Fan noise reduction structure for surface cleaning device

Abstract

The invention discloses a fan noise reduction structure for a surface cleaning device, which comprises a wind scooper covering the outer side of a fan, the wind scooper is internally provided with an exhaust channel for communicating an air outlet of the fan with the outside, and the fan noise reduction structure is characterized in that the exhaust channel comprises a first air channel and a second air channel which are sequentially arranged along the airflow flowing direction; the first air channel is configured to guide airflow to flow in the first direction, the second air channel is configured to guide airflow to flow in the second direction opposite to the first direction, multiple stages of flow slowing plates are arranged in the exhaust channel, and the stage number of the flow slowing plates in the first air channel is larger than that of the flow slowing plates in the second air channel. According to the surface cleaning device, speed reduction and noise reduction can be achieved by prolonging the flowing path and increasing the on-way resistance loss of gas in the limited noise reduction structure space, and therefore the good compatible effect is achieved on the aspects of the size and the noise reduction effect of the surface cleaning device.

Description

Technical Field

[0001] This application belongs to the field of cleaning device technology, specifically relating to a fan noise reduction structure for a surface cleaning device. Background Technology

[0002] Current surface cleaning devices, such as vacuum cleaners and floor scrubbers, all rely on fans to generate negative pressure to suck up dirt during the cleaning process. These fans are generally quite powerful, resulting in significant noise during operation. Furthermore, the fans are often located in the handheld unit for easy gripping. Generally, the handheld unit cannot be designed to be too large, otherwise it will affect the user's grip experience and also the cleaning experience of floor scrubbers and vacuum cleaners in low-lying areas. A larger handheld unit restricts the angle of cleaning in low-lying areas. Therefore, designing a low-cost noise-reducing structure within the limited diameter and height of the handheld unit is crucial. Currently, surface cleaning devices on the market achieve noise reduction while maintaining miniaturization by adding multiple sound-absorbing cotton pieces, but this method has minimal noise reduction effect.

[0003] Patent document CN220293561U discloses a power assembly with a noise reduction structure for use in cleaning equipment. The assembly includes a main body containing an airflow chamber. An airflow generator for generating airflow is installed within the airflow chamber. The main body also has an air inlet communicating with the airflow chamber. The airflow chamber is located on the inner ring of the main body. A drainage chamber is located on the outer ring of the main body and is at least partially annularly distributed. The drainage chamber includes a first drainage area and a second drainage area spaced apart in the annular direction. A drainage assembly is installed within the drainage chamber. The component is provided with multiple drainage holes in a vertically penetrating structure. The drainage holes are arranged in a spaced-out structure in the annular and radial directions of the drainage cavity. The lower region of the first drainage zone is connected to the airflow cavity, and the upper region of the first drainage zone is connected to the upper region of the second drainage zone. This allows the airflow in the airflow cavity to be turned and enter the first drainage zone to flow upward, and the airflow to be turned and enter the second drainage zone. The lower part of the component body is provided with an air outlet that is connected to the lower region of the second drainage zone. The airflow flows downward in the second drainage zone and is discharged outward through the air outlet. In this technical solution, the arrangement of the first and second drainage areas and the drainage holes results in the airflow exiting the airflow cavity and forming a U-shape along the flow path of the first and second drainage areas. The short airflow path prevents the airflow velocity from being effectively reduced, leading to poor noise reduction. To achieve the desired noise reduction effect, it is necessary to increase the overall volume of the power component in this technical solution to a certain extent, in order to extend the airflow path. However, this increase in volume will enlarge the handheld part of the cleaning equipment, affecting the usage scenarios of the cleaning equipment and reducing the user experience. Summary of the Invention

[0004] This application provides a fan noise reduction structure for a surface cleaning device to solve the technical problems of large size and poor noise reduction effect of existing fan noise reduction structures for surface cleaning devices.

[0005] The technical solution adopted in this application is as follows:

[0006] A noise reduction structure for a fan in a surface cleaning device includes an air guide shroud covering the outside of the fan. The air guide shroud contains an exhaust channel connecting the fan outlet to the outside. The exhaust channel includes a first air duct and a second air duct arranged sequentially along the airflow direction. The first air duct is configured to guide the airflow in a first direction, and the second air duct is configured to guide the airflow in a second direction opposite to the first direction. The exhaust channel contains multiple levels of flow dampers, with the number of flow damper levels in the first air duct being greater than the number of flow damper levels in the second air duct.

[0007] The fan noise reduction structure described in this application further includes the following additional technical features:

[0008] The slow flow plate is provided with a slow flow channel. At least two levels of the slow flow plates extend radially outward along the fan. The slow flow channels on adjacent two levels of the slow flow plates are at least partially staggered in the circumferential direction around the axis of the fan.

[0009] The slow flow plate is provided with a slow flow channel. The slow flow plate includes a primary plate extending along the axial direction of the fan. The primary plate is arranged at the air inlet of the exhaust passage. The air flow enters the first air duct from the slow flow channel of the primary plate.

[0010] It further includes a diversion baffle connected to the slow flow plate. The diversion baffle jointly forms the side walls of the first air duct and the second air duct. At least part of the slow flow plates arranged at intervals along the axial direction of the fan overlap with the projection of the diversion baffle.

[0011] A slow flow cavity is formed between adjacent two levels of the slow flow plates. The number of levels of the slow flow cavity is K, and K is an integer greater than or equal to 3. Among them, a partition plate is provided in the M - th level slow flow cavity to divide it into multiple diversion cavities. The air flow is diverted from the (M - 1)-th level slow flow cavity into the diversion cavities and then converges in the (M + 1)-th level slow flow cavity, where 1 < M < K and M is an integer.

[0012] [[ID=??]]

[0013] There is an exhaust cavity in the second air duct, which is located on the downstream side of the K - th level slow flow cavity and communicates with the outside. The noise reduction structure further includes a diversion baffle for separating the exhaust cavity and the (K - 1)-th level slow flow cavity. The height of the diversion baffle extending along the axial direction of the fan is greater than the height of the (K - 1)-th level slow flow cavity, so that the projection of the exhaust cavity along the axial direction of the fan at least partially overlaps with the projection of the (K - 2)-th level slow flow cavity along the axial direction of the fan.

[0014] The air guide cover is provided with a ventilation area connecting the air outlet and the exhaust passage, and an exhaust cavity connecting the exhaust passage and the outside. The ventilation area and the exhaust cavity at least partially overlap in the projection along the axial direction of the fan 。

[0015] It should be noted that there seems to be an error in the original text where the line tag is followed by an incorrect which might be a misnumbering. I've translated it as best as possible based on the provided content.The air guide hood is provided with an exhaust chamber that communicates with the outside. An air guide plate is provided inside the exhaust chamber. The air guide plate is configured to guide the airflow to flow in a third direction. The third direction is arranged at an angle to the second direction.

[0016] The noise reduction structure also includes a sealing cover covering the air guide shroud. The sealing cover and the air guide shroud cooperate to form a sealing cavity. The sealing cavity is connected to the first-stage slow-flow cavity of the first air duct through a sound-absorbing hole.

[0017] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows:

[0018] 1. The design of the first and second air ducts in this application guides airflow in a preset direction, avoiding disordered flow, improving exhaust efficiency, and thus ensuring the suction power of the surface cleaning device and enhancing cleaning effect. Furthermore, the first and second air ducts guide airflow in opposite directions, effectively dispersing and reducing the direct impact of airflow, thereby reducing noise generation. The first and second air ducts are arranged sequentially along the airflow direction, with the number of deflector plates in the first duct being greater than that in the second duct. This allows the airflow to decelerate rapidly upon entering the first duct, reducing vibration and noise caused by high-speed airflow. Moreover, the variation in the number of deflector plates in the first and second ducts helps to achieve multi-stage airflow diversion throughout the exhaust channel, further refining airflow control and gradually reducing wind speed, thereby helping to reduce noise caused by sudden changes in wind speed and resulting airflow disturbance.

[0019] Furthermore, by setting up a first air duct, a second air duct, and multiple flow dampers, not only can the wind speed be varied, but the flow path of the gas can also be effectively extended. Within the limited space of the noise reduction structure, the gas resistance loss along the flow path is increased by extending the flow path, thereby achieving deceleration and noise reduction. This results in a good balance between the size of the surface cleaning device and the noise reduction effect.

[0020] 2. In a preferred embodiment of this application, at least two stages of flow deflectors extend radially outward from the fan. The flow deflector channels on adjacent stages are at least partially staggered circumferentially around the fan axis. This allows airflow to flow circumferentially through the flow deflector channels to the next stage, thereby extending the airflow path and enabling multiple changes in airflow direction during circumferential flow. This increases friction loss and reduces noise. This embodiment helps to fully utilize the circumferential space of the air guide shroud to extend the airflow path, achieving high utilization of the circumferential space of the air guide shroud. It also helps to reduce the axial dimension of the entire noise reduction structure, thus contributing to the miniaturization of the noise reduction structure.

[0021] 3. As a preferred embodiment of the present application, the flow retarder plate includes a primary plate extending along the axial direction of the fan. The primary plate is provided at the air inlet of the exhaust passage. The air flow enters the first air duct through the flow retarder passage of the primary plate. The primary plate extends along the axial direction of the fan, which enables the air flow flowing out from the fan outlet to move along the axial direction of the fan and enter the first air duct through the flow retarder passage on the primary plate, thereby extending the moving path of the air flow along the axial direction of the fan, making full use of the axial dimension of the air guide cover, and thus contributing to the miniaturization of the noise reduction structure. Moreover, when the air flow flows from the fan outlet to the primary plate and passes through the primary plate, it undergoes multiple turns, thereby achieving the deceleration of the air flow and enhancing the noise reduction effect.

[0022] 4. As a preferred embodiment of the present application, the noise reduction structure further includes a flow guiding baffle. The flow guiding baffle jointly forms the side walls of the first air duct and the second air duct. At least part of the flow retarder plates arranged at intervals along the axial direction of the fan overlap with the projection of the flow guiding baffle. In this embodiment, by making full use of the axial space and radial space of the air guide cover, the flowing path of the air flow is effectively extended, so that the air flow undergoes multi-directional turns, divergences, convergences, etc. during the whole flowing process, increasing its frictional resistance loss along the way, reducing the air flow velocity, and thus enhancing the noise reduction effect.

[0023] 5. As a preferred embodiment of the present application, a flow retarder cavity is formed between adjacent two-stage flow retarder plates. The number of stages of the flow retarder cavity is K, and K is an integer greater than or equal to 3. Among them, a partition is provided in the Mth-stage flow retarder cavity to divide it into multiple diversion cavities. The air flow is diverted from the (M - 1)th-stage flow retarder cavity into the partition cavity and then converges in the (M + 1)th-stage flow retarder cavity, where 1 < M < K and M is an integer. With such a setting, when the air enters the Mth-stage flow retarder cavity from the (M - 1)th-stage flow retarder cavity, the air flow can be dispersed, and then converges and is discharged after entering the (M + 1)th-stage flow retarder cavity. By optimizing the flowing path of the air flow, the exhaust passage is further extended and the noise is further degraded.

[0024] 6. As a preferred embodiment of the present application, a sealing cover is provided above the air guide cover. The sealing cover and the air guide cover cooperate to enclose a sealing cavity. The air guide cover is provided with a sound absorption hole connecting the sealing cavity and the first air duct. The setting of the sealing cover and the sealing cavity can, on the one hand, reduce the transmission of the noise during the operation of the fan to the outside, and on the other hand, by providing a sound absorption hole connecting the sealing cavity and the first air duct, a low-frequency muffler can be formed through their cooperation, enabling the noise and vibration of the air flow flowing in the first air duct to enter the sealing cavity through reflection and refraction through the sound absorption hole, enhancing the noise reduction effect.

[0025] 7. As a preferred embodiment of this application, the air guide hood is provided with a ventilation area connecting the air outlet and the exhaust channel, and an exhaust cavity connecting the exhaust channel and the outside. The vertical projection of the ventilation area and the vertical projection of the exhaust cavity at least partially overlap, thereby further reducing the axial dimension of the noise reduction structure on the basis of extending the airflow path, realizing the miniaturization of the noise reduction structure, and thus contributing to the miniaturization of the surface cleaning device. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0027] Figure 1 This is a front view of a noise reduction structure according to one embodiment of this application;

[0028] Figure 2 This is an exploded view of a noise reduction structure along with a fan according to one embodiment of this application;

[0029] Figure 3 for Figure 1 Sectional view along axis AA;

[0030] Figure 4 This application describes a three-dimensional structure of a noise reduction structure in one embodiment of the noise reduction structure, along with the fan. Figure 1 The arrows indicate the direction of the airflow.

[0031] Figure 5 This application discloses an embodiment of a noise reduction structure, including a three-dimensional fan. Figure 2 The arrows indicate the direction of the airflow.

[0032] Figure 6 This application describes a three-dimensional structure of a noise reduction structure in one embodiment of the noise reduction structure, along with the fan. Figure 3 To avoid confusion between the markings of each level of flow buffer and the markings of each level of flow buffer cavity, arrow indicators have been added to the lead lines representing each level of flow buffer cavity in this figure.

[0033] Figure 7 This is a top view of a noise reduction structure when the sealing cap is removed according to one embodiment of this application;

[0034] Figure 8 This is a bottom view of the air guide cover according to one embodiment of this application;

[0035] Figure 9 This is a side view of a noise reduction structure according to one embodiment of this application;

[0036] Figure 10 for Figure 9BB-direction sectional view.

[0037] in,

[0038] 1. Fan;

[0039] 2. Air guide hood; 21. Second-stage flow deflector; 22. Third-stage flow deflector; 23. Fourth-stage flow deflector; 24. Flow deflector channel; 25. Flow deflector hole; 26. Primary plate; 27. Ventilation zone; 28. First-stage flow deflector cavity; 29. ​​Second-stage flow deflector cavity; 210. Third-stage flow deflector cavity; 211. Partition; 212. Flow deflector baffle; 213. Exhaust cavity; 214. First-stage cover; 215. Second-stage cover; 216. Outer cover; 217. Air guide plate; 218. Silencing hole;

[0040] 3. Vibration damping components; 31. Vibration damping structure;

[0041] 4. Sealing cap;

[0042] 5. Sealed cavity. Detailed Implementation

[0043] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0044] Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below. It should be noted that, unless otherwise specified, the embodiments of this application and the features thereof can be combined with each other.

[0045] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 this application.

[0046] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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 communication connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0047] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "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 this application. 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 can be combined in any suitable manner in one or more embodiments or examples.

[0048] like Figure 1 , Figure 4 and Figure 5 As shown, a noise reduction structure for a fan 1 in a surface cleaning device includes an air guide shroud 2 covering the outside of the fan 1. The air guide shroud 2 has an exhaust channel connecting the air outlet of the fan 1 to the outside. The exhaust channel includes a first air duct and a second air duct arranged sequentially along the airflow direction. The first air duct is configured to guide the airflow to flow in a first direction, and the second air duct is configured to guide the airflow to flow in a second direction opposite to the first direction. The exhaust channel has multiple levels of flow damping plates, and the number of flow damping plates in the first air duct is greater than the number of flow damping plates in the second air duct.

[0049] The design of the first and second air ducts in this application guides airflow in a preset direction, avoiding disordered flow, improving exhaust efficiency, and thus ensuring the suction power of the surface cleaning device and enhancing cleaning effectiveness. Furthermore, the first and second air ducts guide airflow in opposite directions, effectively dispersing and reducing direct airflow impact, thereby reducing noise generation. The first and second air ducts are arranged sequentially along the airflow direction, with the number of deflector stages in the first duct being greater than that in the second duct. This allows the airflow to decelerate rapidly upon entering the first duct, reducing vibration and noise caused by high-speed airflow. Moreover, the variation in the number of deflector stages in the first and second air ducts helps to achieve multi-stage airflow diversion throughout the exhaust channel, further refining airflow control and gradually reducing wind speed, thereby helping to reduce noise caused by sudden changes in wind speed and resulting airflow disturbance.

[0050] Furthermore, by setting up a first air duct, a second air duct, and multiple flow dampers, not only can the wind speed be varied, but the flow path of the gas can also be effectively extended. Within the limited space of the noise reduction structure, the gas resistance loss along the flow path is increased by extending the flow path, thereby achieving deceleration and noise reduction. This results in a good balance between the size of the surface cleaning device and the noise reduction effect.

[0051] To further improve the noise reduction effect, in this application, the first direction and the second direction are opposite. Figure 4 and Figure 5 Taking the directions shown as an example, the first direction is downward flow, and the second direction is upward flow. Due to gaps, friction, collisions, and other factors, the flow of air in the exhaust duct is very complex. Flowing in the first direction means that the overall airflow trend is generally downward; it is not absolutely downward, but rather exhibits a generally downward trend. Flowing in the second direction means that the overall airflow trend is generally upward; it is not absolutely upward, but rather exhibits a generally upward trend. As a possible method for determining the gas flow direction, the flow direction formed by connecting the inlet and outlet of the first duct can be taken as the first direction, and the airflow direction of the second duct can be determined similarly. When the surface cleaning device is cleaning a floor with liquid, the liquid collides with the pipes and other components during the suction process, producing small droplets. These droplets are also drawn into the fan along with the air and then discharged together. Because this air contains water vapor, its density is reduced. Theoretically, this mixed gas, after being discharged, will have a tendency to rise relative to dry air. In this solution, the airflow discharged by the fan is forced to flow downward under the action of the first air duct, driving the airflow in the opposite direction to its own upward trend, thereby using the forced downward flow of the airflow to better and faster reduce the airflow speed.

[0052] In this application, the number of stages of the flow deflector refers to the number of a series of flow deflectors installed in the exhaust duct to change the direction and speed of airflow.

[0053] The flow-regulating plate of this application is provided with a flow-regulating channel, and this application does not limit the specific structural form of the flow-regulating channel. In one embodiment, the flow-regulating channel is a flow-regulating hole provided on the flow-regulating plate. In another embodiment, the flow-regulating channel is a flow-regulating gap existing on the air guide shroud for airflow.

[0054] As a preferred embodiment of this application, such as Figure 4 , Figure 5 and Figure 6As shown, at least two stages of flow deflectors extend radially outward along the fan 1, and the flow deflector channels 24 on adjacent stages are at least partially offset circumferentially around the axis of the fan 1. This arrangement allows airflow to flow circumferentially along the fan 1 and through each flow deflector channel 24 to the next stage, thereby extending the airflow path and enabling multiple changes in airflow direction during circumferential flow, increasing friction loss and achieving noise reduction. This embodiment helps to fully utilize the circumferential space of the air guide shroud 2 to extend the airflow path, achieving high utilization of the circumferential space of the air guide shroud 2, and helping to reduce the axial dimension of the entire noise reduction structure, thus contributing to the miniaturization of the noise reduction structure.

[0055] As a preferred embodiment of this application, such as Figure 4 and Figure 6 As shown, the flow-damping plate includes a primary plate 26 extending along the axial direction of the fan 1. The primary plate 26 is located at the air inlet of the exhaust duct, and the airflow enters the first air duct through the flow-damping channel 24 on the primary plate 26. The primary plate 26 extends along the axial direction of the fan 1, allowing the airflow to move along the axial direction of the fan 1 after exiting the fan outlet and pass through the flow-damping channel 24 on the primary plate 26 to enter the first air duct. This extends the airflow path along the axial direction of the fan 1, fully utilizing the axial dimensions of the air guide shroud 2, thus contributing to the miniaturization of the noise reduction structure. Furthermore, the airflow undergoes multiple turns as it flows from the fan outlet to and passes through the primary plate 26, thereby reducing the airflow speed and improving the noise reduction effect.

[0056] As a preferred embodiment of this application, such as Figure 5 As shown, the noise reduction structure also includes a flow guide baffle 212 connected to the flow damper. The flow guide baffle 212 together form the sidewalls of the first and second air ducts. At least a portion of the flow dampers, arranged at intervals along the axial direction of the fan 1, overlap with the projection of the flow guide baffle 212. This embodiment effectively extends the airflow path by fully utilizing the axial and radial spaces of the air guide shroud 2. This allows the airflow to undergo multi-directional turning, splitting, and converging during the entire flow process, increasing its friction loss and reducing the airflow velocity, thereby improving the noise reduction effect.

[0057] As a preferred embodiment of this application, such as Figure 4 , Figure 5 and Figure 6As shown, a flow buffering cavity is formed between two adjacent flow buffering plates. The number of levels of the flow buffering cavity is K, where K is an integer greater than or equal to 3. Among them, a partition 211 is provided in the Mth-level flow buffering cavity to divide it into multiple flow splitting cavities. After the air flow splits from the (M - 1)th-level flow buffering cavity and enters the flow splitting cavities, it converges in the (M + 1)th-level flow buffering cavity, where 1 < M < K and M is an integer. The flow buffering cavity is a spatial structure with a cross-sectional area in the air flow direction larger than that of the flow buffering channel 24. With such a setting, when the wind enters the Mth-level flow buffering cavity from the (M - 1)th-level flow buffering cavity, the air flow can be dispersed, and then converges and is discharged after entering the (M + 1)th-level flow buffering cavity. By optimizing the air flow path, the exhaust air channel can be further extended and the noise can be further reduced.

[0058] As a preferred embodiment of this embodiment, as Figure 4 , Figure 5 and Figure 6 shown, the number of levels of the flow buffering plates in the first air duct is three, and the number of levels of the flow buffering plates in the second air duct is one. For the convenience of description, the flow buffering plates provided in the first air duct are defined as the primary plate 26, the second-level flow buffering plate 21, and the third-level flow buffering plate 22, and the flow buffering plate provided in the second air duct is defined as the fourth flow buffering plate 23. The second-level flow buffering plate 21 and the third-level flow buffering plate 22 are arranged in sequence along the axis direction of the air guide cover 2 to divide the space inside the air guide cover 2 into the first-level flow buffering cavity 28, the second-level flow buffering cavity 29, and the third-level flow buffering cavity 210. The third-level flow buffering plate 22 located in the first air duct and the fourth-level flow buffering plate 23 located in the second air duct are separated on opposite sides of the air guide cover 2, and the third-level flow buffering cavity 210 connects the first air duct and the second air duct.

[0059] By providing multiple levels of flow buffering plates to divide the space inside the air guide cover 2 into multiple levels of flow buffering cavities along the axis direction of the air guide cover 2, the wind flows step by step along each level of flow buffering cavity. And in the same flow buffering cavity, the air flow will flow in this space layer along a preset flow path, so that the guidance of the gas flow can be realized circumferentially and axially along the air guide cover 2 within a limited space, greatly extending the gas flow path. On the one hand, it can increase the frictional resistance loss during the flow process to achieve speed reduction and noise reduction. On the other hand, it can avoid the increase in vortex phenomena caused by disordered flow to achieve noise reduction.

[0060] Furthermore, both the second-stage flow-delay plate 21 and the third-stage flow-delay plate 22 are provided with multiple flow-delay channels 24 spaced apart along their respective circumferences, and each flow-delay channel 24 is provided with flow-delay holes 25. The arrangement of multiple flow-delay channels 24 allows the airflow to flow circumferentially within the same level of flow-delay chamber, passing through the flow-delay holes 25 of each flow-delay channel 24 to reach the next level of flow-delay chamber. This extends the flow path of the airflow within the same flow-delay chamber and enables multiple changes in airflow direction during circumferential flow, increasing the friction loss of the airflow and achieving noise reduction. The arrangement of the flow-delay holes 25 within the flow-delay channels 24 allows the airflow to be more evenly dispersed when passing through the flow-delay plates, reducing concentrated airflow impact and thus reducing noise. Moreover, the design of the flow-delay holes 25 helps to reduce the resistance of the airflow when passing through the flow-delay channels 24, improving the operating efficiency of the fan 1.

[0061] In this embodiment, the number and shape of the flow-slowing holes 25 in each flow-slowing channel 24 are not limited. The number of flow-slowing holes 25 in each flow-slowing channel 24 can be the same or different, and the shape and size of the flow-slowing holes 25 in each flow-slowing channel 24 can be the same or different.

[0062] Furthermore, to prevent adjacent airflows from colliding and generating vortices when entering each slow-flow channel 24 within the same slow-flow cavity, thus avoiding noise escalation, each slow-flow cavity is equipped with a baffle 211 to separate adjacent slow-flow channels 24. Figures 4 to 6 For example, in a specific example, the second-stage flow-retarding plate 21 is provided with two spaced-apart flow-retarding channels 24, and the third-stage flow-retarding plate 22 is provided with two spaced-apart flow-retarding channels 24. Each flow-retarding channel 24 is provided with several flow-retarding holes 25. The first-stage flow-retarding cavity 28 is provided with a partition 211 between two adjacent flow-retarding channels 24 to prevent the two streams flowing towards the two flow-retarding channels 24 from colliding. Similarly, the second-stage flow-retarding cavity 29 is also provided with partitions 211.

[0063] In a preferred embodiment of this invention, both the second-stage flow-delay plate 21 and the third-stage flow-delay plate 22 are provided with flow-delay channels 24. The horizontal projections of the flow-delay channels 24 of the second-stage flow-delay plate and the third-stage flow-delay plate do not overlap at least partially. The primary plate 26 is provided with a ventilation area 27 connecting the air outlet and the exhaust duct. The ventilation area 27 and the flow-delay channels 24 of the third-stage flow-delay plate 22 are located on the same side of the axis of the air guide hood 2. The horizontal projections of the flow-delay channels 24 of the second-stage flow-delay plate 21 and the third-stage flow-delay plate 22 do not overlap at least partially, which allows the airflow to form a meandering flow when flowing from the first-stage flow-delay cavity 28 to the second-stage flow-delay cavity 29. This further extends the flow path of the airflow in the first air duct within a limited space, not only achieving noise reduction but also contributing to the miniaturization of the noise reduction structure. The primary plate 26 is provided with a ventilation zone 27 connecting the air outlet of the ventilator 1 and the exhaust duct. The ventilation zone 27 and the flow channel 24 of the third-stage flow buffer plate 22 are located on the same side of the axis of the air guide hood 2. This arrangement allows the airflow to be introduced into the first air duct from the ventilation zone 27 and then dispersed circumferentially along the first-stage flow buffer cavity 28 to reach the flow channel 24 of the second-stage flow buffer plate 21. The airflow then flows through the flow holes 25 of the flow channel 24 of the second-stage flow buffer plate 21 to the second-stage flow buffer cavity 29. Since the horizontal projection of the flow channel 24 of the third-stage flow buffer plate 22 is at least partially the same as that of the second-stage flow buffer plate 21, the airflow is also affected by the flow of the third-stage flow buffer plate 22. The projections of the slow-flow channel 24 in the horizontal direction do not overlap, so that after the airflow enters the second-stage slow-flow cavity 29, it will flow along the circumference of the second-stage slow-flow cavity 29 until it flows to the slow-flow channel 24 of the third-stage slow-flow plate 22. Therefore, in the entire flow path from the ventilation zone 27 to the slow-flow channel 24 of the third-stage slow-flow plate 22, from the axial direction of the air guide hood 2, the airflow in the first air duct has experienced a meandering flow pattern of first dispersing and then converging. Within a limited space, the flow path of the gas is greatly extended, thereby effectively reducing the noise in the gas flow process.

[0064] like Figures 4 to 6 As shown, in a specific example, the second-stage flow deflector 21 is provided with two spaced-apart flow deflector channels 24. The two flow deflector channels 24 are located on two opposite sides of the second-stage flow deflector 21 in the radial direction, so that the airflow can be dispersed to both sides after entering the first air duct and flow into the second-stage flow deflector cavity 29 through the flow deflector channels 24 of the second-stage flow deflector 21 respectively. The flow deflector channels 24 on the third-stage flow deflector 22 are also spaced-apart. Preferably, the flow deflector channels 24 on the third-stage flow deflector 22 are substantially perpendicular to the radial direction of the flow deflector channels 24 on the second-stage flow deflector 21 in the radial direction of the third-stage flow deflector 22, so as to further extend the flow path of the wind into the second-stage flow deflector cavity 29 and achieve noise reduction.

[0065] Furthermore, such as Figure 6As shown, the radial direction of the air guide hood 2 where the ventilation zone 27 and the slow flow channel 24 on the third-stage slow flow plate 22 are located is Da, and the radial direction of the air guide hood 2 where the slow flow channel 24 on the second-stage slow flow plate 21 is located is Db. Da and Db are perpendicular to each other, so that the airflow flows from the ventilation zone 27 into the first air duct and then disperses to both sides to enter the second-stage slow flow cavity 29 through the two slow flow channels 24 on the second-stage slow flow plate 21. The airflow entering the second-stage slow flow cavity 29 continues to move along the circumference of the second-stage slow flow cavity 29 to enter the slow flow channel 24 of the second-stage slow flow cavity 29. Through this meandering flow mode, the flow path of the gas is extended, thereby achieving noise reduction.

[0066] In a specific example, such as Figure 4 and Figure 6 As shown, the second-stage slow-flow chamber 29 is equipped with a baffle 211, which divides the second-stage slow-flow chamber 29 into at least two diversion chambers. After the airflow is diverted from the first-stage slow-flow chamber 28 into the diversion chambers, it converges in the third-stage slow-flow chamber 210. This arrangement allows the airflow to be dispersed when it enters the second-stage slow-flow chamber 29 from the first-stage slow-flow chamber 28, and then converges in the third-stage slow-flow chamber 210 before being discharged. This further extends the exhaust channel and reduces noise levels.

[0067] In a specific example, such as Figure 4 and Figure 6 As shown, the flow-slowing channel 24 is provided with multiple flow-slowing holes 25. The flow-slowing channels 24 of the third-stage flow-slowing plate 22 and the fourth-stage flow-slowing plate 23 are located on opposite sides of the air guide shroud 2. This arrangement can extend the flow path of air from the second-stage flow-slowing cavity 29 into the third-stage flow-slowing cavity 210 and out through the second air duct, further achieving flow-slowing and noise reduction, and significantly reducing the noise when air is discharged from the exhaust duct.

[0068] In a preferred example, such as Figures 4 to 6 As shown, the third-stage flow modulator 22 and the fourth-stage flow modulator 23 are positioned at the same height on the air guide shroud 2. In other words, the third-stage flow modulator 22 and the fourth-stage flow modulator 23 are located at the same axial height on the air guide shroud 2 and extend circumferentially along the air guide shroud 2 to form an annular plate. The flow-modulating channels 24 of the third-stage flow modulator 22 and the fourth-stage flow modulator 23 are located on opposite sides of the radial direction of this annular plate to extend the airflow path. Furthermore, the axial dimension of the air guide shroud 2 can be further compressed, achieving a compact structural layout, thereby further miniaturizing the noise reduction structure.

[0069] As a preferred embodiment of this implementation, such as Figures 3 to 5As shown, the second air duct is provided with an exhaust chamber 213 located downstream of the K-th stage slow flow chamber and connected to the outside. The noise reduction structure also includes a guide baffle 212 for separating the exhaust chamber 213 and the K-1 stage slow flow chamber. The height of the guide baffle 212 extending along the axial direction of the fan 1 is greater than the height of the K-1 stage slow flow chamber, so that the projection of the exhaust chamber 213 along the axial direction of the fan 1 at least partially overlaps with the projection of the K-2 stage slow flow chamber along the axial direction of the fan 1.

[0070] In a specific example, such as Figures 4 to 6 As shown, the first air duct has three stages of flow-damping plates, while the second air duct has one stage. For ease of description, the flow-damping plates in the first air duct are defined as primary plate 26, second-stage flow-damping plate 21, and third-stage flow-damping plate 22, and the flow-damping plate in the second air duct is defined as fourth-stage flow-damping plate 23. The second-stage flow-damping plate 21 and the third-stage flow-damping plate 22 are arranged sequentially along the axis of the air guide hood 2 to divide the space within the air guide hood 2 into a first-stage flow-damping cavity 28, a second-stage flow-damping cavity 29, and a third-stage flow-damping cavity 210. The third-stage flow-damping plate 22 in the first air duct and the fourth-stage flow-damping plate 23 in the second air duct are located on opposite sides of the air guide hood 2, and the third-stage flow-damping cavity 210 connects the first and second air ducts. The exhaust cavity 213 is located downstream of the third flow-damping cavity 210, and the baffle 212 separates the exhaust cavity from the second-stage flow-damping cavity 29. The height of the guide baffle 212 extending along the circumference of the fan 1 is greater than the height of the second-stage slow-flow cavity 29, so that the projection of the exhaust cavity 213 along the axial direction of the fan 1 at least partially overlaps with the projection of the first-stage slow-flow cavity 28 along the axial direction of the fan 1.

[0071] By extending the height of the guide baffle 212, the exhaust cavity 213 can occupy the dimensions of the first-stage slow-flow cavity 28 and the second-stage slow-flow cavity 29 in the axial direction of the guide hood 2. This makes full use of the axial dimensions of the guide hood 2, allowing the volume of the exhaust cavity 213 to be expanded within a limited space, further reducing the flow velocity when the air is discharged and improving the noise reduction effect.

[0072] As a preferred embodiment of this application, such as Figure 1 , Figure 2 , Figure 3 and Figure 7As shown, the noise reduction structure also includes a sealing cover 4 mounted above the air guide shroud 2. The sealing cover 4 and the air guide shroud 2 cooperate to form a sealed cavity 5. The air guide shroud 2 is provided with a silencer hole 218 connecting the sealed cavity 5 and the first air duct. The setting of the sealing cover 4 and the sealed cavity 5 can reduce the transmission of noise from the fan 1 during operation. On the other hand, by setting the silencer hole 218 connecting the sealed cavity 5 and the first air duct, the two can work together to form a low-frequency silencer. This allows the noise and vibration of the airflow flowing in the first air duct to be reflected and refracted before entering the sealed cavity 5 through the silencer hole 218, thereby improving the noise reduction effect.

[0073] Furthermore, the air guide shroud 2 is provided with several sound-absorbing holes 218 at intervals along its circumference, providing multiple channels and paths for the reflection and refraction of sound waves into the sealed cavity 5, thereby further improving the sound absorption effect.

[0074] As a preferred embodiment of this application, such as Figure 3 As shown, the air guide hood 2 is provided with a ventilation area 27 that connects the air outlet and the exhaust channel, and an exhaust cavity 213 that connects the exhaust channel to the outside. The projections of the ventilation area 27 and the exhaust cavity 213 along the axial direction of the fan 1 at least partially overlap, thereby further reducing the axial dimension of the noise reduction structure on the basis of extending the airflow path, realizing the miniaturization of the noise reduction structure, which in turn helps to miniaturize the surface cleaning device.

[0075] As a preferred embodiment of this application, such as Figure 3 As shown, the air guide hood 2 is provided with a ventilation area 27 connecting the air outlet and the exhaust channel, and an exhaust cavity 213 connecting the exhaust channel to the outside. The projections of the ventilation area 27 and the exhaust cavity 213 along the radial direction of the fan 1 are located on two opposite sides of the axis of the fan 1, thereby further extending the flow path of the airflow from the air inlet end of the exhaust channel to the air outlet end of the exhaust channel. At the same time, it can further optimize the structural layout of the noise reduction structure, making it more compact, which helps to miniaturize the noise reduction structure and thus helps to achieve miniaturization of the surface cleaning device.

[0076] As a preferred embodiment of this application, such as Figure 1 and Figure 3As shown, the air guide hood 2 has an exhaust chamber 213 connecting the second air duct to the outside. An air guide plate 217 is installed inside the exhaust chamber 213. The air guide plate 217 is configured to guide the airflow towards a third direction, which is arranged at an angle to the second direction. The air guide plate 217 can more effectively guide the airflow out of the exhaust chamber 213, reducing airflow stagnation within the exhaust chamber 213 and improving exhaust efficiency. The angled arrangement of the third and second directions allows for airflow reversal during exhaust, further extending the airflow path and improving noise reduction. Furthermore, the third direction is perpendicular to the second direction to further reduce flow velocity and exhaust noise.

[0077] The air guide cover 2 in this application includes a noise reduction cover covering the outside of the fan 1 and an outer shell 216 covering the outside of the noise reduction cover. The noise reduction cover and the outer shell 216 can be formed separately or integrally.

[0078] As a preferred embodiment of this application, such as Figure 3 As shown, the noise reduction mechanism also includes a vibration damping member 3 sandwiched between the fan 1 and the noise reduction cover. By providing the vibration damping member 3, vibration reduction is achieved, further improving the noise reduction effect. Furthermore, the vibration damping member 3 has a vibration damping structure 31 that protrudes towards the inner wall of the noise reduction cover to abut against the inner wall. The vibration damping structure can be, for example, a vibration damping ring extending circumferentially along the vibration damping member 3. Preferably, multiple vibration damping rings are spaced apart along the axial direction of the vibration damping member 3. The vibration damping structure 31 can also be, for example, a plurality of vibration damping protrusions provided on the vibration damping member 3.

[0079] As a preferred embodiment of this application, such as Figure 2 , Figure 4 and Figure 5 As shown, the noise reduction cover includes a primary cover 214 and a secondary cover 215 that overlap sequentially along the axial direction of the air guide cover 2. The primary cover 214 is provided with a primary plate 26 and a second-stage flow-damping plate 21. The secondary cover 215 is provided with a third-stage flow-damping plate 22 and a fourth-stage flow-damping plate 23. A first-stage flow-damping cavity 28 is formed between the primary cover 214 and the outer cover 216. The second-stage flow-damping cavity 29 and the third-stage flow-damping cavity 210 are both formed between the secondary cover 215 and the outer cover 216. By designing the noise reduction cover as a separate unit, the processing difficulty of the flow-damping channel 24 and flow-damping hole 25 on the noise reduction cover and each stage flow-damping plate is reduced.

[0080] It should be noted that the noise reduction structure of the fan 1 in this application also provides a reference for the noise reduction design of other equipment types using the fan 1.

[0081] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0082] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0083] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A fan noise reduction structure for a surface cleaning device, comprising an air guide shroud covering the outside of the fan, wherein the air guide shroud has an exhaust channel connecting the fan outlet to the outside, characterized in that, The exhaust air passage includes a first air duct and a second air duct arranged in sequence along the air flow direction. The first air duct is configured to guide the air flow in a first direction, and the second air duct is configured to guide the air flow in a second direction opposite to the first direction. A plurality of flow retardation plates are provided in the exhaust air passage, and the number of flow retardation plates in the first air duct is greater than the number of flow retardation plates in the second air duct.

2. The fan noise reduction structure for a surface cleaning device according to claim 1, characterized in that, Flow retardation channels are provided on the flow retardation plates. At least two levels of the flow retardation plates extend radially outward along the radial direction of the fan, and the flow retardation channels on adjacent two levels of the flow retardation plates are at least partially staggered in the circumferential direction around the axis of the fan.

3. The fan noise reduction structure for a surface cleaning device according to claim 1, characterized in that, Flow retardation channels are provided on the flow retardation plates. The flow retardation plate includes a primary plate extending along the axial direction of the fan, and the primary plate is provided at the air inlet of the exhaust air passage. The air flow enters the first air duct from the flow retardation channel of the primary plate.

4. The fan noise reduction structure for a surface cleaning device according to claim 1, characterized in that, It is characterized in that It further includes a diversion baffle connected to the flow retardation plate. The diversion baffle jointly forms the side walls of the first air duct and the second air duct. At least part of the flow retardation plates arranged at intervals along the axial direction of the fan overlap with the projection of the diversion baffle.

5. The fan noise reduction structure for a surface cleaning device according to claim 1, characterized in that, A flow retardation cavity is formed between adjacent two levels of the flow retardation plates. The number of levels of the flow retardation cavity is K, and K is an integer greater than or equal to 3. Among them, a partition is provided in the Mth-level flow retardation cavity to divide it into a plurality of diversion cavities. The air flow is diverted from the (M - 1)th-level flow retardation cavity into the diversion cavities and then converges in the (M + 1)th-level flow retardation cavity, where 1 < M < K and M is an integer.

6. The fan noise reduction structure for a surface cleaning device according to claim 5, characterized in that, The number of flow retardation plates in the first air duct is three levels, and the number of flow retardation plates in the second air duct is one level. The third-level flow retardation plate in the first air duct and the fourth-level flow retardation plate in the second air duct are分立 on opposite sides of the air guide cover. The third-level flow retardation cavity communicates with the first air duct and the second air duct. Among them, the first direction is downward, and the second direction is upward.

7. A fan noise reduction structure for a surface cleaning device according to claim 5, characterized in that, characterized in that An exhaust air cavity communicating with the outside is provided in the second air duct on the downstream side of the Kth-level flow retardation cavity. The noise reduction structure further includes a diversion baffle for separating the exhaust air cavity and the (K - 1)th-level flow retardation cavity. The height of the diversion baffle extending along the axial direction of the fan is greater than the height of the (K - 1)th-level flow retardation cavity, so that the projection of the exhaust air cavity along the axial direction of the fan at least partially overlaps with the projection of the (K - 2)th-level flow retardation cavity along the axial direction of the fan.

8. A fan noise reduction structure for a surface cleaning device according to claim 1, characterized in that The air guide shroud has a ventilation area connecting the air outlet and the exhaust duct, and an exhaust cavity connecting the exhaust duct to the outside. The projections of the ventilation area and the exhaust cavity along the axial direction of the fan at least partially overlap. 。 9. A fan noise reduction structure for a surface cleaning device according to claim 1, characterized in that, The air guide cover is provided with an exhaust air cavity communicating with the outside. A guide air plate is provided in the exhaust air cavity, and the guide air plate is configured to guide the air flow to flow in a third direction. The third direction is arranged at an angle with the second direction.

10. A fan noise reduction structure for a surface cleaning device according to claim 1, characterized in that, The noise reduction structure further includes a sealing cover covering the upper part of the air guide cover. The sealing cover and the air guide cover cooperate to enclose a sealing cavity. The sealing cavity is communicated with the first-level flow retardation cavity of the first air duct through a sound absorption hole. It should be noted that the word "分立" in the original text seems to be incorrect or an uncommon expression. I translated it as "分立" as it is in the original, but it might need to be further verified or corrected in the context.

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