CN116613952A - Linear vibration motor - Google Patents

Abstract

The present invention provides a linear vibration motor, comprising: a movable part, a suspension device and a fixed part; the movable part comprises at least one magnet group, and the fixed part comprises at least one coil, at least one magnetic conduction assembly and a shell; the magnet group of the movable part, the coil of the fixed part and the magnetic conduction assembly are arranged in opposite directions through gaps, and the at least one magnetic conduction assembly is positioned above, below or at the same time above and below the magnet group; the suspension device comprises two sheet springs which are respectively positioned at two sides of the movable part, one side of each sheet spring is connected with the movable part, the other side is connected with the fixed part, and the suspension device is in a straight sheet shape in a non-acting natural state and has no bending characteristic at the whole length of the sheet spring at the joint of the two sides.

Description

Linear vibration motor

Technical Field

The invention relates to a linear vibration motor.

Background

With the popularity of intelligent mobile devices, such as mobile phones, tablet computers and wearable devices, the use of a linear vibration motor (Linear vibration motor) as a vibration source has long become a mainstream technology for touch feedback because of its advantages such as faster response and more power saving. In view of the trend of thinning and thinning electronic products, how to increase the magnetic field strength and maintain the lifetime of the products under the condition of thinning and thinning is also becoming a ring of increasing importance in the specification performance of linear vibration motors.

The conventional linear vibration motor structure is basically composed of a movable part, a fixed part and a suspension system; for example, in the most simplified embodiment, the movable portion may be a magnet set, the fixed portion may be a coil set, and the suspension system may be a spring set. In other words, the structure of the linear vibration motor determines the vibration mode in which the magnet set is controlled by the coil set to move in a linear manner with respect to the coil set to reach the resonance frequency. In addition, in the linear vibration motor, at least one magnetic conduction component is often arranged in the fixing part to improve the vibration effect.

On the premise of lightening and thinning the product, the thickness of the product is compressed, and the thickness of the magnet and the coil must be reduced first, and the magnetic field strength is also directly reduced. To overcome this phenomenon, the current technology is often to increase the magnetic field strength of the product by adding a magnetic conductive component to guide the magnetic force lines to the maximum through the coil. However, this solution, while effective, extends to other problems as well.

For example, adding a magnetic conductive element can naturally effectively increase the magnetic field strength, but the opposite magnetic attraction force also causes the load of the suspension system of the linear vibration motor, and the existing common non-contact suspension system is mainly composed of spring plates. Fig. 1A to 1C show the sheet-shaped suspension spring, the L-shaped suspension spring, and the C-shaped suspension spring intentions, respectively. In order to achieve the aim of parallel movement, the configuration of the elastic piece type suspension device is mostly U-shaped or C-shaped, and the U-shaped elastic piece and the C-shaped elastic piece have turning characteristics in configuration; table 1 shows the natural frequencies of different dome suspension configurations. The higher the natural frequency, the more rigid the spring leaf suspension configuration, as shown in table 1; therefore, the more turning features, the weaker the rigidity of the elastic sheet UZ direction (direction perpendicular to the XY plane), as shown in fig. 1A, 1B, and 1C, the same carrier and distance Y, A; x is the length +2 of the turning part of the 2-side elastic sheet, and UX represents the direction parallel to the X axis.

TABLE 1

The common solution for overcoming the rigidity deficiency of the elastic sheet UZ direction is as follows:

firstly, matching the corresponding size and gap of the magnetic conduction assembly according to the bearable rigidity of the suspension system in the UZ direction; the method has the advantages that the magnetic field intensity is effectively increased, but the disadvantage that the rigidity factor in the UZ direction of the suspension system needs to keep a gap, so that the magnetic conduction effect of the magnetic conduction assembly is reduced, and the design thickness of the product is limited.

Secondly, adding other rigid support components in the UZ direction, such as components of a shaft, the number of elastic sheets, magnetic fluid and the like; the method has the advantages that the magnetic conduction assembly can be placed at the position of the coil through which the magnetic force lines are guided to be maximized, but has the defects of easy generation of the derivative design problems of increased assembly difficulty, friction (nonlinearity), material characteristics and the like; in particular, when adding shaft assemblies, there will be structural limitations in thickness and friction (non-linearity) problems will occur; when the number of the spring pieces is increased, the assembly difficulty is increased, and the length and width of the product are limited; when the magnetic fluid (entity damping) is added, the magnetic fluid is easily affected by temperature, and the verification of the product characteristics and the temperature reliability is limited.

Therefore, on the premise of lightening and thinning the linear vibration motor product, the aim of increasing the magnetic field strength of the product is to design a linear vibration motor without increasing the supporting components except the elastic sheet and the magnetic conduction component, so that the magnetic conduction component can be placed at a position capable of guiding magnetic force lines to be maximized to pass through the coil, and the linear vibration motor is a challenge facing the current industry.

Disclosure of Invention

An embodiment of the present invention discloses a linear vibration motor, comprising: a movable part, a suspension device and a fixed part; the movable part comprises at least one magnet group, the magnet group comprises at least three magnets which are arranged in a spaced mode, the magnetization directions of the magnets are up and down, the polarities of the adjacent magnets are opposite when the magnets are arranged, and the fixed part comprises at least one coil, at least one magnetic conduction assembly and a shell; the magnet group of the movable part, the coil of the fixed part and the magnetic conduction assembly are arranged in opposite directions through gaps, the two side polar surfaces of the magnet group are opposite to the coil of the fixed part and the magnetic conduction assembly, the size of the magnetic conduction assembly of the fixed part in the non-moving direction is required to be larger than that of the magnet group in the non-moving direction, the at least one magnetic conduction assembly is positioned above or below the magnet group, and when the number of the at least one magnetic conduction assembly exceeds one, the magnetic conduction assemblies can be respectively arranged above and below the magnet group; the suspension device comprises two sheet springs, wherein the two sheet springs are respectively positioned at two sides of the movable part, one side of each sheet spring is connected with the movable part, and the other side of each sheet spring is connected with the fixed part, so that the movable part is supported by the suspension device and moves freely relative to the fixed part, the height of the connecting end of each sheet spring is equal to the height of the connecting ends of the movable part and the fixed part, and the suspension device is in a straight sheet shape in an unactuated natural state and has no bending characteristic at the whole length of the sheet spring at the joint of the two sides.

In a preferred embodiment, the magnetic conductive component is provided with at least one hole.

In a preferred embodiment, the hole is a rectangular hole, and four sides of the hole are parallel to four sides of the magnet set respectively; and under the condition that the width and the external dimension of the hole are fixed, the dimension of the hole in the X direction is more than or equal to 0 and less than or equal to 3/4 of the dimension of the hole in the X direction of the hole is the middle magnet; under the condition that the length and the external dimension of the hole are fixed, the dimension of the Y direction of the hole is not less than 0 and not more than the width of the Z direction relative magnet of the hole.

In a preferred embodiment, the hole may be a groove-shaped hole that cuts off the upper edge or the lower edge of the magnetic conductive component, so that the hole of the magnetic conductive component is in a groove shape; and, the magnetic conduction assembly with the groove type hole can be used as the end face from both sides of the magnetic conduction assembly, and the end face of the groove type hole can also be used as the end face.

In a preferred embodiment, the hole patterns of the magnetic conductive components can be stacked to form a composite hole; the composite hole is a union area formed by stacking two or more holes, the composite hole can be stacked on one side and two sides, and the final composite hole can be a closed hole or a groove hole.

Drawings

FIGS. 1A-1C illustrate the sheet-like suspension spring, L-shaped suspension spring, and C-shaped suspension spring intentions, respectively;

FIG. 2 is a schematic view showing a state in which a movable portion of a linear vibration motor according to the present invention is connected to a suspension device;

FIG. 3 is a schematic cross-sectional view showing the structure of a fixing portion of the linear vibration motor of the present invention;

FIG. 4 is a schematic diagram of an approximately closed magnetic circuit formed by a magnet assembly and a magnetic conductive assembly of a linear vibration motor according to the present invention;

FIG. 5A is a schematic diagram showing the arrangement of the magnetic conductive assembly and the magnet assembly of the linear vibration motor according to the present invention;

FIG. 5B is a graph showing the relationship between the magnetic restoring force of the linear vibration motor and the displacement distance of the end face of the magnet;

fig. 6A to 6C are schematic views showing the arrangement of holes in the magnetic conductive member of the linear vibration motor according to the present invention

Fig. 7A to 7F are schematic diagrams of various embodiments of the magnetic conductive assembly under the condition that the width and the external dimension of the hole are fixed;

FIGS. 8A to 8B are schematic diagrams showing the relationship between the magnetic restoring force in the X direction, the magnetic attraction force in the Z direction and the displacement distance of the end face of the magnet under the fixed hole width;

fig. 9A to 9H are schematic diagrams of various embodiments of the magnetic conductive assembly under the condition that the hole length and the external dimension are fixed;

FIGS. 10A to 10B are schematic diagrams showing the relationship between the magnetic restoring force in the X direction, the magnetic attraction force in the Z direction and the displacement distance of the end face of the magnet under the fixed hole length;

FIG. 11 is a schematic diagram of an embodiment of a magnetic conductive assembly set with a slot-type hole for a linear vibration motor according to the present invention;

fig. 12 is a schematic diagram of an embodiment of a magnetic conductive assembly set with composite holes for a linear vibration motor according to the present invention.

Reference numerals illustrate:

101-a magnet;

102-coil;

103-a magnetic conduction assembly;

104-a housing;

105-leaf spring;

105A-a movable portion connecting end;

105B-a fixed part connection end;

105C-full length of the leaf spring;

l1 is the length of the magnetic conduction assembly group;

l2-magnet group length;

l3-magnet group width;

l4-hole width;

c-hole length;

d-displacement distance of the end face of the magnet.

Detailed Description

Further advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure, by describing embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments and details within the scope of the description, which may be modified or varied from various points of view and applications without departing from the spirit of the invention.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the invention to the extent that it can be practiced, since modifications, changes in the proportions, or adjustments of the sizes, which are otherwise, used in the practice of the invention, are included within the spirit and scope of the invention.

Reference is made to fig. 2 and 3. The invention mainly discloses a linear vibration motor. The invention relates to a linear vibration motor, which comprises a movable part, a suspension device and a fixed part. FIG. 2 is a schematic view showing a state in which the movable portion is connected to the suspension device; fig. 3 is a schematic cross-sectional view of the structure of the fixing portion. As shown in fig. 2 and 3, the movable part includes at least one magnet set including at least three magnets 101, and the fixed part includes at least one coil 102, a magnetic conductive component 103 and a housing 104; the magnet group of the movable part and the coil of the fixed part are arranged in opposite directions with gaps, the polar surfaces at two sides of the magnet group are opposite to the coil of the fixed part and the magnetic conduction assembly, the size of the magnetic conduction assembly of the fixed part in the non-moving direction is required to be larger than that of the magnet group in the non-moving direction, the at least one magnetic conduction assembly is positioned above or below the magnet group, and when the number of the at least one magnetic conduction assembly exceeds one, the magnetic conduction assemblies can be respectively arranged above and below the magnet group; the suspension device comprises two leaf springs 105 which are respectively positioned at two sides of the movable part, one side of each leaf spring is connected with the movable part, and the other side is connected with the fixed part, so that the movable part is supported by the suspension device and can freely move relative to the fixed part. As shown in fig. 2, the movable portion connecting end 105A and the fixed portion connecting end 105B of the leaf spring 105 are both equal in height to the positions where the movable portion and the fixed portion are connected, so that the suspension device is in a straight-line leaf shape in a non-operating natural state and the whole length 105C of the leaf spring at the two side connection positions has no bending feature.

FIG. 4 is a schematic diagram of an approximately closed magnetic circuit formed by a magnet assembly and a magnetic conductive assembly of a linear vibration motor according to the present invention; FIG. 5A is a schematic diagram showing the arrangement of the magnetic conductive assembly and the magnet assembly of the linear vibration motor according to the present invention; FIG. 5B is a graph showing the relationship between the magnetic restoring force of the electric linear vibration motor and the displacement distance of the end face of the magnet. Wherein L1 is the length of the magnetic conduction assembly, L2 is the length of the magnet group, and d is the displacement distance of the end face of the magnet.

It should be noted that, during the vibration process, the Lorentz force (Lorentz force) generated by the magnetic field action of the magnet set of the movable portion when the coil set is applied with current is applied between the magnet set of the movable portion and the coil set and the magnetic conductive assembly set of the fixed portion, so that the movable portion and the suspension device are displaced. In addition, the magnetic conduction assembly group and the magnet group form an approximately closed magnetic circuit, as shown in fig. 4; when the movable part and the suspension device are displaced, a magnetic restoring force of the movable part relative to the fixed part can be additionally provided, as shown in fig. 5B, and the magnetic restoring force can assist the leaf spring suspension device to bring the movable part back to the mechanical origin.

In order to increase the magnetic field strength and enable the magnetic conduction assembly group to be placed at the position of the passing coil which guides magnetic force lines to maximize, the invention needs to overcome the problem of insufficient rigidity of the sheet spring in the UZ direction. The main operation principle is described as follows:

derived from the section moment of inertia equation:

Kz/Kx＝Iz/Ix＝(bh3/12)/(b3h/12)＝(h/b)2

wherein b is the width of the leaf spring, i.e. the width in the UX direction, h is the thickness of the leaf spring, i.e. the thickness in the UZ direction, K is the spring constant of the leaf spring; in other words, the greater the difference in the ratio of h to b, the greater the stiffness of the leaf spring in the UZ direction. Based on the shape and specification of the sheet spring, the rigidity of the sheet spring in the UZ direction can be supported, and the magnetic attraction force of the magnetic conduction assembly in the UZ direction can be increased.

However, the problem of stress increase due to the increase in the spring constant of the leaf spring is also derived by increasing the thickness dimension of the leaf spring to satisfy the increase in rigidity in the UZ direction (i.e., kz increase). According to Hooke's Law: f=kx, and under the condition that X is unchanged, the rise of K will cause the rise of F, which will cause the rise of stress σ, since the rise of f=f/a. The problem of stress rising directly affects the damage of the elastic component caused by fatigue of the elastic piece of the linear vibration motor under the stroke reciprocating action condition.

For the above-mentioned fatigue failure reasons, the present invention needs to increase the force of a spring constant (Km) of the linear vibration motor except the existing suspension device under the existing structure of the linear vibration motor (in other words, without adding other supporting components), so as to reduce the spring constant of the existing suspension device (i.e. the leaf spring) from Ks to Ks ', that is, ks=ks' +km, so as to achieve the goal of reducing the stress, and further reduce the fatigue damage effect of the elastic components.

Therefore, as described above, the present invention forms an approximately closed magnetic circuit with the magnet assembly by the magnetic conductive assembly, so that when the movable portion is displaced, a magnetic restoring force of the movable portion relative to the fixed portion is provided, and the movable portion returns to its mechanical origin; more specifically, the magnetic restoring force can be used as a spring constant (Km) other than the suspension device, so that the elastic system of the linear vibration motor does not need to rely on the suspension device to bear the reciprocating stroke.

Further, when the end surfaces of the magnetic conduction assembly group and the magnet group are aligned (d=0), the magnetic conduction assembly group of the fixed part can provide zero magnetic restoring force of the magnet group of the movable part; when the movable part magnet group moves rightwards, the right end surface of the magnet group and the right end surface of the magnetic conduction assembly group generate a restoring force for leftwards movement under the action of magnetic attraction generated by the magnetic field guidance; otherwise, the corresponding restoring force is provided in the opposite direction.

However, when the magnetic restoring force provided by the magnet set and the two sides of the magnetic conduction assembly still cannot meet the Km design requirement, on the premise that the magnet set comprises at least three magnets, holes can be added from the design configuration of the magnetic conduction assembly, and the magnetic attraction force can be changed by virtue of the design of one technical feature.

Fig. 6A to 6C are schematic diagrams illustrating the arrangement of holes on the magnetic conductive component of the linear vibration motor according to the present invention. As shown in fig. 6A to 6C, the present invention can further increase the required magnetic restoring force by increasing the magnetic attraction force generated by the end face of X, Y direction and the magnet set in the way of arranging the holes on the magnetic conductive component; furthermore, the magnetic attraction force of the magnetic conduction assembly provided with the holes to the UZ direction is reduced, and the effect of reducing Ks' design requirement can be achieved. Furthermore, the desired magnetic attraction force can be adjusted by changing the position of the hole and the size of the hole. Wherein, the X direction is defined as the length direction, the Y direction is defined as the width direction, and the direction perpendicular to the X-Y plane is defined as the Z direction; c is the size of the hole in the X direction (length), L4 is the size of the hole in the Y direction (width), and L3 is the size of the magnet group in the Y direction (width). The core technical characteristics of the invention are that the needed magnetic restoring force is increased by the magnetic attraction force generated by the X, Y direction end face and the magnet group which are increased in a mode of arranging the hole on the magnetic conduction assembly, so that the magnet which generates magnetic force change when the hole acts is defined as the Z-direction relative magnet of the hole; in other words, the Z-direction opposing magnet of the hole means that the area covered by the magnet and the hole in the natural state where the magnet does not operate=intersects in the Z-direction, and the projection of the magnet in the Z-direction should overlap with the boundary of the hole.

As mentioned above, the location and size of the holes may affect the strength of the magnetic attraction. Fig. 7A to 7F are schematic diagrams of various embodiments of the magnetic conductive assembly under the condition that the width and the external dimension of the hole are fixed; FIGS. 8A to 8B are schematic diagrams showing the relationship between the magnetic restoring force in the X direction, the magnetic attraction force in the Z direction and the displacement distance of the end face of the magnet under the fixed hole width; fig. 9A to 9H are schematic diagrams of various embodiments of the magnetic conductive assembly under the condition that the hole length and the external dimension are fixed; fig. 10A to 10B are schematic diagrams showing the relationship between the magnetic restoring force in the X direction, the magnetic attraction force in the Z direction and the displacement distance of the end face of the magnet under the fixed hole length.

As shown in fig. 7A to 7F and fig. 8A to 8B, the magnetic restoring force required by the relative movement direction can be increased from small (> 0) to 3/4 of the hole Z direction relative to the magnet in the X direction of the magnetic conductive assembly under the condition that the width and the external dimension of the hole are fixed. In addition, the size of the hole is larger than 3/4 of the size of the Z-direction relative magnet of the hole, and reverse magnetic restoring force is generated in the stroke operation process. Fig. 8A to 8B show the relationship between the magnetic restoring force in the X direction, the magnetic attraction force in the Z direction and the displacement distance of the end face of the magnet; the curves of the graph are void-free, type0 (the length of the void is 0.1 mm), type1 (the length of the void is 1/4 of the length of the void in the Z direction relative to the magnet), type2 (the length of the void is 2/4 of the length of the void in the Z direction relative to the magnet), type3 (the length of the void is 3/4 of the length of the void in the Z direction relative to the magnet), and Type4 (the length of the void is equal to the width of the Z direction relative to the magnet) respectively show the sizes and the arrangements of the voids in FIGS. 7A to 7F.

As shown in fig. 9A to 9H and fig. 10A to 10B, the magnetic restoring force required by the relative movement direction of the magnetic conductive component can be increased from small (> 0) to 6/3 of the hole Z direction relative to the magnet under the condition that the length and the external dimension of the hole are fixed. Fig. 10A to 10B show the relationship between the magnetic restoring force in the X direction, the magnetic attraction force in the Z direction and the displacement distance of the end face of the magnet; the curves of the graph are void-free, type0 (the width of the void is 0.1 mm), type1 (the width of the void is 1/3 of the dimension of the void Z relative to the magnet), type2 (the width of the void is 2/3 of the dimension of the void Z relative to the magnet), type3 (the width of the void is equal to the dimension of the void Z relative to the magnet), type4 (the width of the void is 4/3 of the dimension of the void Z relative to the magnet), type5 (the width of the void is 5/3 of the dimension of the void Z relative to the magnet), and Type6 (the width of the void is 6/3 of the dimension of the void Z relative to the magnet) respectively show the width and the arrangement of the voids in FIGS. 9A to 9H.

In other embodiments, the hole of the magnetic conductive component may be a groove-shaped hole to intercept the upper edge or the lower edge of the magnetic conductive component, so that the hole of the magnetic conductive component is in a groove shape. In other words, when the width Y dimension L4 of the middle hole is greater than the width of the magnetic conductive component, it is a groove hole; when the width Y direction dimension L4 of the middle hole is smaller than the width of the magnetic conduction assembly, the middle hole is a closed hole. The magnetic conduction assembly with the groove type holes can be used as end faces from two sides of the magnetic conduction assembly, and the end faces of the groove type holes can also be used as end faces.

Fig. 11 is a schematic diagram of an embodiment of a magnetic conductive assembly set with a groove-type hole of a linear vibration motor according to the present invention. As shown in fig. 11, in this embodiment, the upper magnetic conductive component and the lower magnetic conductive component of the magnetic conductive component set have different specifications; the upper magnetic conduction assembly is provided with a closed hole, and the lower magnetic conduction assembly is provided with two wider closed holes and a narrower groove type hole which is arranged between the two wider closed holes.

In other words, the Y-direction dimensions of the end faces of the upper and lower magnetic conductive members may be the same and symmetrical, or may be different and asymmetrical. Furthermore, the Y-direction dimensions of the end surfaces of the upper and lower magnetic conductive components can be the same and are symmetrical front and back, or can be different and are asymmetrical front and back. Alternatively, the middle holes X, Y of the upper and lower magnetic conductive components may have the same dimension and be symmetrical front and back, or may have different dimensions and be asymmetrical front and back.

Likewise, in various embodiments, the hole patterns of the magnetic conductive members may be stacked on each other to form a composite hole; in other words, the combined area of two or more holes after stacking can be overlapped on one side and two sides, and the final combined hole can be a closed hole or a groove hole.

Fig. 12 is a schematic diagram of an embodiment of a magnetic conductive assembly set with composite holes for a linear vibration motor according to the present invention. As shown in fig. 12, in this embodiment, the upper magnetic conductive component and the lower magnetic conductive component of the magnetic conductive component set have different specifications; the upper magnetic conduction assembly is provided with a closed composite hole, and a T-shaped hole is formed by combining and integrating two closed holes; the lower magnetic conduction assembly is provided with two wider closed holes and a groove type composite hole which is arranged between the two wider closed holes, and the groove type composite hole is formed by combining and integrating the two closed holes and the groove type hole.

Furthermore, the size of the composite holes X, Y can be the same and symmetrical in front-back direction, or can be different and asymmetrical in front-back direction. Further, the composite holes X, Y may have the same dimension and may be asymmetric.

In summary, the linear vibration motor of the invention enables Ks=Ks '+Km condition to be satisfied by the magnetic restoring force formed by the sheet spring, the magnetic conduction assembly and the magnet set under specific conditions, and once Ks' < Ks, the spring constant of the sheet spring of the suspension device can be reduced, so that the sheet spring can meet the requirement of increasing the rigidity supporting strength of the magnetic conduction assembly in the UZ direction, and the problem of fatigue damage caused by overlarge stress is avoided without adding an additional supporting assembly.

However, the above embodiments are merely illustrative of the efficacy of the invention, and not intended to be limiting, as modifications and variations can be made to the above embodiments by persons skilled in the art without departing from the spirit and scope of the invention. Furthermore, the number of components in the embodiments described above is merely illustrative, and is not intended to limit the present invention. The scope of the invention is therefore indicated by the appended claims.

Claims (10)

1. A linear vibration motor, comprising: a movable part, a suspension device and a fixed part;

the movable part comprises at least one magnet group, the magnet group comprises at least three magnets which are arranged in a spaced mode, the magnetization directions of the magnets are up and down, the polarities of the adjacent magnets are opposite when the magnets are arranged, and the fixed part comprises at least one coil, at least one magnetic conduction assembly and a shell;

the magnet group of the movable part, the coil of the fixed part and the magnetic conduction assembly are arranged in opposite directions through gaps, the two side polar surfaces of the magnet group are opposite to the coil of the fixed part and the magnetic conduction assembly, the size of the magnetic conduction assembly of the fixed part in the non-moving direction is required to be larger than that of the magnet group in the non-moving direction, the at least one magnetic conduction assembly is positioned above or below the magnet group, and when the number of the at least one magnetic conduction assembly exceeds one, the magnetic conduction assemblies can be respectively arranged above and below the magnet group;

the suspension device comprises two sheet springs, wherein the two sheet springs are respectively positioned at two sides of the movable part, one side of each sheet spring is connected with the movable part, and the other side of each sheet spring is connected with the fixed part, so that the movable part is supported by the suspension device and moves freely relative to the fixed part, the height of the connecting end of each sheet spring is equal to the height of the connecting ends of the movable part and the fixed part, and the suspension device is in a straight sheet shape in an unactuated natural state and has no bending characteristic at the whole length of the sheet spring at the joint of the two sides.

2. The linear vibration motor according to claim 1, wherein the magnetic conductive member is provided with at least one hole, and a magnet which generates a magnetic force change when the hole is operated is defined as a Z-direction opposing magnet of the hole.

3. The linear vibration motor according to claim 2, wherein the hole is a rectangular hole, and four sides of the hole are parallel to four sides of the magnet set, respectively; and under the condition that the width dimension of the hole is fixed, the dimension of the length direction of the hole is not less than 0 and not more than 3/4 of the length of the Z direction of the hole relative to the magnet.

4. The linear vibration motor according to claim 2, wherein the hole is a rectangular hole, and four sides of the hole are parallel to four sides of the magnet set, respectively; and under the condition that the width dimension of the hole is fixed, the dimension of the length direction of the hole is not less than 0 and not more than 1/2 of the length of the Z direction of the hole relative to the magnet.

5. The linear vibration motor according to claim 2, wherein the hole is a rectangular hole, and four sides of the hole are parallel to four sides of the magnet set, respectively; and under the condition that the width dimension of the hole is fixed, the dimension of the Z direction of the hole relative to the length of the magnet is not more than 1/4 of the dimension of the length direction of the hole relative to the length of the magnet, and is not more than 1/2 of the dimension of the Z direction of the hole relative to the length of the magnet.

6. The linear vibration motor according to claim 2, wherein the hole is a rectangular hole, and four sides of the hole are parallel to four sides of the magnet set, respectively; and under the condition that the length dimension of the hole is fixed, the width dimension of the hole is not less than 0 and not more than the Z direction relative magnet width of the hole.

7. The linear vibration motor according to claim 2, wherein the hole is a rectangular hole, and four sides of the hole are parallel to four sides of the magnet set, respectively; and under the condition that the length dimension of the hole is fixed, the width dimension of the hole is not less than 0 and not more than 2/3 of the Z direction of the hole relative to the width of the magnet.

8. The linear vibration motor according to claim 2, wherein the hole is a rectangular hole, and four sides of the hole are parallel to four sides of the magnet set, respectively; and under the condition that the length dimension of the hole is fixed, the dimension of the Z direction of the hole relative to the width of the magnet is not more than 1/3 of the dimension of the Z direction of the hole relative to the width of the magnet.

9. The linear vibration motor of claim 2, wherein the hole is a groove-shaped hole that cuts off an upper edge or a lower edge of the magnetic conductive member so that the hole of the magnetic conductive member is in a groove shape; the magnetic conduction assembly with the groove type hole can be used as an end face from two sides of the magnetic conduction assembly, and can also be used as an end face from the end face of the groove type hole.

10. The linear vibration motor of claim 9, wherein the hole patterns of the magnetically permeable elements are stacked one above the other to form a composite hole; the composite hole is a union area formed by stacking two or more holes, the composite hole can be stacked on one side and two sides, and the final composite hole can be a closed hole or a groove hole.