CN106655696B

CN106655696B - Linear vibration motor

Info

Publication number: CN106655696B
Application number: CN201611083207.5A
Authority: CN
Inventors: 祖峰磊; 秦小森
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2016-11-30
Filing date: 2016-11-30
Publication date: 2020-05-29
Anticipated expiration: 2036-11-30
Also published as: CN106655696A

Abstract

The invention discloses a linear vibration motor, which comprises a shell (1) and a driving device accommodated in the shell (1), wherein the shell (1) is provided with a magnetic conduction part (111), and the driving device comprises a coil (2), a Halbach array and a balance magnet assembly (43); the plane where the coil (2) is located is parallel to the vibration direction, the coil (2) and the magnetic conduction part (111) are respectively arranged on two sides of the Halbach array, and the coil (2) is located on one side of the Halbach array in a strong magnetic field; the balance magnet assembly (43) is fixed relative to the Halbach array, the balance magnet assembly (43) is arranged close to the magnetic conduction part (111) relative to the coil (2), the balance magnet assembly (43) comprises at least one first magnet (431), and all the first magnets (431) have the same magnetizing direction and are perpendicular to the plane where the coil (2) is located.

Description

Linear vibration motor

Technical Field

The present invention relates to the field of motor technology, and more particularly, to a linear vibration motor.

Background

With the development of communication technology, portable electronic devices, such as mobile phones, tablet computers, multimedia entertainment devices, etc., have become essential for people's life. In these electronic devices, a miniature linear vibration motor is generally used for feedback of the system, such as vibration feedback of incoming call prompt of a mobile phone.

The linear vibration motor generally includes a vibrator and a stator, the vibrator further includes a mass block, a magnet assembly, a spring plate, and the like, the stator further includes a FPCB, a coil, and the like, wherein the coil and the FPCB are fixedly connected to a housing of the linear vibration motor, the mass block and the magnet assembly are fixedly connected together, the spring plate is connected between the mass block and the housing, and the coil is located within a magnetic field range generated by the magnet assembly. Therefore, after the coil is electrified, the coil can be acted by ampere force, and the coil is fixedly connected to the shell, so that the vibrator can regularly vibrate in a reciprocating mode under the driving of the reaction force of the ampere force, and the mass block is large in mass, so that the effect of vibration of the whole linear vibration motor can be obtained.

It can be seen that the reaction force of the above-mentioned ampere force is the only force for driving the vibrator to vibrate, but is limited by the space volume of the coil, the number of turns of the coil and the effective length of the coil, and the ampere force is usually small, which is an important reason for the long response time of the existing motor, so that it is very necessary to provide a motor structure capable of increasing the driving force provided to the vibrator.

Disclosure of Invention

An object of an embodiment of the present invention is to provide a new technical solution of a linear vibration motor to increase a driving force that can be provided to a vibrator.

According to a first aspect of the present invention, there is provided a linear vibration motor comprising a housing and a drive device housed in the housing, the housing having a magnetically permeable portion, the drive device comprising a coil, a halbach array and a balanced magnet assembly; the plane where the coil is located is parallel to the vibration direction, the coil and the magnetic conduction part are arranged on two sides of the Halbach array, and the coil is located on one side of a strong magnetic field of the Halbach array; the balance magnet assembly is fixed relative to the Halbach array, is arranged relative to the coil and is adjacent to the magnetic conduction part, and comprises at least one first magnet, and all the first magnets have the same magnetizing direction and are perpendicular to the plane where the coil is located.

Optionally, the halbach array has three magnets arranged in the vibration direction, which are two radial magnets and one parallel magnet, wherein the two radial magnets have opposite magnetizing directions and are perpendicular to the plane where the coil is located, one radial magnet corresponds to the first edge of the coil, the other radial magnet corresponds to the second edge of the coil, and the magnetizing directions of the parallel magnets are parallel to the vibration direction.

Optionally, the first side portion and the second side portion are perpendicular to the vibration direction, and the driving device is symmetrical about a middle cross section of the coil perpendicular to the vibration direction.

Optionally, the driving device further includes an iron core, the iron core and the coil form an electromagnet, and the iron core includes a portion located in a central hole of the coil.

Optionally, the halbach array has parallel magnets with their magnetizing directions parallel to the vibration direction, and at least part of the first magnets of the balance magnet assembly are disposed on surfaces of the parallel magnets facing the magnetically conductive portion.

Optionally, the balance magnet assembly further includes at least one second magnet, and a magnetizing direction of the second magnet is parallel to the vibration direction.

Optionally, the balanced magnet assembly includes at least two second magnets, and all the second magnets form at least one pair of opposing magnets, and the two second magnets of each pair of opposing magnets are arranged side by side in the vibration direction and have opposite magnetizing directions.

Optionally, the housing further has another magnetic conductive portion, and the another magnetic conductive portion and the coil are located on the same side of the halbach array.

Optionally, the linear vibration motor includes two or more driving devices, and the two or more driving devices are sequentially arranged in the vibration direction.

Optionally, the halbach arrays of two adjacent driving devices share one radial magnet, wherein the radial magnet is a magnet whose magnetizing direction is perpendicular to the plane where the coils are located.

The present invention has an advantageous effect in that the linear vibration motor driving apparatus according to the present invention uses the halbach array to interact with the coil, and the halbach array can generate a strong magnetic field on one side with as few magnets as possible, so that when the coil is disposed on the side of the generated strong magnetic field, the driving force applied to the vibrator can be effectively increased. However, also due to the action of the strong magnetic field, the coil and other electric and magnetic devices may apply a downward attraction force to the halbach array and further to the whole vibrator to interfere the movement track of the vibrator in the vibration direction, so that the designed resonance frequency deviates from the actual situation, and meanwhile, the elastic sheet of the linear vibration motor is greatly damaged.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic structural view of an embodiment of a linear vibration motor according to the present invention;

fig. 2 is a schematic structural view of another embodiment of a linear vibration motor according to the present invention;

fig. 3 is a schematic structural view of a third embodiment of a linear vibration motor according to the present invention;

fig. 4 is a schematic structural view of a fourth embodiment of a linear vibration motor according to the present invention;

fig. 5 is a schematic structural view of a fifth embodiment of a linear vibration motor according to the present invention;

fig. 6 is a schematic structural view of a sixth embodiment of a linear vibration motor according to the present invention;

fig. 7 is a schematic structural view of a seventh embodiment of a linear vibration motor according to the present invention;

fig. 8 is an exploded view of an embodiment of a linear vibration motor based on the driving apparatus of fig. 2.

Description of reference numerals:

1-outer shell 11-upper shell;

12-a lower shell; 2-a coil;

4-a magnetic circuit system; 41a, 41 b-radial magnets;

42-parallel magnets; 43-a balanced magnet assembly;

6-mass block; 7-V-shaped elastic sheets;

8-FPCB; 9-a limiting block;

10-a block; 5-shielding sheet.

S-clearance; 111-a magnetically permeable portion;

3-an iron core; 431-a first magnet;

432-a second magnet; 121-a magnetic permeable part;

an S-gap.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Fig. 1 is a simplified structural diagram of an embodiment of a linear vibration motor according to the present invention, in which a driving apparatus portion of the linear vibration motor is mainly shown, and an arrow direction is a magnetizing direction of a corresponding magnet.

As shown in fig. 1, the linear vibration motor includes a housing 1, and a mass 6 and a driving device, etc., which include a Halbach (Halbach) array and a coil 2, both housed in the housing 1.

In order to facilitate the assembly of the linear vibration motor, the housing 1 includes an upper case 11 and a lower case 12, which are fastened and coupled together.

The coil 2 is fixed relative to the lower case 12, and this may be to fix and bond the coil 2 to the lower case 12, or to fix and bond the coil 2 to the lower case 12 through insulating paper.

The plane in which the coil 2 lies is parallel to the direction of vibration, so the direction of the centre line of the coil 2 will be perpendicular to the direction of vibration, which in the embodiment shown in fig. 1 is the left-right direction and the direction of the centre line of the coil 2 is the up-down direction.

The coil 2 has a first side 21 and a second side 22, both sides 21, 22 may be perpendicular to the direction of vibration to increase the effective length of the coil 2 in interaction with the halbach array, i.e. in the direction perpendicular to the plane of the paper in the embodiment shown in fig. 1.

The first side portion 21 and the second side portion 22 may be straight sides or circular arc sides, and for the circular arc sides, the circular arc sides perpendicular to the vibration direction should be understood to have a tangent perpendicular to the vibration direction.

In order to enhance the reaction force of the ampere force under the condition of the same magnetic field intensity, the coil 2 may be rectangular, and the rectangular shape may be arc-shaped at four corners based on the requirement of winding, and the first side portion 21 and the second side portion 22 are long side portions of the coil 2, so as to increase the effective length of the coil 2.

The halbach array is an array in which radial magnets and parallel magnets are arranged and combined together, wherein the magnetizing directions of all the radial magnets 41a and 41b of the halbach array are perpendicular to the plane where the coil 2 is located, and the magnetizing directions of all the parallel magnets 42 of the halbach array are parallel to the vibration direction, so that the coil 2 is located on one side of a generated strong magnetic field.

Since this array can generate a single-sided magnetic field so as to generate the strongest magnetic field on one side with a small number of magnets, when the coil 2 is disposed on the side of the halbach array on the side of the strong magnetic field, the magnetic field strength at which the coil 2 is disposed can be effectively increased, and further, the driving force for driving the vibrator to vibrate repeatedly can be increased.

The halbach array may comprise only one base unit interacting with the coil 2 to simplify the structure and reduce space usage. As shown in fig. 1, one basic unit of the halbach array includes two radial magnets 41a, 41b and one parallel magnet 42 arranged in the vibration direction, wherein, according to the arrangement of the halbach array, the parallel magnet 42 should be sandwiched between the two radial magnets 41a, 41b, the magnetization direction of the radial magnet 41a is from bottom to top, that is, the lower end of the radial magnet 41a is an S pole and the upper end is an N pole, the magnetization direction of the radial magnet 41b is from top to bottom, that is, the lower end of the radial magnet 41b is an N pole and the upper end is an S pole, and the magnetization direction of the parallel magnet 42 is from left to right, that is, the left end is an S pole and the right end is an N pole.

In another embodiment, the magnetization direction of the radial magnet 41a may be from top to bottom, the magnetization direction of the radial magnet 41b may be from bottom to top, and the magnetization direction of the parallel magnet 42 should be reversed to point from right to left to generate a strong magnetic field at the side where the coil 2 is located.

The radial magnet 41a corresponds to the first side portion 21, and the radial magnet 41b corresponds to the second side portion 22, so that, taking the magnetizing direction shown in fig. 1 as an example, the magnetic lines of force emitted by the radial magnet 41b can pass through the second side portion 22 at least partially in the direction having the vertical component, and the magnetic lines of force returning to the radial magnet 41a can pass through the first side portion 21 at least partially in the direction having the vertical component, thereby generating the driving force in the vibration direction.

Further, it is also possible to align the first side 21 with the radial magnet 41a and to align the second side 22 with the radial magnet 41b, wherein the alignment is set such that the first side 21 is located within a coverage of a projection of the radial magnet 41a on a plane where the coil 2 is located in the vibration direction, and the second side 22 is located within a coverage of a projection of the radial magnet 41b on a plane where the coil 2 is located in the vibration direction. Thus, also taking the magnetizing direction shown in fig. 1 as an example, the magnetic lines of force emitted from the radial magnet 41b can mostly pass through the second side portion 22 in a substantially vertical direction, and the magnetic lines of force returning to the radial magnet 41a can mostly pass through the first side portion 21 in a substantially vertical direction, thereby achieving effective utilization of the driving device.

Furthermore, the two radial magnets 41a and 41b may be further disposed symmetrically with respect to a middle section of the coil 2 perpendicular to the vibration direction, which passes through the center line of the coil 2, to improve the force applied to the vibrator and the balance of the force applied thereto.

Thus, according to fig. 1, when the direction of the current in the coil 2 is such that the current in the first side 21 is directed from the outside to the inside and the current in the second side 22 is directed from the inside to the outside, the coil 2 will apply a reaction force of an ampere force to the magnetic circuit system 4 to the left. When the current in the coil 2 is reversed with respect to that shown in fig. 1, the reaction force of the ampere force is shifted to the right, and the vibrator is driven to vibrate repeatedly.

However, also due to the action of the strong magnetic field generated by the halbach array, the devices such as the magnetic conductive part of the coil 2 and the lower case 12, which can generate a force with the halbach array, apply a downward attraction force to the halbach array and further to the entire vibrator, and the downward attraction force interferes with the movement track of the vibrator in the vibration direction, so that the designed resonance frequency is deviated from the actual situation, and the elastic piece of the linear vibration motor is also largely damaged, therefore, as shown in fig. 1, the upper case 11 is provided with the magnetic conductive part 111, and the driving device is provided with the balance magnet assembly 43, so that the upward attraction force is applied to the balance magnet assembly 43 through the magnetic conductive part 111, and further to the entire vibrator, so as to balance the above-mentioned downward attraction force, and further to solve the problem of interfering with the movement track of the vibrator while increasing the driving force.

The halbach array and the balance magnet assembly 43 constitute the magnetic circuit system 4 of the linear vibration motor, in which the magnetic conductive portion 111 and the coil 2 are provided on both sides of the magnetic circuit system 4.

In the embodiment shown in fig. 1, the upper case 11 is entirely made of a magnetic conductive material, and therefore, the top of the upper case 11 parallel to the lower case 12 will be the magnetic conductive part 111.

In another embodiment, the upper case 11 may also include two parts, that is, an upper case body and a shielding plate disposed on the upper case body, the shielding plate is disposed on two sides of the magnetic circuit system 4 as the magnetic conduction portion 111 and the coil 2, and the shielding plate may be disposed on an inner wall and/or an outer wall of the upper case body.

The balance magnet assembly 43 is also fixed relative to the mass 6, i.e., relative to the halbach array, to form part of a vibrator, which may include one magnet or more than two magnets (including two magnets). The balance magnet assembly 43 should be disposed adjacent to the magnetic permeable portion 111 with respect to the coil 2, i.e., the balance magnet assembly 43 is disposed adjacent to the magnetic permeable portion 111 in a direction perpendicular to the plane of the coil 2, so as to avoid the generation of force between the coil 2 and the balance magnet assembly 43 as much as possible.

The balance magnet assembly 43 includes at least one first magnet 431, wherein all the first magnets 431 have the same magnetizing direction and are perpendicular to the plane of the coil, so that the magnetic conductive portion 111 can generate an upward attractive force to the balance magnet assembly 43.

In the embodiment shown in fig. 1, the balance magnet assembly 43 has a first magnet 431, and the magnetization direction of the first magnet 431 is from bottom to top, i.e., the top is the N-pole, and the bottom is the S-pole.

In another embodiment, the first magnet 431 of the balance magnet assembly 43 may be magnetized from top to bottom, i.e., the top is the S-pole and the bottom is the N-pole.

The balance magnet assembly 43 may be symmetrical with respect to a middle section of the coil 2 perpendicular to the vibration direction to avoid generating a torque that rotates the vibrator.

Further, the entire driving device may be symmetrical with respect to a middle section of the coil 2 perpendicular to the vibration direction.

In the embodiment shown in fig. 1, the first magnet 431 is disposed on the surface of the parallel magnet 42 facing the magnetic permeable part 111.

Further, the surface of the parallel magnet 42 facing the magnetic conductive portion 111 is lower than the surfaces of the radial magnets 41a and 41b facing the magnetic conductive portion 111, so that the balance magnet assembly 43 can be embedded in the groove formed on the magnetic conductive portion 111 side of the halbach array, and the surface of the balance magnet assembly 43 facing the magnetic conductive portion 111 is flush with the surfaces of the radial magnets 41a and 41b facing the magnetic conductive portion 111, so as to reduce the influence on the gap S and ensure that the vibration of the oscillator is not affected.

In order to converge the magnetic lines of force in the magnetic field space in which the coil 2 is located, so as to further enhance the magnetic field strength on that side, in this embodiment, the lower case 12 includes a lower case body (non-magnetic conductive material), and a shielding sheet provided on the outer wall of the lower case body as a magnetic conductive portion 121, and the magnetic conductive portion 121 is provided on the same side of the halbach array as the coil 2.

Since the linear vibration motor of the present invention is provided with the balance magnet assembly 43, the shield plate as the magnetic conductive part 121 may be provided on the inner wall of the lower case 12 as long as the upward attractive force and the downward attractive force to the vibrator are balanced by the arrangement.

In another embodiment of the present invention, the lower case 12 may be integrally formed of a magnetic conductive material, so that the lower case 12 may be used as the magnetic conductive part 121 as a whole.

Fig. 2 is a schematic structural view of another embodiment of a linear vibration motor according to the present invention, which mainly shows a driving apparatus portion of the linear vibration motor, and in which an arrow direction is a magnetizing direction of a corresponding magnet.

As shown in fig. 2, the main difference between this embodiment and the embodiment shown in fig. 1 is that the driving device further includes an iron core 3, and the iron core 3 is also fixed relative to the lower case 12 and forms an electromagnet with the coil 2 to generate a magnetic field when the coil 2 is energized, thereby generating a magnetic force action on the halbach array.

In the embodiment in which the coupling lower case 12 has the magnetically permeable part 121, the iron core 3 may be in contact with or fixedly connected to the magnetically permeable part 121.

By providing the magnetic conductive portion 121, the magnetic lines of force can be converged, so that the magnetic field intensity on the coil 2 side can be enhanced.

And the iron core 3 is brought into contact with the magnetic conductive portion 121, the magnetic resistance can be reduced.

In the embodiment shown in fig. 2, the magnetic conductive part 121 is disposed on the outer wall of the lower case, so that the iron core 3 can be fixedly connected to the magnetic conductive part 121 through the opening of the lower case.

In the embodiment shown in fig. 2, the coil 2 and the core 3 are each fixedly attached to the lower case 12.

In other embodiments, the coil 2 may also be fixedly connected to the core 3.

The core 3 may include a portion located in the central hole of the coil 2 to improve the force of the electromagnet.

Further, the iron core 3 may further include a portion located on a side of the coil 2 facing away from the magnetic circuit system 4, so that the iron core 3 has an inverted T shape. In this embodiment the coil 2 may be fixedly connected directly to a part of the core.

Further, the iron core 3 includes a side wall portion surrounding the coil 2 on the outside, in addition to a portion located in the central hole of the coil 2 and a portion located on a side of the coil 2 facing away from the magnetic circuit system 4, that is, the iron core 3 forms an accommodating groove, and the coil 2 can be embedded in the accommodating groove 34.

As described above, according to fig. 2, when the direction of the current in the coil 2 is such that the current in the first side portion 21 is directed inward from the outside and the current in the second side portion 22 is directed outward from the inside, the electromagnet applies a magnetic force (repulsive force) to the radial magnet 41a to the left and also applies a magnetic force (attractive force) to the radial magnet 41b to the left, both directions being the same, and the direction of the reaction force of the ampere force applied to the magnet assembly 4 by the coil 2 also coincides with the direction of the magnetic force according to the left-hand rule.

When the current in the coil 2 is reversed with respect to that shown in fig. 2, the reaction forces of the magnetic force and the ampere force F1 are also reversed, i.e., both are directed to the right side, and a driving force for repeating vibration is given to the vibrator.

As is apparent from the above description, in the linear vibration motor according to the present invention, the driving force for driving the vibrator to repeatedly vibrate is equal to the sum of the reaction force of the ampere force and the total magnetic force, and therefore, according to the aspect of the present invention, the driving force to be supplied to the vibrator can be further increased.

In this embodiment, the downward attractive force applied by the core 3 to the halbach array can also be balanced by the magnetically permeable section 111 against the upward attractive force applied by the balance magnet assembly 43.

Fig. 3 is a schematic structural view of a third embodiment of the linear vibration motor according to the present invention, showing another structure of the balance magnet assembly 43, and the arrow direction is a magnetizing direction of the corresponding magnet.

As shown in fig. 3, this embodiment is different from the embodiment shown in fig. 1 and 2 in that the first magnet 431 of the balance magnet assembly 43 covers the entire surface of the halbach array facing the magnetic conductive part 111, and the balance magnet assembly 43 may cover the entire surface of the halbach array facing the magnetic conductive part 111 by one first magnet 431 as shown in fig. 3, or may cover the entire surface of the halbach array facing the magnetic conductive part 111 by two or more first magnets 431.

Fig. 4 is a schematic structural view of a third embodiment of the linear vibration motor according to the present invention, showing another structure of the balance magnet assembly 43, and the arrow direction is a magnetizing direction of the corresponding magnet.

According to fig. 4, this embodiment is different from the embodiment shown in fig. 1 and 2 in that the balance magnet assembly 43 includes three first magnets 431, one of which is disposed on the surface of the parallel magnet 42 facing the magnetically permeable part 111, and the other two first magnets 431 are disposed on both sides of the halbach array in the vibration direction, so that the balance magnet assembly 43 is symmetrical with respect to a middle section of the coil 2 perpendicular to the vibration direction.

Fig. 5 is a schematic structural view of a fourth embodiment of the linear vibration motor according to the present invention, showing another structure of the balance magnet assembly 43, and the arrow direction is a magnetizing direction of the corresponding magnet.

According to fig. 5, this embodiment is different from the embodiment shown in fig. 1 and 2 in that the balance magnet assembly 43 includes two first magnets 431, and the two first magnets 431 are disposed at both sides of the halbach array in the vibration direction, so that the balance magnet assembly 43 is symmetrical with respect to a middle section of the coil 2 perpendicular to the vibration direction.

The above non-restrictive examples of embodiments in which the balanced magnet assembly 43 has only the first magnet 431 have been given, on the basis of which the balanced magnet assembly 43 may further comprise a second magnet having a magnetizing direction parallel to the vibration direction.

Fig. 6 is a schematic structural view of a fifth embodiment of the linear vibration motor according to the present invention, in which an implementation structure of the balance magnet assembly 43 having the second magnet 432 is shown, and the arrow direction is a magnetizing direction of the corresponding magnet.

As shown in fig. 6, the balanced magnet assembly 43 includes a first magnet 431 and two second magnets 432, the first magnet 431 is magnetized from bottom to top, the left second magnet 432 is magnetized from left to right, and the right second magnet 432 is magnetized from right to left. Fig. 7 is a schematic structural view of a sixth embodiment of a linear vibration motor according to the present invention, which shows another structure in which the balance magnet assembly 43 has the second magnet 432, and the arrow direction is a magnetizing direction of the corresponding magnet.

As shown in fig. 7, the balanced magnet assembly 43 includes at least two second magnets 432, and all the second magnets 432 constitute at least one pair of magnetic pairs, and the two second magnets 432 of each pair of magnetic pairs are arranged side by side in the vibration direction and have opposite magnetization directions.

Due to the magnetic structure, the magnetic lines of force of each second magnet 432 are distributed in the direction toward the magnetic conductive portion 111, which is beneficial to enhance the upward attraction force generated by the magnetic conductive portion 111 on the balance magnet assembly 43, and thus the effect of balancing the above-mentioned downward attraction force by the upward attraction force is obtained.

In the embodiment shown in fig. 7, the balance magnet assembly 43 is formed of two pairs of opposed magnets by three second magnets 432.

In the embodiment shown in fig. 7, all of the second magnets 432 are located on the surface of the halbach array facing the magnetically permeable portion 111.

In the embodiment shown in fig. 7, the balance magnet assembly 43 has two first magnets 431, and the two first magnets 431 are disposed on both sides of the halbach array in the vibration direction.

The linear vibration motor of the present invention may include one of the above-described driving devices, and may also include two or more (including two) driving devices in another embodiment, the two or more driving devices being arranged in order in the vibration direction, which will further increase the driving force that can be supplied to the vibrator as the spatial size allows.

Further, for embodiments where more than two driving devices are provided, the halbach arrays of two adjacent driving devices may share one radial magnet, and correspondingly, two adjacent sides of two adjacent coils 2, i.e. the second side 22 of one coil 2 and the first side 21 of an adjacent coil 2, will be aligned with the same radial magnet. The coils of the driving devices are connected in a way that the current flow directions of the coils meet the requirement that the driving force in the same direction is applied to the vibrators at the same time, and the effect of superposing the driving force can be obtained.

Fig. 8 shows a vibrator of a linear vibration motor, which includes a magnetic circuit 4, a mass 6, and two V-shaped springs 7, wherein the magnetic circuit 4 is fixed with respect to the mass 6, the two V-shaped springs 7 are respectively disposed on two sides of the mass 6 in a vibration direction, and have opposite opening directions, wherein one free end of each V-shaped spring 7 is fixedly connected to the mass 6, and the other free end is fixedly connected to the upper case 11.

Two V-shaped elastic sheets 7 are arranged along opposite directions, so that the stability of vibrator vibration is improved, and resonance is reduced.

Also shown in fig. 8 is a stator of the linear vibration motor, including the coil 2, a flexible circuit board 8(FPCB), the flexible circuit board 8 exposing leads and/or pads via the lower case 12.

Fig. 8 also shows other parts of the linear vibration motor, a stopper 9, a stopper 10, and the like.

The above embodiments mainly focus on differences from other embodiments, but it should be clear to those skilled in the art that the above embodiments can be used alone or in combination with each other as needed.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein were chosen in order to best explain the principles of the embodiments, the practical application, or technical improvements to the techniques in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the invention is defined by the appended claims.

Claims

1. A linear vibration motor comprising a housing (1) and a drive device housed in the housing (1), the housing (1) having a magnetically permeable portion (111), the drive device comprising a coil (2), a halbach array and a balance magnet assembly (43), wherein the halbach array and the balance magnet assembly (43) are part of a vibrator of the linear vibration motor; the plane where the coil (2) is located is parallel to the vibration direction, the coil (2) and the magnetic conduction part (111) are respectively arranged on two sides of the Halbach array, and the coil (2) is located on one side of the Halbach array in a strong magnetic field; the balance magnet assembly (43) is fixed relative to the Halbach array and is arranged close to the magnetic conduction part (111) relative to the coil (2), the balance magnet assembly (43) comprises at least one first magnet (431), and all the first magnets (431) have the same magnetizing direction and are perpendicular to the plane where the coil (2) is located.

2. The linear vibration motor according to claim 1, wherein the halbach array has three magnets arranged in the vibration direction, respectively two radial magnets (41a, 41b) and one parallel magnet (42), wherein the two radial magnets (41a, 41b) have opposite magnetization directions and are perpendicular to a plane in which the coil (2) is located, one radial magnet (41a) corresponds to the first side portion (21) of the coil (2), the other radial magnet (41b) corresponds to the second side portion (22) of the coil (2), and the magnetization direction of the parallel magnet (42) is parallel to the vibration direction.

3. A linear vibration motor according to claim 2, wherein said first side portion (21) and said second side portion (22) are perpendicular to said vibration direction, and said driving means is symmetrical with respect to a middle section of said coil (2) perpendicular to said vibration direction.

4. A linear vibration motor according to claim 2, wherein said driving means further comprises an iron core (3), said iron core (3) constituting an electromagnet with said coil (2), said iron core (3) comprising a portion located in a central hole of said coil (2).

5. The linear vibration motor according to claim 1, wherein the halbach array has parallel magnets (42) whose magnetizing directions are parallel to the vibration direction, and at least a part of the first magnets (431) of the balance magnet assembly (43) is disposed on the surfaces of the parallel magnets (42) facing the magnetically permeable part (111).

6. A linear vibration motor according to claim 1, wherein said balance magnet assembly (43) further comprises at least one second magnet (432), and a magnetizing direction of said second magnet (432) is parallel to said vibration direction.

7. A linear vibration motor according to claim 6, wherein said balance magnet assembly (43) comprises at least two second magnets (432), and all second magnets (432) constitute at least one pair of opposed magnets, the two second magnets (432) of each pair of opposed magnets being arranged side by side in said vibration direction and having opposite magnetization directions.

8. A linear vibration motor according to claim 1, wherein the housing (1) further has another magnetically permeable portion (121), the other magnetically permeable portion (121) being located on the same side of the halbach array as the coil (2).

9. The linear vibration motor according to any one of claims 1 to 8, wherein the linear vibration motor includes two or more of the driving devices, and the two or more driving devices are arranged in sequence in the vibration direction.

10. A linear vibration motor according to claim 9, wherein the halbach arrays of two adjacent driving means share one radial magnet, wherein the radial magnet is a magnet in which the magnetization direction of the halbach array is perpendicular to the plane in which the coil (2) is located.