Magnetic suspension molecular pump

Abstract

The invention relates to the technical field of molecular pumps, and discloses a magnetic suspension molecular pump which comprises a pump body, a bearing support is installed in the pump body, a permanent magnet bearing is assembled on the bearing support, a main shaft is connected to the permanent magnet bearing, a plurality of movable pieces are fixed to the main shaft, and a plurality of static pieces are fixed in the pump body. The magnetic suspension molecular pump supports ultrahigh-speed stable rotation of a rotor, the air exhaust efficiency is optimized by combining a rotor plate-main shaft integrated hot charging structure, the size is smaller under the same air exhaust amount, meanwhile, noise is lowered, energy consumption and heat loss are reduced, and the energy efficiency conversion rate is improved; in-situ brushing-dust collection-filtering integrated cleaning of the filter screen is achieved, the risks of mechanical abrasion, sealing failure and dust invasion caused by traditional disassembly and cleaning are avoided, the service life of equipment is prolonged, and the stability of a vacuum environment is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of molecular pump technology, and more particularly to a magnetically levitated molecular pump. Background Technology

[0002] A magnetic levitation molecular pump is a high-end vacuum device that uses magnetic levitation bearing technology to achieve non-contact levitation and high-speed rotation of the rotor. Its core function is to transport gas molecules from one end of the vacuum chamber to the other end through a high-speed rotating rotor, thereby quickly removing gas molecules from the enclosed space and making the space reach a high vacuum or ultra-high vacuum state.

[0003] A search revealed that Chinese Patent CN112943707A discloses a molecular pump protective net and a molecular pump incorporating the same. The net includes: a net body with a connecting portion suitable for installation on the pump housing; and a conical member whose bottom edge is fixedly connected to the net body. The net body surrounds the conical member, and the axis of the conical member is perpendicular to the net body. When the molecular pump is turned on and begins pumping, the gas collides with the conical member at the pump inlet, altering its flow path. This allows gas pumped from ineffective areas to flow into effective areas and enter the pump. This solution, through the collision of the conical member, directs gas from ineffective areas to effective areas that affect the pumping speed, thereby increasing the gas volume in the effective areas and reducing pumping speed loss after the protective net is installed, thus improving the pump's efficiency. However, this solution still has the following shortcomings in practical use: When the above solution is in use, dust in the air will adhere to the protective screen. However, the molecular pump does not have the function of cleaning the protective screen. It is necessary to manually remove the protective screen from the molecular pump for manual cleaning. First, frequent disassembly will accelerate the mechanical wear at the interface between the protective screen and the pump body, which may lead to a decrease in sealing performance in the long run, increase the risk of gas leakage, and affect the stability of the vacuum system. Second, during manual cleaning, dust particles may enter the pump body due to improper operation or insufficient environmental control, and adhere to precision components such as rotor blades or bearings, causing problems such as dynamic balance failure and accelerated bearing wear, shortening the equipment life and reducing pumping efficiency. Furthermore, the disassembly and installation of the protective screen requires professional personnel, which not only consumes labor costs, but also causes production interruptions due to downtime for cleaning. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing molecular pump design requires manual disassembly of the protective net to clean the dust, which leads to mechanical wear and reduced sealing performance due to frequent operation. To address this, we propose a magnetic levitation molecular pump.

[0005] To achieve the above objectives, this application adopts the following technical solution: a magnetic levitation molecular pump, including a pump body, a bearing bracket installed in the pump body, a permanent magnet bearing assembled on the bearing bracket, a main shaft connected to the permanent magnet bearing, a plurality of moving plates fixed on the main shaft, and a plurality of stationary plates fixed in the pump body; The top of the pump body is provided with an annular groove, the bottom of the pump body is fixed with a magnetic plate, and the bottom of the pump body is fixed with a heightening bracket. There is a gap between the magnetic plate and the heightening bracket. A cleaning component is provided within the gap. The cleaning component includes a mounting cover and a rotating plate. The mounting cover is magnetically attached to the magnetic plate, and the rotating plate is arranged inside the mounting cover. The side of the rotating plate is provided with bristles. The mounting cover is equipped with a dust-collecting component for absorbing dust; The mounting cover is equipped with a positioning component for controlling the position of the rotating plate.

[0006] Preferably, the cleaning assembly further includes a connecting cylinder, the inner surface of which is fixed with two opposing limiting blocks. The connecting cylinder is fixed inside the mounting cover and is made of magnetic material, allowing it to be magnetically attached to a magnetic plate. There is a gap between the outer circumferential surface of the connecting cylinder and the inner surface of the mounting cover. Both the mounting cover and the connecting cylinder have holes, and a rotating shaft is movably inserted into both holes. One end of the rotating shaft extends into the inside of the connecting cylinder, and the other end extends into the outside of the mounting cover. A rotating plate is fixed at the end of the rotating shaft located inside the connecting cylinder, and a rotating ring is rotatably mounted on the rotating plate. The rotating ring is connected to the mounting cover by a spring.

[0007] Preferably, when the mounting cover is fastened to the top of the pump body, the mounting cover is inserted into the annular groove, the connecting cylinder extends into the pump body, and when the connecting cylinder extends into the pump body, the outer circumferential surface of the connecting cylinder is in contact with the inner surface of the pump body.

[0008] Preferably, the dust collection assembly includes an annular tube, a first gear, a rotating rod, and an air suction cylinder. The annular tube is fixed inside the mounting cover and has several suction ports. The first gear is fixedly sleeved on the end of the rotating shaft located outside the mounting cover. The rotating rod is rotatably mounted on the end face of the mounting cover. A second gear is fixedly sleeved on the rotating rod and meshes with the first gear. The air suction cylinder is fixed on the end face of the mounting cover. An impeller is fixedly sleeved on the rotating rod and located inside the air suction cylinder. An air suction pipe and an exhaust pipe are connected to the air suction cylinder. The end of the air suction pipe away from the air suction cylinder is connected to the annular tube. A filter cylinder is provided on the mounting cover. The end of the exhaust pipe away from the air suction cylinder is connected to the filter cylinder. The filter cylinder has a built-in filter element and an exhaust end.

[0009] Preferably, the thickness of the first gear is greater than the thickness of the second gear, and when the first gear moves with the shaft, the first gear remains engaged with the second gear.

[0010] Preferably, the positioning component includes a vertical plate and a sleeve plate. The vertical plate is fixed to the end face of the mounting cover. The vertical plate has an opening, and a locking block is slidably disposed in the opening. The locking block has an inclined surface. The locking block and the vertical plate are connected by a tension spring. The sleeve plate is fixedly sleeved on the end of the rotating shaft located outside the mounting cover. The inclined surface of the locking block is positioned opposite the edge of the sleeve plate.

[0011] Preferably, the bottom surface of the card block is provided with rotatable ball bearings, and when the sleeve plate moves between the card block and the mounting cover, the sleeve plate contacts the ball bearings.

[0012] Preferably, a sealing ring is provided on the outer circumferential surface of the connecting cylinder, the sealing ring is hollow inside, a movable cylinder is sleeved on one end of the rotating shaft outside the mounting cover, an air bladder is provided between the movable cylinder and the rotating shaft, the air bladder is connected to the sealing ring through a pipeline, a keyway is provided on the inner surface of the movable cylinder, a spline is fixed on the rotating shaft, and the spline slides in the keyway.

[0013] Preferably, the inner surface of the movable cylinder is in contact with the outer peripheral surface of the rotating shaft.

[0014] Preferably, an outer cover is fixed to the end face of the mounting cover, and an clearance opening is provided on the outer cover. The movable cylinder passes through the clearance opening, and a pull rod is fixed to the side of the locking block. The pull rod passes through the outer cover and is slidably connected to the outer cover.

[0015] The technical effects and advantages of this invention are as follows: In this invention, the magnetic levitation bearing and the permanent magnet bearing work together to eliminate mechanical friction, support ultra-high speed and stable rotation of the rotor, and optimize the air extraction efficiency by combining the integrated hot-mounted structure of the moving plate and the main shaft. The volume is smaller under the same air extraction volume, while reducing noise, energy consumption and heat loss, and improving energy efficiency conversion rate. In this invention, the magnetic mounting cover and linkage transmission mechanism enable in-situ brushing, dust collection and filtration of the filter screen, avoiding the risks of mechanical wear, sealing failure and dust intrusion caused by traditional disassembly and cleaning, extending the equipment life and ensuring the stability of the vacuum environment; In this invention, the positioning component can automatically lock the position of the rotating plate without continuous manual pressure, simplifying the operation process. The optimized thickness of the gear set ensures transmission continuity and improves the reliability of system operation. Attached Figure Description

[0016] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional structural diagram of the present invention; Figure 3 This is a structural schematic diagram of the bearing support, main shaft, and several moving plates; Figure 4 A schematic diagram showing the structure when the mounting cover is fastened to the top of the pump body; Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure; Figure 6 for Figure 5 Enlarged view of the structure at point A; Figure 7 This is a structural diagram showing the installation of the cover and outer casing; Figure 8 A structural schematic diagram of the components mounted on the end face of the cover; Figure 9 for Figure 8 Enlarged view of the structure at point B.

[0017] Legend: 1. Pump body; 11. Bearing bracket; 12. Permanent magnet bearing; 13. Main shaft; 14. Moving plate; 15. Stationary plate; 21. Annular groove; 22. Magnetic plate; 3. Filter screen; 41. Mounting cover; 42. Connecting cylinder; 421. Limiting block; 43. Rotating shaft; 44. Rotating plate; 45. Brush bristles; 46. Rotating ring; 47. Spring; 51. Annular tube; 52. Dust suction port; 53. First gear; 54. Rotating rod; 55. Second gear; 56. Suction cylinder; 57. Impeller; 58. Suction pipe; 59. Filter cylinder; 510. Exhaust pipe; 61. Vertical plate; 62. Locking block; 63. Tension spring; 64. Ball bearing; 65. Sleeve plate; 66. Pull rod; 71. Sealing ring; 72. Moving cylinder; 73. Airbag. Detailed Implementation

[0018] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0019] Reference Figure 1As shown, the present invention provides a technical solution: a magnetic levitation molecular pump, including a pump body 1, a bearing bracket 11 installed inside the pump body 1, a permanent magnet bearing 12 mounted on the bearing bracket 11, a main shaft 13 connected to the permanent magnet bearing 12, a plurality of moving plates 14 fixed on the main shaft 13, and a plurality of stationary plates 15 fixed inside the pump body 1. When the magnetic levitation molecular pump proposed in this invention is working, the electromagnetic bearing system uses controllable electromagnetic force to precisely suspend the rotor at the center of the stator, completely eliminating mechanical contact and friction, so that the main shaft 13 can rotate stably at an extremely high speed of tens of thousands to hundreds of thousands of revolutions per minute. At this time, the moving plate 14 and the stationary plate 15 form a dynamic compression chamber. When gas molecules enter from the inlet, they are repeatedly collided with the high-speed rotating moving plate 14 and given kinetic energy. At the same time, they are compressed due to the periodic change in the volume of the compression chamber. The gas molecules gradually migrate towards the exhaust port. Since the exhaust port is connected to the back vacuum pump, its pressure is much lower than that of the inlet. The gas molecules are continuously transported to the exhaust end under the pressure difference and are finally pumped away by the back pump. In this invention, the moving plate 14 and the rotor main shaft 13 are directly heat-fitted or interference-fitted instead of a sleeve shaft structure. This not only reduces the volume of the molecular pump 1 at the same pumping capacity by optimizing the length design of the moving plate 14, but also improves the coaxiality accuracy of the moving plate 14 and the main shaft 13 and ensures that the gap of the moving plate 14 is uniform. This significantly enhances the performance stability and pumping efficiency of the pump, while achieving the comprehensive effects of reducing operating noise, simplifying the assembly process, and reducing energy consumption. In addition, the molecular pump uses a grease-lubricated bearing at the exhaust end and a maintenance-free permanent magnet bearing 12 composed of a permanent magnet and a bracket at the high vacuum end. The self-magnetic force of the permanent magnet bearing 12 is used to achieve passive levitation of the rotor main shaft 13. This eliminates the mechanical friction and maintenance requirements when the end rotates, and improves the rotor speed stability through the differentiated design of the dual bearings. This achieves multiple effects such as reducing operating noise, reducing frictional heat and energy consumption, and optimizing energy efficiency conversion, and has the advantages of energy saving and environmental protection. Reference Figure 2As shown, an annular groove 21 is provided at the top of the pump body 1, and a magnetic plate 22 is fixed at the bottom of the pump body 1. A heightening bracket is also fixed at the bottom of the pump body 1. There is a gap between the magnetic plate 22 and the heightening bracket. A cleaning assembly is provided within this gap. The cleaning assembly includes a mounting cover 41 and a rotating plate 44. The mounting cover 41 is magnetically attached to the magnetic plate 22, and the rotating plate 44 is arranged inside the mounting cover 41. Brush bristles 45 are provided on the side of the rotating plate 44. The cleaning assembly also includes a connecting cylinder 42. When the mounting cover 41 is fastened to the top of the pump body 1, the mounting cover 41 is inserted into the annular groove 21. The connecting cylinder 42 extends into the pump body 1. When the connecting cylinder 42 extends into the pump body 1, the outer circumferential surface of the connecting cylinder 42 is close to the inner surface of the pump body 1. The inner surface of the connecting cylinder 42 is fixed with two opposing limiting blocks 421. The connecting cylinder 42 is fixed inside the mounting cover 41. The connecting cylinder 42 is made of magnetic material and can be magnetically attracted to the magnetic plate 22. There is a gap between the outer circumferential surface of the connecting cylinder 42 and the inner surface of the mounting cover 41. Both the mounting cover 41 and the connecting cylinder 42 have holes. A rotating shaft 43 is movably inserted into the two holes. One end of the rotating shaft 43 extends into the inside of the connecting cylinder 42, and the other end extends into the outside of the mounting cover 41. A rotating plate 44 is fixed at the end of the rotating shaft 43 located inside the connecting cylinder 42. A rotating ring 46 is rotatably mounted on the rotating plate 44. The rotating ring 46 is connected to the mounting cover 41 by a spring 47. Reference Figure 6 and Figure 7 As shown, a sealing ring 71 is provided on the outer circumferential surface of the connecting cylinder 42. The sealing ring 71 is hollow inside. A movable cylinder 72 is sleeved on one end of the rotating shaft 43 outside the mounting cover 41. The inner surface of the movable cylinder 72 is in contact with the outer circumferential surface of the rotating shaft 43. An air bladder 73 is provided between the movable cylinder 72 and the rotating shaft 43. The air bladder 73 is connected to the sealing ring 71 through a pipe. A keyway is provided on the inner surface of the movable cylinder 72. A spline is fixed on the rotating shaft 43. The spline slides in the keyway. Reference Figure 6 and Figure 7As shown, a dust-collecting assembly is provided on the mounting cover 41 for absorbing dust. The dust-collecting assembly includes an annular tube 51, a first gear 53, a rotating rod 54, and an air suction cylinder 56. The annular tube 51 is fixed inside the mounting cover 41 and has several suction ports 52. The first gear 53 is fixedly sleeved on one end of the rotating shaft 43 located outside the mounting cover 41. The rotating rod 54 is rotatably mounted on the end face of the mounting cover 41. A second gear 55 is fixedly sleeved on the rotating rod 54, and the second gear 55 meshes with the first gear 53. The thickness of the first gear 53 is greater than the thickness of the second gear 55. When the wheel 53 moves with the rotating shaft 43, the first gear 53 remains engaged with the second gear 55. The suction cylinder 56 is fixed on the end face of the mounting cover 41. An impeller 57 is fixedly sleeved on the rotating rod 54 and is located inside the suction cylinder 56. The suction cylinder 56 is connected to a suction pipe 58 and an exhaust pipe 510. The end of the suction pipe 58 away from the suction cylinder 56 is connected to the annular pipe 51. A filter cylinder 59 is provided on the mounting cover 41. The end of the exhaust pipe 510 away from the suction cylinder 56 is connected to the filter cylinder 59. The filter cylinder 59 has a built-in filter element and an exhaust end. The filter screen 3, located at the top of the pump body 1, is used to intercept dust in the air and protect the internal structural components of the pump body 1. With the use of the pump body 1, a layer of dust will accumulate on the surface of the filter screen 3, at which point the operator can clean it. Specifically, when the pump body 1 is in normal use, the connecting cylinder 42 is magnetically attached to the magnetic plate 22, and the mounting cover 41 is located between the pump body 1 and the riser bracket, forming a... Figure 1 When cleaning the filter screen 3 is required, as shown in the diagram, the operator first fastens the mounting cover 41 onto the top of the pump body 1, causing the mounting cover 41 to snap into the annular groove 21. At this time, the connecting cylinder 42 will be inserted into the pump body 1 until the connecting cylinder 42 contacts the filter screen 3, forming a... Figure 5 In the state shown, the operator first presses down the movable cylinder 72. When the movable cylinder 72 moves, it first squeezes the air bag 73. When the air bag 73 is squeezed, the gas inside the air bag 73 can enter the interior of the sealing ring 71, causing the sealing ring 71 to inflate. The sealing ring 71 in the inflated state will apply pressure to the inner surface of the pump body 1, thereby improving the sealing performance between the connecting cylinder 42 and the pump body 1, and preparing for subsequent dust collection. When the movable cylinder 72 moves to the limit position, the movable cylinder 72 can drive the rotating shaft 43 to move. When the rotating shaft 43 moves, it drives the rotating plate 44 to move until the rotating plate 44 moves to the position of contacting the two limit blocks 421. In this state, the bristles 45 on the rotating plate 44 will contact the filter screen 3. Next, the operator rotates the movable cylinder 72, causing it to drive the rotating shaft 43 to rotate via the spline. As the shaft 43 rotates, the rotating plate 44 rotates accordingly, and the bristles 45 on it brush the filter screen 3, removing the dust adhering to it. Simultaneously, the rotation of the shaft 43 also drives the first gear 53 to rotate, which in turn drives the meshing second gear 55 to rotate, ultimately causing the rotating rod 54 to rotate. Figure 6 As shown, an impeller 57 is fitted on the rotating rod 54. The impeller 57 can perform a suction action during rotation. With the rotation of the impeller 57, several dust suction ports 52 on the annular tube 51 can extract the dust brushed off by the bristles 45, and the impeller 57 discharges the dust into the filter cartridge 59. The filter cartridge 59 has a built-in filter element that can filter the dust. The clean gas is finally discharged through the filter cartridge 59, realizing the cleaning and collection of dust on the filter screen 3. This method replaces the traditional molecular pump structure. There is no need for the staff to remove the filter screen 3 from the pump body 1 for cleaning. It is not only convenient to operate, but also avoids the risk of mechanical wear and sealing degradation caused by frequent operation, and the risk of dust entering the pump body 1 and causing damage to precision parts. It is worth noting that the thickness of the first gear 53 is greater than that of the second gear 55. When the rotating plate 44 is in a position away from the filter screen 3, the bottom end of the first gear 53 meshes with the second gear 55. When the bristles 45 touch the filter screen 3, the top end of the first gear 53 meshes with the second gear 55. That is, during the movement of the rotating plate 44, the first gear 53 and the second gear 55 always remain in a meshed state, thereby ensuring the transmission effect between the rotating shaft 43 and the rotating rod 54. Reference Figure 8 and Figure 9 As shown, a positioning component is provided on the mounting cover 41 to control the position of the rotating plate 44. The positioning component includes a vertical plate 61 and a sleeve plate 65. The vertical plate 61 is fixed on the end face of the mounting cover 41. A through opening is provided on the vertical plate 61, and a locking block 62 is slidably disposed in the through opening. The locking block 62 is provided with an inclined surface. The locking block 62 and the vertical plate 61 are connected by a tension spring 63. The sleeve plate 65 is fixedly sleeved on the end of the rotating shaft 43 located outside the mounting cover 41. The inclined surface of the locking block 62 is positioned opposite the edge of the sleeve plate 65. An outer cover is fixed on the end face of the mounting cover 41. An clearance opening is provided on the outer cover. The movable cylinder 72 passes through the clearance opening. A pull rod 66 is fixed on the side of the locking block 62. The pull rod 66 passes through the outer cover and is slidably connected to the outer cover. A rotatable ball 64 is provided on the bottom surface of the locking block 62. When the sleeve plate 65 moves between the locking block 62 and the mounting cover 41, the sleeve plate 65 contacts the ball 64. When the operator presses down the movable cylinder 72 to move the rotating shaft 43, the sleeve 65 on the rotating shaft 43 moves accordingly. During the movement, the sleeve 65 will press against the inclined surface of the locking block 62. When the inclined surface of the locking block 62 receives the pressure from the sleeve 65, the locking block 62 will move. When the sleeve 65 moves to below the locking block 62, the locking block 62 will reset under the action of the tension spring 63. At this time, the locking block 62 can provide constraint for the sleeve 65, so that the rotating plate 44 is always kept close to the filter screen 3. This design eliminates the need for the operator to constantly apply downward pressure to the movable cylinder 72 during the cleaning of the filter screen 3, which is beneficial to the actual use of the device. In addition, the locking block 62 is provided with a rotatable ball 64. When the sleeve 65 moves to the position between the mounting cover 41 and the locking block 62, the ball 64 just abuts against the rotating plate 44. The design of the ball 64 can reduce the friction between the locking block 62 and the sleeve 65, allowing the sleeve 65 to rotate smoothly.

[0020] Working principle: The working principle of this magnetic levitation molecular pump achieves efficient pumping and self-cleaning functions through the synergy of mechanical, electromagnetic, and pneumatic systems: When the pump starts, the electromagnetic bearing system uses controllable electromagnetic force to precisely levitate the rotor at the center of the stator, eliminating mechanical contact and friction, causing the main shaft 13 to drive the moving vane 14 to rotate at a high speed of tens of thousands to hundreds of thousands of revolutions per minute; the moving vane 14 and the stationary vane 15 form a dynamic compression chamber, where gas molecules gain kinetic energy through repeated collisions with the high-speed moving vane 14 and are compressed during the periodic changes in the volume of the compression chamber, ultimately being continuously transported to the exhaust end and pumped away under the pressure difference between the exhaust port and the backing vacuum pump. The moving vane 14 and the main shaft 13 adopt a direct heat-fit or interference fit structure, and the length design of the moving vane 14 is optimized to reduce the volume of the pump body 1, while improving coaxial accuracy and gap uniformity, enhancing pumping efficiency and reducing noise and energy consumption. The exhaust end uses a grease-lubricated bearing, and the high vacuum end is equipped with a permanent magnet bearing 12, which uses self-magnetic force to achieve passive levitation, further reducing friction and maintenance requirements, and improving speed stability and energy conversion efficiency. A filter screen 3 is installed at the top of the pump body 1 to intercept dust. During cleaning, the magnetic mounting cover 41 and the connecting cylinder 42 are combined to fasten the mounting cover 41 into the annular groove 21 at the top of the pump body 1. The connecting cylinder 42 extends into the pump body 1 and contacts the filter screen 3. The movable cylinder 72 is pressed down to squeeze the air bag 73, causing the sealing ring 71 to inflate and expand to enhance the sealing between the connecting cylinder 42 and the pump body 1. At the same time, the movable cylinder 72 drives the rotating shaft 43 to move through the spline, so that the bristles 45 on the rotating plate 44 contact the filter screen 3. When the movable cylinder 72 is rotated, the rotating shaft 43 drives the rotating plate 44 to rotate and brush the filter screen 3. At the same time, the meshing transmission of the first gear 53 and the second gear 55 drives the impeller 57 on the rotating rod 54 to rotate. The dust suction port 52 on the annular pipe 51 simultaneously sucks up the dust that has been brushed off and transported to the filter cylinder 59 through the impeller 57 for filtration by the filter element. Finally, clean gas is discharged. The positioning component, through the engagement of the locking block 62 and the inclined surface of the sleeve plate 65, automatically locks the position of the rotating plate 44 after the rotating shaft 43 moves into place, avoiding continuous manual pressure. The ball bearings 64 on the locking block 62 reduce friction, ensuring smooth rotation of the sleeve plate 65. This solution, through the integration of magnetic levitation technology, optimized structure of the moving plate 14, differentiated dual-bearing design, and self-cleaning system of the filter screen 3, achieves high performance, low energy consumption, easy maintenance, and environmentally friendly operation of the molecular pump.

[0021] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A magnetically levitated molecular pump, characterized in that: The pump body (1) includes a bearing bracket (11) installed inside the pump body (1), a permanent magnet bearing (12) is mounted on the bearing bracket (11), a main shaft (13) is connected to the permanent magnet bearing (12), a number of moving plates (14) are fixed on the main shaft (13), and a number of stationary plates (15) are fixed inside the pump body (1). The top of the pump body (1) is provided with an annular groove (21), the bottom of the pump body (1) is fixed with a magnetic plate (22), the bottom of the pump body (1) is fixed with a heightening bracket, there is a gap between the magnetic plate (22) and the heightening bracket, and a cleaning component is provided in the gap. The cleaning component includes a mounting cover (41) and a rotating plate (44). The mounting cover (41) is magnetically attached to the magnetic plate (22), and the rotating plate (44) is arranged inside the mounting cover (41). The side of the rotating plate (44) is provided with bristles (45). The mounting cover (41) is provided with a dust-absorbing component for absorbing dust; The mounting cover (41) is provided with a positioning component for controlling the position of the rotating plate (44).

2. The magnetically levitated molecular pump according to claim 1, characterized in that: The cleaning assembly also includes a connecting cylinder (42), on the inner surface of which are fixed two opposing limiting blocks (421). The connecting cylinder (42) is fixed inside the mounting cover (41). The connecting cylinder (42) is made of magnetic material and can be magnetically attracted to the magnetic plate (22). There is a gap between the outer circumferential surface of the connecting cylinder (42) and the inner surface of the mounting cover (41). Both the mounting cover (41) and the connecting cylinder (42) have holes. A rotating shaft (43) is movably inserted into the two holes. One end of the rotating shaft (43) extends into the inside of the connecting cylinder (42), and the other end extends into the outside of the mounting cover (41). A rotating plate (44) is fixed at the end of the rotating shaft (43) located inside the connecting cylinder (42). A rotating ring (46) is rotatably mounted on the rotating plate (44). The rotating ring (46) is connected to the mounting cover (41) by a spring (47).

3. The magnetically levitated molecular pump according to claim 2, characterized in that: When the mounting cover (41) is fastened to the top of the pump body (1), the mounting cover (41) is inserted into the annular groove (21), and the connecting cylinder (42) extends into the pump body (1). When the connecting cylinder (42) extends into the pump body (1), the outer circumferential surface of the connecting cylinder (42) is in contact with the inner surface of the pump body (1).

4. The magnetically levitated molecular pump according to claim 1, characterized in that: The dust collection assembly includes an annular tube (51), a first gear (53), a rotating rod (54), and an air suction cylinder (56). The annular tube (51) is fixed inside the mounting cover (41), and several dust suction ports (52) are provided on the annular tube (51). The first gear (53) is fixedly sleeved on one end of the rotating shaft (43) located outside the mounting cover (41). The rotating rod (54) is rotatably mounted on the end face of the mounting cover (41), and a second gear (55) is fixedly sleeved on the rotating rod (54), and the second gear (55) meshes with the first gear (53). The air suction cylinder (56) is fixedly... An impeller (57) is fixedly sleeved on the rotating rod (54) and located inside the suction cylinder (56). The suction cylinder (56) is connected to a suction pipe (58) and an exhaust pipe (510). The end of the suction pipe (58) away from the suction cylinder (56) is connected to an annular pipe (51). A filter cylinder (59) is provided on the mounting cover (41). The end of the exhaust pipe (510) away from the suction cylinder (56) is connected to the filter cylinder (59). The filter cylinder (59) has a built-in filter element and an exhaust end.

5. The magnetically levitated molecular pump according to claim 4, characterized in that: The thickness of the first gear (53) is greater than the thickness of the second gear (55). When the first gear (53) moves with the rotating shaft (43), the first gear (53) remains engaged with the second gear (55).

6. The magnetically levitated molecular pump according to claim 2, characterized in that: The positioning component includes a vertical plate (61) and a sleeve plate (65). The vertical plate (61) is fixed on the end face of the mounting cover (41). The vertical plate (61) has an opening, and a locking block (62) is slidably disposed in the opening. The locking block (62) has an inclined surface. The locking block (62) and the vertical plate (61) are connected by a tension spring (63). The sleeve plate (65) is fixedly sleeved on the end of the rotating shaft (43) located outside the mounting cover (41). The inclined surface of the locking block (62) is positioned opposite the edge of the sleeve plate (65).

7. The magnetically levitated molecular pump according to claim 8, characterized in that: The bottom surface of the card block (62) is provided with a rotatable ball (64). When the sleeve plate (65) moves between the card block (62) and the mounting cover (41), the sleeve plate (65) contacts the ball (64).

8. The magnetically levitated molecular pump according to claim 2, characterized in that: A sealing ring (71) is provided on the outer circumferential surface of the connecting cylinder (42). The sealing ring (71) is hollow inside. A movable cylinder (72) is sleeved on one end of the rotating shaft (43) outside the mounting cover (41). An air bladder (73) is provided between the movable cylinder (72) and the rotating shaft (43). The air bladder (73) is connected to the sealing ring (71) through a pipe. A keyway is provided on the inner surface of the movable cylinder (72). A spline is fixed on the rotating shaft (43). The spline slides in the keyway.

9. The magnetically levitated molecular pump according to claim 8, characterized in that: The inner surface of the movable cylinder (72) and the outer peripheral surface of the rotating shaft (43) are in contact with each other.

10. The magnetically levitated molecular pump according to claim 6, characterized in that: The end face of the mounting cover (41) is fixed with an outer cover, and an opening is provided on the outer cover. The movable cylinder (72) passes through the opening. A pull rod (66) is fixed on the side of the locking block (62). The pull rod (66) passes through the outer cover and is slidably connected to the outer cover.

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