JP3938397B2 - Axial gap type brushless motor having the same stator - Google Patents

Description

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

As a flat axial gap type brushless vibration motor, the present applicant has previously proposed a coreless slotless type motor that does not incorporate a drive circuit member. (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 product has a large size in the lateral direction, and the set is not mounted on the printed wiring board with the SMD method, and the cored type has a large thickness. There is no.
Therefore, the applicant of the present invention previously includes a cored, slotless coreless type, a part of a plurality of armature coils is deleted, a space is provided, and a drive circuit member is disposed in this space. is suggesting. (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 order to drive with 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 has a thickness conventionally, if it is arranged on the bracket, the arrangement space is not easily obtained, which causes a problem of reversing the motor itself with respect to thinning.
In view of this, the present invention enables a built-in drive circuit component so that it can be handled in the same way as a normal DC motor, and a detent torque generating member can be easily formed as thin as possible. An axial gap type brushless motor provided with the stator is provided.

In order to solve the above-mentioned problems , the present invention provides a stainless steel bracket made of non-magnetic or weak magnet , wherein the first end of the shaft (2) is fixed to the central shaft support portion (1a) as shown in claim 1. (1), a stator base (3) made of a printed wiring board attached to the bracket, and at least two air-core armature coils (single-phase connected to the stator base with an adhesive (4)) ( 5A, 5B), a drive circuit member (D) disposed on the stator base so as not to overlap with the air-core armature coil, and a recess (1d) formed by press working on the bracket, A stator provided with a detent torque generating portion (1e) printed with a coating made of magnetic powder in a recess;
A rotor rotatably mounted on the stator via an axial gap;
The rotor includes a rotor yoke (6), an axial gap type magnet (7) fixed to a flat portion of the rotor yoke and having a plurality of magnetic poles, and a bearing (8) disposed on the rotor yoke on the inner diameter side of the magnet. ) And an eccentric weight (9) disposed on the rotor yoke outside the magnet,
The rotor yoke has a tongue piece (6d) protruding in the horizontal direction outwardly following the flat portion, and the eccentric weight is fixed to the tongue piece,
The rotor is attached to the shaft via the bearing, covered with a cover member (10), and assembled to the stator at an opening of the cover member;
A shaft fixed type axial gap type brushless vibration motor is characterized in that the second end of the shaft is fitted into the cover member.
Specifically, as shown in claim 2, the detent torque generating portion is preferably formed so as to be color-identifiable from the bracket .

In the invention of claim 1, since the detent torque generating portion is extremely thin and is included in the bracket due to the recess, a thin one with negligible thickness is obtained, and the tongue piece is used as a means for fixing the eccentric weight, and the shaft Since the first end portion is fixed to the bracket and the second end portion is fitted into the cover member, sufficient strength can be secured.
In the invention of claim 2, since the detent torque generating portion can be distinguished from the bracket in color , the detent torque portion can be identified in appearance.

  A non-magnetic or weak-magnetic bracket having a shaft support portion arranged in the center, a stator base made of a printed wiring board attached to the bracket outside the shaft support portion, and a shaft support portion on the stator base. There are a single-phase air-core armature coil disposed opposite to the center, a drive circuit member for applying electric power to the air-core armature coil, and a detent torque generating member made of magnetic powder formed by printing.

FIG. 1 is a plan view of main members constituting the stator of the present invention, and FIG. 2 is a plan view of a stator including the members.
The bracket 1 is made of a non-magnetic or weak magnetic stainless steel plate with a thickness of 0.1 mm , and a shaft support portion 1a is raised in the center in the form of a burring at the center as shown in FIG. A cylindrical reinforcing member 1b made of free-cutting brass is press-fitted into the outer periphery of the steel plate.
On the outside of the cylindrical reinforcing member 1b in the radial direction, three detent torque generating grooves 1c having a depth of about 0.02 mm are formed by pressing together with the central recess 1d.
In the recess 1d and the three grooves 1c for the detent torque generating portion, a paint in which magnetic powder is dissolved is printed and formed as a detent torque generating portion 1e by transfer or the like. This paint is colored so that it can be easily distinguished from the bracket 1.
In this way, the detent torque formation status can be judged at a glance from the outside, and the detent torque generating portion 1e is embedded in the recess, so that the thickness is thin, and within the thickness of the bracket, the thickness of the stator is sacrificed. Don't be.
The bracket 1 further includes a power supply terminal mounting portion 1f with a part of the outer diameter protruding in the radial direction.
A small shaft 2 of 0.5 mm to 0.6 mm is press-fitted into the shaft support portion 1a of the bracket 1 at the base end which is the first end portion, and a stator base 3 made of a flexible printed wiring board is disposed around the shaft 2. It is placed and a part of it is superposed on the feeding terminal placement portion 1f as the feeding terminal portion 3a.
Two air-core armature coils 5A and 5B are placed on the stator base 3 so as to face each other, and are connected in series so as to have a single phase.
These air-core armature coils 5A, the space between 5B, and one Hall sensor H, I C of been driven circuit member D are disposed to face each. Here, in order to obtain a magnetic bias, the Hall sensor H is at least partially applied to the detent torque generating unit 1e.
Here, the positional relationship between the detent torque generator and the single-phase air-core armature coil is set so that the effective conductor of the air-core armature coil matches the magnetic pole of the magnet described later, and the shape of the detent torque generator is the magnetic force of the magnet. It is preferable to set so that the minimum stalling torque can be obtained when the motor is stopped.
The stator thus configured is fixed to the stator base 3 with the ultraviolet curable adhesive 4 from the periphery of the reinforcing member 1b to the two air-core armature coils 5A and 5B, the Hall sensor H, and the drive circuit member D. Here, at least a part of the air-core armature coil is required to be reinforced by the ultraviolet curable adhesive 4 and, of course, the space between the opposed rotor and the member that determines the minimum air-gap (here, the air-core armature coil) is used. The injection volume is controlled so that it does not stick out. Here, the periphery of the reinforcing member 1b is preferably welded to the yoke plate by laser welding. Therefore, these stator members do not overlap in plan view, can be configured to be thin, and the impact resistance is improved by the ultraviolet curable adhesive.

3 is a longitudinal sectional view of a shaft-fixed axial gap type coreless slotless brushless vibration motor including the stator of FIG.
The eccentric rotor R that is rotatably mounted on the shaft 2 includes a thin rotor yoke 6 made of magnetic stainless steel, an axial gap type magnet 7 disposed on the thin rotor yoke 6, and a collar disposed on the inner diameter portion of the magnet 7. The rotor yoke 6 is formed with a thin thickness of 0.1 mm , and receives a magnetic field of the magnet 7; and a flat portion 6a that receives the magnetic field of the magnet 7. There are an outer-diameter side hanging portion 6b for fixing the arc-shaped eccentric weight 9 and an inner-diameter side hanging portion 6c that supports the shaft, and a tongue piece 6d integrally protrudes outward in the horizontal direction from the outer-diameter side hanging portion 6b. A flange 6e protrudes inward from the inner diameter side hanging portion 6c in the horizontal direction, the eccentric weight 9 is disposed on the tongue piece 6d, and the flanged sintered oil-impregnated bearing 8 is connected to the inner diameter side flange 6e. It is attached by staking or spot welding. In this way, the eccentric weight 9 is configured by fixing the tongue piece 6c by brazing or bonding, and the magnet 7 is mounted by spot welding or the like in the case of a bonded or rare earth sintered metal magnet.
The eccentric rotor R is rotatably mounted on the shaft 2 via at least two thrust washers S1 stacked to reduce brake loss. Thereafter, a cover member 10 made of a thin non-magnetic stainless material is covered, and the second end, which is the tip of the shaft, is fitted into a burring hole 10a formed at the center of the cover member 10 via a thrust washer S2. Here, the burring hole is thinner than the shaft diameter so that the second end portion of the shaft 2 does not protrude, and this tip portion is laser welded to the cover member 10 to prevent deformation. At the same time, the opening of the cover member 10 is assembled on the outer periphery of the bracket 1 by laser spot welding.
The second end of the shaft 2 is first fixed to the cover member 10 by laser welding, the eccentric rotor R is mounted from the first end side, and the first end is press-fitted into the shaft support portion on the stator side. The first end portion may be laser welded to the shaft support portion from the outside.
Therefore, since it is assembled by welding in this way, a monocoque structure is formed as a whole, so that sufficient strength can be obtained even if a thin member is used.

FIG. 4 is a bottom view of another main member constituting the stator of the present invention.
In this embodiment, the detent torque generating portion is formed on the stator base 33, and the same members or substantially the same members having the same functions as those of the above-described embodiments are denoted by the same reference numerals and the description thereof is omitted.
That is, three detent torque generating portion lands 33c are formed by printing on the back surface of the stator base 33 made of a flexible printed wiring board, and pure iron plating is applied thereto as the detent torque generating portion.
Even if it comprises in this way, since the thickness can be disregarded as a detent torque generation part, it can be made very thin as a stator.
In the figure, 33a is a through hole for mounting on the shaft support portion 1a of the bracket 1, and 33b is a guide hole for mounting the air core armature coils 5A, 5B on the front side. The broken line similarly shows the Hall sensor H and the drive circuit member D arranged on the stator base on the front side.

The present invention, in the bracket 1 as detent torque generating unit embodiment the preceding example showed that formed by printing the magnetic powder coating, also made by forming a magnetic plating such as pure iron and a predetermined masking It is also possible to transfer the magnetic powder paint on the stator base.
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 main member which comprises the stator of this invention. It is a top view of the stator containing the same member of FIG. Example 1 FIG. 3 is a longitudinal sectional view of a shaft-fixed axial gap type coreless slotless brushless vibration motor including the stator of FIG. 2. (Example 2) It is a bottom view of another form of the main member which comprises the stator of this invention. (Example 3)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bracket 1e, 33e Detent torque generating part 2 Axes 3, 33 Stator base 4 UV curable adhesive 5A, 5B Air core armature coil 6, 66 Rotor yoke R Eccentric rotor H Hall sensor D Drive circuit member 7 Axial direction gap type magnet 8 Sintered oil-impregnated bearing with flange 9 Arc-shaped eccentric weight 10 Cover member

Claims (2)

It consists of a stainless steel bracket (1) made of a non-magnetic or weak magnetic material with the first end of the shaft (2) fixed to the central shaft support (1a), and a printed wiring board attached to the bracket. A stator base (3), at least two air-core armature coils (5A, 5B) at least partially fixed to the stator base with an adhesive (4) and single-phase connected, and the air-core armature coil superimposed. The drive circuit member (D) disposed on the stator base and the recess (1d) formed by press working on the bracket are formed, and the recess is printed with a coating made of magnetic powder. A stator provided with a detent torque generator (1e) ,
A rotor rotatably mounted on the stator via an axial gap;
The rotor includes a rotor yoke (6), an axial gap type magnet (7) fixed to a flat portion of the rotor yoke and having a plurality of magnetic poles, and a bearing (8) disposed on the rotor yoke on the inner diameter side of the magnet. ) And an eccentric weight (9) disposed on the rotor yoke outside the magnet,
The rotor yoke has a tongue piece (6d) protruding in the horizontal direction outwardly following the flat portion, and the eccentric weight is fixed to the tongue piece,
The rotor is attached to the shaft via the bearing, covered with a cover member (10), and assembled to the stator at an opening of the cover member;
A shaft-fixed axial gap type brushless vibration motor, wherein a second end portion of the shaft is fitted into the cover member. The detent torque generating section shaft fixed axial gap type brushless vibration motor of claim 1 which is formed so as to be distinguished from the bracket and color.

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