CN113972808B

CN113972808B - Linear vibration motor

Info

Publication number: CN113972808B
Application number: CN202111256836.4A
Authority: CN
Inventors: 高俊平; 牟雷; 孙野
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2021-10-27
Filing date: 2021-10-27
Publication date: 2023-05-09
Anticipated expiration: 2041-10-27
Also published as: CN113972808A

Abstract

The invention belongs to the technical field of electronic products, and particularly relates to a linear vibration motor, which comprises a driving assembly and a magnetic assembly, wherein the driving assembly comprises a plurality of annular coils which are distributed at intervals along the vibration direction, each annular coil is obliquely distributed along the vibration direction, and two driving surfaces of the same annular coil are suitable for being mutually staggered; the magnetic assembly comprises a plurality of permanent magnets which are arranged on the inner side of the annular coil and are sequentially distributed along the vibration direction, the magnetizing directions of two adjacent permanent magnets are opposite, and two magnetic poles of each permanent magnet respectively correspond to the driving surfaces of two adjacent annular coils; either the driving component or the magnetic component is a stator, and the other is a rotor. Through the structure, the attenuation speed of the driving force between the driving component and the magnetic component along with the increase of the amplitude is reduced, the electromagnetic efficiency of the motor is improved, and the power consumption is reduced.

Description

Linear vibration motor

Technical Field

The invention belongs to the technical field of electronic products, and particularly relates to a linear vibration motor.

Background

With the development of communication technology, portable electronic products, such as mobile phones, palm game players or palm multimedia entertainment devices, are entering people's lives. In these portable electronic products, a micro vibration motor is generally used for system feedback, such as call prompt of a mobile phone, vibration feedback of a game machine, and the like.

The conventional micro-vibration motor generally includes a housing forming a vibration space, a vibrator (generally including a weight and a permanent magnet) for linearly and reciprocally vibrating in the vibration space, and a stator cooperating with the vibrator.

The vibration principle of the miniature vibration motor is as follows: the permanent magnet of the vibrator generates a magnetic field, the stator coil positioned in the magnetic field is stressed, and the vibrator moves in a certain direction under the drive of the reaction force because of the relative fixation of the stator, the current direction of the stator coil is changed, and the vibrator moves in the opposite direction, so that vibration is generated.

However, the above-described conventional structure of the micro vibration motor has the following drawbacks:

a flat coil or a regular cubic coil is generally adopted as a driving unit, but the generated driving force is too fast in attenuation rate along with the displacement change of the vibrator, so that the amplitude of the vibrator is smaller;

the elastic support piece is easy to generate stress concentration in the vibration process, so that plastic deformation and polarization are caused, and the experience and the use problem of a user are affected.

Disclosure of Invention

The invention aims to provide a linear vibration motor so as to solve the problem that the attenuation rate of driving force along with the displacement change of a vibrator is too fast in the prior art.

The present invention provides a linear vibration motor, comprising: the driving assembly comprises a plurality of annular coils which are arranged at intervals along the vibration direction, each annular coil is obliquely arranged along the vibration direction, and the driving assembly is suitable for staggering two driving surfaces of the same annular coil; the magnetic assembly comprises a plurality of permanent magnets which are arranged on the inner side of the annular coil and are sequentially distributed along the vibration direction, the magnetizing directions of two adjacent permanent magnets are opposite, and two magnetic poles of each permanent magnet respectively correspond to the driving surfaces of two adjacent annular coils; either the driving component or the magnetic component is a stator, and the other is a rotor.

The linear vibration motor as described above, further preferably, further includes a housing and an elastic member; the two elastic pieces are respectively positioned at two ends of the magnetic assembly, one end of each elastic piece is connected with the magnetic assembly, and the other end of each elastic piece is connected with the inner wall of the shell and is suitable for suspending the magnetic assembly in the shell; the driving component is also fixed in the shell.

As described above, it is further preferable that the elastic member includes two connecting arms and three elastic cantilevers connected in an S-shape, an arc-shaped notch is provided on the connecting arm, and two sides of the arc-shaped notch are connected to the two elastic cantilevers, respectively.

The linear vibration motor as described above, further preferably, the driving assembly further includes a coil bracket provided between the magnetic assembly and the housing, and an inclined guide groove is provided on an outer surface of the coil bracket, the guide groove being adapted to be wound with the annular coil.

In the linear vibration motor, it is further preferable that the housing includes an upper housing and a support base plate which are relatively fastened, and both end portions of the support base plate are each provided with a bent portion adapted to be connected to the elastic member.

As described above, it is further preferable that the coil bracket further has a positioning boss on a bottom surface thereof, and the support base plate has a positioning through hole, and the positioning boss is adapted to the positioning through hole.

In the linear vibration motor described above, it is further preferable that the upper case is provided with a plurality of first detection through holes, the coil holder is provided with a plurality of second detection through holes, and positions of the first detection through holes and the second detection through holes correspond to each other.

The linear vibration motor as described above further preferably further includes a flexible circuit board provided in the housing and electrically connected to the plurality of loop coils.

The linear vibration motor as described above, further preferably, the magnetic assembly further includes a weight member glued to both ends of the permanent magnet, adapted to be connected with the elastic member.

As described above, it is further preferable that the number of the permanent magnets is at least one less than the number of the ring coils.

The invention discloses a linear vibration motor which mainly comprises a driving assembly and a magnetic assembly, wherein the driving assembly comprises a plurality of annular coils which are arranged at intervals along the vibration direction, each annular coil is obliquely arranged along the vibration direction, and two driving surfaces of the same annular coil are suitable for being mutually staggered; the magnetic assembly comprises a plurality of permanent magnets which are arranged on the inner side of the annular coil and are sequentially distributed along the vibration direction, the magnetizing directions of two adjacent permanent magnets are opposite, and two magnetic poles of each permanent magnet respectively correspond to the driving surfaces of two adjacent annular coils; either the driving component or the magnetic component is a stator, and the other is a rotor. So that the length of the toroidal coil in the vibration direction increases, that is, the distribution area of the conductor for cutting the magnetic induction wire in the vibration direction increases, and thus the area range in which the driving force can be provided increases accordingly. Meanwhile, compared with the horizontal relative magnetization of the permanent magnet, in the structure, the magnetization direction of the permanent magnet enables the magnetic field distribution to be more concentrated, the area of the magnetic field area is increased, and along with the vibration of the permanent magnet, the position change between the magnetic field and the annular coil is relatively small, namely the number change of coils for cutting the magnetic induction lines to provide driving force is also relatively small. The two are combined, so that the attenuation speed of the driving force along with the increase of the amplitude is reduced, the electromagnetic efficiency of the motor is improved, and the power consumption is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an exploded construction of a linear vibration motor of the present invention;

FIG. 2 is a schematic cross-sectional view of the linear vibration motor of FIG. 1;

FIG. 3 is a schematic view of an elastomer structure in a linear vibration motor;

FIG. 4 is a front view of FIG. 3;

FIG. 5 is a schematic view of another construction of an elastomer of a linear vibration motor;

FIG. 6 is a schematic view of the housing of FIG. 1;

fig. 7 is a schematic view of the coil support of fig. 1.

Reference numerals illustrate:

1-a toroidal coil; 2-permanent magnets; 3-coil support, 31-positioning boss, 32-guiding groove, 33-second detection through hole; 4-balancing weight; 5-elastic piece, 51-connecting arm, 52-elastic cantilever, 53-connecting surface; 6-upper shell, 61-first detection through hole; 7-supporting bottom plates, 71-positioning through holes, 72-bending parts and 73-third detection through holes; 8-flexible circuit board.

Detailed Description

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in the present invention will be understood in detail by those skilled in the art.

In order to solve the problem that the driving force decays too fast along with the change of the vibrator displacement due to the adoption of a flat coil or a regular cubic coil in the conventional driving unit, the arrangement mode of the annular coil 1 and the permanent magnet 2 is optimized. Specifically, the linear vibration motor provided by the embodiment comprises a driving assembly and a magnetic assembly, wherein the driving assembly comprises a plurality of annular coils 1 which are arranged at intervals along the vibration direction, each annular coil 1 is obliquely arranged along the vibration direction, two driving surfaces of the same annular coil 1 are suitable for being staggered, and the energizing directions of two adjacent annular coils 1 are opposite; the magnetic assembly comprises a plurality of permanent magnets 2 which are arranged on the inner side of the annular coil 1 and sequentially distributed along the vibration direction, the magnetizing directions of two adjacent permanent magnets 2 are opposite, and two magnetic poles of each permanent magnet 2 respectively correspond to the driving surfaces of the two adjacent annular coils 1. In practical application, according to design requirement, any one of the driving component or the magnetic component can be fixedly arranged to serve as a stator, the other one is relatively movably arranged to serve as a vibrator, and the stator and the vibrator are relatively displaced under the driving of acting force and reacting force. In this embodiment, as shown in fig. 2, it is preferable that the driving unit is used as a stator, the toroidal coil 1 is fixedly installed, the driving surfaces are an upper surface and a lower surface, respectively, and the magnetic unit is used as a vibrator, so that the magnetizing direction of the permanent magnet 2 is up and down.

By virtue of the above-described structure, the length of the toroidal coil 1 in the vibration direction is increased, that is, the distribution area of the conductors for cutting the magnetic induction lines in the vibration direction is increased, and thus the area range in which the driving force can be provided in the driving direction is also increased accordingly. Meanwhile, compared with the horizontal relative magnetization of the permanent magnet 2, the upper and lower magnetization of the permanent magnet 2 enables the magnetic field in the magnetic assembly to be distributed on the upper and lower surfaces of the permanent magnet 2 in a concentrated manner, even if the area of the magnetic field area is increased, the position change between the magnetic field and the annular coil 1 is relatively small in the vibration process of the permanent magnet 2, namely the change of the magnetic field for providing the magnetic induction line is also relatively small. The two are combined, so that the attenuation speed of the driving force between the annular coil 1 and the permanent magnet 2 along with the increase of the amplitude is reduced, the electromagnetic efficiency of the motor is improved, and the power consumption is reduced.

Fig. 1 and 2 show an exploded structural view and a sectional structural view of a linear vibration motor of the present embodiment, respectively, and as shown in fig. 1 and 2, the linear vibration motor of the present embodiment mainly includes a housing constituting a package structure, a driving assembly, a magnetic assembly, an elastic member 5, and a flexible circuit board 8 disposed inside the housing.

The driving assembly comprises a plurality of annular coils 1 and a coil bracket 3 for winding the plurality of annular coils 1, specifically, as shown in fig. 7, the coil bracket 3 is of a cuboid shell structure with two open ends, the periphery of the coil bracket is provided with guide grooves 32 which are obliquely arranged, and the number of the guide grooves 32 is the same as that of the annular coils 1 so as to be suitable for winding, guiding and reversing the plurality of annular coils 1. The plurality of toroidal coils 1 may be wound at one time, or may be wound in other ways such as series-parallel connection. A positioning boss 31 for auxiliary positioning is arranged on the bottom surface of the coil bracket 3 so as to be fixedly connected with the shell; the coil bracket 3 is also provided with a plurality of second detection through holes 33 and magnetic liquid injection through holes, the second detection through holes 33 are positioned at the side edges and used for detection, and the magnetic liquid injection through holes are positioned at the upper surface and the lower surface and used for injecting magnetic liquid.

The magnetic assembly comprises a plurality of permanent magnets 2 and a balancing weight 4, wherein the number of the permanent magnets 2 is at least one less than that of the annular coils 1, so that when the annular coils 1 are not electrified, the magnetic poles of the plurality of permanent magnets 2 which are sequentially arranged are provided with corresponding driving surfaces. In practical application, the number of the permanent magnets 2 and the annular coils 1 can be set arbitrarily according to the amplitude requirement, and in this embodiment, the specific description is given by taking 2

permanent magnets

2 and 3 annular coils 1 as examples. The balancing weight 4 is arranged at two ends of the permanent magnet 2, wherein the balancing weight 4 and the permanent magnet 2 are connected in various modes, and the balancing weight 4 is mainly connected in a gluing mode in the embodiment. The balancing weight 4 can be made of tungsten steel blocks or nickel tungsten alloy and other high-density metal materials so as to increase vibration force and make the vibration of the electronic product stronger.

As shown in fig. 6, the outer shell is in a cuboid shape and comprises an upper shell 6 and a supporting bottom plate 7 which can be correspondingly buckled, wherein the upper shell 6 is a cuboid shell with one surface open, and a first detection through hole 61 is formed in the upper shell; the support base plate 7 is a flat plate, and is provided with a positioning through hole 71 and a bent portion 72. Specifically, the number of the first detecting through holes 61 is plural, and the first detecting through holes are also distributed at the side edges of the upper case 6, and the positions of the first detecting through holes correspond to the positions of the second detecting through holes 33. The number of the positioning through holes 71 is two, and the positions of the positioning through holes correspond to the positions of the two positioning bosses 31 on the coil bracket 3, and the positioning through holes are suitable for being matched and installed with the positioning bosses 31 on the coil bracket 3; the two bending parts 72 are vertically arranged at two ends of the supporting bottom plate 7 and are suitable for being connected with the elastic piece 5 for buffering the vibration of the magnetic assembly so as to prevent the magnetic assembly from impacting the end part of the upper shell 6 during the vibration. In addition, a plurality of third detection through holes 73 are formed in the supporting base plate 7, and the positions of the third detection through holes 73 correspond to the positions of the second detection through holes 33, so that the inside condition of the housing can be detected.

As shown in fig. 2, 3, 4 and 5, the elastic members 5 are elastic sheets, and the number of the elastic members is two, and the elastic members are respectively arranged at two ends of the magnetic assembly and are suitable for connecting the magnetic assembly and the housing. The shell fragment is spacing fixed between magnetic component and shell, and magnetic component can extrude the shell fragment of one end at the in-process of vibration, and the shell fragment self that receives the extrusion warp in order to prevent that magnetic component from colliding with the shell at the in-process of vibration, also can provide the ascending elastic restoring force of reverse direction for magnetic component's vibration simultaneously.

Further, the elastic sheet comprises two connecting arms 51 and three elastic cantilevers 52 which are connected in an S shape, an arc-shaped notch is arranged on the connecting arm 51, and two sides of the arc-shaped notch are respectively connected with the two elastic cantilevers 52; the free ends of the two elastic cantilevers 52 are also provided with a connecting surface 53, and the two connecting surfaces 53 are respectively used for being connected with the shell and the magnetic assembly, specifically, the two connecting surfaces 53 are respectively connected with the bending part 72 and the balancing weight 4. As shown in fig. 3 and 4, the connecting arms 51 may be preferably disposed at both sides of the length direction of the elastic arm, limited by the height dimension of the housing, to more effectively use the height space dimension, increase the excessive connecting area, and reduce the stress concentration during the vibration deformation. Further, as shown in fig. 5, if there is redundancy in the height space dimension, the connection arms 51 may be provided on both sides in the width direction of the elastic arms. In the above structure, the arc notch in the spring plate makes the connecting arm 51 be an excessive connecting arm 51 with a large curvature, thereby reducing the local stress of the spring plate and improving the fatigue life. In addition, the vibration frequency and the mode of the linear vibration motor can be adjusted by adjusting the width, the shape and the plate thickness of the elastic arm or the connecting arm 51 of the elastic sheet and the shape of the cutting notch.

A flexible circuit board 8 is provided in the housing for mounting the plurality of loop coils 1 into the electronic device system.

In the above structure, the permanent magnet 2 is magnetized vertically, magnetic lines of force generated on the upper and lower surfaces of the permanent magnet vertically pass through the annular coil 1 respectively, when the linear motor works, sinusoidal current is fed into the annular coil 1, the period of the sinusoidal current is twice the time for the permanent magnet 2 to move from the current position to the position of the adjacent permanent magnet 2, and meanwhile, the sinusoidal current in the adjacent annular coil 1 is adjusted, so that the currents of the adjacent annular coils 1 are identical in size and opposite in direction. According to the left hand rule for judging the stress direction of the energized conductor in the magnetic field, it can be known that when the energized conductor is energized, the stress directions of the coils at the two ends of the plurality of permanent magnets 2 are the same and parallel to the vibration direction, and because the annular coil 1 is fixed, the permanent magnets 2 are subjected to opposite acting forces based on the relation between the acting forces and the reaction forces, and the balancing weights 4 are driven to move in a translational mode in opposite directions. When the permanent magnet 2 moves to the position of the adjacent permanent magnet 2, the direction of the current in the toroidal coil 1 is completely reversed, the direction of the reaction force applied at the current position is still consistent with the previous one, and the movement is continued at the reaction force until the limit position. Similarly, the current direction in the annular coil 1 is changed, so that the corresponding relation between the annular coil and the magnetic pole of the permanent magnet 2 is changed, and the magnetic pole is driven by the driving force with the same direction and opposite direction based on the acting force and the reacting force, and the balancing weight 4 is driven to move in the opposite direction. The motion is operated alternately to drive the micro vibration motor to vibrate.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A linear vibration motor, comprising:

the driving assembly comprises a plurality of annular coils which are arranged in a row at intervals along the vibration direction and form a central channel, and each annular coil is obliquely arranged along the vibration direction and is suitable for staggering two driving surfaces of the same annular coil;

the magnetic assembly comprises a plurality of permanent magnets which are arranged in the central channel of the annular coil and are sequentially distributed along the vibration direction, the magnetizing directions of two adjacent permanent magnets are opposite, and two magnetic poles of each permanent magnet respectively correspond to the driving surfaces of two adjacent annular coils;

either the driving component or the magnetic component is a stator, and the other is a rotor.

2. The linear vibration motor of claim 1, further comprising a housing and an elastic member; the two elastic pieces are respectively positioned at two ends of the magnetic assembly, one end of each elastic piece is connected with the magnetic assembly, and the other end of each elastic piece is connected with the inner wall of the shell and is suitable for suspending the magnetic assembly in the shell; the driving component is also fixed in the shell.

3. The linear vibration motor according to claim 2, wherein the elastic member comprises two connecting arms and three elastic cantilevers connected in an S-shape, arc-shaped notches are provided on the connecting arms, and both sides of the arc-shaped notches are respectively connected with the two elastic cantilevers.

4. The linear vibration motor of claim 2, wherein the drive assembly further comprises a coil support disposed between the magnet assembly and the housing, and wherein an inclined guide groove is provided in an outer profile of the coil support, the guide groove being adapted to be wound with the annular coil.

5. The linear vibration motor of claim 4, wherein the housing comprises an upper housing and a supporting base plate which are relatively buckled, and both end portions of the supporting base plate are respectively provided with a bending portion, and the bending portions are adapted to be connected with the elastic member.

6. The linear vibration motor of claim 5, wherein a positioning boss is further provided on a bottom surface of the coil support, and a positioning through hole is provided on the support base plate, and the positioning boss is adapted to the positioning through hole.

7. The linear vibration motor of claim 5, wherein the upper case is provided with a plurality of first detection through holes, the coil support is provided with a plurality of second detection through holes, and positions of the first detection through holes and the second detection through holes correspond to each other.

8. The linear vibration motor of claim 2, further comprising a flexible circuit board disposed within the housing and electrically connected to the plurality of annular coils.

9. The linear vibration motor of claim 2, wherein the magnetic assembly further comprises a weight block glued to both ends of the permanent magnet, adapted to be connected with the elastic member.

10. The linear vibration motor of claim 1, wherein the number of permanent magnets is at least one less than the number of toroidal coils.