Gas-magnetic hybrid suspension unit for micro-low gravity based on magnetic porous medium

Abstract

The micro-low gravity gas-magnetic hybrid suspension unit comprises a shell, a stepped hole is formed in the shell in the axial direction of the center, a bearing column, a permanent magnet, a circular plate with a main gas supply groove and an inner porous medium are sequentially arranged in the shell from bottom to top, and the radial peripheral sizes of the inner porous medium, the circular plate and the permanent magnet are consistent; a magnetic isolation circular ring is embedded between the permanent magnet and the shell, an auxiliary air supply groove is formed in the upper-layer step face of the step hole, an outer porous medium is glued to the upper face of the auxiliary air supply groove, the upper surfaces of the magnetic isolation circular ring, the inner porous medium, the outer porous medium and the shell are the same plane, and the plane is covered with a working plane plate. Air supply holes sequentially penetrating through the auxiliary air supply grooves, the magnetic isolation circular rings and the main air supply grooves are formed in the outer portion of the shell in the radial direction of the shell. The ultimate bearing capacity of the gas-magnetic hybrid suspension unit can be increased, and the transverse resistance can be weakened.

Description

Technical Field

[0001] The present invention relates to a suspension device used in micro-low gravity experiments, and in particular to an air-magnetic hybrid suspension unit which uses an air bearing based on a magnetic porous material as a part of the magnetic circuit. Background Art

[0002] In the gravitational environment outside the earth, large space mechanisms tend to use lighter materials and structures with relatively low strength requirements to adapt to the slightly low-gravity space deployment conditions. The motion laws and nonlinear dynamic characteristics of these mechanisms in space show significant differences compared to the standard gravity environment of the earth. In order to ensure the successful execution of space missions, it is particularly important to carry out comprehensive and in-depth ground zero-gravity simulation tests on large deployment mechanisms. At present, the suspension method is the mainstream choice in simulation test systems, but the suspension method has the disadvantages of low system accuracy, poor dynamic performance, poor versatility, and high cost.

[0003] In order to overcome the shortcomings of traditional suspended simulation devices, the advantages of air flotation and suspension methods are combined, and an inverted suspended gas-magnetic hybrid ground zero-gravity unloading scheme is adopted. The gas-magnetic hybrid suspension unit combines gas zero-friction lubrication technology with magnetic suspension technology, making full use of the ultra-micro friction characteristics of gas lubrication, greatly reducing the system interference torque and improving the simulation accuracy. At the same time, combined with magnetic suspension technology, free movement without trajectory constraints in a two-dimensional plane is realized, thereby fully covering the test needs of various space mechanisms under different deployment trajectories, and thus building a universal ground test platform.

[0004] The existing gas-magnetic hybrid suspension unit is a gas-magnetic separation structure, including an electromagnetic permanent magnet hybrid unit 15, which is connected to the upper end face of the bottom shell 13 by threads, and the bottom shell 13 is connected to the lower end face of the gas bearing shell 14 by threads. The upper end face of the gas bearing shell 14 is glued with a porous graphite plate 12. The electromagnetic permanent magnet hybrid unit 15 generates a magnetic attraction force to adsorb on the working plane of the magnetic conductive plate 11, and the porous graphite plate 12 generates an air floating repulsion force to suspend the bearing. The above-mentioned existing gas-magnetic hybrid suspension unit is characterized in that the electromagnetic permanent magnet hybrid unit 15 is separated from the gas bearing, Figure 6 The figure shows that the height difference between the electromagnetic permanent magnet mixing unit 15 and the gas bearing is H. The electromagnetic permanent magnet mixing unit 15 is in the center, and the porous graphite plate 12 surrounds the magnetic unit in an annular shape. The porous graphite plate 12 has no magnetic conductivity, and there is no magnetic path through the gas bearing part. This design has the following disadvantages:

[0005] (1) Considering the design limitation of the size of the air-magnetic bearing, under a certain area limitation, the electromagnetic permanent magnet hybrid unit 15 and the air bearing working area are contradictory, that is, when the area of ​​the electromagnetic permanent magnet hybrid unit 15 increases, the magnetic attraction is enhanced, but the working area of ​​the porous graphite plate 12 decreases, and the air buoyancy decreases, resulting in the inability of the gas thrust bearing to work under no-load; when the area of ​​the electromagnetic permanent magnet hybrid unit decreases, the magnetic attraction decreases, resulting in a decrease in the maximum suspension force of the air-magnetic hybrid suspension unit. The above contradictions limit the bearing capacity of the air-magnetic hybrid suspension unit, making it difficult to withstand high-load conditions;

[0006] (2) The separation design of the electromagnetic permanent magnet hybrid unit 15 and the air bearing results in a limited area of ​​the magnetic unit, which makes it impossible to utilize all the area of ​​the air-magnetic unit. The magnetic field density is relatively high. When the air-magnetic hybrid suspension unit moves laterally, the magnetic plate cuts the magnetic flux lines to generate an induced current, and the lateral resistance interacting with the magnetic field is large, which is the Lenz's law effect. This resistance becomes an interference force in the micro-low gravity test and should be reduced as much as possible. Summary of the invention

[0007] In view of the above-mentioned prior art, in order to overcome the design defects of the current gas-magnetic hybrid suspension unit, increase the ultimate bearing capacity of the gas-magnetic hybrid suspension unit and reduce the lateral resistance, the present invention provides an gas-magnetic hybrid suspension unit for micro-low gravity based on a magnetic porous medium.

[0008] In order to solve the above technical problems, the present invention proposes an air-magnetic hybrid suspension unit for micro-low gravity based on a magnetic porous medium, comprising an outer shell, wherein a stepped hole is provided in the inner shell along the central axis; the bottom layer of the stepped hole is a central inner groove, and a bearing column is embedded in the central inner groove; a permanent magnet is glued between the middle step surface of the stepped hole and the outer surface of the bearing column, a circular plate with a main air supply groove is glued on the upper surface of the permanent magnet, and an inner porous medium is glued on the upper surface of the circular plate, and the radial outer circumferential dimensions of the inner porous medium, the circular plate and the permanent magnet are consistent; A magnetic isolation ring is embedded between the permanent magnet and the outer shell; an auxiliary air supply groove is provided on the upper step surface of the stepped hole, and an outer porous medium is glued on the upper surface of the auxiliary air supply groove; the upper surface of the magnetic isolation ring, the upper surface of the inner porous medium, the upper surface of the outer porous medium and the upper surface of the outer shell are in the same plane, and the plane is covered with a working plane plate; a connecting flange is fastened with bolts on the lower end surface of the outer shell, and a hanging ring is screwed into the lower end surface of the connecting flange; air supply holes are provided from the outside of the outer shell along the radial direction of the outer shell, which sequentially penetrate the auxiliary air supply groove, the magnetic isolation ring and the main air supply groove.

[0009] Furthermore, the gas-magnetic hybrid suspension unit for micro-low gravity of the present invention comprises:

[0010] The inner porous medium, the outer porous medium, the circular plate with the main air supply groove, the outer shell and the working plane plate are respectively used as a part of the magnetic circuit, and are all made of magnetic conductive materials. The magnetic conductive material constituting the inner porous medium or the outer porous medium is one of porous iron, porous nickel and porous iron-nickel soft magnetic alloy.

[0011] The magnetic conductive material constituting the circular plate with the main air supply groove, the shell or the working plane plate is a dense non-porous magnetic conductive material, which is one of industrial pure iron, iron-nickel soft magnetic alloy and silicon steel.

[0012] The magnetic circuit formed by the air-magnetic hybrid suspension unit for micro-low gravity is: the permanent magnet is placed at the rear of the main air supply groove, and the magnetic circuit generated by the permanent magnet passes through the circular plate made of magnetic conductive material with the main air supply groove, the inner porous medium and the working plane of the working plane plate in sequence, then reaches the outer porous medium and the outer shell and returns to the permanent magnet, thereby forming a complete circuit.

[0013] The magnetic isolation ring and the bearing column are both made of non-magnetic conductive materials to prevent the magnetic circuit from leaking out. The non-magnetic conductive material is one of aluminum, copper and ceramic.

[0014] The main gas supply groove and the auxiliary gas supply groove are both multi-stage annular grooves, and the multi-stage annular grooves are all connected to the gas supply hole. The gas supply hole is connected to the gas source, and the gas source is generated by an air compressor, and is sequentially connected to the gas storage tank, the filter and the pressure gauge through the gas pipe. The compressed gas is sent into the auxiliary gas supply groove and the main gas supply groove through the gas supply hole, and flows into the outer porous medium and the inner porous medium through the gas path formed by the multi-stage annular grooves of the auxiliary gas supply groove and the main gas supply groove. The throttling effect of the outer porous medium and the inner porous medium generates an air film on the surface of the working plane of the working plane plate, thereby reducing the direct contact between the surfaces, thereby reducing the lateral friction.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The present invention uses a magnetic porous medium, and for the first time uses the porous medium as a link in the magnetic circuit, and places the permanent magnet on the back of the gas bearing, which not only facilitates processing and improves the surface quality of the gas bearing, but also increases the working area of ​​the gas bearing, thereby increasing the total load-bearing capacity of the gas-magnetic hybrid suspension unit;

[0017] (2) The present invention uses a magnetic porous medium, and the surface of the entire gas bearing is also the working surface of the magnetic circuit, which reduces the magnetic field density while ensuring the overall size of the magnetic force, thereby weakening the lateral resistance caused by Lenz's law;

[0018] (3) The present invention adopts the design of inner and outer double porous media, so that the upper end surface of the magnetic isolation arc, the inner porous medium and the outer porous medium together form an air film plane, further increasing the bearing capacity of the air-magnetic hybrid suspension unit.

[0019] (4) The present invention designs a clear magnetic flux path, which effectively prevents magnetic flux leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structural decomposition of the first embodiment of the air-magnetic hybrid suspension unit for micro-low gravity of the present invention;

[0021] Figure 2 For the general Figure 1 A cross-sectional view of the air-magnetic hybrid suspension unit for micro-low gravity after the structure is assembled as shown;

[0022] Figure 3 for Figure 2 The magnetic circuit diagram of the air-magnetic hybrid suspension unit for micro-low gravity is shown;

[0023] Figure 4 for Figure 2 The force diagram of the working state of the air-magnetic hybrid suspension unit for micro-low gravity is shown;

[0024] Figure 5 It is a cross-sectional view of the second embodiment of the air-magnetic hybrid suspension unit for micro-low gravity of the present invention;

[0025] Figure 6 It is a structural schematic diagram of an air-magnetic hybrid suspension unit with an air-magnetic separation structure in the prior art.

[0026] Description of reference numerals in the figures:

[0027] 1- magnetic isolation ring 2- internal porous medium 3- circular plate 31- main air supply groove

[0028] 4-external porous medium 5-carrying column 6-permanent magnet 61-electromagnet

[0029] 62-coil 7-housing 71-center inner groove 72-upper step surface

[0030] 73- auxiliary air supply groove 74- middle step surface 75- air supply hole 8- connecting flange

[0031] 9-Lifting ring 10-Working plane plate 11-Magnetic plate 12-Porous graphite plate

[0032] 13- bottom shell 14- gas bearing shell 15- electromagnetic permanent magnet hybrid unit DETAILED DESCRIPTION

[0033] The present invention provides a design idea of ​​a gas-magnetic hybrid suspension unit for micro-low gravity based on a magnetically conductive porous medium. The porous medium is used as a link of the magnetic circuit, and the permanent magnet is placed on the back of the gas bearing. The upper end surfaces of the magnetic isolation ring, the inner porous medium and the outer porous medium are in the same plane, and can be processed in one piece. While improving the surface quality of the gas bearing, the working area of ​​the gas bearing is increased, thereby increasing the total load-bearing capacity of the gas-magnetic hybrid suspension unit. The magnetic circuit is expanded to the entire working surface, and the magnetic field density is reduced while ensuring the overall size of the magnetic force, thereby weakening the lateral resistance caused by Lenz's law.

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0035] like Figure 1 As shown, the present invention proposes an air-magnetic hybrid suspension unit for micro-low gravity based on magnetic porous medium, and its components mainly include: a magnetic isolation ring 1, an inner porous medium 2, a circular plate 3 with a main air supply groove 31, an outer porous medium 4, a bearing column 5, a permanent magnet 6, a shell 7, a connecting flange 8, a suspension ring 9 and a working plane plate 10, wherein the inner porous medium 2 is in the shape of a round cake, and the outer porous medium 4 is in the shape of a circular ring. The specific structure is as follows:

[0036] like Figure 1 and Figure 2 As shown, the housing 7 is provided with a stepped hole along the central axis. Figure 2 As shown, the bottom layer of the stepped hole is a central inner groove 71, and the bearing column 5 is embedded in the central inner groove 71; the permanent magnet 6 is glued between the middle step surface 74 of the stepped hole and the outer surface of the bearing column 5, the circular plate 3 with the main air supply groove 31 is glued on the top of the permanent magnet 6, and the inner porous medium 2 is glued on the top of the circular plate 3. The radial outer peripheral dimensions of the inner porous medium 2, the circular plate 3 and the permanent magnet 6 are consistent; the magnetic isolation ring 1 is embedded between the permanent magnet 6 and the shell 7; the upper step surface 72 of the stepped hole of the shell 7 is provided with a secondary air supply groove 73, and the outer porous medium 4 is glued on the secondary air supply groove 73. The upper surface of the magnetic isolation ring 1, the upper surface of the inner porous medium 2, the upper surface of the outer porous medium 4 and the upper surface of the shell 7 are the same plane, and the plane can be processed in one piece. The working plane plate 10 covers this plane. The lower end surface of the shell 7 is connected to the connecting flange 8 by bolts, and the lifting ring 9 is screwed in from the lower end surface of the connecting flange 8; from the outside of the shell 7, there are air supply holes 75 along the radial direction of the shell, which pass through the auxiliary air supply groove 73, the magnetic isolation ring 1 and the main air supply groove 31 in sequence.

[0037] The inner porous medium 2, the outer porous medium 4, the circular plate 3 with the main air supply groove 31, the outer shell 7 and the working plane plate 10 are all made of magnetic conductive materials, and are respectively used as part of the magnetic circuit formed by the air-magnetic hybrid suspension unit for micro-low gravity. The magnetic conductive material constituting the inner porous medium 2 or the outer porous medium 4 is one of porous iron, porous nickel and porous iron-nickel soft magnetic alloy. The magnetic conductive material constituting the circular plate 3 with the main air supply groove 31 or the outer shell 7 or the working plane plate 10 is a dense and non-porous magnetic conductive material. The dense and non-porous magnetic conductive material is one of industrial pure iron, iron-nickel soft magnetic alloy and silicon steel. In order to prevent the magnetic circuit from leaking out, the magnetic isolation ring 1 and the supporting column 5 are both non-magnetic conductive materials, which can be selected from one of aluminum, copper and ceramics.

[0038] like Figure 1 and Figure 2 As shown, the main air supply groove 31 and the auxiliary air supply groove 73 are both multi-stage annular grooves, and the multi-stage annular grooves are all connected to the air supply hole 75. The air supply hole 75 is connected to an air source, and the air source is generated by an air compressor, and is sequentially connected to an air storage tank, a filter and a pressure gauge through an air pipe. The compressed gas is sent into the auxiliary air supply groove 73 and the main air supply groove 31 through the air supply hole 75, and flows into the outer porous medium 4 and the inner porous medium 2 through the air path formed by the multi-stage annular grooves of the auxiliary air supply groove 73 and the main air supply groove 31. Due to the throttling effect of the porous medium, an air film is generated on the surface of the working plane of the working plane plate 10, thereby greatly reducing the direct contact between the surfaces, thereby reducing the lateral friction.

[0039] like Figure 3 As shown, the magnetic circuit formed by the air-magnetic hybrid suspension unit for micro-low gravity is: the permanent magnet 6 is placed at the rear of the main air supply groove 31, and the magnetic circuit generated by the permanent magnet 6 passes through the circular plate 3 made of magnetic conductive material with the main air supply groove 31, the inner porous medium 2 and the working plane of the working plane plate 10 in sequence, and then reaches the outer porous medium 4 and the outer shell 7 and returns to the permanent magnet 6, thereby forming a complete circuit.

[0040] Application examples of the suspension unit of the present invention are as follows: Figure 4As shown, an air supply device is used to supply air to the air-magnetic hybrid suspension unit, and the air-magnetic hybrid suspension unit is placed upside down on a working plane (the working iron plate plane in this application example) through a fixture. The magnetic circuit generated by the permanent magnet unit generates an upward suction force Fm on the working plane through a bearing shell made of a magnetic conductive material and a porous medium, which is used to absorb the gravity G of the hybrid suspension unit body and the suspended object (a folded solar panel in this application example) to provide a vertical microgravity environment. After the porous air-floating bearing is connected to an external air pump for air supply through the air supply hole, a vertical downward air-floating repulsive force Fq is generated to push the suspension unit to a suspended state. At this time, a layer of air film is formed between the upper end surface of the porous air-floating bearing and the lower surface of the magnetic air-floating workbench, realizing magnetic suction inverted suspension gas lubrication.

[0041] Another structure of the suspension unit of the present invention is to change the magnetic unit therein from a permanent magnet to an electromagnet 61 and a coil 62, such as Figure 5 As shown, the electromagnet is more controllable and can control the magnetic switch, strength and direction.

[0042] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many improvements and changes without departing from the purpose of the present invention, which are all within the protection of the present invention.

Claims

1. A gas-magnetic hybrid suspension unit for low gravity based on a magnetic porous medium, comprising a housing (7), characterized in that: The housing (7) is provided with a stepped hole along the central axis; The bottom layer of the stepped hole is a central inner groove (71), and a bearing column (5) is embedded in the central inner groove (71); A permanent magnet (6) is glued between the middle step surface (74) of the stepped hole and the outer surface of the bearing column (5); a circular plate (3) with a main air supply groove (31) is glued on the upper surface of the permanent magnet (6); an inner porous medium (2) is glued on the upper surface of the circular plate (3); and radial outer peripheral dimensions of the inner porous medium (2), the circular plate (3) and the permanent magnet (6) are consistent; A magnetic isolation ring (1) is embedded between the permanent magnet (6) and the housing (7); An auxiliary air supply groove (73) is provided on the upper step surface (72) of the stepped hole, an outer porous medium (4) is glued on the upper surface of the auxiliary air supply groove (73), and the upper surface of the magnetic isolation ring (1), the upper surface of the inner porous medium (2), the upper surface of the outer porous medium (4) and the upper surface of the outer shell (7) are in the same plane, which is covered with a working plane plate (10); The lower end surface of the housing (7) is fastened with a connecting flange (8) by means of bolts, and a lifting ring (9) is screwed into the lower end surface of the connecting flange (8); An air supply hole (75) is provided from the outside of the outer shell (7) along the radial direction of the outer shell, and passes through the auxiliary air supply groove (73), the magnetic isolation ring (1) and the main air supply groove (31) in sequence.

2. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 1, characterized in that: The inner porous medium (2), the outer porous medium (4), the circular plate (3) with the main air supply groove (31), the outer shell (7) and the working plane plate (10) are respectively used as parts of the magnetic circuit and are all made of magnetic conductive materials.

3. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 2, characterized in that: The magnetic conductive material constituting the inner porous medium (2) or the outer porous medium (4) is one of porous iron, porous nickel and porous iron-nickel soft magnetic alloy.

4. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 2, characterized in that: The magnetic conductive material constituting the circular plate (3) with the main air supply groove (31), the housing (7) or the working plane plate (10) is a dense and non-porous magnetic conductive material.

5. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 4, characterized in that: The dense, non-porous magnetic conductive material is one of industrial pure iron, iron-nickel soft magnetic alloy and silicon steel.

6. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 2, characterized in that: The magnetic circuit formed by the air-magnetic hybrid suspension unit for micro-low gravity is as follows: the permanent magnet (6) is placed at the rear of the main air supply groove (31), and the magnetic circuit generated by the permanent magnet (6) passes through the circular plate (3) made of magnetic conductive material with the main air supply groove (31), the inner porous medium (2) and the working plane of the working plane plate (10) in sequence, and then reaches the outer porous medium (4) and the outer shell (7) and returns to the permanent magnet (6), thereby forming a complete circuit.

7. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 1, characterized in that: The magnetic isolation ring (1) and the supporting column (5) are both made of non-magnetic conductive materials to prevent the magnetic circuit from leaking out.

8. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 7, characterized in that: The non-magnetic conductive material is one of aluminum, copper and ceramic.

9. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 1, characterized in that: The main air supply groove (31) and the auxiliary air supply groove (73) are both multi-stage annular grooves, and the multi-stage annular grooves are both connected to the air supply hole (75). The air supply hole (75) is connected to an air source, and the air source is generated by an air compressor and is sequentially connected to an air storage tank, a filter and a pressure gauge through an air pipe.

10. The air-magnetic hybrid suspension unit for micro-low gravity according to claim 9, characterized in that: The compressed gas is fed into the auxiliary gas supply groove (73) and the main gas supply groove (31) through the gas supply hole (75), and flows into the outer porous medium (4) and the inner porous medium (2) through the gas path formed by the multi-stage annular grooves of the auxiliary gas supply groove (73) and the main gas supply groove (31). The throttling effect of the outer porous medium (4) and the inner porous medium (2) generates an air film on the surface of the working plane of the working plane plate (10), thereby reducing the direct contact between the surfaces and further reducing the lateral friction.

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