JP3985964B2 - A stator having detent torque generating means and an axial air gap type brushless motor having the same stator - Google Patents

Description

  The present invention relates to a stator having detent torque generating means suitable as a silent notification source of a mobile small communication device and a vibration source of a massager, and an axial gap type brushless motor provided with the stator.

In recent years, in mobile communication devices, vibration motors having a function of utilizing vibration in addition to silent alarm means have started to appear. In such a case, with a conventional cylindrical or flat brush type, there is a sliding part, so the life becomes a relatively problem.
Conventionally, some brushless motors are provided with three hall sensors in three phases. However, when a fan motor is used, is it provided with a single-phase air-core armature stator with a simple configuration? (Refer to the above) One having a three-phase sensorless stator is known. By the way, from the convenience of handling as a brushless motor, it is desired that the power supply terminal has two positive and negative terminals, that is, a built-in drive circuit, as in a normal brush type motor (see Patent Documents 2 and 3).

In the case of a stator having a single-phase air-core armature coil that cannot normally be self-started, a magnetic material for generating a detent torque is used as a means for stopping the rotor at a required position so that self-start can be performed. Need to be placed in In addition, in the thin and small axial gap type brushless, special consideration is required for the arrangement of the detent torque generating member together with the built-in driving circuit member. Japanese Patent No. 3537815 has been proposed as an arrangement example of such a detent torque generating member. (See Patent Document 3)
JP 11-8951 A JP 2002-142427 Japanese Patent No. 3537815

However, when a recent small size such as a radial size of 10 mm or less is required, the area occupied by the wound air-core armature coil becomes large even if it is a single-phase type, and two windings are required. In the case where the linear air-core armature coil is arranged, it is difficult to store the drive circuit member.
Accordingly, an object of the present invention is to enable easy start-up even if the number of wire-wound air-core armature coils is reduced, and to reduce the thickness of the detent torque magnetic body while contributing to torque generation by using an armature coil type as a detent torque generating means. By making good use of a printed wiring type air-core armature coil with a small number of turns while being placed in the main magnetic field for miniaturization, an appropriate stopping torque can be obtained. Therefore, even if it is adopted for a single-phase armature coil type that cannot be self-started, it can be reliably started by stopping at a position where maximum torque can be obtained. To do.

In order to solve the above-mentioned problem, a stator for driving a rotor provided with an axial gap magnet as set forth in claim 1, wherein the stator base made of a printed wiring board has at least one wound-type air core armature. A coil is disposed and at least one printed wiring type air-core armature coil is formed, and a magnetic thin film is formed on at least a part of the printed wiring type air-core armature coil to combine with the rotor to form a detent. This can be achieved by generating torque.
Specifically, as shown in claim 2, the wound-type air-core armature coil is disposed on a first surface of the printed wiring board, and at least a part of the printed-wire-type air-core armature coil is a second surface. The magnetic thin film is formed by magnetic plating, and is formed on the first surface of the printed wiring board in a plan view. It is preferable that the drive circuit member is arranged so as not to overlap with the coil.
Then, to the axial direction gap type brushless motor uses these stator, a rotor which combine the stator according to claim 1 or 2 as shown in claim 3 is the thickness at 0.2mm below the rotor yoke And an axial gap magnet held by the rotor yoke, and an eccentric weight arranged on the rotor yoke outside the magnet, and is rotatably stored in the yoke bracket and the cover member via the shaft. This can be achieved.

According to the first aspect of the present invention, since the detent torque generating means arranged in a part of the printed wiring type air-core armature coil is formed of a magnetic thin film, the thickness can be almost ignored. In addition, the air gap in which the main magnetic field is generated is not sacrificed, and the stop torque is also moderate. Therefore, the loss of magnetic flux can be reduced, and the printed wiring type armature coil can contribute to the generation of torque.
According to the invention of claim 2, since only one winding type air-core armature coil is required, the configuration is simple and the assembly is facilitated, and the printed wiring type air-core coil can contribute to the generation of torque by increasing the quantity, and the drive circuit Can be easily mounted.
According to the third aspect of the present invention, it is possible to obtain an axial gap type vibration motor which is extremely thin, can be started up reliably, and is advantageous in cost.

One winding-type air-core armature coil is arranged on the first surface of the stator base made of the printed wiring board, and three printed-wiring type air-core armature coils are formed on the second surface. A drive circuit member is arranged so that a detent torque is generated in combination with the rotor by magnetically plating at least a part of the air-core armature coil and is not superimposed on the wound-type air-core armature coil.
FIG. 1 shows a stator according to the present invention, and is a plan view seen from the first surface side of the stator base. FIG. 2 is a plan view seen from the second surface side of the stator base of FIG. Example 1
FIG. 3 is a cross-sectional view of a flat brushless vibration motor including the stator of FIG.
FIG. 4 is a plan view seen from the second surface side of the stator base in which six printed wiring type air-core armature coils are formed in the modification of FIG. (Example 2)
FIG. 5 is an explanatory diagram of the connection relationship of FIG.

1 and 2, the yoke bracket 1 constituting the stator is a non-magnetic or weak magnetic stainless steel plate having a thin thickness of 0.1 mm to 0.2 mm, and has a shaft protruding in the center in a burring shape. There is a bearing 1a. A thin shaft 2 having a thickness of about 0.6 mm is erected on the shaft support portion 1a by press-fitting a base end thereof, and a stator base 3 made of a thin printed wiring board is placed around the shaft support portion 1a by adhesion or the like. . Here, when the shaft 2 is only press-fitted and the strength cannot be secured, it is preferable to perform laser welding Y on the base end from the outside (the back side of the paper in FIG. 1). On the stator base 3, one wound air-core armature coil 4 is placed on the first surface (upper surface). The second surface (lower surface) of FIG. 2 is formed with three printed wiring air-core armature coils 4a, 4b, and 4c with an opening angle of 120 °. The opening angle and number of coils are determined according to the number of poles of the rotor-side magnet to be combined. Here, the rotor-side magnet 8 to be combined is composed of six poles.
Each air core armature coil 4, 4 a, 4 b, 4 c is set so that the effective conductor portions at both ends are placed on the NS pole of the magnet 8 to be combined. A single-phase armature is configured by connecting to the winding type air-core armature coil 4 on the first surface side through a through hole or the like and also to the winding type air-core armature coil 4 in series. The surface of the printed wiring air-core armature coils 4a... Is partially subjected to magnetic plating such as pure iron of about 10 microns as the magnetic thin films M and M1.
The position of the magnetic plating is constituted by a combination of M at the position of the effective conductor portion and M1 at the position of the ineffective conductor portion that covers the neutral of the magnet to be combined. (Hereinafter, the magnetic thin film is referred to as magnetic plating.)
As a result, the effective conductor portion of each air-core armature coil is surely stopped at the maximum magnetic field of the magnet upon receiving the magnetic field of the axial gap type magnet 8 to be combined. The magnetic plating surface is resist-treated because it needs to be insulated when attached to the yoke bracket 1.
In addition, in order to connect each printed wiring type air-core armature coil in series as a set of single-phase air-core armature coils, a through hole in the inner diameter portion is necessary, but detailed description thereof is omitted here.

One hall sensor h and an integrated drive circuit member Dr that receives the output of the hall sensor h are arranged at a position that does not overlap with the wound type air-core armature coil 4 on the first surface side of the stator base 3. Then, it is fixed together with the air-core armature coil 4 with an ultraviolet curable resin 5. As shown in FIG. 3 to be described later, the resin 5 does not appear on the upper surface of the maximum mounting member that determines the gap, here, the drive circuit member Dr. Each of these members may be integrally molded with a general injection molding resin.
Here, the Hall sensor h and the drive circuit member Dr are arranged to face each other, but it is not necessary to limit the position of the Hall sensor h and the drive circuit member Dr. In such a stator S, a part of the outer periphery of the yoke bracket 1 protrudes sideways. The power supply terminal mounting portion 1b is formed to protect the power supply terminal 3a of substantially the same size protruding from a part of the outer periphery of the stator base 3 as well.
The Hall sensor h is preferably arranged at a position where the magnetic plating M of the printed wiring type air-core armature coil on the back side (second surface side) in a plan view is used for increasing the output. In this way, the output of the Hall sensor h can be sufficiently obtained, and the position of the magnetic plating as the detent torque generating portion, the position of the wound-type air core armature coil, and the formation position relationship of the printed wiring air core armature coil are as follows. The effective conductor portion of the child coil is set so as to be positioned in the magnetic field of the magnetic pole of the magnet 8 to be combined as shown by the imaginary line. When the magnetic plating M and M1 are stopped by the magnetic force of the magnet 8, their positions are set so that the minimum starting torque can be obtained in all positions. That is, almost the center of the magnetic pole, which is the maximum magnetic field, stops on the effective conductor portion of each air-core armature coil 4, 4a, 4b, 4c, so that a large starting torque can be obtained and the starting becomes easy. In this case, the detent torque generating member is made of the magnetic plating M partially formed on the printed wiring air-core armature coil, so that the thickness is almost neglected and can be made thin. When the detent torque due to the small thickness of the magnetic plating is small, the number of plating positions can be increased, and the magnetic thin film M1 can be formed on a plurality of invalid conductor portions so that the neutral portion of the magnet to be combined is straddled. good.

  FIG. 3 shows an axial gap type brushless motor using such a stator, in particular, a brushless vibration motor in which the rotor is eccentric in this case. That is, to the thin yoke plate 6 which is a member constituting the eccentric rotor R, the axial gap type magnet 8 obtained by firing rare earth magnet powder is bonded. The thin yoke plate 6 has a flat portion 6h that receives the magnetic field of the axial gap type magnet 8, an outer diameter side hanging portion 6a and an inner diameter side hanging portion 6b that are integral with the flat portion 6h, and the axial gap type. Since the magnet 8 is enclosed, the magnet 8 has a strong adhesive force. On the outer diameter side hanging portion 6a to which the arc-shaped eccentric weight 9 is fixed, two tongue pieces 6c are integrally projected to the outer diameter side hanging portion 6a horizontally and outward in the normal direction, and a flange 6d is provided. An eccentric weight 9 is disposed so as to be fitted in and received by a recess 9a that protrudes horizontally inward from the inner diameter side hanging portion 6b and matches the tongue piece 6c, and the inner diameter side drooping is performed on the inner diameter side of the magnet. A flanged sintered oil-impregnated bearing 7 is attached to the flange 6d integrally projecting inward from the portion 6b by caulking K.

In this way, the arcuate eccentric weight 9 can be easily configured as the eccentric rotor R by fixing the recess 9a and the tongue piece 6c by brazing or bonding. Here, in order to ensure strength, the eccentric rotor R is rotatably mounted on a shaft 2 whose base end is laser welded Y by being press-fitted into the central shaft support portion of the yoke bracket 1. In doing so, in order to reduce brake loss, it is rotatably mounted on the shaft 2 via a thrust washer S1 laminated in two to three sheets. Thereafter, a shallow cap-shaped cover member 10 made of a thin nonmagnetic stainless material is covered, and the tip of the shaft is fitted into a shaft mounting hole 10 a formed in the center of the cover member 10. 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 portion is provided with a laser on the cover member 10 to prevent deformation upon impact. In addition to spot welding Y, the opening edge of the cover member 10 is assembled to the outer peripheral portion 1 c of the yoke bracket 1 by laser spot welding L.
Accordingly, since the monocoque structure is assembled by welding including the end portion of the shaft in this way, sufficient strength can be obtained even if thin and thin members are used.

Thus, the stator S composed of the wound air-core armature coil 4, the hall sensor h, the drive circuit member Dr, and the like provided on the stator base 3 is housed in the cover member 10 constituting the housing together with the eccentric rotor R. Therefore, it is only necessary to lead out the pair of power supply terminals 3a from the power supply terminal mounting portion 1b to the outside of the motor, so that it can be handled in the same manner as a normal motor although it is a brushless motor.
If the cover member 10 is made of nonmagnetic austenitic stainless steel, it has a heat insulating effect and can withstand reflow.

  FIG. 4 shows the printed wiring type armature coil formed on the stator base that is formed of 6 pieces in order to ensure the number of turns in a single phase. Each printed wiring type armature coil 4d-4i is directly connected by changing the winding direction between the outer diameter portions through the through holes at the beginning of the inner diameter portion winding. As shown in the image of FIG. 5, the connection state is established. Also here, the magnetic plating M as the magnetic thin film is set so as to avoid the neutral position of the magnet 8 to be combined as shown by the imaginary line, and the magnetic plating M1 of the invalid conductor portion is set to be the neutral portion. . As a result, the effective conductor portions of the six printed wiring type armature coils 4 d to 4 i and the effective conductor portion of the winding-type air-core armature coil 4 on the first surface side are stopped in the maximum magnetic field of the magnet 8. If the direction of the current is given in the direction of the arrow, a magnetomotive force that drives the magnets in the same direction is generated in all the coils, and the activation becomes easy.

Although each of the above embodiments has exemplified a brushless vibration motor, the stator can also be used as a normal rotary brushless motor, for example, a fan motor having a fan attached to a rotor. Moreover, although what consists of magnetic plating was shown as a magnetic thin film, you may print the coating material which melt | dissolved magnetic powder. Furthermore, two or more wire-wound air-core armature coils may be used if size and cost are provided.
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 the top view seen from the 1st surface side of the stator base as a stator of this invention. It is the top view seen from the 2nd surface side of the stator base of FIG. Example 1 It is sectional drawing of the flat brushless vibration motor provided with the stator of FIG. 1, FIG. FIG. 6 is a plan view of a stator base as viewed from the second surface side in which six printed wiring type air-core armature coils are formed in the modification of FIG. 2. (Example 2) It is explanatory drawing of the connection relation of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Yoke bracket 2 axis | shaft 3 Stator base 4 Winding type | mold air-core armature coil 4a-4i Printed wiring type | formula air-core armature coil 5 Resin 6 Thin yoke plate 7 Bearing 8 Axial direction gap type magnet 9 Eccentric weight 10 Cover member M, M1 Magnetic thin film h Hall sensor Dr Drive circuit member

Claims (3)

  A stator for driving a rotor provided with an axial air gap type magnet, wherein a stator base made of a printed wiring board is provided with at least one winding type air core armature coil and at least one printed wiring type air core electric machine. And a detent torque generating means for generating detent torque in combination with the rotor by forming a magnetic thin film on at least a part of the printed wiring type air-core armature coil. Stator.   The wound type air-core armature coil is disposed on the first surface of the printed wiring board, and the printed-wire type air core armature coil is at least partially formed on the second surface, The magnetic thin film is formed by magnetic plating, and a drive circuit member is arranged on the first surface of the printed wiring board so as not to overlap with the wound air-core armature coil in plan view. A stator having the detent torque generating means according to claim 1. Rotor and the axial air-gap type magnet which is held in a certain thickness rotor yoke and said rotor yoke in 0.2mm below to combine the stator according to claim 1 or 2, disposed on the rotor yoke at the outside of the magnet An axial gap type brushless motor comprising an eccentric weight and rotatably stored in a yoke bracket and a cover member via a shaft.

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