Pump body of hybrid vacuum pump

Abstract

The utility model discloses a pump body of a hybrid vacuum pump, which comprises a pump body, a roots pump body cavity and a screw pump body cavity are arranged in the pump body, an air outlet of the roots pump body cavity is communicated with an air inlet of the screw pump body cavity, and an air outlet of the screw pump body cavity is arranged far away from the air inlet of the screw pump body cavity. The screw pump is characterized in that the pump body is further provided with a connecting air channel, the air inlet end of the connecting air channel is communicated with an air inlet of the screw pump body cavity, and the air outlet end of the connecting air channel is communicated with an air outlet of the screw pump body cavity; a one-way valve is further arranged in the connecting air channel. According to the utility model, the operation stability of the vacuum pump is effectively improved, and the vacuumizing effect is ensured.

Description

Technical Field

[0001] The utility model relates to a vacuum pump, in particular to a pump body of a hybrid vacuum pump. Background Art

[0002] A vacuum pump refers to a device or equipment that evacuates a container to be evacuated by mechanical, physical, chemical, or physical-chemical methods to obtain a vacuum. Generally speaking, a vacuum pump is a device that improves, generates, and maintains a vacuum in a closed space by various methods.

[0003] Among them, in order to improve the vacuum pumping effect, generally, when pumping vacuum, a vacuum pump group mechanism is adopted, that is, a combination of multiple vacuum pumps is used to achieve efficient vacuum pumping. Among them, for example, the application number: 202410723922.9, patent name: An integrated vacuum system, which uses a combination of multiple vacuum pumps. At the front end, a large-air-volume vacuum pump is used, and at the back end, a small-air-volume vacuum pump is used. For example, the application number: 202410723796.7, patent name: A two-axis hybrid pump, application number: 202410723744.X, patent name: A three-axis hybrid pump, which is a small-air-volume hybrid vacuum pump. The air inlet of the small-air-volume vacuum pump (for example, the air extraction volume per hour is 600 cubic meters per hour) is connected to a large-air-volume vacuum pump (for example, 3000 cubic meters per hour) or a buffer tank. In the hybrid pump, the air extraction volume of the screw pump is less than that of the roots pump. Therefore, when the vacuum pump group just starts working, the air pressure at the outlet of the large-air-volume vacuum pump at the front end is relatively large, and the exhaust volume of the screw pump in the hybrid pump is smaller than the exhaust volume of the roots pump in the hybrid pump. At this time, the screw pump is too late to discharge the gas, which will cause the vacuum pumping to be unsmooth and affect the vacuum pumping effect. Therefore, how to solve the above technical problems is the direction that those skilled in the art need to work hard on. Summary of the Invention

[0004] The purpose of the utility model is to provide a pump body of a hybrid vacuum pump, which can improve the smoothness of vacuum pumping of the vacuum pump and ensure the vacuum pumping effect of the vacuum pump by using this structure.

[0005] To achieve the above purpose, the technical solution adopted by the utility model is: a pump body of a hybrid vacuum pump, including a pump body. A roots pump body cavity and a screw pump body cavity are arranged in the pump body. The air outlet of the roots pump body cavity is communicated with the air inlet of the screw pump body cavity. The air outlet of the screw pump body cavity is arranged far away from the air inlet of the screw pump body cavity. A connecting air passage is also arranged on the pump body. The air inlet end of the connecting air passage is communicated with the air inlet of the screw pump body cavity, and the air outlet end of the connecting air passage is communicated with the air outlet of the screw pump body cavity;

[0006] A one-way valve is also arranged in the connecting air passage.

[0007] In the above technical solution, a first notch and a second notch are provided on the side wall of the pump body. The first notch is communicated with the air inlet of the screw pump body cavity, and the second notch is communicated with the air outlet of the screw pump body cavity. A connecting block is further installed on the side wall of the pump body. An air passage is provided in the connecting block, and both ends of the air passage are respectively communicated with the first notch and the second notch. The air passage, the first notch and the second notch form the connecting air passage.

[0008] In the above technical solution, the first notch and the second notch are arranged at the bottom of the pump body, and the connecting block is installed on the bottom surface of the pump body.

[0009] In the above technical solution, the air passage is of a U-shaped structure. The air passage includes an intermediate air passage and two end air passages respectively communicated with the intermediate air passage. The intermediate air passage is arranged inside the connecting block. The top of the end air passage is communicated with the top surface of the connecting block. The bottoms of the two end air passages are respectively communicated with both sides of the intermediate air passage. The two end air passages are respectively arranged opposite to the first notch and the second notch.

[0010] In the above technical solution, two annular grooves are provided on the top surface of the connecting block. Each annular groove is respectively arranged outside one of the end air passages. A sealing ring is installed in each annular groove, and the top surface of the sealing ring abuts against the bottom surface of the pump body.

[0011] In the above technical solution, one end of the intermediate air passage is arranged inside the connecting block, and the other end of the intermediate air passage is communicated with the end face of the connecting block. And a sealing cover for sealing the end of the intermediate air passage is provided at the end of the connecting block.

[0012] In the above technical solution, the one-way valve restricts the gas from flowing from the air outlet end of the connecting air passage towards the air inlet end of the connecting air passage.

[0013] In the above technical solution, the connecting air passage is arranged below the screw pump body cavity. The one-way valve is a floating ball valve. The one-way valve includes a floating ball. A vertically arranged floating ball chamber is provided at the air outlet end of the connecting air passage. The floating ball chamber communicates the connecting air passage with the air outlet of the screw pump body cavity;

[0014] An arc-shaped groove matching the outer surface of the bottom of the floating ball is provided on the bottom surface of the floating ball chamber, and the floating ball is arranged in the floating ball chamber.

[0015] In the above technical solution, the floating ball drops downward under the action of gravity and abuts against the arc-shaped groove, so that the connecting air passage is not communicated with the air outlet of the screw pump body cavity;

[0016] The blowing through the connecting air duct pushes up the floating ball, so that the connecting air duct is communicated with the air outlet of the screw pump body cavity.

[0017] In the above technical solution, there are two floating ball valves and two floating ball chambers. The two floating ball chambers are arranged at intervals, and each floating ball chamber respectively communicates the air outlet end of the connecting air duct with the air outlet of the screw pump body cavity;

[0018] A floating ball is respectively arranged in each floating ball chamber, and the bottom outer surface of the floating ball abuts against the bottom surface of the arc-shaped groove.

[0019] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:

[0020] 1. In the utility model, a connecting air duct is arranged in the pump body to communicate the air inlet of the screw pump body cavity with the air outlet of the screw pump body cavity, and a check valve is arranged in the connecting air duct, so that the gas that the screw pump fails to discharge in time in the high-pressure gas instantaneously sent into the mixing pump by the roots pump can be discharged through the connecting air duct, which can effectively ensure the smoothness and stability of the vacuum pumping of the mixing vacuum pump, especially improve the stability during the startup process of the vacuum pump;

[0021] 2. After the operation stability of the vacuum pump in the utility model, when the suction force generated during the operation of the screw pump is transmitted to the connecting channel, it can be blocked by the check valve, so that the gas will not be redrawn from the air outlet of the screw pump body cavity, and the suction force generated by the screw pump body cavity will be all transmitted to the roots pump body cavity at the front end, ensuring the vacuum pumping effect and stability of the vacuum pump;

[0022] 3. In the utility model, the check valve adopts a floating ball valve, and the self-weight of the floating ball of the floating ball valve is used to realize the function of the check valve, so that the gas can only flow unidirectionally from the air inlet of the screw pump body cavity towards the air outlet direction and cannot flow from the air outlet of the screw pump body cavity towards the air inlet direction of the screw pump body cavity, ensuring the vacuum pumping effect and stability of the vacuum pump;

[0023] 4. In the utility model, a first notch and a second notch are respectively arranged on the side wall of the pump body to communicate with the air inlet and the air outlet of the screw pump body cavity, and then a connecting block is installed on the outer wall of the pump body to communicate the first notch and the second notch. This not only facilitates the processing of the pump body and the connecting air duct, but also can be modified and processed on the basis of the original vacuum pump, reducing costs and facilitating maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the first embodiment of the utility model;

[0025] Figure 2 It is a partial enlarged view of the connection part between the connecting block and the pump body in the figure;

[0026] Figure 3 It is a schematic cross-sectional structure diagram of the connection between the check valve and the pump body in the first embodiment of the present utility model.

[0027] Among them: 1. Pump body; 2. Roots pump body cavity; 3. Screw pump body cavity; 4. Air outlet of the Roots pump body cavity; 5. Air inlet of the screw pump body cavity; 6. Air outlet of the screw pump body cavity; 7. Connecting air passage; 8. Check valve; 9. Coupling shaft; 10. Roots rotor component; 11. Screw rotor component; 12. First notch; 13. Second notch; 14. Connecting block; 15. Air passage; 16. Intermediate air passage; 17. End air passage; 18. Sealing ring; 19. Sealing cover; 20. Floating ball; 21. Floating ball chamber; 22. Arc-shaped groove. Specific embodiments

[0028] The present utility model will be further described below in conjunction with the drawings and embodiments:

[0029] Embodiment 1: Refer to Figures 1 to 3 As shown, a pump body of a hybrid vacuum pump includes a pump body 1. A Roots pump body cavity 2 and a screw pump body cavity 3 are provided inside the pump body 1. The air outlet 4 of the Roots pump body cavity is communicated with the air inlet 5 of the screw pump body cavity. The air outlet 6 of the screw pump body cavity is arranged away from the air inlet 5 of the screw pump body cavity. A connecting air passage 7 is further provided on the pump body 1. The air inlet end of the connecting air passage 7 is communicated with the air inlet 5 of the screw pump body cavity, and the air outlet end of the connecting air passage 7 is communicated with the air outlet 6 of the screw pump body cavity;

[0030] A check valve 8 is further provided in the connecting air passage 7. The check valve 8 restricts the flow of gas from the air outlet end of the connecting air passage 7 towards the air inlet end of the connecting air passage 7.

[0031] In this embodiment, two or three coupling shafts 9 are provided inside the pump body. The coupling shafts penetrate into the cavity of the screw pump body and the cavity of the roots pump body. There are meshing roots rotor components 10 in the cavity of the roots pump body, and meshing screw rotor components 11 are provided in the cavity of the screw pump body. The roots rotor components are installed on the coupling shafts in the cavity of the roots pump body, and the screw rotor components are installed on the coupling shafts in the cavity of the screw rotor pump body. The working principle of the pump body is similar to or the same as that of the patent application with the application number: 202410723796.7 and the patent name: A two-axis hybrid pump, and the patent application with the application number: 202410723744.X and the patent name: A three-axis hybrid pump. During operation, gas enters the cavity of the roots pump body from the air inlet of the roots pump body, and then through the rotation of the roots rotor components, the gas flows from the air outlet of the roots pump body and enters the air inlet of the screw pump body cavity. Then, the rotating screw rotor components pump the gas at the air inlet of the screw pump body cavity to the air outlet of the screw pump body cavity and discharge it from the air outlet of the screw pump body cavity. Among them, the air inlet of the roots pump body cavity is connected to the air outlet of a large-air-volume vacuum pump or a gas storage tank. At the moment of startup, the air intake is relatively large, and the amount of gas sent from the roots pump body cavity to the air inlet of the screw pump body cavity will exceed the pumping capacity of the screw rotor components, resulting in poor vacuum pumping effect. Therefore, through the setting of the connecting airway, the gas exceeding the pumping capacity of the screw rotor components will flow into the connecting airway and be discharged from the air outlet of the screw pump body cavity after passing through the one-way valve. When the instantaneous large air volume gradually decreases and the amount of gas sent from the roots pump body cavity to the screw pump body cavity is less than or equal to the pumping capacity of the screw rotor components, the negative pressure generated during the rotation of the screw rotor components will send the gas from the roots pump body cavity through the screw pump body cavity and discharge it from the air outlet of the screw pump body cavity. At the same time, during this process, the negative pressure generated during the rotation of the screw rotor components will also be transmitted to the connecting airway to pump the connecting airway. However, due to the presence of the one-way valve, the gas cannot flow from the air outlet end of the connecting airway towards the air inlet end of the connecting airway. Therefore, the connecting airway is equivalent to a one-way closed airway that is only connected to the inlet of the screw pump body cavity at this time. Therefore, the gas sent from the roots pump body cavity will not directly flow from the connecting airway to the air outlet of the screw pump body cavity, thus ensuring that the negative pressure during the rotation of the screw rotor components acts on the roots pump body cavity and ensuring the vacuum pumping effect and vacuum pumping stability.

[0032] See Figure 1 , 2As shown, a first notch 12 and a second notch 13 are provided on the side wall of the pump body 1. The first notch 12 communicates with the air inlet 5 of the screw pump body cavity, and the second notch 13 communicates with the air outlet 6 of the screw pump body cavity. A connecting block 14 is also installed on the side wall of the pump body 1. An air passage 15 is provided in the connecting block 14. Both ends of the air passage 15 are respectively connected to the first notch 12 and the second notch 13. The air passage 15, the first notch 12 and the second notch 13 constitute the connecting air passage 7.

[0033] In this embodiment, for the convenience of machining the pump body and the connecting air passage, and also for the convenience of adding or modifying the connecting air passage on the pump body of the original vacuum pump, a first notch and a second notch are directly opened on the side wall of the pump body to communicate with the air inlet and the air outlet of the screw pump body cavity respectively, and then a separate connecting block is provided, and an air passage is machined in the connecting block so that the first notch, the second notch and the air passage constitute the connecting air passage. This is convenient for machining the connecting air passage and also for modifying or adding to the pump body of the original vacuum pump, which can effectively reduce the machining difficulty and cost. Especially when modifying the pump body of the original vacuum pump, there is no need to replace the pump body, further reducing the cost.

[0034] Among them, the first notch, the second notch and the connecting block can be opened at the top, front side, rear side or bottom of the pump body, and can be selected according to the actual structure of the pump body.

[0035] Preferably, in this embodiment, the first notch and the second notch are provided at the bottom of the pump body, and the connecting block is installed on the bottom surface of the pump body.

[0036] See Figure 1 、 2 As shown, the air passage 15 is of a U-shaped structure. The air passage 15 includes an intermediate air passage 16 and two end air passages 17 respectively communicating with the intermediate air passage 16. The intermediate air passage 16 is arranged inside the connecting block 14. The top of the end air passage 17 communicates with the top surface of the connecting block 14. The bottoms of the two end air passages 17 are respectively connected to both sides of the intermediate air passage 16. The two end air passages 17 are respectively arranged facing the first notch 12 and the second notch 13.

[0037] An air passage of U-shaped structure is adopted, so that both ends of the U-shaped air passage face the first notch and the second notch respectively, thereby connecting the air inlet of the screw pump body cavity and the air outlet of the screw pump body cavity.

[0038] See Figure 1 、 2As shown, two annular grooves are provided on the top surface of the connecting block 14, each annular groove is respectively disposed outside one of the end air passages 17, and a sealing ring 18 is installed in each annular groove. The top surface of the sealing ring 18 abuts against the bottom surface of the pump body 1.

[0039] Through the arrangement of the annular grooves and the sealing rings, after the connecting block and the pump body are installed, by means of the sealing rings, the connection between the corresponding notch and the end air passage is sealed, preventing air leakage at the connection between the corresponding notch and the end air passage.

[0040] See Figure 1 、 2 As shown, one end of the intermediate air passage 16 is disposed in the connecting block 14, the other end of the intermediate air passage 16 is communicated with the end face of the connecting block 14, and a sealing cover 19 for sealing the end of the intermediate air passage 16 is provided at the end of the connecting block 14.

[0041] In this embodiment, since the air passage is of a U-shaped structure and is directly arranged in the connecting block, it is not convenient for processing. Therefore, one end of the intermediate air passage is communicated with the end face of the connecting block, which is convenient for the processing of the air passage. After the air passage is processed, the end of the intermediate air passage is sealed by the sealing cover, so that the gas enters the intermediate air passage from one end air passage and then is sent out from the other end air passage, and the gas will not leak from other positions of the intermediate air passage.

[0042] When the air passage needs to be processed in the connecting block, the intermediate air passage of the connecting block is directly processed from one end of the connecting block. After the intermediate air passage is processed, two end air passages are processed from the top surface of the connecting block, and finally the end of the intermediate air passage is sealed by the sealing cover, and the processing of the connecting air passage can be realized.

[0043] See Figures 1 to 3 As shown, the connecting air passage 7 is disposed below the screw pump body cavity 3. The one-way valve 8 is a float valve. The one-way valve 8 includes a floating ball 20. A vertically arranged floating ball chamber 21 is provided at the air outlet end of the connecting air passage 7. The floating ball chamber 21 communicates the connecting air passage 7 with the air outlet 6 of the screw pump body cavity.

[0044] An arc-shaped groove 22 matching the outer surface of the bottom of the floating ball 20 is provided on the bottom surface of the floating ball chamber 21. The floating ball 20 is disposed in the floating ball chamber 21.

[0045] The floating ball 20 drops downward under gravity and abuts against the arc-shaped groove 22, so that the connecting air passage 7 is not communicated with the air outlet 6 of the screw pump body cavity.

[0046] When the connecting air passage 7 blows air, the floating ball 20 is lifted up, so that the connecting air passage 7 is communicated with the air outlet 6 of the screw pump body cavity.

[0047] In this embodiment, the connecting air passage is arranged below the cavity of the screw pump body and is close to the bottom of the pump body. Therefore, a float valve is adopted as the check valve, and it has a float ball inside. Under normal circumstances, the float ball falls on the arc-shaped groove due to its own weight. In this way, if the air pressure of the gas flowing from the inlet of the screw pump body cavity into the connecting air passage is not sufficient to lift the float ball, other gases cannot directly pass through the connecting air passage and be discharged from the air outlet of the screw pump body cavity. If the air pressure entering the connecting air passage is relatively large, the float ball can be directly lifted, making the connecting air passage communicate with the air outlet of the screw pump body cavity, and the gas can directly pass through the connecting air passage and be discharged from the air outlet of the screw pump body cavity. At the same time, when the screw rotor component rotates to generate negative pressure, the negative pressure will be transmitted to the connecting air passage and the Roots pump body cavity. The gas in the Roots pump body cavity will flow towards the screw pump body cavity, and the negative pressure in the connecting air passage will be transmitted to the float ball, making the float ball fit more tightly on the arc-shaped groove of the float ball chamber, blocking the connecting air passage and the air outlet of the screw pump body cavity, so that the gas at the air outlet of the screw pump body cavity cannot be sucked by the screw rotor component, and only the gas sent by the Roots pump body cavity can be sucked, thus realizing the function of unidirectional gas flow.

[0048] See Figure 3 As shown, there are two float valves and two float ball chambers. The two float ball chambers are arranged at intervals, and each float ball chamber respectively communicates the air outlet end of the connecting air passage with the air outlet of the screw pump body cavity;

[0049] A float ball is respectively arranged in each float ball chamber, and the outer surface of the bottom of the float ball abuts against the bottom surface of the arc-shaped groove.

[0050] In this embodiment, the structure of double float ball chambers and double float balls is adopted, which can improve the exhaust efficiency of the connecting air passage.

[0051] In this embodiment, the float ball chamber is arranged in the second notch.

[0052] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0053] In the present utility model, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or an integral one; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, for example, the two can form a mechanical abutment or abutment connection through abutment, contact, etc., the two can also be directly hung or hung through an intermediate medium, etc., or it can be the internal connection of the two elements or the interaction relationship between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. The pump body of a hybrid vacuum pump, comprising a pump body, wherein a Roots pump body cavity and a screw pump body cavity are arranged in the pump body, an air outlet of the Roots pump body cavity is communicated with an air inlet of the screw pump body cavity, and an air outlet of the screw pump body cavity is arranged away from the air inlet of the screw pump body cavity, and is characterized in that: A connecting air duct is further provided on the pump body. The air inlet end of the connecting air duct is communicated with the air inlet of the screw pump body cavity, and the air outlet end of the connecting air duct is communicated with the air outlet of the screw pump body cavity; A check valve is further provided in the connecting air duct.

2. The pump body of the hybrid vacuum pump according to claim 1, characterized in that: A first notch and a second notch are provided on the side wall of the pump body. The first notch is communicated with the air inlet of the screw pump body cavity, and the second notch is communicated with the air outlet of the screw pump body cavity. A connecting block is further installed on the side wall of the pump body. An air duct is provided in the connecting block. The two ends of the air duct are respectively communicated with the first notch and the second notch. The air duct, the first notch and the second notch form the connecting air duct.

3. The pump body of the hybrid vacuum pump according to claim 2, characterized in that: The first notch and the second notch are provided at the bottom of the pump body, and the connecting block is installed on the bottom surface of the pump body.

4. The pump body of the hybrid vacuum pump according to claim 3, characterized in that: The air duct is of a U-shaped structure. The air duct includes an intermediate air duct and two end air ducts respectively communicated with the intermediate air duct. The intermediate air duct is arranged inside the connecting block. The top of the end air duct is communicated with the top surface of the connecting block. The bottoms of the two end air ducts are respectively communicated with both sides of the intermediate air duct. The two end air ducts are respectively arranged opposite to the first notch and the second notch.

5. The pump body of the hybrid vacuum pump according to claim 4, characterized in that: Two annular grooves are provided on the top surface of the connecting block. Each annular groove is respectively arranged outside one of the end air ducts. A sealing ring is installed in each annular groove. The top surface of the sealing ring abuts against the bottom surface of the pump body.

6. The pump body of the hybrid vacuum pump according to claim 4, characterized in that: One end of the intermediate air duct is arranged inside the connecting block, and the other end of the intermediate air duct is communicated with the end face of the connecting block. And a sealing cover for sealing the end of the intermediate air duct is provided at the end of the connecting block.

7. The pump body of the hybrid vacuum pump according to claim 1, characterized in that: The check valve restricts the gas from flowing from the air outlet end of the connecting air duct towards the air inlet end of the connecting air duct.

8. The pump body of the hybrid vacuum pump according to claim 7, wherein: The connecting air duct is arranged below the screw pump body cavity. The check valve is a floating ball valve. The check valve includes a floating ball. A vertically arranged floating ball chamber is provided at the air outlet end of the connecting air duct. The floating ball chamber communicates the connecting air duct with the air outlet of the screw pump body cavity; An arc-shaped groove matching the outer surface of the bottom of the floating ball is provided on the bottom surface of the floating ball chamber. The floating ball is arranged in the floating ball chamber.

9. The pump body of the hybrid vacuum pump according to claim 8, characterized in that: The floating ball drops downward under the action of gravity and abuts against the arc-shaped groove, so that the connecting air duct is not communicated with the air outlet of the screw pump body cavity; Blowing air into the connecting air duct jacks up the floating ball, so that the connecting air duct is communicated with the air outlet of the screw pump body cavity.

10. The pump body of the hybrid vacuum pump according to claim 8, characterized in that: There are two floating ball valves and two floating ball chambers. The two floating ball chambers are arranged at intervals. Each floating ball chamber respectively communicates the air outlet end of the connecting air duct with the air outlet of the screw pump body cavity; A floating ball is respectively arranged in each floating ball chamber. The outer surface of the bottom of the floating ball abuts against the bottom surface of the arc-shaped groove.

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