Gulp valve for screw vacuum pump

Abstract

The gulp valve comprises a valve body, a valve cavity is arranged in the valve body, a first gas port, a second gas port and a third gas port which are respectively communicated with the valve cavity are arranged on the valve body, the first gas port is connected to a pump head of the screw vacuum pump, the second gas port is communicated with the atmosphere, and the third gas port is used for being communicated with negative pressure gas. A valve port is formed between the first air port and the second air port, a valve element correspondingly matched with the valve port and a spring correspondingly matched with the valve element are movably arranged in the valve cavity, and the spring enables the valve element to have the movement trend of closing the valve port all the time. And when the third gas port is communicated with negative pressure gas, the valve element overcomes the elastic acting force of the spring to move in the direction far away from the valve port under the suction effect of the negative pressure gas so as to open the valve port. The device is simple and reasonable in structure, convenient to install and reliable in operation. When the pump head stops working, air is supplemented to the pump head through the air supplementing valve so as to balance the negative pressure in the pump head, and the lubricating oil in the oil separation barrel can be effectively prevented from being sucked into the pump head.

Description

Technical Field

[0001] This utility model relates to the field of vacuum equipment, and in particular to a gas supply valve for a screw vacuum pump. Background Technology

[0002] When the screw vacuum pump is working, negative pressure gas is delivered into the pump head through the inlet valve. As the screw rotates, the negative pressure gas is compressed inside the pump head and delivered to the oil separator. Throughout the entire working process, the pump head remains under negative pressure.

[0003] When the screw vacuum pump stops working, the pump head remains under negative pressure. This causes lubricating oil from the oil separator connected to the pump head to be drawn into the pump head, resulting in lubricating oil accumulation in the rotor clearance and inlet area. When the screw vacuum pump restarts, the accumulated lubricating oil significantly increases the rotor's rotational resistance, leading to a sudden increase in starting current and potentially triggering motor overload protection or causing starting failure.

[0004] Therefore, it is necessary to improve the existing technology. Utility Model Content

[0005] The purpose of this utility model is to address the defects and deficiencies of the existing technology by providing a gas replenishment valve for a screw vacuum pump. The gas replenishment valve is provided between the inlet valve and the pump head. When the pump head stops working, gas is replenished into the pump head through the gas replenishment valve to balance the negative pressure and prevent the lubricating oil in the oil separator from being sucked into the pump head.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A gas supply valve for a screw vacuum pump includes a valve body with a valve cavity inside. The valve body has a first port, a second port, and a third port, each communicating with the valve cavity. The first port is connected to the pump head of the screw vacuum pump, the second port is open to the atmosphere, and the third port is used to connect to a negative pressure gas. A valve port is located between the first and second ports. A valve core corresponding to the valve port and a spring corresponding to the valve core are movably disposed within the valve cavity. The spring abuts against the valve core, ensuring that the valve core always tends to close the valve port. When the third port is connected to a negative pressure gas, the valve core, under the suction force of the negative pressure gas, overcomes the elastic force of the spring and moves away from the valve port, thereby opening the valve port.

[0008] Furthermore, the valve core divides the valve cavity into a first cavity and a second cavity, the valve core extends from the first cavity into the second cavity, the first air port and the second air port are both connected to the second cavity, and the third air port is connected to the first cavity.

[0009] Furthermore, the valve core has a ring pressing part and a sealing part, the cross-sectional area of ​​the sealing part is smaller than the cross-sectional area of ​​the ring pressing part; the outer peripheral wall of the ring pressing part is sealed to the inner wall of the first cavity, and the outer peripheral wall of the sealing part is sealed to the inner wall of the second cavity.

[0010] Furthermore, the first air inlet, the sealing part, and the ring pressure part are all arranged concentrically and coaxially.

[0011] Furthermore, the ring pressure section divides the first cavity into a first chamber and a second chamber, the spring is disposed in the first chamber, and the third air port communicates with the first chamber.

[0012] Furthermore, the valve body is provided with a breather hole that communicates with the second chamber.

[0013] Furthermore, a first O-ring is provided between the ring pressing part and the inner wall of the first cavity; a second O-ring is provided between the sealing part and the inner wall of the second cavity; and a third O-ring is provided between the sealing part and the inner wall of the valve port.

[0014] Furthermore, the valve body is provided with an end cap for sealing the valve cavity, and a fourth O-ring is provided between the end cap and the valve body.

[0015] Furthermore, the end cap is provided with a receiving groove that matches the outer circumferential dimensions of the spring; the end of the valve core facing the spring is provided with a guiding part, which is used to guide the spring.

[0016] With the above structure, the beneficial effects of this utility model are as follows: The air replenishment valve for a screw vacuum pump described in this utility model has a simple and reasonable structure, is easy to install and maintain, and responds promptly and operates reliably. When the pump head stops working, the air replenishment valve replenishes the pump head in a timely manner to balance the negative pressure inside the pump head, effectively preventing the lubricating oil in the oil separator from being sucked into the pump head. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a cross-sectional view of the overall structure of this utility model;

[0020] Figure 3 This is the utility modelFigure 2 Enlarged schematic diagram of the structure at point A;

[0021] Figure 4 This is a cross-sectional view of the valve body of this utility model;

[0022] Figure 5 This is a three-dimensional structural diagram of the valve core of this utility model;

[0023] Figure 6 This is the pneumatic principle of this utility model. Figure 1 (When the pump head is working);

[0024] Figure 7 This is the pneumatic principle of this utility model. Figure 2 (When the pump head stops working).

[0025] Figures 1 to 7 The winning number is:

[0026] 1. Valve body; 11. Valve chamber; 111. First chamber; 1111. First cavity; 1112. Second cavity; 112. Second cavity; 12. First air port; 13. Second air port; 14. Third air port; 15. Valve port; 16. Breathing hole; 17. End cap; 171. Fourth O-ring seal; 172. Receiving groove; 2. Spring; 3. Valve core; 31. Ring pressing part; 311. First O-ring seal; 32. Sealing part; 321. Second O-ring seal; 322. Third O-ring seal; 33. Guide part; 4. Solenoid valve; 41. Air port P; 42. Air port S; 43. Working port A; 100. Air supply valve; 200. Pump head. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0028] In the description of this utility model, it should be understood that if terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, the term "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] In this utility model, unless otherwise explicitly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact, or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this invention are for illustrative purposes only and do not represent the only possible implementation.

[0033] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] like Figures 1 to 7 As shown, a gas supply valve for a screw vacuum pump includes a valve body 1, within which a valve cavity 11 is provided. The valve body 1 has a first gas port 12, a second gas port 13, and a third gas port 14, each communicating with the valve cavity 11. The first gas port 12 is connected to the pump head 200 of the screw vacuum pump. The second gas port 13 is connected to the atmosphere. The third gas port 14 is used to connect to a negative pressure gas. A valve port 15 is provided between the first gas port 12 and the second gas port 13. A valve core 3 corresponding to the valve port 15 and a spring 2 corresponding to the valve core 3 are movably disposed within the valve cavity 11. The spring 2 abuts against the valve core 3, ensuring that the valve core 3 always has a tendency to close the valve port 15. When the third gas port 14 is connected to a negative pressure gas, the valve core 3, under the suction force of the negative pressure gas, overcomes the elastic force of the spring 2 and moves away from the valve port 15, thereby opening the valve port 15. The valve core 3 divides the valve chamber 11 into a first chamber 111 and a second chamber 112. The valve core 3 extends from the first chamber 111 into the second chamber 112. The first air port 12 and the second air port 13 are both connected to the second chamber 112, and the third air port 14 is connected to the first chamber 111. The ring pressure part 31 divides the first chamber 111 into a first chamber 1111 and a second chamber 1112. The spring 2 is disposed in the first chamber 1111, and the third air port 14 is connected to the first chamber 1111. The valve body 1 is provided with a breather hole 16 that communicates with the second chamber 1112.

[0035] In this embodiment, the screw vacuum pump includes a pump head 200, and the gas supply valve 100 is connected to the pump head 200. A solenoid valve 4 is connected to the third gas port 14. When the pump head 200 is working, the solenoid valve 4 is energized; when the pump head 200 stops working, the solenoid valve 4 is de-energized. When the solenoid valve 4 is energized, the third gas port 14 is connected to the atmosphere; when the solenoid valve 4 is de-energized, the third gas port 14 is connected to the pump head 200, allowing the negative pressure gas inside the pump head 200 to enter the valve chamber 11 through the third gas port 14. Under the suction force of the negative pressure gas, the valve core 3 overcomes the elastic force of the spring 2 and moves away from the valve port 15 to open the valve port 15. The solenoid valve 4 is a two-position three-way solenoid valve 4. The solenoid valve 4 includes an air port P41, an air port S42, and a working port A43. The working port A43 is connected to the third air port 14. The air port P41 is connected to the atmosphere. The air port S42 is connected to the pump head 200. When the solenoid valve 4 is energized, the working port A43 is connected to the air port P41. When the solenoid valve 4 is de-energized, the working port A43 is connected to the air port S42.

[0036] Based on the above embodiments, the present invention aims to provide a gas replenishment valve for a screw vacuum pump, which has a simple and reasonable structure, is easy to install and maintain, and has a timely response and reliable operation. When the pump head 200 stops working, the gas replenishment valve 100 replenishes the pump head 200 with gas to balance the negative pressure inside the pump head 200, effectively preventing the lubricating oil in the oil separator from being sucked into the pump head 200.

[0037] In this embodiment, the operation of the air supply valve 100 is as follows: when the pump head 200 is working, such as... Figure 6 As shown, when the solenoid valve 4 is energized, the working port A43 is connected to the air port P41, and atmospheric air enters the first chamber 1111 of the first cavity 111 through the air port P41, the working port A43, and the third air port 14. At this time, the valve core 3 closes the valve port 15 under the elastic force of the spring 2, and the air supply valve 100 is in a non-working state. When the pump head 200 stops working, the pump head 200 is in a negative pressure state, and the solenoid valve 4 is in a de-energized state. Figure 7 As shown, the working port A43 is connected to the air port S42. The negative pressure gas in the pump head 200 enters the first chamber 1111 of the first cavity 111 from the air port S42, the working port A43, and the third air port 14. Under the suction of the negative pressure gas, the valve core 3 overcomes the elastic force of the spring 2 and moves away from the valve port 15 to open the valve port 15. When the valve port 15 is open, the first air port 12 is connected to the second air port 13. Atmospheric air enters the pump head 200 from the first air port 12, the valve port 15, and the second air port 13 to replenish the pump head 200, thereby balancing the negative pressure in the pump head 200 and effectively preventing the lubricating oil in the oil separator from being sucked into the pump head 200.

[0038] In another preferred embodiment of this utility model, the valve core 3 has a ring pressing portion 31 and a sealing portion 32, wherein the cross-sectional area of ​​the sealing portion 32 is smaller than the cross-sectional area of ​​the ring pressing portion 31; the outer peripheral wall of the ring pressing portion 31 is sealed to the inner wall of the first cavity 111, and the outer peripheral wall of the sealing portion 32 is sealed to the inner wall of the second cavity 112. A first O-ring seal 311 is provided between the ring pressing portion 31 and the inner wall of the first cavity 111; a second O-ring seal 321 is provided between the sealing portion 32 and the inner wall of the second cavity 112; and a third O-ring seal 322 is provided between the sealing portion 32 and the inner wall of the valve port 15. In this embodiment, as... Figure 2 and Figure 3 As shown, when the pump head 200 stops working, the solenoid valve 4 is de-energized. At this time, the first air port 12 and the third air port 14 are respectively connected to the negative pressure gas in the pump head 200. However, since the cross-sectional area of ​​the sealing part 32 is smaller than the cross-sectional area of ​​the ring pressure part 31, the valve core 3 overcomes the elastic force of the spring 2 and moves away from the valve port 15. During this process, the atmosphere enters the second chamber 1112 of the first chamber 111 through the breather hole 16. When the valve core 3 moves to open the valve port 15, the first air port 12 is connected to the second air port 13, so that the atmosphere enters the pump head 200 through the second air port 13, the valve port 15 and the first air port 12 to balance the negative pressure in the pump head 200, which can effectively prevent the lubricating oil from being sucked into the pump head 200. After the negative pressure inside the pump head 200 is balanced, the negative pressure in the first chamber 1111 of the first cavity 111 connected to the pump head 200 is also balanced. Under the elastic force of the spring 2, the valve core 3 moves towards the valve port 15. At this time, the gas in the second chamber 1112 of the first cavity 111 is discharged through the breather hole 16 until the sealing part 32 closes the valve port 15. The first O-ring seal 311 is provided to increase the airtightness between the first chamber 1111 and the second chamber 1112. The second O-ring seal 321 is provided to increase the airtightness between the second chamber 1112 and the second air port 13. The third O-ring seal 322 is provided to increase the airtightness between the first air port 12 and the second air port 13 (when the valve port 15 is closed).

[0039] In another preferred embodiment of this utility model, the first air port 12, the sealing part 32, and the ring pressing part 31 are all arranged concentrically and coaxially. In this embodiment, as... Figure 2 As shown, this structural design helps to ensure the coaxiality and smoothness of the valve core 3 during movement.

[0040] As another preferred embodiment of this utility model, the valve body 1 is provided with an end cap 17 for sealing the valve cavity 11, and a fourth O-ring seal 171 is provided between the end cap 17 and the valve body 1. The end cap 17 is provided with a receiving groove 172 that matches the outer circumferential size of the spring 2; a guiding part 33 is provided at the end of the valve core 3 facing the spring 2, and the guiding part 33 is used to guide the spring 2. In this embodiment, as... Figure 1 As shown, the end cap 17 facilitates the installation and subsequent maintenance of the internal components of the valve body 1, and the fourth O-ring seal 171 is used to improve the airtightness between the end cap 17 and the valve body 1. The valve core 3 has a guide part 33 at the end facing the spring 2, and the end cap 17 has a receiving groove 172 that matches the outer circumferential size of the spring 2. One end of the spring 2 is fitted around the outer circumference of the guide part 33, and the other end of the spring 2 abuts against the receiving groove 172. This structural design prevents the spring 2 from tilting or shifting during the movement of the valve core 3.

[0041] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this utility model.

Claims

1. A gas supply valve for a screw vacuum pump, comprising a valve body (1), characterized in that: The valve body (1) is provided with a valve cavity (11). The valve body (1) is provided with a first air port (12), a second air port (13), and a third air port (14) respectively communicating with the valve cavity (11). The first air port (12) is connected to the pump head (200) of the screw vacuum pump. The second air port (13) is connected to the atmosphere. The third air port (14) is used to connect to negative pressure gas. A valve port (15) is provided between the first air port (12) and the second air port (13). The valve cavity ( 11) The inner movable part is equipped with a valve core (3) corresponding to the valve port (15) and a spring (2) corresponding to the valve core (3). The spring (2) abuts against the valve core (3) so that the valve core (3) always has the tendency to close the valve port (15). When the third gas port (14) is connected to the negative pressure gas, the valve core (3) overcomes the elastic force of the spring (2) under the suction of the negative pressure gas and moves away from the valve port (15) to open the valve port (15).

2. The gas supply valve for a screw vacuum pump according to claim 1, characterized in that: The valve core (3) divides the valve chamber (11) into a first chamber (111) and a second chamber (112). The valve core (3) extends from the first chamber (111) into the second chamber (112). The first air port (12) and the second air port (13) are both connected to the second chamber (112). The third air port (14) is connected to the first chamber (111).

3. The gas supply valve for a screw vacuum pump according to claim 2, characterized in that: The valve core (3) has a ring pressing part (31) and a sealing part (32). The cross-sectional area of ​​the sealing part (32) is smaller than that of the ring pressing part (31). The outer peripheral wall of the ring pressing part (31) is sealed to the inner wall of the first cavity (111), and the outer peripheral wall of the sealing part (32) is sealed to the inner wall of the second cavity (112).

4. The gas supply valve for a screw vacuum pump according to claim 3, characterized in that: The first air inlet (12), the sealing part (32) and the ring pressure part (31) are all arranged concentrically and coaxially.

5. The gas supply valve for a screw vacuum pump according to claim 3, characterized in that: The ring pressure part (31) divides the first cavity (111) into a first chamber (1111) and a second chamber (1112), the spring (2) is disposed in the first chamber (1111), and the third air port (14) is connected to the first chamber (1111).

6. The gas supply valve for a screw vacuum pump according to claim 5, characterized in that: The valve body (1) is provided with a breathing hole (16) that communicates with the second chamber (1112).

7. The gas supply valve for a screw vacuum pump according to claim 3, characterized in that: A first O-ring seal (311) is provided between the ring pressing part (31) and the inner wall of the first cavity (111); a second O-ring seal (321) is provided between the sealing part (32) and the inner wall of the second cavity (112); and a third O-ring seal (322) is provided between the sealing part (32) and the inner wall of the valve port (15).

8. The gas supply valve for a screw vacuum pump according to claim 1, characterized in that: The valve body (1) is provided with an end cap (17) for sealing the valve cavity (11), and a fourth O-ring (171) is provided between the end cap (17) and the valve body (1).

9. The gas supply valve for a screw vacuum pump according to claim 8, characterized in that: The end cap (17) is provided with a receiving groove (172) that matches the outer circumferential size of the spring (2); the valve core (3) is provided with a guide part (33) at one end facing the spring (2), and the guide part (33) is used to guide the spring (2).

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