A flexible, encapsulated fan assembly and a window cleaning robot using it.

Abstract

This utility model discloses an elastically enclosed fan assembly and a window cleaning robot using the same. The fan assembly includes an upper shell, an elastic lower shell, and a fan support disposed within the air cavity formed by the two. The fan support supports the drive unit and fan blades, and the lower shell secures the fan support through its own elastic restoring force. This utility model fundamentally changes the rigid connection method of traditional fan assemblies by using an elastic lower shell to fix the fan support. The elastic lower shell achieves reliable fixation while also providing damping and vibration isolation functions, effectively blocking the path of vibration from the drive unit to the outer shell, thereby significantly suppressing structural resonance and reducing operating noise. Furthermore, this connection method, which requires no additional fasteners, simplifies the assembly process and reduces production costs.

Description

[Technical Field] This utility model relates to the field of window cleaning robot technology, and in particular to an elastically wrapped fan assembly and a window cleaning robot using the same. [Background Technology] Window cleaning robots are a rapidly developing smart home appliance product in recent years. They typically use a built-in fan assembly to generate negative pressure, allowing them to adhere to vertical surfaces such as glass and move autonomously to perform cleaning tasks. The fan assembly, as the core component enabling its suction function, needs to provide continuous and powerful airflow suction within a compact size.

[0003] However, existing window cleaning robots often generate significant operating noise and structural vibration from their fan components during operation, which has become a common technical problem affecting user experience and hindering product promotion. Traditional fan components, such as the fan bracket and housing, are rigid parts, typically connected by screws or clips. When the built-in drive motor rotates at high speed, its own vibrations are transmitted without attenuation to the entire component and even the robot body through this rigid connection path, causing structural resonance and generating unpleasant low-to-mid-frequency structural noise. [Utility Model Content] The purpose of this utility model is to provide an elastically enclosed fan assembly and a window cleaning robot using it, aiming to solve the technical problem that the internal components of the existing fan assembly are mostly rigidly connected, which causes the vibration generated by the drive motor to be directly transmitted to the outer shell, resulting in structural resonance and large operating noise.

[0005] This utility model is achieved through the following technical solution: A flexible enclosed fan assembly includes an upper housing with an air outlet channel, the upper housing being connected to a flexible lower housing that defines an internal air cavity, the lower housing having an air inlet at its bottom, a fan bracket being enclosed on the inner wall of the lower housing, a drive device being provided above the fan bracket, and a fan blade being provided below the fan bracket, connected to the drive device and used to draw airflow from the air inlet into the air cavity, wherein the lower housing is fixed to the fan bracket by its own elastic restoring force.

[0006] As described above, in the elastically enclosed fan assembly, the inner wall of the lower housing is provided with a first docking groove for radial and circumferential positioning of the bottom of the fan bracket, and the lower end of the fan bracket is provided with a first docking part that mates with the first docking groove.

[0007] As described above, in the elastically enclosed fan assembly, the top of the lower housing is provided with a second docking portion, and the bottom of the upper housing is provided with a second docking groove that matches the second docking portion.

[0008] As described above, the elastically enclosed fan assembly has a stepped portion on the outer side of the second docking portion. After the upper housing, the lower housing, and the fan bracket are assembled, the outer side of the lower end of the upper housing abuts against the stepped portion, and the inner side of the lower end of the upper housing abuts against the upper end of the fan bracket.

[0009] As described above, in the elastically enclosed fan assembly, the upper and lower edges of the fan bracket are tightly aligned with the inner walls of the upper and lower housings after assembly, so as to form a smooth and continuous transition surface at the connection of the three components in the air cavity.

[0010] As described above, the flexible enclosed fan assembly has multiple rectification structures on the fan support for rectifying the rotating airflow with a tangential velocity component generated from the fan blades, thereby reducing the tangential velocity component of the rotating airflow.

[0011] As described above, in the elastically enclosed fan assembly, the rectifying structure consists of multiple integrally formed and annularly arrayed guide ribs, with air holes for airflow between any two adjacent guide ribs.

[0012] As described above, in the elastically enclosed fan assembly, the lower end of the guide rib has a smooth leading edge for smoothly separating the airflow, and the guide rib gradually narrows upward from the smooth leading edge, and the upper end has an angular trailing edge for stabilizing the airflow separation point.

[0013] In the elastically encased fan assembly described above, the material of the lower housing is selected from at least one of thermoplastic elastomer, silicone, polypropylene, or EPDM rubber.

[0014] A window cleaning robot includes a flexible, enclosed fan assembly as described above.

[0015] Compared with the prior art, the present invention has the following advantages: This invention fundamentally changes the traditional rigid connection method of fan components by employing a flexible lower shell and utilizing its own elastic restoring force to fix the fan support bearing the vibration source (drive device). The flexible lower shell achieves reliable fixation while also providing damping and vibration isolation, effectively blocking the rigid path of vibration transmission from the drive device to the outer shell, thereby significantly suppressing structural resonance and achieving the beneficial effects of reducing overall machine operating noise and improving user experience. Furthermore, this connection method, which requires no additional fasteners, greatly simplifies the assembly process, reduces the number of parts, effectively lowers production costs, and improves the long-term reliability of the product. [Attached Image Description] To more clearly illustrate the technical solutions in the embodiments of the utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0017] Figure 1 This is a schematic diagram of the three-dimensional structure of this embodiment. Figure 1 ; Figure 2 This is a schematic diagram of the three-dimensional structure of this embodiment. Figure 2 ; Figure 3 This is a top view of this embodiment; Figure 4 This is a schematic diagram of the exploded structure of this embodiment. Figure 1 ; Figure 5 This is a schematic diagram of the exploded structure of this embodiment. Figure 2 ; Figure 6 for Figure 3 Sectional view along line AA; Figure 7 for Figure 3 Sectional view along line BB; Figure 8 for Figure 6 A magnified schematic diagram of the change in airflow direction at point C; Figure 9 This is a three-dimensional structural diagram of the lower shell in this embodiment; Figure 10 This is a schematic diagram of the front cross-section of the lower shell in this embodiment; Figure 11 This is a three-dimensional structural diagram of the wind turbine support in this embodiment.

Detailed Implementation Methods

[0018] Example 1: This embodiment provides a flexible, enclosed fan assembly, which serves as a core negative pressure component and is particularly suitable for intelligent cleaning equipment such as window cleaning robots. The conventional function of this fan assembly is to generate a stable and strong negative pressure, enabling the device mounted on it to reliably adhere to a vertical working surface.

[0019] However, existing window cleaning robots often generate significant operating noise and structural vibration from their built-in fan components during operation, which has become a common technical problem affecting user experience and hindering product promotion. A large portion of this noise and vibration originates from the high-speed rotation of the drive motor and the resonance caused by the rigid connections between various hard components. This embodiment aims to solve the aforementioned noise and vibration problems by employing an innovative structural design to suppress vibration and noise at their source.

[0020] Please see the appendix Figures 1 to 11 The basic structure of the fan assembly includes an upper shell 2, a lower shell 3, a fan bracket 6, a drive unit 7, and fan blades 8.

[0021] Specifically, the lower housing 3 has an air inlet 5 at its bottom center for drawing in air from the outside. The upper housing 2 and the lower housing 3 together define an internal air cavity 4 for accommodating other components and guiding airflow. One or more air outlet channels 1 are also provided on the upper housing 2 for discharging the airflow from the air cavity 4. The fan bracket 6, as a key load-bearing component, is fixedly installed inside the air cavity 4. A drive unit 7, such as a drive motor, is mounted and fixed to the upper part of the fan bracket 6. A fan blade 8, connected to the output shaft of the drive unit 7, is located below the fan bracket 6. When the drive unit 7 operates, it drives the fan blade 8 to rotate at high speed, generating a strong suction force that draws air in from the air inlet 5 and forces it upwards into the air cavity 4.

[0022] The core of this embodiment lies in the unique elastic fixing relationship formed between the lower housing 3 and the fan support 6. The fan support 6 can be made of rigid polymer materials, such as ABS, PC, or glass fiber reinforced PBT, to ensure sufficient structural rigidity to stably support the drive unit 7 and the fan blades 8. The lower housing 3, on the other hand, is made of an elastic material, which fixes the fan support 6 through its own elastic restoring force. Functionally, the fixing relationship between the lower housing 3 and the fan support 6 is a kind of elastic enclosure. The term "enclosure" here is intended to describe a pre-stressed state in which the lower housing 3 actively applies force to the fan support 6, and should not be narrowly interpreted as a complete geometrical enclosure. Specifically, this enclosure can be achieved through various structural forms: One option is a continuous surface-contact covering. In this alternative embodiment, the diameter of the inner wall of the lower housing 3 is designed to be slightly smaller than the outer diameter of the rigid fan bracket 6 in the free state, forming an interference fit between the two.

[0023] Secondly, the covering can also be partial or discontinuous. In some alternative solutions, multiple circumferential or axial elastic ribs, protrusions, or other protrusions can be integrally formed on the inner wall of the lower housing 3. In these solutions, only these elastic protrusions make interference contact with the outer wall of the wind turbine support 6. After assembly, the lower housing 3 also applies a continuous, distributed radial clamping force to the wind turbine support 6 through these local contact points, thus achieving a stable elastic covering fixation.

[0024] Corresponding to the above structure, its assembly process is not limited to a single method. Its fundamental purpose is to place the rigid fan bracket 6 into the lower housing 3 by causing elastic deformation, and finally use the elastic potential energy stored in the lower housing 3 to complete the fixation.

[0025] One optional assembly method is direct press-fit. This involves using external tooling to apply axial pressure, forcibly pushing the fan bracket 6 into the lower housing 3, which has a slightly smaller inner diameter. During this process, the opening or inner wall of the lower housing 3 is temporarily stretched open, undergoing elastic deformation. Once the fan bracket 6 reaches the predetermined position, the elastic restoring force of the lower housing 3 tightly locks it in place.

[0026] Another optional assembly method is pre-expansion insertion. During assembly, a special clamp can be used to briefly and controllably expand the opening of the lower housing 3 from the outside, temporarily making its inner diameter larger than the outer diameter of the fan bracket 6. Then, the fan bracket 6 can be easily placed into the predetermined position of the lower housing 3. Finally, the clamp is removed, and the lower housing 3 instantly contracts due to elastic recovery, and its inner wall or internal elastic structure firmly abuts and holds the fan bracket 6.

[0027] In summary, this embodiment, through the ingenious combination of rigid and elastic components, eliminates the need for traditional screws, glue, or complex snap-fit ​​structures, greatly simplifying the assembly process and reducing production costs. More importantly, the lower housing 3, as an elastic body, itself constitutes a highly efficient, all-around damping structure, effectively absorbing and buffering the vibrations generated by the drive unit 7 and the fan blades 8 during operation, thereby achieving significant vibration reduction and noise reduction effects.

[0028] To effectively achieve the aforementioned elastic fixation and vibration reduction / noise reduction functions, in this embodiment, the material of the lower housing 3 can be at least one selected from thermoplastic elastomers, silicone, polypropylene, or EPDM rubber. Each material selection corresponds to different performance focuses and cost considerations: Alternatively, when a thermoplastic elastomer (TPE) is used, the lower housing 3 achieves excellent overall performance. This type of material combines the high elasticity of rubber with the easy processability of plastics, allowing for rapid and precise molding using conventional injection molding processes. Its excellent resilience ensures a long-term and stable clamping force on the wind turbine support 6, while its superior damping characteristics make it an ideal choice for absorbing vibration energy and reducing structural resonance.

[0029] Optionally, when silicone, especially silicone rubber, is used, the lower housing 3 provides reliable performance assurance. Silicone rubber generally outperforms most thermoplastic elastomers in fatigue and creep resistance, meaning that its elastic recovery is not easily diminished even under long-term pressure and temperature changes, ensuring durable sealing and fixing force. Furthermore, its excellent high and low temperature resistance and chemical stability allow this fan assembly to adapt to more demanding working environments, such as near windows in direct sunlight or in contact with various cleaning agents, which is significant for improving the long-term reliability of products such as window cleaning robots.

[0030] Alternatively, when ethylene propylene diene monomer (EPDM) rubber is used, the lower shell 3 offers significant advantages in terms of weather resistance. EPDM rubber is renowned for its excellent resistance to UV radiation and ozone aging, making it ideal for products that may be exposed to strong sunlight, such as near windows, for extended periods. It also possesses excellent elasticity and durability.

[0031] Alternatively, when using common rigid or semi-rigid engineering plastics such as polypropylene (PP), the lower housing 3 offers advantages in cost control and broad applicability. In this design, the elasticity of the lower housing 3 is primarily achieved through structural design, such as by thinning its wall thickness or designing a specific elastic arm structure, enabling it to generate sufficient deformation to assemble and fix the wind turbine bracket 6. Of course, those skilled in the art will understand that achieving the aforementioned elastic restoring force fixation effect is not limited to the specific materials mentioned above. Any polymeric material with suitable elastic modulus and fatigue resistance properties can be used as a candidate material for the lower housing 3.

[0032] Furthermore, in order to ensure that the wind turbine support 6, which is fixed by elastic restoring force, can maintain accurate and stable spatial posture when subjected to the reverse torque of the drive device 7 during start-up and shutdown, as well as long-term vibration, this embodiment also provides an auxiliary positioning and support structure.

[0033] Specifically, a first mating groove 31 for precisely positioning the bottom of the fan bracket 6 radially and circumferentially is integrally formed on the bottom of the inner wall of the lower housing 3, surrounding the air inlet 5. As an optional embodiment, this first mating groove 31 is designed as a continuous, complete annular inner groove. Correspondingly, a first mating portion 61, capable of precisely engaging with the annular inner groove, is integrally formed at the lower end of the rigid fan bracket 6. Structurally, this first mating portion 61 is an annular extension or annular flange extending downward from the lower edge of the fan bracket 6.

[0034] During assembly, the annular first mating part 61 of the fan bracket 6 is precisely embedded into the annular first mating groove 31 at the bottom of the lower housing 3. This full-circumferential contact fit between annular surfaces brings several significant technical advantages. First, the annular structure itself has a natural centering effect, ensuring that the central axis of the fan bracket 6 is highly aligned with the central axis of the lower housing 3. This is crucial for ensuring the stable and efficient rotation of the fan blades 8 within the air cavity 4, and for avoiding additional vibration and noise caused by eccentricity.

[0035] Secondly, since the first docking part 61 and the first docking groove 31 mesh with each other on the entire circumference, rather than at a few discrete points, it can effectively resist the reverse impact torque generated by the drive device 7 at the moment of starting and stopping, thus preventing the fan bracket 6 from rotating circumferentially at any angle.

[0036] Furthermore, this structure provides a stable and solid support base for the entire wind turbine bracket 6, which can effectively resist tilting or shaking that may be caused by equipment movement or bumps, ensuring the structural integrity of the wind turbine components and the reliability of long-term operation.

[0037] Furthermore, to achieve a stable, reliable, and airtight connection between the upper shell 2 and the elastic lower shell 3, this embodiment also incorporates a docking structure at the upper interface. Specifically, a second docking portion 32 extending upwards is integrally formed at the top opening edge of the elastic lower shell 3. As an optional feature of this embodiment, the second docking portion 32 is designed as a continuous, complete annular vertical wall. Correspondingly, a second docking groove 21, which precisely matches the annular vertical wall, is formed at the bottom of the rigid upper shell 2. This docking groove is also structurally a continuous annular groove. During assembly, the second docking portion 32 at the top of the lower shell 3 is vertically inserted into the annular second docking groove 21 at the bottom of the upper shell 2, forming a plug-in sealing structure. This design also possesses several significant technical advantages. First, the second docking portion 32 and the second docking groove 21 provide natural guidance and centering during assembly, ensuring that the upper and lower shells can be quickly and accurately aligned coaxially, avoiding assembly misalignment.

[0038] Secondly, when the elastic second mating part 32 is pressed into the rigid second mating groove 21, its outer and inner walls will undergo elastic deformation due to compression, thereby tightly fitting with the inner and outer walls of the second mating groove 21 to form two reliable annular sealing surfaces. This is crucial for preventing high-pressure gas in the air cavity 4 from leaking from the shell joint and is key to ensuring the negative pressure efficiency of the fan assembly.

[0039] Furthermore, the plug-in structure provides effective mechanical restraint in both the vertical and parallel directions of the axis, preventing radial misalignment or tilting between the upper and lower housings, thus greatly enhancing the structural integrity and impact resistance of the entire wind turbine assembly housing.

[0040] Alternatively, as an optional enhanced sealing solution, sealant can be applied or an independent sealing element such as an O-ring can be added at the mating interface between the second mating part 32 and the second mating groove 21 to achieve ultimate airtight performance.

[0041] Furthermore, to enhance the locking strength of the overall structure, a stepped portion 33 is provided on the outer circumferential side of the second mating portion 32. This stepped portion 33 provides a precise axial reference plane for the final assembly of the entire wind turbine assembly. Please refer to the appendix for details. Figure 7 , Figure 10When the upper housing 2 is finally assembled and pressed downwards, its bottom second mating groove 21 not only fits over the second mating portion 32 of the lower housing 3, but its inner and outer walls also play a crucial role in applying axial pressure. Specifically, the lower edge of the outer wall of the second mating groove 21 continues to descend until its end face is fully in contact with and abuts against the upper surface of the stepped portion 33 on the lower housing 3. This contact provides a rigid axial support between the upper and lower housings, precisely defining their final assembly depth. At the same time, the lower edge of the inner wall of the second mating groove 21 also descends synchronously, and finally comes into full contact with the upper edge of the rigid fan bracket 6, which has been pre-installed inside the lower housing 3, and applies downward pressure.

[0042] Through this collaborative design, the upper housing 2 acts like a pressure cap, simultaneously pressing down on two independent components: its outer side (through the outer wall of the second mating groove 21) presses down on the lower housing 3 (through the step portion 33); its inner side (through the inner wall of the second mating groove 21) presses down on the fan bracket 6. Optionally, to generate and maintain this crucial axial pressure, a locking structure (not shown in the figure) can also be provided between the upper housing 2 and the lower housing 3. Specifically, mutually mating screw holes and screws can be provided on the outer walls of the upper housing 2 and the lower housing 3, or an integrally formed elastic buckle and slot can be provided. When the upper and lower housings are pulled closer together axially and finally locked by tightening the screws or engaging the buckle, the aforementioned downward pressure is stably applied and maintained.

[0043] This double-locking structure ensures that the fan bracket 6 is firmly clamped between the first mating groove 31 at the bottom of the lower housing 3 and the pressure between the top of the upper housing 2, eliminating the possibility of axial movement. Simultaneously, the upper and lower housings are rigidly connected via the stepped portion 33. Ultimately, the three components are tightly integrated into a single unit, significantly enhancing the product's structural strength and impact resistance, and creating the prerequisites for suppressing structural resonance and achieving quiet operation of the entire machine.

[0044] Furthermore, as an optional implementation, in a preferred embodiment, the upper and lower edges of the fan bracket 6 are tightly aligned with the inner walls of the upper housing 2 and the lower housing 3 after assembly, respectively. This allows the three independent physical components to form a smooth and continuous transition surface at their connecting joints. The core idea of ​​this design is to treat the inner wall of the air cavity 4 as a whole aerodynamic surface, eliminating steps, gaps, or sharp corners caused by component assembly tolerances in traditional designs. This fundamentally eliminates flow separation points at component connections, avoids the generation of local turbulence and eddies, and provides a guarantee for achieving ultimate quietness and improving aerodynamic efficiency.

[0045] Furthermore, as an optional implementation, multiple rectifying structures 62 are integrally formed on the fan support 6, downstream of the airflow of the fan blade 8. The airflow discharged from the fan blade 8, due to its high-speed rotation, not only has axial velocity but also carries a strong tangential velocity component, thus forming a rotating airflow. This rotating airflow is the main source of vortices and high-frequency aerodynamic noise. The rectifying structure 62 in this embodiment does not primarily guide the airflow, but actively and forcibly rectifyes this rotating airflow. Through interaction with the airflow, it effectively reduces its tangential velocity component, disrupting the conditions for vortex formation at its source, thereby achieving a significant noise reduction effect and making the wind feel smoother.

[0046] Furthermore, as a preferred embodiment, the rectifying structure 62 specifically comprises a plurality of annularly arrayed guide ribs 621. These guide ribs 621 are integrally formed on the fan bracket 6, resulting in high structural strength and good production consistency. Between any two adjacent guide ribs 621, air holes 622 are naturally defined for airflow to pass through. After being accelerated by the fan blades 8, the airflow will pass through these air holes 622.

[0047] Furthermore, to maximize the rectification and noise reduction effect, this embodiment features a special aerodynamic design for the cross-sectional profile of the guide rib 621. Please refer to the appendix for details. Figure 8 , Figure 11The guide rib 621 has a streamlined cross-section that is symmetrical along its central axis but has different front and rear contours along the airflow direction. Specifically, the lower end of the guide rib 621, i.e., the side facing the airflow impact, has a smooth leading edge 6211 for smoothly separating the airflow. When the high-speed airflow impacts this smooth leading edge 6211, it can be smoothly separated to both sides, avoiding the violent pressure pulsation and impact noise caused by the head-on collision of the airflow with the blunt body. Subsequently, the rib of the guide rib 621 gradually narrows upward from the smooth leading edge 6211, and forms a angular trailing edge 6212 at its upper end for stabilizing the airflow separation point. This structure allows the airflow flowing around the rib to form a stable and clear separation point at the angular trailing edge 6212, greatly suppressing the wake vortex formed behind the rib due to the alternating shedding of airflow, thereby further reducing fluid noise. Of course, those skilled in the art will understand that the above-mentioned technical effects of smooth flow separation and wake suppression are not limited to the specific cross-sectional shape mentioned above. Based on the core concept of this application, there are several other feasible cross-sectional profile options. For example, in some alternatives, the cross-section of the guide rib 621 can be designed as a standard ellipse, with its major axis aligned along the axial direction of the airflow, i.e., parallel to the central rotation axis of the fan blade 8. Preferably, a high-eccentricity ellipse with a large ratio between its major and minor axes can be used. This configuration allows the guide rib to present the narrowest windward face and a smooth flow profile to the main axial airflow, thereby greatly reducing form drag; while its thickness along the minor axis effectively impedes and regulates the lateral rotating airflow. Its perfectly smooth surface can minimize frictional and pressure drag when the airflow contacts the rib. Compared to angular shapes, the elliptical cross-section can better maintain the boundary layer adhesion state, delaying the occurrence of airflow separation points, thereby effectively reducing broadband turbulent noise and resulting in a cleaner overall wind noise.

[0048] Furthermore, as a preferred embodiment, the extension direction of the plurality of guide ribs 621 is set to be parallel to the central rotation axis of the fan blade 8. This axially parallel arrangement makes the ribs of each guide rib form a direct obstruction surface for the tangential velocity component of the rotating airflow, which can effectively cut and block the rotating airflow, forcibly changing its motion direction from tangential to axial, thereby achieving a highly efficient rectification effect.

[0049] This arrangement differs fundamentally from the commonly used spiral or inclined guide structures in existing technologies. The latter are designed to follow the rotational trend of the airflow and smoothly change its flow path through an inclined guide surface; while the axial parallel layout of this embodiment aims to actively and forcibly eliminate the rotational component of the airflow through direct obstruction and segmentation, thereby suppressing the generation of vortices at the source.

[0050] Furthermore, as an alternative, the rectifying structure 62 can be a honeycomb rectifier (not shown in the figure). Specifically, the honeycomb rectifier can be an integral, disc-shaped, or annular structure with a large number of axially parallel microchannels with small apertures running through it. The cross-section of these channels can be hexagonal, quadrilateral, or circular. This rectifier is also fixedly positioned downstream of the airflow of the fan blade 8. When the high-speed rotating airflow impacts this structure, it is forcibly divided into hundreds of tiny airflows that enter these parallel microchannels. Under the constraint of the channel walls, the rotational kinetic energy of the airflow is rapidly dissipated, and each tiny airflow, upon leaving the channel, is directed into a straight flow parallel to the channel axis. In this way, effective rectification of the rotating airflow is achieved, reducing eddy noise. This honeycomb rectifier can be injection molded from polymer materials or stamped and welded from metal sheets.

[0051] Furthermore, as an alternative, the rectifying structure 62 can also be a multi-stage stator guide ring (not shown in the figure). In this design, the rectification of the rotating airflow is accomplished by at least two fixed blade stages arranged sequentially along the airflow path, achieving a finer, more gradual streamlining of the airflow. Specifically, the fan support 6 itself is designed with a multi-stage guide structure. Specifically, the fan support 6, in a cross-section perpendicular to the airflow direction, is constructed with at least two layers of concentric or series-connected fixed guide blades.

[0052] The first-stage guide vanes (not shown in the figure) are located at the lower part of the fan support 6, that is, downstream of the airflow immediately adjacent to the rotating fan blades 8. These first-stage vanes can be set at a specific tilt angle opposite to the direction of airflow rotation. Their main function is to make the first impact on the high-speed rotating airflow and initially decelerate it, weakening most of its tangential kinetic energy.

[0053] The second-stage guide vanes (not shown in the figure) are located on the upper part of the fan support 6, directly above the first-stage guide vanes. When the airflow, which has undergone initial rectification but still carries some residual rotation and turbulence, continues to flow upward, it will immediately impact the second-stage guide vanes. The tilt angle, curvature, or number of the second-stage guide vanes can differ from the first stage, for example, by using a smaller tilt angle or a denser arrangement, to perform a second, more refined sorting and reverse deflection of the airflow, thereby further eliminating residual rotational components and ensuring that the airflow, when finally leaving the fan support, is essentially a straight axial flow.

[0054] Example 2: This embodiment also provides a window cleaning robot. The window cleaning robot may include conventional components such as a body, motion components, cleaning components, control components, and power supply components. Its innovation lies in the use of a flexible, enclosed fan assembly as described in the preceding embodiments. Due to the excellent vibration and noise reduction performance, smooth internal airflow, and efficient rectification structure of this fan assembly, the window cleaning robot provides strong suction while significantly reducing operating noise compared to existing technologies. This greatly improves the user experience in indoor environments. Furthermore, the improved aerodynamic efficiency means stronger suction or longer battery life at the same power consumption, resulting in significant practical value and a competitive market advantage.

[0055] The above are implementation methods provided in conjunction with specific content, and it is not intended that the specific implementation of this application is limited to these descriptions. Any methods or structures that are similar to those of this application, or any technical deductions or substitutions made based on the concept of this application, should be considered within the scope of protection of this application.

Claims

1. A flexible, enclosed fan assembly, characterized in that, The device includes an upper housing (2) with an air outlet channel (1), the upper housing (2) being connected to a lower housing (3) with elasticity, and the two defining an internal air cavity (4). The lower housing (3) has an air inlet (5) at its bottom. A fan bracket (6) is provided on the inner wall of the lower housing (3). A drive device (7) is provided above the fan bracket (6). A fan blade (8) is provided below the fan bracket (6) and is connected to the drive device (7) for drawing airflow from the air inlet (5) into the air cavity (4). The lower housing (3) fixes the fan bracket (6) with its own elastic restoring force.

2. The elastically encased fan assembly according to claim 1, characterized in that, The inner wall of the lower housing (3) is provided with a first docking groove (31) for radial and circumferential positioning of the bottom of the fan bracket (6), and the lower end of the fan bracket (6) is provided with a first docking part (61) that cooperates with the first docking groove (31).

3. The elastically encased fan assembly according to claim 1, characterized in that, The lower housing (3) has a second docking part (32) at its top, and the upper housing (2) has a second docking groove (21) at its bottom that matches the second docking part (32).

4. The elastically encased fan assembly according to claim 3, characterized in that, The second docking part (32) has a stepped part (33) on its outer side. When the upper shell (2), the lower shell (3) and the fan bracket (6) are assembled, the lower outer side of the upper shell (2) abuts against the stepped part (33), and the lower inner side of the upper shell (2) abuts against the upper end of the fan bracket (6).

5. The elastically encased fan assembly according to claim 4, characterized in that, The upper and lower edges of the fan bracket (6) are closely aligned with the inner walls of the upper housing (2) and the lower housing (3) after assembly, so as to form a smooth and continuous transition surface at the connection of the three in the air cavity (4).

6. The elastically encased fan assembly according to claim 1, characterized in that, The fan support (6) is provided with multiple rectification structures (62) for rectifying the rotating airflow with tangential velocity component generated from the fan blade (8) to reduce the tangential velocity component of the rotating airflow.

7. The elastically encased fan assembly according to claim 6, characterized in that, The rectifying structure (62) consists of multiple integrally formed and circularly arrayed guide ribs (621), with air holes (622) for airflow to pass through between any two adjacent guide ribs (621).

8. The elastically encased fan assembly according to claim 7, characterized in that, The lower end of the guide rib (621) has a smooth leading edge (6211) for smooth separation of airflow. The guide rib (621) gradually narrows upward from the smooth leading edge (6211) and has an angular trailing edge (6212) at the upper end for stabilizing the airflow separation point.

9. The elastically encased fan assembly according to claim 1, characterized in that, The material of the lower housing (3) is selected from at least one of thermoplastic elastomer, silicone, polypropylene, or EPDM rubber.

10. A window cleaning robot, characterized in that, Includes a flexible encapsulated fan assembly as described in any one of claims 1-9.

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