Magnetic suspension axial driving device and molecular pump

Abstract

The utility model relates to a magnetic suspension axial drive device and molecular pump, including: electromagnet assembly, floating plate and permanent magnet assembly, the floating plate is permanent magnet, the electromagnet assembly includes coil, the permanent magnet assembly includes first permanent magnet, coil, floating plate and first permanent magnet are arranged along the axis from top to bottom in order and all be annular, and the coil, floating plate and first permanent magnet are all annular. The coil and the first permanent magnet drive the floating plate to move axially through magnetic force. According to the utility model, one electromagnet assembly and one permanent magnet assembly are matched to replace two electromagnet assemblies, and the use of the electromagnet assemblies is reduced, so that the control program is simplified, and the heat productivity and the cost are reduced.

Description

Technical Field

[0001] This utility model relates to the field of molecular pumps, and in particular to a magnetic levitation axial drive device and a molecular pump. Background Technology

[0002] In existing magnetic levitation molecular pumps, the rotor assembly needs to be suspended to reduce friction, thereby increasing rotational speed and reducing heat generation. Currently, axial suspension of the rotor assembly is achieved by placing electromagnet assemblies above and below the rotor assembly's float plate. These two electromagnet assemblies apply magnetic force to the iron-containing float plate, thus suspending the entire rotor assembly. However, the need for two electromagnets results in complex control, high cost, and significant heat generation in magnetic levitation molecular pumps. Utility Model Content

[0003] The present invention aims to solve the above problems by providing a magnetic levitation axial drive device and a molecular pump, thereby solving the aforementioned problems.

[0004] A magnetic levitation axial drive device includes: an electromagnet assembly, a float plate, and a permanent magnet assembly. The float plate is a permanent magnet. The electromagnet assembly includes a coil. The permanent magnet assembly includes a first permanent magnet. The coil, the float plate, and the first permanent magnet are arranged sequentially along an axis from top to bottom and are all circular. The coil and the first permanent magnet drive the float plate to move axially through magnetic force.

[0005] Preferably, the axial positions of the electromagnet assembly and the permanent magnet assembly are relatively fixed, and the float plate rotates relative to the electromagnet assembly and the permanent magnet assembly about the axis; the float plate and the first permanent magnet are axially magnetized.

[0006] Preferably, the electromagnet assembly further includes an electromagnet housing, a first groove is formed on the lower end face of the electromagnet housing, and a second groove is formed on the upper surface of the float plate, with the first groove and the second groove corresponding to each other.

[0007] Preferably, the electromagnet housing includes an outer housing and an inner housing, the outer housing is located outside the inner housing and is fixedly connected to the inner housing, and the coil is located between the outer housing and the inner housing and is fixedly connected to the outer housing and / or the inner housing.

[0008] Preferably, the inner shell is made of magnet steel.

[0009] Preferably, the permanent magnet assembly further includes a permanent magnet shell, the first permanent magnet is embedded inside the permanent magnet shell, and the first permanent magnet is fixedly connected to the permanent magnet shell.

[0010] Preferably, the permanent magnet assembly includes a plurality of first permanent magnets, the first permanent magnets having different radii, and all the first permanent magnets being located on the same horizontal plane and coaxial.

[0011] Preferably, the system further includes a position sensor and a controller. The position sensor is located above and / or below the float and is used to detect the axial position of the float. The position sensor is electrically connected to the controller, and the controller is electrically connected to the coil.

[0012] A molecular pump using the aforementioned magnetic levitation axial drive device further includes a main shaft, a base, a housing, a rotor, and a stator. The housing is located above the base and is fixedly connected to the base. The main shaft is located inside the base. The rotor is located between the base and the housing and is fixedly connected to the main shaft. The stator is located inside the housing and is fixedly connected to the housing.

[0013] Preferably, the float plate is fixedly connected to the main shaft, the electromagnet assembly is located inside the base and fixedly connected to the base, and the permanent magnet assembly is fixedly connected to the base.

[0014] Preferably, the system also includes a filter screen, which is fixedly installed at the air inlet at the upper end of the housing, and the base is fixedly connected to the air outlet flange.

[0015] This invention has the following advantages: it uses one electromagnet assembly and one permanent magnet assembly to replace two electromagnet assemblies, which reduces the number of electromagnet assemblies used, thereby simplifying the control program and reducing heat generation and cost. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of this utility model. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.

[0017] Figure 1 : A top view of the molecular pump;

[0018] Figure 2 Right sectional view of a molecular pump;

[0019] Figure 3 :exist Figure 2 A magnified view of a section at point B in the middle;

[0020] Figure 4 : A 3D view of a molecular pump. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and examples:

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] like Figures 1 to 3 As shown, a magnetic levitation axial drive device includes: an electromagnet assembly 1, a float 2, and a permanent magnet assembly 3. The float 2 is a permanent magnet. The electromagnet assembly 1 includes a coil 11, and the permanent magnet assembly 3 includes a first permanent magnet 31. The coil 11, the float 2, and the first permanent magnet 31 are arranged sequentially along an axis from top to bottom and are all circular. The coil 11 and the first permanent magnet 31 drive the float 2 to move axially through magnetic force.

[0026] During operation, the energized coil 11 generates an axial magnetic force. The magnetic force exerted on the float 2 by the coil 11 and the first permanent magnet 31 is the same in magnitude and opposite in direction to the gravity of the float 2, thereby suspending the float 2 between the electromagnet assembly 1 and the permanent magnet assembly 3.

[0027] Preferably, the axial positions of the electromagnet assembly 1 and the permanent magnet assembly 3 are relatively fixed, and the float 2 rotates relative to the electromagnet assembly 1 and the permanent magnet assembly 3 about its axis.

[0028] Preferably, the float plate 2 and the first permanent magnet 31 are axially magnetized.

[0029] More preferably, the magnetic poles of the lower end of the float plate 2 and the upper end of the first permanent magnet 31 are opposite, so that the first permanent magnet 31 exerts an upward magnetic force on the float plate 2, thereby reducing the magnitude of the magnetic force exerted by the coil 11 on the float plate 2, and achieving the effect of reducing the power consumption and heat generation of the coil 11.

[0030] Preferably, the electromagnet assembly 1 further includes an electromagnet housing, the lower end face of which has a first groove 14, and the upper surface of the float plate 2 has a second groove 21, with the first groove 14 and the second groove 21 corresponding to each other. A protrusion is formed between adjacent first grooves 14 and between adjacent second grooves 21; the grooves and protrusions cooperate to increase the heat dissipation area and improve heat dissipation efficiency.

[0031] Preferably, the electromagnet housing includes an outer housing 12 and an inner housing 13. The outer housing 12 is located outside the inner housing 13 and is fixedly connected to the inner housing 13. The coil 11 is located between the outer housing 12 and the inner housing 13 and is fixedly connected to the outer housing 12 and / or the inner housing 13.

[0032] Preferably, the inner shell 13 is made of magnetic steel. The inner shell 13 serves as an iron core to enhance the magnetic field strength.

[0033] Preferably, the permanent magnet assembly 3 further includes a permanent magnet shell 32, the first permanent magnet 31 is embedded inside the permanent magnet shell 32, and the first permanent magnet 31 is fixedly connected to the permanent magnet shell 32.

[0034] Preferably, the permanent magnet assembly 3 includes a plurality of first permanent magnets 31, the first permanent magnets 31 having different radii, and all the first permanent magnets 31 being located on the same horizontal plane and coaxial. The plurality of first permanent magnets 31 are used to strengthen the axial magnetic force.

[0035] Preferably, the system further includes a position sensor and a controller (not shown in the figure). The position sensor is located above and / or below the float 2 and is used to detect the axial position of the float 2. The position sensor is electrically connected to the controller, which is electrically connected to the coil 11. The position sensor changes the magnitude and direction of the current in the coil 11 based on the detected position of the float 2, thereby providing the float 2 with the magnetic force required for levitation.

[0036] like Figures 1 to 4As shown, a molecular pump using the aforementioned magnetic levitation axial drive device further includes a main shaft 4, a base 5, a housing 6, a rotor 7, and a stator 8. The housing 6 is located above and fixedly connected to the base 5. The main shaft 4 is located inside the base 5. The rotor 7 is located between the base 5 and the housing 6 and is fixedly connected to the main shaft 4. The stator 8 is located inside and fixedly connected to the housing 6. It should be noted that the molecular pump is a prior art magnetic levitation molecular pump, and some components are not shown.

[0037] Preferably, the float 2 is fixedly connected to the main shaft 4, the electromagnet assembly 1 is located inside the base 5 and fixedly connected to the base 5, and the permanent magnet assembly 3 is fixedly connected to the base 5. The magnetic force exerted on the float 2 by the coil 11 and the first permanent magnet 31 is the same in magnitude and opposite in direction to the total weight of the float, main shaft 4, rotor 7, and other components, thereby suspending the float 2 between the electromagnet assembly 1 and the permanent magnet assembly 3.

[0038] More preferably, the electromagnet assembly 1 exerts an upward attractive force on the float 2, and the permanent magnet assembly 3 exerts an upward repulsive force on the float 2.

[0039] Preferably, the system also includes a filter screen 9, which is fixedly installed at the air inlet at the upper end of the housing 6, and the base 5 is fixedly connected to the air outlet flange 51. During operation, the molecular pump draws in air from the air inlet and exhausts air from the air outlet flange 51, and the filter screen 9 is used to block impurities.

[0040] The present invention has been described above by way of example, but the present invention is not limited to the specific embodiments described above. Any modifications or variations made based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A magnetic levitation axial drive device, characterized in that, The application relates to a magnetic assembly, which comprises an electromagnet assembly (1), a floating plate (2) and a permanent magnet assembly (3), the floating plate (2) is a permanent magnet, the electromagnet assembly (1) comprises a coil (11), the permanent magnet assembly (3) comprises a first permanent magnet (31), the coil (11), the floating plate (2) and the first permanent magnet (31) are sequentially arranged along an axis from top to bottom and are all annular, the coil (11) and the first permanent magnet (31) drive the floating plate (2) to axially move through magnetic force. The axial positions of the electromagnet assembly (1) and the permanent magnet assembly (3) are relatively fixed, the floating plate (2) rotates relative to the electromagnet assembly (1) and the permanent magnet assembly (3) with the axis as the axis, and the floating plate (2) and the first permanent magnet (31) are axially magnetized.

2. A magnetic levitation axial drive apparatus according to claim 1, characterized in that: The electromagnet assembly (1) further comprises an electromagnet shell, a first recess (14) is formed on the lower end surface of the electromagnet shell, a second recess (21) is formed above the floating plate (2), and the first recess (14) and the second recess (21) correspond to each other.

3. A magnetic levitation axial drive device according to claim 1, characterized in that: The electromagnet shell comprises an outer shell (12) and an inner shell (13), the outer shell (12) is located outside the inner shell (13) and is fixedly connected with the inner shell (13), and the coil (11) is located between the outer shell (12) and the inner shell (13) and is fixedly connected with the outer shell (12) and / or the inner shell (13).

4. A magnetic levitation axial drive device according to claim 3, characterized in that: The inner shell (13) is made of magnetic steel.

5. A magnetic levitation axial drive apparatus according to claim 4, characterized in that: The permanent magnet assembly (3) further comprises a permanent magnet shell (32), the first permanent magnet (31) is embedded in the inside of the permanent magnet shell (32), and the first permanent magnet (31) is fixedly connected with the permanent magnet shell (32).

6. A magnetic levitation axial drive apparatus according to claim 1, characterized by: The permanent magnet assembly (3) comprises a plurality of first permanent magnets (31), the radii of the first permanent magnets (31) are different, the first permanent magnets (31) are located on the same horizontal plane and are coaxial.

7. A magnetic levitation axial drive apparatus according to claim 6, characterized in that: The application further comprises a position sensor and a controller, the position sensor is located above and / or below the floating plate (2), the position sensor is used for detecting the axial position of the floating plate (2), the position sensor is electrically connected with the controller, and the controller is electrically connected with the coil (11).

8. A magnetic levitation axial drive apparatus according to claim 1, characterized by: The application further comprises a main shaft (4), a base (5), a shell (6), a rotor (7) and a stator (8), the shell (6) is located above the base (5) and is fixedly connected with the base (5), the main shaft (4) is located in the inside of the base (5), the rotor (7) is located between the base (5) and the shell (6) and is fixedly connected with the main shaft (4), and the stator (8) is located in the inside of the shell (6) and is fixedly connected with the shell (6).

9. A molecular pump using the magnetic levitation axial drive device according to any one of claims 1 to 8, characterized by: The floating plate (2) is fixedly connected with the main shaft (4), the electromagnet assembly (1) is located in the inside of the base (5) and is fixedly connected with the base (5), and the permanent magnet assembly (3) is fixedly connected with the base (5).

10. A molecular pump according to claim 9, characterized in that: ​

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