Oil-free dry type mechanical vacuum pump

Abstract

The oil-free dry type mechanical vacuum pump comprises a cylinder body, an eccentric rotor and rotor blades capable of stretching and retracting in the radial direction, a plurality of first electromagnets are arranged in the cylinder body to form an electromagnetic array, second electromagnets or permanent magnets are embedded in the front ends of the rotor blades, and third electromagnets and fourth electromagnets are arranged at the rear ends of the rotor blades and the bottoms of rotor grooves correspondingly. On-off and polarity of each electromagnet are controlled through a control system, and magnetic force adjustment of the blade in each quadrant is achieved. Diagonal planes are arranged at the front ends of the blades, shock waves are formed in the compression process, and the exhaust efficiency is improved. The pump shell is provided with an exhaust body and a fourth quadrant one-way gulp valve used for reducing the compression ratio and preventing condensation. The system has the advantages of oil-free operation, intelligent control, overheating suppression, high-vacuum and high-stability output and the like, and is particularly suitable for industrial scenes with high cleanliness requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical engineering and fluid machinery, and in particular relates to an oil-free dry mechanical vacuum pump. Background Art

[0002] Vacuum pumps, key equipment for achieving low-pressure environments, are widely used in semiconductor manufacturing, pharmaceutical drying, biological experiments, photovoltaic packaging, food processing, and other applications requiring extremely high levels of environmental cleanliness and pumping stability. Vacuum pumps can be categorized into two types: oil-sealed and oil-free dry types, depending on their lubrication method.

[0003] In the existing technology, traditional rotary vane vacuum pumps usually adopt an oil seal lubrication structure. By injecting vacuum pump oil into the pump chamber, it can achieve a seal between the vanes and the cylinder body and reduce friction loss. However, this structure has the following prominent problems:

[0004] Prone to oil mist pollution: During operation, the pump oil is carried out along with the gas and forms oil mist, which not only pollutes the air, but may also be adsorbed in the exhaust system to form carbon deposits, seriously affecting the stability of the high-clean process and the quality of the finished product. It is especially difficult to apply in occasions with extremely high cleanliness requirements such as medicine, electronics and vacuum packaging.

[0005] Maintenance is complex and frequent: Oil-sealed pumps must have their pump oil replaced and their oil mist separators cleaned regularly. During operation, the oil is easily degraded by factors such as high temperature and mixed air, which increases maintenance cycles and operating costs.

[0006] Unstable vacuum performance and limited life: When the pump oil evaporates, oxidizes or becomes contaminated, it will affect the sealing performance and cause the ultimate vacuum degree to drop; at the same time, the wear of components caused by mechanical friction also reduces the life of the entire machine.

[0007] To address these issues, oil-free dry vacuum pumps have been developed in recent years. These utilize non-lubricating materials or structural methods to achieve sealing, eliminating the need for liquid grease, thereby improving system cleanliness and reducing maintenance requirements. Dry rotary vane pumps, due to their simple structure, compact size, and stable operation, offer advantages in the low to medium vacuum range.

[0008] However, existing dry vane pumps still have many bottlenecks in structure and control, mainly including:

[0009] The blade extension depends on centrifugal force, the control cannot be adjusted, and the rhythm of the compression zone and the separation of the segments cannot be achieved;

[0010] Gas in high-pressure areas is prone to overheating and condensation, and lacks effective thermal regulation and air supply and cooling mechanisms;

[0011] The blades and the cylinder body are in constant friction, resulting in severe wear and limited service life;

[0012] The disturbance at the outlet is strong and the shock wave is unstable, which affects the exhaust efficiency of the tail section;

[0013] The control system lacks position awareness and cannot actively adjust blade behavior based on operating status.

[0014] Therefore, there is an urgent need to propose an oil-free dry mechanical vacuum pump with innovative structure, stable operation and regional adjustment capability, which can not only completely solve the pollution problem of oil-sealed pumps, but also achieve comprehensive breakthroughs in efficient compression, thermal stability and intelligent control to meet the industrial needs under higher cleanliness and more complex working conditions. Summary of the Invention

[0015] The purpose of the present invention is: The present invention aims to provide an oil-free dry mechanical vacuum pump, which, through the organic combination of an electromagnetically controlled blade mechanism, shock wave compression assistance, an air supply and anti-condensation system, and a high-response control logic, not only breaks through the structural limitations and control lag problems of traditional dry vacuum pumps, but also achieves comprehensive improvements in ultimate vacuum capacity, thermal stability, and adaptability to moisture-resistant working conditions. It is particularly suitable for use in scenarios such as semiconductor manufacturing, precision machining, and pharmaceutical drying that have extremely high requirements for vacuum performance and cleanliness.

[0016] The technical solution adopted in the present invention is as follows:

[0017] An oil-free dry mechanical vacuum pump comprises a cylindrical pump casing, wherein a cylinder body having a circular vertical cross-section is formed within the pump casing; an air inlet is provided on one side of the upper end of the cylinder body, and an air outlet is provided on the other side; a rotor is provided inside the cylinder body, eccentrically disposed upward and toward the air outlet; the top of the rotor contacts the cylinder body; a plurality of rotor grooves are uniformly formed on the circumferential surface of the rotor radially toward the center of the circle; the rotor grooves are each paired with rotor blades; the rotor blades are radially slidable along the rotor grooves; when the rotor rotates, the rotor blades are thrown out under the action of centrifugal force and slide along the inner surface of the cylinder body, gradually compressing the air toward the air outlet;

[0018] It is characterized in that the cylinder body is evenly embedded with multiple first electromagnets from the air inlet side to the air outlet side to form an electromagnetic array; the rotor blade is embedded with a second electromagnet or a permanent magnet near the front end, and the rear end is provided with a third electromagnet; the bottom of the rotor slot is provided with a fourth electromagnet, and a control system controls the magnetic field strength and direction of each electromagnet; the first electromagnet and the second electromagnet or the permanent magnet have the same poles on the opposite surfaces that repel each other, ensuring that there is a gap between the front end of the rotor blade and the inner surface of the cylinder body during the rotation of the rotor; the third electromagnet and the fourth electromagnet have opposite poles that attract each other.

[0019] The front end of the rotor blade is provided with an oblique section, which faces the direction of the rotor rotation so that a shock wave is formed in front of it during high-speed movement, thereby preventing air from passing through the gap between the front end of the rotor blade and the inner surface of the cylinder body.

[0020] Among them, a gas row is provided on one side of the pump housing; a guide channel, a reflux chamber, an air uniformity chamber and a filter chamber are provided in the exhaust body; the guide channel is connected with the air outlet; the reflux chamber and the air uniformity chamber are respectively connected with the guide channel; the air uniformity chamber is connected with the filter chamber, and an air filter is provided at the connection point; the filter inlet of the air filter is connected with the air uniformity chamber, and the filter outlet of the air filter is located in the filter chamber; the filter chamber is provided with a final air outlet.

[0021] In which, a one-way air supply valve that can ventilate into the cylinder body is provided on the side of the pump housing; the one-way air supply valve is connected to the cylinder body and the one-way air supply valve is connected to the reflux chamber through a pipeline; the connection position of the one-way air supply valve and the cylinder body is within the fourth quadrant close to the air outlet established with the rotor as the center; the air supply valve is used to introduce part of the gas in the reflux chamber into the fourth quadrant area in the cylinder body to reduce the compression ratio of this area, thereby preventing the condensation of the high-pressure gas and water vapor mixture and discharging it before it reaches the condensation point.

[0022] Wherein, the number of the rotor blades is six.

[0023] Among them, an elastic sheet is provided at the junction of the guide channel and the air outlet; one end of the elastic sheet is fixedly provided, and the other end covers the air outlet in a static state, so that air can be exhausted outward from the air outlet.

[0024] The control system is used to calculate the linear velocity v(θ) of the front end of the rotor blade based on the real-time angular velocity ω and the angle-radius function r(θ) set by the cylinder structure. The calculation formula is:

[0025] v(θ) = ω·r(θ); where θ is the current rotor angle; ω is the rotor angular velocity; and r(θ) is the eccentric radius of the rotor blade tip at angle θ.

[0026] When v(θ)≥Vth, the control system determines that the rotor blade is in the shock wave existence area, and Vth is the preset speed threshold for the shock wave to be established;

[0027] In the shock wave existence area, the control system controls the first electromagnet to output a repulsive force F em1 (θ), so that it is combined with the centrifugal force F c (θ) satisfies the following relationship:

[0028] F em1 (θ)≈0.9·F c (θ),F c (θ)=m·ω 2 ·r(θ);

[0029] Among them F em1(θ) is the repulsive magnetic force exerted by the first electromagnet on the front end of the rotor blade at angle θ; F c (θ) is the centrifugal force on the rotor blade; m is the mass of the rotor blade;

[0030] The repulsive force is used to maintain a small gap between the front end of the rotor blade and the inner wall of the cylinder to avoid direct contact, while forming a stable shock wave during the high-speed compression process.

[0031] In which, the control system controls the first electromagnet, the third electromagnet and the fourth electromagnet to work together in the process of the angle range from the second quadrant at the air inlet to the first quadrant at the air outlet, so that the rotor blades extend and slide toward the inner wall of the cylinder under the combined action of centrifugal force and electromagnetic force, so as to complete the suction and compression process.

[0032] When the rotor blades rotate to the first quadrant of the cylinder, the control system increases the attraction of the third electromagnet and the fourth electromagnet, so that:

[0033] F em1 (θ)+F a (θ)>F c (θ); where F em1 (θ) is the repulsive magnetic force exerted by the first electromagnet on the front end of the rotor blade at angle θ; F a (θ) is the attractive magnetic force exerted by the third and fourth electromagnets on the tail of the blade; F c (θ) is the centrifugal force of the blade at angle θ;

[0034] This allows the rotor blades to overcome the centrifugal force and actively retract into the rotor slots, avoiding interference with the cylinder body in the air outlet area.

[0035] The control system uses each angle interval as the control step to periodically calculate and update: blade linear velocity v(θ); centrifugal force F c (θ); repulsive force F em1 (θ) and the attractive combination F em1 (θ)+F a (θ); realize full-cycle dynamic magnetic control regulation synchronized with the rotor rotation process.

[0036] The beneficial effects of the present invention include:

[0037] This invention introduces a number of innovative designs based on the traditional dry rotary vane vacuum pump structure, significantly improving the overall pumping performance, thermal stability, airflow control capability, and system reliability of the whole machine. It has the following comprehensive technical advantages:

[0038] First, in terms of the compression mechanism, the present invention innovatively evenly distributes electromagnetic arrays in the second to fourth quadrants of the cylinder, and provides magnetic elements with directional control functions at the front and rear ends of the rotor blades. The control system uses real-time adjustment of the magnetic field strength and polarity in each area to ensure that the rotor blades can slide stably along the inner wall of the cylinder and maintain a non-contact gap during the compression phase. This structure avoids mechanical friction while maintaining efficient sealing, allowing the gas to be gradually compressed to the outlet after entering, effectively improving the ultimate vacuum capacity. Tests have shown that this solution can achieve an ultimate vacuum of 0.45Pa, an increase of approximately 65% ​​over traditional solutions.

[0039] Secondly, to mitigate gas overheating and condensation caused by excessive compression ratios during compression, the inventors cleverly installed a one-way air supply valve in the fourth quadrant of the cylinder, connected to the reflux chamber. This valve introduces some intermediate-pressure reflux gas just before the rotor blades enter the high-pressure zone, reducing the instantaneous compression ratio, significantly slowing the temperature rise in the compression zone and minimizing the risk of condensation. Combined with the use of high-temperature magnetic-resistant materials, this solution maintains excellent compression stability and magnetic retention even in hot and humid environments.

[0040] Regarding compression path control, the present invention introduces a chamfered surface at the front end of the rotor blade, tilted in the direction of rotation. This structure creates a localized shock wave in the compression region between the third and first quadrants, effectively suppressing gas backflow and enhancing compression strength in the rear section. Acoustic array measurements have shown a nearly 22% reduction in shock wave disturbance intensity, validating the stability and enhanced effectiveness of this auxiliary compression mechanism, making it particularly suitable for the continuous exhaust of high-concentration water vapor mixtures.

[0041] In terms of control system design, this invention utilizes a coordinated speed and angular position control algorithm to synchronize the on / off and polarity switching of the electromagnets within each quadrant, precisely matching the blade's dynamic "expansion-compression-retraction" rhythm. When the blade enters the first quadrant near the outlet, the system actively draws the blade back into the rotor slot to avoid interference with the outlet edge structure and ensure continuous exhaust. In the second through fourth quadrants, the blade is compressed against the wall, ensuring continuous shock wave formation. The control response time is as low as 16ms, significantly outperforming traditional solutions and demonstrating strong system connectivity and dynamic adaptability.

[0042] Furthermore, all materials used in the invention have been optimized for magnetic compatibility. The pump and cylinder bodies are constructed of non-magnetic alloys, the rotor slot bottom features a flux-guiding structure, and the electromagnet flux is centralized. This ensures a stable electromagnetic field distribution and prevents magnetic drift or response failure caused by material interference in high-temperature environments. Long-term test data shows that after six hours of continuous operation, the magnetic response stability remains above 97%, and the remanence exceeds 91%, further verifying the reliability and engineering practicality of the entire system.

[0043] In summary, the present invention organically combines the electromagnetically controlled blade mechanism, shock wave compression assistance, air replenishment and anti-condensation system with high-response control logic, which not only breaks through the structural limitations and control lag problems of traditional dry vacuum pumps, but also achieves comprehensive improvements in ultimate vacuum capacity, thermal stability, and adaptability to moisture-resistant working conditions. It is particularly suitable for use in scenarios such as semiconductor manufacturing, precision machining, and pharmaceutical drying that have extremely high requirements for vacuum performance and cleanliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a schematic cross-sectional view of a vacuum pump of the present invention;

[0045] Figure 2 This is a schematic diagram of the present invention dividing quadrants with the cylinder as the center;

[0046] Figure 3 A partial schematic diagram of the present invention including rotor blades;

[0047] Figure 4 It is a partial schematic diagram of the present invention including an air-disturbing structure;

[0048] Figure 5 This is a flow chart of the motion process of the vacuum pump within one rotation of the rotor of the present invention.

[0049] In the figure, 1. pump casing; 11. air supply valve; 12. pipeline; 2. cylinder body; 21. air inlet; 22. air outlet; 23. first electromagnet; 3. rotor; 4. rotor slot; 41. fourth electromagnet; 5. rotor blade; 51. second electromagnet; 52. third electromagnet; 53. bevel; 6. exhaust gas; 61. flow guide; 62. reflux chamber; 63. air uniformity chamber; 64. filter chamber; 65. air filter; 66. final air outlet; 67. elastic sheet; 71. air disturbance chamber; 72. high-frequency ultrasonic vibration head; 73. spoiler; 731. head; 732. left wing; 733. right wing; 734. elastic telescopic rod; 735. roller. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] See also Figures 1 to 4This embodiment discloses an oil-free dry mechanical vacuum pump comprising a cylindrical pump housing 1, within which is housed a cylinder body 2 having a circular vertical cross-section. An eccentrically arranged rotor 3 is housed within the cylinder body 2. The top of the rotor 3 contacts the inner wall of the cylinder body 2, and its circumference is radially defined by multiple rotor slots 4. Each rotor slot 4 houses a slidable rotor blade 5. In this embodiment, there are six blades. As the rotor 3 rotates, the blades 5 extend under the action of centrifugal force and cooperate with the inner wall of the cylinder body 2 to form multiple air chambers. This gradually compresses air from the air inlet 21 to the air outlet 22, achieving vacuum.

[0052] The cylinder 2 is arranged as follows: an air inlet 21 is located in the upper second quadrant, an air outlet 22 is located in the upper right first quadrant, and an air supply valve 11 is embedded in the lower right fourth quadrant. To achieve contactless compression and dynamic air gap control, a magnetron array is formed by evenly spaced first electromagnets 23 along the inner wall of the cylinder 2, extending from the air inlet 21 to the air outlet 22. A second electromagnet 51 or permanent magnet is embedded at the front end of the rotor blade 5, and a third electromagnet 52 is located at the rear end. A fourth electromagnet 41 is located at the bottom of the rotor slot 4. A control system controls the direction and strength of the magnetic field of each of these electromagnets, coordinating repulsion, attraction, or static action according to the real-time angle θ.

[0053] In order to prevent condensation of water vapor in the compression area, a one-way air supply valve 11 is provided in the fourth quadrant of the cylinder body 2. The valve is connected to the reflux chamber 62 in the exhaust system through a pipe 12, which can inject some uncondensed but pressurized gas back into the early compression stage (fourth quadrant) to appropriately reduce the compression ratio and inhibit water vapor from reaching the condensation point, thereby improving the anti-condensation ability and ensuring the long-term stable operation of the pump body.

[0054] To improve compression efficiency and sealing, the rotor blades 5 are equipped with a chamfered surface 53 at their front ends, oriented in the direction of rotor rotation. This creates an oblique front shock wave in the compression chamber. When the rotational speed is high enough and the blade linear velocity meets the shock wave conditions, a localized shock wave forms at the leading edge of the chamfered surface, effectively preventing gas from leaking through the gap at the blade tip and enhancing compression sealing.

[0055] The exhaust structure is located on the side of the pump housing 1 and includes a flow channel 61, a reflux chamber 62, an air distribution chamber 63, and a filter chamber 64. Air flows through the flow channel, the air distribution chamber, and the filter chamber in sequence, and is ultimately discharged through an air outlet 66. An air filter 65 is located between the filter chamber and the air distribution chamber to ensure clean exhaust.

[0056] An elastic sheet 67 is provided between the guide channel 61 and the air outlet 22 , the free end of which covers the air outlet and is pushed open under negative pressure or gas impact, thereby realizing integrated oil-free exhaust.

[0057] To ensure the functional stability and control accuracy of the electromagnetic action mechanism during high-speed and long-term operation, the following material and structural optimization measures are adopted in this embodiment:

[0058] The pump housing 1 and the cylinder body 2 are made of non-magnetic materials, such as aluminum alloy (6061-T6) or austenitic stainless steel (304), which have good mechanical strength and heat resistance and will not interfere with the magnetic field distribution; the rotor 3 body is also made of non-magnetic aluminum alloy, and a soft magnetic alloy block (such as Permalloy) is partially embedded in the bottom area of ​​the slot to guide the magnetic field and avoid magnetic distortion caused by overall magnetic conductivity.

[0059] The rotor blades 5 are made of high-performance PEEK polymer or ceramic materials, with high-temperature, demagnetization-resistant NdFeB permanent magnets (rated above 200°C) or micro-controllable electromagnetic components embedded at the front and rear ends of the blades. These magnetic components are secured to the rotor body with an insulating coating to prevent demagnetization and displacement in hot conditions.

[0060] In order to focus the magnetic flux and prevent the magnetic field from spreading to the non-controlled area, a flux directional focusing ring is set on the back of each first electromagnet 23. The focusing ring can be a μ alloy disc or a ferrite sleeve, which can effectively improve the magnetic field strength and directionality; the electromagnet part is wound with H-class heat-resistant enameled copper wire, and the magnetic core is made of silicon steel sheet laminated or low eddy current soft magnetic material, and is equipped with a thermal isolation shell to ensure that it maintains a stable magnetic response during continuous operation.

[0061] With the above materials and structures, the control system can accurately control the extension and retraction of the rotor blades in different quadrants, specifically:

[0062] In the second to fourth quadrants, the front end of the blade is continuously repelled by the first electromagnet to form wall compression, maintaining the effective shock wave area;

[0063] In the front section of the first quadrant, the blades are quickly retracted by electromagnetic attraction to avoid interference with the air outlet 22;

[0064] In the second quadrant, the rotor blade 5 pops out from the retracted state. However, since the first quadrant is connected to the air inlet 21 and has a large clearance space, the rotor blade 5 will not hit the cylinder body 2 even if it pops out quickly to the limit. Therefore, it only needs to be decelerated by the attraction of the third electromagnet 52 and the fourth electromagnet 41.

[0065] The air supply valve 11 takes effect in the fourth quadrant, introducing the gas in the reflux chamber 62 into the cylinder 2, reducing the compression ratio and preventing water vapor condensation;

[0066] This embodiment ensures that the magnetically controlled oil-free dry vacuum pump has stable and controllable operating capabilities under high performance, high frequency response, and high humidity conditions through systematic design of materials and structures.

[0067] Furthermore, the control system is used to calculate the linear velocity v(θ) of the front end of the rotor blade 5 based on the real-time angular velocity ω and the angle-radius function r(θ) set by the cylinder 2 structure. The calculation formula is:

[0068] v(θ)=ω·r(θ); where θ is the current rotor angle; ω is the angular velocity of the rotor; and r(θ) is the eccentric radius of the front end of the rotor blade 5 at the angle θ.

[0069] When v(θ)≥Vth, the control system determines that the rotor blade is in the shock wave existence area, and Vth is the preset speed threshold for the shock wave to be established;

[0070] In the shock wave existence area, the control system controls the first electromagnet 23 to output a repulsive force F em1 (θ), so that it is combined with the centrifugal force F c (θ) satisfies the following relationship:

[0071] F em1 (θ)≈0.9·F c (θ),F c (θ)=m·ω 2 ·r(θ);

[0072] Among them F em1 (θ) is the repulsive magnetic force exerted by the first electromagnet on the front end of the rotor blade 5 at angle θ; F c (θ) is the centrifugal force on the rotor blade 5; m is the mass of the rotor blade;

[0073] The repulsive force is used to maintain a small gap between the front end of the rotor blade and the inner wall of the cylinder to avoid direct contact, while forming a stable shock wave during the high-speed compression process.

[0074] Furthermore, when the rotor blade 5 rotates to the first quadrant of the cylinder 2, the control system increases the attraction force between the third electromagnet 52 and the fourth electromagnet 41, so that:

[0075] F em1 (θ)+F a (θ)>F c (θ); where F em1 (θ) is the repulsive magnetic force exerted by the first electromagnet on the front end of the rotor blade 5 at angle θ; F a (θ) is the attractive magnetic force exerted by the third and fourth electromagnets on the tail of the blade; F c (θ) is the centrifugal force of the blade at angle θ;

[0076] As a result, the rotor blades overcome the centrifugal force and actively retract into the rotor slots 4 to avoid interference with the cylinder body 2 in the area of ​​the air outlet 22 .

[0077] Furthermore, the control system uses each angle interval as a control step to periodically calculate and update: blade linear velocity v(θ); centrifugal force F c (θ); repulsive force F em1 (θ) and the attractive combination F em1 (θ)+F a (θ); realize full-cycle dynamic magnetic control regulation synchronized with the rotor rotation process.

[0078] See also Figure 5 , the motion process of the vacuum pump during one rotation of the rotor 3 is:

[0079] Phase 1: Inhalation (second quadrant, 0° to 90°)

[0080] When the rotor 3 rotates to the second quadrant (corresponding to an angle of 0° to 90°), the vacuum pump is in the suction process. At this time, the air inlet 21 provided on the cylinder body 2 begins to draw air into the air chamber enclosed by two adjacent rotor blades 5 and the inner wall of the cylinder body.

[0081] During this process, centrifugal force forces the blade 5 out of the rotor slot 4, slowing it down via the third and fourth electromagnets 52 and 41. As it rotates, it slides against the inner wall of the cylinder, forming a closed, mobile suction chamber. To prevent wear and tear between the blade tip and the cylinder wall, the control system at this stage instructs the first electromagnet 23 embedded in the cylinder to apply a slight repulsive force to the second electromagnet 51 embedded at the blade's tip, forcing the blade to adhere to the wall while maintaining a slight gap.

[0082] Because compression has not yet begun at this stage and the gap is large, the conditions for shock wave generation are not met. The control system sets this stage as a "shock-wave-free suction phase," maintaining only stable repulsion to prevent interference with subsequent compression. During this phase, the control system continuously monitors angular velocity (ω) and angular position (θ) to prepare data input for the next compression phase.

[0083] The second stage: initial compression and air replenishment (third quadrant, 90°~180°)

[0084] As the rotor continues to rotate into the third quadrant (90° to 180°), the volume of the enclosed air chamber where rotor blade 5 is located begins to decrease, and the compression process begins. The blade continues to rotate downward and right along with the rotor, and the originally inhaled gas is gradually compressed.

[0085] At this stage, shock wave conditions begin to appear. If the linear velocity reaches or exceeds the shock wave threshold, the beveled surface 53 at the front end of the blade will form a primary shock wave structure, preventing air from leaking through the front end gap, thereby improving sealing and compression efficiency.

[0086] At the same time, to prevent water vapor condensation caused by an excessively high compression ratio, a one-way air supply valve 11 in the fourth quadrant of the cylinder introduces an appropriate amount of high-temperature gas from the exhaust system's return chamber 62. The control system determines whether air supply is necessary based on the current pressure trend, and the air supply action point is controlled in the early part of the fourth quadrant (5° to 10° before 180°). This air supply reduces the compression ratio, delays the condensation point, and implements dry compression anti-condensation.

[0087] The third stage: strong compression and shock wave maintenance stage (fourth quadrant, 180°~270°)

[0088] When the rotor rotates to the fourth quadrant (180° to 270°), the previously shrinking air chamber reaches its minimum volume, compression reaches its peak, and gas pressure rises rapidly. The linear velocity of the rotor blades reaches its peak during this phase, and the front beveled surface 53 forms a stable, continuous, and strong shock wave in the airflow. The air supply function terminates during this phase to prevent interference with shock wave formation. The system defines this phase as the "shock wave maintenance and high-pressure compression phase."

[0089] Stage 4: Blade retraction and exhaust (first quadrant, 270° to 360°)

[0090] When the rotor rotates to the first quadrant (270° to 360°), the compressed air is pushed to the vicinity of the air outlet 22 at the upper end of the cylinder. In this area, the rotor blades, which were originally moving at high speed, need to quickly retract into the rotor slots before passing through the air outlet to avoid collision or interference with the air outlet.

[0091] The compressed air enters the flow channel 61 through the air outlet 22, passes through the reflux chamber 62, the air homogenizing chamber 63 and the filter chamber 64, and is finally discharged from the air outlet 66. An elastic sheet 67 is provided on the exhaust path, which is lifted by the air pressure to help reduce vibration and noise and regulate airflow.

[0092] After this phase is completed, the rotor enters the next intake phase and the cycle repeats.

[0093] This embodiment also provides an air disturbance structure. The cylinder body 2 is provided with an air disturbance chamber 71 at the air outlet 22. The air disturbance chamber is provided with a high-frequency ultrasonic vibrating head 72 and a "human"-shaped spoiler 73. The spoiler 73 includes a head 731, an S-shaped left wing 732, and an inwardly concave arc-shaped right wing 733. The head is connected to the inner wall of the pump casing via a torsion spring to provide an initial preload consistent with the direction of rotor rotation. The right wing is connected to an elastic telescopic rod 734, the front end of which is a roller 735. This produces periodic rolling disturbances on the curved surface of the right wing in accordance with the flow rhythm, and in conjunction with the ultrasonic disturbance, enhances the directional stability of the gas drive and the uniformity of the discharge.

[0094] The spoiler 73 adopts an asymmetric "human" shaped structure, including a head 731, an S-shaped left wing 732 and an inward-concave arc-shaped right wing 733. This design is not a traditional simple curved plate, but is obtained by multi-segment variable curvature modeling and optimization based on the velocity distribution and turbulence induction characteristics of the gas flowing from the high-pressure chamber to the outlet. The head 731 is installed on the inner wall of the pump casing through a torsion spring, so that the spoiler has an initial deflection angle consistent with the direction of rotation of the rotor, providing a pre-tightening force to maintain the formation of a deflection guide when the airflow first enters the spoiler cavity. Under the action of this deflection angle, the intake air is first guided to the area where the left wing 732 is located. The S-shaped left wing structure causes the upper high-speed airflow to generate shear disturbances in its boundary layer, breaking the laminar structure, enhancing the mixing of the airflow, stimulating the energy interaction between the main airflow and the backflow, and reducing the back pressure peak.

[0095] Roller 735, positioned at the tip of the right wing, is influenced by the exhaust rhythm and instantaneous flow velocity fluctuations, adaptively adhering to and rolling along the curved surface of the right wing under the shear force of the airflow. Elastic telescopic rods 734 provide flexible axial displacement and self-recovery capabilities, allowing the disturbance frequency and rolling amplitude to be dynamically adjusted with the exhaust rhythm. This enables self-coupling of the flow with the disturbance rhythm without the need for external sensors, effectively suppressing localized backflow, condensation, and tail vortex accumulation.

[0096] Furthermore, a high-frequency ultrasonic vibrator 72, operating at a frequency of ≥20 kHz, is positioned above the air disturbance chamber 71. This produces micro-amplitude high-frequency oscillations and acoustic disturbances during the exhaust process, inducing cavitation and micromolecular dispersion, enhancing gas molecular layer separation and energy decoupling, and effectively breaking up residual microclusters and condensation nuclei. This ultrasonic excitation spatially overlaps with the structural disturbance of the spoiler and functionally complements it, forming a three-dimensional, multi-scale flow disturbance field.

[0097] Two symmetrical reverse disturbance grooves are formed between the spoiler and the upper and lower walls. The initial angle is set by the head torsion spring, the left wing guide excites disturbance, and the right wing roller provides dynamic feedback, forming a closed-loop system of spoiler-guidance-rolling-stability. Ultrasonic excitation enhances the disturbance effect and prolongs the duration of disturbance in this closed-loop structure, achieving spatial resonant coverage and energy synergy between structural disturbance and acoustic disturbance.

[0098] The organic synergistic effect of this air-disturbing structure is mainly reflected in the following aspects:

[0099] The three-stage disturbance sequence forms a multi-layer pressure stabilization belt: left wing disturbance + right wing rolling + acoustic vibration jointly construct the disturbance layering to prevent the failure of a single spoiler under high-speed airflow.

[0100] The coupling of flow, structure and acoustic field improves the dispersion efficiency: as shown in the figure, the airflow is uniform without vortex or accumulation, and is quickly dispersed in the middle section of the structure.

[0101] The adaptive feedback roller + elastic telescopic rod system can adjust the disturbance frequency as the flow rate changes, achieve "beat matching", and ensure dynamic exhaust stability.

[0102] The following is a table showing comparative test data of the "Solution of the Invention" and the "Existing Technology Solution" under multiple key indicators:

[0103]

[0104] Test result analysis and conclusion:

[0105] The ultimate vacuum degree is significantly improved: The present invention relies on the fine control of magnetically controlled blades and the assistance of shock wave compression to reduce the ultimate vacuum degree of the system to 0.45Pa, which is about 1 / 3 of the existing solutions and is suitable for vacuum application scenarios with higher requirements.

[0106] Higher pumping rate: Thanks to the contactless sliding of the rotor blades and the gap control strategy, this solution improves the exhaust efficiency of a single cycle, and the 20-second pumping performance is 23% higher than that of the traditional solution.

[0107] Better temperature control in the compression zone: The fourth quadrant air supply control reduces overheating caused by excessive gas compression, with a temperature rise of only 115°C, effectively reducing the risk of water vapor condensation.

[0108] The magnetic response stability is greatly improved: the electromagnetic array and flux focusing ring improve the control accuracy, and the 6-hour operation deviation is controlled within ±2.2%, which is far better than traditional solutions.

[0109] Shock wave compression is more precise and stable: Three-dimensional acoustic array testing shows that the interference intensity in the shock wave area is smaller (61.2dB vs. 78.3dB), indicating that the compression process is smoother and more stable, especially friendly to the treatment of particles and moisture.

[0110] Enhanced exhaust capacity under wet conditions: In a high humidity environment (80% RH), this solution relies on the fourth quadrant air supply to effectively delay gas condensation, and exhausts 94.6% of moisture before reaching the condensation point, which is significantly better than traditional technology (67.2%).

[0111] In summary, the present invention is superior to existing technologies in multiple core performance indicators, especially in vacuum performance, stability and moisture resistance, showing extremely strong engineering advantages, verifying the synergistic effect and creative value of the magnetron electromagnetic array + shock wave assisted compression + four-quadrant gas replenishment mechanism.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oil-free dry mechanical vacuum pump, comprising a cylindrical pump housing (1), wherein a cylinder body (2) having a circular vertical cross-section is formed in the pump housing (1); an air inlet (21) is provided on one side of the upper end of the cylinder body (2), and an air outlet (22) is provided on the other side; a rotor (3) is eccentrically provided upward and toward the air outlet (22) in the cylinder body (2); the top of the rotor (3) contacts the cylinder body (2); a plurality of rotor grooves (4) are uniformly provided on the circumferential surface of the rotor (3) radially toward the center of the circle; the rotor grooves (4) are respectively paired with rotor blades (5); the rotor blades (5) can slide radially along the rotor grooves (4); when the rotor (3) rotates, under the action of centrifugal force, the rotor blades (5) are thrown out and slide along the inner surface of the cylinder body (2), gradually compressing air toward the air outlet (22); Its characteristics are: The cylinder (2) is evenly embedded with a plurality of first electromagnets (23) from one side of the air inlet (21) to one side of the air outlet (22) to form an electromagnetic array; a second electromagnet (51) or a permanent magnet is embedded near the front end of the rotor blade (5), and a third electromagnet (52) is provided at the rear end; a fourth electromagnet (41) is provided at the bottom of the rotor slot (4), and a control system controls the magnetic field strength and direction of each electromagnet; the first electromagnet (23) and the second electromagnet (51) or the permanent magnet have the same polarity on the opposite surfaces and repel each other, ensuring that there is a gap between the front end of the rotor blade (5) and the inner surface of the cylinder (2) during the rotation of the rotor (3); the third electromagnet (52) and the fourth electromagnet (41) have opposite polarities and attract each other.

2. The oil-free dry mechanical vacuum pump according to claim 1, characterized in that: The front end of the rotor blade (5) is provided with an oblique cut surface (53); the oblique cut surface (53) faces the rotation direction of the rotor (3) so that a shock wave is formed in front of the rotor blade (5) during high-speed movement, thereby preventing air from passing through the gap between the front end of the rotor blade (5) and the inner surface of the cylinder body (2).

3. The oil-free dry mechanical vacuum pump according to claim 1, characterized in that: A gas exhaust (6) is provided on one side of the pump housing (1); a flow guide (61), a reflux chamber (62), an air uniforming chamber (63) and a filter chamber (64) are provided in the gas exhaust (6); the flow guide (61) is communicated with the gas outlet (22); the reflux chamber (62) and the air uniforming chamber (63) are respectively communicated with the flow guide (61); the air uniforming chamber (63) is communicated with the filter chamber (64), and an air filter (65) is provided at the communication point; the filter inlet of the air filter (65) is connected to the air uniforming chamber (63), and the filter outlet of the air filter (65) is located in the filter chamber (64); and a final gas outlet (66) is provided on the filter chamber (64).

4. The oil-free dry mechanical vacuum pump according to claim 1, characterized in that: A one-way air supply valve (11) capable of ventilating the cylinder body (2) is provided on the side of the pump housing (1); the one-way air supply valve (11) is connected to the cylinder body (2) and is connected to the reflux chamber (62) through a pipe (12); the communication position between the one-way air supply valve (11) and the cylinder body (2) is within the fourth quadrant close to the air outlet (22) established with the rotor (3) as the center; the air supply valve (11) is used to introduce part of the gas in the reflux chamber (62) into the fourth quadrant area in the cylinder body (2) to reduce the compression ratio of the area, thereby preventing the high-pressure gas and water vapor mixture from condensing and discharging it before it reaches the condensation point.

5. The oil-free dry mechanical vacuum pump according to claim 1, characterized in that: The number of the rotor blades (5) is six.

6. The oil-free dry mechanical vacuum pump according to claim 1, characterized in that: An elastic sheet (67) is provided at the junction of the flow guide (61) and the air outlet (22); one end of the elastic sheet (67) is fixedly provided, and the other end covers the air outlet (22) in a static state, so that air can be exhausted outward from the air outlet (22).

7. The oil-free dry mechanical vacuum pump according to claim 2, characterized in that: The control system is used to calculate the linear velocity v(θ) of the front end of the rotor blade (5) based on the real-time angular velocity ω and the angle-radius function r(θ) set by the cylinder (2) structure. The calculation formula is: v(θ)=ω·r(θ); wherein θ is the current rotor angle; ω is the angular velocity of the rotor; and r(θ) is the eccentric radius of the front end of the rotor blade (5) at the angle θ. When v(θ)≥Vth, the control system determines that the rotor blade is in the shock wave existence area, and Vth is the preset speed threshold for the shock wave to be established; In the shock wave existence area, the control system controls the first electromagnet (23) to output a repulsive force F em1 (θ), so that it and the centrifugal force F c (θ) satisfies the following relationship: F em1 (θ)≈0.9 F c (θ),F c (θ)=m·ω 2 ·r(θ); Among them F em1 (θ) is the repulsive magnetic force exerted by the first electromagnet on the front end of the rotor blade (5) at the angle θ; F c (θ) is the centrifugal force on the rotor blade (5); m is the mass of the rotor blade; The repulsive force is used to maintain a small gap between the front end of the rotor blade and the inner wall of the cylinder to avoid direct contact, while forming a stable shock wave during the high-speed compression process.

8. The oil-free dry mechanical vacuum pump according to claim 7, characterized in that: The control system controls the first electromagnet (23), the third electromagnet (52) and the fourth electromagnet (41) to work together in the process of the angle range from the second quadrant at the air inlet to the first quadrant at the air outlet, so that the rotor blades (5) extend and slide toward the inner wall of the cylinder (2) under the combined action of centrifugal force and electromagnetic force, thereby completing the suction and compression process.

9. The oil-free dry mechanical vacuum pump according to claim 8, characterized in that: When the rotor blade (5) rotates to the first quadrant of the cylinder (2), the control system increases the attraction force of the third electromagnet (52) and the fourth electromagnet (41), so that: F em1 (θ)+F a (θ)>F c (θ); where F em1 (θ) is the repulsive magnetic force exerted by the first electromagnet on the front end of the rotor blade (5) at the angle θ; F a (θ) is the attractive magnetic force exerted by the third and fourth electromagnets on the tail of the blade; F c (θ) is the centrifugal force of the blade at angle θ; Thus, the rotor blades overcome the centrifugal force and actively retract into the rotor slot (4), avoiding interference with the cylinder body (2) in the area of ​​the air outlet (22).

10. The oil-free dry mechanical vacuum pump according to claim 9, characterized in that: The control system uses each angular interval as the control step to periodically calculate and update: blade linear velocity v(θ); centrifugal force F c (θ); repulsive force F em1 (θ) and the attractive combination F em1 (θ)+F a (θ); realize full-cycle dynamic magnetic control regulation synchronized with the rotor rotation process.

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