JP2006180571A - Vibrating motor electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibrating motor in which the size can be reduced even in case of a tubular vibrating motor and the degree of freedom can be enhanced in design on the apparatus side, and to provide an electronic apparatus mounting it. <P>SOLUTION: A case 1 containing a stator 11 and a rotor 12 supports the rotor 12 rotatably while touching the outer circumferential surface 4b of the rotor 12 (outer circumferential surface 4b of a rotor yoke 4). More specifically, the case 1 itself accomplish the function of bearing of the rotor 12. Consequently, the size can be reduced as compared with a conventional vibrating motor having such a structure as the vibrating portion (motor shaft and weight) is exposed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vibration motor that generates vibrations and an electronic apparatus equipped with the vibration motor.

  2. Description of the Related Art Conventionally, there are many devices in which a vibration motor is mounted on a device such as a mobile phone device in order to exhibit a vibration function. As a vibration motor, for example, a general cylindrical vibration motor is employed. In this vibration motor, a weight that forms an unbalance is attached to the tip of a rotating shaft extending from the motor body, and the weight is rotated to generate vibration in the rotational radial direction of the motor.

In recent years, flat type vibration motors have been used with the thinness of devices such as mobile phone devices (see, for example, Patent Document 1). Among flat vibration motors, brushless vibration motors have also appeared, improving durability and reliability. In the vibration motor described in the above-mentioned Patent Document 1, a disc-shaped magnet that is a part of the rotor is partially cut out to form an unbalance.
JP 2002-248428 A (paragraph [0008], FIG. 1)

  However, in the case of a cylindrical vibration motor, the vibration part consisting of the rotation shaft and the weight is exposed from the motor body. Therefore, when this vibration motor is incorporated in a device, the space around the exposed vibration part is reduced. There is an inconvenience that it must be arranged widely, and it is difficult to reduce the size of the device. In addition, with such a configuration of the vibration motor, the designer must consider the position, orientation, etc. when the vibration motor is installed in the device, which reduces the degree of design freedom on the device side. There is.

  On the other hand, it is conceivable that the above-described flat vibration motor is employed in order to reduce the size of a device on which the vibration motor is mounted. However, when a flat vibration motor is mounted on, for example, a thin electronic device, the vibration direction of the motor tends to vibrate in a plane perpendicular to the thickness direction of the thin device, and the user feels vibration. There is a characteristic that vibration in the thickness direction, which is easy to occur, hardly occurs. Accordingly, this makes the device less susceptible to vibration.

  In view of the circumstances as described above, an object of the present invention is to achieve a reduction in size even with a cylindrical vibration motor, and to mount a vibration motor capable of increasing the degree of freedom in designing on the equipment side. Is to provide an electronic device.

  In order to achieve the above object, a vibration motor according to the present invention includes a stator having a coil on the outer periphery, an outer peripheral surface, and a magnet that is disposed opposite to the coil and that is eccentric about the stator as an axis. And a rotor that rotates around the stator when the coil is energized, and a case that accommodates the stator and the rotor and rotatably supports the rotor while being in contact with the outer peripheral surface of the rotor.

  In the present invention, the case housing the stator and the rotor rotatably supports the rotor while being in contact with the outer peripheral surface of the rotor having the eccentric magnet. can do. Further, for example, even when the vibration motor according to the present invention is mounted on an electronic device, the electronic device can be downsized and the degree of design freedom on the device side can be increased.

  According to an aspect of the present invention, the rotor includes a cylindrical holding member having an inner peripheral surface capable of holding the magnet and the outer peripheral surface. According to such a cylindrical holding member, the outer peripheral surface of the holding member, that is, all the surfaces in the circumferential direction are in contact with the case, so that the rotor can rotate stably while generating vibration. This holding member can also function as a yoke constituting a magnetic circuit, for example.

  According to one aspect of the present invention, the holding member is made of a sintered oil-impregnated metal or a resin having self-lubricating properties. As a result, the rotor can rotate more stably while generating vibrations. In particular, when the holding member is a sintered oil-impregnated metal, the oil contained in the holding member oozes out to the outer peripheral surface due to the centrifugal force caused by the rotation of the rotor, so that the lubricity between the holding member and the case can be further improved. As the resin having self-lubricating property, for example, POM (polyoxymethylene (polyacetal)), PAI (polyamideimide) or the like is used.

  According to one aspect of the present invention, the magnet forms a cylindrical first portion, and the rotor forms a remaining second portion other than the first portion of the cylindrical magnet, A member having a specific gravity different from that of the magnet, an inner peripheral surface capable of holding the magnet and the member, and a cylindrical holding member having the outer peripheral surface. According to such a cylindrical holding member, the outer peripheral surface of the holding member, that is, all the surfaces in the circumferential direction are in contact with the case, so that the rotor can rotate stably while generating vibration. The members having different specific gravities need only be able to form an eccentric magnet, that is, an unbalance, and may be metal, resin, or other materials.

  According to an aspect of the present invention, the rotor includes a cylindrical holding member that covers an outer periphery of the magnet so that the magnet is embedded and has the outer peripheral surface. For example, the holding member can be integrally formed so that the magnet is embedded. Also in this case, as described above, the holding member may be a sintered oil-impregnated metal or a resin having self-lubricating properties.

  An electronic apparatus according to the present invention includes a stator having a coil on the outer periphery, a magnet that is disposed opposite to the coil and that is eccentric with respect to the stator as an axis, and the stator is energized when the coil is energized. A vibration motor having a rotor rotating around, a stator that houses the stator and the rotor, and rotatably supports the rotor so as to be in contact with the rotor; and a housing that houses the vibration motor. .

  According to the present invention, the case accommodating the stator and the rotor rotatably supports the rotor while being in contact with the outer peripheral surface of the rotor having the eccentric magnet. Therefore, the vibration motor and the electronic device can be reduced in size. . Examples of the electronic device include a mobile phone device, a PDA (Personal Digital Assistance), a watch, a pager, and other portable electronic devices. The same applies hereinafter.

  As described above, according to the present invention, even a cylindrical vibration motor can be reduced in size, and the degree of design freedom on the electronic device side on which the vibration motor is mounted can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a vibration motor according to an embodiment of the present invention. FIG. 2 is a perspective view from below of the vibration motor shown in FIG. FIG. 3 is a sectional view of the vibration motor, and FIG. 4 is an exploded perspective view of the vibration motor.

  The vibration motor 10 includes, for example, a cylindrical case 1. As shown in FIG. 3, the case 1 houses a rotor 12 that rotates around the stator 11 and the shaft-shaped stator yoke 2 as axes. The case 1 is made of, for example, resin, and the outer diameter of the case 1 is, for example, 3 mm to 10 mm, but is not limited thereto.

  FIG. 5 is a perspective view showing a part of the stator 11 and the substrate. The stator 11 includes the cylindrical stator yoke 2 and, for example, a coil 5 provided on the outer periphery 2c of the stator yoke 2. Although the coil 5 is schematically illustrated, in practice, for example, a cage coil is used. Although not shown in FIG. 5, the stator 11 includes a dish-shaped stator base 6 as shown in FIGS. 3 and 4, and the stator base 6 has an opening 1 b provided at one end of the case 1. And is fixed to the case 1. The stator yoke 2, the stator base 6, and the rotor yoke 4 of the rotor 12 described later are each made of a magnetic material, and these constitute a magnetic circuit for generating the rotational driving force of the rotor 12.

  The stator base 6 is provided with a plurality of holes 6a, and lead wires 5a drawn from the coils 5 are inserted into the holes 6a. The lead wire 5 a is electrically connected to a substrate 8 attached to the lower surface of the stator base 6 and an IC (Integrated Circuit) that is mounted on the substrate 8 and controls the rotational drive of the rotor 12.

  FIG. 6 is a perspective view showing the rotor 12. The rotor 12 is configured, for example, by holding the magnet 3 on the inner peripheral surface of a cylindrical rotor yoke 4. The magnet 3 is magnetized in such a direction that both poles are divided and arranged in the rotational direction, for example. The magnet 3 has a shape such that a part of a cylindrical shape is cut out, and thereby, eccentrically forms an unbalance. As a result, when the rotor 12 rotates, vibration is generated in the rotation plane, that is, in a plane substantially perpendicular to the rotation axis.

  As shown in FIG. 3, the stator yoke 2 is fixed to the case 1 by fitting a protrusion 2 a provided at one end of the stator yoke 2 into the hole 1 a of the case 1. Further, the projection 2 b provided at the other end of the stator yoke 2 is fitted into the hole 6 b of the stator base 6, so that the stator yoke 2 and the stator base 6 are fixed. The rotor 12 is arranged so that the magnet 3 faces the coil 5 attached to the stator yoke 2 with a gap, and the outer peripheral surface of the rotor yoke 4 is in contact with the inner peripheral surface 1 c of the case 1. .

  The rotor yoke 4 is made of, for example, a sintered oil-impregnated metal. Thereby, the oil contained in the rotor yoke 4 oozes out to the outer peripheral surface 4b by the centrifugal force generated by the rotation of the rotor 12, so that the lubricity between the rotor yoke 4 and the case 1 can be improved. Alternatively, a resin material having excellent wear resistance, mechanical characteristics, and self-lubricating properties such as POM or PAI may be used for the rotor yoke 4.

  With such a configuration of the vibration motor 10, when the coil 5 is energized under the control of the IC 7, the outer peripheral surface 4 b of the rotor yoke 4 is in sliding contact with the inner peripheral surface 1 c of the case 1, and the rotor 12 is connected to the stator yoke 2. Rotate around the axis. Vibrations are generated in the vibration motor 10 by the rotation of the rotor 12.

  As shown in FIG. 7, the conventional cylindrical vibration motor 10 has a weight 102 for eccentricity attached to a motor shaft 101 extending from the motor body 100.

  However, according to the vibration motor 10 according to the present embodiment, the case 1 housing the stator 11 and the rotor 12 can rotate the rotor 12 while being in contact with the outer peripheral surface 4b of the rotor 12 (the outer peripheral surface 4b of the rotor yoke 4). I try to support it. That is, the case 1 itself functions as a bearing for the rotor 12. Therefore, as shown in FIG. 7, the present embodiment can achieve a reduction in size as compared with a conventional vibration motor having a structure in which the vibration portion (the motor shaft 101 and the weight 102) is exposed. Further, even when the vibration motor 10 according to the present embodiment is mounted on an electronic device (not shown), it is possible to reduce the size of the electronic device and increase the degree of design freedom on the device side.

  FIG. 8 is a perspective view showing another embodiment of the unbalanced portion. The unbalance part 25 has a cylindrical shape. The unbalanced portion 25 is composed of a portion composed of the magnet 13 and a portion other than the cylindrical magnet 13 and composed of a material 14 having a specific gravity different from that of the magnet 13, for example, resin or metal. For example, it can be integrally formed. The unbalanced portion 25 is held on the inner peripheral surface 4 a of the rotor yoke 4 described above and is accommodated in the case 1. As the portion 14, for example, tungsten or the like can be used in a portion of 60 ° of the entire 360 °. Even with such a configuration, the rotor can be unbalanced.

  FIG. 9 is a perspective view showing a rotor according to another embodiment. The rotor 35 is configured by embedding a magnet 23 having a shape in which a part of the cylinder is cut out so that the outer periphery is covered with the cylindrical member 16. The rotor 35 can be integrally formed, for example. In this case, the weight and arrangement of the magnet 23 and the member 16 are set so that the weight of the entire rotor 35 is eccentric. The outer peripheral surface 16 a of the member 16 rotates while contacting the inner peripheral surface 1 c of the case 1. The cylindrical member 16 can be formed by, for example, POM or PAI. Alternatively, the member 16 may be a metal.

  The present invention is not limited to the embodiment described above, and various modifications are possible.

  For example, the outer shape of the case 1 shown in FIG. However, if the inner peripheral surface of the case is cylindrical, the outer shape may be a prismatic shape or other shapes.

  For example, in FIG. 3, a member serving as a metal bearing may be interposed between the inner peripheral surface 1 c of the case 1 and the rotor yoke 4.

It is a perspective view which shows the vibration motor which concerns on one embodiment of this invention. It is a perspective view from the downward direction of the vibration motor shown in FIG. It is sectional drawing of the vibration motor shown in FIG. It is a disassembled perspective view of the vibration motor shown in FIG. It is a perspective view which shows a part of stator and a board | substrate. It is a perspective view which shows a rotor. It is a perspective view which shows the conventional cylindrical vibration motor. It is a perspective view which shows other embodiment of an unbalance part. It is a perspective view which shows the rotor which concerns on another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Case 1c ... Inner peripheral surface 2 ... Stator yoke 2c ... Outer periphery 3, 13, 23 ... Magnet 4 ... Rotor yoke 4a ... Inner peripheral surface 4b, 16a ... Outer peripheral surface 5 ... Coil 6 ... Stator base 10 ... Vibration motor 11 ... Stator 12, 35 ... Rotor

Claims (7)

A stator having an axial yoke and a coil provided on the outer periphery of the yoke;
A rotor that has an outer peripheral surface and a magnet that is disposed opposite to the coil and that is eccentric about the yoke as an axis, and that rotates around the stator when the coil is energized;
A vibration motor comprising: a case that accommodates the stator and the rotor and rotatably supports the rotor while being in contact with an outer peripheral surface of the rotor. The vibration motor according to claim 1,
The rotor is
A vibration motor comprising a cylindrical holding member having an inner peripheral surface capable of holding the magnet and the outer peripheral surface. The vibration motor according to claim 2,
The holding motor is made of sintered oil-impregnated metal or self-lubricating resin. The vibration motor according to claim 1,
The magnet forms a cylindrical first portion,
The rotor is
A remaining second portion other than the first portion in the cylindrical magnet, a member having a specific gravity different from that of the magnet;
A vibration motor comprising: an inner peripheral surface capable of holding the magnet and the member; and a cylindrical holding member having the outer peripheral surface. The vibration motor according to claim 1,
The rotor is
A vibration motor comprising a cylindrical holding member that covers an outer periphery of the magnet so that the magnet is embedded and has the outer peripheral surface. The vibration motor according to claim 5,
The holding motor is made of sintered oil-impregnated metal or self-lubricating resin. A stator having a shaft-shaped yoke, a coil provided on the outer periphery of the yoke, an outer peripheral surface, a magnet disposed opposite to the coil and decentered about the yoke as an axis; A vibration motor having a rotor that rotates around the stator when a coil is energized, and a case that accommodates the stator and the rotor and rotatably supports the rotor while being in contact with an outer peripheral surface of the rotor;
An electronic device comprising: a housing incorporating the vibration motor.

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