An interference shielded voice coil motor

Abstract

The utility model discloses a kind of anti-interference shield voice coil motor, including stator and mover, the stator includes base, magnet assembly and shell, the shell outside is equipped with first metal shielding net, the shell inside is embedded with tubular silicon steel column, the magnet assembly includes first magnet and second magnet, the first magnet outside is equipped with aluminium annular short circuit ring, the first magnet is fixedly connected with the tubular silicon steel column inside, the second magnet is fixedly connected with the base middle part, the shell is connected with the base and makes the second magnet be embedded in the first magnet, the mover includes conducting coil, the conducting coil is embedded in the gap between the first magnet and the second magnet.The technical scheme of the utility model can reduce magnetic flux leakage, and strengthen the effect of anti-electromagnetic interference.

Description

Technical Field

[0001] This utility model relates to the field of voice coil motor technology, and in particular to an anti-interference shielded voice coil motor. Background Technology

[0002] Photolithography machines used in integrated circuit manufacturing include a light source and a substrate for placing wafers. Light shines on designated areas of the wafer coated with a photosensitive material, completing the exposure and etching the desired circuit pattern onto the wafer. Furthermore, the wafer is placed on the substrate and fixed by a wafer lifting device, which uses electromagnetic force provided by a voice coil motor to move the wafer up and down. Therefore, the performance of the voice coil motor directly affects the performance of the photolithography machine. The voice coil motor consists of two parts: a magnet and a coil. The magnet is the moving part, and the coil is the stationary part. When the coil is energized, it controls the up and down movement of the magnet, thereby providing power to the wafer lifting device.

[0003] However, in the existing technology, voice coil motors have a lot of magnetic leakage, resulting in low motor output and greater mutual interference with surrounding components. Utility Model Content

[0004] The main purpose of this invention is to propose an anti-interference shielded voice coil motor, which aims to solve the existing technical problem of excessive magnetic leakage.

[0005] To achieve the above objectives, this utility model proposes an anti-interference shielded voice coil motor, comprising a stator and a mover. The stator includes a base, a magnet assembly, and a housing. A first metal shielding mesh is fitted on the outer side of the housing, and a tubular silicon steel column is embedded on the inner side of the housing. The magnet assembly includes a first magnet and a second magnet. An aluminum annular short-circuit ring is fitted on the outer side of the first magnet. A groove matching the aluminum annular short-circuit ring is provided on the inner side of the tubular silicon steel column. The first magnet is fixedly connected to the inner side of the tubular silicon steel column so that the aluminum annular short-circuit ring is embedded in the groove. The second magnet is fixedly connected to the middle of the base. The housing is snapped into the base so that the second magnet is embedded in the first magnet. The mover includes a conductive coil, which is embedded in the gap between the first magnet and the second magnet.

[0006] Preferably, the outer casing is made of conductive metal.

[0007] Preferably, a second metal shielding mesh is provided on the outside of the conductive coil, and the second metal shielding mesh is electrically connected to the outer shell.

[0008] Preferably, the first metal shielding mesh is a brass mesh tube.

[0009] Preferably, the surface of the brass mesh tube is provided with heat dissipation fins.

[0010] Preferably, the second metal shielding mesh is a copper-nickel alloy mesh.

[0011] The technical solution of this utility model has the following beneficial effects: The technical solution of this utility model absorbs the external low-frequency magnetic field by utilizing the high magnetic permeability of the tubular silicon steel column. When the motor is running, the leakage magnetic field passes through the aluminum ring and induces eddy currents. The reverse magnetic field generated by the eddy current cancels the leakage magnetic field (similar to the leakage magnetic field suppression principle of the transformer), thereby reducing the leakage magnetic field. Furthermore, the first metal shielding mesh and the outer shell form a double-layer shielding structure, which further improves the shielding effectiveness against low-frequency magnetic fields. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the overall structure of an anti-interference shielded voice coil motor according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of an anti-interference shielded voice coil motor according to an embodiment of the present invention.

[0014] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0015] Reference numerals: 1. Base; 2. Outer shell; 3. First metal shielding mesh; 4. Tubular silicon steel column; 5. Second magnet; 6. Conductive coil; 7. Second metal shielding mesh; 8. First magnet; 9. Aluminum annular short-circuit ring. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0018] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0019] This invention proposes an anti-interference shielded voice coil motor.

[0020] like Figures 1 to 2 As shown in one embodiment of this utility model, the anti-interference shielded voice coil motor includes a stator and a mover. The stator includes a base 1, a magnet assembly, and a housing 2. A first metal shielding mesh 3 is sleeved on the outer side of the housing 2, and a tubular silicon steel column 4 is embedded in the inner side of the housing 2. The magnet assembly includes a first magnet 8 and a second magnet 5. An aluminum annular short-circuit ring 9 is sleeved on the outer side of the first magnet 8. A groove matching the aluminum annular short-circuit ring 9 is provided on the inner side of the tubular silicon steel column 4. The first magnet 8 is fixedly connected to the inner side of the tubular silicon steel column 4 so that the aluminum annular short-circuit ring 9 is embedded in the groove. The second magnet 5 is fixedly connected to the middle of the base 1. The housing 2 is snapped into the base 1 so that the second magnet 5 is embedded in the first magnet 8. The mover includes a conductive coil 6, which is embedded in the gap between the first magnet 8 and the second magnet 5.

[0021] In this embodiment, the high permeability of the tubular silicon steel column 4 is used to absorb the external low-frequency magnetic field. When the motor is running, the leakage magnetic field passes through the aluminum ring and induces eddy currents. The reverse magnetic field generated by the eddy current cancels the leakage magnetic field, thereby reducing the leakage magnetic field. Furthermore, the first metal shielding mesh 3 and the outer shell 2 form a double-layer shielding structure, which further improves the shielding effectiveness against low-frequency magnetic fields.

[0022] Specifically, the base 1 is made of a metal material with certain strength and rigidity, such as aluminum alloy or steel, to support the entire stator structure; the first magnet 8 is made of high-performance permanent magnet material, such as neodymium iron boron magnet, to provide the required magnetic field strength, and the first magnet 8 is processed into a ring with an inner diameter that matches the tubular silicon steel column 4; the second magnet 5 is also made of neodymium iron boron magnet and processed into a cylindrical shape that matches the inner diameter of the first magnet 8; the outer shell 2 is made of a metal material with good conductivity and certain mechanical strength, such as aluminum or copper; the first metal shielding mesh 3 is made of metal braided mesh, such as copper mesh or stainless steel mesh; the tubular silicon steel column 4 is made of silicon steel material with high magnetic permeability and is made into a tubular shape through drawing or winding processes; the aluminum annular short-circuit ring 9 is made of pure aluminum or aluminum alloy material and is processed into an annular shape that matches the outer diameter of the first magnet 8; the conductive coil 6 is made of enameled wire, and the appropriate wire diameter and number of turns are selected according to the power, current and other parameters of the motor.

[0023] The specific assembly steps are as follows: First, fit the aluminum annular short-circuit ring 9 onto the outside of the first magnet 8, ensuring a tight fit. This can be achieved using glue or mechanical fixation. Next, fit the inside of the first magnet 8 tightly against the outside of the tubular silicon steel column 4. The inner side of the tubular silicon steel column 4 has a groove that matches the aluminum annular short-circuit ring 9. Fit the tubular silicon steel column 4 onto the first magnet 8, and insert the aluminum annular short-circuit ring 9 into the groove. Fix the two together using glue or other fixing methods to form a single assembly. Finally, install the second magnet 5 into the mounting hole in the middle of the base 1. Ensure the second magnet 5 is securely installed; snap the outer shell 2, which is embedded in the tubular silicon steel column 4, to the base 1 so that the second magnet 5 is inserted into the first magnet 8; tightly fit the cut first metal shielding mesh 3 onto the outside of the outer shell 2, and fix the shielding mesh to the outer shell 2 using screws, clips, or welding to form a double-layer shielding structure; carefully embed the wound and insulated conductive coil 6 into the gap between the first magnet 8 and the second magnet 5, ensuring that the coil can move freely in the magnetic field and maintain an appropriate gap with the magnet assembly to avoid mutual friction.

[0024] Preferably, the outer shell 2 is made of conductive metal to further enhance the shielding effect.

[0025] Preferably, a second metal shielding mesh 7 is provided on the outside of the conductive coil 6. The second metal shielding mesh 7 is electrically connected to the outer shell 2. The second metal shielding mesh 7 can shield the high-frequency electromagnetic radiation generated when the coil is energized (such as 10kHz-1MHz interference from the switching power supply). The second metal shielding mesh 7 is a flexible mesh that can expand and contract with the coil.

[0026] Preferably, the first metal shielding mesh 3 is a brass mesh tube, which is electrically connected to the outer shell 2 for grounding, and has a good shielding effect.

[0027] Preferably, the surface of the brass mesh tube is provided with heat dissipation fins to increase the heat dissipation area and facilitate heat dissipation. It can be formed by stamping, welding, or injection molding.

[0028] Preferably, the second metal shielding mesh 7 is a copper-nickel alloy mesh, which is electrically connected to the outer shell 2 for grounding, and has a good shielding effect.

[0029] Optionally, the base 1 has a slot at one end, and the bottom of the outer shell 2 has a locking block. The outer shell 2 is inserted into the slot by the locking block and engages with the base 1, so that the outer shell 2 can be quickly removed for easy maintenance.

[0030] Preferably, a 0.5mm air gap is reserved between the tubular silicon steel column 4 and the first magnet 8 to avoid direct contact between the two (metal contact will form a magnetic path, causing external interference to be conducted to the magnetic cylinder through the shield). Alternatively, they can be isolated by an insulating coating or an insulating medium. A 1mm gap is maintained between the second metal shield 7 of the conductive coil 6 and the first magnet 8. There is no friction between the two when the coil moves, which prevents mechanical wear and avoids interference coupling (such as electrostatic conduction) caused by contact.

[0031] Specifically, the working principle and usage process of this utility model are as follows: By utilizing the high magnetic permeability of the tubular silicon steel column 4 to absorb the external low-frequency magnetic field, and through the aluminum annular short-circuit ring 9, when the motor is running, the leakage magnetic field passes through the aluminum ring and induces eddy currents. The reverse magnetic field generated by the eddy currents cancels the leakage magnetic field (similar to the leakage magnetic field suppression principle of a transformer), thereby reducing the leakage magnetic field. Then, the first metal shielding mesh 3 and the outer shell 2 form a double-layer shielding structure, further improving the shielding effectiveness against low-frequency magnetic fields.

[0032] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. An anti-interference shielded voice coil motor, comprising a stator and a mover, characterized in that, The stator includes a base (1), a magnet assembly and a housing (2). The outer side of the housing (2) is fitted with a first metal shielding mesh (3). The inner side of the housing (2) is fitted with a tubular silicon steel column (4). The magnet assembly includes a first magnet (8) and a second magnet (5). The outer side of the first magnet (8) is fitted with an aluminum annular short-circuit ring (9). The inner side of the tubular silicon steel column (4) is provided with a groove that matches the aluminum annular short-circuit ring (9). The first magnet (8) is fixedly connected to the inner side of the tubular silicon steel column (4) so ​​that the aluminum annular short-circuit ring (9) is embedded in the groove. The second magnet (5) is fixedly connected to the middle of the base (1). The housing (2) is snapped into the base (1) so that the second magnet (5) is embedded in the first magnet (8). The mover includes a conductive coil (6). The conductive coil (6) is embedded in the gap between the first magnet (8) and the second magnet (5).

2. The anti-interference shielded voice coil motor according to claim 1, characterized in that, The outer shell (2) is made of conductive metal.

3. The anti-interference shielded voice coil motor according to claim 2, characterized in that, The conductive coil (6) is fitted with a second metal shielding mesh (7) on its outer side, and the second metal shielding mesh (7) is electrically connected to the outer shell (2).

4. The anti-interference shielded voice coil motor according to claim 1, characterized in that, The first metal shielding mesh (3) is a brass mesh tube.

5. The anti-interference shielded voice coil motor according to claim 4, characterized in that, The surface of the brass mesh tube is provided with heat dissipation fins.

6. The anti-interference shielded voice coil motor according to claim 3, characterized in that, The second metal shielding mesh (7) is a copper-nickel alloy mesh.

Images