A pump oil discharge prevention type gas damper device for a rotary vane vacuum pump

Abstract

The utility model provides a kind of for vane vacuum pump's prevent pump oil discharge type air stand device, belong to vacuum obtaining equipment field, it solves the problem of pump oil leakage caused by the operation of traditional air stand structure under high vacuum state.The utility model includes connecting support, connecting support is equipped with mounting hole, air hole is equipped between mounting hole and connecting support, air hole is connected with the mounting hole installation air stand spring, PP ball is installed above air stand spring, PP ball upper contact air stand valve core, air stand knob is installed above air stand valve core, annular gap is formed between air stand knob and mounting hole, air stand valve core is equipped with inner concave spherical surface.The utility model has the advantages that: by PP ball and inner concave spherical surface cooperate and seal air stand valve core, when air hole exhausts to air stand knob, air stand spring and the gas blown by air hole push PP ball to air stand valve core, so that the inner concave spherical surface of air stand valve core and PP ball are closely contacted, reach the effect of preventing pump oil from flowing out from air stand valve when pump starts or exhaust pressure rises suddenly.

Description

Technical Field

[0001] This utility model belongs to the field of vacuum generation equipment technology, specifically relating to a gas ballast device for a rotary vane vacuum pump, and more particularly to a unidirectional gas ballast structure that combines gas introduction function and pump oil isolation function. Background Technology

[0002] Currently, rotary vane vacuum pumps generally use gas ballast devices to introduce an appropriate amount of air, reducing the saturation partial pressure of condensable vapors in the pump chamber and preventing them from condensing back into the pump oil and causing emulsification or contamination.

[0003] Traditional gas ballast structures are mostly simple throttling orifices or manually regulating valves, which only control the intake air volume and lack unidirectional conduction capability. When the pump is operating under high vacuum, the pressure in the exhaust chamber is much lower than atmospheric pressure, which can easily cause "backflow" through the gas ballast channel, drawing pump oil from the exhaust port into the gas ballast channel and causing it to overflow. At the initial stage of pump startup or during a sudden increase in exhaust pressure, the instantaneous positive pressure in the exhaust chamber may push the pump oil out along the gas ballast channel, leading to oil leakage, environmental pollution, and reduced pump oil life. In addition, conventional gas ballast valves lack a reliable sealing mechanism. The rubber valve core is prone to sealing failure due to long-term pressure deformation, unstable PP ball positioning, and spring fatigue failure, resulting in a significant decrease in airtightness over time. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by providing a gas ballast device for preventing pump oil discharge from a vacuum pump.

[0005] This utility model can be achieved through the following technical solution: a gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump, comprising a connecting bracket, an installation hole on the connecting bracket, a vent hole between the installation hole and the pump body, a gas ballast spring installed at the connection between the vent hole and the installation hole, a PP ball installed above the gas ballast spring, a gas ballast valve core in contact above the PP ball, a gas ballast knob installed above the gas ballast valve core, and an annular gap formed between the gas ballast knob and the installation hole.

[0006] In the above-mentioned anti-pump oil discharge type gas ballast device for rotary vane vacuum pumps, a sealing groove is provided at the bottom of the gas ballast knob, a sealing ring is installed in the sealing groove, the sealing ring is in contact with the gas ballast knob, and the gas ballast knob extends with a threaded section.

[0007] In the above-mentioned anti-pump oil discharge type gas ballast device for rotary vane vacuum pumps, the gas ballast valve core is provided with a concave spherical surface.

[0008] In the aforementioned gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump, the free length of the gas ballast spring is 12-13 mm, the pre-compression is 3.5-4.5 mm, and the corresponding preload is 0.85 N ± 0.05 N.

[0009] In the aforementioned gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump, the PP ball is made of polypropylene with a Shore hardness of A55±3 and a surface roughness Ra≤0.025μm.

[0010] Compared with the prior art, the advantages of this utility model are as follows: the gas ballast valve core is sealed by the mating surface between the PP ball and the concave spherical surface. When air enters the gas ballast knob, it facilitates air entry. When the vent hole exhausts gas to the gas ballast knob, the thrust of the gas ballast spring and the gas pressure blown out of the vent hole push the PP ball towards the gas ballast valve core, so that the concave spherical surface of the gas ballast valve core and the PP ball are in close contact, thereby preventing pump oil from flowing out of the gas ballast valve when the pump starts or the exhaust pressure rises suddenly. Attached Figure Description

[0011] Figure 1 This is an exploded diagram of a gas ballast device for preventing pump oil discharge in rotary vane vacuum pumps; Figure 2 This is a cross-sectional view of a gas ballast device for preventing pump oil discharge in rotary vane vacuum pumps; Figure 3 This is a cross-sectional view of the gas ballast knob of a gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump. Figure 4 This is a cross-sectional view of the gas ballast valve core of a gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump. Figure 5 This is a front view of the gas ballast spring in a gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump. Figure 6 yes Figure 2 Enlarged view within circle A; Among them, 1. connecting bracket; 11. mounting hole; 12. vent hole; 2. gas ballast spring; 3. PP ball; 4. gas ballast valve core; 41. concave spherical surface; 5. gas ballast knob; 51. sealing groove; 52. threaded section; 6. annular gap; 7. sealing ring. Detailed Implementation

[0012] 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.

[0013] like Figures 1 to 6As shown, this utility model can be implemented through the following embodiments: A gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump includes a connecting bracket 1, a mounting hole 11 on the connecting bracket 1, a vent hole 12 between the mounting hole 11 and the connecting bracket 1, a gas ballast spring 2 installed at the connection between the vent hole 12 and the mounting hole 11, a PP ball 3 installed above the gas ballast spring 2, a gas ballast valve core 4 in contact above the PP ball 3, a gas ballast knob 5 installed above the gas ballast valve core 4, and an annular gap 6 formed between the gas ballast knob 5 and the mounting hole 11.

[0014] Vent 12 connects to mounting hole 11 and connecting bracket 1, allowing air flowing in from gas ballast knob 5 to enter the vacuum pump and preventing liquefaction of gas inside the vacuum pump. Gas ballast knob 5 controls the opening and closing of the gas ballast structure and determines the amount of gas entering vent 12 based on the number of rotations. It has graduations on the top for adjustment. PP ball 3, in conjunction with gas ballast valve core 4, provides a one-way seal for the gas ballast structure, allowing airflow from gas ballast knob 5 to enter vent 12 and preventing liquefaction of gas inside the pump. The airflow at the vent hole 12 or the pump oil in the pump body leaks from the mounting hole 11; the gas ballast spring 2 is used to support the PP ball 3, so that while the PP ball 3 is in contact with the gas ballast valve core 4, a small gap is maintained between the PP ball 3 and the gas ballast valve core 4, allowing outside air to pass through the gas ballast valve core 4 and enter the vent hole 12; the annular gap 6 facilitates the introduction of airflow into the vent hole 12 after the gas ballast knob 5 is opened, preventing the gas ballast knob 5 from having too small a gap with the mounting hole 11, which would result in a small airflow and liquefaction of the compressed air.

[0015] like Figures 1 to 3 As shown, a sealing groove 51 is provided at the bottom of the gas ballast knob 5, and a sealing ring 7 is installed in the sealing groove 51. The sealing ring 7 contacts the gas ballast knob 5, and the gas ballast knob 5 extends with a threaded section 52. The sealing groove 51 and the sealing ring 7 are used to ensure the sealing performance of the gas ballast knob 5 when it is closed; and when the gas ballast knob 5 is opened, the sealing ring 7 and the sealing groove 51 form a dynamic seal. When outside air rushes into the mounting hole 11 due to the air pressure difference, the sealing ring 7 deforms, allowing airflow to flow into the mounting hole 11. At other times, the sealing ring 7 and the sealing groove 51 maintain the seal between the gas ballast knob 5 and the mounting hole 11. The threaded section 52 is used for the fixed connection between the gas ballast knob 5 and the mounting hole 11. There is a gap between the threaded section 52 and the mounting hole 11, allowing airflow to enter the mounting hole 11 through the gas ballast knob 5, and then enter the exhaust chamber through the vent hole 12.

[0016] like Figure 2 and Figure 4 As shown, the gas ballast valve core 4 is provided with a concave spherical surface 41. The concave spherical surface 41 is used to make close contact with the PP ball 3 when the vacuum pump is venting, so that the contact surface between the PP ball 3 and the gas ballast valve core 4 forms a sealing effect, preventing pump oil from leaking from the mounting hole 11 when the vacuum pump is venting.

[0017] like Figure 1 , Figure 2 and Figure 5 As shown, the free length of the gas ballast spring 2 is 12-13 mm, the pre-compression is 3.5-4.5 mm, and the corresponding preload is 0.85 N ± 0.05 N. The gas ballast spring 2 is used to push and support the PP ball 3 to contact the gas ballast valve core 4, ensuring that there is a slight gap between the gas ballast valve core 4 and the PP ball 3, so that the outside air can push the PP ball 3 open and enter the vent hole 12. When the vacuum pump exhausts, the high air pressure on one side of the vent hole 12 pushes the PP ball 3 to make tight contact with the concave spherical surface 41 of the gas ballast valve core 4, preventing pump oil from leaking from the mounting hole 11. The pre-compression causes the gas ballast spring 2 to generate a preload force, pushing the PP ball 3 to contact the gas ballast valve core 4.

[0018] like Figure 1 and Figure 2 As shown, the PP ball 3 is made of polypropylene with a Shore hardness of A55±3 and a surface roughness Ra≤0.025μm. Polypropylene is the thermoplastic resin with the lowest density, which makes the PP ball 3 lightweight. During vacuum pump exhaust, this allows for a rapid response of the one-way sealing structure, achieving a seal at the gas ballast valve core 4 when pump oil flows into the mounting hole 11 from the exhaust chamber. It is also heat-resistant and does not easily melt due to high temperatures. The Shore hardness of A55±3 allows the PP ball 3 to undergo slight deformation, facilitating its fit against the concave spherical surface 41 of the gas ballast valve core 4, enhancing sealing performance. The surface roughness Ra≤0.025μm reduces the generation of small pores during the process of the PP ball 3 tightly adhering to the gas ballast valve core 4, preventing pump oil leakage.

[0019] The working principle of this utility model is as follows: When the gas ballast knob 5 is opened according to the scale, when the external airflow rushes into the mounting hole 11, the airflow first passes through the annular gap 6. The sealing ring installed in the gas ballast knob 5 is deformed by the thrust generated by the pressure difference between the airflow and the vacuum in the vacuum pump, so that the airflow passes through and through the gap between the threaded section 52 and the mounting hole 11 to reach the gas ballast valve core 4. The airflow passes through the gas ballast valve core 4 and pushes the PP ball 3 to compress the gas ballast spring 2, and then enters the vent hole 12 through the gap between the gas ballast valve core 4 and the PP ball 3, and finally enters the exhaust chamber to prevent the gas in the exhaust chamber from liquefying.

[0020] When the vacuum pump starts to exhaust, the pressure inside the exhaust chamber increases. When the pressure inside the exhaust chamber is higher than the external atmospheric pressure, the air pressure in the exhaust chamber, together with the gas ballast spring 2, pushes the PP ball 3 to fit against the gas ballast valve core 4. The PP ball 3 fits tightly against the concave spherical surface 41 of the gas ballast valve core 4, and deforms due to its softness, further fitting against the concave spherical surface 41. This seals the contact surface between the gas ballast valve core 4 and the PP ball 3, preventing the pump oil flowing back from the exhaust chamber from leaking between the mounting hole 11 and the gas ballast knob 5, thus forming a one-way air intake gas ballast structure.

[0021] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model 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 this utility model or exceeding the scope defined by the appended claims.

[0022] Although this document uses a variety of terms, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

Claims

1. A gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump, comprising a connecting bracket (1), wherein the connecting bracket (1) has an installation hole (11), a vent hole (12) is provided between the installation hole (11) and the connecting bracket (1), a gas ballast spring (2) is installed at the connection between the vent hole (12) and the installation hole (11), a PP ball (3) is installed above the gas ballast spring (2), a gas ballast valve core (4) is in contact above the PP ball (3), a gas ballast knob (5) is installed above the gas ballast valve core (4), and an annular gap (6) is formed between the gas ballast knob (5) and the installation hole (11).

2. A gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump according to claim 1, characterized in that, The gas ballast knob (5) has a sealing groove (51) at its bottom, and a sealing ring (7) is installed in the sealing groove (51). The sealing ring (7) is in contact with the gas ballast knob (5), and the gas ballast knob (5) has a threaded section (52) extending from it.

3. A gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump according to claim 1, characterized in that, The gas ballast valve core (4) is provided with a concave spherical surface (41).

4. A gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump according to claim 1, characterized in that, The gas spring (2) has a free length of 12-13 mm, a pre-compression of 3.5-4.5 mm, and a corresponding preload of 0.85 N ± 0.05 N.

5. A gas ballast device for preventing pump oil discharge in a rotary vane vacuum pump according to claim 1, characterized in that, The PP ball (3) is made of polypropylene with a Shore hardness of A55±3 and a surface roughness Ra≤0.025μm.

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