Linear motor

Abstract

The present invention provides a linear motor, comprising a housing having an accommodating cavity, a vibration unit disposed in the accommodating cavity, a driving unit, and elastic members disposed at two sides of the vibration unit. The vibration unit comprises a mass block, and a mover fixed to the mass block. The driving unit is one of a coil and a magnetic steel assembly, and the mover is the other of a coil and the magnetic steel assembly. Damping foam is connected between the mass block and the elastic members, the damping foam comprising local fusing points, and the local fusing points being fused by means of heating, so that the damping foam is bonded to the mass block and / or the elastic members. The linear motor of the present invention heats the damping foam by means of fixed-point heating, and bonding of the damping foam to the elastic members and / or the mass block is achieved by relying on the adhesion of the melted damping foam, replacing foam gluing in the related art. This saves space in a Z direction, and effectively prevents glue from overflowing towards two sides onto other parts and affecting an assembly process of the linear motor, thereby improving the vibration performance of the linear motor.

Description

linear motor Technical Field

[0001] The present invention relates to the field of electroacoustic conversion, and in particular to a linear motor. Background Art

[0002] With the advent of the mobile internet era, the number of smart mobile devices continues to rise. Among these devices, mobile phones are undoubtedly the most common and portable smart mobile device. Vibration has become a fundamental function in smart mobile devices, and as a result, linear motors with vibration functions are now widely used in smart mobile devices.

[0003] The linear motor of the related technology includes a shell and a vibration unit accommodated in the shell, an elastic part that suspends the vibration unit in the shell, and a driving unit that drives the vibration unit to vibrate. The vibration unit includes a mass block and a mover fixed on the mass block. When the linear motor vibrates, appropriate damping is provided between the mass block and the elastic part by filling foam, and the edges of the junction between the foam and the elastic part and / or the mass block are glued and fixed to prevent the foam from falling off during vibration.

[0004] However, the state of the foam glue in the related art is affected by the assembly level, and it is easy for the glue to be too high, thereby causing Z-axis spatial interference and affecting the vibration performance of the linear motor.

[0005] Therefore, it is necessary to provide a new linear motor to solve the above technical problems. Technical issues

[0006] An object of the present invention is to provide a linear motor that saves Z-direction space and has good vibration performance. Technical Solutions

[0007] In order to achieve the above-mentioned purpose, the present invention provides a linear motor, which includes a shell having a receiving cavity, a vibration unit placed in the receiving cavity, a driving unit for driving the vibration unit to vibrate, and an elastic member that suspends the vibration unit in the receiving cavity, the shell includes an upper cover and a lower cover, the vibration unit includes a mass block and a mover fixed to the mass block, the driving unit is one of the coil and the magnetic steel assembly, the mover is the other of the coil and the magnetic steel assembly, a foam damper is connected between the mass block and the elastic member, the foam damper includes a local melting point, and the local melting point is melted by heating so that the foam damper is bonded to the mass block and / or the elastic member.

[0008] Preferably, the heating method of the local melting point is laser thermal energy.

[0009] Preferably, the elastic member includes two elastic arms located on both sides of the vibration direction of the vibration unit, each of the elastic arms includes a first fixing part fixed to the shell, a second fixing part fixed to the side of the mass block, and a connecting arm connecting the first fixing part and the second fixing part, and the foam damping is fixed to the connecting arm; the elastic member also includes a cantilever connecting the two second fixing parts, the cantilever is attached and fixed to the bottom surface of the mass block and is spaced apart from the lower cover.

[0010] Preferably, the mass block includes a planar portion which is arranged parallel to and spaced apart from the lower cover and has a hollow positioning groove, and an adhesive portion which protrudes from the outer end of the planar portion in a direction away from the lower cover; the mover is accommodated in the positioning groove; and the foam damper is fixed to the adhesive portion.

[0011] Preferably, two weight blocks perpendicular to both sides of the vibration direction are fixed on the top surface of the mass block; a support plate surrounded by the cantilever is fixed on the bottom surface of the mass block, the mover is the coil, and the coil is fixed to the support plate.

[0012] Preferably, the mover also includes a circuit board electrically connected to the coil, the circuit board including a first part fixed to the bottom surface of the mass block, a second part extending from the first part and fixed to the side of the mass block, a third part located outside the shell and connected to the external circuit, and a deformation part connecting the second part and the third part and capable of deforming in the vibration direction; the cantilever includes a notch portion, the first part passes through the notch portion and is spaced apart from the cantilever, and the coil lead of the coil is electrically connected to the first part.

[0013] Preferably, the support sheet includes a hollow groove, and a raised portion is provided at the center of the lower cover, which protrudes toward the drive unit and supports the drive unit, and the raised portion passes through the groove and the positioning slot;

[0014] The driving unit is the magnetic steel assembly, which is fixed to the protruding portion and spaced apart from the mover.

[0015] Preferably, a sound outlet is provided on one side of the upper cover, and the linear motor further comprises a basin fixed to the housing, a vibration system fixed to the basin, and a magnetic circuit system for driving the vibration system to vibrate, wherein the magnetic circuit system comprises a lower clamping plate fixed to the raised portion, a main magnetic assembly placed on the lower clamping plate, and a secondary magnetic assembly arranged around the main magnetic assembly to form a magnetic gap;

[0016] The magnetic circuit system serves as the magnetic steel component; the coil includes a hollow winding hole, and the winding hole is arranged opposite to the magnetic gap.

[0017] Preferably, the main magnetic assembly includes a first main magnetic steel placed on the lower clamping plate, a main pole core placed on the first main magnetic steel, and a second main magnetic steel placed on the main pole core. The auxiliary magnetic assembly includes a secondary pole core fixed to the basin frame and a plurality of secondary magnetic steels attached and fixed to the secondary pole core. The secondary magnetic steels are spaced apart from the coil.

[0018] Preferably, the vibration system includes a diaphragm fixed to the basin frame, a voice coil inserted in the magnetic gap and driving the diaphragm to vibrate, a frame connected to the diaphragm, and a flexible member fixed to the basin frame and spaced apart from the diaphragm and the mass block;

[0019] The frame includes a main body attached to the diaphragm, a first support arm extending along the outer periphery of the main body in a direction away from the diaphragm, and a second support arm extending along the inner periphery of the main body in a direction away from the diaphragm, the flexible member is connected between the first support arm and the basin frame, and the voice coil is fixed to the second support arm;

[0020] A lead connecting portion extends from the inner end of the flexible member toward the main body. The lead connecting portion is fixed to a side of the main body away from the diaphragm. A voice coil lead of the voice coil is connected to the lead connecting portion. Beneficial effects

[0021] Compared with the related art, the linear motor of the present invention sets a local melting point on the foam damper, heats the local melting point with laser thermal energy, and relies on the viscosity of the foam damper after melting to achieve bonding between the foam damper and the mass block and / or the foam damper and the elastic part, replacing the foam gluing in the related art, saving Z-direction space, and effectively preventing glue from overflowing to both sides to other parts and affecting the assembly process of the linear motor, thereby improving the vibration performance of the linear motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0023] FIG1 is a perspective view of a first linear motor provided by the present invention without a driving unit and an upper cover;

[0024] FIG2 is a diagram illustrating the assembly of a mass block, a coil, a support plate, a circuit board, and an elastic member in a first linear motor provided by the present invention;

[0025] FIG3 is an exploded perspective view of the first linear motor provided by the present invention;

[0026] FIG4 is an exploded perspective view of the second linear motor provided by the present invention;

[0027] FIG5 is a perspective view of a second linear motor provided by the present invention;

[0028] FIG6 is a cross-sectional view along line AA in FIG5 ;

[0029] Figure: linear motor 100, vibration direction X, housing 10, receiving chamber 10a, upper cover 11, sound outlet 11a, lower cover 12, raised portion 12a, mass 21, flat portion 211, positioning groove 212, bonding portion 213, coil 22, coil lead 221, winding hole 222, support plate 23, groove 231, weight 24, circuit board 25, first portion 251, second portion 252, third portion 253, deformation portion 254, magnetic steel assembly 31, magnetic steel 311, pole core 312, elastic member 40, elastic arm 41, first fixing portion 411, second fixing portion 41 2. Connecting arm 413, cantilever 42, notch 421, welding piece 43, foam damping 50, local melting point 51, basin frame 60, vibration system 70, diaphragm 71, voice coil 72, voice coil lead 721, skeleton 73, main body 731, glue groove 7311, first support arm 732, second support arm 733, flexible part 74, lead connecting part 741, electrical connecting part 742, magnetic circuit system 80, lower clamping plate 81, main magnetic assembly 82, first main magnet 821, main pole core 822, second main magnet 823, auxiliary magnetic assembly 83, auxiliary pole core 831, auxiliary magnet 832, magnetic gap 84. Modes for Carrying Out the Invention

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] 1-6 , the present invention provides a linear motor 100 , which includes a housing 10 having a receiving cavity 10 a , a vibration unit disposed within the receiving cavity 10 a , a driving unit for driving the vibration unit to vibrate, and elastic members 40 disposed on both sides of a vibration direction X of the vibration unit.

[0032] Among them, the shell 10 includes an upper cover 11 and a lower cover 12, the vibration unit includes a mass block 21 and a mover fixed to the mass block 21, the driving unit is one of the coil 22 and the magnetic steel assembly 31, and the mover is the other of the coil 22 and the magnetic steel assembly 31; when the driving unit is the coil 22, the mover is the magnetic steel assembly 31; when the driving unit is the magnetic steel assembly 31, the mover is the coil 22. The specific setting method is determined according to actual needs.

[0033] Referring to Figure 3 , the elastic member 40 includes two elastic arms 41 located on either side of the vibration unit in the vibration direction X. Each elastic arm 41 includes a first fixing portion 411 fixed to the housing 10, a second fixing portion 412 fixed to the side of the mass 21, and a connecting arm 413 connecting the first fixing portion 411 and the second fixing portion 412. Solder tabs 43 are fixed to the surfaces of the first fixing portion 411 and the second fixing portion 412, respectively, facing away from the housing 10 and the mass 21. The elastic member 40 also includes a cantilever 42 connecting the two second fixing portions 412. The cantilever 42 is attached to the bottom surface of the mass 21 and spaced apart from the lower cover 12. The cantilever 42 connects the two elastic arms 41 to form a unified elastic member 40 structure. This improves the consistency of the two elastic arms 41 and the symmetry of the vibration unit in the linear motor 100, reduces the degree of sway in the linear motor 100, and improves the vibration performance of the linear motor 100.

[0034] The mass block 21 includes a planar portion 211 that is arranged parallel to and spaced apart from the lower cover 12 and has a hollow positioning groove 212, and an adhesive portion 213 that protrudes from the outer end of the planar portion 211 in a direction away from the lower cover 12; the mover is accommodated and fixed in the positioning groove 212, which can make the mover more stably fixed to the mass block 21, while reducing the height space occupied by the mover.

[0035] Furthermore, a foam damper 50 is connected between the mass block 21 and the elastic member 40, and the foam damper 50 is clamped between the connecting arm 413 and the adhesive portion 213. The foam damper 50 includes local melting points 51, which are respectively located between the foam damper 50 and the connecting arm 413 and between the foam damper 50 and the adhesive portion 213. By heating and melting the local melting points 51, the foam damper 50 can be made sticky, thereby achieving a fixed connection between the foam damper 50 and the mass block 21 and / or the elastic member 40.

[0036] More preferably, laser thermal energy may be used to better locate and heat the local melting point 51 of the foam damper 50 , so as to achieve fixation of the foam damper 50 to the elastic member 40 and / or the mass block 21 .

[0037] Compared with the related art, the linear motor 100 of the present invention sets a local melting point 51 on the foam damper 50, melts the local melting point 51 by heating, and relies on the viscosity of the foam damper 50 after melting to achieve bonding between the foam damper 50 and the mass block 21 and / or the elastic member 40, replacing the foam gluing in the related art, saving Z-direction space, and effectively preventing glue from overflowing to both sides to other parts, thereby affecting the assembly process of the linear motor 100, so that the vibration performance of the linear motor 100 is better.

[0038] Specifically, referring to FIG1 , two weight blocks 24 perpendicular to the vibration direction X are fixed on the top surface of the mass block 21. The two weight blocks 24 are symmetrically arranged, which can increase the mass of the mass block 21 and improve the problems of light weight and unstable vibration of the mass block 21 caused by the hollow positioning groove 212.

[0039] A support plate 23, enclosed by a cantilever 42, is fixed to the bottom surface of the mass block 21. The support plate 23 includes a hollow groove 231. A raised portion 12a is provided in the center of the lower cover 12, protruding toward and supporting the drive unit. The raised portion 12a extends through the groove 231 and the positioning slot 212.

[0040] In order to better illustrate the specific structure of the linear motor 100 in the present invention, two specific embodiments will be explained below:

[0041] Specific implementation method 1

[0042] Please refer to Figures 1 to 3. In this embodiment, the driving unit is a magnetic steel assembly 31, and the mover includes a coil 22. The magnetic steel assembly 31 is fixed to the protrusion 12a and is spaced apart from the coil 22. The coil 22 is accommodated in the positioning groove 212 of the mass block 21 and is fixed to the support plate 23 to achieve the fixation of the coil 22 and the mass block 21.

[0043] In addition, please refer to Figure 2. The mover also includes a circuit board 25 electrically connected to the coil 22. The circuit board 25 includes a first part 251 fixed to the bottom surface of the mass block 21, a second part 252 extending from the first part 251 and fixed to the side of the mass block 21, a third part 253 located outside the housing 10 and connected to the external circuit, and a deformation part 254 connecting the second part 252 and the third part 253 and capable of deforming in the vibration direction X; the cantilever 42 includes a notch portion 421, the first part 251 passes through the notch portion 421 and is spaced apart from the cantilever 42, and the first part 251 is connected to the coil lead 221 of the coil 22 to introduce an electrical signal into the coil 22, thereby realizing independent control of the linear motor 100.

[0044] In this embodiment, the magnetic steel assembly 31 includes a magnetic steel 311 fixed to the protrusion 12a and a pole core 312 placed on the magnetic steel 311. There are two coils 22, located on both sides of the vibration direction X and symmetrically arranged on both sides of the protrusion 12a.

[0045] In this embodiment, the vibration principle of the linear motor 100 is as follows: the coil 22 is within the magnetic field range of the magnetic steel assembly 31, and interacts with each other to generate an electromagnetic field; at this time, by controlling the current direction of the coil 22, a mutual driving force with the magnetic steel assembly 31 can be achieved; the coil 22 is fixed to the mass block 21 and is suspended within the receiving cavity 10a together with the mass block 21 through the elastic member 40, serving as a vibration unit; the magnetic steel assembly 31 is spaced apart from the coil 22 and fixed to the raised portion 12a of the lower cover 12, serving as a fixed driving unit. Driven by the magnetic field, the coil 22 and the mass block 21 vibrate simultaneously, thereby driving the entire linear motor 100 to vibrate.

[0046] Specific implementation method 2

[0047] 4-6 , the linear motor 100 of this embodiment further includes a frame 60 fixed to the housing 10, a vibration system 70 fixed to the frame 60, and a magnetic circuit system 80 for driving the vibration system 70. The magnetic circuit system 80 includes a lower clamping plate 81 fixed to the raised portion 12 a, a main magnetic assembly 82 positioned on the lower clamping plate 81, and a secondary magnetic assembly 83 disposed around the main magnetic assembly 82 to form a magnetic gap 84.

[0048] In this embodiment, the driving unit is a magnetic steel assembly 31, and the magnetic circuit system 80 serves as the magnetic steel assembly 31; the mover is a coil 22 fixed to the mass block 21, and the coil 22 includes a hollow winding hole 222, which is arranged opposite to the magnetic gap 84.

[0049] In addition, the mover further includes a circuit board 25 electrically connected to the coil 22 . The circuit board 25 is connected to the coil lead 221 of the coil 22 to introduce an electrical signal to the coil 22 , thereby realizing independent control of the linear motor 100 .

[0050] Furthermore, the upper cover 11 of this embodiment is also provided with a sound outlet 11a. The vibration system 70, the magnetic circuit system 80 and the basin frame 60 together constitute a sound-generating unit for sound production, and the sound is output to the outside through the sound outlet 11a, so that the linear motor 100 of this embodiment has a sound-generating function on the basis of the vibration function.

[0051] Specifically, the main magnetic assembly 82 includes a first main magnet 821 placed on the lower clamping plate 81, a main pole core 822 placed on the first main magnet 821, and a second main magnet 823 placed on the main pole core 822. The auxiliary magnetic assembly 83 includes an auxiliary pole core 831 fixed to the basin frame 60 and four auxiliary magnets 832 attached and fixed to the auxiliary pole core 831. The four auxiliary magnets 832 are spaced apart from the coil 22. The four auxiliary magnets 832 are symmetrical about the main magnetic assembly 82 in any direction, which can enhance the compactness and stability of the magnetic circuit system 80.

[0052] In this embodiment, the vibration system 70 includes a diaphragm 71 fixed to the frame 60, a voice coil 72 inserted in the magnetic gap 84 and driving the diaphragm 71 to vibrate, a frame 73 connected to the diaphragm 71, and a flexible member 74 fixed to the frame 60 and spaced apart from the diaphragm 71 and the mass 21.

[0053] Among them, the skeleton 73 includes a main body 731 attached to the diaphragm 71, a first support arm 732 extending along the outer periphery of the main body 731 in a direction away from the diaphragm 71, and a second support arm 733 extending along the inner periphery of the main body 731 in a direction away from the diaphragm 71. The flexible part 74 is connected between the first support arm 732 and the basin frame 60, and the voice coil 72 is suspended in the magnetic gap 84 through the second support arm 733.

[0054] Furthermore, two symmetrically distributed glue grooves 7311 are provided on the main body 731 of the skeleton 73. The two glue grooves 7311 are located on both sides perpendicular to the vibration direction X. Of course, according to actual conditions, they can also be set on both sides of the vibration direction X. The two glue grooves 7311 can be filled with glue to achieve the fixation of the skeleton 73 and the diaphragm 71.

[0055] There are two flexible members 74, one located on either side of the vibration direction X. A lead connection portion 741 extends from the inner end of one of the flexible members 74 toward the main body 731. The lead connection portion 741 is fixed to the side of the main body 731 away from the diaphragm 71. The voice coil lead 721 of the voice coil 72 is connected to the lead connection portion 741. An electrical connection portion 742 extends outward from the outer end of the flexible member 74 for electrical connection to an external circuit.

[0056] The vibration principle of the linear motor 100 in this embodiment is as follows: the coil 22 is within the magnetic field of the magnetic circuit system 80, and the coils 22 interact with each other to generate an electromagnetic field. At this time, by controlling the direction of the current in the coil 22, a mutual driving force with the magnetic circuit system 80 can be achieved. The magnetic circuit system 80 is fixed to the housing 10 via the bracket 60, serving as a driving unit. The coil 22 and the mass 21 are elastically suspended within the receiving cavity 10a via the elastic member 40, serving as a vibration unit. In this way, the magnetic circuit system 80 can cause the coil 22 and the mass 21 to vibrate simultaneously, thereby driving the entire linear motor 100 to vibrate.

[0057] The above description is only an embodiment of the present invention. It should be pointed out that those skilled in the art can make improvements without departing from the creative concept of the present invention, but these improvements all fall within the scope of protection of the present invention.

Claims

1. A linear motor comprising a housing having a receiving cavity, a vibration unit disposed in the receiving cavity, a driving unit for driving the vibration unit to vibrate, and an elastic member suspending the vibration unit in the receiving cavity, wherein the housing comprises an upper cover and a lower cover, the vibration unit comprises a mass block and a mover fixed to the mass block, the driving unit is one of a coil and a magnetic steel assembly, the mover is the other of the coil and the magnetic steel assembly, a foam damper is connected between the mass block and the elastic member, and the motor is characterized in that: The foam damper includes a local melting point, and the local melting point is melted by heating, so that the foam damper is adhered to the mass block and / or the elastic member.

2. The linear motor according to claim 1, wherein The local melting point is heated by laser thermal energy.

3. The linear motor according to claim 1, wherein The elastic member includes two elastic arms located on both sides of the vibration direction of the vibration unit, each of the elastic arms includes a first fixing part fixed to the shell, a second fixing part fixed to the side of the mass block, and a connecting arm connecting the first fixing part and the second fixing part, and the foam damper is fixed to the connecting arm; the elastic member also includes a cantilever connecting the two second fixing parts, the cantilever is attached and fixed to the bottom surface of the mass block and spaced apart from the lower cover.

4. The linear motor according to claim 3, wherein: The mass block includes a planar portion which is arranged parallel to and spaced apart from the lower cover and has a hollow positioning groove, and an adhesive portion which protrudes from the outer end of the planar portion in a direction away from the lower cover; the mover is accommodated in the positioning groove; and the foam damper is fixed to the adhesive portion.

5. The linear motor according to claim 4, wherein: Two weight blocks perpendicular to the vibration direction are fixed on the top surface of the mass block; a support plate surrounded by the cantilever is fixed on the bottom surface of the mass block, the mover is the coil, and the coil is fixed to the support plate.

6. The linear motor according to claim 5, wherein: The mover also includes a circuit board electrically connected to the coil, the circuit board including a first part fixed to the bottom surface of the mass block, a second part extending from the first part and fixed to the side of the mass block, a third part located outside the shell and connected to the external circuit, and a deformation part connecting the second part and the third part and capable of deforming in the vibration direction; the cantilever includes a notch portion, the first part passes through the notch portion and is spaced apart from the cantilever, and the coil lead of the coil is electrically connected to the first part.

7. The linear motor according to claim 5, wherein: The support sheet includes a hollow groove, and a raised portion is provided at the center of the lower cover, which protrudes toward the drive unit and supports the drive unit, and the raised portion passes through the groove and the positioning slot; The driving unit is the magnetic steel assembly, which is fixed to the protruding portion and spaced apart from the mover.

8. The linear motor according to any one of claims 1 to 7, characterized in that: A sound outlet is provided on one side of the upper cover. The linear motor further comprises a basin fixed to the housing, a vibration system fixed to the basin, and a magnetic circuit system for driving the vibration system to vibrate. The magnetic circuit system comprises a lower clamping plate fixed to the raised portion, a main magnetic assembly placed on the lower clamping plate, and a secondary magnetic assembly arranged around the main magnetic assembly to form a magnetic gap. The magnetic circuit system serves as the magnetic steel component; the coil includes a hollow winding hole, and the winding hole is arranged opposite to the magnetic gap.

9. The linear motor according to claim 8, wherein: The main magnetic assembly includes a first main magnetic steel placed on the lower clamping plate, a main pole core placed on the first main magnetic steel, and a second main magnetic steel placed on the main pole core. The auxiliary magnetic assembly includes a secondary pole core fixed to the basin frame and a plurality of secondary magnetic steels attached and fixed to the secondary pole core. The secondary magnetic steels are spaced apart from the coil.

10. The linear motor according to claim 8, wherein The vibration system includes a diaphragm fixed to the basin frame, a voice coil inserted in the magnetic gap and driving the diaphragm to vibrate, a frame connected to the diaphragm, and a flexible member fixed to the basin frame and spaced apart from the diaphragm and the mass block; The skeleton includes a main body attached to the diaphragm, a first support arm extending along the outer periphery of the main body in a direction away from the diaphragm, and a second support arm extending along the inner periphery of the main body in a direction away from the diaphragm, the flexible member is connected between the first support arm and the basin frame, and the voice coil is fixed to the second support arm. A lead connecting portion extends from the inner end of the flexible member toward the main body. The lead connecting portion is fixed to a side of the main body away from the diaphragm. A voice coil lead of the voice coil is connected to the lead connecting portion.

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