CN113972808A

CN113972808A - Linear vibration motor

Info

Publication number: CN113972808A
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: 2022-01-25
Anticipated expiration: 2041-10-27
Also published as: CN113972808B

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 arranged at intervals along a vibration direction, and each annular coil is obliquely arranged along the vibration direction and is suitable for enabling two driving surfaces of the same annular coil to be staggered with each other; the magnetic assembly comprises a plurality of permanent magnets which are arranged on the inner side of the annular coil and are sequentially arranged 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; any one of the driving assembly or the magnetic assembly is a stator, and the other one is a rotor. Through the structure, the attenuation speed of the driving force between the driving assembly and the magnetic assembly 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, handheld game consoles or handheld multimedia entertainment devices, have come into the lives of people. In these portable electronic products, a micro vibration motor is generally used for system feedback, such as incoming call prompt of a mobile phone, vibration feedback of a game machine, and the like.

The existing micro vibration motor generally comprises a shell forming a vibration space, a vibrator (generally comprising a balancing weight and a permanent magnet) which makes linear reciprocating vibration in the vibration space, and a stator which is matched with the vibrator to act.

The vibration principle of the miniature vibration motor is as follows: the permanent magnet of the vibrator generates a magnetic field, the stator coil in the magnetic field is stressed, and the stator is relatively fixed, so that the vibrator can move towards a certain direction under the driving of a reaction force, the current direction of the stator coil is changed, and the vibrator can move towards the opposite direction, thereby generating vibration.

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

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

the elastic supporting piece is easy to generate stress concentration in the vibration process, plastic deformation and polarization are caused, and the user experience and the use problem are influenced.

Disclosure of Invention

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

The present invention provides a linear vibration motor including: the driving assembly comprises a plurality of annular coils which are arranged at intervals along the vibration direction, and each annular coil is obliquely arranged along the vibration direction and is suitable for enabling two driving surfaces of the same annular coil to be staggered with each other; the magnetic assembly comprises a plurality of permanent magnets which are arranged on the inner side of the annular coil and are sequentially arranged 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; any one of the driving assembly or the magnetic assembly is a stator, and the other one is a rotor.

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

The linear vibration motor as described above, further preferably, the elastic member includes two connecting arms and three elastic cantilevers connected in an S-shape, the connecting arms are provided with arc-shaped gaps, and two sides of the arc-shaped gaps are respectively connected to the two elastic cantilevers.

The linear vibration motor as described above, further preferably, the driving assembly further includes a coil support, the coil support is disposed between the magnetic assembly and the housing, and an outer surface of the coil support is provided with an inclined guide groove, and the guide groove is 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 supporting bottom plate which can be relatively engaged with each other, and two bending portions are respectively provided at two end portions of the supporting bottom plate, and the bending portions are adapted to be connected to the elastic member.

In the above linear vibration motor, it is further preferable that a positioning boss is further provided on the bottom surface of the coil support, a positioning through hole is provided on the support base plate, and the positioning boss is adapted to the positioning through hole.

In the linear vibration motor, it is further preferable that 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 the first detection through holes correspond to the second detection through holes in position.

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

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

In the linear vibration motor described above, it is further preferable that the number of the permanent magnets is at least one less than the number of the annular 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 a vibration direction, and each annular coil is obliquely arranged along the vibration direction and is suitable for enabling two driving surfaces of the same annular coil to be staggered with each other; the magnetic assembly comprises a plurality of permanent magnets which are arranged on the inner side of the annular coil and are sequentially arranged 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; any one of the driving assembly or the magnetic assembly is a stator, and the other one is a rotor. The length of the annular coil in the vibration direction is increased, that is, the distribution area of the conductor for cutting the magnetic induction wire in the vibration direction is increased, and therefore the area range capable of providing the driving force is also increased 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, the position change between the magnetic field and the annular coil is relatively small along with the vibration of the permanent magnet, and the number change of the coils for cutting the magnetic induction lines to provide the driving force is 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 used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

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

fig. 2 is a schematic sectional view of the linear vibration motor of fig. 1;

FIG. 3 is a schematic view showing a structure of an elastic body in the linear vibration motor;

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

FIG. 5 is another structural view of an elastic body of the linear vibration motor;

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

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

Description of reference numerals:

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

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular 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 otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the terms in the present invention can be understood in a specific case to those skilled in the art.

In order to solve the problem that the driving force is too fast to be attenuated along with the displacement change of the vibrator 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 in this embodiment includes a driving assembly and a magnetic assembly, where the driving assembly includes a plurality of annular coils 1 arranged at intervals along a vibration direction, each annular coil 1 is arranged obliquely along the vibration direction, and is adapted to make two driving surfaces of the same annular coil 1 staggered with each other, and the energization 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 in sequence along the vibration direction, the magnetizing directions of the two adjacent permanent magnets 2 are opposite, and two magnetic poles of each permanent magnet 2 correspond to the driving surfaces of the two adjacent annular coils 1 respectively. In practical application, according to design requirements, either one of the driving assembly or the magnetic assembly can be fixedly arranged to serve as a stator, while the other one is movably arranged relatively to serve as a vibrator, and the stator and the vibrator are driven by acting force and reacting force to generate relative displacement. In this embodiment, as shown in fig. 2, it is preferable that the driving unit is a stator, the toroidal coil 1 is fixedly installed, the driving surfaces are an upper surface and a lower surface, respectively, the magnetic unit is a vibrator, and the permanent magnet 2 is magnetized in an up-and-down direction.

By virtue of the above structure, the length of the toroidal coil 1 in the vibration direction is increased, that is, the distribution area of the conductor for cutting the magnetic induction wire in the vibration direction is increased, and the area range in which the driving force can be provided in the driving direction is correspondingly increased. Meanwhile, compared with the horizontal relative magnetization of the permanent magnet 2, the up-and-down magnetization of the permanent magnet 2 enables the magnetic field in the magnetic assembly to be distributed on the upper surface and the lower surface of the permanent magnet 2 in a concentrated manner, and 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 lines is relatively small. By combining the two methods, 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 explosion structure diagram and a cross-sectional structure diagram of the linear vibration motor in 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, and 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 support 3 for winding the plurality of annular coils 1, specifically, as shown in fig. 7, the coil support 3 is a rectangular parallelepiped shell structure with two open ends, the periphery of the coil support 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 annular coils 1 can be wound at one time, and can also be wound in other modes such as series connection, parallel connection and the like. 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; still be equipped with a plurality of second on the coil bracket 3 and detect through-hole 33 and magnetism liquid injection through-hole, second detects through-hole 33 and is located the stupefied department of side for detect, magnetism liquid injection through-hole is located upper and lower surface department, is used for injecting magnetism liquid.

The magnetic assembly comprises a plurality of permanent magnets 2 and balancing weights 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 permanent magnets 2 arranged in sequence all have corresponding driving surfaces. In practical application, the number of the permanent magnets 2 and the number of the ring coils 1 can be set arbitrarily according to the amplitude requirement, and in this embodiment, specific description is given by taking 2

permanent magnets

2 and 3 ring coils 1 as examples. The both ends of permanent magnet 2 are located to balancing weight 4, and wherein, balancing weight 4 and permanent magnet 2's connected mode has the multiple, mainly adopts the mode of veneer to connect in this embodiment. The counterweight block 4 can be made of high-density metal materials such as a tungsten steel block, a nickel steel block or nickel-tungsten alloy and the like, so that the vibration force is increased, and the vibration of the electronic product is stronger.

As shown in fig. 6, the housing is a cuboid, and includes an upper housing 6 and a supporting bottom plate 7 that can be correspondingly fastened, wherein the upper housing 6 is a cuboid housing with an opening on one side, and a first detecting through hole 61 is formed thereon; the supporting bottom plate 7 is a flat plate, and is provided with a positioning through hole 71 and a bending part 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 edge 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, the positions of the positioning through holes correspond to the positions of the two positioning through holes 71 on the coil support 3, and the positioning through holes are suitable for being matched and installed with the positioning bosses 31 on the coil support 3; the two bending portions 72 are vertically arranged at two ends of the supporting bottom plate 7, are suitable for being connected with the elastic piece 5 and used for buffering the vibration of the magnetic assembly so as to avoid the magnetic assembly from impacting the end of the upper shell 6 when vibrating. In addition, a plurality of third detection through holes 73 are formed in the support 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 detection device is suitable for detecting the internal conditions of the housing.

As shown in fig. 2, 3, 4 and 5, the elastic members 5 are elastic pieces, and the number of the elastic pieces is two, and the elastic pieces are respectively disposed at two ends of the magnetic assembly and adapted to connect the magnetic assembly and the housing. The shell fragment is spacing to be fixed between magnetic component and shell, and the magnetic component can extrude the shell fragment of one end at the in-process of vibration, receives extruded shell fragment self to take place to warp in order to prevent magnetic component and shell collision at the vibration in-process, also can provide the elasticity restoring force in the opposite 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 each 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 further provided with a connecting surface 53, the two connecting surfaces 53 are used for being connected with the shell and the magnetic component respectively, and specifically, the two connecting surfaces 53 are connected with the bending portion 72 and the balancing weight 4 respectively. As shown in fig. 3 and 4, the connecting arms 51 can be preferably disposed on both sides of the elastic arm in the length direction thereof, depending on the height dimension of the housing, so as to more effectively utilize the height 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 connecting arms 51 may be provided at both sides in the width direction of the elastic arms. In the above structure, the arc-shaped notch in the elastic sheet enables the connecting arm 51 to be an excessive connecting arm 51 with a large curvature, thereby reducing the local stress of the elastic sheet and prolonging the fatigue life. In addition, the vibration frequency and mode of the linear vibration motor can be adjusted by adjusting the width, shape and plate thickness of the elastic arm or 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 toroidal coils 1 into an electronic equipment system.

In the structure, the permanent magnet 2 is vertically magnetized, magnetic lines of force generated by the upper surface and the lower surface of the permanent magnet respectively vertically pass through the annular coil 1 upwards and downwards, when the linear motor works, sinusoidal current is introduced into the annular coil 1, the period of the sinusoidal current is twice of the time for the permanent magnet 2 to move from the current position to the position of the adjacent permanent magnet 2, and the sinusoidal current in the adjacent annular coil 1 is adjusted simultaneously, so that the current of the two adjacent annular coils 1 is the same in size and opposite in direction. According to the left-hand rule of judging the stress direction of the electrified conductor in the magnetic field, the stress directions of the coils at the two ends of the permanent magnets 2 are the same and parallel to the vibration direction during electrification, 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 force and the reacting force, and drive the balancing weight 4 to move in a translation mode in the opposite direction. When the permanent magnet 2 moves to the position of the adjacent permanent magnet 2, the current direction in the annular coil 1 is completely reversed, the direction of the reaction force applied to the current position is still consistent with that of the current position, and the current continues to move under the reaction force until the current position is at the limit position. In the same way, the current direction in the annular coil 1 is changed, so that the corresponding relation between the current direction and the magnetic pole of the permanent magnet 2 is changed, the magnetic pole is driven by the driving force with the same magnitude and the 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 runs alternately to drive the micro vibration motor to vibrate.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A linear vibration motor, comprising:

the driving assembly comprises a plurality of annular coils which are arranged at intervals along the vibration direction, and each annular coil is obliquely arranged along the vibration direction and is suitable for enabling two driving surfaces of the same annular coil to be staggered with each other;

the magnetic assembly comprises a plurality of permanent magnets which are arranged on the inner side of the annular coil and are sequentially arranged 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;

any one of the driving assembly or the magnetic assembly is a stator, and the other one is a rotor.

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

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

4. The linear vibration motor of claim 2, wherein the driving assembly further comprises a coil support disposed between the magnet assembly and the housing, and an outer surface of the coil support is provided with an inclined guide groove 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 engaged with each other, and each of both ends of the supporting base plate is provided with a bent portion adapted to be connected to 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, a positioning through hole is provided on the support base plate, and the positioning boss is fitted with the positioning through hole.

7. The linear vibration motor of claim 5, wherein a plurality of first detection through holes are formed in the upper case, a plurality of second detection through holes are formed in the coil support, and the first detection through holes and the second detection through holes correspond in position.

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

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

10. A linear vibration motor according to claim 1, wherein the number of the permanent magnets is at least one less than the number of the annular coils.