Silencer for an electronic vacuum pump

Abstract

This utility model discloses a noise reduction device for an electronic vacuum pump, relating to the field of vacuum pump technology. It includes an electronic vacuum pump and a noise reduction device, comprising a noise reduction sleeve and a protective cover. The noise reduction sleeve is tubular, with at least two inner sleeves inside. Each inner sleeve has a sound outlet at its top. An outer cavity is formed between the protective cover and the noise reduction sleeve, and the outer cavity and the inner cavities of the inner sleeves are connected through the sound outlet. When gas enters the outer cavity from the inner cavity, the sudden expansion of the space reduces the airflow velocity, decreasing turbulent noise generated by friction between the high-speed airflow and the wall. The outer cavity acts as a "buffer cavity," balancing gas pressure fluctuations and preventing impact noise caused by sudden pressure changes. The gas flows in a tortuous path through multiple cavities, increasing the path length. Friction and viscous resistance against the cavity walls during the flow consume some of the gas kinetic energy, indirectly reducing the energy of the noise source. Sound waves are absorbed by the noise reduction sleeve and inner sleeves during multiple reflections and cancel each other out after multiple interferences, significantly reducing the noise level.

Description

Technical Field

[0001] This utility model belongs to the field of vacuum pump technology, and specifically relates to an electronic vacuum pump silencing device. Background Technology

[0002] As a key component in fields such as new energy vehicles and medical equipment, electronic vacuum pumps generate high-frequency noise due to high-speed gas turbulence and mechanical vibration during operation, which has become a significant issue affecting the user experience. Existing noise reduction devices generally suffer from limitations in noise reduction effectiveness and insufficient adaptability, making it difficult to meet the requirements of highly quiet environments.

[0003] Traditional silencing structures often employ a single-cavity design, achieving only simple buffering by increasing volume, which has limited effectiveness in suppressing mid-to-high frequency turbulent noise. Some devices rely on sound-absorbing materials for filling, but with long-term use, the material is prone to shedding due to airflow impact, not only reducing silencing performance but also potentially blocking air passages and affecting pump efficiency.

[0004] Furthermore, existing technologies struggle to meet the demands of wide-band noise reduction: single resonant cavity designs can only address noise at specific frequencies, resulting in poor adaptability to the dynamically changing noise spectrum during vacuum pump operation; while simplified straight-through structures, although ensuring smooth exhaust flow, cannot effectively address low-frequency humming caused by pressure fluctuations. Simultaneously, most silencing devices fail to optimize airflow paths, leading to secondary turbulence within the cavity from high-speed airflow, which in turn generates new noise sources, hindering the overall improvement in noise reduction performance. Utility Model Content

[0005] In view of the problems mentioned in the background art, the purpose of this utility model is to provide an electronic vacuum pump silencing device to solve the problems mentioned in the background art.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0007] An electronic vacuum pump silencing device includes an electronic vacuum pump and a silencing device. The silencing device includes a silencing sleeve and a protective cover. The silencing sleeve is tubular and has at least two inner sleeves. The top of the inner sleeve has a sound outlet. An outer cavity is formed between the protective cover and the silencing sleeve. The outer cavity and the inner cavity of the inner sleeve are connected through the sound outlet.

[0008] Preferably, the electronic vacuum pump includes a cover plate with at least two sets of second vent holes, and a sound-absorbing sleeve is installed between the protective cover and the cover plate, with the second vent holes all located within the inner sleeve.

[0009] Preferably, the inner wall of the protective cover is provided with a groove, the silencing sleeve is snapped into the groove, one side of the groove is recessed inward, forming an overflow port between the groove and the silencing sleeve, and the outer cavity, the cavity between the outer wall of the silencing sleeve and the protective cover are connected to the air outlet through the overflow port.

[0010] Preferably, the electronic vacuum pump includes a pump body and a pump base, with the pump body installed between the cover plate and the pump base. The pump body is tubular and has a pump core and scraper installed in the middle pump chamber.

[0011] Preferably, the pump chamber is connected to the inner cavity through a second vent.

[0012] Preferably, a first vent hole is provided on the pump base, and the pump chamber is connected to the air inlet of the electronic vacuum pump through the first vent hole.

[0013] Preferably, the pump chamber of the central hole of the pump body is elliptical.

[0014] Preferably, the inner sleeve is in the shape of an inverted cup, and the sound outlet is opened at the top of the inner sleeve along the central axis of the inner sleeve.

[0015] This invention proposes an electronic vacuum pump silencing device. When gas enters the outer cavity from the inner cavity, the sudden expansion of the space reduces the airflow velocity (Bernoulli's principle), decreasing turbulent noise generated by friction between the high-speed airflow and the wall. The outer cavity acts as a "buffer cavity," balancing gas pressure fluctuations and preventing impact noise caused by sudden pressure changes. The gas flows in a tortuous path through multiple cavities, increasing the path length. Friction and viscous resistance against the cavity walls during flow consume some of the gas's kinetic energy, indirectly reducing the energy of the noise source. Sound waves are absorbed by the silencing sleeve and inner sleeve during multiple reflections and cancel each other out after multiple interferences, significantly reducing noise levels. This device has a simple structure and excellent noise reduction effect.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of an electronic vacuum pump silencing device proposed in this utility model;

[0018] Figure 2 This is an exploded view of an electronic vacuum pump silencing device proposed in this utility model;

[0019] Figure 3 This is a front view of the electronic vacuum pump silencing device proposed in this utility model;

[0020] Figure 4 for Figure 3 A sectional perspective view along the AA direction;

[0021] Figure 5 for Figure 3 A sectional perspective view along the BB direction;

[0022] Figure 6 This is a top view of the electronic vacuum pump silencing device proposed in this utility model;

[0023] Figure 7 for Figure 6 A sectional perspective view along the CC direction;

[0024] Figure 8 This is a three-dimensional structural diagram of an electronic vacuum pump silencing device proposed in this utility model.

[0025] Reference numerals: 1. Motor assembly; 2. Pump base; 21. First vent; 3. Pump core; 4. Shock absorber; 5. Support sleeve; 6. Pump body; 7. Scraper; 8. Cover plate; 81. Second vent; 9. Irregular sealing ring; 10. Silencing sleeve; 101. Inner sleeve; 102. Inner cavity; 103. Outer cavity; 104. Sound outlet; 11. Protective cover; 12. Air inlet; 13. Air outlet. Detailed Implementation

[0026] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0027] Example 1

[0028] refer to Figures 1 to 8 The electronic vacuum pump silencing device described in this embodiment includes an electronic vacuum pump and a silencing device. The silencing device is installed on the electronic vacuum pump. The electronic vacuum pump includes a motor assembly 1, a pump base 2 is installed on the motor assembly 1, and a pump body 6 and a cover plate 8 are installed between the pump base 2 and the silencing device. The pump body 6 is tubular and is installed between the pump base 2 and the cover plate 8. The elliptical cavity of the pump body 6 is the pump chamber of a vane pump. A scraper 7 and a pump core 3 are installed in the pump chamber. The scraper 7 and the pump core 3 are installed on the output end of the motor assembly 1. The two ends of the motor assembly 1 are respectively connected to an air inlet 12 and an air outlet 13. A first vent hole 21 is opened on the pump base 2, and the air inlet 12 is connected to the cavity below the pump chamber 2.

[0029] A special-shaped sealing ring 9 is installed between the pump base 2 and the motor assembly 1 to ensure sealing.

[0030] The motor assembly 1 has support sleeves 5 installed at both ends, and shock-absorbing pads 4 are fitted on the support sleeves 5.

[0031] The silencing device includes a silencing sleeve 10 and a protective cover 11. The protective cover 11 is fitted onto the motor assembly 1. The pump base 2, pump body 6, and cover plate 8 are all located inside the protective cover 11. The silencing sleeve 10 is tubular, with its bottom end abutting against the cover plate 8. A groove 111 is provided on the inner wall of the protective cover 11, and the silencing sleeve 10 is snapped into the groove 111. At least two inner sleeves 101 are provided inside the silencing sleeve 10. A sound outlet 104 is opened at the top of the inner sleeve 101. An outer cavity 103 is formed between the protective cover 11 and the silencing sleeve 10. The outer cavity 103 and the inner sleeve 101 are connected. The inner cavity 102 of 01 is connected through the sound outlet 104. The slot 111 is recessed inward on one side, forming an overflow outlet 105 with the silencing sleeve 10. The cavity between the outer wall of the silencing sleeve 10 and the protective cover 11 is connected to the outer cavity 103 through the overflow outlet 105. The cavity between the outer wall of the silencing sleeve 10 and the protective cover 11 is connected to the air outlet 13 of the electronic vacuum pump. At least two sets of second vent holes 81 are provided on the cover plate 8. The second vent holes 81 are correspondingly opened within the range of the inner sleeve 101. The inner cavity 102 and the pump chamber are connected through the second vent holes 81.

[0032] The inner sleeve 101 is in the shape of an inverted cup, and the sound outlet 104 is opened at the top of the inner sleeve 101 along the central axis of the inner sleeve 101.

[0033] Preferably, this embodiment provides two inner sleeves 101, and the two sets of inner sleeves 101 are symmetrically arranged inside the silencer sleeve 10 to extend the gas flow path.

[0034] Preferably, both the silencer tube 10 and the inner sleeve 101 are made of rubber material.

[0035] Working principle: Gas enters the cavity at the bottom of the pump base 2 through the air inlet 12, enters the pump chamber (i.e., the cavity of the pump body 6) through the first vent 21, is compressed by the high-speed rotation of the pump core 3 and the scraper 7, and then enters the corresponding inner cavity 102 through the second vent 81. It then enters the outer cavity 103 through the sound outlet 104 on the inner tube 101, and then enters the cavity between the protective cover 11 and the silencer sleeve 10 through the overflow outlet 105. This cavity is connected to the air outlet 13, so it flows out from the air outlet 13.

[0036] When gas enters the outer cavity 103 from the inner cavity 102, the sudden expansion of the space reduces the airflow velocity (Bernoulli's principle), decreasing turbulent noise generated by friction between the high-speed airflow and the wall. The outer cavity 103 acts as a "buffer cavity," balancing gas pressure fluctuations and preventing impact noise caused by sudden pressure changes. The gas flows in a tortuous path through multiple cavities, increasing the path length. Friction and viscous resistance between the gas and the walls of the silencing sleeve 10 and the inner tube 101 during the flow consume some of the gas's kinetic energy, indirectly reducing the energy of the noise source. Sound waves are absorbed by the silencing sleeve 10 and the inner sleeve 101 during multiple reflections and cancel each other out after multiple interferences, significantly reducing the noise level. This device has a simple structure and excellent noise reduction effect.

[0037] It should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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.

[0038] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] 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, an electrical connection, or a connection that allows communication between them; 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.

[0040] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through 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. "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.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An electronic vacuum pump silencing device comprising an electronic vacuum pump and a silencing device, characterized in that: The silencing device includes a silencing sleeve (10) and a protective cover (11). The silencing sleeve (10) is tubular and has at least two inner sleeves (101). The top of the inner sleeve (101) is provided with a sound outlet (104). An outer cavity (103) is formed between the protective cover (11) and the silencing sleeve (10). The outer cavity (103) and the inner cavity (102) of the inner sleeve (101) are connected through the sound outlet (104).

2. The electronic vacuum pump silencing device according to claim 1, characterized in that: The electronic vacuum pump includes a cover plate (8), on which at least two sets of second vent holes (81) are provided. A silencer sleeve (10) is installed between the protective cover (11) and the cover plate (8), and the second vent holes (81) are located within the inner sleeve (101).

3. The electronic vacuum pump silencing device according to claim 2, characterized in that: The inner wall of the protective cover (11) is provided with a slot (111), and the silencing sleeve (10) is snapped into the slot (111). One side of the slot (111) is recessed inward, forming an overflow port (105) between it and the silencing sleeve (10). The outer cavity (103), the cavity between the outer wall of the silencing sleeve (10) and the protective cover (11) are connected to the air outlet (13) through the overflow port (105).

4. The electronic vacuum pump silencing device of claim 2, wherein: The electronic vacuum pump includes a pump body (6) and a pump base (2). The pump body (6) is installed between the cover plate (8) and the pump base (2). The pump body (6) is tubular and has a pump core (3) and a scraper (7) installed in the middle pump chamber.

5. The electronic vacuum pump silencing device according to claim 4, characterized in that: The pump chamber is connected to the inner cavity (102) through the second vent (81).

6. The electronic vacuum pump silencing device of claim 4, wherein: The pump base (2) is provided with a first vent hole (21), and the pump chamber is connected to the air inlet (12) of the electronic vacuum pump through the first vent hole (21).

7. The electronic vacuum pump silencing device of claim 4, wherein: The pump chamber of the central hole of the pump body (6) is elliptical.

8. The electronic vacuum pump silencing device of claim 7, wherein: The inner sleeve (101) is in the shape of an inverted cup, and the sound outlet (104) is opened at the top of the inner sleeve (101) along the central axis of the inner sleeve (101).

Images