Vacuum pump pressure balance structure, vacuum pump rotor and vacuum pump

Abstract

The application relates to a vacuum pump pressure balancing structure, a vacuum pump rotor and a vacuum pump. The vacuum pump comprises a stator and a rotor, the stator is provided with a cavity, the rotor comprises a rotor shaft and a rotor element, the rotor shaft is rotatably arranged in the cavity, a sealing device for sealing the cavity is arranged between the rotor shaft and the stator, the rotor element is arranged on the rotor shaft, an axial gap is formed between the end surface of the rotor element and the stator wall, and the rotor element and the stator enclose an air inlet side and an air outlet side. The pressure balancing structure comprises a pressure relief path arranged on the rotor shaft and the end surface of the rotor element, and the pressure relief path is used for connecting the air inlet side and the air outlet side to balance the pressure between the air inlet side and the air outlet side in the axial gap. The vacuum pump pressure balancing structure can balance the pressure difference between the air inlet side and the air outlet side in the axial gap, thereby reducing the pressure on both sides of the sealing device, reducing the amount of gas passing through the sealing device, and prolonging the service life of the sealing device.

Description

Technical Field

[0001] This application relates to the field of vacuum pump technology, and more specifically, to a vacuum pump pressure balancing structure, a vacuum pump rotor, and a vacuum pump. Background Technology

[0002] In a vacuum pump system, the sealing device is a key component. It isolates the stator working chamber from the lubrication chamber, preventing gas leakage or impurity intrusion, and directly affects the performance of the vacuum pump. On the one hand, poor vacuum can significantly reduce the pumping efficiency, failing to meet the required vacuum level for production, thus impacting product quality. For example, in semiconductor chip manufacturing, even minor vacuum leaks can cause internal structural defects in the chip. On the other hand, process gases entering the lubrication chamber can cause lubricant emulsification, accelerate component wear, increase equipment maintenance costs, and result in substantial economic losses for the company.

[0003] Currently, common dry vacuum pumps typically use shaft seals for sealing. When the vacuum pump starts, stops, or its operating conditions change, the internal pressure of the stator changes instantaneously, while the external environmental pressure is usually relatively stable. This results in a large pressure difference on both sides of the sealing device. This pressure difference causes process gas to flow towards the sealing device, thereby corroding the sealing device and reducing its service life. Utility Model Content

[0004] This application provides at least one vacuum pump pressure balancing structure, vacuum pump rotor, and vacuum pump. The pressure balancing structure can balance the pressure difference between the inlet and outlet sides within the axial clearance, reduce the pressure difference on both sides of the sealing device, reduce the amount of gas passing through the sealing device, thereby reducing the corrosion of the sealing device by process gas and improving the service life of the sealing device.

[0005] In a first aspect, embodiments of this application provide a vacuum pump pressure balancing structure. The vacuum pump includes a stator and a rotor. The stator has a cavity, and the rotor includes a rotor shaft and rotor elements. The rotor shaft is rotatably disposed in the cavity via bearings. The rotor elements are disposed on the rotor shaft and located in the cavity. The rotor elements and the stator enclose an inlet side and an outlet side. When the rotor elements rotate, they compress the process gas on the inlet side and push it towards the outlet side. An axial gap exists between the end face of the rotor elements and the stator wall. A sealing device is provided between the rotor shaft and the stator to seal the cavity. The pressure balancing structure includes at least one pressure relief path. The pressure relief path is disposed on the end faces of the rotor shaft and the rotor elements. The pressure relief path is used to connect the inlet side and the outlet side to balance the pressure on the inlet side and the outlet side within the axial gap.

[0006] In one alternative implementation, the pressure relief path includes two interfaces and a through hole;

[0007] The interface is located on the end face of the rotor element. When the rotor element rotates, one of the two interfaces is connected to the air inlet side and the other is connected to the air outlet side.

[0008] The through hole is provided on the rotor shaft, and the through hole is used to connect the two interfaces so that the air inlet side and the air outlet side are connected.

[0009] In one alternative embodiment, the interface is a groove disposed on the inner ring of the end face of the rotor element.

[0010] In one alternative implementation, the interfaces are symmetrically distributed with respect to the axis of the rotor shaft.

[0011] In one alternative embodiment, the through hole is a hole that extends radially through the rotor shaft.

[0012] In one alternative implementation, when there are multiple pressure relief paths, the through holes intersect and are interconnected.

[0013] In one optional embodiment, when there are multiple pressure relief paths, the through holes are located at the axial position of the rotor shaft corresponding to the interface, and are distributed radially at intervals along the rotor shaft.

[0014] In one alternative embodiment, the rotor includes multiple stages of rotor elements, and the pressure balancing structure is disposed on the rotor shaft and the first stage rotor element as well as the rotor shaft and the last stage rotor element.

[0015] Secondly, embodiments of this application also provide a vacuum pump rotor, which is provided with the vacuum pump pressure balancing structure described in any of the first aspects.

[0016] Thirdly, embodiments of this application also provide a vacuum pump, including the vacuum pump rotor described in the second aspect.

[0017] The above-mentioned technical solution of this application has the following beneficial technical effects:

[0018] The vacuum pump pressure balancing structure of this application embodiment can connect the inlet side and the outlet side, so that the process gas can enter the low-pressure side from the high-pressure side of the inlet side and the outlet side through the pressure balancing structure to balance the pressure difference between the inlet side and the outlet side in the axial gap. This can reduce the pressure difference on both sides of the sealing device, thereby reducing the amount of gas passing through the sealing device. This can reduce the corrosion of the sealing device by the process gas and help improve the service life of the sealing device.

[0019] 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

[0020] 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.

[0021] Figure 1 A schematic diagram of the structure of a vacuum pump provided in an embodiment of this application is shown;

[0022] Figure 2 It shows Figure 1 Sectional view of AA;

[0023] Figure 3 It shows Figure 1 A radial sectional view of the fifth-stage rotor element and rotor shaft;

[0024] In the picture:

[0025] 1. Stator; 11. Inlet side; 12. Outlet side; 13. Exhaust pipe; 2. First end plate; 3. Second end plate; 4. Rotor shaft; 41. Through hole; 5. Rotor element; 51. Interface; 6. Sealing device; 7. Gearbox; 71. Gear; 8. Rear cover plate; 9. Motor. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] refer to Figure 1 and Figure 2 This application provides a vacuum pump, including a stator 1, a pair of meshing rotors, a gearbox 7, a rear cover plate 8, and a motor 9. The stator 1 has a cavity and an exhaust pipe 13 connected to the cavity. The stator 1 has a first end plate 2 and a second end plate 3 located at opposite ends of the cavity. The rotors include a rotor shaft 4 and rotor elements 5. The rotor shaft 4 is rotatably mounted in the cavity via bearings. The rotor elements 5 are mounted on the rotor shaft 4 and located within the cavity. An axial clearance exists between the end face of the rotor elements 5 and the wall of the stator 1. The rotor elements 5 and the stator 1 enclose an inlet side 11 and an outlet side 12. When the rotor elements 5 rotate, they compress the process gas in the inlet side 11 and push it towards the outlet side 12, where it is then discharged through the exhaust pipe 13. The gearbox 7 is located on the first end plate 2 and connected to the rotor shaft 4. The rear cover plate 8 is located on the second end plate 3. The motor 9 is located in the gearbox 7 and connected to the gear 71 inside the gearbox 7. The motor 9 is used to transmit power to the rotor shaft 4 through the gear 71 and drive the rotor shaft 4 to rotate the rotor element 5.

[0032] In this embodiment, the stator 1 includes multi-stage pump chambers. For example... Figure 1 As shown, from left to right, the stator 1 contains a first-stage pump chamber, a second-stage pump chamber, a third-stage pump chamber, a fourth-stage pump chamber, and a fifth-stage pump chamber. Of course, the stator 1 can also have more than five stages or fewer than five stages.

[0033] In this embodiment, both rotors include multi-stage rotor elements 5, each stage of rotor element 5 is located within its respective pump chamber, and the two rotor elements 5 of the same stage mesh with each other. For example... Figure 1 As shown, from left to right, each rotor is sequentially equipped with a first-stage rotor element, a second-stage rotor element, a third-stage rotor element, a fourth-stage rotor element, and a fifth-stage rotor element. The first-stage rotor elements of two rotors mesh in the first-stage pump chamber, the second-stage rotor elements mesh in the second-stage pump chamber, the third-stage rotor elements mesh in the third-stage pump chamber, the fourth-stage rotor elements mesh in the fourth-stage chamber, and the fifth-stage rotor elements mesh in the fifth-stage pump chamber. It should be understood that the number of stages of rotor element 5 should be consistent with the number of stages of the pump chamber.

[0034] In this embodiment, each stage of rotor element 5 is enclosed with the stator 1 to form an air inlet side 11 and an air outlet side 12. Specifically, two first-stage rotor elements are enclosed with the stator 1 to form the air inlet side 11 and the air outlet side 12 of the first-stage pump chamber; two second-stage rotor elements are enclosed with the stator 1 to form the air inlet side 11 and the air outlet side 12 of the second-stage pump chamber; two third-stage rotor elements are enclosed with the stator 1 to form the air inlet side 11 and the air outlet side 12 of the third-stage pump chamber; two fourth-stage rotor elements are enclosed with the stator 1 to form the air inlet side 11 and the air outlet side 12 of the fourth-stage pump chamber; and two fifth-stage rotor elements are enclosed with the stator 1 to form the air inlet side 11 and the air outlet side 12 of the fifth-stage pump chamber. The outlet side 12 of the first-stage pump chamber is connected to the inlet side 11 of the second-stage pump chamber, the outlet side 12 of the second-stage pump chamber is connected to the inlet side 11 of the third-stage pump chamber, the outlet side 12 of the third-stage pump chamber is connected to the inlet side 11 of the fourth-stage pump chamber, the outlet side 12 of the fourth-stage pump chamber is connected to the inlet side 11 of the fifth-stage pump chamber, and the outlet side 12 of the fifth-stage pump chamber is connected to the exhaust pipe 13. When the two rotors rotate synchronously, the flow direction of the process gas is as follows: inlet side 11 of the first stage pump chamber → outlet side 12 of the first stage pump chamber → inlet side 11 of the second stage pump chamber → outlet side 12 of the second stage pump chamber → inlet side 11 of the third stage pump chamber → outlet side 12 of the third stage pump chamber → inlet side 11 of the fourth stage pump chamber → outlet side 12 of the fourth stage pump chamber → inlet side 11 of the fifth stage pump chamber → outlet side 12 of the fifth stage pump chamber → exhaust pipe 13.

[0035] refer to Figure 1In this embodiment, a sealing device 6 with a sealing cavity is provided between the rotor shaft 4 and the stator 1. Specifically, a sealing device 6 (such as an axial lip seal) is provided between the rotor shaft 4 and the first end plate 2 and the second end plate 3 of the stator 1, respectively.

[0036] refer to Figure 2 In this embodiment, the rotor element 5 of the rotor has a five-bladed structure. Of course, the rotor element 5 can also be a three-bladed structure, a six-bladed structure, etc.

[0037] refer to Figure 2 In this embodiment, the rotor is provided with a pressure balancing structure, which includes at least one pressure relief path located on the end faces of the rotor shaft 4 and rotor element 5. The pressure relief path connects the inlet side 11 and the outlet side 12 to balance the pressures of the inlet side 11 and the outlet side 12 within the axial clearance. Specifically, the pressure balancing structure connects the inlet side 11 and the outlet side 12, allowing process gas to enter the low-pressure side from the high-pressure side of the inlet side 11 and the outlet side 12 via the pressure balancing structure. This balances the pressure difference between the inlet side 11 and the outlet side 12 within the axial clearance, thereby reducing the pressure difference across the sealing device 6 and consequently reducing the amount of gas passing through the sealing device 6, which helps to improve the service life of the sealing device 6. It should be understood that, in specific configurations, both rotors can be provided with a pressure balancing structure.

[0038] Optionally, a pressure balancing structure is provided on the rotor shaft 4 and the fifth-stage rotor element (i.e., the last-stage rotor element). This arrangement allows the outlet side 12 of the fifth-stage pump chamber to be connected to the inlet side 11, so that high-pressure process gas that cannot be discharged from the exhaust pipe 13 in time can flow to the inlet side 11 of the fifth-stage pump chamber through the pressure relief path, thereby balancing the pressure difference between the inlet side 11 and the outlet side 12 of the fifth-stage pump chamber. This reduces the amount of gas passing through the sealing device 6 to the right, and thus reduces the corrosion of the sealing device 6 by the process gas.

[0039] Optionally, a pressure balancing device is installed on the rotor shaft 4 and the first-stage rotor element. This arrangement allows the outlet side 12 of the first-stage pump chamber to be connected to the inlet side 11. When the pressure on the inlet side 11 is too high, the gas on the inlet side 11 can flow to the outlet side 12 through the pressure relief path to balance the pressure difference between the inlet side 11 and the outlet side 12 of the first-stage pump chamber. This reduces the amount of gas passing through the sealing device 6 to the left, thereby reducing the corrosion of the sealing device 6 by the process gas.

[0040] refer to Figure 2In this embodiment, the pressure relief path includes two interfaces 51 and one through hole 41. The interfaces 51 are located on the end face of the rotor element 5. When the rotor element 5 rotates, one of the two interfaces 51 is connected to the intake side 11, and the other is connected to the outlet side 12. The through hole 41 is located on the rotor shaft 4 and connects the two interfaces 51 to allow the intake side 11 and the outlet side 12 to communicate. In other words, the pressure relief path can be formed by two interfaces 51 and one through hole 41, and this pressure relief path allows the intake side 11 and the outlet side 12 to remain connected.

[0041] refer to Figure 2 In this embodiment, interface 51 is a groove provided on the inner ring of the end face of rotor element 5. Compared with an open hole design, providing a groove does not completely interrupt the material continuity of the rotor, which helps to maintain high structural strength and rigidity and reduces stress concentration points caused by an open hole. In addition, compared with a complex open hole design, a groove on the inner ring of the end face is generally easier to process, especially under high precision requirements, and can be completed using more common turning or grinding processes.

[0042] refer to Figure 2 In this embodiment, the interfaces 51 are symmetrically distributed relative to the axis of the rotor shaft 4. Specifically, the two interfaces 51 of the pressure relief path can be located on the same diameter extension line of the rotor shaft 4. Correspondingly, the through hole 41 can be a hole that penetrates the radial direction of the rotor shaft 4.

[0043] refer to Figure 2 In this embodiment, when there are multiple pressure relief paths, the interfaces 51 are distributed circumferentially along the rotor shaft 4.

[0044] refer to Figure 2 In this embodiment, when there are multiple pressure relief paths, the through holes 41 intersect and are interconnected. This arrangement allows the pressure to be evenly distributed across the different pressure relief paths, accelerating the response speed and improving the overall pressure relief efficiency.

[0045] refer to Figure 3 In this embodiment, when there are multiple pressure relief paths, the through holes 41 are located at the axial position of the rotor shaft 4 corresponding to the interface 51, and are distributed radially at intervals along the rotor shaft 4. This arrangement ensures that the through holes are radially distributed and aligned with the axial direction of the interface, avoiding the meandering flow or turbulence that may result from conventional axial distribution, thereby reducing flow resistance and improving transmission efficiency.

[0046] The vacuum pump pressure balancing structure of this application embodiment can connect the inlet side 11 and the outlet side 12, so that the process gas can enter the low-pressure side from the high-pressure side of the inlet side 11 and the outlet side 12 through the pressure balancing structure to balance the pressure difference between the inlet side 11 and the outlet side 12 in the axial gap. This can reduce the pressure difference on both sides of the sealing device 6, thereby reducing the amount of gas passing through the sealing device 6. This can reduce the corrosion of the sealing device 6 by the process gas and help improve the service life of the sealing device 6.

[0047] 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 protection scope of this application.

[0048] 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 pressure equalization structure, said vacuum pump comprising a stator and a pair of mutually engaging rotors, said stator having a cavity therein, said rotors comprising a rotor shaft rotatably disposed in said cavity by a bearing and a rotor element disposed on said rotor shaft and within said cavity, said rotor element and said stator enclosing an intake side and an exhaust side, said rotor element upon rotation compressing and pushing process gas from said intake side to said exhaust side, characterized by, There is an axial gap between the end face of the rotor element and the stator wall. A sealing device is provided between the rotor shaft and the stator to seal the cavity. The pressure balancing structure includes at least one pressure relief path. The pressure relief path is provided on the end face of the rotor shaft and the rotor element. The pressure relief path is used to connect the air inlet side and the air outlet side to balance the pressure of the air inlet side and the air outlet side within the axial gap. ​ 2. The vacuum pump pressure balancing structure according to claim 1, characterized in that, The pressure relief path includes two interfaces and one through hole; The interface is located on the end face of the rotor element. When the rotor element rotates, one of the two interfaces is connected to the air inlet side and the other is connected to the air outlet side. The through hole is provided on the rotor shaft, and the through hole is used to connect the two interfaces so that the air inlet side and the air outlet side are connected.

3. The vacuum pump pressure balancing structure according to claim 2, characterized in that, The interface is a groove located on the inner ring of the end face of the rotor element.

4. The vacuum pump pressure balancing structure according to claim 2, characterized in that, The interfaces are symmetrically distributed with respect to the axis of the rotor shaft.

5. The vacuum pump pressure balancing structure according to claim 2, characterized in that, The through hole is a hole that extends radially through the rotor shaft.

6. The vacuum pump pressure balancing structure according to claim 2, characterized in that, When there are multiple pressure relief paths, the through holes intersect and are interconnected.

7. The vacuum pump pressure balancing structure according to claim 2, characterized in that, When there are multiple pressure relief paths, the through holes are located at the axial position of the rotor shaft corresponding to the interface, and are distributed at radial intervals along the rotor shaft.

8. The vacuum pump pressure balancing structure according to claim 1, characterized in that, The rotor includes multiple stages of rotor elements, and the pressure balancing structure is disposed on the rotor shaft and the first stage rotor element, as well as on the rotor shaft and the last stage rotor element.

9. A vacuum pump rotor, characterized in that, It is equipped with the vacuum pump pressure balancing structure as described in any one of claims 1-8.

10. A vacuum pump, characterized in that, Includes the vacuum pump rotor as described in claim 9.

Images