JP4402671B2 - Stator and axial gap type brushless vibration motor having the same stator - Google Patents

Description

  The present invention relates to a stator and an axial gap type brushless vibration motor that is suitable for use in a silent notification means of a mobile communication device and is provided with the stator.

As a flat axial gap type brushless vibration motor, a coreless slotless type motor composed of one bearing has been proposed. (See Patent Document 1 and Patent Document 2)
As a brushless vibration motor with a drive circuit, it is a cored type, a cored type in which armature coils are wound around a plurality of equally arranged salient poles, and a non-circular drive circuit member is arranged on the side of the stator. Things are known. (See Patent Document 3)
However, such a device has a large size in the lateral direction, and the mounting efficiency is poor with the SMD method on the printed wiring board of the set, and because of the cored type, the thickness must be large and practical. There is no.
Further, there has been proposed a structure including a cored and slotless coreless type in which a part of a plurality of armature coils is deleted to provide a space, and a drive circuit member is disposed in this space. (See Patent Document 4)
Japanese Utility Model Publication No. 4-137463 JP 2002-143767 A JP 2000-245103 A JP 2002-142427 A (FIGS. 8 to 11)

By the way, in the single-phase type driven by one Hall sensor, a detent torque generating member that stops the position of the magnet of the rotor at a specific place that can be reliably started next time is required.
Since this detent torque generating member requires a certain amount of thickness in order to obtain the required detent torque generating force, it is difficult to arrange the detent torque generating member on the bracket, and this is a reverse to the thinning of the motor itself. Will become a problem.
In addition, when the detent torque generating member is formed by, for example, printing, a certain degree of thickness and width are still necessary to obtain a necessary detent generating force, and the thickness is substantially sacrificed. There is no change.
In addition, some brackets with a stator base are formed with a magnetic portion and a nonmagnetic portion, but the detent generation function is weakened by the amount corresponding to the stator base.
For this reason, in order to generate a large detent torque, a detent torque part is raised from the bracket and stored in the inner diameter part of the air-core armature coil so that the thickness of the detent torque generating member can be substantially ignored. Has been.
However, there is a problem that the number of turns of the air-core armature coil cannot be increased. In other words, the arrangement position of the detent part needs to be deliberately shifted from the center of the coil so that it may stop at either the center of the magnetic pole or the neutral position in order to avoid a starting error, but the inner diameter of the coil is small. And this shift angle cannot be increased. If the predetermined shift angle cannot be maintained, the position of the effective conductor that contributes to the torque is sacrificed and the starting torque is reduced.
Therefore, the present invention makes it possible to completely ignore the arrangement thickness of the detent torque generating member and to set a predetermined optimum detent torque generating member position (shift angle) regardless of the inner diameter of the coil. An axial gap type brushless vibration motor provided with the same stator is provided.

In order to solve the above-mentioned problems, a magnetic bracket having a shaft support portion arranged at the center, a stator base made of a printed wiring board attached to the bracket, and a stator base arranged as described in claim 1 are provided. A stator including a plurality of air-core armature coils formed and a drive circuit member disposed on the stator base so as not to overlap with the air-core armature coil, and a rotor combined with the stator via an axial gap The rotor is provided with an axial gap type magnet having a plurality of magnetic poles arranged on the rotor case and an eccentric weight, and an outer case is attached to the stator so as to cover the rotor. A brushless vibration motor,
The stator base has a central through hole disposed in the shaft support portion and at least one through hole formed radially outward of the central through hole,
The through hole is provided at a position where the arrangement opening angle is approximately 1/4 of the opening angle of the magnetic pole of the axial gap magnet from the center of the air-core armature coil,
Wherein the through hole can be achieved with what the detent torque portion formed raised against the integrally of a magnetic material bracket is stored to fit to the stator base in the thickness.
Specifically, as shown in claim 2, it is preferable that magnetic attraction force relaxation means be formed adjacent to the detent torque portion of the magnetic bracket .

In the first aspect of the present invention, since the detent torque portion is included in the stator base, the thickness is substantially negligible, and the detent torque portion is set at a position irrelevant to the inner diameter of the air-core armature coil. Since each member constituting the stator does not overlap, a thin vibration motor that can be formed extremely thin and has sufficient shock resistance can be obtained.
In the invention shown in claim 2, even if the detent torque portion is thin, a sufficient detent torque can be secured by the adjacent magnetic attraction force relaxation means .

  A magnetic bracket having a shaft support portion disposed at the center, a stator base made of a printed wiring board attached to the bracket, a plurality of air core armature coils disposed on the stator base, and the air core armature coil And a drive circuit member disposed on the stator base so as not to overlap with the stator base. The stator base is further provided with a central through hole disposed in the shaft support portion and radially outward of the central through hole. At least one through hole, and the detent torque part formed integrally protruding from the magnetic bracket is stored in the through hole so as to be within the thickness of the stator base. FIG. 2 is a plan view of a stator base which is a main member constituting the stator of the present invention, FIG. 2 is a plan view of a bracket attached to the stator base, and FIG. Assembled view of the stator with and Figure 4, is a vertical sectional view in the axial direction gap type brushless vibration motor having such a stator.

1 to 3, the bracket 1 constituting the stator ST of the present invention is formed of a magnetic stainless steel plate (for example, SUS430 series) with a thickness of about 0.2 mm, and a shaft support portion 1a is formed by pressing at the center. Then, four elongate protrusions 1b as a detent torque portion are protruded from the back surface by pressing at a pitch of 60 ° outward in the radial direction. The height of the projection 1b is set within the thickness of a stator base described later, and is characterized in that it functions to generate detent torque. The bracket 1 is further provided with a rectangular through hole 1c at a position where a drive circuit member, which will be described later, is disposed, and a feeding terminal mounting portion 1d extending laterally.
Here, in order to make the detent torque generating function more effective, it is desirable to leave a magnetic attraction force relaxation means 1e composed of a plurality of small holes or dents adjacent to the protrusion 1b.

The stator base 2 attached to the bracket 1 is made of a flexible substrate having a thickness of about 0.1 mm, and the central through holes 2a to be attached to the shaft support portion 1a and the protrusions formed at a 60 ° pitch on the outer side. Four long holes 2b are opened at positions corresponding to 1b.
Further, four air-core armature coil mounting guide holes 2c formed at a pitch of 60 ° are formed outside the central through-hole 2a, and the winding start terminal lead-out escape groove 2i of the air-core armature coil is formed in each of the electric machines. It is connected to the guide hole 2c for mounting the child coil. In order to cover insufficient strength due to these holes, a discarded pattern 2d, a coil connection pattern 2e, and a drive circuit connection pattern 2f are formed at required positions.
Here, the position of the long hole 2b is provided at a position where the opening angle is about 15 ° from the center of each armature coil mounting guide hole 2c, which is the center of the air-core armature coil to be disposed.
In addition, a power supply terminal portion 2g is extended laterally at the position of the power supply terminal mounting portion 1d.
Naturally, each pattern is subjected to resist processing except for each connection portion indicated by hatching, and a notch 2h is formed next to the drive circuit connection pattern 2f so that it can be easily bent.

When the opening angle of the magnetic pole of the axial gap magnet of the rotor to be combined is 60 °, the arrangement opening angle of 15 ° is a position where the magnet may stop at either the peak of the magnetic pole or neutral. .
Of course, when the opening angle of the magnetic poles of the axial gap magnet of the rotor is 90 °, it is desirable to set it to 22.5 °.

As shown in the assembly diagram of FIG. 3, the stator base 2 has four air-core armature coils 3 that are wound with a winding shaft that is substantially the same size as the air-core armature coil mounting guide hole 2 c. The end of the coil mounting guide hole 2c is fixed with a UV curable anaerobic adhesive using a jig or the like, and the terminal is soldered to the predetermined coil connection pattern 2e so as to be a single phase.
Since it is connected to this single phase, it may be constituted by two air-core armature coils if the thickness is allowed.
In FIG. 3, the air-core armature coil terminal, each connection pattern, and the like are omitted to prevent complication.
Here, each of the armature coil mounting guide holes 2c has a process of attaching the coil to the jig and applying an adhesive, and then covering the stator base 2 to attach the air core armature coils 3. If adopted, it is not necessarily provided.

The hall sensor built-in type drive circuit member D for driving the air-core armature coil 3 is soldered to a position where an appropriate electrical neutral point is obtained so as not to overlap the air-core armature coil 3 in plan view. Here, the position of the built-in Hall sensor is determined according to the magnetic poles of the magnets to be combined. Here, in the case of a magnet having six magnetic poles, 90 °, 150 °, 210 ° and 270 ° from the center of the air-core armature coil. Chosen to be placed in either.
The stator base 2 thus configured is attached to the bracket 1 via an anaerobic adhesive. At this time, the detent torque generating projection 1b is mounted in the elongated hole 2b. Therefore, it completely fits in the thickness direction of the stator base 2, and as a result, it is not necessary to consider the thickness at all. That is, as described above, the optimum position can be set without being forced to fit within the inner diameter of the air-core armature coil.
Here, since there is a through hole 1c at the position where the drive circuit member D is arranged, the stator base 2 is partially dropped at this position, and the height of the drive circuit member D can be placed low. Become.
In this embodiment, each of the four long holes 2b and the detent torque generating projection 1b is provided. However, for example, when the thickness of the stator base is 0.15 mm or more, the height of the detent torque generating projection 1b is also 0. Since it can be formed to be 15 mm or more and the detent torque generating function can be further enhanced, even one of them can be used. On the other hand, in order to suppress the thickness of the motor to 2 mm or less, the thickness of the stator base needs to be about 0.1 mm as in the present embodiment. In such a case, the long hole 2b and the detent torque generating projection are required. It is preferable to provide two or more 1b.

FIG. 4 shows a shaft rotation type axial gap type coreless slotless brushless vibration motor provided with the stator ST described above.
The eccentric rotor R opposed to the stator via an axial gap is arranged on an axial gap type magnet 4 having a surface that is easily soldered, such as nickel plating, and a part of the outer periphery of the magnet 4. The arc-shaped eccentric weight 5, the rotor case 6 having a thickness of about 0.15 mm for fixing them, and the shaft 7 fixed to the rotation center of the rotor case 6 constitute a housing. It is stored in the outer case 8 and assembled by laser welding Y on the outer periphery of the bracket 1 at the opening.

  The rotor case 6 is formed with a bearing support portion 6a and a flat portion 6b to which the upper portion of the magnet 4 connected thereto is bonded. The flat portion 6b is formed to be slightly smaller than the outer diameter of the magnet 4.

The eccentric weight 5 has a main portion 5a formed in an arc shape and a ceiling portion 5b formed integrally with the main portion 5a, and a gap through which the magnet can be seen is formed between the flat portion 6b. Yes. The eccentric weight 5 is fixed by soldering with a flat portion, a part of the magnet 4 and a ceiling portion 5b with lead-free solder HD in the gap portion.
Similarly, the magnet 4 and the rotor case 6 are fixed to each other on the opposite side of the eccentric weight 5 by soldering.
Needless to say, these solders can be reflowed and the magnet is magnetized after soldering.
Therefore, since these members are fixed by soldering, impact resistance can be ensured.

The eccentric rotor R configured as described above is rotatably mounted on the shaft 7 via the three thrust washers SW whose diameters are mutually changed via the oil-impregnated bearing 9 mounted on the bearing support 6a. Covered and assembled.
Here, the tip of the shaft 7 is further laser-welded L so as to withstand a radial impact.
The opening of the outer case 8 covering the eccentric rotor is assembled by laser spot welding on the outer periphery of the bracket 1 on the stator side.

The stator according to the present invention is not limited to a vibration motor, but can be applied to a normal rotation type single-phase brushless motor such as a general fan motor. In addition, the shaft support part may be a brass bearing holder type instead of the support part integrally raised on the bracket. If the bearing is fixed to these shaft support parts and the shaft is fixed to the rotor side, the shaft rotation type You can also.
The present invention can take various other embodiments without departing from the technical idea and characteristics thereof. Therefore, the above-described embodiment is merely an example and should not be interpreted in a limited manner. The technical scope of the present invention is indicated by the claims, and is not restricted by the text of the specification.

It is a top view of the stator base which is a main member which comprises the stator of this invention. It is a top view of the bracket with which the stator base of FIG. 1 is mounted. FIG. 3 is an assembly diagram of a stator ST including the stator base of FIG. 1 and the bracket of FIG. 2. Example 1 FIG. 4 is a longitudinal sectional view of an axial gap type brushless vibration motor including the stator of FIG. 3. (Example 2)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bracket 1a Shaft support part 1b Protrusion 1c Through-hole 1d Feeding terminal mounting part 1e Magnetic adsorption force relaxation means 2 Stator base 2a Central through-hole 2b Long hole 2c Air-core armature coil mounting guide hole 2d Discard pattern 2e Coil connection pattern 2f Drive circuit connection pattern 2g Feed terminal portion 2h Cut 3 Air core armature coil 4 Axial gap magnet 5 Eccentric weight 5a Main portion 5b Ceiling portion 6 Rotor case 6a Bearing support portion 6b Flat portion 7 Shaft 8 External case 9 Oil-impregnated bearing R Eccentric Rotor D Drive circuit member ST Stator

Claims (2)

A magnetic bracket having a shaft support portion disposed at the center, a stator base made of a printed wiring board attached to the bracket, a plurality of air core armature coils disposed on the stator base, and the air core armature coil And a stator provided with a drive circuit member disposed on the stator base so as not to overlap with
A rotor combined with an axial gap in the stator,
The rotor includes an axial gap type magnet having a plurality of magnetic poles arranged on a rotor case and an eccentric weight, and an axial gap type brushless vibration motor in which an outer case is assembled to the stator so as to cover the rotor. Because
The stator base has a central through hole disposed in the shaft support portion and at least one through hole formed radially outward of the central through hole,
The through hole is provided at a position where the arrangement opening angle is approximately 1/4 of the opening angle of the magnetic pole of the axial gap magnet from the center of the air-core armature coil,
Axial gap type brushless vibration motor, characterized in that the detent torque portion formed raised against the integrally from the magnetic body bracket is stored to fit to the stator base in the thickness in the through hole. 2. The axial gap type brushless vibration motor according to claim 1, wherein magnetic attraction force relaxation means is formed adjacent to a detent torque portion of the magnetic bracket .

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