Gas ballast valve with manual adjusting function

Abstract

The gas ballast valve with the manual adjusting function comprises a valve body, a gas inlet is formed in the side face of the valve body, the gas ballast valve further comprises an adjusting base, the adjusting base is installed at an end opening of the valve body in a threaded mode, and the bottom of the adjusting base is located below the gas inlet. A gap is formed between the outer side wall of the adjusting seat and the inner circumferential surface of the valve body, the gap is communicated with the air inlet, air introduced into the air inlet passes through the gap and then enters the pump cavity, and the adjusting seat is manually rotated to adjust the length of the gap. According to the gas ballast valve with the manual adjusting function, gap conductance is controlled by adjusting the length of the gap, so that the gas ballast amount is controlled, the adjusting mode is simple and reliable, the adjusting stability is good, clamping stagnation is not prone to occurring, meanwhile, adjusting is conducted by rotating the adjusting base installed in a threaded mode, the adjusting distance is long, adjusting is fine, conductance change is more regular, and linear control can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of gas ballast valve technology and relates to a gas ballast valve with manual adjustment function. Background Technology

[0002] Liquids generally have a higher density than gases, and liquids have a stronger adsorption force on object surfaces, making them more likely to remain on the pump chamber surface. For oil-sealed mechanical vacuum pumps with working fluids, such as slide valve vacuum pumps, rotary vane vacuum pumps, and oil ring vacuum pumps, liquid contaminates the working fluid, increasing its saturated vapor pressure and reducing the sealing effect, thus lowering the pumping speed and ultimate vacuum of the oil-sealed vacuum pump. For dry vacuum pumps, such as dry screw vacuum pumps, Roots vacuum pumps, and reciprocating vacuum pumps, the liquid in the pump chamber evaporates during vacuum pump intake and liquefies during vacuum pump exhaust. The liquid remains in the pump chamber at all times and participates in the vacuum pumping process, occupying part or even all of the pumping efficiency, which greatly affects the performance of the vacuum pump. Therefore, when pumping condensable gases, mechanical vacuum pumps need to prevent the condensable gases from liquefying in the pump chamber. The mainstream method is to fill the pump chamber with a large amount of non-condensable gas through a gas ballast valve, reducing the proportion of condensable gases in the pump chamber. This prevents the condensable gases from reaching liquefaction pressure after compression in the pump chamber, allowing them to be discharged directly in gaseous state. The gas ballast charging volume is directly proportional to the mass flow rate of the condensable gas being pumped by the vacuum pump. Therefore, assuming the properties of the pumped gas remain constant, the lower the pump inlet pressure, the smaller the gas ballast charging volume required, and the higher the pump inlet pressure, the larger the gas ballast charging volume required. For pure condensable gases, the gas ballast charging volume is directly proportional to the pump inlet pressure.

[0003] However, the charging volume of existing gas ballast valves is not adjustable. During vacuum pump operation, the amount of gas that can be pumped in by existing gas ballast valves remains constant. For vacuum pumps of different volumes, this can easily lead to insufficient or excessive gas intake, resulting in an excessively small or large reduction in the vacuum pump's compression ratio. This can cause vapor condensation or low vacuum efficiency. Furthermore, some commercially available gas ballast valves with adjustable gas volume are essentially a combination of a regulating valve and a check valve. They use high-pressure media to directly charge the pump chamber (vacuum) to produce the gas ballast effect. However, the pressure ratio between the external high-pressure media and the gas in the pump chamber is very large, sometimes thousands or even tens of thousands of times. During charging, the gas volume expands proportionally, amplifying even small changes in the gas ballast charging volume. Therefore, it is difficult for general gas ballast valves to accurately adjust the gas volume. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by providing a gas ballast valve with manual adjustment function.

[0005] The objective of this invention can be achieved through the following technical solution: a gas ballast valve with manual adjustment function, comprising a valve body, an air inlet on the side of the valve body, and an adjustment seat, the adjustment seat being threadedly installed at the end opening of the valve body, the bottom of the adjustment seat being located below the air inlet, a gap being formed between the outer wall of the adjustment seat and the inner circumferential surface of the valve body, the gap communicating with the air inlet, gas introduced into the air inlet passing through the gap and entering the pump chamber, and the length of the gap being adjusted by manually rotating the adjustment seat.

[0006] In the aforementioned gas ballast valve with manual adjustment function, the side of the valve body is provided with an inflation volume scale, the top surface of the adjustment seat is close to the inflation volume scale, and the scale on the inflation volume scale is the standard inflation volume corresponding to different gap lengths.

[0007] In the aforementioned gas ballast valve with manual adjustment function, the inner circumferential surface of the valve body is provided with an annular groove, the annular groove is connected to the air inlet, and an annular channel is formed between the annular groove and the outer wall of the adjustment seat. The bottom of the annular channel is connected to the gap through a slope transition.

[0008] In the aforementioned gas ballast valve with manual adjustment function, the top of the adjustment seat is provided with a hexagonal inner hole.

[0009] In the aforementioned gas ballast valve with manual adjustment function, a flange is provided on the side of the top of the adjustment seat, and a set screw is passed through the flange. Rotating the set screw will cause the bottom of the set screw to contact the top surface of the valve body, thereby locking the valve body.

[0010] Compared with existing technologies, this gas ballast valve with manual adjustment function controls the flow conduction of the gap by adjusting the gap length, thereby controlling the amount of gas ballast. The adjustment method is simple and reliable, with good adjustment stability and is not prone to jamming. At the same time, it is adjusted by manually rotating the threaded adjustment seat, which has a long adjustment distance, fine adjustment, and more regular flow conduction changes, and can achieve linear control. The height indication is converted into a standard gas ballast inflation volume indication through the inflation volume scale, realizing quantifiable indication of the gas ballast volume, and the operation is simple and reliable. The annular channel is connected to the air inlet and fully connected to the gap to ensure stable air intake in the gap. Attached Figure Description

[0011] Figure 1 This is a cross-sectional structural diagram of a gas ballast valve with manual adjustment function.

[0012] Figure 2 This is a schematic diagram of the structure of a gas ballast valve with manual adjustment function.

[0013] In the diagram, 1. Adjusting seat; 101. Transition chamber; 102. Buffer groove; 103. Hexagonal inner hole; 104. Set screw; 2. Valve stem; 21. Limiting step; 3. Valve core; 31. Guide slope; 32. Limiting groove; 33. Vent hole; 4. Valve plate; 41. Rubber; 42. Metal spring plate; 5. Base; 51. Limiting slot; 52. Small hole; 6. Valve body; 61. Air inlet; 62. Gap; 63. Annular groove; 64. Sloping surface; 7. Spring; 8. Inflation scale; 9. First sealing ring; 10. Second sealing ring; 11. Locking nut; 12. Pressure gauge. Detailed Implementation

[0014] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0015] like Figure 1 and Figure 2 As shown, this gas ballast valve includes an adjusting seat 1, a valve stem 2, a valve core 3, a valve plate 4, a base 5, a valve body 6, and a spring 7. The adjusting seat 1 is threadedly installed at the end opening of the valve body 6. The spring 7, valve core 3, and valve plate 4 are located inside the valve body 6 and are sequentially mounted on the valve stem 2. Both ends of the valve stem 2 are threadedly connected to the adjusting seat 1 and the base 5, respectively. The valve core 3 has multiple vent holes 33 evenly distributed along its circumference. Both ends of the spring 7 abut against the adjusting seat 1 and the valve core 3, respectively. The elastic force of the spring 7 causes the valve core 3 to contact the valve plate 4, and the valve plate 4 to contact the base 5. The bottom of the valve body 6 is connected to the pump chamber. When the pressure difference between the upper and lower sides of the valve core 3 (the lower side of the valve core 3 is the pump chamber pressure) is greater than the elastic force of the spring 7, the valve core 3 will move upward under the high pressure of the pump chamber, the spring 7 will be compressed, the preload of the valve plate 4 will be reduced, and the reset distance of the valve plate 4 will be increased, thereby increasing the single opening time of the gas ballast valve and automatically increasing the gas ballast charging volume. This achieves the effect of automatically adjusting the charging volume according to the change of the vacuum pump inlet pressure, which is beneficial to improving the gas ballast effect and the effective pumping speed of the vacuum pump.

[0016] In the above technical solution: An air inlet 61 is provided on the side of the valve body 6. The bottom of the adjusting seat 1 is located below the air inlet 61. A gap 62 is formed between the outer wall of the adjusting seat 1 and the inner circumferential surface of the valve body 6. The gap 62 communicates with the air inlet 61. Gas introduced into the air inlet 61 enters the pump chamber after passing through the gap 62. The length of the gap 62 is adjusted by manually rotating the adjusting seat 1. The gas ballast volume is mainly determined by the flow conductance of the gap 62. The flow conductance of the gap is controlled by adjusting the length of the gap 62 by rotating the adjusting seat 1. A longer gap 62 results in greater resistance and a smaller flow conductance, making it difficult for gas to pass through; a shorter gap 62 results in less resistance and a larger flow conductance, making it easier for gas to pass through. The threaded fit between the adjusting seat 1 and the valve body 6 allows for a longer axial movement distance of the adjusting seat 1, thus resulting in a longer adjustment distance for the gap 62, finer adjustment, and more regular changes in flow conductance, achieving linear control. Simultaneously, the width of the gap 62 is fixed; only the length of the gap 62 is changed, making the adjustment method simple and reliable, with good adjustment stability and less prone to jamming.

[0017] In the above technical solution: the top of the adjusting seat 1 has a hexagonal inner hole 103, which facilitates the insertion of tools to rotate the adjusting seat 1 and generate an adjustment effect. The hexagonal inner hole 103 requires the use of a special wrench for adjustment, thereby avoiding accidental operation. The side of the top of the adjusting seat 1 is provided with a flange, and a set screw 104 passes through the flange. Rotating the set screw 104 makes the bottom of the set screw 104 contact the top surface of the valve body 6, locking the valve body 6 and preventing accidental rotation of the valve body 6. At the same time, the adjustment position can be recorded by the marks on the set screw 104 for accurate reset after maintenance.

[0018] In the above technical solution: A gas volume scale 8 is provided on the side of the valve body 6. The top surface of the adjusting seat 1 is close to the gas volume scale 8. The scale on the gas volume scale 8 represents the standard gas volume corresponding to different gap lengths 62. The height indication on the top surface of the adjusting seat 1 specifically indicates the gap length 62. The gas ballast gas volume calculated or experimentally calibrated under standard conditions based on different gap lengths 62 is directly marked on the gas volume scale 8 as a scale line, so that different gap lengths correspond to their corresponding standard gas volumes. At this time, the value on the gas volume scale 8 is read using the top surface of the adjusting seat 1 as an indicator; this value is the standard gas volume of the gas ballast valve at that time. The setting of the gas volume scale 8 simplifies the complex vacuum conductance calculation and mechanical adjustment into a simple "alignment" operation. The operator does not need to know the gap length or conductance formula; they only need to know the required gas ballast volume for the process to operate. The operation is simple and reliable.

[0019] In the above technical solution: a limiting groove 32 is formed at the bottom of the inner circumferential surface of the valve core 3, and a corresponding annular protruding limiting step 21 is provided on the side of the valve stem 2. The limiting step 21 is located within the limiting groove 32 and limits the installation position of the valve core 3. The bottom surface of the valve core 3 is a guide slope 31 that is inclined from the inside to the outside. The base 5 is approximately frustum-shaped, and a limiting slot 51 is formed between the base 5 and the bottom surface of the limiting step 21. The valve plate 4 is located below the limiting step 21. The inner end of the valve plate 4 is located within the limiting slot 51 and contacts the limiting step 21 and the base 5. The outer end of the valve plate 4 contacts the guide slope 31, thereby closing the vent 33. At the same time, a cavity exists on the upper surface of the valve plate 4.

[0020] In the above technical solution: the valve plate 4 includes a rubber 41 and a metal spring plate 42 embedded in the rubber 41. The metal spring plate 42 provides elasticity and maintains the overall shape, while the rubber 41 provides a sealing function, which can extend the service life of the valve plate 4, provide high stability, and prevent irregular twisting deformation. The inner hole of the valve plate 4 adopts a rounded transition to avoid local compression of the rubber near the inner hole of the valve plate 4 when the valve plate 4 undergoes disc-shaped deformation, and to prevent the rubber material from affecting the restoring force of the valve plate 4, thus maintaining a consistent restoring force. The outer end of the valve plate 4 adopts a rounded corner structure to ensure that the contact mode of the valve plate 4 is consistent when it contacts the valve core 3 at different angles, increasing the contact area of ​​the outer edge of the valve plate 4 and ensuring a sealing effect.

[0021] The combination of the limiting step 21 and the guide slope 31 ensures that a cavity always exists on the upper surface of the valve plate 4, thus preventing significant changes in the pressure-bearing area of ​​the valve plate 4 during operation and improving the accuracy of the valve plate 4's movement. Furthermore, it prevents the liquid viscosity from adversely affecting the valve plate 4's movement when the pump liquefies. Simultaneously, the combination of the limiting step 21 and the guide slope 31 ensures effective contact between the valve core 3 and the outer edge of the valve plate 4, improving the effective sealing between them and reducing gas backflow. It also reduces the contact area between the valve plate 4 and the valve core 3, increasing the contact strength at the valve plate 4's contact point and further enhancing the sealing effect of the valve plate 4.

[0022] The limiting slot 51 restricts the displacement of the valve disc 4, preventing it from moving horizontally or vertically. This makes the position of the valve core 3 the sole factor affecting the amount of disc deformation of the valve disc 4, thus achieving the purpose of changing the valve preload by altering the position of the valve core 3. Simultaneously, the limiting step 21 above the valve disc 4 and the frustum-shaped surface of the base 5 below the valve disc 4 limit the maximum upward disc deformation of the valve disc 4, preventing plastic deformation due to exceeding the elastic deformation range of the metal spring plate 42.

[0023] In the above technical solution: the base 5 is provided with a plurality of small holes 52 evenly distributed along the circumference. The small holes 52 reduce the contact area between the valve plate 4 and the base 5 and allow air to enter quickly between the valve plate 4 and the base 5, which can increase the reset speed and reset stability of the valve plate 4.

[0024] In the above technical solution: a first sealing groove is formed on the outer circumferential surface of the valve core 3, and a first sealing ring 9 is provided in the first sealing groove, which is in close contact with the inner circumferential surface of the valve body 6. A second sealing groove is formed on the valve stem 2, and a second sealing ring 10 is provided in the second sealing groove, which is in close contact with the inner circumferential surface of the valve core 3. The first sealing ring 9 and the second sealing ring 10 respectively seal the outer circumferential surface and the inner circumferential surface of the valve core 3, preventing gas from flowing through the gap between the inner and outer sides of the valve core 3. After the valve core 3 moves upward under high pressure, the friction of the first sealing ring 9 and the second sealing ring 10 is used to add a damping effect to the valve core 3, reducing the moving speed of the valve core 3 and preventing the valve core 3 from oscillating up and down; and making the valve core 3 stay in mid-air, realizing the function of automatically adjusting the preload and reset distance of the valve plate 4, thereby automatically adjusting the valve opening time and valve opening degree, and finally realizing the automatic adjustment of the gas ballast charging volume.

[0025] In the above technical solution: the inner circumferential surface of the valve body 6 is provided with an annular groove 63, which is connected to the air inlet 61. An annular channel is formed between the annular groove 63 and the outer wall of the adjusting seat 1. The bottom of the annular channel is connected to the gap 62 by a slope 64. The annular channel is connected to the air inlet 61 and fully connected to the gap 62 to ensure stable air intake at the gap 62.

[0026] In the above technical solution: the space between the bottom surface of the regulating seat 1 and the top surface of the valve core 3 is a transition cavity 101. The transition cavity 101 can greatly reduce the maximum pressure difference between the upper and lower surfaces of the valve plate 4, reduce the impact strength of the valve plate 4, thereby extending the life of the valve plate 4 and improving the stability of the valve. The bottom of the regulating seat 1 is provided with a buffer groove 102 that communicates with the transition cavity 101. The buffer groove 102 increases the volume of the transition cavity 101, significantly reducing the pressure fluctuation of the transition cavity 101, thereby improving the stability of the opening and closing action of the gas ballast valve.

[0027] In the above technical solution: a pressure gauge 12 is also provided on the side of the adjusting seat 1. The pressure gauge 12 is connected to the transition chamber 101 and is used to measure the pressure value of the transition chamber 101. Comparing the pressure value on the pressure gauge 12 with the reading of the inflation volume scale 8 can improve the accuracy of manual adjustment. It can also be used to check the working condition of the gas ballast valve. If the pressure changes while the scale remains unchanged, it indicates that the gas ballast valve is malfunctioning. When the pressure deviation exceeds the permissible value, the gas ballast valve needs to be maintained. At the same time, the pressure gauge 12 can also be used to detect whether the high-pressure gas source is properly connected and whether the gas source pressure is normal.

[0028] In the above technical solution: a locking nut 11 is also threadedly fixed to the bottom of the valve stem 2, and the locking nut 11 is located below the base 5.

[0029] In the above technical solution: the valve stem 2 and the adjusting seat 1 are specifically connected by a threaded fixed connection. The valve stem 2 is installed in a fixed position, which can standardize the preload of the spring 7, thereby fixing the automatic adjustment amount of the gas ballast valve within the standard range, so that the gas ballast valve has a small range of overpressure load capacity, thereby ensuring the stability of the gas ballast amount and improving the accuracy of the gas volume scale.

[0030] This gas ballast valve is structurally equivalent to a regulating valve + transition chamber + flow restrictor + check valve. Firstly, it adjusts the gap length instead of the gap size, significantly increasing the adjustable distance and improving accuracy, ensuring stable gas ballast charging volume. Secondly, it replaces direct charging with two-stage charging; the external high-pressure medium does not directly charge the pump chamber, but instead charges it through the transition chamber. The external high-pressure medium replenishes the transition chamber through the regulating valve gap. Adjusting the gas ballast charging volume is equivalent to adjusting the pressure in the transition chamber. This gas ballast valve significantly reduces the gas pressure ratio between the external high-pressure medium and the transition chamber, to only tens to hundreds of times. During charging, the gas volume expands proportionally, amplifying even small changes in the gas ballast charging volume, but still far less than in a typical gas ballast valve. This reduces the difficulty of adjusting the gas ballast valve's charging volume by tens, hundreds, or even hundreds of times.

[0031] This invention controls the gas ballast volume by adjusting the gap length to control the gap conductance. The adjustment method is simple, reliable, and has good stability, making it less prone to jamming. Furthermore, adjustment is achieved by manually rotating the threaded adjusting seat 1, allowing for a long adjustment distance, precise adjustment, and more regular flow conductance changes, enabling linear control. The inflation volume scale 8 converts the height indication into a standard gas ballast inflation volume indication, achieving quantifiable gas ballast volume indication. The guide slope 31 on the valve core 3 improves the contact effect at the outer end of the valve plate 4, thereby improving the sealing effect of the valve plate 4 and reducing gas backflow. The valve plate 4 adopts a composite structure of rubber 41 and metal spring sheet 42. The metal spring plate 42 provides elasticity and maintains the overall shape, while the rubber 41 provides a sealing function, which can extend the service life of the valve plate 4 and ensure high stability. When the pressure difference between the upper and lower sides of the valve core 3 (the lower side of the valve core 3 is the pump chamber pressure) is greater than the elasticity of the spring 7, the valve core 3 will move upward under the high pressure of the pump chamber, the spring 7 will be compressed, reducing the preload of the valve plate 4 and increasing the reset distance of the valve plate 4, thereby increasing the single opening time of the gas ballast valve and automatically increasing the gas ballast charging volume. This achieves the effect of automatically adjusting the charging volume according to the change of the vacuum pump inlet pressure, which is beneficial to improving the gas ballast effect and the effective pumping speed of the vacuum pump. The limiting step 21 located above the valve plate 4 and the cone-shaped surface of the base 5 located below the valve plate 4 limit the maximum deformation of the valve plate 4 in an upward disc shape, avoiding plastic deformation due to exceeding the elastic deformation range of the metal spring plate 42, stabilizing the valve plate preload under standard conditions, and improving valve stability.

[0032] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0033] Although this document frequently uses terms such as adjusting seat 1; transition cavity 101; buffer groove 102; hexagonal inner hole 103; set screw 104; valve stem 2; limiting step 21; valve core 3; guide slope 31; limiting groove 32; vent hole 33; valve plate 4; rubber 41; metal spring plate 42; base 5; limiting slot 51; small hole 52; valve body 6; air inlet 61; gap 62; annular groove 63; slope 64; spring 7; inflation scale 8; first sealing ring 9; second sealing ring 10; locking nut 11; pressure gauge 12, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

[0034] Contents not described in detail herein are existing technologies known to those skilled in the art. The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A gas ballast valve with manual adjustment function, comprising a valve body (6), wherein an air inlet (61) is provided on the side of the valve body (6), characterized in that... It also includes an adjustment seat (1), which is threadedly installed at the end opening of the valve body (6). The bottom of the adjustment seat (1) is located below the air inlet (61). A gap (62) is formed between the outer wall of the adjustment seat (1) and the inner circumferential surface of the valve body (6). The gap (62) communicates with the air inlet (61). The gas introduced into the air inlet (61) enters the pump chamber after passing through the gap (62). The length of the gap (62) can be adjusted by manually rotating the adjustment seat (1).

2. A gas ballast valve with manual adjustment function according to claim 1, characterized in that... The valve body (6) is provided with an inflation scale (8) on its side. The top surface of the adjustment seat (1) is close to the inflation scale (8). The scale on the inflation scale (8) is the standard inflation volume corresponding to different gap (62) lengths.

3. A gas ballast valve with manual adjustment function according to claim 1, characterized in that... The valve body (6) has an annular groove (63) on its inner circumferential surface. The annular groove (63) is connected to the air inlet (61). An annular channel is formed between the annular groove (63) and the outer wall of the adjusting seat (1). The bottom of the annular channel is connected to the gap (62) through a slope (64).

4. A gas ballast valve with manual adjustment function according to claim 1, characterized in that... The top of the adjusting seat (1) has a hexagonal inner hole (103).

5. A gas ballast valve with manual adjustment function according to claim 1, characterized in that... The top side of the adjusting seat (1) is provided with a flange, and a set screw (104) is provided on the flange. By rotating the set screw (104), the bottom of the set screw (104) contacts the top surface of the valve body (6), thereby locking the valve body (6).

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