KR100638665B1 - Brush For Preventing Droop And Electric Motor Having The Same - Google Patents

Abstract

By maintaining the elastic reaction force of the brush disposed between the rotor and the stator of the electric motor is provided a sag prevention brush that can supply a stable current.

The sag prevention brush electrically connects a power supply unit provided in the stator and a commutator provided in the rotor, and a base mounted on an upper surface of the stator, a contact piece contacting the commutator, and a contact piece of the base. And a body part for connecting, wherein when the contact piece sags above a set value due to plastic deformation of the brush, a part of the body part contacts the part of the stator to maintain the contact piece in contact with the commutator. It is done.

According to the brush for preventing sagging, it can minimize the deflection of the brush and prevent permanent deformation of the brush, and the elastic reaction force of the brush can be maintained even when there is external vibration or impact, and the electric motor can be prevented by preventing the energization phenomenon. The effect of being able to drive stably can be obtained.

Brush, anti sag, electric motor, rotor, stator, commutator

Description

Brush for sagging and electric motor having same {Brush For Preventing Droop And Electric Motor Having The Same}             

1 is a longitudinal sectional view of a general flat vibration motor.

2 is an exploded perspective view of a general flat vibration motor.

3 illustrates a brush provided in a general vibration motor,

   (a) is a perspective view of a jaw-shaped brush,

   (b) is a cross-sectional view of a ∠ brush,

   (c) is a perspective view of a U-band shaped brush,

   (d) is sectional drawing of a U-band shaped brush.

Figure 4 is a longitudinal sectional view of a flat vibration motor having a deflection prevention brush according to the present invention.

5 is an exploded perspective view of a flat vibration motor having a deflection prevention brush according to the present invention.

Figure 6 shows the sag prevention brush according to the invention,

   (a) is a perspective view of a drooping brush,

   (b) is sectional drawing of a brush for deflection.

7 is for explaining the deflection prevention action of the deflection prevention brush according to the present invention,

   (a) is an explanatory diagram showing the deflection of a general cantilever beam,

   (b) is an explanatory diagram for explaining the principle of deflection of the deflection prevention brush according to the present invention.

Explanation of symbols on the main parts of the drawings

110 ... rotator 115 ... commutator

120 ... Stator 122 ... Magnet

123 Power supply 130 Case

140 ... Anti-sagging brush 141 ... Base

142 First support 143 Inclination

143a ... stopper 144 ... second support

145 ... Contact piece 147 ... Body

150.Elastic means

The present invention relates to a shape of a brush for preventing sag, and more particularly, for sagging prevention to stably supply current by improving the shape of the brush disposed between the rotor and the stator of the electric motor to maintain elastic reaction force. It's about brushes.

An electric motor is a device for converting electrical energy into mechanical rotational movement. In general, a rotor having an excitation coil (winding coil) that generates magnetism by a power supply, a rotor having a magnet and rotating against the stator And a case accommodating the stator and the rotor. On the contrary, a magnet may be provided in the stator and an excitation coil may be provided in the rotor.

Such electric motors are also provided with brushes for electrically connecting the rotor and the stator.

 An example of such an electric motor is a vibration motor. The vibration motor is classified into a flat type (or coin type) and a cylindrical type (cylinder type or bar type) according to the shape of the motor.

Among them, the flat vibration motor can generate vibrations relatively simply by rotating a heavy weight body located inside the motor, and can be manufactured in a thin thickness, which is advantageous for miniaturization of mobile phone parts. Because of this, the range of use is gradually increasing.

1 is a longitudinal cross-sectional view of a general flat vibration motor, Figure 2 is an exploded perspective view of a general flat vibration motor.

As shown in FIGS. 1 and 2, the conventional flat vibration motor 1 includes a rotor assembly (hereinafter, referred to as a rotor) 10 that is a large rotating member, and a stator assembly that is a fixed member. (stator assembly) (hereinafter, referred to as a 'stator') 20 and a case 30 in which they are accommodated.

That is, as shown in FIGS. 1 and 2, the rotor 10 is an eccentric rotation structure rotatably assembled in the case 30, which is the upper substrate 11, the winding coil 12, and the weight 13. , The insulator 14 and the commutator 15.

The lower surface of the upper substrate 11 on which the pattern circuit is formed is provided with a commutator 15 having a contact surface composed of a plurality of segments spaced apart at a predetermined interval in the circumferential direction. Each segment of is in elastic contact with the top of the pair of brushes 25 provided on the stator 20.

Meanwhile, as shown in FIGS. 1 and 2, the stator 20 is a fixed structure provided on the bracket 35 assembled to block the lower portion of the case 30 which is downwardly opened, and includes a lower substrate 21, It is composed of a magnet 22, a power supply 23 and a brush (25).

The upper surface of the lower substrate 21 on which the pattern circuit is formed is provided with a pair of brushes 25, the upper ends of which are elastically supported on the commutator 15 of the stator 20, and each other end of the brushes 25 is the lower substrate. The lower end of the power supply unit 23 is electrically connected to the positive electrode terminal 23a and the negative electrode terminal 23b of the power supply unit 23 so that the lower end is fixed to the positive electrode 21 and the positive polarity and the negative electrode are different from each other.

In addition, the rotor 10 is rotatably assembled via the bearing member 32 to the shaft 31 provided perpendicular to the center of the upper surface of the bracket 35, the bearing member 32 is Is embedded in the insulator 14 of the rotor 10, the upper and lower ends of the shaft 31 is provided on the upper surface of the bracket 35 and the lower surface of the case 30 shaft support portion 31a ( 31b) respectively.

In the case of the conventional vibration motor (1), the brush 25, the upper end of which is in elastic contact with the commutator 15 to electrically connect between the power supply unit 23 and the winding coil 12 interferes with the shaft 31. They are arranged in pairs so that they do not have an arc shape.

3 is a perspective view of a conventional brush, and FIGS. 3A and 3B are respectively a perspective view and a cross-sectional view of a jaw-shaped brush, and FIGS. 3C and 3D are a perspective view and a cross-sectional view of a U-band brush, respectively.

As shown in Fig. 3, the conventional brush 25 has a slight difference in shape, but from a support piece 25a fixed to the lower substrate 21 and one end of the support piece 25a. And an inclined piece 25b extending obliquely upward, and a contact piece 25c on an arc-shaped cross section extending therefrom and contacting the commutator 15.

The conventional brush 25 has a form of a cantilever beam based on the bent portion of the support piece 25a fixed to the lower substrate 21 as a whole.

Accordingly, the brush 25 is an external force transmitted directly downward by the rotor 10 is rotated in one direction in the state in which the contact piece 25c is in elastic contact with the commutator 15. It is functioning so that the contact of the contact piece 25c and the commutator 15 may be hold | maintained.

However, when the brush 25 is used for a long time or a sudden change in temperature or humidity occurs, the impact force generated while passing between the gaps of the commutator 15 and the external force pressed down directly from the rotor 10 are transmitted. As a result, the inclined piece 25b sag downward or the permanent sag (plastic deformation) in which the lower sag deformation is maintained based on the bent portion 25d.

When the phenomenon in which the brush 25 sags downward in this way, the contact piece 25c of the brush 25 is spaced apart from the commutator 15, and thus it is impossible to maintain a stable contact state without contacting the power supply unit ( 23, a non-electrical phenomenon in which the current supplied through the brush 25 and the commutator 15 is not transmitted to the winding coil 12 is generated, which causes the rotor 10 to not rotate and the motor is driven. You will not be able to keep it stable.

In order to solve the conventional problems as described above, the present invention minimizes the deflection of the brush, prevents the permanent deformation to prevent the non-electrical phenomena due to contactless, and the sag prevention brush that can maintain the motor drive stable and An object of the present invention is to provide an electric motor having the same.

In one aspect for achieving the above object, a brush disposed between the rotor and the stator of the electric motor to electrically connect the power supply unit provided in the stator and the commutator provided in the rotor, the brush is A base mounted on an upper surface of the stator, a contact piece in contact with the commutator, and a body part connecting the base and the contact piece, and when the contact piece sags above a set value by plastic deformation of the brush, And a portion of the body portion in contact with a portion of the stator to maintain the contact piece in contact with the commutator.

Preferably, the body portion is bent upwardly extending from the base, the first support piece, the inclined piece is bent downwardly extending from the first support piece, and is bent upwardly extending from the inclined piece and the contact And a second support piece connected to the piece, wherein a bent portion between the inclined piece and the second support piece contacts a portion of the stator.

In this case, the contact piece may be formed of a plurality of branches branched to at least two or more, and may be provided with an embossed portion on the upper surface to make point contact with the lower surface of the commutator.

In another aspect, the present invention, the electric motor provided with a brush disposed between the rotor and the stator to electrically connect the power supply provided in the stator and the commutator provided in the rotor, wherein the brush is the brush; A base mounted on the upper surface of the stator, a contact piece in contact with the commutator, and a body portion connecting the base and the contact piece, wherein the body is sag over a set value by plastic deformation of the brush. A part of the part is in contact with a part of the stator to provide an electric motor having an anti-sag brush, characterized in that the contact piece to keep in contact with the commutator.

Preferably, the body portion is bent upwardly extending from the base, the first support piece, the inclined piece is bent downwardly extending from the first support piece, and is bent upwardly extending from the inclined piece and the contact And a second support piece connected to the piece, wherein a bent portion between the inclined piece and the second support piece contacts a portion of the stator.

In this case, the stator may be provided with an elastic means for providing an elastic force in contact with the body portion.

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

4 and 5 are a longitudinal sectional view and an exploded perspective view of a flat vibration motor having a deflection brush according to the present invention, respectively, Figures 6a and 6b are a perspective view and a cross-sectional view of the deflection prevention brush according to the present invention.

The sag prevention brush 140 according to the present invention is applicable to an electric motor having a brush electrically connecting the rotor and the stator, but for convenience of description, the flat vibration motor shown in FIGS. 4 and 5 will be described. do.

4 and 5, the deflection prevention brush 140 according to the present invention is disposed between the rotor 110 and the stator 120 of the vibration motor 100 to generate a vibration when the power is applied to the The upper end thereof is in contact with the commutator 115 to apply a current to the winding coil 112 of the rotor 110. In this case, the brush 140 is formed in a pair and is electrically connected to the positive electrode terminal 123a and the negative electrode terminal 123b of the power supply unit 123, respectively.

As shown in FIGS. 4 and 5, the vibration motor 100 employing the brush 140 is a rotor 110 as a rotating structure, a stator 120 as a fixed structure, and a case 130 in which they are accommodated. It is composed.

The rotor 110 is a rotator provided to be eccentrically rotatable through the shaft 131 and the bearing member 132 of the case 130, and the lower surface of the upper substrate 111 is a pattern printed with various circuits It has a commutator 115 consisting of a plurality of segments (segments) divided into a plurality at intervals in the circumferential direction at the center of the center, the contact surface is exposed to the lower side, in addition to the winding coil 112, high specific weight body 113, An insulator 114 and the like.

In addition, the stator 120 is provided with a lower substrate 121 on the upper surface of the bracket 135 is assembled to the open lower portion of the case 130, the winding coil 112 of the rotor 110 and Near the outer circumference of the upper surface of the bracket 135 corresponding to each other is provided with a magnet 122 in which the N pole and the S pole are alternately magnetized in the circumferential direction.

In addition, one side of the lower substrate 121 is electrically connected to an external power supply lead wire (not shown) to supply positive and negative polarities (+) and negative electrodes (−), respectively, to the brush 140. A power supply unit 123 having cathode terminals 123a and 123b is provided.

On the other hand, the deflection prevention brush 140 is in contact with the top of the commutator 115 to energize the current to the winding coil 112 side of the rotor 110, a pair of left and right as shown in Figs. The lower end is fixed to the vicinity of the opening formed through the central portion of the lower substrate 121 is configured.

The brush 140 extends from the positive electrode and the negative electrode terminals 123a and 123b such that positive and negative polarities having different polarities are supplied from the positive electrode terminal 123a and the negative electrode terminal 123b of the power supply unit 123, respectively. It is electrically connected to the conductive connection patterns 126a and 126b printed on the upper surface of the lower substrate 121.

With reference to Figure 6 looks at in more detail with respect to the sag prevention brush 140 according to the present invention.

The brush 140 has a base 141 mounted on the upper surface of the stator 120, a contact piece 145 contacting the commutator 115, and a body connecting the base 141 and the contact piece 145. A part 147 is provided, and when the contact piece 145 sags above a set value due to plastic deformation of the brush 140, a part of the body part 147 is formed by a part of the stator 120. Contact so that the contact piece 145 is in contact with the commutator 115.

Here, the 'set value' refers to the amount of deflection of the contact piece 145 in which contact between the contact piece 145 and the commutator 115 can be maintained by the elastic reaction force of the brush 140.

In particular, when the body portion 147 of the brush 140 is in contact with the stator as described below, the effect of improving the rigidity of the brush 140 can be obtained, the deflection of the contact piece 145 of the brush 140 There is an advantage that can be minimized.

Preferably, the body portion 147 of the brush 140, as shown in Figure 6, the first support piece 142 is bent upwardly extending from the base 141 and the first support piece An inclined piece 143 bent downwardly from 142 to extend, and a second support piece bent upwardly from the inclined piece 143 and connected to the contact piece; And a stopper 143a, which is a bent portion between the second support piece 144 and a part of the stator 120, come into contact with each other.

At this time, the stopper 143a needs to be spaced apart from the stopper 143a so that a short does not occur when the stopper 143a contacts the circuit part of the stator 120.

In addition, the contact piece 145 is preferably formed of a plurality of branches branched to at least two to make contact with the commutator 115, the embossing on the upper surface to point contact with the lower surface of the commutator 115 You may be provided with a part.

On the other hand, as shown in Figure 6b, the stator 145 may be provided with an elastic means 150 for providing an elastic force to the stopper (143a) when in contact with the body portion 147, in particular the stopper (143a). The elastic means 150 serves to adjust the height from the bottom surface of the stator 120 to the stopper 143a and to provide the elastic repulsive force when the stopper 143a contacts. ) And the commutator 115 to facilitate electrical contact.

With reference to Figures 4, 6b and 7 looks at the action of the anti-sag brush according to the present invention.

Figure 7a is an explanatory view showing the deflection of the cantilever in general, Figure 7b is an explanatory view for explaining the deflection prevention principle of the deflection prevention brush according to the present invention.

In the case of assembling the electric motor, the brush 140 is assembled in the pressed state (preloaded state) by the rotor 110, and the brush 140 must maintain a constant tension due to elastic force. The electrical connection function between the 120 and the rotor 110 may be smoothly performed.

However, when plastic deformation occurs in the brush 140 due to the use of a motor or external impact or vibration, the elastic reaction force of the brush 140 is weakened, and thus the contact piece 145 of the brush and Since the electrical connection of the commutator 115 is not made, a non-conduction phenomenon may occur.

When the deflection of the contact piece 145 occurs above the set value, the stopper 143a, which is a part of the body 147, comes into contact with a part of the stator 120. In this case, the length of the cantilever beam is shortened. The effect occurs and the stiffness of the brush 140 itself is improved, so that the elastic reaction force of the brush can be further increased.

This can be seen from the following equation.

As shown in Fig. 7a, when load (pressing force) P is applied to the end of a uniform cross-section cantilever beam of length L, the deflection amount δ _max of the uniform cross-section beam is E, Young's Modulus is E, and the moment of inertia of the cross section is I Equation 1 is expressed as

[Equation 1]

Therefore, since the value of the material constant E and the moment of inertia I of the cross section are constant, when the amount of deflection δ _max is constant from Figs. 7A and 1, the following correlation can be obtained.

[Equation 2]

In other words, the force P (actual force P required until the deflection amount becomes δ _max) which acts to generate a constant deflection amount δ _max is inversely proportional to the cube of the length L of the cantilever beam. It can be seen that a large force must be applied to obtain _max .

On the other hand, when the load P in the vertical direction acts on the contact piece 145 as shown in FIG. 7B, the amount of deflection of the contact piece 145 of the brush 140 is determined by the component force P ₁ of the load P.

Initially, when a load is applied to the contact piece 145 from the commutator 115 provided in the rotor 110, the amount of deflection of the contact piece 145 becomes P ₁ L ₁ / EI according to equation (1). Here, L ₁ is the distance from the first bent portion 141a to the action point of the load as shown in FIG. 7B.

However, when plastic deformation occurs in the contact piece 145 or when the stopper 143a comes into contact with a part of the stator 120 due to external vibration or shock, the first support piece 142 and the inclined piece 143 ) Part acts as a fixed end, so the deflection amount of the contact piece 145 becomes P ₁ L ₂ / EI by Equation 1. Here, L ₂ is the distance from the stopper 143a to the action point of the load as shown in FIG. 7B.

At this time, comparing the force applied when the same deflection occurs using the equation 2, that is, the elastic reaction force of the brush 140, L ₁ is larger than L ₂ can be obtained the same as the following equation 3.

[Equation 3]

That is, when a part of the body portion 147 of the brush 140 is in contact with a part of the stator 120, the length of the cantilever can be shortened to obtain an effect of increasing rigidity. It can withstand and provides greater elastic reaction force so that the electrical contact between the commutator 115 and the contact piece 145 is stably maintained.

Therefore, it is possible to drive the motor more stably by preventing the non-energization phenomenon, there is an advantage that the elastic reaction force of the brush 140 can be maintained even from external vibration or impact.

According to the present invention as described above, when the contact piece of the brush sags more than the set value due to the plastic deformation of the brush, the part of the body to contact the stator to prevent the additional sagging of the brush, and minimize the lower sagging of the brush It also has the effect of preventing permanent deformation of the brush.

In addition, even if a large load is applied to the brush due to external vibration or impact, there is an advantageous effect that the elastic reaction force of the brush can be maintained by increasing the rigidity by contacting a part of the body of the brush with the stator.

Furthermore, by preventing the non-energization phenomenon caused by the non-contact of the contact piece of the brush and the commutator, there is an advantageous effect that the electric motor can be driven more stably by suppressing a defect such as a decrease in the rotational speed of the motor.

While the invention has been shown and described with respect to particular embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I want to make it clear.

In particular, although the present invention has been described mainly with respect to a flat vibration motor, it is intended to be clear that it can be widely applied to a general electric motor having a brush.

Claims (7)

In the brush disposed between the rotor and the stator of the electric motor to electrically connect the power supply unit provided in the stator and the commutator provided in the rotor, The brush has a base mounted on the upper surface of the stator, a contact piece in contact with the commutator, a body portion connecting the base and the contact piece, And a portion of the body portion is in contact with a portion of the stator when the contact piece sags above a set value due to plastic deformation of the brush, so that the contact piece maintains contact with the commutator. The method of claim 1, The body portion is bent upwardly extending from the base, the first support piece, the inclined piece is bent downwardly extending from the first support piece, is bent upwardly extending from the inclined piece and connected to the contact piece A second support piece, And the bent portion between the inclined piece and the second support piece is in contact with a portion of the stator. The method according to claim 1 or 2, The contact piece is formed of a plurality of branches branched at least two or more sag prevention brush. The method according to claim 1 or 2, The contact piece is provided with an embossing portion on the upper surface to be in point contact with the lower surface of the commutator. In the electric motor having a brush disposed between the rotor and the stator to electrically connect the power supply unit provided in the stator and the commutator provided in the rotor, The brush has a base, the brush is mounted on the upper surface of the stator, a contact piece in contact with the commutator, a body portion connecting the base and the contact piece, When the contact piece is drooped above a set value by plastic deformation of the brush, a part of the body portion is in contact with a part of the stator, so that the contact piece maintains contact with the commutator. Electric motor. The method of claim 5, The body portion is bent upwardly extending from the base, the first support piece, the inclined piece is bent downwardly extending from the first support piece, is bent upwardly extending from the inclined piece and connected to the contact piece With a second support piece, And a bent portion between the inclined piece and the second support piece is in contact with a portion of the stator. The method according to claim 5 or 6, The stator is provided with an anti-sag brush, characterized in that it comprises an elastic means for providing an elastic force to the body portion in contact with the body portion.

Images