Permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and driving

Abstract

The present invention relates to the field of vibration measurement technology, and in particular to a permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and driving, comprising an electromagnetic driving component and a moving component; the electromagnetic driving component comprises a cylindrical lower magnetic yoke, and a ring-shaped permanent magnet arranged inside the lower magnetic yoke; the inner side of the lower magnetic yoke and the inner side and lower side of the permanent magnet enclose a moving cavity; a central magnetic yoke is installed on the lower magnetic yoke and inside the moving cavity; an air gap is arranged between the central magnetic yoke and the permanent magnet; the moving component comprises a work surface located on the upper side of the central magnetic yoke, a coil frame is arranged on a side of the work surface close to the central magnetic yoke, and the coil frame is slidably sleeved on the outer side of the central magnetic yoke; the outer wall of the coil frame is wound with a DC coil and an excitation coil. By adopting the above scheme, the difficulty of assembling the moving component is reduced to the greatest extent, the dead weight of the moving component is reduced, and the assembly accuracy and driving ability of the electromagnetic actuator are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of vibration measurement, in particular to a centripetal excitation cylindrical electromagnetic actuator with permanent magnets and combined guidance and driving. Background Art

[0002] Electromagnetic actuators have very wide applications in the field of vibration and are core components of equipment such as electromagnetic vibration tables and voice coil motors. In recent years, related research in major fields such as aerospace, building bridges, and earthquake prevention and disaster reduction has placed increasingly higher requirements on the performance of electromagnetic actuators. The drive and guide mechanisms of traditional electromagnetic actuators are separated, which will inevitably introduce errors during assembly, increase the distortion of the electromagnetic drive waveform, and cause lateral vibration of the moving parts; at the same time, the separated drive and guide mechanisms require larger moving parts, and large-sized moving parts have a large mass, which will weaken the electromagnetic drive capability and is not conducive to the miniaturization of equipment. Therefore, achieving high assembly accuracy and lightweight moving parts of electromagnetic actuators through simple and reliable design methods is the key to improving their performance.

[0003] Patent No. ZL201510236217.7 discloses a long permanent magnet tube centripetal excitation cylindrical low-frequency vibration calibration platform with magnetic field tracking compensation. It is proposed to coaxially assemble the permanent magnet tube inside the long cylindrical outer magnetic yoke by bonding for excitation. The polarity of the magnetic poles on the inner surface of the permanent magnet tube is the same. The magnetic yoke forms a closed magnetic circuit to generate a highly uniform magnetic field distribution in the air gap. The central magnetic yoke is evenly wound with compensation coils to form a compensation magnetic field to synchronously track and compensate the influence of the armature reaction, and the static pressure air floating guide technology is used to ensure the motion guide accuracy.

[0004] Patent No. CN201811332560.1 discloses a vibration table. It generates a magnetic field through a magnetic circuit device, and fixes an air bearing on the periphery of the dynamic coil frame to reduce lateral disturbances. The DC coil and the excitation coil are radially wound around the outer peripheral wall of the dynamic coil frame. The DC coil is located in the linear magnetic field area. The DC excitation is used to position the dynamic coil at a position where the DC Ampere force is equal to its gravity to offset the gravity and determine the zero position. The excitation coil is located in the uniform magnetic field area and is excited by AC to generate standard vibration.

[0005] The salient features of the above technical solution are: the guide device is separated from the drive structure, and during the assembly process, it is necessary to strictly ensure that the electromagnetic drive structure and the guide device are fixed and installed in parallel to the axis. The assembly accuracy is difficult to ensure, which can easily cause the vibration waveform to be distorted and produce lateral vibration; additional mechanical parts are required to connect the guide and drive mechanisms, which is not conducive to the miniaturization and lightweight design of moving parts, and seriously restricts the load capacity of the electromagnetic actuator. For low-frequency electromagnetic vibration tables that often calibrate large vibration sensors, load capacity is particularly important; and patent CN201811332560.1 places the DC coil in a linear magnetic field region that is only approximately linear, and its nonlinearity will bring harmonic distortion to the vibration waveform.

[0006] In summary, through the innovation of the structure and principle of the electromagnetic vibration calibration table, a permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and driving is provided. Summary of the invention

[0007] 1. Technical issues to be resolved

[0008] In view of the deficiencies in the prior art, the present invention provides a permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and drive, which greatly reduces the difficulty of assembling moving parts, reduces the dead weight of moving parts, and effectively improves the assembly accuracy and driving ability of the electromagnetic actuator.

[0009] (II) Technical solution

[0010] To achieve the above-mentioned purpose, an embodiment of the present application provides a guide and drive composite permanent magnet centripetal excitation cylindrical electromagnetic actuator, comprising an electromagnetic drive component and a moving component; the electromagnetic drive component comprises a cylindrical lower magnetic yoke and a ring-shaped permanent magnet arranged on the inner side of the lower magnetic yoke; the inner side of the lower magnetic yoke and the lower side of the permanent magnet enclose a moving cavity; a central magnetic yoke is installed on the lower magnetic yoke and located on the inner side of the moving cavity; an air gap is arranged between the central magnetic yoke and the permanent magnet; the moving component comprises a work table located on the upper side of the central magnetic yoke, and a coil frame is arranged on a side of the work table close to the central magnetic yoke, the coil frame is ring-shaped and slidably sleeved on the outer side of the central magnetic yoke; a DC coil and an excitation coil are wound around the outer wall of the coil frame, a fixed DC current is passed into the DC coil to generate an Ampere force opposite to the gravity direction of the moving component; a controllable driving current is passed into the excitation coil to generate an electromagnetic driving force.

[0011] Preferably, a static pressure air floating structure is provided on the coil frame, and the static pressure air floating structure controls the formation of a static pressure air film between the coil frame and the central magnetic yoke.

[0012] Preferably, the static pressure air flotation structure includes a cylindrical cavity-type air chamber opened in the coil frame, and an air outlet is opened on a side of the coil frame close to the center magnetic yoke, the air outlet is connected to the air chamber, and the air outlet is evenly distributed on the inner surface of the coil frame; an air inlet is opened on the outer surface of the coil frame away from the center magnetic yoke, the air inlet is connected to the air chamber, and the air inlet is connected to an air supply source.

[0013] Preferably, the outer side surface of the permanent magnet abuts the inner surface of the lower magnetic yoke; a mounting frame for fixing the central magnetic yoke and supporting the permanent magnet is provided in the motion cavity; the mounting frame is annular, and an annular mounting groove is provided on the mounting frame; a mounting hole is provided on the mounting frame and at the bottom of the mounting groove; the inner side wall of the mounting frame abuts the central magnetic yoke, the upper side abuts the permanent magnet, and the lower side of the mounting frame is detachably connected to the lower magnetic yoke.

[0014] Preferably, a sliding guide rail or a rolling guide rail is provided between the coil frame and the central magnetic yoke.

[0015] Preferably, the permanent magnet includes one permanent magnet or a plurality of permanent magnets bonded to each other.

[0016] Preferably, the DC coil and the excitation coil are located in the air gap and in a region where the magnetic field is uniformly distributed; the DC coil and the excitation coil can be connected to each other.

[0017] Preferably, the fixed-size direct current is calculated by the following formula: DC =mg / (BL); in the formula, I DC is the magnitude of the DC current passed through the DC coil, m is the mass of the moving parts and related components fixed on the work surface, g is the acceleration of gravity, B is the average magnetic induction intensity distributed in the air gap, and L is the length of the DC coil.

[0018] (III) Beneficial effects

[0019] The present invention provides a permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and driving. By arranging a lower yoke, a permanent magnet, a central yoke and a mounting assembly, the lower yoke, the permanent magnet and the central yoke can be quickly and coaxially installed. At the same time, by arranging a static pressure air floating structure and an integrated design of the central yoke, the difficulty of assembling moving parts is reduced to the greatest extent, the dead weight of the moving parts is reduced, and the assembly accuracy and driving ability of the electromagnetic actuator can be effectively improved. In addition, the DC coil is located in the area with uniform magnetic field distribution, avoiding the introduction of interference.

[0020] The specific beneficial effects are as follows:

[0021] (1) The magnetic circuit structure of the permanent magnet centripetal excitation adopted in the present invention can generate a stronger magnetic induction intensity in the air gap, which is suitable for occasions with high requirements for electromagnetic driving force.

[0022] (2) The present invention completes the design of an electromagnetic actuator with integrated guidance and drive by processing the central magnetic yoke into the form of a guide shaft and making the coil skeleton into a sliding mechanism, thereby achieving high assembly accuracy and improving the motion accuracy of the electromagnetic actuator. The moving part is mounted on the guide shaft formed by the central magnetic yoke as a sliding mechanism, and the guidance and drive are integrated through a static pressure air floating structure, a sliding guide rail or a rolling guide rail, ensuring that the axial direction of the moving part and the electromagnetic drive structure are completely parallel, achieving high assembly accuracy, avoiding lateral vibration caused by assembly errors, and effectively improving the waveform accuracy of the electromagnetic drive.

[0023] (3) The present invention achieves the miniaturization design goal of the electromagnetic actuator and can significantly improve its load capacity. The electromagnetic actuator with integrated guidance and drive does not require an additional guidance mechanism, has a compact structure, and makes the device more miniaturized, which is convenient for the installation and transportation of the equipment. There is no additional guidance mechanism to occupy additional space, which greatly reduces the size of the moving parts, achieves lightweight moving parts in structure, and effectively improves the load capacity of the electromagnetic actuator.

[0024] (4) The present invention can avoid the problem of the DC coil being subjected to nonlinear electromagnetic force outside the air gap and generating vibration harmonics. The DC coil is placed in the area where the air gap magnetic field is evenly distributed, and a fixed amount of DC current is passed through it so that the DC coil is subjected to an Ampere force equal to the gravity of the moving part. Active positive stiffness support is achieved by passing a control quantity based on displacement feedback into the excitation coil, thereby avoiding the DC coil being subjected to nonlinear electromagnetic force outside the air gap and generating harmonic interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a permanent magnet centripetal excitation cylindrical electromagnetic actuator for guidance and driving;

[0026] Figure 2 A cross-sectional view of a permanent magnet centripetal excitation cylindrical electromagnetic actuator for guiding and driving a composite;

[0027] Figure 3 A cross-sectional view of a protruding mounting frame in a permanent magnet centripetal excitation cylindrical electromagnetic actuator for guiding and driving a composite;

[0028] Figure 4 A schematic diagram of a protruding mounting frame in a permanent magnet centripetal excitation cylindrical electromagnetic actuator for guiding and driving a composite;

[0029] Figure 5 A schematic diagram of the magnetic pole distribution and magnetic circuit in a permanent magnet centripetal excitation cylindrical electromagnetic actuator for guidance and driving;

[0030] Figure 6 A cross-sectional view of a protruding moving part in a permanent magnet centripetal excitation cylindrical electromagnetic actuator for guiding and driving a composite;

[0031] Figure 7 Schematic diagram of the protruding static pressure air-floating structure in the permanent magnet centripetal excitation cylindrical electromagnetic actuator for guidance and driving;

[0032] Figure 8 Schematic diagram of the protruding air inlet hole position in the permanent magnet centripetal excitation cylindrical electromagnetic actuator for guidance and driving.

[0033] Markings in the accompanying drawings:

[0034] 100, electromagnetic drive component; 110, lower magnetic yoke; 120, permanent magnet; 130, center magnetic yoke; 140, motion cavity; 160, air gap; 170, mounting frame; 170a, mounting groove; 170b, mounting hole;

[0035] 200, moving parts; 210, work surface; 220, coil frame; 230, DC coil; 240, excitation coil; 250, static pressure air floating structure; 251, air chamber; 252, air outlet; 253, air inlet. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0037] Example

[0038] The present invention provides a permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and driving, see Figure 1-Figure 8 , including an electromagnetic driving component 100 and a moving component 200.

[0039] The electromagnetic driving component 100 includes a cylindrical lower magnetic yoke 110, and a ring-shaped permanent magnet 120 disposed inside the lower magnetic yoke 110; the inner side of the lower magnetic yoke 110 and the lower side of the permanent magnet 120 enclose a motion cavity 140; a central magnetic yoke 130 is mounted on the lower magnetic yoke 110 and inside the motion cavity 140; an air gap 160 is disposed between the central magnetic yoke 130 and the permanent magnet 120. In this embodiment, the width of the air gap 160 is 10 mm, and a highly uniform magnetic induction intensity distribution is formed therein.

[0040] Furthermore, the lower magnetic yoke 110 , the permanent magnet 120 , and the central magnetic yoke 130 are coaxially arranged; and the central magnetic yoke 130 is located at the center of the lower magnetic yoke 110 .

[0041] The outer side surface of the permanent magnet 120 abuts against the inner surface of the lower magnetic yoke 110; a mounting frame 170 is provided in the motion cavity 140 to fix the central magnetic yoke 130 and support the permanent magnet 120; the mounting frame 170 is annular, and an annular mounting groove 170a is provided on the mounting frame 170, and a mounting hole 170b is provided at the bottom of the mounting groove 170a; during installation, the mounting frame 170 can be connected and fixed to the lower magnetic yoke 110 by passing a bolt through the mounting hole 170b. The inner side wall of the mounting frame 170 abuts against the central magnetic yoke 130, and the upper side abuts against the permanent magnet 120, and the lower side of the mounting frame 170 can be detachably connected to the lower magnetic yoke 110. By providing the mounting frame 170, the upper permanent magnet 120 can be supported and the central magnetic yoke 130 can be fixed. Among them, the above-mentioned detachable connection and fixation can be fixed by bolt connection or other connection methods, which are not limited here.

[0042] It should be noted that, in this embodiment, the mounting frame 170 is made of non-magnetic conductive material, such as aluminum alloy.

[0043] The permanent magnet 120 includes one permanent magnet 120 or a plurality of permanent magnets 120 bonded to each other.

[0044] Specifically, the permanent magnet 120 can be made of a strong magnetic permanent magnet made of NdFeB, and the residual magnetic strength of the NdFeB material used is 1.17T and the coercive force is 890kA / m. The lower magnetic yoke 110 and the center magnetic yoke 130 are both made of high magnetic permeability electrical pure iron material DT4C, with a maximum relative magnetic permeability of 12000 and a saturation magnetic flux of 2.5T.

[0045] The path of the magnetic lines of force formed by the permanent magnet 120 excitation to form the main magnetic circuit is as follows: Figure 5 As shown, it starts from the N pole of the permanent magnet 120, passes through the lower magnetic yoke 110, the center magnetic yoke 130, the air gap 160 in sequence, and then returns to the S pole of the permanent magnet 120 to form a closed magnetic circuit.

[0046] The material of the moving part 200 is ceramic, aluminum alloy or beryllium. Specifically, it includes a work surface 210 located on the upper side of the central magnetic yoke 130, and a coil frame 220 is arranged on the side of the work surface 210 close to the central magnetic yoke 130. The coil frame 220 is annular and slidably sleeved on the outer side of the central magnetic yoke 130; a DC coil 230 and an excitation coil 240 are wound around the outer wall of the coil frame 220, and a fixed DC current is passed into the DC coil 230 to generate an Ampere force opposite to the gravity direction of the moving part 200; and a controllable driving current is passed into the excitation coil 240 to generate an electromagnetic driving force.

[0047] The moving part 200 is made of aluminum alloy and is cylindrical in shape.

[0048] The DC coil 230 and the excitation coil 240 are formed by winding the insulated copper enameled wire on the outer surface of the coil frame 220, with an O-shaped cross section and a thickness of 3mm. The maximum current density is 5A / mm 2 After the magnetic circuit structure of the electromagnetic vibration table is assembled, the DC coil 230 , the excitation coil 240 and the coil frame 220 are located in the air gap 160 .

[0049] The fixed DC current is calculated by the following formula: DC =mg / (BL). In the formula, I DC is the magnitude of the DC current passed through the DC coil 230, m is the mass of the moving part 200 and the related components fixed on the work surface 210, g is the acceleration of gravity, B is the average magnetic induction intensity distributed in the air gap 160, and L is the length of the DC coil 230.

[0050] The DC coil 230 and the excitation coil 240 are located in the air gap 160 and in the area where the magnetic field is uniformly distributed; when the DC coil 230 does not need to offset the gravity of the moving part 200, the DC coil 230 and the excitation coil 240 can be connected to each other and a driving current can be passed to achieve a large electromagnetic driving force.

[0051] After the control signal is passed into the excitation coil 240 and amplified by the power amplifier, the effective value of the power current is up to tens of amperes. According to the electromagnetic field theory, the excitation coil 240 energized in the magnetic field is subjected to the vertical Ampere force, thereby outputting a precisely controllable electromagnetic driving force. The magnitude and direction of the electromagnetic driving force can be precisely controlled by controlling the magnitude and direction of the current passed. If the control signal adopts a standard sinusoidal electrical signal, the moving part 200 will generate a standard sinusoidal vibration along the axial direction under the action of the electromagnetic driving force.

[0052] In one embodiment, a static pressure air floating structure 250 is provided on the coil frame 220, and the static pressure air floating structure 250 controls the formation of a static pressure air film between the coil frame 220 and the central magnetic yoke 130. The static pressure air floating structure 250 is used to generate vertical standard vibration, and in this embodiment, the maximum stroke is 10mm.

[0053] The static pressure air floating structure 250 includes a cylindrical cavity air chamber 251 opened in the coil frame 220, and a side of the coil frame 220 close to the central magnetic yoke 130 is provided with an air outlet 252, the air outlet 252 is connected to the air chamber 251, and the air outlet 252 is evenly distributed on the inner surface of the coil frame 220. The outer surface of the coil frame 220 away from the central magnetic yoke 130 is provided with an air inlet 253, the air inlet 253 is connected to the air chamber 251, and the air inlet 253 is connected to the air supply source. Specifically, the diameter of the air hole can be 2mm.

[0054] In this embodiment, the lower cross-section of the coil frame 220 is annular and has a diameter of 80 mm. The static pressure air floating structure 250 is mounted on the central magnetic yoke 130 through the coil frame 220, so that the static pressure air floating guide rail and the axial direction of the electromagnetic drive structure are completely parallel, ensuring assembly accuracy; during the assembly process, the inner surface of the coil frame 220 and the size of the central magnetic yoke 130 are matched, so that the coil frame 220 and the central magnetic yoke 130 can be easily assembled, and the assembly has high reliability.

[0055] In another embodiment, a sliding guide rail or a rolling guide rail may be further provided between the coil frame 220 and the central magnetic yoke 130 .

[0056] The present invention provides a permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and driving. By setting a lower magnetic yoke 110, a permanent magnet 120, a central magnetic yoke 130 and a mounting frame 170, the lower magnetic yoke 110, the permanent magnet 120 and the central magnetic yoke 130 can be quickly and coaxially installed. At the same time, by setting a static pressure air floating structure 250 and an integrated design of the central magnetic yoke 130, the difficulty of assembling the moving part 200 is reduced to the greatest extent, the dead weight of the moving part 200 is reduced, and the assembly accuracy and driving ability of the electromagnetic actuator can be effectively improved. In addition, the DC coil 230 is located in the area with uniform magnetic field distribution to avoid introducing interference.

[0057] The specific beneficial effects are as follows:

[0058] (1) The magnetic circuit structure of the centripetal excitation of the permanent magnet 120 adopted in the present invention can generate a stronger magnetic induction intensity in the air gap 160, which is suitable for occasions with high requirements for electromagnetic driving force.

[0059] (2) The present invention completes the design of an electromagnetic actuator with integrated guidance and drive by processing the central magnetic yoke 130 into the form of a guide shaft and making the coil frame 220 into a sliding mechanism, achieving high assembly accuracy and improving the motion accuracy of the electromagnetic actuator. The moving component 200 is mounted on the guide shaft formed by the central magnetic yoke 130 as a sliding mechanism, and the integration of guidance and drive is achieved through the static pressure air floating structure 250, the sliding guide form or the rolling guide form, ensuring that the moving component 200 is completely parallel to the axial direction of the electromagnetic drive structure, achieving high assembly accuracy, avoiding lateral vibration caused by assembly errors, and effectively improving the waveform accuracy of the electromagnetic drive.

[0060] (3) The present invention achieves the miniaturization design goal of the electromagnetic actuator and can significantly improve its load capacity. The electromagnetic actuator with integrated guidance and drive does not require an additional guidance mechanism and has a compact structure, making the device more miniaturized and facilitating the installation and transportation of the equipment. The absence of an additional guidance mechanism to occupy additional space greatly reduces the size of the moving part 200, achieves lightweighting of the moving part 200 in terms of structure, and effectively improves the load capacity of the electromagnetic actuator.

[0061] (4) The present invention can avoid the problem that the DC coil 230 is subjected to nonlinear electromagnetic force outside the air gap 160 and generates vibration harmonics. The DC coil 230 is placed in the uniform magnetic field distribution area of ​​the air gap 160, and a fixed amount of DC power is passed to make the DC coil 230 subjected to an Ampere force equal to the gravity of the moving part 200. Active positive stiffness support is achieved by passing a control quantity based on displacement feedback superimposed in the excitation coil 240, thereby avoiding the DC coil 230 being subjected to nonlinear electromagnetic force outside the air gap 160 and generating harmonic interference.

[0062] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium, or the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0064] The above-mentioned embodiments only express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A permanent magnet centripetal excitation cylindrical electromagnetic actuator with combined guidance and driving, Features: It comprises an electromagnetic driving component (100) and a moving component (200); The electromagnetic drive component (100) comprises a cylindrical lower magnetic yoke (110), and a ring-shaped permanent magnet (120) arranged inside the lower magnetic yoke (110); the inner side of the lower magnetic yoke (110) and the lower side of the permanent magnet (120) enclose a motion cavity (140); a central magnetic yoke (130) is installed on the lower magnetic yoke (110) and located inside the motion cavity (140); an air gap (160) is arranged between the central magnetic yoke (130) and the permanent magnet (120); The moving component (200) comprises a work surface (210) located on the upper side of the central magnetic yoke (130); a coil frame (220) is arranged on a side of the work surface (210) close to the central magnetic yoke (130); the coil frame (220) is annular and slidably sleeved on the outer side of the central magnetic yoke (130); a DC coil (230) and an excitation coil (240) are wound around the outer wall of the coil frame (220); a fixed DC current is passed through the DC coil (230) to generate an Ampere force opposite to the gravity direction of the moving component (200); a controllable driving current is passed through the excitation coil (240) to generate an electromagnetic driving force; A static pressure air floating structure (250) is provided on the coil frame (220), and the static pressure air floating structure (250) controls the formation of a static pressure air film between the coil frame (220) and the central magnetic yoke (130); The static pressure air floating structure (250) comprises a cylindrical cavity-type air chamber (251) opened in the coil frame (220), and a side surface of the coil frame (220) close to the central magnetic yoke (130) is provided with an air outlet hole (252), the air outlet hole (252) is connected to the air chamber (251), and the air outlet holes (252) are evenly distributed on the inner surface of the coil frame (220); An air inlet hole (253) is provided on the outer surface of the coil frame (220) away from the central magnetic yoke (130), and the air inlet hole (253) is connected to the air chamber (251), and the air inlet hole (253) is connected to an air supply source.

2. The centripetal excitation cylindrical electromagnetic actuator with permanent magnets for guiding and driving according to claim 1, Features: The lower magnetic yoke (110), the permanent magnet (120), and the central magnetic yoke (130) are coaxially arranged; and the central magnetic yoke (130) is located at the center of the lower magnetic yoke (110).

3. The centripetal excitation cylindrical electromagnetic actuator with permanent magnets for guiding and driving according to claim 1, Features: The outer side surface of the permanent magnet (120) abuts against the inner surface of the lower magnetic yoke (110); The motion cavity (140) is provided with a mounting frame (170) for fixing the central magnetic yoke (130) and supporting the permanent magnet (120); the mounting frame (170) is annular, and an annular mounting groove (170a) is provided on the mounting frame (170); a mounting hole (170b) is provided on the mounting frame (170) and located at the bottom of the mounting groove (170a); the inner side wall of the mounting frame (170) abuts against the central magnetic yoke (130), the upper side abuts against the permanent magnet (120), and the lower side of the mounting frame (170) is detachably connected to the lower magnetic yoke (110).

4. The centripetal excitation cylindrical electromagnetic actuator with permanent magnets for guiding and driving according to claim 1, Features: A sliding guide rail or a rolling guide rail is provided between the coil frame (220) and the central magnetic yoke (130).

5. The centripetal excitation cylindrical electromagnetic actuator with permanent magnets for guiding and driving according to claim 1, Features: The permanent magnet (120) includes one permanent magnet (120) or a plurality of permanent magnets (120) bonded to each other.

6. The centripetal excitation cylindrical electromagnetic actuator with permanent magnets for guiding and driving according to claim 1, Features: The DC coil (230) and the excitation coil (240) are located in the air gap (160) and in a region where the magnetic field is evenly distributed; The DC coil (230) and the excitation coil (240) are connected to each other or not connected.

7. The centripetal excitation cylindrical electromagnetic actuator with permanent magnets for guiding and driving according to claim 1, Features: The fixed DC current is calculated by the following formula: DC =mg / (BL); in the formula, I DC is the magnitude of the direct current passed through the DC coil (230), m is the mass of the moving part (200) and related components fixed on the work surface (210), g is the acceleration of gravity, B is the average magnetic induction intensity distributed in the air gap (160), and L is the length of the DC coil (230).

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