formed as a sensorless IC and its attached parts are arranged. That is, the stator base 33 is located below the shaft support 1a and the support 11b of the yoke bracket 11, and the shaft support 1a and the support 1b are connected to the wound air-core armature coils 5A, 5B, 5C and the drive circuit member D1. It is provided within the thickness at a position excluding the attached parts and the like.
Naturally, the connection patterns of these drive circuit members are required, so the printed wiring air-core armature coils 5a, 5b, 5c on the drive circuit member arrangement side are formed only on the back surface, and the front surface is connected to the drive circuit members. Avoid winding patterns and start winding.
[0014]
These are integrated with a heat-resistant resin 4 such as liquid crystal or polyphenylene sulfide, which can withstand reflow soldering, so that the support 11b of the yoke bracket 11 becomes a skeleton.
Accordingly, the stator members such as the wound air-core armature coils, the drive circuit members, and the trunks arranged on the stator base 33 are not superimposed in plan view except for the printed wiring, so that the thickness can be reduced. Further, by integrally molding the support 11b with resin, the strength of the stator portion centering on the stator base 3 can be increased.
Although not specifically shown, the heat-resistant resin 4 may start up the air-core armature coil mounting guide instead of integral molding, and mount the air-core armature coil on this guide.
Thereafter, a flat cup-shaped cover member 100 made of stainless steel, which is thin nonmagnetic or weaker than iron, is covered, and the end of the shaft is inserted through a thrust washer S2 into a shaft mounting hole 10a formed in the center of the cover member 100. Fit. Here, the tip of the shaft mounting hole 10a is further narrower than the shaft diameter so that the tip of the shaft 2 does not protrude, and this tip is laser welded to the cover member 100 to prevent deformation. Is done. Although not particularly shown, this shaft mounting hole may be of a through-shaft type in the case of welding.
[0015]
The opening of the cover member 100 is assembled to the ring-shaped holding portion 1c of the yoke bracket 11 by laser spot welding. Therefore, the vibration motor assembled by welding as described above can obtain sufficient strength even when a thin member is used.
As a driving principle of such a sensorless type flat motor, a method of driving by detecting the direction of the back electromotive force of the air-core armature coil itself is adopted, but the description is omitted because it is publicly known.
Here, since the eccentric rotor R3 is the same as that described above, the same reference numerals are given and the description is omitted.
[0016]
Next, with reference to FIG. 12, a configuration of a shaft rotation type according to a third embodiment will be described.
Here, the same members or substantially the same members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.
That is, at the center of the yoke bracket 111, a shaft support portion 11a having a slightly larger diameter than that of the first embodiment is projected upward in a burring shape, and a sintered oil-impregnated bearing 77 attached to a thin yoke plate 66 here. Is stored. The other parts of the yoke bracket 111 are the same as those in the above embodiments, and the description thereof will be omitted.
Further, the eccentric rotor R4 is the same as described above except that the tip end side of the shaft is welded to the metal member 8a, and thus the same reference numerals are used and the description is omitted.
[0017]
Here, instead of the ball bearing B, the shaft may have a rounded base end. Since the eccentric rotor R4 is sucked toward the yoke bracket, a thrust washer is not required. Naturally, the cover member 101 may be of a blind type here.
[0018]
It should be noted that the above embodiments merely disclose the best embodying the technical idea of the present invention. Embodiments can be taken. Therefore, the above-described embodiments are merely examples and should not be construed as limiting. The technical scope of the present invention is defined by the appended claims, and is not limited by the description.
[0019]
【The invention's effect】
The present invention makes it possible to perform welding even when using a resin magnet containing a rare earth powder whose magnetic force can be easily controlled as described above, even when not using welding, even when not using welding. The impact resistance is maintained by devising the shape, and the axial gap type magnet can be firmly supported by a metal member at the inner diameter, so the impact resistance can be improved even with a small shaft support, thin and easy With a simple configuration, it is possible to obtain sufficient strength while making each member thin, and to incorporate drive circuit components, and to handle it in the same way as a normal DC motor. A vibration motor can be provided.
[Brief description of the drawings]
FIG. 1 is a plan view showing a first embodiment of an eccentric rotor of the present invention.
FIG. 2 is a vertical sectional view taken along the line AA of FIG.
FIG. 3 is a plan view of a modified example of FIG.
FIG. 4 is a longitudinal sectional view showing a second embodiment of the eccentric rotor of the present invention.
FIG. 5 is a cross-sectional plan view of the axially-gap type 1-hole sensor type coreless slotless brushless motor in which the eccentric rotor of FIG.
FIG. 6 is a sectional view of a modification of FIG.
FIG. 7 is a plan view of the stator shown in FIG. 5;
FIG. 8 is a plan view of one member of FIG. 7;
FIG. 9 is a cross-sectional plan view of a coreless slotless brushless vibration motor of a fixed shaft type and an axial gap type sensorless type equipped with an eccentric rotor of the present invention.
FIG. 10 is a longitudinal sectional view of FIG. 9;
FIG. 11 is a plan view of one member of FIG. 10;
FIG. 12 is a longitudinal sectional view of a shaft-rotating type axial gap type brushless vibration motor housing the eccentric rotor of the present invention.
[Explanation of symbols]
1, 11, 111 Bracket 2 Shaft 3 Stator base 4 Heat resistant resin 5A, 5B Air core armature coil 6, 66 Thin yoke plate R, R1, R2, R3, R4 Eccentric rotor H Hall sensor D, D1 Drive circuit member 7, 77 Sintered oil-impregnated bearing 8, 88 Axial gap type magnet 9 Arc-shaped eccentric weight 10, 100, 101 Cover member

Claims (15)

An axial gap type magnet (8, 88) having a plurality of magnetic poles, a thin yoke plate (6, 66) for receiving the magnetic field of the magnet, and a specific gravity of at least 17 disposed at least partially outside the magnet The thin yoke plate is provided with a tongue piece (6c) on a part of the outer periphery thereof, and the eccentric weight is provided with a recess (9a) engaging with the tongue piece. ) Is provided, and is fixed to the outer periphery of the thin yoke plate by using the recess and the tongue piece, and is supported by a metal member (6b, 8a) provided on the inner diameter side of the axial gap magnet. Eccentric rotor. The thin yoke plate has a thickness of 0.2 mm or less, a flat portion (6h) receiving the magnetic field of the magnet, an outer diameter side hanging portion (6a) for fixing an eccentric weight, and an inner diameter side hanging portion (6) for supporting a shaft. 6b), a part of the tongue piece is projected horizontally outward from the outer diameter side hanging part, and a flange (6d) is projected horizontally inward from the inner diameter side hanging part. 2. The recess according to claim 1, wherein the recess is formed slightly deeper than the thickness of the tongue, and the tongue is fitted into the recess, an eccentric weight is distributed, and the metal member is supported by the inner flange. Eccentric rotor. 3. The eccentric rotor according to claim 2, wherein said shaft supporting means is engaged with a bearing (7, 77) by caulking (6e) or press fitting (6f). 2. The eccentric rotor according to claim 1, wherein said shaft supporting means is adapted to engage a part of said inner diameter side hanging portion with said shaft (2) by welding (L2). 2. The eccentric rotor according to claim 1, wherein another metal member (8a) is fixed to at least the thin yoke plate on the inner diameter side of the axial gap magnet, and is axially supported via the metal member. 2. The eccentric rotor according to claim 1, wherein said shaft supporting means is formed by engaging a portion of said inner diameter side hanging portion with said shaft by welding (Y) or press fitting. 2. An eccentric rotor according to claim 1, wherein said eccentric weight is brazed in a recess (9a) to a tongue (6c) of a thin yoke plate. The tongue piece (6c) and the recess (9a) of the eccentric weight cooperate with each other to control a radial movement, and the eccentric weight is fixed by bonding and the axial gap type. 2. The eccentric rotor according to claim 1, wherein a magnet is bonded to the thin yoke plate using each hanging part. A notch (6g) is provided at at least two places on the outer diameter side hanging portion of the thin yoke plate so as to substantially oppose as a locking portion, and a projection (9b) formed on the eccentric weight has a notch in the notch. The eccentric rotor according to claim 1, wherein the eccentric weight is adapted to be inserted into the eccentric weight, and the eccentric weight is fixed to the outer diameter side hanging portion using the recess (9a) and the projection. The eccentric rotor (R, R1, R2, R3 and R4) according to any one of claims 1 to 9, a yoke bracket (1) for rotatably supporting the eccentric rotor via a shaft, and the yoke bracket. Are centered on shaft bearings (1a, 11a), a stator base (3) arranged around the shaft bearings, and a plurality of air-core armature coils (5A, 5B, 55A) arranged on the stator base. , 55B and 55c). There is a support part (1b) extending in the radial direction integrally with the shaft support part, and a support part (1c) integral with the support part via a space (1e). The stator base (3) is made of a flexible substrate, 11. A part (D, D1) of a drive circuit member is arranged on the stator base in a space portion where the plurality of air-core armature coils are not arranged so as to be within the thickness of the air-core armature coil. The axial gap type brushless motor according to the above. A part of the drive circuit member is disposed in the space (1e) in a plan view, and at least a part of the stator base at a position where the part of the drive circuit member is disposed is within a thickness of the bracket (1). The brushless motor in the axial direction according to claim 11, wherein the brushless motor is adapted to fit therein. The yoke bracket has a thickness of 0.2 mm or less, a base end of the shaft (2) is fixed at the center, a resin (4) is integrated at least in the space (1e), and the eccentric rotor has a bearing (7). The brushless motor according to claim 11, wherein the shaft (2) is rotatably mounted on the shaft (2), and a tip of the shaft is fitted in a center recess (10a) of the cover member (10). The yoke bracket has a thickness of 0.2 mm or less, and a bearing (77) is provided on a central shaft support portion (11a), and a resin is integrated at least in a part of the space (1e). The axial gap type brushless motor according to claim 11, wherein a tip end side is supported by an inner diameter side of the thin yoke plate, and a base end of the shaft is pivotally supported on a bottom portion of the shaft support portion. The stator base (33) is disposed under the yoke bracket, and the drive circuit member is stored in a space (1e) formed by the support portion (1b) and the holding portion (1c), and includes the air-core armature coil. The brushless motor in the axial direction according to any one of claims 11 to 14, wherein the brushless motor is formed integrally with a resin (4).

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