JPH06205565A - Flat coreless vibration motor - Google Patents

Abstract

PURPOSE:To obtain sufficient vibration effectively with a small current by arranging three armature coils of rotor with a bias so that these coils are not overlapped and the plane becomes almost sector shape. CONSTITUTION:Three armature coils 9a, 9b, 9c of rotor R of a flat motor are arranged with a bias so that these are not overlapped and the plane becomes almost a sector shape. Therefore, the rotor R itself is eccentric to a large extent. Moreover, arrangement angle (arrangement pitch) of the one of the armature coils 9a, 9b, 9c is set to almost 60 to 80 degrees. Thereby, a large centrifugal force can be obtained while the rotor R is rotating and sufficient vibration can also be obtained efficiently with a small current.

Description

Description: TECHNICAL FIELD The present invention relates to a flat coreless vibration motor suitable as a silent notification source for a card-type portable device. (Prior Art) A conventional flat coreless vibration motor is disclosed, for example, in 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 ° are 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. (Problems to be solved) However, it is difficult to reduce the thickness of the output shaft provided with the eccentric plate, and the output shaft is divided into three parts.
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,
This invention has a drawback that it causes unpleasant vibrations, and in the case where 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 in order to solve the above problems, and an object thereof is to provide a flat coreless vibration motor which is suitable as a notification source for a card-type portable device, has a small thickness, consumes less current, and is highly efficient. (Means for Solving the Problems) A flat motor according to the present invention is a rotor in which at least three armature coils are biased so as not to overlap each other and have a substantially fan-shaped plane. A shaft that is arranged in an essential manner, a flat plate commutator that is arranged on the rotor so as to be concentric with the shaft, a magnet that faces the rotor, and a brush that is arranged inside the magnet and is in sliding contact with the flat plate commutator. The armature coil is preferably composed of three, and the arrangement opening angle (arrangement pitch) per one of the armature coils is set to approximately 60 ° to 80 °. More preferably, the shaft does not project outward. (Operation) With this configuration, since the rotor itself is largely eccentric, a large centrifugal force is generated during rotation. Also,
Since it is not necessary to project the shaft to the outside, it can be made extremely thin, and the arrangement opening angle (arrangement pitch) per one of the three armature coils is set to 60 ° to 80 °, which is less efficient. Sufficient vibration can be obtained with an electric current, and the shaft is prevented from protruding outward, so it can be made extremely thin. (Embodiment) An embodiment 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 shows the rotor R of this flat coreless vibration motor.
In a plan view of three armature coils 9a, 9b and 9c
Is characterized in that they are biased to one side at an opening angle of about 75 °. In this case, this armature coil 9a,
In 9b and 9c, the conductor portions that contribute to the generation of torque are brought as close as possible to the reference electric opening angle (90 °), which is equal to the magnetizing opening angle of the magnet, so that the winding opening angle is set within one arrangement opening angle. You should spread it as much as you can. 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 just at the center of the fan. In addition, the armature coil 9
A, 9b and 9c are pre-connected inside the rotor by delta or star connection. 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 magnetized so as to be equally poled alternately in NS, and the armature coil 9 of the rotor R is magnetized.
The terminals a, 9b, and 9c are connected to the respective segments 10a, 10b, 10c, 10d, 10e, and 10f of the commutator 10, and through the through holes so that the segments of 180 ° facing each other have the same potential. Wired on the back side. Reference numerals 6a and 6b are positive and negative brush pieces, respectively, which are pressed against the segments 10a ... 10f at an electrical angle of 90 °. Arrow A is the direction of rotation of the rotor. Now, when power is supplied to the brush pieces 6a and 6b by a required power source (not shown), the rotor first becomes "0".
At the “°” position, current flows through the armature coils 9a, 9b, and 9c in the direction of the arrow, so that the rotor generates torque in the direction of arrow A according to Fleming's left-hand rule. After that, the rotation progresses and “30 °” and “6” respectively.
Similarly, in the case of 0 °, “90 °”, and “120 °”, rotation occurs in the direction of arrow A, but in other cases as well, the anti-torque that prevents 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 method, but it goes without saying that the same function as described above can be achieved in this method as well. 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, (1)
Since at least three armature coils are arranged so as not to overlap each other and are eccentrically arranged so that their planes are substantially fan-shaped, the rotor itself is largely eccentric, so that a large centrifugal force can be obtained during rotation. Therefore, the eccentric plate is not necessary, and the commutator is a flat plate type, so that it can be made extremely thin. (2) Since the opening angle of the armature coil is set to 60 ° to 80 °, sufficient vibration can be efficiently obtained with a small current. (3) Since the shaft does not protrude to the outside, it can be made thin, easy to handle, and not dangerous. Therefore, it is useful as a notification source due to vibration of the card type portable device.

BRIEF DESCRIPTION OF THE 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, a shaft 8 is a holder 9a, 9b, 9c is an armature coil 10 is a flat plate commutator 10a, 10b ... 10f, the segment 11 is a synthetic resin 12a, 12b is an oil-impregnated bearing 13a, 13b is a slider R is a rotor.

Claims (1)

Claims: (1) A rotor in which at least three armature coils are arranged so as not to overlap with each other, and the planes of which are substantially fan-shaped, and a shaft arranged at the center of the rotor. ,
A flat plate commutator disposed on the rotor so as to be concentric with the shaft, and a magnet facing the rotor,
A flat coreless vibration motor comprising a brush disposed inside the magnet and in sliding contact with the flat plate commutator, and a casing accommodating the brushes. (2) The armature coil is composed of three pieces, and the arrangement opening angle (arrangement pitch) per one armature coil is about 60.
The flat coreless vibration motor according to claim 1, wherein the flat coreless vibration motor has a rotation angle of 80 °. (3) The flat coreless vibration motor according to claim 1 or 2, wherein the shaft does not protrude outward.