Fan noise reduction device and sweeper

Abstract

This invention proposes a fan noise reduction device, comprising: a fan, the fan including a blade and a motor; an upper volute disposed at the top of the blade; a lower volute connected to the upper volute and enclosing the fan, the lower volute having a fundamental frequency filter hole penetrating through the lower volute; a motor disposed at the bottom of the lower volute and connected to the blade via a rotating shaft; and a first silencing cavity corresponding to the fundamental frequency filter hole on the side of the lower volute away from the blade. The blade rotates at high speed, and the surrounding medium generated by the rotation of the blade flows through the volute. When the airflow enters the fundamental frequency filter hole, it flows into the first silencing cavity. The resonant silencing structure of the first silencing cavity further filters the fundamental frequency, reducing the noise generated by the fundamental frequency filter.

Description

Technical Field

[0001] This field relates to the field of cleaning technology, and in particular to a fan noise reduction device and a sweeper. Background Technology

[0002] With the development of technology, sweeping machines have entered thousands of households to help people with cleaning tasks. However, when sweeping machines are running, the operation of the fan can generate considerable noise. Current technology mainly uses methods such as adjusting the fan blade shape, but this is often not very effective and affects the user experience. This technology has also gradually reached a bottleneck. Summary of the Invention

[0003] This invention provides a fan noise reduction device and a sweeper, aiming to solve the technical problem of excessive noise generated by the fan when the sweeper is performing cleaning tasks.

[0004] To achieve the above-mentioned objectives, the present invention proposes a fan noise reduction device, comprising:

[0005] The fan includes fan blades and a motor;

[0006] Upper volute, wherein the upper volute is disposed at the top of the fan blade;

[0007] The lower volute is connected to the upper volute and encloses the fan. The lower volute is provided with a base frequency filter hole that penetrates through the lower volute.

[0008] The motor is located at the bottom of the lower volute and is connected to the fan blade via a rotating shaft;

[0009] The lower volute is provided with a first noise-absorbing cavity corresponding to the fundamental frequency filter hole on the side away from the fan blade.

[0010] Furthermore, it also includes: a sound-absorbing cover plate, on which a first side wall and a second side wall are vertically arranged, the first side wall and the second side wall are spaced apart, and a sound-absorbing channel is also formed on the side of the lower volute away from the fan blade;

[0011] The silencing cover is disposed at the bottom of the lower volute. The ends of the first sidewall and the second sidewall away from the silencing cover contact the bottom of the lower volute and are engaged in the silencing channel. The silencing cover, the first sidewall, the second sidewall, and the sidewall of the silencing channel together form a first silencing cavity.

[0012] Furthermore, it also includes: a volute tongue, which is disposed at the air outlet of the lower volute, and the base frequency filter hole is disposed in the area near the air outlet.

[0013] Furthermore, the fundamental frequency filter frequency is equal to the fundamental frequency of the fan, and the fundamental frequency filter frequency satisfies the formula: f0=c / 2*pi*((pi*r2) / V / (t+1.6r))0.5, and the fundamental frequency of the fan is: f1=n*z / 60; where c is the sound speed of the airflow, n is the fan speed, z is the number of fan blades, V is the volume of the first silencing cavity, r is the radius of the fundamental frequency filter hole, t is the thickness of the volute, and pi is pi.

[0014] Furthermore, it also includes: a wideband filter hole, wherein the lower volute is provided with the wideband filter hole; and a second noise-absorbing cavity corresponding to the wideband filter hole is provided on the outer side of the lower volute.

[0015] Furthermore, several of the aforementioned broadband filter holes are evenly distributed on the lower volute.

[0016] Furthermore, it also includes: a first sound-absorbing cotton, which seals the outer side of the first sound-absorbing cavity and the space between the lower volute and the sound-absorbing cover plate, wherein the first sound-absorbing cotton is disposed below the broadband filter hole and fills the second sound-absorbing cavity.

[0017] Furthermore, a second sound-absorbing cotton is provided in the first sound-absorbing cavity, and the second sound-absorbing cotton is located at the opening of the fundamental frequency filter hole; a certain space is left between the second sound-absorbing cotton and the sound-absorbing cover plate in the first sound-absorbing cavity, and the volume of the space is the volume of the first sound-absorbing cavity.

[0018] Furthermore, the upper volute and the lower volute are connected by a snap-fit ​​connection.

[0019] A sweeper according to a second aspect of the present invention includes a fan noise reduction device according to the first aspect of the present invention described above.

[0020] According to the embodiments of the present invention, at least the following technical effects are achieved: the fan blades rotate at high speed and the surrounding medium generates airflow that flows inside the volute. When the airflow flows into the fundamental frequency filter hole, it flows into the first silencing cavity through the fundamental frequency filter hole. The fundamental frequency filter is then filtered through the resonant silencing structure of the first silencing cavity, thereby reducing the noise generated by the fundamental frequency filter. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a fan noise reduction device according to an embodiment of the present invention;

[0022] Figure 2 This is a cross-sectional view of a fan noise reduction device according to another embodiment of the present invention;

[0023] Figure 3 This is an exploded view of a fan noise reduction device according to an embodiment of the present invention;

[0024] Figure 4 This is a cross-sectional view of a fan noise reduction device according to an embodiment of the present invention;

[0025] Among them, the fan blade is 110, the motor is 120, the upper volute is 200, the lower volute is 300, the volute tongue is 310, the base frequency filter hole is 320, the broadband filter hole is 330, the sound-absorbing cover plate is 400, the first side wall is 410, the second side wall is 420, the first sound-absorbing cotton is 500, and the first sound-absorbing cavity is 600.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals 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 the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, 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," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention 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, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] This invention proposes a fan noise reduction device, comprising: a fan, the fan including a fan blade 110 and a motor 120; an upper volute 200 disposed at the top of the fan blade 110; a lower volute 300 connected to the upper volute 200 and enclosing the fan, the lower volute 300 having a fundamental frequency filter hole 320 penetrating through the lower volute 300; the motor 120 disposed at the bottom of the lower volute 300, the motor 120 being connected to the fan blade 110 via a rotating shaft; and a first silencing cavity 600 corresponding to the fundamental frequency filter hole 320 disposed on the side of the lower volute 300 away from the fan blade 110.

[0032] Reference Figure 1-3 Specifically, the fan includes a fan blade 110 and a motor 120. An upper volute 200 is placed above the fan blade 110, and a lower volute 300 surrounds the fan blade 110 within the gap between the upper and lower volutes 200. A fundamental frequency filter hole 320 is provided on the volute, penetrating the lower volute 300. At the location of the fundamental frequency filter hole 320, a corresponding first silencing cavity 600 is provided on the outer side of the lower volute 300, allowing the first silencing cavity 600 to communicate with the lower volute 300 through the fundamental frequency filter hole 320. The motor 120 is located at the bottom of the lower volute 300, and the motor 120 is connected to the fan blade 110 via a rotating shaft, causing the fan blade 110 to rotate. In other embodiments of the invention, the fundamental frequency filter holes 320 provided at the upper end of the silencing cavity can be two, three, etc. The fundamental frequency filter holes 320 in the lower volute 300 ensure normal pressurization of the fan. When the sweeper is working, the fan blades 110 rotate at high speed, and the fan blades 110 simultaneously rotate the surrounding medium to generate airflow inside the volute. When the airflow flows into the fundamental frequency filter hole 320, which is connected to the first silencing cavity 600, the airflow enters the first silencing cavity 600 and is filtered by the resonant silencing structure of the first silencing cavity 600, thereby reducing the noise generated by the fundamental frequency filter. The connection between the first silencing cavity 600 and the fundamental frequency filter hole 320 reduces the noise generated by the fundamental frequency filter during sweeper cleaning, minimizing the noise impact on the user.

[0033] In some embodiments of the present invention, it further includes: a sound-absorbing cover plate 400, on which a first sidewall 410 and a second sidewall 420 are vertically arranged, the first sidewall 410 and the second sidewall 420 are spaced apart, and a sound-absorbing channel is also formed on the side of the lower volute 300 away from the fan blade;

[0034] The silencing cover plate 400 is disposed at the bottom of the lower volute 300. The ends of the first sidewall 410 and the second sidewall 420 away from the silencing cover plate 400 contact the bottom of the lower volute 300 and are engaged in the silencing channel. The silencing cover plate 400, the first sidewall 410, the second sidewall 420, and the sidewall of the silencing channel together form a first silencing cavity 600.

[0035] Reference Figure 2-4 The muffler cover 400 is located at the bottom of the lower volute 300 and is connected to the lower volute 300. The muffler cover 400 is placed horizontally, and has a vertically arranged first sidewall 410 and second sidewall 420 in the upward direction. There is a certain distance between the first sidewall 410 and the second sidewall 420, and the first sidewall 410 and the second sidewall 420 are parallel. The upper surfaces of the first sidewall 410 and the second sidewall 420 abut against the lower volute 300, and a hollow muffler channel is formed on the side of the lower volute 300 away from the fan blade 110. A noise-absorbing cover 400 is disposed at the bottom of the lower volute 300. The ends of the first sidewall 410 and the second sidewall 420 away from the noise-absorbing cover 400 contact the bottom of the lower volute 300 and are engaged in the noise-absorbing channel. The noise-absorbing cover 400, the first sidewall 410, the second sidewall 420, and the sidewalls of the noise-absorbing channel together form a first noise-absorbing cavity 600. The noise-absorbing cavity is formed by the connection between the noise-absorbing cover 400 and the lower volute 300, thereby improving the noise generated by the fundamental frequency filter and reducing the noise impact on the user. The noise-absorbing cover 400 has a snap-fit ​​structure, which forms an initial connection with the lower volute 300.

[0036] In some embodiments of the present invention, it further includes: a volute tongue 310, the volute tongue 310 being disposed at the air outlet of the lower volute 300, and the base frequency filter hole 320 being disposed in the region near the air outlet.

[0037] The volute tongue 310 is the junction of the air outlet and air inlet of the volute. The airflow at the volute tongue 310 is complex, and the distance between the volute tongue 310 and the fan blade 110 is the smallest, resulting in the largest noise from the fundamental frequency filter. The fundamental frequency filter hole 320 is designed near the volute tongue 310, which can improve the noise of the fundamental frequency filter to the greatest extent and improve the noise reduction of the fan.

[0038] In some embodiments of the present invention, the fundamental frequency filter frequency is equal to the fundamental frequency of the wind turbine.

[0039] The fundamental frequency of the fundamental frequency filter is related to the fundamental frequency of the fan. Preferably, when the fundamental frequency filter frequency is equal to the fundamental frequency of the fan, the noise of the sweeper's fundamental frequency filter will be reduced to the minimum, thereby improving the fan noise quality of the sweeper and enhancing the user experience.

[0040] In some embodiments of the present invention, the fundamental frequency filtering frequency satisfies the formula, f0=c / 2*pi*((pi*r 2 ) / V / (t+1.6r)) 0.5 The fundamental frequency of the fan is: f1=n*z / 60; where c is the speed of sound of the airflow, n is the fan speed, z is the number of blades, V is the volume of the first silencing cavity, r is the radius of the fundamental frequency filter hole, t is the thickness of the lower volute, and pi is pi.

[0041] Specifically, the fundamental frequency of the fan can be calculated using the formula, where n is the fan speed and z is the number of blades (110). This fundamental frequency can be accurately calculated through measurement and calculation. Similarly, the fundamental frequency filter formula shows that c is the sound velocity of the airflow, V is the volume of the silencing cavity (which can be calculated and measured), r is the radius of the 320mm fundamental frequency filter hole (which can be calculated and measured using instruments), and t is the thickness of the 300mm lower volute (which can be calculated and measured using instruments). When designing the silencing cavity, the fundamental frequency of the fan can be determined, and the volume of the silencing cavity, the thickness of the 300mm lower volute, and the radius of the 320mm fundamental frequency filter hole can be adjusted to ensure that the fundamental frequency filter frequency matches the fundamental frequency of the fan. This results in a more reasonable and suitable design, making the sweeper design more flexible and achieving the most significant reduction in fundamental frequency filtering noise, thus minimizing the impact of the fan's noise on the user.

[0042] In this solution, preferably, the first sidewall 410 and / or the second sidewall 420 are displaceably connected to the silencing cover 400 and / or the lower volute 300. When the first sidewall 410 and / or the second sidewall 420 move, their positions are fixed by a retaining structure. Thus, the volume V of the silencing cavity can be adjusted by changing the distance between the first sidewall 410 and the second sidewall 420, further matching f0 with f1 (for example, the frequency may change after machine aging, or other adjustment requirements may be met). There are many types of retaining structures, such as those using clips or screws, which will not be elaborated or limited here.

[0043] In some embodiments of the present invention, a wideband filter hole 330 is further included, and the lower volute 300 is provided with the wideband filter hole 330; a second noise-absorbing cavity corresponding to the wideband filter hole 330 is provided on the outer side of the lower volute 300.

[0044] Reference Figure 1 Specifically, a wideband filter hole 330 is also provided on the lower volute 300, penetrating the lower volute 300. In other embodiments of the present invention, the wideband filter hole 330 can be set to four, five, seven, eight, etc. When the sweeper's fan is running, the fan blade 110 rotates at high speed, and the fan blade 110 simultaneously rotates the surrounding medium, causing the wideband filter to generate noise. The airflow flows through the channel in the volute, and as the airflow passes through the multiple wideband filter holes 330 in the channel, the noise generated by the wideband filter gradually decreases when the sweeper is cleaning, reducing the noise impact of the wideband filter on the user. The evenly spaced wideband filter holes 330 allow the noise generated by the wideband filter to be absorbed evenly, ensuring the normal pressurization of the fan when the sweeper is cleaning. A second silencing chamber can be provided in the space between the lower volute 300 and the silencing cover plate 400, below the wideband filter hole 330. The silencing cover 400 has two vertically arranged sidewalls facing upwards. These two sidewalls are spaced apart and parallel to each other, with their upper surfaces abutting against the inner and outer sidewalls to form a hollow second silencing cavity. When the sweeper is working, the fan rotates at high speed, and the fan blades 110 simultaneously rotate, generating airflow from the surrounding medium. This airflow enters through the volute tongue 310 and flows into the interior of the volute. Upon entering the wideband filter hole 330, which connects to the silencing cavity, the airflow enters the silencing cavity and is filtered by the resonant silencing structure of the cavity, thus reducing the noise generated by the wideband filter. The connection between the silencing cavity and the wideband filter hole 330 reduces the noise generated by the wideband filter during cleaning, minimizing the noise impact on the user.

[0045] In some embodiments of the present invention, a plurality of the broadband filter holes 330 are uniformly arranged in the lower volute 300.

[0046] Reference Figure 1Specifically, a wideband filter hole 330 is provided on the lower volute 300, and the wideband filter holes 330 are evenly distributed on the lower volute 300, with equal distances between each wideband filter hole 330. When the sweeper's fan is running, the fan blade 110 rotates at high speed, and the fan blade 110 simultaneously rotates the surrounding medium, causing noise generated by the wideband filter. The evenly spaced wideband filter holes 330 allow the noise generated by the wideband filter to be absorbed evenly, ensuring normal pressurization of the fan during sweeper cleaning operations.

[0047] In some embodiments of the present invention, a first sound-absorbing cotton is further included, wherein the first sound-absorbing cotton is disposed below the broadband filter hole 330 and fills the second sound-absorbing cavity.

[0048] Specifically, a sound-absorbing cotton is provided in the space between the lower volute 300 and the sound-absorbing cover plate 400. However, this space is outside the first sound-absorbing cavity 600 and does not include the internal space of the first sound-absorbing cavity 600. A first sound-absorbing cotton 500 is provided in the space between the lower volute 300 and the sound-absorbing cover plate 400, and this space is completely covered by the sound-absorbing cotton. The space is only connected to the volute through the broadband filter hole 330. The sound-absorbing cotton is located below the broadband filter hole 330. When the blower of the sweeper is running, the airflow flows in the volute. After the airflow passes through multiple broadband filter holes 330 and enters the space between the lower volute 300 and the sound-absorbing cover plate 400, the overall airflow velocity in the volute is reduced, the pressure fluctuation is reduced, and the overall noise level is reduced. At the same time, the sound-absorbing cotton located below the multiple broadband filter holes 330 in the airflow passage comes into contact with the airflow. The sound-absorbing cotton can also absorb the noise generated by the broadband filter, thus achieving the effect of sound insulation for the blower. The completely sealed sound-absorbing cotton can greatly reduce the overall airflow speed inside the volute and the noise generated by wideband filtering.

[0049] In some embodiments of the present invention, a second sound-absorbing cotton is provided in the first sound-absorbing cavity 600, and the second sound-absorbing cotton is provided at the opening of the fundamental frequency filter hole 320; a certain space is left between the second sound-absorbing cotton and the sound-absorbing cover plate 400 in the first sound-absorbing cavity 600, and the volume of the space is the volume of the first sound-absorbing cavity 600.

[0050] A second layer of sound-absorbing cotton can also be installed in the first sound-absorbing cavity 600. The second layer of sound-absorbing cotton is located at the opening of the fundamental frequency filter hole 320. The second layer of sound-absorbing cotton covers the fundamental frequency filter but does not completely seal the first sound-absorbing cavity 600. There is a certain gap between the sound-absorbing cotton and the sound-absorbing cover plate 400. The volume of the gap is the volume V of the first sound-absorbing cavity 600 (calculated by substituting into relevant formulas, such as the formula mentioned above). The sound-absorbing cotton can absorb the sound energy of the airflow, reducing the noise generated by the sweeper. The first sound-absorbing cavity 600 can reduce the noise of the fundamental frequency filter, thus reducing the noise impact on the user.

[0051] In some embodiments of the present invention, the upper volute 200 and the lower volute 300 are snap-fit ​​connected.

[0052] Reference Figure 3 Specifically, two downward-protruding annular grooves are provided on the outer wall of the upper volute 200, and two connecting parts protruding away from the outer wall are also provided on the outer wall of the lower volute 300. The annular grooves of the upper volute 200 and the connecting parts on the outer wall of the lower volute 300 are matched in position and shape, which can connect the upper volute 200 and the lower volute 300. Since the annular grooves of the upper volute 200 and the connecting parts on the outer wall of the lower volute 300 are detachable, it is very convenient to disassemble the upper volute 200 and the lower volute 300, which improves the efficiency of maintenance and repair of the fan noise reduction device.

[0053] A sweeper according to a second aspect of the present invention includes a fan noise reduction device according to the first aspect of the present invention described above.

[0054] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A fan noise reduction device, characterized in that, include: The fan includes fan blades and a motor; Upper volute, wherein the upper volute is disposed at the top of the fan blade; The lower volute is connected to the upper volute and encloses the fan. The lower volute is provided with a base frequency filter hole that penetrates through the lower volute. The motor is located at the bottom of the lower volute and is connected to the fan blade via a rotating shaft; The lower volute is provided with a first noise-absorbing cavity corresponding to the fundamental frequency filter hole on the side away from the fan blade; It also includes: a sound-absorbing cover plate, on which a first side wall and a second side wall are vertically arranged, the first side wall and the second side wall are spaced apart, and a sound-absorbing channel is also formed on the side of the lower volute away from the fan blade; The silencing cover is disposed at the bottom of the lower volute. The ends of the first sidewall and the second sidewall away from the silencing cover contact the bottom of the lower volute and are engaged in the silencing channel. The silencing cover, the first sidewall, the second sidewall, and the sidewall of the silencing channel together form a first silencing cavity.

2. The fan noise reduction device according to claim 1, characterized in that, Also includes: The volute tongue is located at the air outlet of the lower volute, and the base frequency filter hole is located in the area near the air outlet.

3. The fan noise reduction device according to claim 1, characterized in that, The fundamental frequency filter frequency is set to be equal to the fundamental frequency of the wind turbine, and the fundamental frequency filter frequency satisfies the formula: f0=c / 2*pi*((pi*r) 2 ) / V / (t+1.6r)) 0.5 The fundamental frequency of the fan is: f1 = n * z / 60; Where c is the sound speed of the airflow, n is the fan speed, z is the number of fan blades, V is the volume of the first silencing cavity, r is the radius of the fundamental frequency filter hole, t is the thickness of the lower volute, and pi is pi.

4. The fan noise reduction device according to claim 1, characterized in that, Also includes: A wideband filter hole is provided on the lower volute; a second noise-absorbing cavity corresponding to the wideband filter hole is provided on the outer side of the lower volute.

5. The fan noise reduction device according to claim 4, characterized in that, Several of the aforementioned wideband filter holes are evenly distributed on the lower volute.

6. The fan noise reduction device according to claim 4, characterized in that, Also includes: The first sound-absorbing cotton is disposed below the broadband filter hole and filled in the second sound-absorbing cavity.

7. The fan noise reduction device according to claim 1, characterized in that, A second sound-absorbing cotton is provided in the first sound-absorbing cavity, and the second sound-absorbing cotton is located at the opening of the fundamental frequency filter hole; a certain space is left between the second sound-absorbing cotton and the sound-absorbing cover plate in the first sound-absorbing cavity, and the volume of the space is the volume of the first sound-absorbing cavity.

8. The fan noise reduction device according to claim 1, characterized in that, The upper volute and the lower volute are snap-fitted together.

9. A sweeping machine, comprising a fan noise reduction device as described in any one of claims 1 to 8.

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