Low-noise roots vacuum pump

Abstract

The utility model relates to the field of Roots vacuum pumps, in particular to a low-noise Roots vacuum pump. The technical problem to be solved by the utility model is to provide the low-noise roots vacuum pump which can carry out multi-stage noise reduction treatment on airflow noise generated in an exhaust process and realize sound energy absorption, vibration isolation and thermal noise control. A low-noise roots vacuum pump comprises a pump body. Two rotors which synchronously rotate in opposite directions are transversely arranged in the pump body; an air inlet is formed in the top of the pump body, an air outlet is formed in the bottom of the pump body, and a hush pipe used for eliminating exhaust noise is fixedly connected to the air outlet in the bottom of the pump body; the silencing pipe comprises a main pipe body; the two ends of the main pipe body are sleeved with connecting discs respectively. According to the utility model, airflow noise generated in the exhaust process is subjected to multi-stage noise reduction treatment, and the effects of sound energy absorption, vibration isolation and thermal noise control are realized.

Description

Technical Field

[0001] This utility model relates to the field of Roots vacuum pumps, and more particularly to a low-noise Roots vacuum pump. Background Technology

[0002] Roots vacuum pumps are widely used in high-efficiency gas delivery applications in semiconductor, chemical, and pharmaceutical industries due to their compact structure, high pumping speed, and oil-free operation. However, the high-frequency airflow pulsation generated by the periodic exhaust of the rotor during their operation causes significant aerodynamic noise, especially at the exhaust port where the sound pressure level can exceed 100dB. This severely restricts the application of the equipment in noise-sensitive environments such as laboratories and medical facilities. Traditional noise reduction solutions often use external silencers or soundproof enclosures, but these suffer from problems such as large size, increased airflow resistance, and inconvenient maintenance. While conventional water-cooling structures can reduce exhaust temperature, their effect on suppressing broadband noise is limited. Therefore, there is an urgent need to develop a low-noise Roots vacuum pump that can perform multi-stage noise reduction treatment on the airflow noise generated during the exhaust process, achieving sound energy absorption, vibration isolation, and thermal noise control. Utility Model Content

[0003] To overcome the shortcomings of traditional noise reduction solutions that often employ external silencers or soundproof enclosures, which suffer from large size, increased airflow resistance, and inconvenient maintenance, and the limited effectiveness of conventional water-cooled structures in suppressing broadband noise, this invention aims to provide a low-noise Roots vacuum pump capable of multi-stage noise reduction for airflow noise generated during exhaust: achieving sound energy absorption, vibration isolation, and thermal noise control.

[0004] This utility model is achieved by the following specific technical means:

[0005] A low-noise Roots vacuum pump includes a pump body; two counter-rotating synchronous rotors are arranged laterally inside the pump body; an air inlet is provided at the top of the pump body, and an air outlet is provided at the bottom of the pump body;

[0006] A silencer pipe for eliminating exhaust noise is fixedly connected to the exhaust port at the bottom of the pump body. The silencer pipe includes a main body. Connecting discs are fitted at both ends of the main body. A sealing sleeve is also provided between the two connecting discs. A protruding shaft section is provided on the end face of the two connecting discs opposite to the sealing sleeve. The two ends of the sealing sleeve are respectively fitted onto the protruding shaft ends of the two connecting discs, so that an annular cavity is formed between the inner diameter surface of the sealing sleeve and the outer diameter surface of the main body. Limiting rings are also fixedly connected to both ends of the main body by bolts. The outer diameter of the limiting rings is larger than the outer diameter of the main body, which limits the two connecting discs and the sealing sleeve that mates with the connecting discs. A shock-absorbing rubber layer is provided on the outer diameter surface of the main body and the limiting rings that contact the connecting discs. A water inlet hole communicating with the cavity is provided on the connecting disc at one end of the main body. A water outlet hole communicating with the cavity is also provided on the connecting disc at the other end of the main body. A vacuum tube is also fitted on the outer diameter surface of the sealing sleeve.

[0007] Furthermore, the vacuum tube includes an inner tube; an outer tube disposed outside the inner tube; side caps connected to both ends of the inner tube and the outer tube; a vacuum cavity is formed between the outer diameter surface of the inner tube and the inner diameter surface of the outer tube, and an air nozzle for extracting air from the vacuum cavity is fixedly connected to the outer diameter surface of the outer tube.

[0008] Furthermore, a shock-absorbing and sound-insulating layer is provided between the inner diameter surface of the inner tube of the vacuum tube and the outer diameter surface of the sealing sleeve; this improves the shock-absorbing and sound-insulating effect and further reduces noise.

[0009] Furthermore, a sound-absorbing inner layer is also provided on the inner diameter surface of the main tube; the sound-absorbing inner layer further improves the vibration reduction and sound insulation effect and reduces noise.

[0010] Furthermore, a sealing ring is provided at the connection point where the inner diameter surface of the sealing sleeve mates with the protruding shaft end of the connecting disc to prevent cooling water leakage from the annular cavity.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] This invention achieves multi-level noise reduction for airflow noise generated during exhaust: realizing the effects of sound energy absorption, vibration isolation, and thermal noise control. Attached Figure Description

[0013] Figure 1 This is a partial cross-sectional view of the present invention.

[0014] Figure 2 This is a cross-sectional view of the silencer pipe of this utility model.

[0015] Figure 3 This is a partial cross-sectional view of the silencer pipe of this utility model.

[0016] Figure 4This is a cross-sectional view of the vacuum tube structure of this utility model.

[0017] The labels in the attached diagram are as follows: 1-Pump body, 2-Rotor, 3-Air inlet, 4-Air outlet, 5-Silencer pipe, 51-Main body, 52-Limiting ring, 53-Connecting disc, 54-Sealing sleeve, 55-Shock-absorbing rubber layer, 56-Water inlet, 57-Water outlet, 58-Shock-absorbing and sound-insulating layer, 59-Vacuum tube, 510-Silencer inner layer, 591-Inner tube, 592-Outer tube, 593-Side cover, 594-Air nozzle. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings: Example

[0019] A low-noise Roots vacuum pump, such as Figure 1-4 As shown, it includes a pump body 1; two rotors 2 rotating synchronously in opposite directions are arranged horizontally inside the pump body 1; an air inlet 3 is provided at the top of the pump body 1, and an air outlet 4 is provided at the bottom of the pump body 1.

[0020] A silencer pipe 5 for eliminating exhaust noise is fixedly connected to the exhaust port 4 at the bottom of the pump body 1; the silencer pipe 5 includes a main body 51; connecting discs 53 are respectively sleeved at both ends of the main body 51; a sealing sleeve 54 is also provided between the two connecting discs 53, and a protruding shaft section is provided on the end face of the two connecting discs 53 opposite to the sealing sleeve 54. The two ends of the sealing sleeve 54 are respectively sleeved on the protruding shaft ends of the two connecting discs 53, so that an annular cavity is formed between the inner diameter surface of the sealing sleeve 54 and the outer diameter surface of the main body 51; the two ends of the main body 51 are open to A limiting ring 52 is also fixedly connected by bolts. The outer diameter of the limiting ring 52 is larger than the outer diameter of the main body 51, which limits the two connecting discs 53 and the sealing sleeve 54 that mates with the connecting discs 53. A shock-absorbing rubber layer 55 is provided on the outer diameter surface of the main body 51 and the limiting ring 52 that contacts the connecting discs 53. A water inlet hole 56 communicating with the cavity is provided on the connecting disc 53 at one end of the main body 51. A water outlet hole 57 communicating with the cavity is also provided on the connecting disc 53 at the other end of the main body 51. A vacuum tube 59 is also fitted on the outer diameter surface of the sealing sleeve 54.

[0021] The vacuum tube 59 includes an inner tube 591; an outer tube 592 disposed outside the inner tube 591; side caps 593 connected to both ends of the inner tube 591 and the outer tube 592; a vacuum cavity is formed between the outer diameter surface of the inner tube 591 and the inner diameter surface of the outer tube 592, and an air nozzle 594 for extracting air from the vacuum cavity is fixedly connected to the outer diameter surface of the outer tube 592.

[0022] Working principle:

[0023] When this low-noise Roots vacuum pump is working, the motor drives two rotors 2 inside the pump body 1 to rotate synchronously in opposite directions, creating a negative pressure at the top air inlet 3 to draw in gas. After being compressed by the rotors 2, the gas is discharged from the bottom exhaust outlet 4. To significantly reduce exhaust noise, a silencer pipe 5 with a multi-stage silencing structure is connected to the exhaust outlet 4: the discharged airflow first enters the main body 51 of the silencer pipe 5, where the inner silencing layer 510 absorbs some of the sound energy, performing initial sound absorption; simultaneously, cooling water flows through the water inlet 56 on the connecting plate 53 into the annular cavity formed by the outer wall of the main body 51 and the inner wall of the sealing sleeve 54 for circulation. The exhaust temperature is reduced by cooling, thus reducing thermal expansion noise, while the water flow absorbs the sound wave energy. A vacuum tube 59 is fitted on the outside of the sealing sleeve 54. The vacuum cavity between the inner tube 591 and the outer tube 592 is formed by evacuating the air nozzle 594, effectively isolating noise transmission. The vibration damping and sound insulation layer 58 between the inner tube 591 and the sealing sleeve 54 further absorbs vibration and residual sound waves. The entire noise reduction structure is firmly connected by the connecting plate 53, the limiting ring 52 and the bolts. The vibration damping rubber layer 55 reduces vibration transmission, and the sealing ring ensures the sealing of the cooling cavity, thereby achieving efficient multi-stage noise reduction.

[0024] Although this disclosure has been described in detail with reference to exemplary embodiments, it is not limited thereto, and it will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the scope of this disclosure.

Claims

1. A low-noise Roots vacuum pump, comprising a pump body (1); two rotors (2) rotating synchronously in opposite directions are arranged laterally inside the pump body (1); an air inlet (3) is provided at the top of the pump body (1), and an air outlet (4) is provided at the bottom of the pump body (1). Its features are, A silencer pipe (5) for eliminating exhaust noise is fixedly connected to the bottom exhaust port (4) of the pump body (1); the silencer pipe (5) includes a main body (51); connecting discs (53) are respectively fitted at both ends of the main body (51); a sealing sleeve (54) is also provided between the two connecting discs (53), and a protruding shaft section is provided on the end face of the two connecting discs (53) opposite to the sealing sleeve (54). The two ends of the sealing sleeve (54) are respectively fitted onto the protruding shaft ends of the two connecting discs (53), so that an annular cavity is formed between the inner diameter surface of the sealing sleeve (54) and the outer diameter surface of the main body (51); the two ends of the main body (51) are connected by screws The bolt is also fixedly connected to a limiting ring (52), the outer diameter of which is larger than that of the main body (51), limiting the two connecting discs (53) and the sealing sleeve (54) that mates with the connecting discs (53); and a shock-absorbing rubber layer (55) is provided on the outer diameter surface of the main body (51) and the limiting ring (52) that contacts the connecting disc (53); a water inlet hole (56) communicating with the cavity is provided on the connecting disc (53) at one end of the main body (51); a water outlet hole (57) communicating with the cavity is also provided on the connecting disc (53) at the other end of the main body (51); and a vacuum tube (59) is also fitted on the outer diameter surface of the sealing sleeve (54).

2. The low-noise Roots vacuum pump according to claim 1, characterized in that, The vacuum tube (59) includes an inner tube (591); an outer tube (592) disposed outside the inner tube (591); and side caps (593) connected to both ends of the inner tube (591) and the outer tube (592). A vacuum cavity is formed between the outer diameter surface of the inner tube (591) and the inner diameter surface of the outer tube (592), and an air nozzle (594) for extracting air from the vacuum cavity is fixedly connected to the outer diameter surface of the outer tube (592).

3. A low-noise Roots vacuum pump according to claim 2, characterized in that, A shock-absorbing and sound-insulating layer (58) is also provided between the inner diameter surface of the inner tube (591) of the vacuum tube (59) and the outer diameter surface of the sealing sleeve (54).

4. A low-noise Roots vacuum pump according to claim 1, characterized in that, The inner diameter surface of the main body (51) is also provided with a sound-absorbing inner layer (510).

5. A low-noise Roots vacuum pump according to claim 1, characterized in that, The inner diameter surface of the sealing sleeve (54) is fitted with the protruding shaft end of the connecting disc (53), and a rubber sealing ring is provided at the connection point.

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