Stable Output Horizontal Axial Angle Vibration Device

Abstract

The present invention discloses a device for stably outputting horizontal axial angular vibration, which comprises a base; a moving component, the base; the moving component includes a tabletop and a main shaft, and the axis of the main shaft is horizontally arranged; a first driving component, which includes a first moving coil assembly installed on the moving component and associated with the main shaft and a first magnetic circuit assembly installed on the base and cooperating with the first moving coil assembly; a centroid adjusting component, which is associated with the tabletop and / or the main shaft to adjust the overall centroid of the moving component to the axis of the main shaft. In the present invention, the main shaft is horizontally placed and driven by the first driving component, so that the tabletop for placing the test equipment makes angular vibration around a rotating shaft parallel to it, realizing the excitation of the test equipment with a sensitive rotating shaft parallel to the installation surface; and a centroid adjusting component is provided to adjust the centroid deviation caused by installing the test equipment and the like on the tabletop.

Description

Technical Field

[0001] The present invention belongs to the technical field of angular vibration tables, and in particular relates to a device for stably outputting horizontal axial angular vibration. Background Art

[0002] With the development of modern science and technology, angular vibration sensors are more and more widely used in various fields of national economic life, such as deep sea exploration, resource exploration, aerospace, medical devices, automotive industry, household appliances, etc. Angular vibration sensors need to be calibrated before leaving the factory and calibrated after being used for a certain period of time or repaired. As one of the key devices for dynamic performance calibration or calibration of angular vibration sensors, angular vibration tables are attracting more and more attention. In addition, angular vibration tables can also be used for angular vibration environment tests of various products.

[0003] Traditional angular vibration tables adopt DC torque motors as driving elements. The motor torque output shaft is fixedly connected to the main shaft of the moving part. When an alternating current is applied to the DC torque motor, the alternating torque generated by the motor acts on the moving part, thereby causing the moving part to generate angular vibration. Due to the influence of the motor time constant, the working frequency range of this kind of angular vibration table using a DC torque motor is generally below 100Hz. Moreover, due to the large friction of mechanical bearings and the non-uniform magnetic field inside the motor, even if a brushless DC torque motor is used, the distortion of the angular vibration waveform output by the vibration table is relatively large.

[0004] In recent years, in order to overcome the shortcomings of the above-mentioned angular vibration tables with motors as driving elements, a non-motor-driven coil-excitation-driven angular vibration table has been gradually proposed. For example, Chinese Patent No. CN200610099078.9 discloses a non-motor-driven electric angular vibration table. The excitation system of the angular vibration table consists of a base made of pure iron for electrical engineering, the outer wall of the magnetic core, and a magnetic yoke cooperating with the excitation coil. The moving coil skeleton is evenly distributed with wire grooves. The driving wire is tightly wrapped with insulating adhesive paper. After being inserted into the wire grooves on the moving coil skeleton, it is impregnated with high-pressure paint and cured. The wire extends out at both ends of the wire groove and is welded to the braided flexible wire. The main shaft is a hollow cylinder cup structure, and its two ends are respectively connected to the moving coil and the tabletop. A rubber cylinder is sleeved outside the main shaft, and both ends of the rubber cylinder are bonded to the support seat and the tabletop with strong glue respectively. The moving coil is placed between the magnetic core and the magnetic yoke. This kind of angular vibration table generates a magnetic field by the excitation coil, passes an alternating current into the moving coil located in the air-gap magnetic field, and under the electromagnetic coupling action of the moving coil and the magnetic field, the moving coil generates an alternating torque, thereby causing the tabletop connected to the moving coil to generate angular vibration. The disadvantages of this kind of angular vibration table are as follows: 1) It is difficult to wind the moving coil, the wiring is uneven, and the process is complex; 2) The inertia of the rotating parts is large, and the working frequency range is narrow; 3) Since a rubber cylinder spring is used as the restoring spring of the driving part, the rotation angle range is limited, the angular displacement is small, and the distortion of the angular acceleration waveform is large.

[0005] An angular vibration device described in Chinese Patent CN201420503770.3 includes a housing, a table, a main shaft for driving the table to rotate, a first moving coil assembly, a magnetic circuit assembly, an air bearing, and an angular displacement sensor. When this angular vibration device works, an alternating current is passed into the coil, and an Ampere force is generated under the action of the magnetic field, so that the first moving coil assembly vibrates back and forth around the equilibrium position under the action of the Ampere force. This angular vibration device solves the problems existing in the above angular vibration table. However, the rotation axes of all the above types of angular vibration tables are perpendicular to the table surface of the angular vibration table or parallel to the acceleration of gravity.

[0006] There are two types of angular vibration sensors: one type has a sensitive rotation axis perpendicular to the mounting surface; the other type has a sensitive rotation axis parallel to the mounting surface, and the mounting surface is generally in a horizontal state. An angular vibration table with a rotation axis perpendicular to the table surface or parallel to the acceleration of gravity can only be used to calibrate an angular vibration sensor with a sensitive rotation axis perpendicular to the mounting surface. If it is used to calibrate an angular vibration sensor with a sensitive rotation axis parallel to the mounting surface, its mounting surface must be placed perpendicular to the table surface of the angular vibration table. However, this is inconsistent with its actual working state, and with the influence of additional tooling, it will bring a large calibration error. For an angular vibration sensor with a sensitive rotation axis parallel to the mounting surface, an angular vibration table with a rotation axis parallel to the table surface must be used. In addition, a product angular vibration environment test for simulating the rotational freedom in the horizontal axial direction also requires an angular vibration table with a rotation axis parallel to the table surface; at the same time, an angular vibration table with a rotation axis parallel to the table surface can also be used for dynamic calibration of a linear acceleration sensor in a gravitational field. Currently, there is no calibration angular vibration table with a rotation axis parallel to the table surface on the market. Summary of the Invention

[0007] In order to overcome the deficiencies of the prior art, the present invention provides a stable output horizontal axial angular vibration device.

[0008] A stable output horizontal axial angular vibration device includes

[0009] a base;

[0010] a moving part, including a table for placing the device under test and a main shaft connected to the table to drive the table to deflect back and forth, and the axis of the main shaft is horizontally arranged;

[0011] a first driving part, including a first moving coil assembly installed on the moving part and associated with the main shaft, and a first magnetic circuit assembly installed on the base and cooperating with the first moving coil assembly; when an alternating current is passed into the first moving coil assembly, an alternating driving torque is generated on the first moving coil assembly in the air gap magnetic field generated by the first magnetic circuit assembly, so as to drive the moving part to swing back and forth around the equilibrium position, realizing the angular vibration of the table.

[0012] The centroid adjustment component is associated with the tabletop and / or the main shaft to adjust the overall centroid of the moving part to the axis of the main shaft.

[0013] Optionally, there are at least two groups of the centroid adjustment components, and the two groups of centroid adjustment components are arranged at intervals along the length direction of the main shaft and symmetrically arranged relative to the tabletop.

[0014] Optionally, the centroid adjustment component includes a fixed balance block arranged on the tabletop, and the fixed balance block is arranged at the reverse position where the centroid of the moving part deviates.

[0015] Optionally, the centroid adjustment component further includes an adjustable balance block movably arranged on the fixed balance block.

[0016] Optionally, the adjustable balance block and the fixed balance block are fixed by a plurality of fastening bolts and nuts. A guide groove is formed on one side surface of the fixed balance block in a direction away from the tabletop, and the guide groove is a T-shaped groove. The large-diameter end of the nut can slide in the T-shaped groove, and the threaded section of the fastening bolt passes through the adjustable balance block and is connected to the nut.

[0017] Optionally, there are two groups of the first driving components, and the two groups of first driving components are symmetrically arranged at both ends of the main shaft to drive the main shaft to rotate simultaneously; the first moving coil assembly includes a first base body and at least one first coil group fixed on the surface of the first base body, and the first base body is fixedly connected to the main shaft.

[0018] Optionally, the first magnetic circuit assembly includes an inner magnetic guide seat arranged on the base, an outer magnetic guide seat arranged on the base and corresponding to the inner magnetic guide seat, an inner side magnet arranged on the inner magnetic guide seat, an outer side magnet arranged on the outer magnetic guide seat, and a first air gap formed between the inner side magnet and the outer side magnet; the first moving coil assembly is in clearance fit with the inner side magnet and the outer side magnet respectively.

[0019] Optionally, the inner side magnet and the outer side magnet have the same structure. The inner side magnet and the outer side magnet respectively enclose a circular ring area, and the circular ring area enclosed by the inner side magnet and the circular ring area enclosed by the outer side magnet are coaxially arranged, and the main shaft extends into the circular ring area; the number of the outer side magnets and the inner side magnets is equal, and the positions of the outer side magnets and the inner side magnets correspond one by one; the number of both the outer side magnets and the inner side magnets is a multiple of 2.

[0020] Optionally, positioning rings are respectively arranged on the outer peripheries of the inner side magnet and the outer side magnet, and the inner wall of the positioning ring is in contact with the outer shape of the inner side magnet and the outer side magnet; positioning grooves matched with the positioning rings are respectively arranged on the inner magnetic guide seat and the outer magnetic guide seat, and part of the positioning ring is clamped into the positioning groove.

[0021] Optionally, the stable output level axial vibration device further includes a radial air bearing and an axial air bearing. The main shaft is connected to the inner magnetic guide seat through the radial air bearing. The radial air bearing includes an air floating sleeve sleeved on the main shaft and a bearing seat matched with the air floating sleeve. A radial air film is formed between the air floating sleeve and the side wall of the main shaft. The bearing seat is installed on the inner magnetic guide seat. Axial air bearings are respectively arranged at both ends of the main shaft. The axial air bearing includes a plane air floating bearing that thrusts against the end of the main shaft, and a pressing bolt and a support plate that are matched with it. An axial air film is formed between the plane air floating bearing and the end of the main shaft. The support plate is installed on the outer magnetic guide seat.

[0022] In summary, the beneficial effects of the present invention are as follows:

[0023] 1. The main shaft of the present invention is horizontally placed and driven by the first driving component, so that the tabletop for placing the test equipment rotates around a rotation axis parallel to it to perform angular vibration, realizing the excitation of the test equipment (such as an angular vibration sensor) with a sensitive rotating shaft parallel to the installation surface, and further realizing the dynamic calibration of the angular vibration sensor with a sensitive rotating shaft parallel to the installation surface under actual installation conditions, thereby obtaining the amplitude-frequency characteristics and phase-frequency characteristics of such a sensor, so that the angular vibration device of the present invention can be used in the scenario of dynamically calibrating the angular vibration sensor with a sensitive rotating shaft parallel to the installation surface.

[0024] 2. A centroid adjustment component is provided. Due to the requirements of strength and stiffness of the tabletop, the side where the sensor to be calibrated is installed is thicker, so that the overall centroid of the moving component deviates from the rotation center. When working, the deviation of the centroid generates a moment acting on the main shaft. Furthermore, the radial force distribution of the main shaft on the air bearing is uneven. By setting the centroid adjustment component, the deviation of the centroid is compensated, and the centroid of the moving component is adjusted to the axis of the main shaft, reducing the distortion of the output motion waveform of the tabletop. Description of the Drawings

[0025] Figure 1 It is a three-dimensional view of Embodiment 1 of the present invention.

[0026] Figure 2 It is a cross-sectional view of Embodiment 1 of the present invention.

[0027] Figure 3 It is Figure 2 The enlarged view of part A in

[0028] Figure 4 It is the schematic diagram of the feedback control component in Embodiment 1 of the present invention.

[0029] Figure 5 It is a three-dimensional view of Embodiment 2 of the present invention.

[0030] Figure 6 It is Figure 5 The exploded view of

[0031] Figure 7 This is a cross-sectional view of the second embodiment of the present invention.

[0032] Figure 8 It is Figure 6 a perspective view of the centroid adjustment component in

[0033] Figure 9 It is Figure 8 a cross-sectional perspective view of

[0034] Figure 10 This is a perspective view of the third embodiment of the present invention.

[0035] Figure 11 It is Figure 10 an exploded view of

[0036] Figure 12 This is a cross-sectional view of the third embodiment of the present invention.

[0037] Figure 13 It is Figure 12 an enlarged view at position B in

[0038] Figure 14 It is Figure 12 a winding layout diagram of the second coil group in

[0039] Figure 15 It is Figure 12 a perspective view of the cooperation between the magnet and the positioning member in

[0040] Figure 16 It is Figure 12 a perspective view of the cooperation between the first and second fixing blocks and the second moving coil assembly in

[0041] Figure 17 This is a perspective view of the fourth embodiment of the present invention.

[0042] Figure 18 It is Figure 17 an exploded view of

[0043] Figure 19 This is a cross-sectional view of the fourth embodiment of the present invention. Detailed implementation manners

[0044] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0045] Embodiment 1

[0046] Refer to Figure 1 and Figure 2, A stable output horizontal axial angular vibration device 10, comprising a base 11, a moving member, a table 12, a main shaft 13 and a first driving member 20; the moving member operates under the drive of the first driving member 20, and the moving member at least comprises the table 12 and the main shaft 13; the table 12 serves as a working plane for placing test equipment, and a plurality of threaded holes 121 are evenly distributed on the surface for installing test equipment; the axis of the main shaft 13 is horizontally arranged, and the main shaft 13 rotates back and forth under the drive of the first driving member 20, and the main shaft 13 passes through the table 12 and is fixedly connected to the table 12 to drive the table 12 to swing, so that an angular motion amount will be output on the table 12 to excite the test equipment. Among them, the test equipment can be an angular vibration sensor with a sensitive rotating shaft parallel to the installation surface, or other equipment with a sensitive rotating shaft parallel to the installation surface.

[0047] In the present invention, the main shaft 13 is horizontally placed, and then the table 12 for placing the test equipment makes angular vibration around a rotating shaft parallel to it, realizing the excitation of the test equipment (such as an angular vibration sensor) with a sensitive rotating shaft parallel to the installation surface, so that the angular vibration device 10 of the present invention can be used in the scenario of dynamically calibrating an angular vibration sensor with a sensitive rotating shaft parallel to the installation surface.

[0048] Reference Figure 1 And Figure 2 , Two groups of the first driving members 20 are provided, which are respectively installed on the base 11, and the two groups of the first driving members 20 are symmetrically arranged at both ends of the main shaft, and output torque to the main shaft 13 at the same time, reducing the rotational error of the main shaft 13 and improving the driving ability of the angular vibration device 10. Of course, in other embodiments, only one group of the first driving members 20 is provided, which is associated with one end of the main shaft 13, and the other end of the main shaft 13 is directly rotatably arranged on the base 11 through a bearing 26 and is driven to rotate by one group of the first driving members 20.

[0049] Reference Figure 1 , Side plates 14 are symmetrically arranged on both sides of the base 11 for protecting the space below the table. A limiting block 141 is fixed at the top of the side plate 14, and the limiting block 141 is arranged below the table 12 and keeps an appropriate height difference from the table. By setting the limiting block, the swing range of the table is limited. Specifically, two limiting blocks are provided on each side plate.

[0050] Specifically, reference Figure 2 And Figure 3, the first driving component 20 includes a first moving coil assembly 21 associated with the main shaft 13 and a first magnetic circuit assembly 22 cooperating with the first moving coil assembly 21. During operation, an alternating current is applied to the first moving coil assembly 21, and under the action of the air-gap magnetic field generated by the first magnetic circuit assembly 22, an alternating driving torque is generated on the first moving coil assembly 21, and thus transmitted to the table 12 through the main shaft 13 to swing back and forth around the equilibrium position, realizing the angular vibration of the table 12, and the table 12 can output angular motion quantity.

[0051] Adopting such a driving method, a uniform torque is generated by the energized coil located in the uniform air-gap magnetic field and acts on the main shaft, and the angular vibration of the table is driven by the main shaft, avoiding the commutation torque pulsation and electromagnetic torque pulsation when using an ordinary motor to realize angular vibration, and the distortion degree of the output motion waveform is low.

[0052] Reference Figure 2 and Figure 3 , the first moving coil assembly 21 is set as an integral disc structure, and a step cooperating with the first moving coil assembly 21 is provided on the main shaft 13 to quickly position the first moving coil assembly 21 and limit the position of the first moving coil assembly 21 on the main shaft 13; at the same time, a retaining ring 23 is screwed on the main shaft 13, and the retaining ring 23 cooperates with the step to fix the first moving coil assembly 21.

[0053] Reference Figure 2 and Figure 3 , specifically, the first moving coil assembly 21 includes at least one first moving coil unit, and the first moving coil unit includes a disc-shaped first base body 211 and a plurality of first coil groups fixed on the surface of the first base body 211, and the first base body 211 is fixedly connected with the main shaft 13. The first coil groups of a single first moving coil unit are connected in parallel or in series. The first coil group includes an effective wire group located in the air-gap magnetic field and a connecting wire group located outside the air-gap magnetic field, the connecting wire group outside the air-gap magnetic field is concentric with the base body, and the effective wire group inside the air-gap magnetic field points to the center of the base body. The first moving coil unit used in this patent refers to Chinese Patent 201310451020.6.

[0054] Specifically, reference Figure 2 and Figure 3 , the first magnetic circuit assembly 22 includes an inner magnetic conductive seat 221, an outer magnetic conductive seat 222, an inner side magnet 223, an outer side magnet 224 and a first air gap formed between the inner side magnet 223 and the outer side magnet 224.

[0055] The inner magnetic guide seat 221 is installed on the base 11; the outer magnetic guide seat 222 is installed on the base 11 and is located on the side of the inner magnetic guide seat 221 away from the tabletop 12. A gland 15 that simultaneously presses the inner and outer magnetic guide seats is also provided on the base 11 to fix the inner and outer magnetic guide seats; the inner and outer magnetic guide seats of the two groups of first magnetic circuit components 22 cooperate with the base 11 to form a U-shaped structure; both ends of the main shaft 13 are respectively mounted on the U-shaped structure to keep the axis horizontal. Specifically, both ends of the main shaft 13 are installed on the inner magnetic guide seat 221 through radial air bearings 26.

[0056] A plurality of the inner magnetic steel 223 are arranged along the circumferential direction of the axis of the main shaft and are respectively fixed on the side wall of the inner magnetic guide seat 221 away from the tabletop 12; a plurality of the outer magnetic steel 224 are arranged along the circumferential direction of the axis of the main shaft and are respectively fixed on the side wall of the outer magnetic guide seat 222 close to the tabletop 12; the number of the inner magnetic steel 223 is equal to that of the outer magnetic steel, and the inner magnetic steel 223 and the outer magnetic steel 224 correspond one by one; the outer magnetic guide seat 222, the inner magnetic guide seat 221, the inner magnetic steel 223, the outer magnetic steel 224 and the first air gap form a closed magnetic circuit system; the effective wire groups in each first coil group in the first moving coil assembly 21 are always located in the air gap magnetic field formed between the corresponding inner magnetic steel 223 and outer magnetic steel 224, and the first moving coil assembly 21 is in clearance fit with the inner magnetic steel 223 and the outer magnetic steel 224 respectively.

[0057] The inner magnetic steel 223 and the outer magnetic steel 224 have the same structure. A plurality of the inner magnetic steel 223 enclose a circular ring area, and the outer magnetic steel 224 also encloses a circular ring area. The circular ring area of the inner magnetic steel 223 is coaxial with the circular ring area of the outer magnetic steel 224, and the main shaft 13 extends into the circular ring area.

[0058] The inner magnetic steel 223 and the outer magnetic steel 224 are respectively arranged in a tile shape; in the circumferential direction, there is a gap between adjacent magnetic steels. When the number of the outer magnetic steel 224 and the inner magnetic steel 223 changes, the number of the coil groups on the first base 211 also changes simultaneously. The number of the inner magnetic steel 223 and the outer magnetic steel 224 is a multiple of 2.

[0059] Adopting a permanent magnet type magnetic circuit structure, the excitation coil is omitted, the loss of the excitation system is reduced, the energy conversion efficiency is improved, and the magnetic circuit structure is simple, compact and reliable in operation.

[0060] Reference Figure 2 and Figure 3, positioning rings 24 are respectively arranged on the outer circumferences of the inner magnetic steel 223 and the outer magnetic steel 224. The positioning ring 24 cooperating with the inner magnetic steel 223 is connected to the inner magnetic conduction seat 221 through fasteners, and the positioning ring 24 cooperating with the outer magnetic steel 224 is connected to the outer magnetic conduction seat 222 through fasteners; the inner wall of the positioning ring 24 is in contact with the outer shapes of the inner magnetic steel 223 and the outer magnetic steel 224 to limit the magnetic steel and prevent the magnetic steel from shifting radially along the main shaft 13, ensuring the stability of the air gap magnetic field. Positioning grooves 25 cooperating with the positioning ring 24 are respectively provided on the inner magnetic conduction seat 221 and the outer magnetic conduction seat 222, and a part of the positioning ring 24 is clamped into the positioning groove 25 to limit the positioning ring 24.

[0061] Reference Figure 2 and Figure 3 , the stable output horizontal axial angular vibration device 10 further includes: a radial air bearing 26; the radial air bearing 26 is located between the main shaft 13 and the inner magnetic conduction seat 221.

[0062] Specifically, the radial air bearing 26 includes an air floating sleeve 261 sleeved on the main shaft 13 and a bearing seat 262 cooperating with the air floating sleeve 261, and the bearing seat 262 is installed on the inner magnetic conduction seat 221; the air floating sleeve 261 and the bearing seat 262 are of the prior art and their structures will not be described in detail. A radial air film is formed between the side wall of the air floating sleeve 261 and the main shaft 13, and the radial air film lifts the main shaft 13. Since the viscosity of the gas is extremely small, it can be considered that the friction is very small or there is no friction, and the main shaft realizes full air floating movement, thereby greatly reducing the influence of non-linear frictional resistance on the rotation of the main shaft, and thus reducing the distortion degree of the output motion waveform of the angular vibration device 10. In addition, the gas overflowing from the air film of the radial air bearing can also play a role in cooling the first moving coil assembly.

[0063] Reference Figure 2 and Figure 3 , the angular vibration device 10 of the present application further includes an axial air bearing, which is composed of a planar air floating bearing 28, a support plate 291 and a pressing bolt 292; planar air floating bearings 28 are respectively arranged at both ends of the main shaft 13, the support plate 291 is fixedly connected to the outer magnetic conduction seat 222, and the pressing bolt 292 is screwed to the support plate 291 for pressing the planar air floating bearing 28 against the end of the main shaft 13. Specifically, the pressing bolt 292 adopts a ball head pressing bolt to eliminate the influence of the non-coaxiality between the pressing bolt 292 and the main shaft 13, etc., so that the planar air floating bearing 28 always maintains a planar uniform air film contact with the end face of the main shaft 13. The planar air floating bearing 28 is of the prior art and its structure will not be described in detail.

[0064] In this way, an axial air film is formed between the planar air floating bearing and the end of the main shaft, reducing the axial runout of the main shaft, providing the stability of the main shaft movement, and further reducing the distortion degree of the output motion waveform of the angular vibration device 10.

[0065] Reference Figure 2 and Figure 4 In reference to [[ID=]], the feedback control of the angular vibration device 10 of the present invention is realized by a feedback control component 70.

[0066] Specifically, the feedback control component 70 includes an angular displacement sensor 71, a feedback unit 72, a signal generator 73, a subtractor 74, a PID controller 75, and a power amplifier 76; the angular displacement sensor is composed of a circular grating 31 and a reading head 61; the circular grating 31 is installed on a retaining ring 23 at one end of the main shaft 13 through a fastener, and the reading head 61 is installed on an outer magnetic guide seat 222 on the side corresponding to the circular grating 31 through a reading head mounting block 62. The circular grating 31 and the reading head 61 are existing products, and their structures will not be elaborated here. The reading head 61 cooperates with the circular grating 31 to detect the angular displacement signal θ of the rotation of the main shaft 13 and the table 12; this angular displacement signal is input into the feedback unit, and the feedback unit amplifies the input signal to obtain a first output signal, first differentiates the input signal and then amplifies it to obtain a second output signal, and then superimposes the first output signal and the second output signal to obtain the output signal of the feedback unit; the output signal of the feedback unit and the standard signal output by the signal generator are subtracted by the subtractor to obtain a deviation signal, and then the deviation signal is processed by a PID regulator and output to the power amplifier to drive the movement of the main shaft 13 and the table 12, thereby realizing the feedback control of the angular vibration device 10, and improving and reducing the distortion degree of the output motion quantity waveform of the angular vibration device.

[0067] Reference Figure 2 and Figure 3 In reference to [[ID=]], in order to compensate for the centroid offset generated after adding the circular grating 31 to one end of the main shaft 13, a counterweight ring 32 is provided at the other end of the main shaft 13 away from the circular grating 31. The mass of the counterweight ring 32 is the same as that of the circular grating 31, and the counterweight ring 32 and the circular grating 31 are symmetrically arranged with respect to the main shaft 13 to improve the rotational accuracy of the main shaft 13; specifically, the counterweight ring 32 is installed on the retaining ring 23 through a fastener.

[0068] Reference Figure 2 and Figure 3 In reference to [[ID=]], a through first through hole 2221 is provided on the outer magnetic guide seat 222. Through this first through hole 2221, it serves as a viewing window to facilitate the maintenance of the circular grating 31 and the reading head 61; on the side of the outer magnetic guide seat 222 away from the inner magnetic guide seat 221, there is an end cover 27a for blocking the first through hole 2221, and the end cover 27a is screwed or connected to the outer magnetic guide seat 222 through a fastener.

[0069] Embodiment 2

[0070] Reference Figures 5 to 7, the difference between this embodiment and the first embodiment is that in this embodiment, a centroid adjustment component 40 is provided on the table 12 or the main shaft 13 to meet the requirements of large loads of this angular vibration device. When the table 12 of this angular vibration device 10 is unloaded, the centroid of the moving parts is adjusted to the axis of the main shaft 13. On the one hand, this can make the moving parts have a smaller moment of inertia, and on the other hand, it can ensure that the table 12 is in the horizontal direction when it is stationary. When a test device with a large mass is placed on the table 12, the centroid of the entire moving parts will move upward, and even reach above the table 12. In this way, not only does the moment of inertia of the moving parts increase, but also the table will become unstable and fall to one side, thus increasing the control difficulty of the angular vibration device. For this reason, by setting the centroid adjustment component 40 under the table, the deviation of the centroid is compensated, and the overall centroid of the moving parts is adjusted to the axis of the main shaft 13, so that the moving parts can continue to maintain a smaller moment of inertia. In addition, the table 12 can be ensured to be in the horizontal direction when it is stationary, the control difficulty of the angular vibration device is reduced, and the distortion degree of the output motion waveform of the table 12 is further reduced.

[0071] Reference Figures 5 to 8 , the centroid adjustment component 40 includes a fixed balance block 41 detachably installed on the table 12 and a plurality of adjustable balance blocks 42 installed on the fixed balance block 41. The fixed balance block is set as a T-shaped structure, and the fixed balance block 41 is arranged at the reverse position of the centroid deviation of the moving parts, so as to adjust the uneven distribution of the overall centroid of the moving parts; in this embodiment, the fixed balance block is arranged on the side surface of the table close to the base, and the fixed balance block 41 has a flange surface 411 connected to the table 12. The adjustable balance block is set as a U-shaped block, and at least part of the structure of the fixed balance block 41 is clamped into the adjustable balance block 42, so that the adjustable balance block 42 can only slide along the length direction of the fixed balance block 41, and the fixed balance block 41 serves as a platform for the movement of the adjustable balance block 42; the adjustable balance block 42 and the fixed balance block 41 are fixed by a plurality of fastening bolts 43 and nuts 44.

[0072] By setting an adjustable balance block on the fixed balance block, when the moving parts are unloaded, the fixed balance block can adjust the centroid of the moving parts to the axis of the main shaft; however, when the table is loaded, the centroid will still shift. At this time, by adjusting the position of the adjustable balance block, the centroid deviation value is finely adjusted, so that the centroid of the moving parts returns to the axis of the main shaft again, further improving the adjustment accuracy of the uneven distribution of the centroid of the moving parts and having higher flexibility. The number and position of the adjustable balance blocks 42 can be adjusted according to the actual working conditions.

[0073] Reference Figure 8 and Figure 9, on one side of the fixed balance block 41, at least one guiding groove 412 is formed in a direction away from the tabletop, and the guiding groove 412 is a T-shaped groove; the large-diameter end of the fastening bolt 43 is located in the guiding groove 412, and the threaded section of the fastening bolt 43 passes through the adjustable balance block 42 and is connected to the nut 44. Tightening the nut 44 can fix the position of the adjustable balance block 42; by setting the guiding groove 412 as a T-shaped groove, when adjusting the position of the adjustable balance block 42, the large-diameter end of the fastening bolt 43 is always located in the T-shaped groove, facilitating the adjustment of the position of the adjustable balance block 42.

[0074] Reference Figure 8 and Figure 9 , a penetrating groove 413 communicating with the guiding groove 412 is further provided on the fixed balance block 41. The penetrating groove 413 is located at one end of the guiding groove 412 close to the flange surface 411, and the inner diameter of the penetrating groove 413 allows the large-diameter end of the fastening bolt 43 to penetrate, facilitating the assembly of the adjustable balance block 42. At least one transverse groove 421 through which the threaded section of the fastening bolt 43 can pass is further formed on the adjustable balance block 42. The transverse groove 421 is perpendicular to the guiding groove 412; in this embodiment, there are two guiding grooves 412, and the two guiding grooves 412 are arranged in parallel. Among them, there are also two transverse grooves 421, and the two transverse grooves 421 are also arranged in parallel, spanning the two guiding grooves 412, so that the four fastening bolts 43 located in the two guiding grooves 412 can respectively pass through the same transverse groove 421 in pairs, keeping the transverse groove 421 perpendicular to the guiding groove 412, thereby preventing the adjustable balance block 42 from shifting.

[0075] Reference Figures 5 to 7 , in this embodiment, there are two sets of centroid adjustment assemblies 40. The two sets of centroid adjustment assemblies 40 are arranged at intervals along the length direction of the main shaft 13 and are symmetrically arranged relative to the tabletop. The side plates 14 symmetrically arranged on the base 11 can protect the centroid adjustment assemblies 40. Of course, the number and specific installation positions of the centroid adjustment assemblies 40 can be set according to actual usage conditions.

[0076] Embodiment Three

[0077] Reference Figures 10 to 12, the difference between this embodiment and the first embodiment is that in this embodiment, a second driving component 50 associated with the table 12 and / or the spindle 13 partially penetrating the table is further provided on the base 11. The second driving component 50 is connected to the base 11 through a mounting seat 55, and the second driving component 50 is located between two groups of first driving components 20; the side plates 14 symmetrically arranged on the base 11 can protect the second driving component 5. The second driving component 50 includes a second moving coil assembly 51 mounted on the table 12 or the spindle and a second magnetic circuit assembly 52 cooperating with the second moving coil assembly 51; when the angular vibration device 10 works, when a test device with a large mass is installed on the table 12 and a gravitational moment acts on the table 12 and the spindle 13, when a current is passed through the second moving coil assembly, under the action of the air gap magnetic field generated by the second magnetic circuit assembly, a torque equal in magnitude and opposite in direction to the above-mentioned gravitational moment is generated on the second moving coil assembly for compensation.

[0078] Specifically, referring to Figure 12 and Figure 13 , the second magnetic circuit assembly 52 includes a first magnetic conductor 521, a second magnetic conductor 522, a first permanent magnet 523, a second permanent magnet 524, and a second air gap formed between the first permanent magnet 523 and the second permanent magnet 524.

[0079] The first magnetic conductor 521 and the second magnetic conductor 522 are respectively fixed on the mounting seat 55; a plurality of the first permanent magnets 523 are provided and are respectively fixed on the first magnetic conductor 521; a plurality of the second permanent magnets 524 are provided and are respectively fixed on the side wall of the second magnetic conductor 522 close to the first magnetic conductor 521; the first magnetic conductor 521, the second magnetic conductor 522, the first permanent magnet 523, the second permanent magnet 524, and the second air gap form a closed magnetic circuit system; the positions of the first permanent magnets 523 and the second permanent magnets 524 correspond one by one, and the second moving coil assembly 51 is in clearance fit with the first permanent magnets 523 and the second permanent magnets 524 respectively.

[0080] Referring to Figure 12 , Figure 13 and Figure 15 , the structures of the first permanent magnet 523 and the second permanent magnet 524 are the same. The first permanent magnet 523 and the second permanent magnet 524 respectively enclose a fan-shaped ring area, and the fan-shaped ring areas formed by a plurality of the first permanent magnets 523 and the fan-shaped ring areas formed by a plurality of the second permanent magnets 524 are coaxially arranged with the spindle 13. The first permanent magnet 523 and the second permanent magnet 524 are respectively arranged in a tile shape, and there is a gap between adjacent magnets in the circumferential direction.

[0081] Referring to Figure 13 and Figure 15, positioning members 56 are respectively arranged on the outer peripheries of the first magnetic steel 523 and the second magnetic steel 524. The positioning member 56 cooperating with the first magnetic steel 523 is connected to the first magnetic conductor 521 through a fastener, and the positioning member 56 cooperating with the second magnetic steel 524 is connected to the second magnetic conductor 522 through a fastener; the positioning member 56 is provided as a partial ring shape, and a clamping block 561 that can be inserted into the gap between adjacent magnetic steels is integrally formed on the positioning member 56, which is used to limit the first magnetic steel 523 or the second magnetic steel 524 to prevent displacement and ensure the stability of the air-gap magnetic field.

[0082] Reference Figures 12 to 14 , the second moving coil assembly 51 is provided as a semi-disc structure. The second moving coil assembly 51 includes at least one second moving coil unit, and the second moving coil unit includes a semi-circular sheet-shaped second base body 511 and at least one second coil group fixed on the surface of the second base body 511; in this embodiment, there is one second coil group on one second base body, and the second coil group includes a first coil 512a and a second coil 512b wound by a single wire.

[0083] Reference Figure 14 , the first coil 512a is wound by a wire gradually from small to large from the inside to the outside, and the second coil 512b is wound by a wire gradually from large to small from the outside to the inside. All the wires are on the surface of the second base body 511. The second coil group starts from the starting end 516 on the inner side of the first coil 512a and ends at the ending end 517 on the inner side of the second coil 512b.

[0084] The first coil 512a includes an effective wire group 513a located in the air-gap magnetic field and a first connecting wire group 514a and a second connecting wire group 515a located outside the air-gap magnetic field. The first coil 512a has two effective wire groups 513a, and the wires in the effective wire group 513a all point to the center of the second base body 511.

[0085] The first connecting wire group 514a, the second connecting wire group 515a and the second base body 511 are concentrically arranged. The first connecting wire group 514a and the second connecting wire group 515a are respectively located between the two effective wire groups 513a, and the first connecting wire group 514a is relatively close to the center of the second base body, and the second connecting wire group 515a is relatively far from the center of the second base body.

[0086] The second coil 512b has the same structure as the first coil 512a, including an effective wire group 513b located in the air-gap magnetic field and a first connecting wire group 514b and a second connecting wire group 515b located outside the air-gap magnetic field.

[0087] The second coil 512b has two effective wire groups 513b, and the wires in the effective wire group 513b all point to the center of the second base body 511.

[0088] The first connecting wire group 514b, the second connecting wire group 515b and the second base body 511 are concentrically arranged. The first connecting wire group 514b and the second connecting wire group 515b are respectively located between two effective wire groups 513b, and the first connecting wire group 514b is relatively close to the center of the second base body, while the second connecting wire group 515b is relatively far from the center of the second base body.

[0089] With such a solution, by arranging coils on the semi - disc - shaped second base body, the volume of the moving coil becomes smaller, the weight becomes lighter, the stiffness becomes larger, the rotational inertia of the moving coil is reduced, and the natural frequency of the moving coil is increased.

[0090] Figure 14 The positional relationship between the first coil 512a and the second coil 512b and the first permanent magnet 523 is shown.

[0091] Reference Figure 10 , two effective wire groups in each coil respectively correspond to different first permanent magnets 523, and the magnetic field directions in the second air gaps corresponding to two adjacent first permanent magnets 523 in the circumferential direction are opposite. When current is passed through the coil, since the current directions of the two effective wire groups in one coil are opposite, the Ampere force directions received by these two effective wire groups are the same, and then torques in the same direction are generated.

[0092] An effective wire group 513a of the first coil 512a and an effective wire group 513b of the second coil 512b adjacent to it form an Ampere - force generating part 518, making the structure of the coil group more compact; the air - gap magnetic field directions received by the Ampere - force generating part 518 are the same, and the current directions of the effective wire group 513a and the effective wire group 513b in the Ampere - force generating part 518 are the same, so that the Ampere - force generating part 518 receives an Ampere force in a single direction, and then generates a torque in the same direction.

[0093] Certainly, in other embodiments, a second base body 511 has multiple second coil groups, and the second coil groups are connected in series or in parallel.

[0094] When the number of second moving - coil units is multiple, the multiple second moving - coil units are connected in series or in parallel.

[0095] Series connection means that in two adjacent second moving - coil units, the starting point of the coil of one second moving - coil unit is connected to the ending point of the coil of the other second moving - coil unit.

[0096] Parallel connection means that for two adjacent second moving - coil units, the starting point of the coil of one second moving - coil unit is connected to the starting point of the coil of the other second moving - coil unit, and the ending point of the coil of one second moving - coil unit is connected to the ending point of the coil of the other second moving - coil unit.

[0097] The method for manufacturing the above-mentioned second moving coil assembly 51 refers to Chinese Patent CN 201310451020.6.

[0098] Refer to Figure 12 and Figure 13 , a notch 122 is formed on one side of the tabletop 12 facing the base 11, so that a part of the position of the main shaft 13 corresponding to the notch 122 is exposed; a part of the second moving coil assembly 51 is located in the notch 122, and a groove capable of covering a part of the circumferential surface of the main shaft 13 is provided on the second moving coil assembly 51, and the inner wall of the groove is attached to the side wall of the main shaft 13, so that the second moving coil assembly 51 can generate a torque relative to the axis of the main shaft 13.

[0099] Refer to Figure 12 and Figure 16 , the second base body 511 and the tabletop 12 are fixedly connected through a connection structure, and the connection structure includes a first fixing block 53 and a second fixing block 54; two first fixing blocks 53 are provided, symmetrically arranged on both sides of the second base body 511 to limit the position of the second base body 511, and the first fixing block 53 is in a tile shape, and an arc surface 531 covering the main shaft 13 is provided on the side facing the tabletop 12 to position the first fixing block 53 so that the center line of the first fixing block 53 coincides with the axis of the main shaft 13; one end of the first fixing block 53 abuts against the second base body 511, and the first fixing block 53 has a first connecting portion 532 for connecting with the second base body 511 and a second connecting portion 533 for connecting with the tabletop 12; the first connecting portion 532 is in a partial ring shape, located at one end of the first fixing block 53 facing the second base body 511, and the first connecting portion 532 and the second base body 511 are connected through fasteners; the second connecting portion 533 is formed by the axis of the arc surface 531 extending radially, two are provided, and are symmetrically arranged relative to the first connecting portion 532, and the second connecting portion 533 and the tabletop 12 are connected through fasteners.

[0100] Refer to Figure 16 , 4 second fixing blocks 54 are provided, and every two second fixing blocks 54 are set as a group, and the two groups are respectively located at positions far from the center line of the second base body 511, and the two second fixing blocks 54 in one group are symmetrically arranged with respect to the second base body 511; the second fixing block 54 is in an L shape and has a first branch 541 connected to the second base body 511 and a second branch 542 connected to the tabletop 12, further improving the stability of the second base body 511.

[0101] In this embodiment, refer to Figure 12, two sets of the second driving components 50 are provided, and the two sets of second driving components 50 share a magnetic conductor 521. The cross-section of the first magnetic conductor 521 is set as an inverted T shape, and the second magnetic conductors 522 of the two sets of second driving components 50 are symmetrically arranged on both sides of the first magnetic conductor 521, with a compact structure and reduced production costs. Of course, the number of the second driving components 50 is not limited to the example in this embodiment, and each set of second driving components 50 can be independently arranged at intervals.

[0102] In this embodiment, the specific working principle of the second driving component 50 for torque compensation is as follows:

[0103] S1: When no test equipment is placed on the tabletop, when the tabletop of the horizontal axial angular vibration device 10 is horizontal, it is recorded as the equilibrium position, and the circular grating records the zero position.

[0104] S2: When the test equipment is placed on the tabletop, the center of mass of the moving part moves upward, resulting in the overall center of mass of the moving part deviating from the axis of the main shaft to above it, generating a deflecting moment relative to the axis, so that the overall moving part becomes unstable and deviates from the zero position.

[0105] S3: The circular grating feeds back the overall angular displacement signal of the moving part to the host computer.

[0106] S4: The host computer calculates the magnitude of the deflecting moment according to the overall angular displacement of the moving part, outputs a corresponding current to the second moving coil assembly 51, and the second driving component 50 generates a compensation moment equal in magnitude and opposite in direction to the deflecting moment to compensate the position of the moving part, so that the tabletop returns to horizontal and returns to the zero position.

[0107] Embodiment 4

[0108] Reference Figure 17 And Figure 19 , the difference between this embodiment and Embodiment 3 is that: in this embodiment, the first driving component 20 is not provided, and at least one set of second driving components 50 associated with the main shaft 13 and / or the tabletop 12 is only provided on the base 11. The second driving component 50 directly drives the main shaft 13 to rotate back and forth, so that there will be an angular motion output on the tabletop 12 to excite the test equipment. In this embodiment, the maximum angular displacement of the second moving coil assembly 51 is determined by the maximum angle that the effective wire group 513 can rotate in the same air gap magnetic field, and the maximum angular displacement of the second moving coil assembly 51 determines the maximum output amplitude of the tabletop. According to the requirements of the output angular amplitude of different angular vibration devices 10 and the design concept of fully utilizing the matrix space to arrange the coils, a moving coil structure with different numbers of coil groups can be designed.

[0109] Reference Figures 17 to 19, two first supports 111 are symmetrically arranged on the base 11, and both ends of the main shaft 13 are supported on the first supports 111 through radial air bearings 26 respectively. A second support 112 is further arranged on the side of the first support 111 away from the tabletop, and the second support 112 is also fixed on the base 11. A through second through hole 1121 is provided on the second support 112, and a part of the end of the main shaft 13 extends into the second through hole 1121; an end cover 27b for blocking the second through hole 1121 is arranged on the side of the second support 112 away from the first support 111, and the end cover 27b is screwed or connected to the second support 112 through fasteners.

[0110] In this embodiment, referring to Figure 19 , there are two groups of the second driving components 50, and the two groups of the second driving components 50 share a magnetic conductor 521. The cross-section of the first magnetic conductor 521 is set as an inverted T shape, and the second magnetic conductors 522 of the two groups of the second driving components 50 are symmetrically arranged on both sides of the first magnetic conductor 521, with a compact structure and reduced production costs; of course, the number of the second driving components 50 is not limited to the example in this embodiment, and each group of the second driving components 50 can be independently arranged at intervals.

[0111] Furthermore, the angular vibration device 10 is provided with at least two groups of second driving components, and at least one group of the second driving components is passed through an alternating current to drive the main shaft or the tabletop to perform angular vibration, and the remaining second driving components are used as torque compensation; when the angular vibration device 10 works, when a test device is installed on the tabletop 12, the center of mass of the moving part moves upward, and the overall center of mass of the moving part deviates from the axis of the main shaft to above it, generating a gravitational moment acting on the tabletop 12 and the main shaft 13. The second driving component 50 used as torque compensation can generate a torque with the same magnitude and opposite direction for compensation. All the second driving components 50 can be combined in a way of being separately arranged or sharing the first magnetic conductor 521.

[0112] The working principle of the second driving component in this embodiment is as follows:

[0113] St1: When no test device is placed on the tabletop, according to the design requirements, the center of mass of the moving part is just located on the axis of the main shaft; at this time, the tabletop can be made to stay in a horizontal position, which is set as the balance position of the moving part and the zero position recorded by the circular grating;

[0114] St2: When the test device is placed on the tabletop, the center of mass of the moving part will shift upward. When the center of mass of the moving part is above the axis of the main shaft, the gravity of the moving part will generate a deflecting gravitational moment, causing the overall rotation of the moving part to deviate from the zero position;

[0115] St3: The second driving component as the power source drives the moving part to swing back and forth around the balance position, and the circular grating feeds back the overall angular displacement signal of the moving part to the host computer;

[0116] St4: The host computer calculates the magnitude of the deflection gravitational torque based on the overall deflection angular displacement of the moving part, and outputs a corresponding current to the second moving coil assembly in the second driving part used for torque compensation. The second driving part used for torque compensation generates a compensation torque with the same magnitude and opposite direction as the deflection gravitational torque to compensate the position of the moving part, so that the tabletop is horizontal and returns to the zero position.

[0117] The above-described embodiments do not constitute a limitation on the protection scope of the technical solution. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the above embodiments are included in the protection scope of the technical solution.

Claims

1. A device for stably outputting horizontal axial angular vibration, characterized in that: It includes a base; a moving part, including a table for placing the device under test and a main shaft connected to the table to drive the table to deflect back and forth, and the axis of the main shaft is horizontally arranged; a first driving part, including a first moving coil assembly installed on the moving part and associated with the main shaft, and a first magnetic circuit assembly installed on the base and cooperating with the first moving coil assembly; when an alternating current is applied to the first moving coil assembly, in the air-gap magnetic field generated by the first magnetic circuit assembly, an alternating driving torque is generated on the first moving coil assembly, thereby driving the moving part to swing back and forth around the equilibrium position to realize the angular vibration of the table; a centroid adjustment component, associated with the table and / or the main shaft to adjust the overall centroid of the moving part to the axis of the main shaft.

2. The device for stably outputting horizontal axial angular vibration according to claim 1, characterized in that: There are at least two groups of the centroid adjustment components, and the two groups of centroid adjustment components are arranged at intervals along the length direction of the main shaft and are symmetrically arranged relative to the table.

3. The device for stably outputting horizontal axial angular vibration according to claim 1, characterized in that: The centroid adjustment component includes a fixed balance block arranged on the table, and the fixed balance block is arranged at the reverse position where the centroid of the moving part deviates.

4. The device for stably outputting horizontal axial angular vibration according to claim 3, characterized in that: The centroid adjustment component further includes an adjustable balance block movably arranged on the fixed balance block.

5. The device for stably outputting horizontal axial angular vibration according to claim 4, characterized in that: The adjustable balance block and the fixed balance block are fixed by a plurality of fastening bolts and nuts. A guide groove is formed on one side surface of the fixed balance block in a direction away from the table, and the guide groove is a T-shaped groove. The large-diameter end of the nut can slide in the T-shaped groove, and the threaded section of the fastening bolt passes through the adjustable balance block and is connected to the nut.

6. The device for stably outputting horizontal axial angular vibration according to claim 1, characterized in that: There are two groups of the first driving parts, and the two groups of first driving parts are symmetrically arranged at both ends of the main shaft to drive the main shaft to rotate simultaneously; the first moving coil assembly includes a first base body and at least one first coil group fixed on the surface of the first base body, and the first base body is fixedly connected to the main shaft.

7. The device for stably outputting horizontal axial angular vibration according to claim 6, characterized in that: The first magnetic circuit assembly includes an inner magnetic guide seat arranged on the base, an outer magnetic guide seat arranged on the base and corresponding to the inner magnetic guide seat, an inner side magnetic steel arranged on the inner magnetic guide seat, an outer side magnetic steel arranged on the outer magnetic guide seat, and a first air gap formed between the inner side magnetic steel and the outer side magnetic steel; the first moving coil assembly is in clearance fit with the inner side magnetic steel and the outer side magnetic steel respectively.

8. The device for stably outputting horizontal axial angular vibration according to claim 7, characterized in that: The inner magnetic steel and the outer magnetic steel have the same structure. The inner magnetic steel and the outer magnetic steel respectively enclose a circular ring region. The circular ring region enclosed by the inner magnetic steel and the circular ring region enclosed by the outer magnetic steel are coaxially arranged, and the main shaft extends into the circular ring region. The number of the outer magnetic steel and the inner magnetic steel is equal, and the positions of the inner magnetic steel and the outer magnetic steel correspond one by one. The number of the outer magnetic steel and the inner magnetic steel is a multiple of 2.

9. A stable output horizontal axial angular vibration device according to claim 7, characterized in that: Positioning rings are respectively arranged on the outer peripheries of the inner magnetic steel and the outer magnetic steel, and the inner wall of the positioning ring is in contact with the outer shapes of the inner magnetic steel and the outer magnetic steel; positioning grooves matched with the positioning rings are respectively arranged on the inner magnetic guide seat and the outer magnetic guide seat, and part of the positioning ring is clamped into the positioning groove.

10. A stable output horizontal axial angular vibration device according to claim 7, characterized in that: The stable output horizontal axial angular vibration device further includes a radial air bearing and an axial air bearing. The main shaft is connected to the inner magnetic guide seat through the radial air bearing. The radial air bearing includes an air floating sleeve sleeved on the main shaft and a bearing seat matched with the air floating sleeve. A radial air film is formed between the air floating sleeve and the side wall of the main shaft. The bearing seat is installed on the inner magnetic guide seat. Axial air bearings are respectively arranged at both ends of the main shaft. The axial air bearing includes a plane air floating bearing thrusting against the end of the main shaft, a pressing bolt and a supporting plate matched with the plane air floating bearing. An axial air film is formed between the plane air floating bearing and the end of the main shaft. The supporting plate is installed on the outer magnetic guide seat.

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