KR100568289B1 - Vibration Motor Including U-type Bended Brush - Google Patents

Abstract

The vibration motor according to the present invention includes a stator, a rotor, a shaft, and a brush extending in a predetermined length to one side and bent in a U shape. One end of the brush is fixed to the lower substrate of the stator, extends from the one end by a certain length, and is bent in a U-shape on the opposite side so that the uppermost end of the brush selectively contacts the commutator substrate to apply current.

Brush, Vibration Motor, Stator, Rotor

Description

Vibration motor with U-shaped bend brush {Vibration Motor Including U-type Bended Brush}             

1 is an exploded perspective view of a general coin type vibration motor.

Figure 2 is a side cross-sectional view of a vibration motor having a conventional brush.

3 is an enlarged perspective view of a conventional brush.

Figure 4 is a side cross-sectional view of a vibration motor having a brush bent in a U-shape according to the present invention.

5 is an enlarged perspective view of a brush bent in a U-shape according to the present invention.

6 is a reference diagram for measuring the height change of the brush.

* Description of the symbols for the main parts of the drawings *

100 ... Coin type vibration motor 10 ... Stator

11 ... bracket 12 ... lower board

13 ... Magnet 14 ... Shaft

15 ... Conventional Brush 20 ... Rotor

21 Bearing 22 Coil Assembly

23 ... weight 24 ... commutator substrate

25 ... upper substrate 26 ... insulator

30 ... Case 40 ... U-shaped bent brush

A ... once fixed of brush C ... top of brush

B ... U-shaped bending part D ... U-shaped bending part and gap between lower board

The present invention relates to a vibration motor having a brush bent in a U-shape, and more particularly, U-shaped to ensure the length of the brush while reducing the size of the vibration motor according to the trend of thinning and miniaturization of communication equipment It relates to a vibration motor having a brush bent to.

In general, one of the essential functions of a communication device is an incoming call function, and a type commonly used as the incoming call function is a voice function such as a melody or a bell and a vibration function to shake the device.

Among them, the vibration function is mainly used when a melody or bell is transmitted to the outside through a speaker so as not to cause damage to others. For this vibration, it is common to drive a small vibration motor so that the driving force is transmitted to the case of the device so that the device can vibrate.

Vibration motors currently applied to mobile phones are classified into coin type and cylinder type according to the shape of the motor. Among them, in the case of a coin-type vibration motor, it is possible to generate vibrations with a relatively simple structure, such as placing a weight in the motor and rotating it. In particular, the coin-type vibration motor has a number of advantages, such as being able to manufacture a thin thickness and advantageous in miniaturization of mobile phone components, the use range is gradually increasing.

FIG. 1 illustrates an exploded detailed coin type vibration motor, which will be described below.

Coin-type vibration motor 100 is composed of a stator assembly (10, stator assembly) and a rotor (20, rotor assembly) is largely a fixed member.

That is, the stator 10 has a lower substrate 12 bonded to an upper surface of a bracket 11, which is a circular flat plate, and has an annular magnet 13 having a concentric circle on an outer side of the lower substrate 12. ) Is attached and formed in the same manner. The upper part of the bracket 11 is covered by a case 30, and the bracket 11 and the case 30 are connected by a central shaft 14.

The shaft 14 is provided with a rotor 20 to be rotatable as shown in FIG. 2, wherein the rotor 20 again bears a bearing 21 and a coil assembly 22. And a counter weight 23, a commutator substrate 24, an upper substrate 25, and an insulator 26.

The upper substrate 25 is a printed circuit board formed in a circular shape. When power is applied from the commutator substrate 24 attached to the bottom surface, the upper substrate 25 is connected to the coil assembly 22 through a pattern formed on the upper and lower surfaces of the upper substrate 25. It will supply another power source. The commutator substrate 24 is embedded in the bottom surface of the upper substrate 25 so that the contact surface is exposed while forming a plurality of segments circularly at regular intervals in the peripheral portion of the rotation center side. The coil assembly 22 is provided as at least one coil which is located to correspond to each other within the same rotation radius on the vertical line and the magnet 13 at the bottom, and is supplied with power of different polarities by the upper substrate 25.

The weight body 23 is usually made of a material having a high specific gravity, such as tungsten, attached to the direction corresponding to the coil 22 provided on the upper substrate 25 to determine the amount of eccentricity of the motor. On the other hand, the insulator 26 allows the bearing 21, the coil assembly 22, and the weight body 23 to be firmly coupled to each other on the upper substrate 25, and is configured for insulation.

At this time, the stator 10 and the rotor 20 are electrically connected to the lower substrate 12 by a brush 15 having a lower end fixed thereto and an upper end thereof contacting the commutator substrate 24. The vibration motor as described above is called a brush type vibration motor, and the brush will be described in detail below.

Figure 2 shows a side cross-sectional view of a vibration motor having a conventional brush, Figure 3 shows an enlarged conventional brush, which will be described as follows.

In general, in the brush type vibration motor, the brush 15 is configured such that one end A is fixed to the lower substrate 12 by brazing and the upper end C of the other end is in contact with the commutator substrate 24 to apply current. Electrically connect the stator and the rotor.

The brush 15 acts as a spring (spring) having a predetermined shape, mainly made of copper alloy and the part in contact with the commutator substrate 24 is covered with gold plating or precious metal to ensure electrical conductivity.

In addition, two or more brushes 15 are typically installed to transmit positive and negative poles, and the left and right brushes are symmetrically designed to be positioned on the same trajectory.

In order to smooth the commutation of the motor in such a brush type vibration motor, it is very important that the proper stress of the brush 15 is maintained and always in contact with the commutator substrate 24.

Recently, as the size of the communication device becomes thinner and smaller, the size of the vibrating motor decreases, which reduces the inner diameter of the magnet of the stator.

However, in order to prevent sagging of the brush and to maintain the adaptive pressure, an appropriate length of the brush must be secured. In the conventional brush type as shown in FIG. 2 or 3, there is no other method unless the magnet inner diameter is enlarged. However, this method is problematic because it can lead to a decrease in the efficiency of the motor.

In addition, in the case of external impact such as a drop impact or a thermal shock, the shorter the length of the brush, the smaller the spring deflection, the less the deflection of the brush, the brush deflection phenomenon, the brush smoothly contacts the commutator substrate. There is a problem that the electrical connection between the stator and the rotor is not good.

In addition, as the length of the brush becomes shorter, the stress is concentrated, and as the magnitude of the stress as a whole becomes large, the proper stress cannot be maintained, resulting in electrical and mechanical wear of the brush.

Therefore, in order to prevent the above problems, there has been a need in the art for a vibration motor capable of preventing the brush from sagging by securing an appropriate length of the brush without changing the inner diameter of the magnet.

The present invention is to solve the conventional problems as described above, while minimizing and thinning the vibration motor, while ensuring the proper length of the brush, bent in a U-shaped brush to prevent the deflection phenomenon of the brush The purpose is to provide a vibration motor having a.

The present invention to solve the above object is a stator having a lower substrate bonded to the ring-shaped magnet; A rotor having an eccentric weight and having a bottom commutator substrate and a coil assembly configured to generate an electromagnetic force by receiving current from the commutator substrate; A shaft having one end fixed to the center of the stator and the other end inserted into the center of rotation of the rotor; And a brush, one end of which is fixed to the lower substrate of the stator, extending from the one end by a certain length, and bent in a U-shape to the opposite side so that the top of the end is selectively in contact with the commutator substrate to apply a current; It provides a vibration motor comprising a.

The U-shaped bending part of the brush is characterized in that to maintain a predetermined distance from the lower substrate of the stator. At this time, it is preferable that the U-shaped bending part and the lower substrate of the stator maintain an interval of about 0.05 mm to 0.25 mm.

Here, the brush is horizontally extended by a predetermined length from one end to the one side, the end of the brush is characterized in that it is formed to have a predetermined angle with respect to the horizontal extension after bending in a U-shape. At this time, the end of the brush is preferably 15 to 70 ° with respect to the horizontal extension.

The brush is fixed at one end to the lower substrate of the stator, extends from the one end by a certain length, and bent in a U-shape to the opposite side, and the top of the end is selectively connected to the commutator substrate at the upper side of the one end. It is characterized in that the contact.

In addition, the vibration motor according to the present invention may further include a case for sealing the upper portion of the stator to form an inner space.

In addition, the rotor may include a weight body, a bearing coupled to the center of rotation to contact the outer circumferential surface of the shaft, and an insulator for insulating the coil assembly, the weight body, the bearing, and the like, together with each other, on the upper substrate for insulation. It is preferable to further include.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 is a side cross-sectional view of a vibration motor having a brush bent in a U-shape according to the present invention, Figure 5 shows a brush bent in a U-shape in detail, as follows.

The vibration motor according to the present invention may include a stator 10, a rotor 20, a shaft 14, and a brush 40. In addition, the vibration motor may further include a case 30 for sealing an upper portion of the stator and forming an inner space.

The stator 10 is preferably formed by bonding the lower substrate 12 to the upper surface of the circular bracket 11 and the annular magnet 13 having concentric circles to the outer upper surface of the lower substrate. Do.

The rotor 20 has an eccentric weight and has a plurality of coil assemblies 22 spaced apart from each other at a predetermined angle on an upper surface, a commutator substrate 24 formed on a bottom surface thereof, and an insulator 26 for fixing them. It may include. In addition, the rotor preferably further includes a weight body (23).

The shaft 14 has one end fixed to the center of the stator, the other end is inserted into the center of rotation of the rotor, the rotor 21 is coupled to the center of rotation so that the rotor is in contact with the outer peripheral surface of the shaft 21 It may further include.

Brush 40 according to the present invention is one end (A) is fixed to the lower substrate of the stator by a lead, extends by a certain length from the one end (A), bent in a U-shaped to the opposite side, the U-shaped The uppermost portion C of the brush tip connected from the bending portion B may be formed to selectively contact the commutator substrate 24 to apply a current.

The brush is bent at a predetermined angle from the one end (A) and then extends horizontally by a predetermined length to one side, and the end of the brush is formed to have a predetermined angle with respect to the horizontal extension after bending the U-shape. Can be. At this time, the end of the brush is preferably 15 ~ 70 °, and most preferably 40 ° with respect to the horizontal extension. This is for the design of optimized dimensions in the limited space according to the trend of miniaturization and separation of communication devices.

More specifically, the brush 40 is one end (A) is fixed to the lower substrate of the stator, extends by a certain length from one end to one side, bent in a U-shape to the opposite side, and then the uppermost (C) of the end ) Is formed to be selectively in contact with the commutator substrate above the one end (A).

Brush 40 according to the present invention as described above has a feature that can be appropriately increased the length by bending and extending in a U-shape in a narrow space according to the trend of miniaturization, thinning of the communication device. In addition, the stress concentration of the brush is alleviated and the magnitude of the stress is reduced as a whole, so that there is an effect that the elasticity can be maintained without plastic deformation even with a larger external impact.

Further, the U-shaped bending portion B of the brush 40 preferably maintains a predetermined distance D from the lower substrate 12 of the stator. This is to absorb the impact while the brush is deformed by the predetermined interval (D) during the drop impact, thereby preventing sagging of the brush, especially in the case of a drop impact.

At this time, it is preferable that the U-shaped bending part and the lower substrate of the stator maintain an interval of about 0.05 mm to 0.25 mm.

As described above, the vibration motor having the brush 40 as described above may maintain the stress of the left and right brushes uniformly, prevent the brush sag, and generate a smooth rectification without generating noise during rotation.

Measurement results for the spring deflection, spring stress force and the height change of the brush after the test of the U-bent brush and the conventional brush according to the present invention configured as described above are as follows: .

First, the spring equation for measuring the elastic deformation of the brush acting as a spring is as follows.

[Equation 1]

Where s (mm) = elastic deformation, F = elastic stress (gf), L = brush length (mm), E = modulus of elasticity, b = width of brush (mm), T = thickness of brush (mm) is shown. Using the spring equation it is possible to calculate the elastic deformation amount and the elastic stress for each brush length.

In this experiment, the length of the brush of the conventional type and the brush bent in a U shape according to the present invention, about 4.75 mm, about 6.35 mm were used, respectively. At this time, the width and thickness of the brush of the conventional form and the brush brush bent in a U-shape according to the present invention were all made constant.

Substituting this into Equation 1 results in the following calculations.

TABLE 1

As can be seen in Table 1, the elastic deformation amount of the U-shaped bend brush according to the present invention is 0.91 mm, 0.38 mm of the conventional type brush compared to the elastic deformation amount of about 230%.

That is, in the case of external impact, the amount of elastic deformation of the brush increases as the amount of elastic deformation increases, so that the brush may be restored to its initial position after the impact. Therefore, the present invention in which the length of the brush is appropriately extended by providing a U-shaped bending part can prevent the brush deflection phenomenon by increasing the amount of elastic deformation.

In addition, the elastic stress of the U-shaped bent brush according to the present invention is 0.5 gf, the elastic stress is about 30% reduced compared to 1.7 gf of the conventional brush. In other words, as the length of the brush becomes longer, the stress concentration phenomenon of the brush is alleviated and the magnitude of the stress of the entire brush becomes smaller. Therefore, the proper stress of the brush is maintained, so that the brush can be elastically maintained without being plastically deformed, and thus will be restored to the initial position after the impact.

In addition, when an external impact is applied to the brush, when the brush height change (difference between the initial height and the post-impact height) becomes greater than the amount of elastic deformation, the brush does not recover to the initial proper position and causes brush deflection. In addition, the deflection of the brush prevents smooth rectification and is a major cause of deterioration of the vibration motor performance.

In order to determine the puncture phenomenon of the brush, as shown in FIG. 6, the initial height (a) of the brush was measured, and after the drop impact test using a weight of a constant weight, the height (b) after the test was measured. As a result, the brush of the conventional type was 1.9 mm in initial height and 1.69 mm in height after the test, and the brush bent in a U shape according to the present invention was initially 2.0 mm and 2.0 mm in height after the test.

That is, the conventional brush is 0.21 mm in height difference is smaller than the elastic deformation amount of 0.38 mm, but the difference is not large, the larger the external impact will be inevitable brush deflection phenomenon.

On the contrary, the brush bent in a U shape according to the present invention had no height difference before and after the test.

Therefore, the brush bent in a U shape according to the present invention was found to be almost completely prevented from sagging of the brush because there is no change in brush height before and after the test.

As such, the present invention has the advantage of not only preventing the deflection of the brush by increasing the amount of elastic deformation by appropriately increasing the length of the brush, but also ensuring the proper elastic stress of the brush.

The above has been described in detail with reference to the present invention, which is illustrative and does not limit the present invention.

Vibration motor having a brush bent in the U-shape according to the present invention, while reducing the size of the vibration motor in accordance with the trend of thinning, miniaturization of communication devices, it is effective to secure the appropriate length of the brush in a narrow space have.

In addition, according to the present invention, the length of the brush can be appropriately increased, thereby increasing the amount of elastic deformation and optimizing the elastic stress to prevent brush deflection, as well as minimizing the electrical and mechanical wear of the brush. .

Moreover, the present invention has the effect of preventing the brush sag phenomenon to improve the performance of the vibration motor and to extend the life.

Claims (20)

A stator having a lower substrate to which an annular magnet is bonded; A rotor having an eccentric weight and having a bottom commutator substrate and a coil assembly configured to generate an electromagnetic force by receiving current from the commutator substrate; A shaft having one end fixed to the center of the stator and the other end inserted into the center of rotation of the rotor; And One end of which is fixed to the lower substrate of the stator, extends from the one end by a certain length, and bends in a U-shape to the other side, and is positioned on a substantially same vertical axis as the point where one end is fixed to the lower substrate. A brush, the top of which is in selective contact with the commutator substrate to apply current; Vibration motor comprising a. The method of claim 1, And the U-shaped bending part of the brush maintains a predetermined distance from the lower substrate of the stator. The method of claim 2, The U-shaped bending part of the brush is a vibration motor, characterized in that to maintain a distance of 0.05 mm ~ 0.25 mm with the lower substrate of the stator. The method of claim 1, The brush is bent from the one end and is extended horizontally by a predetermined length to one side, the end of the brush is bent in a U-shaped vibration motor, characterized in that it is formed to have a predetermined angle with respect to the horizontal extension. The method of claim 4, wherein The end of the brush is bent in a U-shaped vibration motor, characterized in that it is formed to have an angle of 15 ~ 70 ° with respect to the horizontal extension. The method of claim 1, The brush is fixed at one end to the lower substrate of the stator, extends from the one end by a certain length, and bent in a U-shape to the opposite side, and the top of the end is selectively connected to the commutator substrate at the upper side of the one end. Vibration motor, characterized in that the contact. The method of claim 1, Vibration motor, characterized in that it further comprises a case for sealing the top of the stator to form an inner space. The method of claim 1, The rotor further comprises a weight body vibration motor. The method of claim 1, The rotor further comprises a bearing coupled to the center of rotation to contact the outer peripheral surface of the shaft. The method of claim 1, And the rotor further comprises an insulator which allows the coil assembly, the weight body and the bearing to be firmly coupled to each other on the upper substrate for insulation. A stator having a lower substrate bonded to an annular magnet, A rotor having an eccentric weight and having a bottom commutator substrate and a coil assembly configured to generate an electromagnetic force by receiving current from the commutator substrate; A shaft having one end fixed to the center of the stator and the other end inserted into the center of rotation of the rotor; One end of which is fixed to the lower substrate of the stator, extends from the one end by a certain length, and is bent to the opposite side, the uppermost end of which is located on the same vertical axis as the point where the one end is fixed to the lower substrate; A vibration motor comprising a brush for selectively applying a current in contact with the commutator substrate. The method of claim 11, And the bending part of the brush maintains a predetermined distance from a lower substrate of the stator. The method of claim 12, And the bending part of the brush maintains a distance of 0.05 mm to 0.25 mm from a lower substrate of the stator. The method of claim 11, The brush is bent from the one end and is extended horizontally by a predetermined length to one side, the end of the brush is bent in a U-shaped vibration motor, characterized in that it is formed to have a predetermined angle with respect to the horizontal extension. The method of claim 14, The end of the brush is bent in a U-shaped vibration motor, characterized in that it is formed to have an angle of 15 ~ 70 ° with respect to the horizontal extension. The method of claim 11, The brush is fixed at one end to the lower substrate of the stator, extends from the one end by a certain length, and bent in a U-shape to the opposite side, and the top of the end is selectively connected to the commutator substrate at the upper side of the one end. Vibration motor, characterized in that the contact. The method of claim 11, Vibration motor, characterized in that it further comprises a case for sealing the top of the stator to form an inner space. The method of claim 11, The rotor is characterized in that the vibration motor further comprises a weight body The method of claim 11, The rotor further comprises a bearing coupled to the center of rotation to contact the outer peripheral surface of the shaft. The method of claim 11, And the rotor further comprises an insulator which allows the coil assembly, the weight body and the bearing to be firmly coupled to each other on the upper substrate for insulation.

Images