Assembly process of linear motor driving structure

Abstract

The invention relates to the technical field of linear motors, in particular to a linear motor driving structure, which comprises the following steps of: an M-shaped yoke process: stamping by adopting a high-precision progressive die, and forming to obtain an M-shaped yoke; a buckle or a groove is designed at the edge of the M-shaped yoke and is matched with the inner wall of the penetrating opening of the vibrator base body; magnetic steel is pre-fixed, and positioning is assisted through magnetic field adsorption; the middle yoke and the coil framework are integrated through laser spot welding; the miniature linear vibration motor vibrator structure with high magnetic efficiency, low loss and fast response is constructed through an M-shaped yoke closed magnetic circuit design, double-magnetic-steel vertical layered arrangement, double-Yoke magnetic field coupling and an ultrathin precision manufacturing process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of linear motor, in particular to an assembly process of linear motor driving structure. BACKGROUND

[0002] The driving structure of the linear motor is mainly based on the principle of electromagnetic force, and the linear motion is realized by the interaction of the magnetic field generated by the current and the magnetic pole.

[0003] The existing linear motor driving structure has the following shortcomings:

[0004] 1. Complexity of structure and space occupation problem

[0005] Many parts lead to difficult assembly: the traditional linear motor adopts a cuboid structure, and the number of internal mover assemblies (such as elastic members, magnetic steel, and vibrators) is large, the assembly steps are complicated, the tolerance accumulation easily leads to performance deviation, and the production cost is high.

[0006] Low volume and space utilization: for example, the transverse linear motor (X-axis) needs to occupy a large horizontal space, which affects the layout of the mobile phone battery or other components; although the cylindrical vibrator design can optimize the center of gravity, it still needs a complex assembly process.

[0007] External filter circuit occupies the mainboard area: the traditional scheme needs to design a filter circuit on the mainboard to reduce electromagnetic interference, but it occupies the layout space of the compact device, which is not conducive to miniaturization.

[0008] 2. Insufficient vibration performance and response speed

[0009] Inherent defects of rotor motor:

[0010] Response delay: the rotor motor relies on the rotation of the eccentric block to generate vibration, and there is inertia delay (>20ms) in starting and stopping, and the vibration is loose and sluggish 91013.

[0011] Vibration direction is uncontrollable: the rotary structure leads to non-directional vibration, making it difficult to achieve delicate haptic feedback.

[0012] Single-vibrator structure vibration mode is single: the existing linear motor mostly adopts single-vibrator design, which can only realize single-direction vibration and cannot superimpose multi-mode haptic effect (such as simultaneously simulating vibration in different directions or intensity).

[0013] Insufficient driving force: the traditional electromagnetic drive relies on the ampere force, and the driving force is small, which is difficult to meet the high vibration demand; some designs use foam damping members to further weaken the driving force.

[0014] 3. Anti-interference and stability problem

[0015] EMI sensitivity: the motor is prone to mutual interference with high-frequency devices such as antennas during operation, and needs to rely on external filter circuits, but the low integration degree leads to limited shielding effect.

[0016] Vibration deflection and noise: the cuboid structure or asymmetric magnetic circuit design is prone to cause the deflection of the mover, excite the vibration mode in the non-target direction, produce collision noise, and reduce the user experience.

[0017] Insufficient durability: under high-frequency vibration, the magnetic steel is prone to demagnetization (service life <100,000 times), the elastic member is prone to fatigue fracture, and the traditional damping design (such as foam) is prone to aging failure.

[0018] 4. Manufacturing cost and process limitations

[0019] High cost of linear motor: the cost of a transverse linear motor (such as Apple Taptic Engine) is about $10, which is much higher than that of a rotor motor (about $1), hindering popularization.

[0020] Difficulty in manufacturing ultra-thin magnetic conductive members: for example, a 0.15mm thick Yoke needs to be precisely stamped, with high process tolerance requirements (±0.1°), and low yield (<80%).

[0021] Poor adaptability of automated production: traditional designs rely on manual assembly (such as foam insertion), which is difficult to adapt to SMT processes and has low production efficiency.

[0022] 5. Limitations of application scenarios

[0023] Single haptic feedback: existing technologies are difficult to simulate complex scenarios (such as game gun recoil, keyboard typing, etc.), rely on software tuning, and have a long adaptation cycle.

[0024] Difficulty in miniaturization and high-density compatibility: in compact devices (such as smart wearables), motor volume compression is prone to cause magnetic field attenuation, insufficient vibration, and increased heat dissipation problems, which increase the risk of magnetic steel demagnetization. SUMMARY

[0025] The application aims to provide an assembly process of a linear motor driving structure, which solves the problems of magnetic field attenuation and insufficient vibration feeling of a traditional vibration motor caused by size reduction through magnetic circuit optimization and structural innovation under an extremely compact size (16.2*5.1*2.4mm), and meets the demand for high-density tactile feedback in intelligent wearable devices, ultra-thin mobile phones and other scenarios. Through the collaborative design of M-shaped yoke iron and double-magnetic steel layout, the magnetic leakage is reduced and the magnetic induction strength is enhanced, thereby breaking through the problem of energy loss caused by high magnetic resistance of the traditional magnetic circuit (such as U-shaped yoke), and improving the driving efficiency. In view of the problems of magnetic steel demagnetization and structural fatigue of the micro-vibration motor in long-term high-frequency vibration, the layered magnetic circuit and integrated yoke design are adopted to improve the system stability and prolong the service life. Through the optimization of the precision stamping process of the ultra-thin yoke, the tolerance accumulation problem caused by the traditional multi-component assembly is solved, and high-precision and low-cost mass production is realized.

[0026] The object of the application can be achieved by the following technical solutions:

[0027] An assembly process of a linear motor driving structure, comprising the following steps:

[0028] M-shaped yoke iron process: high-precision progressive die stamping is adopted to form an M-shaped yoke iron;

[0029] A buckle or groove is designed at the edge of the M-shaped yoke iron, and cooperates with the inner wall of the through hole of the vibrator base body;

[0030] The magnetic steel is pre-fixed, and then is positioned by magnetic field adsorption;

[0031] The middle yoke iron and the coil skeleton are integrated by laser spot welding.

[0032] As a further technical solution of the application: the bending angle tolerance of the M-shaped yoke iron is ±0.1°.

[0033] As a further technical solution of the application: the surface roughness Ra of the M-shaped yoke iron is ≤0.8μm.

[0034] As a further technical solution of the application: the M-shaped yoke iron comprises a central connecting part and two side branches bent upward.

[0035] As a further technical solution of the application: the two side branches of the M-shaped yoke iron are bent at the same height and angle.

[0036] As a further technical solution of the application: the bending angle of the two side branches of the M-shaped yoke iron is 85°-90°.

[0037] As a further technical solution of the application: the two side magnetic steels are arranged alternately in up and down N / S directions, and cooperate with the M-shaped yoke iron to form vertical direction magnetic field superposition.

[0038] As a further technical solution of the present application: through the M-type yoke iron closed magnetic circuit, a three-dimensional closed loop is formed.

[0039] As a further technical solution of the present application: the specific path of the three-dimensional closed loop is as follows:

[0040] In turn through the left magnetic steel N-pole, M-type yoke iron left branch, central connecting part, M-type yoke iron right branch, magnetic steel S-pole, internal space, and return to the left magnetic steel N-pole, a three-dimensional closed loop is formed.

[0041] As a further technical solution of the present application: the M-type yoke iron is responsible for guiding the main magnetic circuit, and the middle Yoke forms a local high-density magnetic field in the coil working area.

[0042] The beneficial effects of the present application are:

[0043] The present application forms a closed loop through the three-dimensional magnetic circuit design of the M-type yoke iron, and the leakage magnetic rate is reduced to below 10%, so that the magnetic induction intensity is increased by more than 25% under the same volume, solving the problem that the flat plate or U-type Yoke of the traditional vibration motor has poor magnetic circuit closure, the leakage magnetic rate is as high as 30%-40%, the volume of the magnetic steel needs to be increased to compensate for the loss of the magnetic field, and the overall size is difficult to reduce;

[0044] The present application couples the double magnetic circuits of the embedded M-type yoke iron and the middle Yoke of the coil through the through hole, concentrates the magnetic field in the limited space, increases the driving force density by 40%, shortens the start-stop response time to within 10ms, and solves the problem that in the conventional design, the magnetic steel area and the coil space are compressed when the volume is reduced, resulting in insufficient driving force (weak vibration), delayed response (>20ms);

[0045] The present application balances the magnetic field distribution through the symmetrical M-type yoke iron branch, combines the layered arrangement of the upper and lower N / S pole magnetic steels, suppresses the vibration deflection, and has no performance attenuation after 500,000 endurance tests, solving the problem that the traditional motor is prone to deflection in vibration due to uneven magnetic pole distribution or assembly tolerance, resulting in noise, heating, and even structural damage;

[0046] The present application shortens the magnetic circuit length through the layered magnetic steel layout, cooperates with the magnetic conduction shunt of the M-type yoke iron, reduces the working point load of the magnetic steel, and theoretically increases the service life to more than 300,000 times, solving the problem that the traditional single magnetic circuit design is prone to local demagnetization under high temperature or high frequency working conditions due to the long magnetic circuit, and the service life is less than 100,000 times;

[0047] The present application optimizes the stamping compensation parameters (such as bending angle tolerance ±0.1°) of the M-type yoke iron, combines the self-positioning installation structure, and improves the good product rate to more than 95%, solving the problem that the good product rate is low (<80%) due to the stamping deformation of the ultra-thin magnetic conduction member (such as 0.15mm Yoke) and the high assembly precision requirement. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Fig. 1 This is a flow chart of a linear motor drive structure of the present invention;

[0050] Fig. 2 It is a structural schematic diagram of a linear motor drive structure of the present invention;

[0051] Fig. 3 It is a structural schematic diagram of a linear motor drive structure of the present invention;

[0052] In the figure, 1. housing; 2. M-shaped yoke; 3. magnet; 4. vibrator base; 5. spring; 6. middle yoke; 7. coil. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described 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 should fall within the scope of protection of the present invention.

[0054] Example 1

[0055] like Figs. 1-3 As shown, an embodiment of the present invention provides a linear motor drive structure, specifically comprising:

[0056] The housing 1 is used to install the M-shaped yoke 2, the vibrator base 4, the magnetic steel 3, the coil 7 and other structures;

[0057] The vibrator base 4 is made of a lightweight, non-magnetic material (such as aluminum alloy or engineering plastic), with dimensions of 16.2 mm in length, 5.1 mm in width, and 2.4 mm in thickness. A centrally located opening (6.1 x 3.5 mm) is provided for mounting the M-shaped yoke 2 and magnet 3 assembly. The vibrator base 4 is mounted to the inner wall of the housing 1 via a spring 5.

[0058] The M-shaped yoke 2 is stamped from 0.15mm thick high magnetic permeability alloy (silicon steel) and is symmetrically M-shaped, including a central connecting part and upwardly bent branches on both sides (branch height 1.2-1.5mm), and the total coverage area matches the through-opening.

[0059] M type yoke iron 2 is embedded in the through hole and fixed by laser welding or adhesion to form a closed magnetic circuit framework during installation.

[0060] The magnetic steel 3 is provided with two groups and is symmetrically installed in the groove body of the M type yoke iron 2. Each group of the magnetic steel 3 is arranged in layers from top to bottom. One group of the magnetic steel 3 has N-pole in the upper layer and S-pole in the lower layer, and the other group of the magnetic steel 3 has S-pole in the upper layer and N-pole in the lower layer, thereby forming an alternating magnetic field in the vertical direction.

[0061] The magnetic steel 3 is made of neodymium iron boron magnetic steel 3. The thickness of the single magnetic steel 3 is 1.5 mm. The width of the single magnetic steel 3 matches the groove body of the M type yoke iron 2. The length of the single magnetic steel 3 covers 90-95% of the width of the vibrator base body 4.

[0062] The coil 7 is provided with two groups and is installed at the bottom of the shell 1. The coil 7 is wound on the non-magnetic skeleton and is located at the bottom of the vibrator base body 4. After being electrified, the coil 7 generates an alternating magnetic field, which interacts with the magnetic field of the permanent magnet to drive vibration.

[0063] The middle yoke iron 6 is located between the two groups of the coil 7 and is also installed at the bottom of the shell 1. A strip-shaped magnetic conductor (thickness 0.8 mm, width 1.0-1.2 mm) is additionally arranged at the center position of the coil 7. The strip-shaped magnetic conductor is coupled with the M type yoke iron to form a magnetic circuit and further concentrate the magnetic field.

[0064] Example two

[0065] The linear motor driving structure provided by the embodiment of the application closes the magnetic circuit through the M type yoke iron 2 to form a three-dimensional closed loop. The specific path of the three-dimensional closed loop is as follows:

[0066] Taking the N-pole magnetic steel 3 located on the left side as an example:

[0067] The three-dimensional closed loop is formed by sequentially passing through the N-pole magnetic steel 3 on the left side, the left branch of the M type yoke iron 2, the central connecting part, the right branch of the M type yoke iron 2, the S-pole magnetic steel 3, the internal space and the N-pole magnetic steel 3 on the left side.

[0068] Taking the N-pole magnetic steel 3 located on the right side as an example:

[0069] The three-dimensional closed loop is formed by sequentially passing through the N-pole magnetic steel 3 on the right side, the right branch of the M type yoke iron 2, the central connecting part, the left branch of the M type yoke iron 2, the S-pole magnetic steel 3, the internal space and the N-pole magnetic steel 3 on the right side.

[0070] The three-dimensional closed loops of the N-pole magnetic steel 3 on the left side and the N-pole magnetic steel 3 on the right side are formed at the same time.

[0071] Further, the magnetic field of the double magnetic steel 3 is superposed

[0072] Vertical magnetic field enhancement: N / S poles of upper and lower layered magnetic steel 3 are arranged alternately, so that magnetic fields of adjacent poles are superimposed in the vertical direction, and the magnetic induction intensity is increased to 0.8-1.2T (about 0.5-0.7T in traditional design).

[0073] Further, the double-yoke iron coupling effect

[0074] Magnetic field concentration:

[0075] M-type yoke iron 2 is responsible for guiding the main magnetic circuit, and the middle yoke forms a local high-density magnetic field in the working area of the coil 7.

[0076] The magnetic field coupling of the double-yoke iron increases the magnetic flux density of the effective action area of the coil 7 by 40%, and the driving efficiency is significantly improved.

[0077] Example three

[0078] The linear motor driving structure provided by the embodiment of the application has the following functions of the M-type yoke iron 2:

[0079] Symmetrical vibration suppression;

[0080] M-type branch symmetry design: equal height and equal angle bending (bending angle 85°-90°) of the two branches, balanced magnetic field distribution, and suppressed vibration deflection (deflection angle <0.5°).

[0081] Pole symmetry arrangement: the polarity of the upper and lower layered magnetic steel 3 is symmetrically arranged, so as to eliminate the axial vibration interference caused by the imbalance of the single-sided magnetic field.

[0082] Ultra-thin yoke high-frequency response

[0083] Thin-wall magnetic conduction accelerates magnetic flux change: the 0.15mm ultra-thin yoke reduces hysteresis loss, cooperates with the alternating magnetic field of the coil 7, and shortens the start-stop response time to less than 10ms (about 15-20ms in traditional design).

[0084] Layered magnetic steel 3 anti-demagnetization design

[0085] Short magnetic circuit layout: the layered arrangement of the magnetic steel 3 shortens the magnetic circuit length by 30%, reduces the demagnetization risk, and increases the theoretical service life to more than 300,000 times.

[0086] Example three

[0087] The manufacturing and assembly process of the linear motor driving structure provided by the embodiment of the application comprises the following steps:

[0088] Step 1: precision stamping

[0089] M-type yoke iron process: high-precision progressive die stamping is adopted, the bending angle tolerance is controlled to be ±0.1°, the surface roughness Ra is less than or equal to 0.8μm, and the consistency of the magnetic conduction performance is ensured.

[0090] Self-positioning structure: A buckle or groove is designed on the edge of the Yoke to cooperate with the inner wall of the through-hole 4 of the vibrator base to achieve fast and accurate assembly (positioning accuracy ±0.05mm).

[0091] Step 2: Magnetic Steel 3 Fixing Process

[0092] Adhesive and magnetic composite fixation: Use high-temperature resistant epoxy adhesive to pre-fix the magnet 3, and then use magnetic field adsorption to assist positioning to avoid displacement under high-frequency vibration.

[0093] Step 3: Coil 7-Yoke Integration

[0094] Laser welding package: The middle yoke and coil 7 frame are integrated by laser spot welding to ensure magnetic circuit stability and isolate vibration transmission.

[0095] Working Principle of the Invention: This invention utilizes an M-shaped yoke closed magnetic circuit design, a three-layered vertical arrangement of dual magnetic steel, dual yoke magnetic field coupling, and an ultra-thin precision manufacturing process to construct a micro linear vibration motor vibrator structure with high magnetic efficiency, low loss, and fast response. Specific features include:

[0096] The spatial adaptation of the M-shaped yoke and the through-port achieves the unity of magnetic field efficiency and miniaturization.

[0097] The layered magnet 3 and double Yoke work together to break through the driving force density limitations of traditional single magnetic circuit.

[0098] Ultra-thin magnetic conductive parts are stamped and self-positioned to assemble, balancing low cost and high precision.

[0099] This technical solution can be widely used in fields with stringent requirements on space and performance, such as smart wearable devices and micro medical devices, and has significant market competitive advantages;

[0100] The present invention adopts the M-shaped high magnetic permeability thin-wall Yoke design, which has the following advantages:

[0101] Magnetic circuit optimization: The M-shaped structure forms a closed magnetic circuit through a three-dimensional magnetic path, reducing magnetic leakage (reduced by more than 30% compared to traditional U-shaped or flat Yoke) and significantly improving magnetic field utilization.

[0102] Lightweight and space-adaptable: The ultra-thin thickness of 0.15mm ensures magnetic conductivity while adapting to the miniaturized cavity (through-port size 6.1×3.5mm), making the overall volume of the vibrator 15%-20% smaller than similar products, making it suitable for compact scenarios such as smart wearable devices.

[0103] Enhanced high-frequency response: The symmetrical M-shaped branch design balances the magnetic field distribution, reduces vibration deflection, and improves high-frequency vibration stability.

[0104] Double magnetic steel 3 symmetrical N / S pole distribution and layered magnetic circuit

[0105] Magnetic field superposition effect: The upper and lower N / S poles of the two magnetic steels 3 are alternately arranged, and the vertical direction magnetic field superposition is formed by cooperating with the M-shaped yoke, so that the magnetic induction intensity is increased by about 25% (the actual measurement reaches 0.8-1.2T).

[0106] Anti-demagnetization design: The layered magnetic pole layout shortens the magnetic circuit length, reduces the risk of demagnetization, and prolongs the service life of the magnetic steel 3 (the theoretical service life is increased by 30%).

[0107] The application also has the following advantages through the coil 7-Yoke composite magnetic circuit architecture:

[0108] Performance improvement: Through the M-shaped yoke and the layout of the double magnetic steel 3, the magnetic field utilization rate is increased to more than 85%, which is significantly optimized compared with the traditional design (about 60%-70%), the driving efficiency is increased by 30%, and the energy consumption is reduced by 20%.

[0109] Miniaturization breakthrough

[0110] Compact size of 16.2x5.1x2.4mm, breaking the volume limit of micro vibration motors, providing high-density haptic solutions for ultra-thin mobile phones, AR / VR devices.

[0111] Reliability enhancement

[0112] The integrated structure of the M-shaped yoke reduces the assembly tolerance sensitivity, and the layered magnetic steel 3 fixed design passes the vibration durability test of 500,000 times without performance attenuation.

[0113] Cost efficiency

[0114] The ultra-thin yoke adopts a precision stamping process, the material utilization rate is increased by 40%, the production cost is reduced by 15%, and it is also compatible with automatic assembly.

[0115] Double Yoke synergistic effect: The Yoke through the vibrator and the middle Yoke of the coil 7 form a double magnetic circuit coupling, the driving magnetic field density is increased by 40%, and higher vibration intensity (up to 1.5G@200Hz) is realized.

[0116] Dynamic response optimization: The magnetic field concentration is increased, the force on the coil 7 is more linear, the start-stop time is shortened to less than 10ms, and it is suitable for high-precision haptic feedback requirements.

[0117] The above describes one embodiment of the application in detail, but the content described is only a preferred embodiment of the application, and cannot be considered as limiting the scope of the application. Any equivalent changes and improvements made within the scope of the application should still belong to the patent coverage of the application.

Claims

1. An assembly process for a linear motor drive structure, characterized in that: The following steps are involved: M-type yoke process: high-precision progressive die stamping is used to form the M-type yoke; Design a buckle or groove on the edge of the M-shaped yoke to match the inner wall of the through-hole of the vibrator base; Pre-fix the magnetic steel and then assist in positioning through magnetic field adsorption; The middle yoke and the coil frame are integrated by laser spot welding.

2. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The bending angle tolerance of the M-type yoke is controlled to ±0.1°.

3. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The surface roughness of the M-type yoke is Ra≤0.8μm.

4. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The M-shaped yoke includes a central connecting portion and two upwardly bent branches.

5. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The branches on both sides of the M-shaped yoke are bent at equal heights and angles.

6. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The bending angles of the branches on both sides of the M-shaped yoke are 85°-90°.

7. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The magnets on both sides are arranged alternately in N / S, and cooperate with the M-shaped yoke to form a vertical magnetic field superposition.

8. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The magnetic circuit is closed by the M-shaped yoke, forming a three-dimensional closed loop.

9. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The specific path of the three-dimensional closed loop is as follows: It passes through the left magnetic steel N pole, the left branch of the M-shaped yoke, the central connecting part, the right branch of the M-shaped yoke, the magnetic steel S pole, the internal space, and returns to the left magnetic steel N pole to form a three-dimensional closed loop.

10. The assembly process of a linear motor drive structure according to claim 1, characterized in that: The M-shaped yoke is responsible for guiding the main magnetic circuit, and the middle yoke forms a local high-density magnetic field in the working area of ​​the coil.

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