Closed-loop magnetic circuit vibration motor

Abstract

The invention discloses a closed-loop magnetic circuit vibration motor, which is provided with a motor body, and comprises a stator part fixing seat, a rotor part and a suspension device, the stator part fixing seat comprises a coil assembly, a stator yoke and a flexible circuit board, and the coil assembly is connected with the stator part fixing seat; the stator yoke is connected with the stator part fixing seat and is arranged on one side of the coil assembly. The mover part is arranged on the other side of the coil assembly relative to the stator yoke and comprises a mover carrying seat and a magnet, and the mover carrying seat is connected with the stator part fixing seat through a suspension device; the plurality of magnets are connected with the rotor carrier, the plurality of magnets are arranged in the same direction, and the magnetic poles of the plurality of adjacent magnets are opposite; the rotor yoke is arranged on the side, away from the coil assembly, of the rotor carrier. The number of the stator yokes corresponds to the number of the magnets, the stator yokes in the stator yokes form stator yoke projection surfaces on the magnet surfaces of the corresponding magnets, and the area of the stator yoke projection surfaces is smaller than that of the corresponding magnet surfaces.

Description

Technical Field

[0001] This invention relates to the field of vibration motors, and in particular to vibration motors having a closed-loop magnetic circuit structure. Background Technology

[0002] With the development of touch devices, they have gradually replaced traditional buttons on portable devices, allowing for more space to be allocated to the screen and thus increasing the screen-to-body ratio. However, after buttons were completely replaced, the drawback of cold, hard screens that could not provide tactile feedback gradually became apparent. To improve the user experience, portable device manufacturers began to research how to use vibration motors to provide tactile feedback to users on touch devices.

[0003] Traditional vibration motors can be mainly divided into two categories: rotor motors and linear motors. Rotor motors generate vibration by rotating an asymmetrical cam; linear motors generate vibration by the reciprocating motion of a mover in a specific direction. Since linear motors do not require rotation, there is no start-up delay, allowing for more immediate and rapid vibration feedback. Furthermore, by controlling the current, the magnitude of the Lorentz force generated by the magnetic field can be controlled, resulting in a stronger vibration.

[0004] A linear motor is a type of motor that uses staggered magnetic poles arranged in a straight line to create an ambient magnetic field, and utilizes coils and the air gap between the coils and the magnetic poles to allow relative motion of the actuator. Since the Lorentz force is positively correlated with the strength of the ambient magnetic field, increasing the strength of the ambient magnetic field can effectively increase the vibration. Magnetic field strength is essentially a manifestation of magnetic flux density; increasing magnetic field strength is equivalent to increasing magnetic flux density. Generally, to increase magnetic flux density, magnets can be added; or local magnetic reluctance can be reduced to increase local magnetic flux density.

[0005] In pursuit of slimmer and lighter portable products, many manufacturers use conductive magnetic materials, known as yokes, to reduce the size of vibration motors and effectively utilize magnetic fields. This reduces local magnetic resistance, constricts magnetic lines of force to form a closed-loop magnetic circuit, and increases the strength of the ambient magnetic field. However, the yoke itself is also attracted by magnets, generating magnetic attraction, which can place an unnecessary burden on the suspension device that maintains the air gap.

[0006] In view of the limitations of the magnetic field strength of the vibration motor in the prior art due to the thinning of the product, and the disadvantage of increasing the burden on the suspension device by the yoke, the inventors of this case have been actively and continuously developing inventions that can improve the above problems. Summary of the Invention

[0007] The main objective of this invention is to reduce the suction force generated by the yoke, thereby reducing the burden on the suspension device.

[0008] Another objective of this invention is to find the most efficient closed-loop magnetic circuit vibration motor by adjusting the relative positions of the stator yoke and the magnet.

[0009] The closed-loop magnetic circuit vibration motor of the present invention has a motor body, including: a stator mounting base, a mover, and a suspension device. The stator mounting base includes: a coil assembly, a stator yoke, and a flexible circuit board, wherein the coil assembly is disposed inside the stator mounting base; the stator yoke is connected to the stator mounting base and disposed on one side of the coil assembly, and the stator yoke is made of conductive magnetic material; and the flexible circuit board is electrically connected to the coil assembly for supplying and regulating current to the coil assembly.

[0010] The mover portion is disposed on the other side of the coil group opposite to the stator yoke, and includes: a mover carrier and a magnet, wherein the mover carrier is connected to the stator fixed seat via the suspension device; the magnet connects to the mover carrier and generates a mover magnetic field, and the side of the magnet near the coil group forms a magnet surface; the mover yoke is disposed on the side of the mover carrier away from the coil group.

[0011] The suspension device includes: an elastic support assembly and a fixing assembly. One end of the elastic support assembly is connected to the mover carrier. The fixing assembly is fixedly connected to the other end of the elastic support assembly and the stator fixing seat, so that an air gap is formed between the mover and the coil assembly.

[0012] In a preferred embodiment of the present invention, the flexible circuit board provides current to the coil assembly, which, in conjunction with the moving part magnetic field generated by the magnet, forms an electromagnetic thrust, causing the moving part to displace. The stator yoke forms a stator yoke projection surface on the magnet surface of the corresponding magnet, and the area of ​​the stator yoke projection surface is smaller than the area of ​​the corresponding magnet surface.

[0013] In a preferred embodiment of the present invention, the projection surface of the stator yoke can be located in the middle of the magnet surface of the corresponding magnet, so as to reduce the attraction between the stator yoke and the magnet.

[0014] Preferably, the geometric center of the stator yoke projection surface overlaps with the geometric center of the magnet surface to reduce the attraction between the stator yoke and the magnet.

[0015] In a preferred embodiment of the present invention, there are multiple magnets arranged in the same direction, and the magnetic poles of adjacent magnets are opposite.

[0016] Preferably, the adjacent magnets do not come into direct contact with each other.

[0017] Preferably, the magnetization direction of the magnet is perpendicular to the magnet surface.

[0018] Preferably, the elastic support component can be a leaf spring.

[0019] In a preferred embodiment of the present invention, the flexible circuit board has an electrical control processing unit for receiving external signals and adjusting the magnitude and direction of the current. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of an approximately closed-loop magnetic circuit according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the stator yoke projection surface according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a simulation model for an embodiment of the present invention;

[0025] Figure 6 This is a line graph showing the magnetic attraction force and motor thrust relative to the stator yoke projection surface and the magnet surface in the simulation model of this invention.

[0026] Figure 7 This is a line graph showing the ratio of motor thrust to magnetic attraction force in the simulation model of this invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1: Stator mounting bracket;

[0029] 11: Coil group;

[0030] 12: Stator yoke;

[0031] 120: Projected surface of stator yoke;

[0032] 13: Flexible circuit board;

[0033] 2: Moving part;

[0034] 21: Motion carrier;

[0035] 22: Magnet;

[0036] 220: Magnet surface;

[0037] 2210: Magnetic field lines;

[0038] 221N: North pole of a magnet;

[0039] 221S: S pole of a magnet;

[0040] 23: Moving yoke;

[0041] 3: Suspension device;

[0042] 31: Elastic support component;

[0043] 32: Fixed components;

[0044] S: Spacing. Detailed Implementation

[0045] To facilitate understanding of the present invention, a detailed description of the invention is provided below with reference to the accompanying drawings and embodiments. The drawings show only a portion of the embodiments of the invention, not all of them. The invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any inventive effort are within the scope of protection of the present invention.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0047] Figures 1 to 7 This is a schematic diagram of an embodiment of the present invention, as shown below. Figure 1 As shown in the exploded perspective view of an embodiment of the present invention, the closed-loop magnetic circuit vibration motor of the present invention has a motor body, including: a stator mounting base 1, a mover 2, and a suspension device 3. The stator mounting base 1 includes: a coil assembly 11, a stator yoke 12, and a flexible circuit board 13, wherein the coil assembly 11 is disposed inside the stator mounting base 1; the stator yoke 12 is disposed on one side of the coil assembly 11 and connected to the stator mounting base 1, and the stator yoke 12 is made of conductive magnetic material; and the flexible circuit board 13 is electrically connected to the coil assembly 11 for supplying and regulating current to the coil assembly 11.

[0048] like Figure 1 as well as Figure 2 As shown in the schematic diagram of an embodiment of the present invention, the mover portion 2 is disposed on the other side of the coil group 11 opposite to the stator yoke 12, and includes: a mover carrier 21, a magnet 22, and a mover yoke 23. The mover carrier 21 is connected to the stator fixing seat 1 via the suspension device 3. The magnet 22 connects to the mover carrier 21 and generates a mover magnetic field. The mover yoke 23 is disposed on the side of the mover carrier 21 away from the coil group 11.

[0049] The suspension device 3 includes an elastic support component 31 and a fixing component 32. One end of the elastic support component 31 is connected to the mover carrier 21. The fixing component 32 is fixed to connect the other end of the elastic support component 31 to the stator fixing seat 1, maintaining the distance between the stator fixing seat 1 and the mover 2, so that an air gap is maintained between the mover 2 and the coil assembly 11.

[0050] In a preferred application, the flexible circuit board 13 provides current to the coil assembly 11, which, together with the moving magnetic field generated by the magnet 22, forms an electromagnetic thrust, causing the moving part 2 to displace.

[0051] In a preferred embodiment of the present invention, there are multiple magnets 22, which are arranged in the same direction and the magnetic poles of adjacent magnet surfaces 220 are opposite.

[0052] like Figure 3 A schematic diagram of an approximate closed-loop magnetic circuit according to an embodiment of the present invention and Figure 4 As shown in the schematic diagram of the stator yoke projection surface 120 in the embodiment of the present invention, the number of stator yokes 12 corresponds to the number of magnets 22, and the stator yoke projection surface 120 is formed on the surface of the magnets 22 corresponding to the stator yokes 12, and the area of ​​the stator yoke projection surface 120 is smaller than the area of ​​the corresponding magnet surface 220.

[0053] Specifically, the mover carrier 21 is suspended from the motor body by the elastic support assembly 31 and can swing freely. When current flows through the coil assembly 11, a Lorentz force is generated, but because the coil assembly 11 is fixed, the mover part 2 will be displaced due to the reaction force generated by the Lorentz force; and the flexible circuit board 13 can control the direction of the current to change the direction of displacement of the mover part 2.

[0054] Furthermore, such as Figure 3 As shown, the stator yoke 12 and the mover yoke 23 can constrict the magnetic field lines 2210 to increase the strength of the mover magnetic field, thereby enhancing the electromagnetic thrust generated by the coil assembly 11. The stator yoke 12 creates an approximately closed-loop magnetic circuit on the side of the mover portion 2 closest to the coil assembly 11; the mover yoke 23 creates a closed-loop magnetic circuit on the side of the mover portion 2 furthest from the coil assembly 11.

[0055] like Figure 4 As shown, the stator yoke projection surface 120 can be located in the center of the magnet surface 220 to reduce the magnetic attraction between the stator yoke 12 and the magnet 22.

[0056] Specifically, such as Figure 1 , Figure 4 as well as Figure 5The simulation model diagram of this invention is shown below. Taking a set of magnets 22 as an example, both the N pole 221N and the S pole 221S of the magnets have a stator yoke projection surface 120 projected onto the magnet surface 220. The adjacent sides of the N pole 221N and the S pole 221S of the magnets are the inner sides, and the opposite sides are the outer sides. The distance between the two stator yoke projection surfaces 120 is the spacing S. Furthermore, the other side of the magnet 22 opposite to the magnet surface 220 is connected to the mover yoke 23. Model 1 (DOE1) is a form where the magnet 22 is not paired with the stator yoke 12, and Model 6 (DOE6) is a form where the magnet surface 220 and the stator yoke projection surface 120 have the same width. Model 2 (DOE2) has the outer side of the stator yoke projection surface 120 aligned with the outer side of the magnet surface 220; Model 3 (DOE3) has the center of the two stator yoke projection surfaces 120 aligned with the center of the magnet surface 220; Model 4 (DOE4) has the inner sides of the two stator yoke projection surfaces 120 close to the inner side of the magnet surface 220, but the two stator yoke projection surfaces 120 are not in contact; Model 5 (DOE5) has the inner sides of the two stator yoke projection surfaces 120 touching. The spacing S between Models 2 to 5 is in the following order: Model 2 > Model 3 > Model 4 > Model 5 = 0.

[0057] like Figure 6 The graph shows the magnetic attraction force and motor thrust relative to the stator yoke projection surface 120 and the magnet surface 220. Under the above model conditions, Model 1 will not have magnetic attraction force because it does not have a stator yoke 12. Figure 6 As shown, the magnetic attraction forces of models 2 through 6 are in the following order: Model 6 > Model 5 > Model 2 > Model 4 > Model 3. Figure 7 The line graph showing the ratio of motor thrust to magnetic attraction force is shown. The ratios of models 2 to 5 are in the following order: Model 3 > Model 4 > Model 2 > Model 6 > Model 5.

[0058] In summary, under the same geometric conditions between the magnet surface 220 and the stator yoke projection surface 120, the maximum ratio of motor thrust to magnetic attraction can be obtained when the geometric center of the stator yoke projection surface 120 coincides with the geometric center of the magnet surface 220. Conversely, when the stator yoke projection surface 120 is tangent to the edge of the magnet surface 220 or crosses the magnetic pole junction, the ratio of motor thrust to magnetic attraction will be smaller. This means that the attraction between the magnet 22 and the stator yoke 12 is relatively large, and excessive magnetic attraction may cause excessive deformation of the suspension device 3 in the normal direction of the magnet surface 220 and affect the performance of the motor body.

[0059] Preferably, adjacent magnets 22 do not come into direct contact, so as to reduce weight while increasing the magnetic field coverage of magnets 22.

[0060] Preferably, the magnetization direction of magnet 22 is perpendicular to magnet surface 220.

[0061] Preferably, the elastic support component 31 can be a leaf spring.

[0062] In a preferred embodiment of the present invention, the flexible circuit board 13 has an electronic control processing unit (not shown) for receiving external signals and adjusting the magnitude and direction of the current in the coil group 11.

[0063] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various changes and modifications without departing from the inventive concept, and these all fall within the scope of protection of the present invention.

Claims

1. A closed-loop magnetic circuit vibration motor, comprising a motor body, characterized in that, include: A fixed base for the oscillator includes: A coil assembly is disposed inside the stator mounting base; A stator yoke, disposed on one side of the coil assembly, is made of a conductive magnetic material; and A flexible circuit board is electrically connected to the coil assembly; A moving part, disposed on the other side of the coil group opposite the stator yoke, includes: A movable carrier is connected to the stator fixing seat via a suspension device; A magnet is connected to the moving part carrier, and the magnet forms a magnet surface on one side of the magnet near the coil assembly; A mover yoke is disposed on the side of the mover carrier away from the stator fixing seat; and The suspension device includes: an elastic support assembly and a fixing assembly. One end of the elastic support assembly is connected to the mover carrier so that the mover part can move back and forth relative to the stator fixing seat through the elastic support assembly. The fixing assembly is fixedly connected to the other end of the elastic support assembly and the stator fixing seat, and forms an air gap between the mover part and the coil group. The flexible circuit board provides a current into the coil group, which, together with the moving magnetic field generated by the magnet, forms an electromagnetic thrust. Each of the stator yokes forms a stator yoke projection surface on one side of the corresponding magnet, and the area of ​​the stator yoke projection surface is smaller than the area of ​​the corresponding magnet surface.

2. The closed-loop magnetic circuit vibration motor according to claim 1, characterized in that, The stator yoke projection surface is located in the middle of the corresponding magnet surface.

3. The closed-loop magnetic circuit vibration motor according to claim 2, characterized in that, The geometric center of the stator yoke projection surface overlaps with the geometric center of the magnet surface to reduce the magnetic attraction of the magnet on the stator yoke.

4. The closed-loop magnetic circuit vibration motor according to any one of claims 1 to 3, characterized in that, There are multiple magnets, which are arranged in the same direction and the magnetic poles of adjacent magnet faces are opposite.

5. The closed-loop magnetic circuit vibration motor according to claim 4, characterized in that, The adjacent magnets are not in direct contact with each other.

6. The closed-loop magnetic circuit vibration motor according to claim 5, characterized in that, The magnetization direction of the magnet is perpendicular to the surface of the magnet.

7. The closed-loop magnetic circuit vibration motor according to claim 5, characterized in that, The elastic support component is a leaf spring.

8. The closed-loop magnetic circuit vibration motor according to claim 5, characterized in that, The flexible circuit board has an electronic control processing unit for receiving external signals and adjusting the magnitude and direction of the current.

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