JPH0810972B2 - Flat coreless vibration motor - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat coreless vibration motor suitable as a silent notification source for card type portable equipment.

2. Description of the Related Art A conventional flat coreless vibration motor is disclosed in, for example, Japanese Patent Application No. 62-124640.
There is a normal rotation type rotor in which an eccentric plate is simply provided on the output shaft. Also, as a conventional flat coreless vibration motor,
Some of the three armature coils arranged at equal intervals of 20 ° may be partially removed or short-circuited. Such a vibration motor is disclosed in Japanese Patent Application No. 62-124640. Furthermore, there is a conventional flat coreless vibration motor in which one of three armature coils arranged on the rotor at an equal pitch of 120 ° is made smaller than the others. Such a vibration motor is disclosed in US Pat. No. 4,864,276.

However, it is difficult to reduce the thickness of the output shaft provided with the eccentric plate.
If a part of one armature coil is deleted or short-circuited, or one armature coil is made small, the centrifugal force generated at the time of rotation is small due to the disk shape as a whole,
The vibration is unpleasant, and if there are only two armature coils, it is not possible to take a large part that contributes to the generation of torque, and the current consumption is large and the efficiency is poor. The present invention has been made to solve the above problems, and an object of the present invention is to provide a flat coreless vibration motor that is suitable as a notification source for a card-type portable device and that is thin, consumes less current, and is highly efficient. And

A flat coreless vibration motor according to the present invention has at least three armature coils (9).
a, 9b, 9c) are arranged so as not to overlap each other,
A rotor (R) having a substantially fan-shaped plane as a whole
A shaft (7) arranged at the center of rotation of the rotor (R), and a flat plate commutator (10) arranged on the rotor (R) so as to be concentric with the shaft (7),
A magnet (3) facing the rotor (R) and the flat plate commutator (1) disposed inside the magnet (3).
The brush (6) is in sliding contact with the casing (0), and the casings (1, 2) for accommodating the brushes (6). The armature coil is composed of three pieces, and one of the armature coils is
Arrangement open angle (angle distribution pitch) per piece is approximately 60 ° to 80
Set to °.

By doing so, since the rotor itself is largely eccentric, a large centrifugal force is generated during rotation. Also,
The armature coil consisting of three pieces has an arrangement opening angle (orientation pitch) of 60 ° to 80 ° per one, and sufficient vibration can be efficiently obtained with a small current.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an essential part of a flat coreless vibration motor according to an embodiment of the present invention. That is, in the drawing, 1 is a case, and this case 1 is an upper portion 1a having a plane circular shape
And a shallow cylindrical skirt portion 1b extending downward from the outer peripheral portion of the upper portion 1a. Two
Is an end bracket fitted into the opening of the case 1, and the case and the bracket constitute a casing. Three
Is a ring-shaped rare earth magnet fitted inside the bracket, 4 is a thin brush base arranged inside the magnet 3, 5 is a brush terminal plate, 6 is a brush connected to the brush terminal plate 5, and 7 is a brush terminal plate. Is a shaft, 8 is a brass holder fitted on the shaft 7,
Reference numeral 9 is an armature coil, 10 is a plate-like commutator to which each terminal of the armature coil 9 is connected, 11 is the holder 8, synthetic resin such as glass fiber reinforced polyethylene terephthalate that integrates the armature coil 9, 12a, 12b is an oil-impregnated bearing that supports the shaft 7, and 13a and 13b are sliders. And R is a rotor. Here, the shaft 7 is prevented from projecting outward, and the brush 6 is elastically brought into contact with the flat plate commutator 10. FIG. 2 is a plan view of the rotor R of this flat coreless vibration motor, which shows three armature coils 9a, 9b and 9
It is characterized in that c is eccentrically arranged on one side at an opening angle of about 75 °. In this case, this armature coil 9
a, 9b, and 9c respectively make the conductor portions that contribute to the generation of torque as close as possible to the reference electric opening angle (90 °) equal to the magnetizing opening angle of the magnet, so that the winding opening is performed within one arrangement opening angle. It is good to open the corner as much as possible. Ideally, the winding angle of the winding axis of this coil is about 75 ° from the balance with the vibration amount. The rotor R is formed by molding the shaft 7, the holder 8, the armature coils 9a, 9b and 9c with synthetic resin 11 into a substantially fan shape as a whole, and the shaft 7 is arranged at the center of the fan which is the center of rotation. . Further, the armature coils 9a, 9b and 9c are preliminarily delta or star connected inside the rotor. Now, the rotation principle of the flat coreless vibration motor of the embodiment according to the present invention will be described by the delta connection method. In FIG. 3, the magnets 3 are arranged such that N and S are alternately and equally divided, and the rotor R
The terminals of the armature coils 9 a, 9 b and 9 c of the commutator 10 are connected to the respective segments 10 a, 10 b, 10 c, 1 of the commutator 10.
0d, 10e, and 10f are connected on the back side through the through holes so that the segments facing each other by 180 ° have the same potential. Again 6
a and 6b are positive and negative brush pieces, respectively, and have an electrical angle of 9
It is pressed against each of the segments 10a ... 10f at 0 °. Arrow A is the direction of rotation of the rotor. Now, when power is supplied to the brush pieces 6a and 6b from a required power source (not shown), first, when the rotor is at the position of "0 °", current flows through the armature coils 9a, 9b and 9c in the direction of the arrow. The rotor generates torque in the direction of arrow A according to Fleming's left-hand rule. After that, the rotation progresses, respectively, “30 °”, “60 °”, “90 °”, “120 °”
Also in the case of, the rotation similarly occurs in the direction of the arrow A, but in other cases, the anti-torque that prevents the rotation does not occur outward. Therefore, as long as the power is supplied, it is switched cyclically and continues to rotate. Next, FIG. 4 illustrates a rotation principle explanatory diagram of the star connection system, but it goes without saying that this system also performs the same function as described above. In addition, when taking an electrical neutral point, it is good to arrange the armature coils at equal intervals of 60 °, but it is not necessary to obtain an electrical neutral point because it is used for a vibrating body. It is possible to increase the substantial opening angle to improve the efficiency, but if it exceeds 80 °, it is difficult to maintain the imbalance and there is a dislike that the vibration does not increase.

As described above, according to the present invention, at least three armature coils are arranged so as not to overlap each other, and the plane is formed into a substantially fan shape as a whole. Since it itself is largely eccentric, a large centrifugal force is obtained during rotation, so the eccentric plate becomes unnecessary and the number of parts does not increase to obtain vibration,
Can be easily thinned together with a flat plate commutator. Also,
Since the opening angle of the armature coil is set to 60 ° to 80 °, there is an effect that sufficient vibration can be efficiently obtained with a small current. Therefore, it is useful as a notification source due to the vibration of the card type portable device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a flat coreless vibration motor according to an embodiment of the present invention. FIG. 2 is a sectional view of an essential part of a rotor of the flat coreless vibration motor. FIG. 3 is an explanatory diagram of the rotation principle of the flat coreless vibration motor in the delta connection system, and FIG. 4 is an explanatory diagram of the rotation principle of the star connection system. 1 is a case 2 is an end bracket 3 is a magnet 4 is a brush base 5 is a brush terminal plate 6 is a brush 6a, 6b is a brush piece 7 is a shaft 8 is a holder 9a, 9b, 9c is an armature coil 10 is a flat plate commutator 10a, 10b ... 10f are segments 11, synthetic resin 12a and 12b are oil-impregnated bearings 13a and 13b, slider R is a rotor.

Claims (2)

[Claims] 1. At least three armature coils (9a, 9)
b, 9c) are arranged so that they do not overlap each other, and the plane is generally fan-shaped as a whole, and a shaft (7) arranged at the center of rotation of the rotor (R).
A flat plate commutator (10) arranged on the rotor (R) so as to be concentric with the shaft (7), a magnet (3) facing the rotor (R), and an inside of the magnet (3). A flat coreless vibration motor comprising: a brush (6) which is arranged and is in sliding contact with the flat plate commutator (10); and casings (1, 2) for housing these. 2. The flat arm according to claim 1, wherein the armature coil is composed of three pieces, and the arrangement opening angle (angle arrangement pitch) per one armature coil is approximately 60 ° to 80 °. Coreless vibration motor.