CN109268391B - Multi-coil axial magnetic bearing for magnetic suspension stable platform - Google Patents

Abstract

A multi-coil axial magnetic bearing for a magnetic suspension stable platform is composed of a "mountain"-shaped stator and a "U"-shaped rotor, wherein the "mountain"-shaped stator is composed of three stator magnetic poles, and the middle stator magnetic pole is wound with a stator Bias coil and stator control coil; the "U"-shaped rotor is composed of three rotor magnetic poles, wherein the first rotor magnetic pole is wound with the first rotor control coil, and the third rotor magnetic pole is wound with the second rotor control coil; The center line coincides with the center line of the magnetic poles of the middle stator. There are eight sets of "mountain"-shaped stators and "U"-shaped rotors in the circumferential direction, of which four sets of "mountain"-shaped stators and "U"-shaped rotors are placed Above the thrust plate, and placed along the +X, -X, +Y, -Y directions; the other four groups of "mountain"-shaped stators and "U"-shaped rotors are placed under the thrust plate correspondingly. The structure can greatly reduce the volume and weight of the magnetic bearing of the existing structure.

Description

A multi-coil axial magnetic bearing for a magnetic suspension stable platform

technical field

The invention relates to a non-contact magnetic suspension bearing, in particular to a large bearing capacity split limited-angle multi-coil axial magnetic bearing, which can be used as a non-contact support with limited rotation angles such as satellite platforms, airborne inertial stabilization platforms, etc., and is especially suitable for Non-contact support for magnetically levitated inertial stabilized platforms.

Background technique

Commonly used magnetic suspension bearings are divided into electromagnetic bias type and hybrid magnetic suspension bearing with permanent magnet bias and electromagnetic control. The former uses bias current to generate bias magnetic field, which has the advantages of adjustable stiffness and damping; the latter uses permanent magnet to replace current to generate bias The magnetic field, the magnetic field generated by the permanent magnet bears the main bearing capacity, and the electromagnetic field provides the auxiliary regulating bearing capacity, which has the advantages of low power consumption and so on. According to the direction of bearing capacity, magnetic bearings are divided into radial magnetic bearings and axial magnetic bearings. For the existing axial magnetic bearing, the invention patent 200510011272.2 discloses a low-power permanent magnet biased axial magnetic bearing structure, which uses the second air gap to decouple the electromagnetic magnetic circuit from the permanent magnet magnetic circuit, and the invention patent 201510585671.3 discloses An asymmetrical permanent magnet offset axial magnetic bearing is proposed, which adopts a double U-shaped stator core, and uses asymmetric annular permanent magnets with different magnetomotive force in the positive Z direction and the negative Z direction to generate static loads with different axial directions in the two directions. However, the axial magnetic bearings described in these two structures are single-degree-of-freedom magnetic bearings, that is, they can only generate bearing force in the axial direction; while the invention patent 200710098748.X discloses a permanent magnetic offset axial magnetic bearing Bearing, invention patent 200710098749.4 discloses an axial magnetic bearing for a magnetic suspension flywheel. These two types of magnetic bearings divide the axial magnetic bearing into four groups of magnetic poles on the circumference along the X and Y directions. The direction of the current can realize the control of the axial translation degree of freedom and the two radial deflection degrees of freedom of the rotor. However, when applied to an inertial platform with a large diameter and a large size and a large bearing capacity such as an inertial platform carrying a 500kg camera load, there is a problem that the large diameter of the platform leads to a significant increase in the size of the bearing and a significant increase in weight.

SUMMARY OF THE INVENTION

The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, for a mechanism with limited small rotation angle such as an inertial stable platform, a split-type multi-coil capable of axial translation and radial torsion control is provided. Axial magnetic bearing.

The technical solution of the present invention is: a multi-coil axial magnetic bearing for a magnetic suspension stable platform, which is composed of a "mountain"-shaped stator (1) and a "U"-shaped rotor (2), wherein the "mountain"-shaped stator It consists of an outer stator pole, a middle stator pole and an inner stator pole, wherein the middle stator pole is wound with a stator bias coil (31) and a stator control coil (32). The heights of the outer stator poles and the inner stator poles of the "-shaped stator (1) in the radial direction are equal; the "U"-shaped rotor is composed of a first rotor magnetic pole and a second rotor magnetic pole, wherein the first rotor magnetic pole is wound with the first rotor pole. A rotor control coil (4), the second rotor magnetic pole is wound with a second rotor control coil (5), the center line of the "U"-shaped rotor (2) coincides with the center line of the middle stator magnetic pole, and a total of Eight sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2), of which four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are placed above the thrust plate , the other four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are placed under the thrust disc, and the four sets of "mountain"-shaped stators (1) and "U"-shaped stators (1) above and below the thrust disc The ""-shaped rotor (2) is placed along the +X, -X, +Y, -Y directions; the four groups of "mountain"-shaped stators (1) and the "U"-shaped rotor (2) form axial magnetism gap (6). The stator bias coil (31) is supplied with a bias current to form a bias magnetic field in the axial magnetic air gap (6), and the stator control coil (32) is supplied with a control current to realize the translational control of the thrust plate along the Z direction. A rotor control coil (4) and a second rotor control coil (5) are supplied with control current to realize the deflection control of the thrust disk along the X and Y directions.

The upper part of the thrust plate can also be composed of eight groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2), which are evenly distributed along the circumferential direction, among which four groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are formed. The U"-shaped rotor (2) is placed along the +X, -X, +Y, -Y directions; the lower part of the thrust plate can also be composed of eight groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2). , corresponding to the eight sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) above the thrust plate, and the "mountain"-shaped stators (1) and "U"-shaped rotors (2) above the thrust plate An axial magnetic air gap (6) is formed between the rotors (2) and an axial magnetic air gap (6) is formed between the "mountain"-shaped stator (1) and the "U"-shaped rotor (2) below the thrust disk not equal.

The upper part of the thrust plate can also be composed of eight groups of "mountain"-shaped stators and "U"-shaped rotors, which are evenly distributed along the circumferential direction. -X, +Y, -Y directions; the bottom of the thrust disc can also be composed of four sets of "mountain"-shaped stators and "U"-shaped rotors, which are connected with the four sets above the thrust disc along the lines of +X, -X, +Y, -The "mountain"-shaped stator placed in the Y direction and the "U"-shaped rotor are placed correspondingly.

The materials of the "mountain"-shaped stator and the "U"-shaped rotor are 1J50, 1J22 or electrical pure iron.

The material of the thrust disc is a non-magnetic material such as aluminum alloy or titanium alloy.

The principle of the above scheme is: the present invention forms a bias magnetic field between the "mountain"-shaped stator and the "U"-shaped rotor by passing current into the "mountain"-shaped stator bias coil, and the "mountain"-shaped stator controls The current control in the coil realizes the axial translation control of the thrust disk; the deflection of the thrust disk along the radial X and Y directions is realized through the current control of the first rotor control coil and the second rotor control coil of the "U"-shaped rotor control. The electromagnetic magnetic circuit after the "mountain"-shaped stator bias coil and the control coil of the present invention are energized are: the middle stator magnetic pole of the "mountain"-shaped stator, the air gap, the middle part of the "U"-shaped rotor, the "U"-shaped rotor The magnetic poles on both sides of the rotor (i.e. the first rotor magnetic pole and the second rotor magnetic pole), the air gap, the magnetic poles on both sides of the "mountain"-shaped stator (that is, the outer stator magnetic pole and the inner stator magnetic pole), back to the "mountain" word The middle stator pole of the type stator is shown in Figure 3. The electromagnetic magnetic circuit of the first rotor control coil of the "U"-shaped rotor of the present invention is divided into two parts. The corresponding magnetic poles (that is, the inner stator magnetic poles), the middle stator magnetic poles of the "mountain"-shaped stator, the air gap, and the "U"-shaped rotor; the second part of the magnetic circuit is: the first rotor magnetic pole of the "U"-shaped rotor, The air gap, the corresponding magnetic pole of the "mountain"-shaped stator (that is, the inner stator magnetic pole), the outer stator magnetic pole of the "mountain"-shaped stator, the air gap, and the second rotor magnetic pole of the "U"-shaped rotor. The road is shown in Figure 4. In the same way, the electromagnetic magnetic circuit of the second rotor control coil of the "U"-shaped rotor of the present invention is divided into two parts. The first magnetic circuit is: the magnetic pole of the second rotor of the "U"-shaped rotor, the air gap, the The corresponding magnetic poles of the shape stator (ie the outer stator poles), the middle stator poles of the "mountain" shape stator, the air gap, and the "U" shape rotor; the second part of the magnetic circuit is: the second part of the "U" shape rotor Rotor magnetic poles, air gaps, the corresponding magnetic poles of the "mountain"-shaped stator (that is, the outer stator magnetic poles), the inner stator magnetic poles of the "mountain"-shaped stator, the air gap, and the first rotor magnetic pole of the "U"-shaped rotor. It should be noted that when the first rotor control coil and the second rotor control coil have the same number of turns, and the axial gap between the inner stator poles of the "mountain"-shaped stator and the first rotor magnetic poles of the "U"-shaped rotor is the same as When the axial gap between the outer stator poles of the "mountain"-shaped stator and the second rotor magnetic pole of the "U"-shaped rotor is equal, the magnetic flux generated at the second rotor magnetic pole when the first rotor control coil is energized is the same as the second rotor magnetic pole. The rotor control coils pass currents of equal magnitude and the same direction, and the magnetic fluxes generated at the first rotor magnetic poles are equal in magnitude and opposite in direction, so the two cancel each other out. When the control coils are fed with currents of equal magnitude and direction at the same time, the magnetic circuit is the same as in Figure 3. When the "mountain"-shaped stator control coil and the "U"-shaped rotor control the first rotor control coil and the second rotor control After the coils are energized at the same time (the currents are equal in magnitude and in the same direction), the combined magnetic circuit is shown in Figure 5, where the solid line represents the magnetic circuit diagram when the "mountain"-shaped stator control coil is energized, and the dotted line represents "U" The magnetic circuit diagram after the first rotor control coil and the second rotor control coil of the font-shaped rotor are energized at the same time (the currents are equal in magnitude and direction); Figure 5 shows that the first rotor control coil and the second rotor control coil are energized to generate magnetic flux When superimposed with the magnetic flux generated by the energization of the stator control coil, and vice versa.

When applying the axial magnetic bearing of the present invention, there are usually eight groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2) in the circumferential direction, among which four groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2). The stator (1) and the "U"-shaped rotor (2) are placed above the thrust plate, and the other four sets of "mountain"-shaped stators (1) and the "U"-shaped rotor (2) are placed under the thrust plate. The four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) above and below the thrust plate are placed along the +X, -X, +Y, -Y directions, as shown in Fig. A bias current is passed into the bias coil in the group "mountain"-shaped stator (1), and the current forms a bias magnetic field at the air gap between the "mountain"-shaped stator and the "U"-shaped rotor. When the thrust disc moves in the axial-z direction, the current in the same direction as the bias current is passed through the stator control coil in the "mountain"-shaped stator above the thrust disc, so that it is in the "mountain" shape. The magnetic field in the magnetic air gap between the stator and the "U"-shaped rotor is enhanced, and at the same time, the current in the opposite direction to the bias current is passed into the stator control coil in the "mountain"-shaped stator under the thrust plate, so that it is in the opposite direction of the bias current. The magnetic field in the magnetic air gap between the "mountain"-shaped stator and the "U"-shaped rotor weakens, causing the thrust disk to move in the +z direction, and then return to the equilibrium position, and vice versa. When the thrust plate deflects in the +x direction, the magnetic gap between the "mountain"-shaped stator and the "U"-shaped rotor placed above the thrust plate in the +y direction becomes smaller, and the thrust plate is placed in the +y direction. The magnetic gap between the "mountain"-shaped stator and the "U"-shaped rotor below becomes larger, and the magnetic gap between the "mountain"-shaped stator and the "U"-shaped rotor above the thrust plate is placed along the -y direction. When it becomes larger, the magnetic gap between the "mountain"-shaped stator and the "U"-shaped rotor under the thrust disk is placed along the -y direction, and the magnetic gap between the "U"-shaped rotor becomes smaller. At this time, the "U" shape under the thrust disk is placed along the +y direction. The rotor and the first rotor coil and the second rotor coil in the "U"-shaped rotor placed above the thrust disk along the -y direction are supplied with current, so that the "U"-shaped rotor has a suction effect on the "mountain"-shaped stator. Makes the thrust disc produce a restoring force in the -x direction, thereby reaching equilibrium, and vice versa.

The upper and lower parts of the thrust plate of the present invention can also be composed of eight groups of "mountain"-shaped stators and "U"-shaped rotors, which are evenly distributed along the circumferential direction, as shown in Fig. 7, among which four groups of "mountain"-shaped rotors The stator and the "U"-shaped rotor are placed along the +X, -X, +Y, -Y directions; the "mountain"-shaped stator and the "U" character placed along the +X, -X, +Y, -Y directions The rotor controls the deflection degree of freedom of the thrust plate, that is, the two deflection degrees of freedom of the thrust plate along the X and Y directions. The weight of the load on it controls the translational freedom of the thrust disc in the Z direction; in order to further reduce the weight, there are two ways to achieve it, one way is to design the eight groups above the thrust disc" The axial magnetic air gap between the "mountain"-shaped stator and the "U"-shaped rotor is smaller than the axial magnetic air gap between the eight groups of "mountain"-shaped stators and the "U"-shaped rotor under the thrust disc. It can reduce the coil current when the suspension is axially loaded. In practical application, considering the axial length and load structure of the magnetic levitation device, there are usually two upper and lower thrust discs, so when the structure of the present invention is designed, the eight groups of "mountain"-shaped stators are placed on the lower thrust disc. Above or below, a load such as a camera is placed above the upper thrust plate. Another way is to use an asymmetric method above and below the thrust disc, that is to say, eight sets of "mountain"-shaped stators and "U"-shaped rotors are used above the thrust disc, and they are evenly distributed along the circumference. The bottom of the disk is composed of four groups of "mountain"-shaped stators and "U"-shaped rotors. As shown in Figure 9, the four groups of "mountain"-shaped stators and "U"-shaped rotors under the thrust disk are connected to the upper edge of the thrust disk. The "mountain"-shaped stator and the "U"-shaped rotor placed in the +X, -X, +Y, -Y directions are placed correspondingly.

Compared with the prior art, the advantages of the present invention are: the axial magnetic bearing of the present invention has a "mountain"-shaped stator and a "U"-shaped rotor, and both the stator and the rotor are designed with coils, and the "mountain"-shaped stator The design of the bias coil greatly improves the utilization space and utilization of the coil, and at the same time improves the bearing capacity and deflection control ability of the bearing. The first rotor control coil and the second rotor control coil of the "U"-shaped rotor control the deflection movement of the thrust disk in the X and Y directions, which can greatly reduce the volume and weight of the existing magnetic bearing structure.

Description of drawings

1 is an axial cross-sectional view of an axial magnetic bearing of the present invention;

Fig. 2 is the axial magnetic bearing "mountain" type stator and "U" type rotor structural diagram of the present invention;

Fig. 3 is the magnetic circuit diagram of the axial magnetic bearing "mountain"-shaped stator bias coil or stator control coil after electrification of the present invention;

Fig. 4 is the magnetic circuit diagram after the first rotor control coil of the axial magnetic bearing "U"-shaped rotor of the present invention is energized;

Fig. 5 is the magnetic circuit diagram after the axial magnetic bearing "mountain" shape stator control coil and "U" shape rotor first rotor control coil and second rotor control coil are energized at the same time;

Fig. 6 is the axial magnetic bearing structure of the symmetrical structure of the present invention, in which there are 4 sets of "mountain"-shaped stators and "U"-shaped rotors above and below the thrust plate. ;

Fig. 7 is the axial magnetic bearing structure of the symmetrical structure of the present invention, wherein there are 8 groups of "mountain"-shaped stators and "U"-shaped rotors above and below the thrust plate;

Fig. 8 is the axial magnetic bearing structure of the symmetrical structure of the present invention, wherein a total of 8 groups of "mountain"-shaped stators placed above and below the thrust disks placed along the +X, -X, +Y, -Y directions are not wound around Sub-control coils; the remaining 8 groups of "U"-shaped rotors are not wound with the first rotor control coil and the second rotor control coil;

Fig. 9 is the axial magnetic bearing structure of the asymmetric structure of the present invention, wherein there are 8 groups of "mountain"-shaped stators and "U"-shaped rotors above the thrust plate, and 4 groups of "mountain"-shaped stators and "U"-shaped rotors are arranged below the thrust plate. ” type rotor;

Fig. 10 is the axial magnetic bearing structure of the asymmetric structure of the present invention, wherein there are 8 groups of "mountain"-shaped stators and "U"-shaped rotors above the thrust plate, and the lines along +X, -X, +Y, -Y The "mountain"-shaped stator placed in the direction is not wound with the stator control coil, and the remaining 4 groups of "U"-shaped rotors are not wound with the first rotor control coil and the second rotor control coil; there are 4 groups of "mountain" type below. The stator and the "U"-shaped rotor are placed along the +X, -X, +Y, -Y directions, and the "mountain"-shaped stator is not wound around the stator control coil.

Detailed ways

As shown in Figures 1 and 2, a multi-coil axial magnetic bearing for a magnetic suspension stable platform is composed of a "mountain"-shaped stator (1) and a "U"-shaped rotor (2). The stator consists of outer stator magnetic poles, middle stator magnetic poles and inner stator magnetic poles, wherein the middle stator magnetic pole is wound with a stator bias coil (31) and a stator control coil (32), and the height of the stator bias coil (31) in the radial direction is the same as " The heights of the outer stator magnetic poles and the inner stator magnetic poles of the "mountain"-shaped stator (1) in the radial direction are equal; the "U"-shaped rotor is composed of a first rotor magnetic pole and a second rotor magnetic pole, wherein the first rotor magnetic pole is wound with a The first rotor control coil (4), the second rotor magnetic pole is wound with the second rotor control coil (5), the center line of the "U"-shaped rotor (2) coincides with the center line of the middle stator magnetic pole, and they are placed together in the circumferential direction There are eight sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2), of which four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are placed on the thrust plate. Above, the other four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are placed under the thrust disc, and the four sets of "mountain"-shaped stators (1) and " The U"-shaped rotor (2) is placed along the +X, -X, +Y, -Y directions; axial magnetic fields are formed between the four groups of "mountain"-shaped stators (1) and the "U"-shaped rotor (2). Air gap (6), as shown in Figure 6;

In a specific application, the stator bias coils (31) in the four groups of "mountain"-shaped stators (1) above the thrust disk and the four groups of "mountain"-shaped stators (1) under the thrust disk The stator bias coil (31) is supplied with a certain bias current (usually 1A to 3A), thereby generating a bias magnetic field in the axial magnetic air gap between the "mountain"-shaped stator and the "U"-shaped rotor , when the thrust disc is offset in the -Z direction, then the stator control coils (32) in the four groups of "mountain"-shaped stators (1) above the thrust disc are connected in the same direction as the stator bias coil (31) The magnetic field generated at the axial magnetic air gap is in the same direction as the magnetic field generated by the stator bias coil (3), and the stator in the four groups of "mountain"-shaped stators (1) under the thrust plate controls The coil (32) is fed with a control current opposite to the direction of the stator bias coil (31), so that the magnetic field generated at the axial magnetic air gap is in the opposite direction to the magnetic field generated by the stator bias coil (3). Generates a restoring force in the +Z direction. When the thrust disc is deflected along the +Y direction, that is, the "mountain"-shaped stator (1) and the "U"-shaped rotor (2) placed above the thrust disc along +X and the bottom of the thrust disc are placed along -X The axial magnetic gap between the "mountain"-shaped stator (1) and the "U"-shaped rotor (2) is reduced, while the "mountain"-shaped stator (1) and " The axial magnetic gap between the U"-shaped rotor (2) and the "mountain"-shaped stator (1) and the "U"-shaped rotor (2) placed under the thrust disk along +X increases, at this time, the thrust disk The first rotor control coil and the second rotor control coil in the "U"-shaped rotor (2) placed along the +X above and the "U"-shaped rotor (2) placed along the -X below the thrust plate are all connected to the size Currents in the same direction and the same direction as the stator bias coil ( 31) The direction of the incoming bias current is the same, so that the magnetic field generated at the axial magnetic air gap is the same as the "mountain"-shaped stator (1) placed along +X above the thrust plate and the one placed along -X below the thrust plate. The bias current in the stator bias coil (31) of the middle "mountain"-shaped stator (1) produces the opposite direction of the magnetic field at the axial magnetic air gap; The rotor (2) and the first rotor control coil (4) and the second rotor control coil (5) in the "U"-shaped rotor (2) placed under the thrust plate along +X are all passed through the current of equal size and direction. , which is connected to the stator bias coil (31) in the "mountain"-shaped stator (1) placed along the -X above the thrust plate and the stator bias coil (31) in the "mountain"-shaped stator (1) placed along the +X under the thrust plate. The direction of the bias current is opposite, so that the magnetic field generated at the axial magnetic air gap is the same as the "mountain"-shaped stator (1) placed along the -X above the thrust plate and the middle "mountain" placed along the +X under the thrust plate. The direction of the magnetic field generated by the stator bias coil (31) of the type stator (1) is the same, and at this time, the thrust plate receives a moment along the -Y direction to maintain balance. vice versa.

The upper and lower parts of the thrust plate of the present invention can also be composed of eight groups of "mountain"-shaped stators and "U"-shaped rotors, which are evenly distributed along the circumferential direction, as shown in Fig. A set of "mountain"-shaped stators and "U"-shaped rotors placed along the +X, -X, +Y, -Y directions control the deflection degrees of freedom of the thrust disk, that is, the two deflections of the thrust disk along the X and Y directions degrees of freedom, while the other four sets of "mountain"-shaped stators and "U"-shaped rotors above and below the thrust disc control the axial translation degrees of freedom of the thrust disc; in order to further reduce the bearing weight, four sets of The middle stator magnetic poles of the "mountain"-shaped stators placed along the +X, -X, +Y, -Y directions can only be wound with a bias coil, not a control coil. At this time, the bias coil can occupy the original bias. The volume of the set coil and the control coil can greatly improve the translation bearing capacity. At the same time, the remaining four groups of "U"-shaped rotors are not wound with the first rotor control coil and the second rotor control coil, which are used to bear the thrust plate. and the weight of the load placed on it, that is, the translational degree of freedom of the control thrust plate along the Z direction, as shown in Figure 8; in order to further reduce the weight, there are two ways to achieve, one way is to design The axial magnetic air gap between the eight sets of "mountain"-shaped stators and the "U"-shaped rotors above the thrust disc can be made smaller than that between the eight sets of "mountain"-shaped stators and the "U"-shaped rotors below the thrust disc. The axial magnetic air gap between them can reduce the coil current when the suspension is axially loaded. In practical application, considering the axial length and load structure of the magnetic levitation device, there are usually two upper and lower thrust discs, so when the structure of the present invention is designed, the eight groups of "mountain"-shaped stators are placed on the lower thrust disc. Above or below, a load such as a camera is placed above the upper thrust plate. Another way is to use an asymmetric method above and below the thrust disc, that is to say, eight sets of "mountain"-shaped stators and "U"-shaped rotors are used above the thrust disc, and they are evenly distributed along the circumference. The bottom of the disk is composed of four groups of "mountain"-shaped stators and "U"-shaped rotors. As shown in Figure 9, the four groups of "mountain"-shaped stators and "U"-shaped rotors under the thrust disk are connected to the upper edge of the thrust disk. The "mountain"-shaped stator and the "U"-shaped rotor placed in the +X, -X, +Y, -Y directions are placed correspondingly. The "mountain"-shaped stator placed in the +Y and -Y directions is not wound with the stator control coil, and the remaining 4 groups of "U"-shaped rotors are not wound with the first rotor control coil and the second rotor control coil; at the same time, under the thrust plate The four groups of "mountain"-shaped stators and "U"-shaped rotors are placed along the +X, -X, +Y, -Y directions, and the "mountain"-shaped stators are not wound around the stator control coil, as shown in Figure 10 shown.

The materials of the "mountain"-shaped stator (1) and the "U"-shaped rotor (2) are 1J50, 1J22 or electrical pure iron.

The material of the thrust disc is aluminum alloy or titanium alloy.

Contents that are not described in detail in the specification of the present invention belong to the prior art known to those skilled in the art.

Claims (5)

1. a multi-coil axial magnetic bearing for a magnetic suspension stable platform is characterized in that: it is composed of "mountain" type stator (1) and "U" type rotor (2), wherein "mountain" type stator is made up of outside The stator magnetic pole, the middle stator magnetic pole and the inner stator magnetic pole are formed, wherein the middle stator magnetic pole is wound with a stator bias coil (31) and a stator control coil (32). The heights of the outer stator poles and the inner stator poles of the type stator (1) in the radial direction are equal; the "U"-shaped rotor is composed of a first rotor pole and a second rotor pole, wherein the first rotor pole is wound with the first rotor The control coil (4), the second rotor magnetic pole is wound with the second rotor control coil (5), the center line of the "U"-shaped rotor (2) coincides with the center line of the middle stator magnetic pole, and eight groups are placed in the circumferential direction. "Mountain"-shaped stator (1) and "U"-shaped rotor (2), in which four sets of "Mountain"-shaped stator (1) and "U"-shaped rotor (2) are placed above the thrust plate, and in addition Four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are placed under the thrust disc, and four sets of "mountain"-shaped stators (1) and "U"-shaped stators (1) and "U" are placed above and below the thrust disc. The rotor (2) is placed along the +X, -X, +Y, -Y directions; an axial magnetic air gap ( 6); the stator bias coil (31) is fed with a bias current to form a bias magnetic field in the axial magnetic air gap (6), and the stator control coil (32) is fed with a control current to realize the translational movement of the thrust plate along the Z direction Control, the first rotor control coil (4) and the second rotor control coil (5) supply control current to realize the deflection control of the thrust disk along the X and Y directions. 2. The axial magnetic bearing according to claim 1, characterized in that: the upper part of the thrust disk can also be composed of eight groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2). The directions are evenly distributed, among which four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are placed along the +X, -X, +Y, -Y directions; "-shaped stator (1) and "U"-shaped rotor (2) are placed in correspondence with the eight groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2) above the thrust plate, and the thrust An axial magnetic air gap (6) is formed between the "mountain"-shaped stator (1) above the disk and the "U"-shaped rotor (2), and the "mountain"-shaped stator (1) and the "U"-shaped stator (1) below the thrust disk The axial magnetic air gaps (6) formed between the "shaped rotors (2) are not equal. 3. The axial magnetic bearing according to claim 1, characterized in that: the upper part of the thrust disk can also be composed of eight groups of "mountain"-shaped stators (1) and "U"-shaped rotors (2). The directions are evenly distributed, among which four sets of "mountain"-shaped stators (1) and "U"-shaped rotors (2) are placed along the +X, -X, +Y, -Y directions; there can also be four sets of "mountain" under the thrust plate. "-shaped stator (1) and "U"-shaped rotor (2), together with the four sets of "mountain"-shaped stators (1) placed along the +X, -X, +Y, -Y directions above the thrust plate It is placed corresponding to the "U"-shaped rotor (2). 4. The axial magnetic bearing according to claim 1, wherein the material of the "mountain"-shaped stator (1) and the "U"-shaped rotor (2) is 1J50, 1J22 or electrical pure iron . 5 . The axial magnetic bearing according to claim 1 , wherein the material of the thrust plate is aluminum alloy or titanium alloy. 6 .

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