CN116665526A - Magnetic suspension demonstration system for displaying horizontal rotating shaft state - Google Patents

Abstract

The invention relates to a magnetic suspension demonstration system for displaying a horizontal rotating shaft state, which structurally comprises a stator and a floater; the stator comprises a bottom plate, a left bracket and a right bracket which are arranged on the bottom plate, a floater traction coil which is arranged on the left bracket, a positioning coil group and a position sensor which are arranged on the right bracket, a rotary driving coil group which is arranged in the middle of the bottom plate, and a left end lifting magnet and a right end lifting magnet which are arranged on the bottom plate; the float comprises a horizontal shaft rod, a rotary magnet group which is connected to the middle of the shaft rod in a penetrating way, and a left end suspension magnet and a right end suspension magnet which are arranged at the end part of the shaft rod. The magnetic suspension demonstration system can display the floater into the state of the horizontal rotating shaft, the floater can stably suspend and can rotate in a controlled way, the start-stop function of the floater is ensured by the self suspension structure and the electric link, a mechanical motion supporting structure is not provided, and the failure rate of automatic suspension operation and demonstration can be greatly reduced.

Description

Magnetic suspension demonstration system for displaying horizontal rotating shaft state

Technical Field

The invention relates to a physical teaching tool, in particular to a magnetic suspension demonstration system for displaying a horizontal rotating shaft state.

Background

The magnetic suspension system uses magnetic force to make the object in a suspension state without mechanical contact, and related products are widely applied. At present, the float structure in the vertical axial direction is used in many fields of teaching, science popularization, ornamental and the like. In addition, some horizontal magnetic suspension products in horizontal axial direction need to be mechanically supported in one axial dimension, but the mechanical support is not a complete magnetic suspension mechanism, so that the magnetic suspension concept is not helpful to be correctly understood and mastered. In addition, most products require manual float placement during the start-up phase, but require some experience or exercise to find out the magnetic field laws. This presents certain operational difficulties for the primary user.

CN204261350U discloses a toy and popular device with a float which can rotate horizontally and axially and has a better ornamental effect than a stationary magnetic levitation, on the basis of reference to the structure of a door motor, which structure requires that one end of the suspension be mechanically supported on a pallet of the levitation device to limit the freedom of its axial movement. This float, which can only produce a "half-levitation" effect, does not allow a complete six-degree-of-freedom magnetic levitation state if strictly defined as above. While CN2569440Y discloses a method of electromagnetically providing its horizontal axial suspension support in an attempt to solve the aforementioned problem of incomplete magnetic suspension of the float. However, in the device used in this method, the axial direction of the magnetic coil does not coincide with the axial direction of the float, and the effect of the electromagnetic action provided is only enhanced or reduced in the direction of the magnetic field originally inherent to the permanent magnet. Embodying the controlled end of the horizontal float, it is more likely that radial displacement is affected than axial displacement, and thus it is difficult to provide stable suspension control. CN111726038A discloses an automatic centering and position lifting method for a floater, but the mechanical movement mechanism is complex, and faults are unavoidable during long-term operation demonstration.

Disclosure of Invention

The invention aims to provide a magnetic suspension demonstration system for displaying a horizontal rotating shaft state, so as to solve the problem that the existing magnetic suspension demonstration device needs to manually realize initial setting and suspension of a floater and realize controlled rotation of the floater.

The invention is realized in the following way:

a magnetic suspension demonstration system for displaying a horizontal rotating shaft state comprises a stator and a floater;

the stator comprises a bottom plate, a left bracket and a right bracket which are arranged on the bottom plate, a floater traction coil which is arranged on the left bracket, a positioning coil group and a position sensor which are arranged on the right bracket, a rotary driving coil group which is arranged in the middle of the bottom plate, and a left end lifting magnet and a right end lifting magnet which are arranged on the bottom plate;

the floater comprises a horizontally arranged shaft rod, a rotary magnet group which is connected to the middle of the shaft rod in a penetrating way, and a left end suspension magnet and a right end suspension magnet which are arranged at the end part of the shaft rod;

the left end suspension magnet is vertically opposite to the left end lifting magnet, and the right end suspension magnet is vertically opposite to the right end lifting magnet and is used for generating magnetic repulsive force for lifting the floater; the magnets in the rotary magnet group are in one-to-one correspondence with the coils in the rotary driving coil group and are opposite up and down, so as to generate driving force for rotating the floater.

Further, the left end lifting magnet and the right end lifting magnet are formed by arranging two cylindrical magnets side by side at intervals; the two cylindrical magnets are axially magnetized, and the magnetization directions are consistent, so that stable and uniform lifting magnetic fields are formed in the middle parts of the two cylindrical magnets.

Further, the left end suspension magnet is a cylindrical magnet, is axially magnetized, and has the same magnetizing direction as that of a magnet pair in the left end lifting magnet; the right end suspension magnet is a cylindrical magnet, is axially magnetized, and has the same magnetizing direction as that of the magnet pair in the right end lifting magnet.

Further, the positioning coil group comprises four coils with the same physical structure and electrical parameters, the four coils are distributed on the upper, lower, left and right directions of the position sensor, the four coils are divided into an upper group, a lower group and a left group, two coils in each group are connected in series or in parallel, and the direction of the energizing current is opposite.

Further, the distance between the position sensor and the four coils in the positioning coil group is the same, and the height of the position sensor protruding out of the surface of the bracket is half of the height of the coils.

Further, the rotary magnet group comprises at least three annular permanent magnets, wherein the permanent magnets are radially magnetized and are fixedly connected to the shaft rod in a penetrating way in an equidistant mode; the magnetic field directions of the permanent magnets are distributed at equal angles on the radial circumference of the shaft rod, namely, the permanent magnets are equally distributed with the angles of the circumferential angles of the floats in the respective magnetic pole direction sequence.

Further, the rotary driving coil group comprises coils with the same number as the permanent magnets in the rotary magnet group, all the coils are arranged on the bottom plate in a straight line along the length direction, and one coil is opposite to one permanent magnet in the vertical position.

Further, the arrangement interval between the left end suspension magnet and the right end suspension magnet is not equal to the arrangement interval between the left end lifting magnet and the right end lifting magnet.

Further, the coils in the rotary drive coil group are linearly arranged along the axial direction of the float.

Further, the permanent magnets in the rotary magnet group are mounted in a spiral manner in accordance with the magnetic pole directions thereof.

The invention is electrically composed of two mutually independent basic structures, namely a suspension mechanism and a rotation mechanism. The suspension mechanism uses two lifting type magnetic suspension nodes which are separated by a certain distance and mutually independent, and jointly supports a float which is horizontally and axially arranged and has a suspension function, and two ends of the float are respectively provided with a cylindrical suspension magnet which is axially magnetized, and the cylindrical suspension magnets are respectively lifted by the lifting magnets at two ends of the stator to realize stable suspension. The floater can freely rotate around the shaft lever, thereby forming a controllable suspension and rotation science and education demonstration device combining the magnetic suspension technology with the stepping and synchronous motor control technology, and the device can also be used as a desktop ornamental ornament.

The invention relates to a magnetic suspension demonstration mechanism with floats capable of exhibiting a horizontal rotation state, wherein the floats in the system not only can stably suspend, but also can rotate in a controlled manner; particularly, the starting and stopping functions of the floats are ensured by the self suspension structure and the electrical links, no mechanical motion supporting structure is needed, the initial setting and the manual operation of initial suspension of the floats are not needed, and the failure rate of automatic suspension operation and demonstration can be greatly reduced.

Drawings

Fig. 1 is a schematic structural diagram of a magnetic levitation demonstration system of the present invention.

Fig. 2 is a schematic view of the installation position of the float traction coil.

Fig. 3 is a schematic diagram of an arrangement of a positioning coil set and a position sensor.

Fig. 4 is a diagram of the left end of the magnet levitation relationship.

Fig. 5 is a diagram of the right-hand magnet levitation relationship.

Fig. 6 is a radial force analysis chart of the left magnet in the magnetic levitation demonstration system of the present invention.

Fig. 7 is an axial force analysis diagram of the right magnet in the magnetic levitation demonstration system of the present invention.

Fig. 8 is a diagram of the magnetic field lines between the coils of the same set in the positioning coil set.

Fig. 9 is a schematic view of the pole arrangement of each permanent magnet in the rotating magnet group.

Fig. 10 is a schematic structural view of the magnetic levitation demonstration system of the present invention after the float and the sleeve.

Fig. 11 is a block diagram of the system controller.

In the figure: 1. the device comprises a bottom plate, 2, a float traction coil, 3, a left end suspension magnet, 4, a shaft rod, 5, a rotary magnet group, 6, a right end suspension magnet, 7, a positioning coil group, 8, a float support pad, 9, a right end support magnet, 10, a rotary driving coil group, 11, a left end support magnet, 12, a position sensor, 13, a left support, 14 and a right support.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings.

As shown in fig. 1, 2 and 3, a stator in the magnetic levitation demonstration system of the present invention is provided with a left bracket 13 at one end of a rectangular flat plate-shaped bottom plate 1, a right bracket 14 at the other end of the bottom plate 1, and the left bracket 13 is opposite to the plate surface of the right bracket 14. A float traction coil 2 is arranged on the outer side surface of the left bracket 13 in the middle; the float support pad 8 is arranged in the middle of the inner side surface of the right support 14, the position sensor 12 is arranged in the middle of the outer side surface of the right support 14, a coil is further arranged on the upper, lower, left and right directions of the position sensor 12, and the four coils form the positioning coil group 7 for the floats. A rotary drive coil assembly 10 consisting of four coils arranged in a straight line is also provided in the middle of the base plate 1, and the four coils are arranged linearly in the axial direction of the float. The bottom plate 1 inside the left bracket 13 is also provided with a left end lifting magnet 11, and the bottom plate 1 inside the right bracket 14 is provided with a right end lifting magnet 9. The left end lifting magnet 11 and the right end lifting magnet 9 are formed by arranging two cylindrical magnets side by side at intervals; the two cylindrical magnets in each lifting magnet are axially magnetized, and the magnetization directions are consistent, so that a stable and uniform lifting magnetic field is formed in the middle of the two magnets.

As shown in fig. 1 and 9, the float in the magnetic suspension demonstration system of the invention comprises a horizontal shaft lever 4 and a rotary magnet group 5 penetrating through the middle of the shaft lever; the rotary magnet set 5 comprises four annular permanent magnets which are radially magnetized and are fixedly connected to the shaft lever 4 in a penetrating manner at equal intervals. The magnetic field directions of the permanent magnets are distributed at equal angles on the radial circumference of the shaft rod, namely, the permanent magnets are equally distributed with the angles of the circumferential angles of the floats in the respective magnetic pole direction sequence. In the present embodiment, four permanent magnets are sequentially arranged at intervals in the middle of the shaft lever 4 in such a manner that the magnetic pole order differs by 45 ° (the circumferential angle of the magnetic pole is 180 °, and the four permanent magnets are equally divided, that is, 180 ° -4=45°). The four permanent magnets are positioned to face four coils in the rotary drive coil assembly 10 on the stator one by one up and down and are mounted in a spiral manner in accordance with the magnetic pole directions thereof. The left end suspension magnet 3 is connected and fixed to the left end of the shaft lever 4, and the right end suspension magnet 6 is connected and fixed to the right end of the shaft lever 4. The left end suspension magnet 3 is vertically opposite to the left end lifting magnet 11 on the stator, and the right end suspension magnet 6 is vertically opposite to the right end lifting magnet 9 on the stator.

The left end suspension magnet 3 in the floater is a cylindrical magnet, is magnetized in the axial direction, and has the same magnetizing direction as the two cylindrical magnets in the left end lifting magnet 11 (fig. 4); the right end suspension magnet 6 is also a cylindrical magnet, is magnetized in the axial direction, and has the same magnetizing direction as the two cylindrical magnets in the right end lifting magnet 9 (fig. 5), so that the magnetic repulsive force for lifting the floater can be generated, and the magnetic field relationship formed between the suspension magnet on the floater and the lifting magnet on the stator can be independent of the rotation of the floater.

The lifting of the stator to the floater in the magnetic suspension demonstration system is realized by the lifting mechanisms at two ends. The lifting mechanism comprises a right lifting magnet 9 and a left lifting magnet 11 on the stator, and further comprises a left suspension magnet 3 and a right suspension magnet 6 on the floater. Two cylindrical magnets in each lifting magnet (9, 11) on the stator are axially magnetized, uniformly magnetized and consistent in magnetization direction, and are arranged on the bottom plate 1 side by side at a certain distance. Lifting magnets (9, 11) at both ends of the stator correspond to the levitation magnets (3, 6) at both ends of the float, so that the float is supported and a stable equilibrium state can be achieved under the control of the system controller.

The following is a brief analysis description of the lifting mechanics relationship of the magnetic levitation demonstration system of the present invention.

As shown in fig. 1, when the float is located directly above the stator, the left end levitation magnet 3 and the right end levitation magnet 6 each correspond up and down to the lifting magnet on the lower stator. The left end suspension magnet 3 and the left end lifting magnet 11 are positioned on the same vertical plane in the same magnetic field direction, so that all the left end suspension magnet and the left end lifting magnet are subjected to repulsive force (see fig. 4 and 5). Since the two cylindrical magnets of the left-end lifting magnet 11 are fixed to the base plate 1, the movable part has only the left-end levitation magnet 3. As shown in fig. 6, the left end levitation magnet 3 has a gravity G and receives the supporting forces from two directions of two single magnets in the left end lifting magnet 11. At this time, the gravity G of the float can be decomposed into component forces G directed to the left and right single magnets in the left-end lifting magnet 11 _L And G _R . While the lifting force of the two single magnets pointing to the left end suspension magnet 3 is respectively N _L And N _R . Gravity component force vector G in the figure _L 、G _R And can be decomposed into F _L 、F _LV And F _R 、F _RV Corresponding supporting force component force vector N _L 、N _R Then decompose into N _LV 、N _LH And N _RV 、N _RH . It can be seen that the presence of gravity G also ensures that a radially offset component F can be generated to the float in the free-floating state _LV And F _RV Is a radial stabilizing force (N) _LH And N _RH ). Therefore, while the weight of the float in the vertical direction is thus balanced, its radial translation is necessarily balanced, since the left end levitation magnet 3 and the right end levitation magnet 6 are also each in their radial motion-limited stator magnetic field structure.

As shown in fig. 2, 3, 4 and 5, axial position regulating mechanisms are provided at both ends of the stator, respectively, and include a float traction coil 2 mounted on a left bracket 13, and a positioning coil group 7 and a position sensor 12 mounted on a right bracket 14. The position sensor 12 is used for three-dimensionally and precisely positioning the right end suspension magnet 6, and any offset of the right end of the float is transmitted to a suspension control unit of the system controller in real time. The positioning coil group 7 is used for precisely adjusting the vertical and radial positions of the right end suspension magnet 6 on the shaft lever 4; while the left-hand float traction coil 2 is used to provide axial traction to the entire float, the entire axial position of which is adjusted by the left-hand suspension magnet 3 fixed to the left-hand end of the shaft 4.

As shown in fig. 11, the system controller includes a levitation control unit, a levitation driving circuit, a rotation control unit, and a rotation driving circuit. The suspension control unit receives detection data sent by the position sensor 12 in real time, judges the current axial deviation of the floater according to the right-end suspension magnet 6 on the floater, and drives the floater traction coil 2 through the suspension driving circuit according to the current axial deviation, so as to adjust the axial position of the left-end suspension magnet 3 on the floater. The single-end positioning and opposite-side control mode has the advantages that mutual interference between magnetic fields during axial position detection and positioning adjustment of a general magnetic suspension system is avoided, so that the influence of a magnetic field at a control end in the magnetic suspension system on the magnetic field at a positioning end is reduced to the minimum, and the overall stability is greatly improved.

When the traditional magnetic suspension device is stopped, the floats can naturally fall off. When the power-on resumes the working state, the float is also placed in a proper working position. Therefore, certain modes and techniques are also required. In order to enable the float to automatically return to a fully suspended working state when the float is electrified, the float needs to have a fixed stop position after each power-off. When the whole system stops working, the system structure can ensure that the floater naturally deflects towards the right end of the floater, so that the right end of the floater directly abuts against the floater supporting pad 8 on the inner side surface of the right bracket 14 to form an axial mechanical supporting point, and the whole floater is balanced at a new position and is in a semi-suspension state which provides support at the right end in the axial direction through a mechanical mode. The specific mechanical relationships can be analytically described as follows.

The arrangement distance between the left end suspension magnet 3 and the right end suspension magnet 6 in the floater can be larger or smaller than the arrangement distance between the left end lifting magnet 11 and the right end lifting magnet 9 on the stator. The present embodiment will be described by taking "greater than" as an example. In normal operation, the left end levitation magnet 3 is aligned up and down with the left end lifting magnet 11 to obtain maximum lifting force (fig. 4). While the right end levitation magnet 3 is not aligned with the right end lifting magnet 9 but protrudes slightly to the right (fig. 5). This way the lifting force obtained on the right side of the float does not coincide exactly with its weight, but is slightly inclined to the right. As shown in fig. 7, the right end levitation magnet 6 is positioned along its center position C ₁ And center C of right end lift magnet pair 9 ₂ The right end lifting magnet pair 9 is lifted by the lifting force F. The force can be decomposed into a vertically upward lifting force F _V And also decompose an axial component force F to the right _H . When the magnetic suspension demonstration system works normally, the float traction coil 2 provides the axial component force F _H The axial stress of the floats is zero and the floats are in a stable balance state due to the attractive forces with equal magnitude and opposite directions. When the system stops working, the attractive force provided by the float traction coil 2 disappears, and the right-hand component force F exerted by the right-hand levitation magnet 6 _H Still exists. This force component pulls the float to the right, causing its right end to bear directly against the float cushion 8 on the inside of the right bracket 14. This arrangement ensures that the float does not move left by itself. The stopping distance of the floater can be conveniently adjusted by adjusting the thickness of the floater supporting pad 8.

When the magnetic levitation demonstration system is powered on, the electromagnetic attraction of the float traction coil 2 will pull the float back to the levitated equilibrium position. The system then automatically returns to the operating state without any manual or other mechanical means for resetting. At this time, the left end levitation magnet 3 is aligned with the left end lifting magnet 11, the axial component force of the left end levitation magnet 3 itself is 0, and the float always needs to be attracted by the float traction coil 2 to balance the right component force applied to the right end levitation magnet 6. Therefore, once one end of the left end levitation magnet 3 is offset in the radial or vertical direction, the attractive force of the float traction coil 2 automatically directs the left end levitation magnet 3 to the center of the float traction coil 2, thereby also ensuring the stability of the left end of the float.

Since the position sensor 12 is provided at the right end of the magnetic levitation presentation system, the steady state of the right-end levitation magnet 6 plays a vital role in the stabilization of the entire magnetic levitation presentation system. Therefore, a set of positioning coils, i.e. a set of positioning coils 7, is provided on the right side of the stator in order to give accurate adjustment of the right end levitation magnet 6 both radially and vertically in combination with the three-dimensional data of the position sensor 12, ensuring that the right end of the float is as stable as possible.

As shown in fig. 3, the positioning coil set 7 includes four coils with identical physical structure and electrical parameters, and the four coils are fixed on the upper, lower, left and right directions of the position sensor about the position sensor 12. The four coils are divided into an upper group of vertical positioning coils and a lower group of radial positioning coils. The two coils in each group are connected in series or parallel, but the current direction of the current is kept opposite, so that the magnetic poles generated by the two coils in each group are opposite, thereby forming closed magnetic lines (i.e. the broken line in fig. 8).

It can be seen that the effect of the adjusting magnetic field generated by the coil on the position sensor 12 is zero if and only if the position sensor 12 is fixed in the middle of two coils of the same direction and its height is half the height of the coil. That is, the position sensor 12 can thus avoid disturbances in the adjustment of the magnetic field, whether in the radial or vertical direction. In the magnetic levitation demonstration system of the present invention, the axial adjustment of the float is accomplished by the float traction coil 2 on the left side of the system, which is a relatively large distance from the position sensor 12, and the resulting traction magnetic field has negligible effect on the position sensor.

It follows that the positioning and stabilizing of the two ends of the float are different, the vertical and radial positioning of the right end of the float is performed by the vertical positioning coil and the radial positioning coil in the local positioning coil set 7, respectively, and the vertical and radial positioning of the left end of the float and the axial positioning of the whole float are performed by the float traction coil 2. Therefore, the double-end lifting, single-end positioning and opposite-side shaft control technology used by the magnetic suspension demonstration system can ensure the stability of the suspended state of the floater in a very simple and very reliable mode.

In the magnetic suspension demonstration system, the implementation of the float rotation mode adopts a structure that the linear arrangement of the rotation driving coils is matched with the spiral installation of the float permanent magnet. As shown in fig. 9, four ring-shaped permanent magnets in the rotary magnet group 5 provided in the middle of the float each have a pair of poles magnetized in the radial direction, and are fixed to the shaft lever 4 sequentially at equal intervals in such a manner that the order of the poles differs by 45 °. Four coils arranged linearly at equal intervals are mounted on the base plate 1 to constitute a rotation control coil group 10. The four coils are in one-to-one correspondence with the four annular permanent magnets on the floats. The entire float can be stably rotated around the shaft in a stepwise manner or a continuous manner by applying a regular pulse or a sinusoidal drive to the four coils in the rotary drive coil assembly 10 in an open loop control manner similar to a conventional stepping motor or a permanent magnet synchronous motor. Complete suspension and controlled rotation of the horizontal axial float is thereby achieved, becoming a so-called "suspension rotor".

In practice, as long as there are more than three such radially magnetized permanent magnets, and the magnetic field orientations of these permanent magnets are equiangularly distributed on the radial circumference of the float, and are matched with the corresponding driving coils and energizing modes of the rotary driving coil assembly 10, the basic function of rotating the float can be satisfied. In practice, it is necessary to determine the requirements and control of the rotational stability in combination with the characteristics of the driving device. If a light sleeve made of non-magnetic material is added outside the float, the suspension, rotation demonstration and ornamental effect can be further improved (figure 10).

As shown in fig. 11, the system controller of the magnetic levitation demonstration system of the present invention comprises a levitation control unit, a levitation driving circuit, a rotation control unit and a rotation driving circuit; wherein, the suspension control unit and the rotation control unit can use a singlechip. The three-dimensional position information (including vertical position information, radial position information, and axial position information) of the float, which is sent by the position sensor 12, is all transmitted to the float control unit, which is also the main basic data source of the float-suspended, follow-up state. The levitation control unit receives the detection data of the position sensor 12 in real time, obtains the energizing rule or state required by each vertical and radial coil in the positioning coil group 7 through the processing of corresponding PID algorithm and the like, outputs the energizing rule or state to the levitation driving circuit, and drives the corresponding radial positioning coil and/or axial positioning coil in the positioning coil group 7 after power amplification so as to adjust the position of the floater, so that the floater can stably levitate.

The axial position information of the position sensor 12 is also simultaneously sent to the rotation control unit in order to automatically activate the float rotation function after obtaining a signal that the float is in place axially and normally suspended. The float rotation mode can be set in advance in a program, and can be set or directly controlled by a manual mode. After receiving the instruction sent by the rotation control unit and amplifying the power, the rotation driving circuit adjusts the direction and intensity of exciting currents of four coils in the rotation driving coil group 10 to determine the action mode of stepping rotation or continuous rotation of the floater, and the rotating speed and rotation direction of the floater, thereby obtaining the optimal demonstration or ornamental effect.

Claims (10)

1. A magnetic suspension demonstration system for displaying horizontal rotating shaft state comprises a stator and a floater, and is characterized in that,

the stator comprises a bottom plate, a left bracket and a right bracket which are arranged on the bottom plate, a floater traction coil which is arranged on the left bracket, a positioning coil group and a position sensor which are arranged on the right bracket, a rotary driving coil group which is arranged in the middle of the bottom plate, and a left end lifting magnet and a right end lifting magnet which are arranged on the bottom plate;

the floater comprises a horizontally arranged shaft rod, a rotary magnet group which is connected to the middle of the shaft rod in a penetrating way, and a left end suspension magnet and a right end suspension magnet which are arranged at the end part of the shaft rod;

the left end suspension magnet is vertically opposite to the left end lifting magnet, and the right end suspension magnet is vertically opposite to the right end lifting magnet and is used for generating magnetic repulsive force for lifting the floater; the magnets in the rotary magnet group are in one-to-one correspondence with the coils in the rotary driving coil group and are opposite up and down, so as to generate driving force for rotating the floater.

2. The magnetic levitation demonstration system for displaying a horizontal rotation shaft state according to claim 1, wherein the left end lifting magnet and the right end lifting magnet are formed by arranging two cylindrical magnets side by side at intervals; the two cylindrical magnets are axially magnetized, and the magnetization directions are consistent, so that stable and uniform lifting magnetic fields are formed in the middle parts of the two cylindrical magnets.

3. The magnetic levitation demonstration system for displaying the horizontal rotation shaft state according to claim 2, wherein the left end levitation magnet is a cylindrical magnet, is axially magnetized, and has the same magnetizing direction as the pair of magnets in the left end lifting magnet; the right end suspension magnet is a cylindrical magnet, is axially magnetized, and has the same magnetizing direction as that of the magnet pair in the right end lifting magnet.

4. The magnetic levitation demonstration system for displaying a horizontal rotating shaft state according to claim 1, wherein the positioning coil group comprises four coils with the same physical structure and electrical parameters, the four coils are distributed on the upper, lower, left and right directions of the position sensor, the four coils are divided into an upper group, a lower group and a left group, the two coils in each group are connected in series or in parallel, and the directions of energizing currents are opposite.

5. The magnetic levitation demonstration system for displaying horizontal rotation axis of claim 4, wherein the position sensor is the same as four coils in the positioning coil group in terms of distance, and the height of the position sensor protruding from the support plate surface is half of the height of the coils.

6. The magnetic levitation demonstration system for displaying a horizontal rotation shaft state according to claim 1, wherein the rotary magnet group comprises at least three annular permanent magnets which are radially magnetized and are connected and fixed on the shaft rod in a penetrating manner at equal intervals; the magnetic field directions of the permanent magnets are distributed at equal angles on the radial circumference of the shaft rod, namely, the permanent magnets are equally distributed with the angles of the circumferential angles of the floats in the respective magnetic pole direction sequence.

7. The magnetic levitation demonstration system for displaying a horizontal rotation axis according to claim 1, wherein the rotary driving coil set comprises coils having the same number as the permanent magnets in the rotary magnet set, all the coils being arranged on the base plate in a straight line in a longitudinal direction, one coil being opposite to one permanent magnet in a vertical position.

8. The magnetic levitation demonstration system for displaying a horizontal rotation axis state of claim 1, wherein a set-up interval between the left-end levitation magnet and the right-end levitation magnet is not equal to a set-up interval between the left-end lifting magnet and the right-end lifting magnet.

9. A magnetic levitation demonstration system for displaying a horizontal rotation axis state as claimed in claim 1 wherein the coils in the rotation driving coil group are linearly arranged along the axial direction of the float.

10. A magnetic levitation demonstration system for displaying a horizontal rotation axis state according to claim 1 wherein the permanent magnets in the rotating magnet group are installed in a spiral manner according to their magnetic pole directions.