Vacuum pump aerodynamic thrust device and vacuum pump
By using a vacuum pump pneumatic thrust device to apply axial preload to the rotor shaft with constant gas pressure, the problem of unstable preload of the disc spring is solved, the operational stability and lifespan of the vacuum pump are improved, and the risk of equipment failure is reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING TONGJIA HONGRUI TECHNOLOGY CO LTD
- Filing Date
- 2025-08-14
- Publication Date
- 2026-08-04
AI Technical Summary
In existing vacuum pumps, the axial positioning of the rotor shaft relies on the elastic force of the disc spring, which results in unstable axial force, leading to problems such as bearing wear, noise, vibration, and equipment instability, especially under high-speed conditions.
A vacuum pump pneumatic thrust device is adopted, which drives the thrust unit to move along the rotor axis through constant gas pressure, and applies axial preload to the deep groove ball bearing to replace the traditional spring constraint, thereby achieving precise positioning of the rotor shaft.
It improves the operational stability and lifespan of vacuum pumps, avoids problems such as insufficient or excessive axial preload caused by increased bearing clearance, and reduces processing costs and equipment failure risks.
Smart Images
Figure CN224592298U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vacuum pump technology, and more specifically, to a vacuum pump pneumatic thrust device and a vacuum pump. Background Technology
[0002] In dry vacuum pumps, the axial positioning of the rotor shaft is typically achieved through the elastic force generated by a disc spring. Specifically, the disc spring, after compression and deformation, generates an axial preload. This force acts on the outer ring end face of the deep groove ball bearing, causing the outer ring to drive the balls to press against the inner ring. Because the bearing inner ring and rotor shaft are fixed with an interference fit, the axial clearance of the bearing is compressed and eliminated, thereby achieving stable fixation of the rotor's axial position.
[0003] However, this structure has certain technical defects in practical applications. First, since the rotor shaft assembly consists of multiple parts, the manufacturing tolerances of its axial dimensions accumulate step by step, thus affecting the compression of the disc spring. When the compression is too large, the axial force generated by the disc spring is excessive, causing the axial load borne by the deep groove ball bearing to exceed the reasonable range; conversely, when the compression is too small, the axial preload is insufficient and cannot effectively counteract the axial force generated by gas pressure during operation, leading to axial movement of the rotor shaft. Furthermore, during long-term operation of the vacuum pump, the axial clearance of the deep groove ball bearing gradually increases due to wear, thermal expansion, and other factors. This reduces the effective compression of the disc spring, thereby lowering the preload it provides and further exacerbating the problem of rotor axial instability.
[0004] When the axial force on the bearing is too large, especially under high-speed conditions, it can easily cause the bearing to overheat, damage to the raceway and ball surfaces, reduce the bearing's service life, and may lead to a decrease in the radial and axial positioning accuracy of the rotor shaft. Ultimately, this can cause mechanical friction between the rotor and stator, resulting in serious consequences such as increased noise, enhanced vibration, or even equipment shutdown.
[0005] Conversely, when the bearing preload is insufficient, the axial force generated by the compressed gas may exceed the axial constraint force of the bearing, causing axial displacement of the rotor shaft during operation. This can also cause collisions or friction between the rotor and stator, leading to problems such as noise, abnormal vibration, and unstable equipment operation.
[0006] In summary, the existing method of using disc springs to axially preload deep groove ball bearings has significant limitations in addressing the cumulative dimensional errors of multiple components and the clearance variations caused by long-term operation. It also makes it difficult to achieve stable control of the axial stress state of the rotor shaft, thus affecting the overall operating performance and reliability of the vacuum pump. Therefore, there is an urgent need to propose a more stable and controllable axial preload structure or adjustment method to solve the above problems. Utility Model Content
[0007] This application provides at least one pneumatic thrust device for a vacuum pump and a vacuum pump. The pneumatic thrust device can provide a fixed axial preload to the bearing, thereby ensuring the precise axial position of the rotor shaft and the axial clearance of the vacuum pump, which helps to improve the operational stability and lifespan of the vacuum pump.
[0008] In a first aspect, embodiments of this application provide a pneumatic thrust device for a vacuum pump. The vacuum pump includes a rotor shaft, a bearing plate, and a deep groove ball bearing. The rotor shaft passes through the bearing plate, and the deep groove ball bearing is disposed on the bearing plate and supports the rotor shaft. The pneumatic thrust device for the vacuum pump is disposed on the bearing plate, and a thrust portion is provided on the side of the pneumatic thrust device facing the bearing plate. The pneumatic thrust device for the vacuum pump is configured to drive the thrust portion to move axially along the rotor shaft by a constant gas pressure, so as to apply an axial preload to the deep groove ball bearing to constrain the axial position of the rotor shaft.
[0009] In one alternative embodiment, the vacuum pump pneumatic thrust device includes a cylinder housing and a piston;
[0010] The cylinder housing is disposed on the bearing plate, and the side of the cylinder housing facing the deep groove ball bearing is provided with an air chamber. The cylinder housing is provided with an air inlet, which is used to connect the air chamber to an air source. The air source is used to maintain a constant gas pressure in the air chamber.
[0011] The piston serves as the thrust unit and is disposed within the gas chamber. The piston can be driven by the constant gas pressure to move axially along the rotor shaft to apply axial preload to the deep groove ball bearing.
[0012] In one alternative embodiment, the side of the piston facing the deep groove ball bearing has a stepped surface.
[0013] In one alternative embodiment, the piston has an annular structure, and the axis of the piston coincides with the axis of the deep groove ball bearing.
[0014] In one alternative embodiment, the air chamber of the cylinder housing is an annular cavity conforming to the piston.
[0015] In one optional embodiment, the vacuum pump pneumatic thrust device further includes a one-way air inlet connector, which is disposed inside the air inlet and the air inlet is connected to the air source through the one-way air inlet connector.
[0016] In one optional embodiment, the vacuum pump pneumatic thrust device further includes a guide ring disposed within a guide groove of the piston to guide the axial movement of the piston and reduce friction.
[0017] In one optional embodiment, the vacuum pump pneumatic thrust device further includes a sealing ring disposed within the sealing groove of the piston to ensure the airtightness of the air chamber.
[0018] In one alternative embodiment, the sealing ring is made of a high-fluorine material.
[0019] Secondly, embodiments of this application also provide a vacuum pump, including a rotor shaft, a bearing plate, a deep groove ball bearing, and the vacuum pump pneumatic thrust device described above.
[0020] The above-mentioned technical solution of this application has the following beneficial technical effects:
[0021] The pneumatic thrust device for a vacuum pump according to this application embodiment can drive the thrust unit to move axially along the rotor shaft using constant gas pressure, thereby applying axial preload to the deep groove ball bearing to constrain the axial position of the rotor shaft. Compared to the traditional method of using springs to constrain the rotor shaft, this pneumatic thrust device can provide a fixed axial preload to the bearing, thus ensuring the precise axial position of the rotor shaft and avoiding the problem of reduced axial preload due to increased bearing clearance. This helps improve the operational stability and lifespan of the vacuum pump. Furthermore, by replacing springs, this pneumatic thrust device can also avoid the problem of the cumulative axial dimensional tolerances of multiple parts affecting the spring force, preventing excessive axial preload. It also helps reduce the axial dimensional accuracy requirements of related parts in the vacuum pump rotor shaft system, thereby reducing processing costs.
[0022] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. These drawings are incorporated in and constitute a part of this specification. They illustrate embodiments conforming to this application and, together with the specification, serve to explain the technical solutions of this application. It should be understood that the following drawings only show some embodiments of this application and should not be considered as limiting the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.
[0024] Figure 1 A schematic diagram of the structure of a vacuum pump provided in an embodiment of this application is shown;
[0025] Figure 2 It shows Figure 1 Schematic diagram of the gas thrust device of a medium vacuum pump;
[0026] Figure 3 It shows Figure 2 Top view of the gas thrust device of a medium vacuum pump;
[0027] Figure 4 It shows Figure 3 AA in the middle is a sectional view;
[0028] Figure 5 It shows Figure 4 A magnified view of part A in the image;
[0029] In the picture:
[0030] 1. Rotor shaft; 2. Bearing plate; 3. Deep groove ball bearing; 100. Vacuum pump gas thrust device; 110. Cylinder housing; 111. Air chamber; 112. Air inlet; 113. First air passage; 114. Second air passage; 115. Plug; 120. Piston; 130. One-way air inlet connector; 140. Guide ring; 150. Inner ring seal; 160. Outer ring seal. Detailed Implementation
[0031] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the present application.
[0032] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated 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 application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0033] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0034] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.
[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0036] refer to Figure 1 This application provides a vacuum pump, including a rotor shaft 1, a bearing plate 2, a deep groove ball bearing 3, and a vacuum pump pneumatic thrust device. The rotor shaft 1 passes through the bearing plate 2. The deep groove ball bearing 3 is disposed on the bearing plate 2 and supports the rotor shaft 1. The vacuum pump pneumatic thrust device is disposed on the bearing plate 2 and is used to apply an axial preload to the deep groove ball bearing 3 to constrain the axial position of the rotor shaft 1.
[0037] refer to Figure 1 and Figure 5 The vacuum pump pneumatic thrust device is equipped with a thrust section, which is configured to drive the thrust section to move axially along the rotor shaft 1 using constant gas pressure, thereby applying axial preload to the deep groove ball bearing 3 to constrain the axial position of the rotor shaft 1. This configuration allows the vacuum pump pneumatic thrust device to provide a fixed axial preload to the bearing, ensuring the precise axial position of the rotor shaft 1, maintaining the axial clearance of the vacuum pump, and contributing to improved operational stability and lifespan. In this embodiment, the thrust section is located on the side of the vacuum pump pneumatic thrust device facing the bearing plate 2 (or the deep groove ball bearing 3), and the end face of the thrust section contacts the outer ring end face of the deep groove ball bearing 3 to apply the axial preload.
[0038] Optionally, refer to Figures 2 to 5The vacuum pump pneumatic thrust device includes a cylinder housing 110 and a piston 120. The cylinder housing 110 is mounted on the bearing plate 2. An air chamber 111 is provided on the side of the cylinder housing 110 facing the deep groove ball bearing 3 (i.e., the side facing the bearing plate 2). An air inlet 112 is provided on the cylinder housing 110 to connect the air chamber 111 to an air source, which maintains a constant gas pressure within the air chamber 111. The piston 120 serves as the thrust unit and is located within the air chamber 111. The piston 120 can be driven by a constant gas pressure to move axially along the rotor shaft 1 to apply an axial preload to the deep groove ball bearing 3. Specifically, the pneumatic thrust device of the vacuum pump can be a cylinder device. When a certain pressure of gas is introduced into the gas chamber 111 by the gas source, the thrust part (piston 120) can move axially along the rotor shaft 1 within the gas chamber 111, so that the thrust part can automatically adapt to the changing axial position of the bearing, thereby maintaining the axial preload applied by the thrust part to the deep groove ball bearing 3. At the same time, since the gas source can maintain a constant gas pressure in the gas chamber 111, the thrust part can apply a fixed axial preload to the bearing while adapting to the bearing position. The stable axial preload can ensure the precise axial position of the rotor shaft 1, thereby ensuring the axial clearance of the vacuum pump and avoiding the problem of the axial preload decreasing due to the increase of bearing clearance, thus improving the operational stability and life of the vacuum pump.
[0039] In this embodiment, the cylinder housing 110 is fixedly connected to the bearing plate 2 to ensure the stability of the overall structure. For example, the cylinder housing 110 can be fixed to the bearing plate 2 with screws.
[0040] In this embodiment, an air passage is provided within the cylinder housing 110, and the air chamber 111 is connected to the air inlet 112 through the air passage. For example, as Figure 5 As shown, the air passage includes a first air passage 113 and a second air passage 114. The first air passage 113 extends radially along the cylinder housing 110, with one end connected to the air chamber 111 and the other end sealed by a screw plug 115. The second air passage 114 extends axially along the cylinder housing 110, with one end connected to the first air passage 113 and the other end sealed by a screw plug 115. The second air passage 114 is also connected to the air inlet 112. It should be understood that, to improve sealing, a sealing element can be provided between the screw plug 115 and the cylinder housing 110, such as wrapping Teflon tape around the surface of the screw plug 115 and installing it within the corresponding air passage.
[0041] In this embodiment, the air source can be a plant-side air source. That is, the vacuum pump pneumatic thrust device can use the same air source as the vacuum pump equipment for air supply, which reduces the corresponding equipment configuration and equipment costs. It should be noted that since the typical supply pressure of the plant-side air source is in the range of 5.5 bar to 7.5 bar, the end face dimensions of the piston 120 can be designed according to the supply pressure of the plant-side air source. For example, when the axial preload is known, and the supply pressure is 6.5 bar, the air source in the air chamber 111 is maintained at 6.5 bar. According to F = P * S, the area of the thrust section end face (i.e., the contact surface between the thrust section and the deep groove ball bearing 3) can be calculated.
[0042] Optionally, refer to Figure 2 and Figure 5 The side of piston 120 facing the deep groove ball bearing 3 is stepped. An exemplary embodiment of this application shows a stepped protrusion in the middle of the side of piston 120 facing the deep groove ball bearing 3. This configuration allows piston 120 to contact the deep groove ball bearing 3 through the step on its end face and apply axial preload, reducing interference from the surrounding environment on piston 120.
[0043] Optionally, refer to Figure 2 and Figure 3 The piston 120 has a ring structure, and its axis coincides with the axis of the deep groove ball bearing 3. That is to say, when the thrust part moves axially along the rotor shaft 1, the thrust part can uniformly apply axial thrust to different positions around the deep groove ball bearing 3. This can avoid uneven wear of internal components caused by local stress on the bearing and help improve the stability of the structure.
[0044] Optionally, refer to Figure 4 The cylinder housing 110 has an annular cavity 111 that conforms to the piston 120. In other words, in a specific configuration, the annular piston 120 is entirely installed inside the annular cavity. This allows the piston 120 to be evenly stressed in the circumferential direction, preventing the piston 120 from becoming misaligned due to uneven stress, which could lead to uneven wear of the bearing.
[0045] Optionally, refer to Figures 2 to 5 The vacuum pump pneumatic thrust device also includes a one-way air inlet connector 130, which is disposed within the air inlet 112. The air inlet 112 is connected to the air source through the one-way air inlet connector 130. Specifically, the one-way air inlet connector 130 only allows gas to flow into the air chamber 111 of the cylinder housing 110 in one direction, which can prevent gas backflow from causing pressure fluctuations and affecting the reliability of the device. It should be understood that, in order to improve sealing, a sealing element can be provided between the one-way air inlet connector 130 and the cylinder housing 110, such as wrapping PTFE tape around the surface of the one-way air inlet connector 130 and then installing it inside the air inlet 112.
[0046] In this embodiment, a one-way air intake connector 130 is disposed on the outer peripheral surface of the cylinder housing 110. Correspondingly, an air intake port 112 of the cylinder housing 110 is also disposed on the outer peripheral surface of the cylinder housing 110.
[0047] Optionally, refer to Figure 5 The vacuum pump pneumatic thrust device also includes a guide ring 140, which is disposed within a guide groove of the piston 120 to guide the axial movement of the piston 120 and reduce friction. Specifically, the guide ring 140 has an annular structure, and the outer circumferential surface of the piston 120 is provided with a guide groove conforming to the guide ring 140. The guide ring 140 is installed within the guide groove. In actual use, the piston 120 contacts the inner wall of the cylinder housing 110 through the guide ring 140, constraining the piston 120 to move only axially, preventing the piston 120 from tilting or jamming due to uneven gas pressure. In specific implementations, the guide ring 140 can be made of polytetrafluoroethylene (PTFE), and the surface of the guide ring 140 can be coated with grease. This not only facilitates the insertion of the guide ring 140 into the guide groove but also helps reduce the resistance during the axial movement of the piston 120.
[0048] Optionally, refer to Figure 5 The vacuum pump pneumatic thrust device also includes a sealing ring, which is disposed within the sealing groove of the piston 120 to ensure the sealing performance of the gas chamber 111. An exemplary embodiment of this application shows that the inner circumferential surface of the piston 120 is provided with an inner ring sealing groove, and the outer circumferential surface of the piston 120 is provided with an outer ring sealing groove. The sealing ring includes an inner ring sealing ring 150 and an outer ring sealing ring 160. The inner ring sealing ring 150 is disposed within the inner ring sealing line, and the outer ring sealing ring 160 is disposed within the outer ring sealing groove. In specific implementations, the surfaces of the inner and outer sealing rings can be coated with grease before installation in the corresponding sealing grooves. This not only facilitates the installation of the sealing rings but also helps reduce the resistance during the axial movement of the piston 120. It should be understood that both the inner and outer sealing rings are made of high-fluorine material to adapt to the operating environment temperature of the vacuum pump pneumatic thrust device (i.e., the operating temperature of the vacuum pump, up to a maximum of 150°C).
[0049] The manufacturing method of the vacuum pump pneumatic thrust device according to the embodiments of this application includes:
[0050] S101. Determine the bearing type and model based on the axial and radial loads of rotor shaft 1 during operation, and calculate the required axial preload of the bearing as 1500N based on the bearing type and model.
[0051] S102. Calculate the thrust section end face area based on the axial preload of the bearing and the air pressure of the air source (the air supply pressure is in the range of 5.5 bar to 7.5 bar; in this embodiment, the air supply pressure is selected as 6.5 bar), that is, S = F / P.
[0052] S103. Design the dimensions and structure of the vacuum pump pneumatic thrust device according to the end face area of the thrust section and the installation space, including the cylinder housing 110 dimension, piston 120 dimension, guide ring 140 dimension, inner sealing ring 150 dimension and outer sealing ring 160 dimension.
[0053] S104. Based on the design results of step S103, establish a three-dimensional model of the vacuum pump pneumatic thrust device, including the three-dimensional models of cylinder housing 110, piston 120, guide ring 140, inner sealing ring 150 and outer sealing ring 160.
[0054] S105. Use ANSYS finite element analysis software to simulate whether the thrust of the vacuum pump pneumatic thrust device meets the design requirements at the operating temperature. That is, simulate whether the cylinder thrust meets the design requirement of 1500N when the cylinder inlet pressure is 6.5 bar at an operating temperature of 150℃ (vacuum pump operating temperature).
[0055] S106. Based on the design results of step S103, process the pneumatic thrust device of the vacuum pump, that is, process the cylinder housing 110, piston 120, guide ring 140, inner ring seal 150 and outer ring seal 160 designed in step S103, and assemble them into a pneumatic thrust device of the vacuum pump.
[0056] S107, Test the thrust performance of the vacuum pump pneumatic thrust device and the temperature resistance performance of each component in test step S106.
[0057] S108. Optimize the size and structure of each part of the vacuum pump pneumatic thrust device based on the test results of step S107.
[0058] The pneumatic thrust device for a vacuum pump according to this application embodiment can drive the thrust unit to move axially along the rotor shaft 1 through constant gas pressure, thereby applying axial preload to the deep groove ball bearing 3 to constrain the axial position of the rotor shaft 1. Compared with the conventional method of using springs to constrain the rotor shaft 1, this pneumatic thrust device can provide a fixed axial preload to the bearing, thus ensuring the precise axial position of the rotor shaft 1 and avoiding the problem of reduced axial preload due to increased bearing clearance, which helps improve the operational stability and lifespan of the vacuum pump. Furthermore, by replacing the spring, this pneumatic thrust device can also avoid the problem of the cumulative axial dimensional tolerances of multiple parts affecting the spring force, preventing excessive axial preload, and helping to reduce the axial dimensional accuracy requirements of related parts of the vacuum pump rotor shaft system, thereby reducing processing costs.
[0059] One or more embodiments in this specification are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this specification should be included within the scope of protection of this application.
[0060] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A vacuum pump aerodynamic thrust device, said vacuum pump comprising a rotor shaft, a bearing plate and a deep groove ball bearing, said rotor shaft being disposed in said bearing plate, said deep groove ball bearing being disposed in said bearing plate and supporting said rotor shaft, characterized in that, The vacuum pump pneumatic thrust device is disposed on the bearing plate. A thrust part is disposed on the side of the vacuum pump pneumatic thrust device facing the bearing plate. The vacuum pump pneumatic thrust device is configured to drive the thrust part to move axially along the rotor shaft by constant gas pressure, so as to apply axial preload to the deep groove ball bearing and constrain the axial position of the rotor shaft.
2. A vacuum pump gas dynamic thrust device according to claim 1, characterized in that The vacuum pump pneumatic thrust device includes a cylinder housing and a piston; The cylinder housing is disposed on the bearing plate, and the side of the cylinder housing facing the deep groove ball bearing is provided with an air chamber. The cylinder housing is provided with an air inlet, which is used to connect the air chamber to an air source. The air source is used to maintain a constant gas pressure in the air chamber. The piston serves as the thrust unit and is disposed within the gas chamber. The piston can be driven by the constant gas pressure to move axially along the rotor shaft to apply axial preload to the deep groove ball bearing.
3. A vacuum pump gas dynamic thrust device according to claim 2, characterised in that, The side of the piston facing the deep groove ball bearing is a stepped surface.
4. A vacuum pump gas dynamic thrust device according to claim 2, characterised in that, The piston has an annular structure, and the axis of the piston coincides with the axis of the deep groove ball bearing.
5. A vacuum pump gas dynamic thrust device according to claim 4, characterised in that, The air chamber of the cylinder housing is an annular cavity conforming to the piston.
6. A vacuum pump gas dynamic thrust device according to claim 2, characterised in that, The vacuum pump pneumatic thrust device also includes a one-way air inlet connector, which is disposed inside the air inlet and the air inlet is connected to the air source through the one-way air inlet connector.
7. A vacuum pump gas dynamic thrust device according to claim 2, characterised in that, The vacuum pump pneumatic thrust device also includes a guide ring, which is disposed in the guide groove of the piston to guide the axial movement of the piston and reduce friction.
8. A vacuum pump gas dynamic thrust device according to claim 2, characterised in that, The vacuum pump pneumatic thrust device also includes a sealing ring, which is disposed in the sealing groove of the piston to ensure the airtightness of the air chamber.
9. A vacuum pump gas dynamic thrust device according to claim 8, characterised in that, The sealing ring is made of high-fluorine material.
10. A vacuum pump, characterized in that, It includes a rotor shaft, a bearing plate, a deep groove ball bearing, and the pneumatic thrust device for a vacuum pump as described in any one of claims 1-9.