A micro electromagnet guided by double sliding bearings

Abstract

The utility model discloses a kind of double sliding bearing guiding's micro electromagnet, belong to electromagnet technical field, including shell, the one end of the shell is provided with circuit board end cover;Coil assembly and armature assembly are provided in shell, and the armature of armature assembly driven by coil assembly is axially slid in and out in the other end of shell away from circuit board end cover;Coil assembly is composed of framework, wire body, and framework is magnetically permeable core, wire body is wound on framework.This double sliding bearing guiding's micro electromagnet is optimized product structure, utilize magnetically permeable core as the framework of coil assembly, improve the magnetic field generated by coil, to improve magnetic field utilization, and then improve driving force, so that product performance is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of electromagnet technology and provides a miniature electromagnet guided by double sliding bearings. Background Technology

[0002] The conventional electromagnet structure in existing technology is relatively simple. On one hand, the coil part consists of a hollow coil or a coil wound on a plastic support. Under the premise of the same volume, the electromagnetic force generated by the coil is small, resulting in low space utilization. On the other hand, the armature part is guided by a bushing, and the bearing is made of plastic or machined metal. The materials themselves have poor self-lubricating properties and high friction, which negates the attraction force generated by the electromagnet. In addition, the guide bushing is only set at one end of the armature. When the electromagnet is energized and generates attraction force, the armature will be attracted radially, which will greatly increase the friction between the armature and the bushing, causing the armature to get stuck or rub against the iron core, resulting in noise or malfunction. Therefore, the conventional electromagnet structure used in small spaces has the following problems:

[0003] 1) Electromagnets are inefficient and cannot maximize their electromagnetic force in small spaces;

[0004] 2) Friction is a crucial indicator for miniature electromagnets; the greater the friction, the smaller the electromagnet's thrust.

[0005] 3) Noise: Due to insufficient radial positioning and the lack of a buffer and noise reduction device in the axial direction, noise is easily generated.

[0006] Therefore, it is necessary to improve the design of the existing electromagnet structure to meet the key performance requirements of the demand side, and thus redesign a miniature electromagnet structure with double sliding bearing support and guidance. Utility Model Content

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a miniature electromagnet guided by double sliding bearings. By optimizing the product structure, it not only improves the magnetic field generated by the coil to enhance the magnetic field utilization rate and thus the driving force, but also optimizes and solves various problems related to friction through the positioning structure of the double sliding bearings and the armature.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] This utility model discloses a miniature electromagnet guided by double sliding bearings, including a housing, which provides protection for the internal structure and maintains the stability of the components. One end of the housing has a circuit board end cap for connecting and protecting the circuit board, ensuring the normal operation of the electromagnet's electronic control components. Inside the housing are a coil assembly and an armature assembly that cooperates with the coil assembly. The armature of the armature assembly is driven by the coil assembly to slide axially in and out at the end of the housing away from the circuit board end cap. The armature, as the core part of the armature assembly, is attracted and driven by the magnetic field generated by the coil assembly, completing the functions of adsorption and release. The coil assembly consists of a frame and a wire. The frame is a magnetically conductive iron core, providing a good magnetic flux path and improving the electromagnet's magnetic field generation capability. The wire is wound on the frame and generates a magnetic field through electromagnetic induction when energized, thereby driving the armature assembly to move. Thus, when current passes through the coil assembly, a strong magnetic field is generated, and the armature is attracted by the magnetic force and slides towards the circuit board end cap of the housing.

[0010] Optionally, the housing also includes a sliding bearing fitted onto the armature and slidingly engaging it axially, providing guidance for the armature and ensuring smooth sliding. Two sliding bearings are spaced apart to effectively distribute the load generated by the armature during sliding, maintaining its stability. A bushing is placed between the two sliding bearings to provide additional support. The bushing design enhances structural stability, effectively preventing the armature from shifting during sliding and ensuring the required precise operation. Thus, by employing double sliding bearings, friction is reduced, the armature's response speed and thrust are improved, ensuring no jamming during movement and reducing noise. The application of double sliding bearings ensures smooth and friction-free movement of the armature, while allowing it to quickly return to its original position when needed, forming an efficient working cycle.

[0011] Optionally, an oil-lubricated bearing is used, where the sliding bearing is lubricated under vacuum. This type of sliding bearing ensures that the lubricating oil is evenly wetted on the bearing surface through vacuum immersion, thus forming a good lubricating film. This significantly reduces the coefficient of friction, decreases the resistance of the armature during movement, and further enhances the thrust output and response speed of the electromagnet. Good lubrication also reduces machine wear, extends the service life of the bearing and armature, and lowers maintenance costs. Simultaneously, it reduces noise; the protective layer formed by the lubricating oil reduces the noise generated by metal-to-metal friction, keeping the electromagnet quieter during operation.

[0012] Optionally, the bushing can be made of non-magnetic metal or plastic, such as aluminum alloy or stainless steel. These materials offer the advantage of being lightweight while maintaining strength and wear resistance. Using a bushing made of non-magnetic metal avoids magnetic field interference, ensuring the electromagnet's performance, and the better thermal conductivity of the metal bushing aids in heat dissipation and improves the electromagnet's operational stability. Alternatively, commonly used plastic materials such as polyoxymethylene (POM) and polyethylene (PE) possess good wear resistance and self-lubricating properties. Plastic bushings have a lower coefficient of friction and are generally non-conductive, better preventing short circuits or electromagnetic interference. Furthermore, plastic materials have strong corrosion resistance and chemical stability, making them suitable for use in various environments.

[0013] Optionally, the armature assembly also includes a retaining ring snapped onto the armature body and located between two sliding bearings. This retaining ring is designed to be securely mounted on the armature body through elastic deformation, providing support for a telescopic spring and thus enhancing the reciprocating motion performance of the electromagnet's armature. A telescopic spring is fitted onto the armature body and between the retaining ring and a sliding bearing near the coil assembly. This telescopic spring has a certain elasticity, providing a reaction force when the armature moves towards the coil assembly. Thus, the main function of the telescopic spring is to buffer and absorb the impact generated during the sliding of the armature, preventing noise and wear caused by excessively vigorous movement, and also helping to ensure that the coil assembly can quickly return the armature to its initial position when not energized.

[0014] Optionally, a buffer pad is provided on the side of the retaining ring facing away from the telescopic spring, i.e., the side of the retaining ring that does not directly contact the telescopic spring. Another buffer pad is also provided on the corresponding side of the frame facing the armature; this means there is also cushioning material at the point of contact between the armature and the frame. This buffer pad is made of foam, such as polyurethane foam. It possesses excellent elasticity and compressibility, effectively absorbing shocks and vibrations, thereby mitigating noise and impact forces generated by the electromagnet during operation. In this way, the buffer pad design significantly reduces direct contact between the armature and the frame, and between the retaining ring and the sliding bearing, allowing for effective absorption of impact forces when the armature moves to its limits, reducing wear and noise caused by hard contact, and improving operational comfort.

[0015] Optionally, the circuit board end cap is provided with an FPC board electrically connected to the lead-out terminals of the wire. This FPC boasts excellent flexibility and lightweight characteristics, allowing it to adapt to the compact design of miniature electromagnets and facilitating installation and wiring in confined spaces. Furthermore, using an FPC board simplifies wiring, reducing installation time and complexity associated with traditional connection methods.

[0016] Compared with the prior art, the present invention has one or more of the following advantages:

[0017] 1. Double sliding bearing design: The design of double sliding bearings with bushings significantly reduces the friction of the armature during sliding, improves the smoothness and guidance of the motion, and ensures that the electromagnet has sufficient thrust to enhance the thrust output of the electromagnet.

[0018] 2. Optimize coil structure: Improve the design of the coil by using a magnetically conductive iron core as the coil frame, so that it can generate a stronger magnetic field under the same volume conditions, improve the utilization rate of electromagnetic force, and thus enhance the performance of the electromagnet.

[0019] 3. Improved noise control: The design has been optimized to address the axial buffering issue, with appropriate front and rear buffer pads installed to reduce noise, thereby effectively reducing the noise generated by the electromagnet during operation.

[0020] 4. Smoothness of movement: The combination of snap ring and telescopic spring can effectively reduce the swaying and impact of the armature during movement, improve the smoothness of movement of the entire miniature electromagnet, and has a simple structure, low cost and easy assembly.

[0021] In summary, the dual sliding bearing guided miniature electromagnet of this invention overcomes problems such as low efficiency, high friction, and severe noise by improving the structure of traditional electromagnets, and significantly improves the overall performance of miniature electromagnets.

[0022] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0024] Figure 1 This is a perspective view of the miniature electromagnet guided by double sliding bearings according to this utility model.

[0025] Figure 2 for Figure 1 Axial section view;

[0026] Figure 3 for Figure 1 Exploded view;

[0027] Figure 4 for Figure 1 A schematic diagram of the coil assembly in the diagram;

[0028] Figure 5 for Figure 1A schematic diagram of the armature assembly in the middle;

[0029] Reference numerals: 1. Circuit board end cap; 2. Housing; 3. Coil assembly; 4. Sliding bearing; 5. Bushing; 6. Telescopic spring; 7. Armature assembly; 8. Buffer pad; 31. Frame; 32. Wire body; 71. Armature; 72. Snap ring. Detailed Implementation

[0030] The technical features of this utility model will be further described in detail below with reference to the accompanying drawings so that those skilled in the art can understand them.

[0031] like Figure 1-5 As shown, this miniature electromagnet guided by double sliding bearings mainly consists of a circuit board end cover 1, a housing 2, a coil assembly 3, a sliding bearing 4, a bushing 5, a telescopic spring 6, an armature assembly 7, and a buffer pad 8. Among them, the housing 2 is the supporting carrier of the miniature electromagnet, and its internal space is used to accommodate the various parts of the electromagnet. At the same time, the housing 2 is made of magnetically conductive material and is part of the magnetic circuit. The selection of magnetically conductive material can effectively converge the magnetic lines of force generated by the coil assembly 3, thereby improving the efficiency of the electromagnet.

[0032] The sliding bearing 4 is a powder metallurgy product, and its shape is formed by mold pressing, which can well ensure the product size progress. The sliding bearing 4 itself has many tiny pores, and lubricating oil is impregnated into the bearing through vacuum impregnation. When the armature assembly 7 slides in contact with the sliding bearing 4, the lubricating oil in the sliding bearing 4 is released and forms an oil film between it and the armature body 71 of the armature assembly 7, thereby playing a role in lubrication and reducing friction. The two sliding bearings 4 are respectively set at both ends of the armature body 71. When the armature body 7 works back and forth, it can effectively ensure that the armature body 71 only moves axially, preventing noise and friction loss caused by friction between the armature body 71 and other components.

[0033] Bushing 5 is a support component that supports two sliding bearings 4 spaced apart according to design specifications. It can be a non-magnetic metal product or a plastic product.

[0034] The armature assembly 7 is the moving part of the electromagnet. When the coil assembly 3 is energized, it generates an electromagnetic force, which attracts the armature assembly 7 to move axially. The armature assembly 7 includes: armature body 71, retaining spring 72 and buffer pad 8. The armature body 71 is made of magnetic material. The electromagnetic force generated by the coil assembly 3 attracts the armature body, causing it to move. The retaining spring 72 is clamped to a designated position on the armature body 71 through an interference fit, thereby restricting the movement of the armature body 71 so that the armature body 71 can only reciprocate between the two sliding bearings 4. The buffer pad 8 has an adhesive backing, which is used to stick to the retaining spring 72, so that when the armature body 71 moves outward, the retaining spring 72 will not rigidly collide with the sliding bearings 4, reducing the risk of noise and deformation.

[0035] The function of the telescopic spring 6 is as follows: when the electromagnet is not energized, the telescopic spring 6 pushes the armature 71 to be fixed in the initial position; when the coil assembly 3 is energized and the electromagnetic force generated is greater than the pushing force and friction of the telescopic spring 6, the armature 71 moves forward; when the coil assembly 3 is de-energized, the armature 71 returns to the initial position under the pushing force of the telescopic spring 6.

[0036] The coil assembly 3 serves as the excitation source for the miniature electromagnet. When energized, it generates an electromagnetic force that attracts the armature assembly 7 to move. The coil assembly 3 includes a frame 31 and a wire 32. The frame 31 is a core made of magnetically conductive material and is an important part of the magnetic circuit, effectively enhancing the electromagnetic force generated by the coil assembly 3. Simultaneously, the core-type frame 31 is a structural component on which the wire 32 is directly wound, significantly improving the strength and precision of the coil assembly 3. The wire 32 is made of polyurethane enameled wire with an insulating layer and a self-adhesive layer on its surface. It is automatically wound onto the frame 31, and the frame 31 has two notches at both ends for the wire. The wound wire 32 is led out from these notches and electrically connected to the circuit board end cap 1. Additionally, a buffer pad 8 is provided on the corresponding surface of the frame 31 facing the armature 71 to prevent rigid collisions and reduce noise and deformation risks. This buffer pad 8 can be made of foam material.

[0037] The circuit board end cover 1 serves as the lead-out position and fixing component for the electromagnet's wires. It mainly involves the cover body and the FPC board. After the cover body is installed into the housing 2, the internal materials of the electromagnet are fixed by riveting the housing. An FPC board is provided at the rear of the cover body, and the FPC board has adhesive backing. It is attached to the cover body by the adhesive backing to form the circuit board end cover 1. The FPC board has two solder pads and two PAD positions. The solder pads are used to solder the two wire ends of the coil assembly 3 leading out from the notch of the frame 31. The PADs are used for the user end to conduct power to the coil assembly 3.

[0038] The working principle of this miniature electromagnet is explained below: This product is a functional device that provides reciprocating motion, which can drive the load to perform switching or latching actions, and can be applied to scenarios that require reciprocating motion. Specifically, when an external power source supplies power to the coil assembly 3 via the PAD position on the FPC board of the circuit board end cover 1, the skeleton 31 of the coil assembly 3 acts as a magnetic core, enhancing the strength of the magnetic field. The resulting electromagnetic force acts on the armature assembly 7, attracting its movement. This causes the armature to move towards the circuit board end cover 1 of the housing due to the magnetic field, allowing other components or loads to be attracted or pushed. When the coil assembly 3 is de-energized, the power supply stops, and the magnetic field disappears. At this time, the armature assembly 7 is no longer attracted by the electromagnetic force. To enable the armature 7 to quickly return to its initial position, a telescopic spring 6 is designed. This spring 6 provides a reverse thrust when the coil assembly 3 is not powered, pushing the armature 7 back to its original position. This reciprocating cycle, by repeating this power-on and power-off process, allows the armature assembly 7 to periodically reciprocate, realizing the opening and closing or pushing function of the electromagnet. This reciprocating motion enables the miniature electromagnet to have rapid response and efficient control capabilities in various applications.

[0039] This product is a driving component for electronic terminal products. The main requirements for this type of device in electronic terminal products are as follows: First, size: for electronic products, the smaller the size of the electronic component, the better, while still meeting functional requirements; second, thrust: thrust is a key indicator of this product, and the greater the thrust generated within a limited product volume, the better; third, noise: considering the characteristics of this product, axial collisions are inevitable during operation, and these collisions will produce sound. The lower the noise generated under rated operating conditions, the better. Therefore, this miniature electromagnet guided by double sliding bearings significantly enhances the electromagnetic field by incorporating a magnetic core within the coil assembly. Furthermore, by placing a sliding bearing at each end of the armature assembly, with the bearings themselves lubricated, friction is effectively reduced, fundamentally solving the lateral impact noise or jamming caused by radial attraction. Additionally, by placing a buffer pad at each end along the axial direction, the noise generated by impacts during operation is effectively reduced.

[0040] The main technical features of this miniature electromagnet guided by double sliding bearings are:

[0041] 1. Guiding structure with double sliding bearings and bushings. Two spaced sliding bearings with bushings in between provide bidirectional guidance and support for the armature assembly, significantly reducing friction and radial offset, and improving motion smoothness and thrust output.

[0042] 2. Magnetic core as coil frame. Replacing the traditional non-magnetic plastic frame with a magnetic core enhances magnetic field concentration, improves electromagnetic conversion efficiency, and generates greater electromagnetic force within the same volume.

[0043] 3. Lubrication of oil-impregnated sliding bearings. Sliding bearings achieve self-lubrication through a vacuum oil impregnation process, reducing the coefficient of friction, decreasing wear and noise, and extending service life.

[0044] 4. Buffer structure and spring return mechanism. A retaining ring, a telescopic spring, and a foam buffer pad are set in the armature assembly to achieve axial buffering and rapid return, reducing impact noise and mechanical damage.

[0045] 5. FPC board integration and connection. An FPC flexible circuit board is integrated onto the circuit board end cover, simplifying the wiring structure and adapting to miniaturization and high-density assembly requirements.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A miniature electromagnet guided by double sliding bearings, comprising a housing (2), characterized in that, One end of the housing (2) is provided with a circuit board end cap (1); a coil assembly (3) and an armature assembly (7) are provided inside the housing (2), and the armature (71) of the armature assembly (7) is driven by the coil assembly (3) to slide in and out axially at the other end of the housing (2) away from the circuit board end cap (1); the coil assembly (3) is composed of a skeleton (31) and a wire (32), and the skeleton (31) is a magnetic iron core, and the wire (32) is wound on the skeleton (31).

2. The miniature electromagnet guided by double sliding bearings according to claim 1, characterized in that, The housing (2) is also provided with a sliding bearing (4) that is fitted on the armature (71) and slides axially therewith. The sliding bearing (4) is provided as two that are arranged at intervals, and a bushing (5) is provided between the two sliding bearings (4) to provide support.

3. The miniature electromagnet guided by double sliding bearings according to claim 2, characterized in that, The sliding bearing (4) is an oil-bearing bearing infiltrated by lubricating oil under vacuum.

4. The miniature electromagnet guided by double sliding bearings according to claim 2, characterized in that, The bushing (5) is a non-magnetic metal or plastic product.

5. The miniature electromagnet guided by double sliding bearings according to any one of claims 2-4, characterized in that, The armature assembly (7) also includes a retaining ring (72) that snaps onto the armature (71) and is located between the two sliding bearings (4), and a telescopic spring (6) is fitted onto the armature (71) and the retaining ring (72) between it and one of the sliding bearings (4) near the coil assembly (3).

6. The miniature electromagnet guided by double sliding bearings according to claim 5, characterized in that, The retaining ring (72) has a cushioning pad (8) on the side facing away from the telescopic spring (6), and the frame (31) also has another cushioning pad (8) on the corresponding side facing the armature (71); the cushioning pad (8) is foam.

7. The miniature electromagnet guided by double sliding bearings according to claim 1, characterized in that, An FPC board electrically connected to the lead wire of the line body (32) is provided on the end cover (1) of the circuit board.

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