Linear motor

Abstract

The invention provides a linear motor. The linear motor comprises a shell, an oscillator assembly accommodated in the shell, a stator assembly and a conductive damping piece, the stator assembly comprises a coil, the coil is arranged on one side of the vibrator assembly, and the damping piece is arranged on the other side of the vibrator assembly; the vibrator assembly comprises a magnet assembly, the magnet assembly comprises two side magnets and a center magnet, the magnetizing directions of the two adjacent side magnets are opposite, the center magnet comprises a magnetizing area and a non-magnetizing area, and the magnetizing direction of the magnetizing area is parallel to the vibration direction of the vibrator assembly, so that the magnet assembly forms a Halbach magnetic circuit. According to the invention, the problem that the vibration feedback requirement of the existing linear motor cannot meet the user requirement can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of linear motors, and more specifically, to a linear motor with a Halbach magnetic circuit. Background Art

[0002] In smart wearable devices such as VR (Virtual Reality) and AR (Augmented Reality), linear motors are usually used as their vibration feedback units. With the improvement of the functions of current smart wearable devices, users have higher requirements for the vibration feedback of smart wearable devices. Ordinary linear motors cannot meet users' increasingly enhanced usage experience needs. Summary of the invention

[0003] In view of the above problems, an object of the present invention is to provide a linear motor to solve the problem that the vibration feedback requirements of the existing linear motors cannot meet the needs of users.

[0004] The present invention provides a linear motor, comprising a housing, a vibrator assembly contained in the housing, a stator assembly for driving the vibrator assembly to vibrate, and a conductive damping member; wherein:

[0005] The stator assembly includes a coil, the coil is arranged on one side of the vibrator assembly, and the damping member is arranged on the other side of the vibrator assembly;

[0006] The vibrator assembly includes a magnet assembly, and the magnet assembly includes two side magnets and a central magnet sandwiched between the two side magnets, wherein:

[0007] The magnetization directions of two adjacent side magnets are opposite and perpendicular to the vibration direction of the vibrator assembly. The center magnet includes a magnetized area and a non-magnetized area arranged perpendicular to the vibration direction of the vibrator assembly, and the magnetization direction of the magnetized area is parallel to the vibration direction of the vibrator assembly, so that the magnet assembly forms a Halbach magnetic circuit.

[0008] In addition, a preferred solution is that the vibration assembly further includes a mass block, wherein:

[0009] A through hole is arranged on the mass block, and the magnet assembly is embedded in the through hole.

[0010] In addition, a preferred solution is that a damping member receiving groove is provided on the upper side of the mass block, and the damping member is at least partially located in the damping member receiving groove and on the upper side of the magnet assembly, and is fixed to the upper end of the shell.

[0011] In addition, a preferred solution is that a coil accommodating cavity is provided on the lower side of the mass block, and the coil is at least partially located in the coil accommodating cavity and on the lower side of the magnet assembly, and is fixed to the lower end of the shell.

[0012] In addition, a preferred solution is that the magnetized area is located at a portion close to the damping element and away from the coil, and the non-magnetized area is located at a portion close to the coil and away from the damping element.

[0013] In addition, a preferred solution is that the magnetized area is located at a portion close to the coil and away from the damping element, and the non-magnetized area is located at a portion close to the damping element and away from the coil.

[0014] In addition, a preferred solution is that it further includes two spring sheets, which are respectively located on both sides of the mass block, one end of the spring sheet is fixed to the mass block, and the other end is fixed to the shell.

[0015] In addition, a preferred solution is that a stopper is provided at a fixing position between the spring sheet, the mass block and the housing.

[0016] In addition, a preferred solution is that the damping element is a copper sheet.

[0017] In addition, a preferred solution is that the housing includes an upper cover, a middle frame and a lower shell, and the stator assembly, the vibrator assembly and the damping member are accommodated in a receiving cavity formed by the upper cover, the middle frame and the lower shell; wherein,

[0018] The damping member is fixed to the upper cover, the spring sheet is fixed to the middle frame, and the coil is fixed to the lower shell.

[0019] It can be seen from the above technical solutions that the linear motor provided by the present invention can achieve the following beneficial effects compared with the prior art:

[0020] 1) The present invention adopts a magnet assembly (the magnet assembly includes two side magnets and one center magnet) combined with a single coil structure. The effective utilization rate of this structure is much higher than the existing two magnets combined with a single coil structure. This structure can effectively adjust the strength of the magnetic surface and provide the required damping force or driving force for the product;

[0021] 2) The magnet assembly structure of the present invention can solve the limitation problem that traditional single magnets cannot be processed due to their small thickness. The central magnet in the magnet assembly includes a magnetized area and a non-magnetized area. The central magnet can adjust the size of the magnetized area and the non-magnetized area while satisfying the strength of the magnet itself to compensate for the problem of insufficient damping force or driving force required by the product.

[0022] In order to achieve the above and related purposes, one or more aspects of the present invention include the features that will be described in detail later. The following description and the accompanying drawings describe some exemplary aspects of the present invention in detail. However, these aspects indicate only some of the various ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all these aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other objects and results of the present invention will become more apparent and easy to understand. In the accompanying drawings:

[0024] Figure 1 is a schematic diagram of the decomposed structure of a linear motor according to an embodiment of the present invention;

[0025] Figure 2 is a cross-sectional view of a linear motor according to an embodiment of the present invention;

[0026] Figure 3 , Figure 4 They are respectively schematic diagrams of magnetization circuits according to embodiments of the present invention.

[0027] The figure marks include: 1, upper cover, 2, damping member, 3, mass block, 31, through hole, 32, coil accommodating chamber, 4, magnet assembly, 41, center magnet, 42, first side magnet, 43, second side magnet, 51, first stop block, 52, second stop block, 61, first spring piece, 62, second spring piece, 7, middle frame, 71, first middle frame, 72, second middle frame, 8, coil, 9, FPCB, 10, lower shell.

[0028] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0029] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details. In other examples, for ease of describing one or more embodiments, known structures and devices are shown in the form of block diagrams.

[0030] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] In order to solve the aforementioned problem that the vibration feedback requirements of the existing linear motors cannot meet the needs of users, the present invention proposes a linear motor.

[0032] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] The "mass block" used in the description of the following embodiments may also be referred to as a "counterweight block", both of which refer to a high-quality, high-density metal block fixed to a vibrating magnet assembly to enhance vibration balance.

[0034] In order to illustrate the structure of the linear motor provided by the present invention, Figures 1 to 4 The structure of the linear motor is exemplarily indicated from different angles. Specifically, Figure 1 The decomposition structure of a linear motor according to an embodiment of the present invention is shown; Figure 2 The cross-sectional structure of a linear motor according to an embodiment of the present invention is shown; Figure 3 , Figure 4 The magnetizing circuits according to the embodiments of the present invention are respectively shown.

[0035] like Figures 1 to 4 As shown together, the linear motor provided by the present invention includes a housing, a vibrator assembly housed in the housing, a stator assembly for driving the vibrator assembly to vibrate, and a conductive damping member 2; the stator assembly includes a coil, the coil 8 is arranged on one side of the vibrator assembly, and the damping member 2 is arranged on the other side of the vibrator assembly; the vibrator assembly includes a magnet assembly 4, the magnet assembly 4 includes two side magnets and a center magnet 41 sandwiched between the two side magnets, wherein the magnetization directions of the two adjacent side magnets are opposite and perpendicular to the vibration direction of the vibrator assembly. That is to say, if the vibration direction perpendicular to the vibrator assembly is defined as a first direction, the magnetization directions of the two adjacent side magnets are opposite and parallel to the first direction, the center magnet 41 includes a magnetized area and a non-magnetized area arranged along the vibration direction perpendicular to the vibrator assembly, and the magnetization direction of the magnetized area is parallel to the vibration direction, so that the magnet assembly forms a Halbach magnetic circuit.

[0036] In the present invention, the vibrator assembly of the linear motor reciprocates along the long axis direction, that is, the vibration direction of the vibrator assembly is parallel to the long axis direction. The vibration direction of the vibrator assembly can also be parallel to the short axis direction, or the vibration direction is parallel to the height direction, and the height direction is perpendicular to the long axis direction and the short axis direction. In the implementation of the present invention, there is no restriction on the vibration direction.

[0037] In one embodiment, the housing includes an upper cover 1, a middle frame 7 and a lower shell 10, the middle frame 7 includes a first middle frame 71 and a second middle frame 72, and the first middle frame 71 and the second middle frame 72 are connected end to end to form the middle frame 7. The stator assembly, the vibrator assembly and the damping member 2 are accommodated in a receiving cavity formed by the upper cover 1, the middle frame 7 and the lower shell 10; Figures 1 to 4 In the illustrated embodiment, the shell adopts a rectangular parallelepiped structure. In specific applications, the specific structure of the shell can also be set to other shapes, such as a cylinder, etc. according to actual needs. The specific status of the shell is not specifically limited here.

[0038] The damping member 2 is fixed to the upper cover 1, the stator assembly is fixed to the lower shell 10, and the vibrator assembly is located between the damping member 1 and the stator assembly. The stator assembly is used to provide vibration drive for the vibrator assembly, and the damping member 2 is used to provide electromagnetic damping for the vibrator assembly. The vibrator assembly vibrates linearly in the shell under the joint action of the stator assembly and the electromagnetic damping member, thereby providing vibration sensation for the electronic device.

[0039] The stator assembly includes a coil 8 and an FPCB9. The coil 8 is annular and is fixed to the lower shell 10 in an axial direction perpendicular to the vibration direction. The coil 8 and the damping member 2 are arranged on both sides of the vibrator assembly along a first direction perpendicular to the vibration direction of the vibrator assembly 20. The FPCB9 is electrically connected to the coil 8, and the coil 8 is connected to an external circuit through the FPCB9.

[0040] In one embodiment, the vibrator assembly includes a magnet assembly 4 and a mass block 3, wherein the magnet assembly 4 includes two adjacent side magnets (a first side magnet 42 and a second side magnet 43) and a center magnet 41, and the magnetization directions of the first side magnet 42 and the second side magnet 43 are opposite and parallel to the first direction, forming a closed magnetic circuit. The center magnet 41 includes a magnetized area and an unmagnetized area, and the magnetization direction of the magnetized area is parallel to the vibration direction, and the polarity of the end portions of the center magnet 41 and the adjacent first side magnet 42 and second side magnet 43 that are close to each other is the same. This structure of the magnet assembly 4 has a large driving force and a relatively high magnetic circuit utilization rate, which can effectively improve product performance requirements.

[0041] exist Figure 3In the illustrated embodiment, the dotted line on the center magnet 41 is the boundary line between the magnetized area and the non-magnetized area, the upper end is the magnetized area, and the lower end is the non-magnetized area; that is, the magnetized area of ​​the center magnet 41 is located near the damping element, and the part away from the damping element is the non-magnetized area (that is, the magnetized area is located near the damping element and away from the coil, and the non-magnetized area is near the coil and away from the damping element). This magnetization design is used in the case where the driving force of the magnet assembly is excessive and the damping is insufficient. By adopting this magnetization method, the insufficient damping force can be compensated.

[0042] exist Figure 4 In the illustrated embodiment, the dotted line on the center magnet 41 is the boundary between the magnetized area and the non-magnetized area, the lower end is the magnetized area, and the upper end is the non-magnetized area; that is, the magnetized area of ​​the center magnet 41 is located at the part far away from the damping element, and the part close to the damping element is the non-magnetized area (the magnetized area is located at the part close to the coil and far away from the damping element, and the non-magnetized area is close to the damping element and far away from the coil). This magnetization design is applied to the situation where the driving force of the magnet assembly is insufficient and the damping is excessive. By adopting this magnetization method, the situation of insufficient driving force can be compensated.

[0043] exist Figure 3 and Figure 4 In the embodiment shown, the polarities of the central magnet 41 and the adjacent first side magnets 42 and second side magnets 43 that are close to each other are the same. Figure 3 As shown, the magnetic poles of the first side magnet 42 and the second side magnet 43 are in opposite directions. The upper end of the first side magnet 42 is an S pole and the lower end is an N pole, while the upper end of the second side magnet 43 is an N pole and the lower end is an S pole. The magnetic pole close to the S pole of the first side magnet in the magnetizing area of ​​the center magnet 41 is an S pole, and the magnetic pole close to the N pole of the second side magnet in the magnetizing area of ​​the center magnet 41 is an N pole.

[0044] like Figure 4 As shown, the magnetic poles of the first side magnet 42 and the second side magnet 43 are in opposite directions. The upper end of the first side magnet 42 is an S pole and the lower end is an N pole, while the upper end of the second side magnet 43 is an N pole and the lower end is an S pole. The magnetic pole close to the N pole of the first side magnet in the magnetizing area of ​​the center magnet 41 is an N pole, and the magnetic pole close to the S pole of the second side magnet in the magnetizing area of ​​the center magnet 41 is an S pole.

[0045] In the present invention, the mass block 3 can improve the mass of the vibrator assembly, so that the vibrator assembly can provide a greater vibration sensation at a lower displacement, thereby reducing the risk of failure of the linear vibration motor and improving the reliability of the linear vibration motor. A through hole 31 is provided on the mass block 3, and the magnet assembly 4 is embedded in the through hole 31.

[0046] In one embodiment, a damping member receiving groove is provided on the upper side of the mass block 3, and the damping member 2 is at least partially located in the damping member receiving groove on the upper side of the magnet assembly 4 and fixed to the upper end of the shell (upper cover 1).

[0047] In one embodiment, a coil accommodating cavity 32 is provided at the lower side of the mass block 3, and the coil 8 is at least partially located in the coil accommodating cavity 32 at the lower side of the magnet assembly 4 and fixed to the lower end of the shell (lower shell 10).

[0048] In the embodiment of the present invention, the coil 8 combines with the Lorentz force generated by the Halbach magnetic circuit to drive the mass block 3 to reciprocate. The single Halbach magnetic circuit structure combined with the single coil structure of the present invention can effectively adjust the strength of the magnetic force and provide the required damping force or driving force for the product.

[0049] In the embodiment of the present invention, there are two springs, namely, a first spring 61 and a second spring 62. The two springs (the first spring 61 and the second spring 62) are respectively located on both sides of the mass block 3, one end of each spring is fixed to the mass block 3, and the other end is fixed to the middle frame 7 of the shell. The spring is a V-shaped spring, which is used to provide resilience for the vibrator assembly. The two springs are mirror-imaged on both sides of the mass block 3.

[0050] In addition, a stopper is provided at the fixing position of the spring sheet, the mass block 3 and the housing (specifically the middle frame 7), wherein a first stopper 51 is provided at the part of the first spring sheet 61 fixed to the mass block 3, the first spring sheet 61 is fixed to one side of the mass block 3 through the first stopper 51, and the second spring sheet 62 is fixed to the other side of the mass block 3 through the second stopper 52. The stopper not only plays a role in strengthening the fixing of the spring sheet, the mass block 3 and the middle frame 7, but also can reduce the noise generated by the vibrator assembly during vibration.

[0051] In addition, in the present invention, the damping member 2 is a copper sheet. The copper sheet is in the magnetic field formed by the magnet assembly. Since the magnet assembly follows the vibration of the vibrator assembly, the magnetic flux lines penetrating the copper sheet change alternately to generate a larger electromagnetic damping, so as to ensure the electromagnetic damping of the damping member 2, thereby improving the vibration consistency of the linear vibration motor.

[0052] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A linear motor, characterized in that: It comprises a shell, a vibrator assembly contained in the shell, a stator assembly for driving the vibrator assembly to vibrate, and a conductive damping member; wherein, The stator assembly includes a coil, the coil is arranged on one side of the vibrator assembly, and the damping member is arranged on the other side of the vibrator assembly; The vibrator assembly includes a magnet assembly, and the magnet assembly includes two side magnets and a central magnet sandwiched between the two side magnets, wherein: The magnetization directions of two adjacent side magnets are opposite and perpendicular to the vibration direction of the vibrator assembly. The center magnet includes a magnetized area and a non-magnetized area arranged perpendicular to the vibration direction of the vibrator assembly, and the magnetization direction of the magnetized area is parallel to the vibration direction of the vibrator assembly, so that the magnet assembly forms a Halbach magnetic circuit.

2. The linear motor according to claim 1, characterized in that: The vibrator assembly also includes a mass block, wherein: A through hole is arranged on the mass block, and the magnet assembly is embedded in the through hole.

3. The linear motor according to claim 2, characterized in that: A damping member accommodating groove is arranged on the upper side of the mass block, and the damping member is at least partially located in the damping member accommodating groove and on the upper side of the magnet assembly, and is fixed to the upper end of the shell.

4. The linear motor according to claim 2, characterized in that: A coil accommodating cavity is provided at the lower side of the mass block, and the coil is at least partially located in the coil accommodating cavity and at the lower side of the magnet assembly, and is fixed to the lower end of the shell.

5. The linear motor according to claim 1, characterized in that: The magnetized area is located at a portion close to the damping element and away from the coil, and the non-magnetized area is located at a portion close to the coil and away from the damping element.

6. The linear motor according to claim 1, characterized in that: The magnetized area is located at a portion close to the coil and away from the damping element, and the non-magnetized area is located at a portion close to the damping element and away from the coil.

7. The linear motor according to claim 2, characterized in that: It also includes two spring sheets, which are respectively located on both sides of the mass block, one end of the spring sheet is fixed to the mass block, and the other end is fixed to the shell.

8. The linear motor according to claim 7, characterized in that: A stopper is arranged at a fixing position between the spring piece, the mass block and the shell.

9. The linear motor according to any one of claims 1 to 8, characterized in that: The damping member is a copper sheet.

10. The linear motor according to claim 7, characterized in that: The housing comprises an upper cover, a middle frame and a lower shell, and the stator assembly, the vibrator assembly and the damping member are accommodated in a receiving cavity formed by the upper cover, the middle frame and the lower shell; wherein, The damping member is fixed to the upper cover, the spring sheet is fixed to the middle frame, and the coil is fixed to the lower shell.

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