Linear motor structure

Abstract

The invention relates to the technical field of linear motors, and discloses a linear motor structure which comprises a lower shell and an upper shell, an oscillator is arranged in the upper shell, and magnetic steel is symmetrically arranged below the oscillator; a coil is arranged above the lower machine shell and located below the vibrator, a magnet yoke is arranged above the lower machine shell and located in the middle of the coil, and through the compact vibrator structure, the magnetic circuit design and the precision manufacturing process are optimized. The core problems that a traditional linear vibration motor is insufficient in driving force, too large in size, unstable in vibration, low in assembly precision and the like are solved, and the linear vibration motor is particularly suitable for application scenes such as intelligent wearing and ultra-thin mobile phones which have strict requirements for space and performance.

Description

Technical Field

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

[0002] Micro vibration motors are essential components in industries such as electronics, automotive, and home appliances, providing users with tactile feedback and vibration reminders. Linear motors have attracted significant attention due to their simple structure, suitability for high-speed linear motion, high primary winding utilization, lack of lateral edge effects, short response time, and long service life. They also offer a variety of vibration modes, providing users with rich, diverse, and realistic tactile feedback.

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

[0004] 1. Structural complexity and space occupancy: The large number of components makes assembly difficult: Traditional linear motors use a rectangular structure with numerous internal actuator components (such as elastic parts, magnets, and vibrators). The assembly steps are cumbersome, and tolerance accumulation can easily lead to performance deviations, resulting in high production costs.

[0005] 2. Low volume and space utilization: For example, the transverse linear motor (X-axis) requires a large horizontal space, affecting the layout of the phone's battery or other components. While the cylindrical vibrator design can optimize the center of gravity, it still requires complex assembly processes.

[0006] 3. Insufficient vibration performance and response speed: Insufficient driving force: Traditional electromagnetic drive relies on Ampere force, which has a small driving force and cannot meet the demand for high vibration sensation; some designs use foam damping parts to further weaken the driving force;

[0007] 4. Vibration, yaw, and noise: A rectangular structure or asymmetric magnetic circuit design can easily cause the mover to deflect, stimulating vibration modes in non-target directions, generating collision noise and reducing user experience.

[0008] 5. Insufficient durability: Under high-frequency vibration, the magnet is prone to demagnetization (lifespan < 100,000 times), the elastic parts are prone to fatigue fracture, and the traditional damping design (such as foam) is prone to aging and failure. Summary of the Invention

[0009] An object of the present invention is to provide a linear motor structure to solve the above-mentioned problems.

[0010] The purpose of the present invention can be achieved through the following technical solutions:

[0011] A linear motor structure includes a lower housing and an upper housing, wherein a vibrator is disposed inside the upper housing and magnets are symmetrically disposed below the vibrator;

[0012] A coil is arranged above the lower housing and below the vibrator, and a magnetic yoke is arranged above the lower housing and in the middle of the coil.

[0013] As a further solution of the present invention: a coil position is opened below the vibrator, and the coil above the lower housing is arranged in the coil position below the vibrator.

[0014] As a further solution of the present invention: a magnetic steel position is symmetrically provided below the vibrator and within the coil position, and the two magnetic steels are respectively arranged in the magnetic steel position.

[0015] As a further solution of the present invention: the magnetic poles of the two magnets are in opposite directions.

[0016] As a further solution of the present invention: a flexible circuit board is provided on the lower housing, and the flexible circuit board is electrically connected to the coil.

[0017] As a further solution of the present invention: the vibrator is connected to the upper housing via spring sheets symmetrically arranged on both sides.

[0018] As a further solution of the present invention: the material of the magnetic yoke is a high-permeability magnetic alloy

[0019] As a further solution of the present invention: the vibrator is made of non-magnetic lightweight material.

[0020] As a further solution of the present invention, the magnetic poles of the two magnets are in opposite directions, and are arranged in an upper and lower layered N / S pole alternating arrangement.

[0021] As a further solution of the present invention: the coil is wound with multiple turns of flat copper wire.

[0022] Beneficial effects of the present invention:

[0023] By optimizing the magnetic steel layout (upper and lower N / S distribution) and adding a bottom Yoke structure, magnetic leakage is reduced and the magnetic field concentration is enhanced, thereby improving the driving force and response speed of the vibration motor, and solving the problems of low magnetic field utilization and weak vibration sensation caused by unreasonable magnetic circuit design in traditional linear motors.

[0024] The vibrator size (11×5.1×1.6mm) and the overall motor size (6×15×2.5mm) are highly compact, achieving an ultra-thin and compact design, suitable for miniaturized devices. It is suitable for scenarios with strict space requirements such as smart wearable devices (such as TWS headphones, smart watches) and ultra-thin mobile phones, solving the problem that traditional motors cannot adapt to miniaturized devices due to their large size.

[0025] A symmetrical magnetic steel layout (gaps on both sides + middle spacer) and a bottom yoke magnetic conductive structure are used to reduce vibration deflection, improve the accuracy of vibration direction, optimize vibration stability and anti-interference ability, and solve the problems of unstable vibration and high noise caused by asymmetric magnetic circuit in traditional motors.

[0026] The gaps on both sides of the vibrator (1.55×3.1mm, 0.8mm interval) are used to precisely position the magnetic steel, avoiding the tolerance accumulation problem caused by traditional assembly methods, improving assembly accuracy and manufacturing yield. The bottom coil and Yoke adopt a precision stamping process to ensure the consistency of the magnetic circuit, improve the mass production yield, and solve the performance fluctuation problem of traditional motors caused by manual assembly or poor tolerance control.

[0027] In summary, through a compact vibrator structure, optimized magnetic circuit design (N / S magnets and yokes) and precision manufacturing process, the core problems of traditional linear vibration motors such as insufficient driving force, excessive size, unstable vibration, and low assembly precision have been solved. It is particularly suitable for application scenarios such as smart wearables and ultra-thin mobile phones that have strict requirements on space and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] Figure 1 It is a schematic cross-sectional view of the overall structure of the present invention;

[0030] Figure 2 It is a schematic diagram of the vibrator structure in the present invention;

[0031] Figure 3 It is a schematic diagram of the coil structure of the present invention.

[0032] In the figure: 1. Upper housing; 2. Lower housing; 3. Vibrator; 30. Coil position; 31. Magnet position; 4. Magnet; 5. Yoke; 6. Coil; 7. Flexible circuit board; 8. Spring sheet. DETAILED DESCRIPTION

[0033] 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 any creative efforts shall fall within the scope of protection of the present invention.

[0034] See also Figure 1-Figure 3As shown, the present invention is a linear motor structure, comprising a lower housing 2 and an upper housing 1. A vibrator 3 is disposed within the upper housing 1 and connected to the upper housing 1 via spring sheets 8 symmetrically disposed on both sides. The vibrator 3 is made of a non-magnetic lightweight material, such as an aluminum alloy or a titanium alloy, and has dimensions of 11 mm in length, 5.1 mm in width, and 1.6 mm in thickness. The overall volume is compressed to fit within the adaptation range of micro-devices, which can be smart wearable watches, headphones, ultra-thin mobile phones, etc.

[0035] Below the vibrator 3 and within the coil position 30, symmetrically positioned magnetic steel positions 31 are provided. The magnetic poles of the two magnets 4 are oriented in opposite directions. The magnet positions 31 measure 1.55 × 3.1 mm, are 0.6 mm deep, and are spaced 0.8 mm apart. These positions are used to precisely secure the magnets and prevent vibration displacement. Each magnet position 31 contains a magnet 4 measuring 3 × 1.5 × 0.6 mm. The magnets are arranged in an alternating upper and lower layered arrangement with N / S poles. Adjacent magnets 4 are spaced 0.8 mm apart, forming a vertically closed magnetic circuit.

[0036] The gaps (1.55×3.1mm, 0.8mm apart) on both sides of the vibrator 3 are used to precisely position the magnetic steel 4, avoiding the tolerance accumulation problems caused by traditional assembly methods. The bottom coil 6 and yoke 5 are precision stamped to ensure magnetic circuit consistency and improve mass production yield.

[0037] Solve the performance fluctuation problem of traditional motors caused by manual assembly or poor tolerance control

[0038] Through the symmetrical N / S pole layout, the magnetic flux lines are superimposed in the vertical direction, and the magnetic induction intensity is increased to 0.9-1.3T, while the traditional design is about 0.6-0.8T; by optimizing the layout of the magnet 4 and adding a bottom magnetic yoke 5 structure, the leakage flux is reduced and the magnetic field concentration is enhanced, thereby improving the driving force and response speed of the vibration motor, and solving the problems of low magnetic field utilization and weak vibration induction caused by unreasonable magnetic circuit design in traditional linear motors.

[0039] During the production process of the vibrator 3, the coil position 30 is laser cut to ensure dimensional accuracy (±0.02mm) and surface flatness (Ra≤0.4μm). The magnet position 31 is pre-set within the coil position 30 (with a tolerance of ±0.03mm) and magnetically assisted assembly is used to achieve quick and accurate installation of the magnet 4.

[0040] A coil 6 is disposed above the lower housing 2 and below the vibrator 3. The bottom rectangular coil has outer dimensions of 3.4 × 5.1 mm, inner dimensions of 1.0 × 2.7 mm, and a thickness of 0.45 mm. It is wound with multiple turns of flat copper wire to reduce eddy current losses. A coil position 30 is provided below the vibrator 3. The coil 6 above the lower housing 2 is disposed within the coil position 30 below the vibrator 3. A magnetic yoke 5 is disposed above the lower housing 2 and in the middle of the coil 6.

[0041] The coil 6 skeleton and the yoke 5 are integrally formed by precision stamping, eliminating the magnetic circuit gap caused by traditional gluing (gap <0.01mm). The coil 6 and yoke 5 components are encapsulated by vacuum coating to isolate moisture and mechanical wear, improving durability (lifespan ≥ 500,000 times);

[0042] When energized, coil 6 interacts with the magnetic field of magnet 4, generating a driving force perpendicular to the direction of motion of vibrator 3, driving vibrator 3 to linear reciprocating vibration. A strip-shaped magnetic yoke 5, measuring 0.8×2.4×0.45mm and made of a high-permeability superalloy (SPCC), is positioned at the center of coil 6. This structure enhances the magnetic conductivity of yoke 5. Furthermore, yoke 5 acts as a magnetic core, concentrating magnetic flux lines within the effective working area of ​​coil 6 and reducing magnetic leakage, resulting in a magnetic leakage rate of less than 10%. This increases the magnetic flux density in the active area of ​​coil 6 by 40%.

[0043] In this solution, the magnetic circuit is a three-dimensional closed circuit. The path is designed as follows: the north pole of magnet 4 → the side wall of magnet position 31 → the bottom yoke 5 → the coil 6 area → the south pole of magnet 4 → the north pole of return magnet 4, forming a vertical closed loop. The spacing between the yoke 5 and the magnet 4 is coordinated to shorten the magnetic circuit length by 30% compared to traditional designs, reducing magnetic resistance and increasing the driving force density to 1.2G / Hz@200Hz, making the magnetic field more concentrated.

[0044] The symmetrical distribution of magnets 31 on both sides (with a tolerance of ±0.05mm) balances the magnetic field force, suppresses vibration deflection (deflection angle <0.3°), and ensures vibration stability. The vibrator 3 is only 1.6mm thick, reducing motion inertia and shortening the start-stop response time to 8ms (compared to approximately 15ms in traditional designs), achieving a lightweight design.

[0045] A flexible circuit board 7 is provided on the lower housing 2 and is electrically connected to the coil 6;

[0046] In the scheme, a symmetrical gap magnet 4 layout plus a bottom magnetic yoke 5 is used to conduct magnetism, which reduces vibration deflection, improves the accuracy of vibration direction, realizes efficient use of magnetic field and compatibility with miniaturization, and solves the problems of unstable vibration and loud noise caused by asymmetric magnetic circuit of traditional motors. The vertical closed magnetic circuit design increases the magnetic induction intensity to 1.3T and the driving force density to 1.5G / Hz. The laser cutting and magnetic positioning process improves the assembly accuracy to ±0.03mm and the mass production yield is ≥98%. The technical effect is that the driving force is increased by 50% compared with similar micro motors, and the response time is shortened to 8ms, suitable for high-precision tactile feedback scenarios (such as VR controllers and smart rings). With an overall size of 6×15×2.5mm, it is one of the thinnest linear motors and can be embedded in the handle of TWS headphones or the middle frame of ultra-thin mobile phones. This solves the problem that traditional motors are too large to adapt to miniaturized devices. It has passed 500,000 vibration tests without magnetic steel demagnetization or structural fatigue. The operating temperature range is -40°C to 85°C. Through systematic optimization of structure, magnetic circuit and process, it has solved the technical bottlenecks of micro vibration motors in driving force, size and stability, and has significant market competitiveness.

[0047] Through a compact vibrator 3 structure, optimized magnetic circuit design (N / S magnets and yokes) and precision manufacturing processes, the core problems of traditional linear vibration motors such as insufficient driving force, excessive size, unstable vibration and low assembly accuracy are solved. It is particularly suitable for application scenarios such as smart wearables and ultra-thin mobile phones that have strict requirements on space and performance.

[0048] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A linear motor structure, characterized in that: It comprises a lower housing (2) and an upper housing (1), wherein a vibrator (3) is arranged inside the upper housing (1), and magnetic steel (4) is symmetrically arranged below the vibrator (3); A coil (6) is provided above the lower housing (2) and below the vibrator (3), and a magnetic yoke (5) is provided above the lower housing (2) and in the middle of the coil (6).

2. A linear motor structure according to claim 1, characterized in that: A coil position (30) is provided below the vibrator (3), and the coil (6) above the lower housing (2) is arranged in the coil position (30) below the vibrator (3).

3. The linear motor structure according to claim 1, characterized in that: A magnetic steel position (31) is symmetrically provided below the vibrator (3) and within the coil position (30), and the two magnetic steels (4) are respectively arranged within the magnetic steel position (31).

4. The linear motor structure according to claim 3, characterized in that: The magnetic poles of the two magnetic steels (4) are in opposite directions.

5. The linear motor structure according to claim 1, characterized in that: A flexible circuit board (7) is provided on the lower housing (2), and the flexible circuit board (7) is electrically connected to the coil (6).

6. The linear motor structure according to claim 1, characterized in that: The vibrator (3) is connected to the upper housing (1) via spring sheets (8) symmetrically arranged on both sides.

7. The linear motor structure according to claim 1, characterized in that: The material of the magnetic yoke (5) is a high-permeability magnetic alloy.

8. The linear motor structure according to claim 1, characterized in that: The vibrator (3) is made of non-magnetic light material.

9. The linear motor structure according to claim 1, characterized in that: The magnetic poles of the two magnets (4) are in opposite directions, and are arranged in an upper and lower layered N / S pole alternating arrangement.

10. The linear motor structure according to claim 1, characterized in that: The coil (6) is wound with multiple turns of flat copper wire.

Images