Fan and cleaning device

Abstract

This utility model discloses a fan and cleaning equipment, relating to the field of fan technology. The fan includes a housing, at least two impellers, a first drive assembly, and a second drive assembly. The housing has a first air inlet, a cavity, and a first air outlet connected in sequence. At least two impellers are rotatably mounted in the cavity, arranged sequentially from the first air inlet to the first air outlet. Each impeller includes a first impeller and a second impeller. The first drive assembly is connected to the first impeller and drives its rotation. The second drive assembly is connected to the second impeller and drives its rotation. Any second impeller is closer to the first air outlet than any first impeller, and the rotational speed of the second impeller is greater than that of the first impeller. This utility model's fan can increase the rotational speed of the impeller closer to the first air outlet, reduce turbulence, and improve operating efficiency.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and in particular to a fan and cleaning equipment. Background Technology

[0002] Cleaning equipment such as robotic vacuum cleaners and traditional vacuum cleaners are equipped with fans. When the fans are running, they create negative pressure and generate suction. The cleaning equipment uses this suction to pick up dust, hair, and other foreign objects, thus achieving the purpose of cleaning. The strength of the fan's suction affects the cleaning effect of the equipment.

[0003] In related technologies, to improve the suction power of a fan, multiple impellers are used to perform multi-stage compression of the gas, thereby increasing the negative pressure at the fan inlet to enhance suction. Because the gas is compressed sequentially by multiple impellers, the gas pressure increases closer to the outlet. The impeller speed near the outlet cannot match the high-pressure gas, leading to turbulence, reduced impeller efficiency, and ultimately affecting the cleaning effect of the cleaning equipment. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a fan that can increase the rotational speed of the impeller near the first air outlet, reduce turbulence, and improve operating efficiency.

[0005] This utility model also provides a cleaning device having the above-mentioned fan.

[0006] A fan according to a first aspect embodiment of the present invention includes a housing, a first air inlet, a cavity, and a first air outlet connected in sequence; at least two impellers, each rotatably mounted in the cavity, the at least two impellers being arranged sequentially from the first air inlet to the first air outlet, the at least two impellers including a first impeller and a second impeller; a first drive assembly connected to the first impeller and used to drive the first impeller to rotate; a second drive assembly connected to the second impeller and used to drive the second impeller to rotate; wherein any one of the second impellers is closer to the first air outlet than any one of the first impellers, and the rotational speed of the second impeller is greater than the rotational speed of the first impeller.

[0007] The fan according to the first aspect of this utility model has at least the following beneficial effects: A first drive assembly drives a first impeller to rotate, and a second drive assembly drives a second impeller to rotate, with the second impeller rotating at a speed greater than that of the first impeller. This allows gas to be drawn into the cavity from the first air inlet. The first and second impellers sequentially compress the gas, achieving a step-by-step increase in gas pressure. The compressed gas is discharged from the first air outlet, thereby providing the fan with higher suction power. Because the second impeller rotates at a higher speed than the first impeller, as the gas pressure increases, the faster-rotating second impeller can quickly further compress the high-pressure gas, reducing the risk of airflow turbulence caused by high-pressure gas diffusion, i.e., reducing turbulence, reducing airflow loss, and improving the fan's operating efficiency. This is beneficial for increasing the fan's suction power and improving the cleaning effect of the cleaning equipment.

[0008] According to some embodiments of the present invention, the housing includes a first outer shell, a volute, and a second outer shell. The volute connects the first outer shell and the second outer shell. The first outer shell has a first air inlet at one end away from the volute, and the second outer shell has a first air outlet at one end away from the volute. The first impeller is disposed inside the first outer shell, and the second impeller is disposed inside the second outer shell. The volute is used to guide gas from the first outer shell to the second outer shell.

[0009] According to some embodiments of the present invention, the number of blades of at least two of the impellers increases from the first air inlet to the first air outlet.

[0010] According to some embodiments of this utility model, the number of blades of any one of the impellers is N, which satisfies: 7≤N≤13.

[0011] According to some embodiments of the present invention, the number of first impellers is at least two, and the at least two first impellers are arranged sequentially from the first air inlet to the first air outlet. The fan further includes at least one return valve installed in the cavity, and a return valve is provided between two adjacent first impellers. The return valve is used to guide the airflow between two adjacent first impellers; and / or, The number of the second impellers is at least two, and the at least two second impellers are arranged sequentially from the first air inlet to the first air outlet. The fan also includes at least one return valve installed in the cavity. One return valve is provided between two adjacent second impellers. The return valve is used to guide the airflow between two adjacent second impellers.

[0012] According to some embodiments of the present invention, the reflux device includes a plurality of guide vanes, which are arranged at intervals along the central axis of the reflux device. A guide channel is defined between two adjacent guide vanes, and the guide channel is used to guide gas through. The number of guide vanes in any reflux device is coprime to the number of blades in any impeller.

[0013] According to some embodiments of this utility model, the maximum outer diameter of the impeller is D2, and the maximum outer diameter of the reflux device is D3, satisfying: 1.05≤D3 / D2≤1.2.

[0014] According to some embodiments of this utility model, when the number of the first impellers is at least two, the minimum axial spacing between any two adjacent first impellers is L1; the maximum outer diameter of the first impeller is D6, satisfying: 1.27≤D6 / L1≤1.87; When the number of the second impellers is at least two, the minimum axial spacing between any two adjacent second impellers is L2; ​​the maximum outer diameter of the second impeller is D7, satisfying: 1.27≤D7 / L2≤1.87.

[0015] According to some embodiments of the present invention, the housing includes a first inner wall, which is located radially outside the impeller and arranged around the outer periphery of the impeller. The maximum inner diameter of the space surrounded by the first inner wall is D1, and the maximum outer diameter of the impeller is D2, satisfying: 1.25≤D1 / D2≤1.43.

[0016] According to some embodiments of this utility model, the impeller is provided with a second air inlet and a plurality of second air outlets. The second air inlet is located at one axial end of the impeller, and the plurality of second air outlets are located on the outer peripheral wall of the impeller and arranged at intervals along the circumference of the impeller. In any two adjacent impellers, the impeller closer to the first air inlet is the upper stage impeller, and the impeller closer to the first air outlet is the lower stage impeller. The minimum inner diameter of the second air inlet of the upper stage impeller is D4, and the minimum inner diameter of the second air inlet of the lower stage impeller is D5, satisfying: 0.8≤D5 / D4<1.

[0017] According to some embodiments of this utility model, the width of the second air outlet of the upper stage impeller along the axial direction is W1, and the width of the second air outlet of the lower stage impeller along the axial direction is W2, satisfying: 0.6≤W2 / W1≤0.9.

[0018] The cleaning device according to a second aspect of the present invention includes the fan of the first aspect of the present invention.

[0019] The cleaning device according to the second aspect of this utility model has at least the following beneficial effects: Because the cleaning device uses the aforementioned fan, a first impeller is driven to rotate by a first drive assembly, and a second impeller is driven to rotate by a second drive assembly, with the second impeller rotating at a speed greater than that of the first impeller. This allows gas to be drawn into the cavity from the first air inlet. The first and second impellers sequentially compress the gas, achieving a step-by-step increase in gas pressure. The compressed gas is discharged from the first air outlet, thereby giving the fan higher suction power. Since the second impeller rotates at a higher speed than the first impeller, as the gas pressure increases, the faster-rotating second impeller can quickly further compress the high-pressure gas, reducing the risk of airflow turbulence caused by high-pressure gas diffusion, i.e., reducing turbulence, reducing airflow loss, and improving the fan's operating efficiency. This is beneficial for increasing the fan's suction power and improving the cleaning effect of the cleaning device.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the fan structure in an embodiment of this utility model; Figure 2 This is a front sectional view of the fan in an embodiment of this utility model; Figure 3 yes Figure 2 Enlarged view of point A in the middle; Figure 4 This is a schematic diagram of the structure of the first impeller in an embodiment of this utility model; Figure 5 This is a schematic diagram of the reflux device in an embodiment of this utility model; Figure 6 This is a schematic diagram of the diffuser in an embodiment of this utility model.

[0022] Figure label: Housing 100; First air inlet 110; Cavity 120; First inner wall 121; Second inner wall 122; First air outlet 130; First outer shell 140; Volute 150; Second outer shell 160; First impeller 200; blades 210; flow channel 220; second air inlet 230; second air outlet 240; First drive assembly 300; stator 310; rotor 320; shaft 330; Reflux device 400; Flow guide plate 410; Flow guide channel 420; Diffuser 500; Diffuser channel 510; Second impeller 600; Second drive component 700. Detailed Implementation

[0023] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0024] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0025] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0026] In the description of this utility model, unless otherwise explicitly defined, terms such as setting, installing, connecting, assembling, and cooperating should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0027] Cleaning equipment such as robotic vacuum cleaners and traditional vacuum cleaners are equipped with fans. When the fans are running, they create negative pressure and generate suction. The cleaning equipment uses this suction to pick up dust, hair, and other foreign objects, thus achieving the purpose of cleaning. The strength of the fan's suction affects the cleaning effect of the equipment.

[0028] In related technologies, to improve the suction power of a fan, multiple impellers are used to perform multi-stage compression of the gas, thereby increasing the negative pressure at the fan inlet to enhance suction. Because the gas is compressed sequentially by multiple impellers, the gas pressure is higher closer to the outlet. If the impeller rotation speed near the outlet is too low, the high-pressure gas will diffuse, causing turbulence, reducing the impeller's operating efficiency, and affecting the cleaning effect of the cleaning equipment.

[0029] Therefore, referring to Figures 1 to 6As shown, the first aspect of this utility model provides a fan that can be applied to cleaning equipment such as sweeping robots and vacuum cleaners. The cleaning equipment uses the suction generated by the fan to pick up foreign objects such as dust and hair to achieve the purpose of cleaning. Reference Figure 1 and Figure 2 As shown, the fan includes a housing 100, at least two impellers, a first drive assembly 300, and a second drive assembly 700. The housing 100 is provided with a first air inlet 110, a cavity 120, and a first air outlet 130 connected in sequence. The first air inlet 110 is located at one end of the cavity 120, and the first air outlet 130 is located at the other end of the cavity 120.

[0030] Reference Figure 2 As shown, in some embodiments, it can be understood that the impeller includes a first impeller 200 and a second impeller 600, and the number of both the first impeller 200 and the second impeller 600 is two, that is, the total number of impellers is four. The two first impellers 200 and the two second impellers 600 are rotatably mounted within the cavity 120, and are arranged sequentially from the first air inlet 110 through the cavity 120 towards the first air outlet 130. The central axes of the two first impellers 200 are collinear, and the central axes of the two second impellers 600 are also collinear. That is, any one of the second impellers 600 is closer to the first air outlet 130 than any one of the first impellers 200.

[0031] Reference Figure 2 As shown, it can be understood that, in order to guide the airflow between two adjacent first impellers 200 and between two adjacent second impellers 600, the fan also includes two return valves 400. The two return valves 400 are fixedly installed in the cavity 120 of the housing 100. One return valve 400 is disposed between the two first impellers 200, and the central axis of the return valve 400 is collinear with the central axis of the first impeller 200. The other return valve 400 is disposed between the two second impellers 600, and the central axis of the return valve 400 is collinear with the central axis of the second impeller 600.

[0032] Reference Figure 1 and Figure 2As shown, to guide the airflow between adjacent first impeller 200 and second impeller 600, the housing 100 includes a first outer shell 140, a volute 150, and a second outer shell 160, with the volute 150 connected between the first outer shell 140 and the second outer shell 160. The first outer shell 140 and the second outer shell 160 are generally cylindrical in shape and have a central axis. The first outer shell 140 has a first air inlet 110 at its end opposite to the volute 150, and the second outer shell 160 has a first air outlet 130 at its end opposite to the volute 150. The inner cavities of the first outer shell 140, the volute 150, and the second outer shell 160 together form the cavity 120. It is readily understood that gas in the first outer shell 140 enters the volute 150 radially, and gas in the volute 150 enters the second outer shell 160 along the central axis.

[0033] Reference Figure 2 As shown, it can be understood that the two first impellers 200 and the return valve 400 between the two first impellers 200 are disposed within the first housing 140, and the two second impellers 600 and the return valve 400 between the two second impellers 600 are disposed within the second housing 160. Therefore, the gas discharged from the first impellers 200 can be precisely guided to the second impellers 600 through the volute 150 to further pressurize the gas, reduce the risk of airflow turbulence, and effectively reduce airflow loss.

[0034] Reference Figure 2 As shown, it can be understood that the first drive assembly 300 is connected to and used to drive the two first impellers 200 to rotate. The second drive assembly 700 is connected to and used to drive the two second impellers 600 to rotate.

[0035] Specifically, the structure of the first drive component 300 will be described in detail below, and the structure of the second drive component 700 can be referred to the structure of the first drive component 300.

[0036] Reference Figure 2 As shown, the first drive assembly 300 includes a stator 310, a rotor 320, and a rotating shaft 330. The stator 310 is wound around the outer periphery of the rotor 320, and the rotating shaft 330 is fixedly connected to the rotor 320. The stator 310 and rotor 320 are located inside the first housing 140 and at one end near the volute 150. The rotating shaft 330 is arranged along the central axis of the first housing 140 and is fixedly connected to two first impellers 200. Thus, when the rotor 320 rotates, it drives the two first impellers 200 to rotate, thereby realizing the rotation of the two first impellers 200 through the first drive assembly 300.

[0037] It is understandable that, similarly, the second drive component 700 can drive the two second impellers 600 to rotate.

[0038] Reference Figure 2 and Figure 4 As shown, it can be understood that both the first impeller 200 and the second impeller 600 are configured as centrifugal impellers, meaning that both the first impeller 200 and the second impeller 600 have axial air intake and radial air outlet. Specifically, in either the first impeller 200 or the second impeller 600, each impeller is provided with a second air inlet 230 and multiple second air outlets 240. The second air inlet 230 is located at one axial end of the impeller, and the multiple second air outlets 240 are located on the outer peripheral wall of the impeller and are arranged at equal intervals along the axial direction of the impeller. It is easy to understand that the impeller includes multiple blades 210, which are arranged at equal intervals along the circumference of the impeller. A flow passage 220 is defined between two adjacent blades 210, and the opening of the flow passage 220 away from the rotation axis of the impeller is the second air outlet 240.

[0039] Reference Figure 2 and Figure 5 As shown, the return flow device 400 is configured for radial air intake and axial air exhaust. Specifically, the return flow device 400 includes multiple guide vanes 410, which are arranged at equal intervals along the circumference of the return flow device 400. A guide channel 420 is defined between two adjacent guide vanes 410. The end of the guide channel 420 facing away from the central axis of the return flow device 400 is the air inlet of the return flow device 400. The air outlet of the return flow device 400 is located at one end of the return flow device 400 along the central axis, and the air outlet of the return flow device 400 is located at the end of the return flow device 400 facing the first air outlet 130. The guide channel 420 is used to guide the airflow between two adjacent first impellers 200 (or two adjacent second impellers 600).

[0040] Reference Figure 2 and Figure 3As shown, it can be understood that the cavity wall of the cavity 120 is spaced apart from the outer peripheral walls of the first impeller 200 (or the second impeller 600) and the outer peripheral wall of the return valve 400. Therefore, when the first drive assembly 300 drives the two first impellers 200 to rotate and the second drive assembly 700 drives the two second impellers 600 to rotate, the gas outside the housing 100 enters the cavity 120 from the first air inlet 110, and flows sequentially through the two first impellers 200 and the return valve 400 between the two first impellers 200, the volute 150, and the two second impellers 600 and the return valve 400 between the two second impellers 600, and is discharged from the first air outlet 130. When the gas flows through the first impeller 200 (or the second impeller 600), the gas enters from the second air inlet 230, flows through the flow channel 220 and is discharged from the second air outlet 240. The gas is compressed by using the high-speed rotating first impeller 200 (or second impeller 600) to increase the gas pressure.

[0041] Reference Figure 2 As shown, it can be understood that gas discharged radially from one impeller flows axially to another impeller through the guide channel 420 of the return flow 400. The guide channel 420 precisely guides the airflow between two adjacent first impellers 200 (or two second impellers 600), which can reduce the risk of airflow turbulence and effectively reduce airflow loss.

[0042] Reference Figure 2 As shown, it can be understood that the two first impellers 200 and the two second impellers 600 sequentially compress the gas, thereby progressively increasing the gas pressure and thus increasing the pressure difference between the first outlet 130 and the first inlet 110, enabling the fan to achieve higher suction power. Compared to a single impeller design, using at least two impellers, while achieving the same suction power, can reduce the impeller speed, thus helping to reduce noise. Simultaneously, the lower impeller speed reduces mechanical losses.

[0043] Reference Figure 2 As shown, it can be understood that the rotational speed of the second impeller 600 is greater than that of the first impeller 200. Therefore, during the operation of the fan, the gas flows through the cavity 120 and is compressed sequentially by the two first impellers 200 and the two second impellers 600, and the gas pressure gradually increases. As the gas pressure increases, the second impeller 600, with its higher rotational speed, can quickly further compress the high-pressure gas, reducing the risk of airflow turbulence caused by the diffusion of high-pressure gas, i.e., reducing turbulence, reducing airflow loss, improving the operating efficiency of the fan, which is beneficial for improving the suction power of the fan and enhancing the cleaning effect of the cleaning equipment.

[0044] In other embodiments, it is understood that the number of first impellers 200 is not limited to two, but can also be one, three, or more. If the number of first impellers 200 is one, then no return valve 400 is provided inside the first housing 140. If the number of first impellers 200 is three or more, then a return valve 400 is provided between every two adjacent first impellers 200. Within the output capacity range of the first drive unit, as the number of first impellers 200 increases, the gas pressure can be further increased, thereby further improving the suction power of the fan.

[0045] Similarly, in other embodiments, it is understood that the number of second impellers 600 is not limited to two, but can also be one, three or more, which can be referred to the specific layout of the first impeller 200, and will not be repeated here.

[0046] Reference Figure 2 and Figure 6 As shown, the fan also includes at least two diffusers 500. One diffuser 500 is installed within the first housing 140 and is located on the side of the first impeller 200 facing the volute 150. The other diffuser 500 is installed within the second housing 160 and is located on the side of the second impeller 600 facing the second outlet 240. The diffusers 500 are configured for axial air intake and axial air exhaust. The diffusers 500 are provided with a plurality of diffusion channels 510, which are located on the outer periphery of the diffusers 500 and are arranged at equal intervals along the circumference of the diffusers 500. Inside the first housing 140, the diffuser 500 is defined by the opening of its diffuser channel 510 towards the first impeller 200, and the diffuser 500 itself is defined by the opening of its diffuser channel 510 towards the volute 150. Inside the second housing 160, the diffuser 500 is defined by the opening of its diffuser channel 510 towards the second impeller 600, and the diffuser 500 itself is defined by the opening of its diffuser channel 510 towards the first outlet 130.

[0047] Understandably, the diffuser channel 510 is used to guide and diffuse the gas discharged radially from the first impeller 200 or the second impeller 600. Specifically, the cross-sectional area of ​​the diffuser channel 510 increases from the first air inlet 110 to the first air outlet 130. When the high-pressure gas passes through the diffuser channel 510, it slows down the airflow. This slowing effect converts the kinetic energy of the gas into pressure energy, thereby further increasing the gas pressure and further increasing the pressure difference between the first air outlet 130 and the first air inlet 110, enabling the fan to obtain higher suction.

[0048] In other embodiments, it is understood that the number of diffusers 500 within the first housing 140 or the second housing 160 is not limited to one, but may be two or more, with multiple diffusers 500 arranged sequentially to further increase the gas pressure.

[0049] Reference Figure 2 As shown, it can be understood that the number of blades in the two first impellers 200 and the two second impellers 600 increases sequentially from the first air inlet 110 through the cavity 120 to the first air outlet 130. It is easy to understand that, assuming the outer diameter and axial height of the impeller remain constant, the more blades there are, the smaller the space of a single flow passage 220 of the impeller. Therefore, the size of the flow passage 220 of the two first impellers 200 and the two second impellers 600 decreases sequentially from the first air inlet 110 through the cavity 120 to the first air outlet 130.

[0050] Therefore, during the operation of the fan, as the gas pressure increases, the space of the flow channel 220 through which the gas flows decreases, thereby reducing the risk of airflow turbulence caused by the diffusion of high-pressure gas due to excessive space. This effectively reduces turbulence, thereby reducing airflow loss, effectively improving the operating efficiency of the fan, and also helps to improve the suction of the fan, thus achieving the goal of improving the cleaning effect of the cleaning equipment.

[0051] In other embodiments, it is understood that, similarly, when the number of return valves 400 is at least two, the number of guide vanes 410 of the at least two return valves 400 increases from the first air inlet 110 through the cavity 120 to the first air outlet 130, which can also reduce turbulence, reduce airflow loss, and effectively improve the operating efficiency and suction of the fan, which will not be elaborated here.

[0052] Reference Figure 4 As shown, it can be understood that in the first impeller 200 and the second impeller 600, the number of blades of any one impeller is defined as N, and the number of blades N satisfies: 7 ≤ N ≤ 13. For example, the number of blades of the impeller can be 7, 8, 10, 12, or 13, etc., but it is necessary to ensure that the number of blades of multiple impellers increases from the first air inlet 110 through the cavity 120 to the first air outlet 130. It is easy to understand that if the number of blades of the impeller is too small, the impeller's gas compression capacity is poor, and the pressurization capacity is poor, which will lead to a decrease in the suction power of the fan; if the number of blades of the impeller is too large, the space of the impeller's flow channel 220 is small, the airflow resistance is large, and the airflow loss is large, which will also affect the suction power of the fan. Therefore, by reasonably setting the number of blades of the impeller, the suction power of the fan can be effectively improved.

[0053] Understandably, for a fan including the return valve 400, when gas flows through the impeller's flow passage 220, noise is generated due to friction between the gas and the multiple blades 210 of the impeller. Similarly, when gas flows through the return valve 400's guide passage 420, noise is generated due to friction between the gas and the multiple guide vanes 410 of the return valve 400. When these two types of noise are at the same frequency, resonance will occur, resulting in even louder noise.

[0054] Therefore, it is understandable that the number of guide vanes 410 of any return valve 400 is coprime to the number of blades of any impeller. This allows the frequencies of the noise generated by the friction between the return valve 400 and the impeller and the gas to be staggered, avoiding greater noise due to resonance, thereby effectively reducing the operating noise of the fan.

[0055] Reference Figure 2 and Figure 3 As shown, it can be understood that the cavity wall of the cavity 120 is spaced apart from the outer peripheral wall of the impeller (first impeller 200 or second impeller 600) and the outer peripheral wall of the reflux 400. Specifically, taking the first outer casing 140 as an example, the cavity wall of the cavity 120 includes a first inner wall 121 and a second inner wall 122. The first inner wall 121 is located radially outside the impeller and is arranged around the outer periphery of the impeller, and is spaced apart from the outer peripheral wall of the impeller radially. The second inner wall 122 is located radially outside the reflux 400 (the reflux 400 located on the side of the impeller facing the volute 150) and is arranged around the outer periphery of the reflux 400, and is spaced apart from the outer peripheral wall of the reflux 400. The two ends of the second inner wall 122 and the first inner wall 121, which are arranged opposite to each other in the direction of the central axis of the first outer casing 140, are connected. It is easy to understand that, in a cross-section perpendicular to the central axis of the first outer casing 140, both the first inner wall 121 and the second inner wall 122 have circular cross-sections. Furthermore, from the first air inlet 110 through the cavity 120 towards the first air outlet 130, the inner diameter of the space surrounded by the first inner wall 121 increases, while the inner diameter of the space surrounded by the second inner wall 122 decreases. Specifically, in a cross-section passing through the central axis of the first outer casing 140, both the cross-sections of the first inner wall 121 and the second inner wall 122 are arc-shaped. Therefore, the gas discharged from the impeller can be guided to the return flow device 400 through the first inner wall 121 and the second inner wall 122, reducing airflow resistance and lowering airflow loss. The second outer casing 160 can be referenced to the first outer casing 140, and will not be described further here.

[0056] Reference Figure 2As shown, it can be understood that the maximum inner diameter of the space surrounded by the first inner wall 121 is defined as D1, which is the diameter of the largest circle intercepted by a section perpendicular to the central axis of the first outer shell 140 on the first inner wall 121. It is easy to understand that if the section of the first inner wall 121 perpendicular to the central axis of the first outer shell 140 is not circular, then D1 is the diameter of the largest circumscribed circle intercepted.

[0057] Reference Figure 2 As shown, it is understandable that, generally speaking, the maximum outer diameters of the first impeller 200 and the second impeller 600 are equal. The maximum outer diameter of any impeller is defined as D2. Generally, if the impeller's outer profile is circular, then D2 is the outer diameter at any point on the impeller. It is easy to understand that if the impeller's outer profile is not circular, then D2 is the diameter of the circumcircle of the impeller's outer profile.

[0058] Reference Figure 2 As shown, it can be understood that the maximum inner diameter D1 of the space surrounded by the first inner wall 121 and the maximum outer diameter D2 of the impeller satisfy: 1.25 ≤ D1 / D2 ≤ 1.43. The ratio between the maximum inner diameter D1 of the space surrounded by the first inner wall 121 and the maximum outer diameter D2 of the impeller can reflect the relative size of the space between the first inner wall 121 and the outer peripheral wall of the impeller relative to the space surrounded by the first inner wall 121. If D1 / D2 < 1.25, the difference between the maximum inner diameter D1 of the space surrounded by the first inner wall 121 and the maximum outer diameter D2 of the impeller is small. The space between the first inner wall 121 and the outer peripheral wall of the impeller is too small, resulting in high airflow resistance and significant airflow loss when gas flows through this space. If D1 / D2 > 1.43, the difference between the maximum inner diameter D1 of the space surrounded by the first inner wall 121 and the maximum outer diameter D2 of the impeller is large. The space between the first inner wall 121 and the outer peripheral wall of the impeller is too large, causing diffusion when high-pressure gas flows through this space, resulting in airflow turbulence and also significant airflow loss. Therefore, ensuring that 1.25 ≤ D1 / D2 ≤ 1.43, for example, values ​​of D1 / D2 such as 1.25, 1.32, 1.38, or 1.43, can effectively reduce airflow loss and improve the operating efficiency and suction power of the fan.

[0059] Reference Figure 2 As shown, it can be understood that the maximum outer diameter of the reflux 400 is defined as D3. Generally speaking, the outer contour of the reflux 400 is circular, then D3 is the outer diameter at any point of the reflux 400. It is easy to understand that if the outer contour of the reflux 400 is not circular, then D3 is the diameter of the circumcircle of the outer contour of the reflux 400.

[0060] Reference Figure 2As shown, it can be understood that the maximum outer diameter D3 of the return valve 400 and the maximum outer diameter D2 of the impeller satisfy the condition: 1.05 ≤ D3 / D2 ≤ 1.2. Typically, the impeller is located on the side of the return valve 400 closest to the first air inlet 110. Taking the first housing 140 as an example, given that the inner diameter of the first housing 140 and the maximum outer diameter of the impeller are determined, the ratio of the maximum outer diameter D3 of the return valve 400 to the maximum outer diameter D2 of the impeller reflects the size of the maximum outer diameter of the return valve 400. If D3 / D2 < 1.05, the maximum outer diameter of the return valve 400 is too small, resulting in a reduced air inlet area and high airflow resistance; if D3 / D2 > 1.2, the maximum outer diameter of the return valve 400 is too large, reducing the space between the second inner wall 122 and the outer peripheral wall of the return valve 400, which also leads to high airflow resistance. Therefore, ensuring that 1.05 ≤ D3 / D2 ≤ 1.2, for example, that the value of D3 / D2 is 1.05, 1.09, 1.15 or 1.2, can effectively reduce airflow loss and improve the operating efficiency and suction of the fan.

[0061] Reference Figure 2 As shown, it can be understood that for embodiments where the number of first impellers 200 is at least two, the minimum axial spacing between any two adjacent first impellers 200 is defined as L1. Generally, the minimum axial spacing between any two adjacent first impellers 200 is equal, and L1 can be understood as the minimum distance between two walls of adjacent first impellers 200 arranged opposite each other along the axial direction. Since a return valve 400 is installed between two adjacent first impellers 200, the minimum axial spacing L1 between two adjacent first impellers 200 can reflect the size of the space used to install the return valve 400, and further reflects the corner size of the second inner wall 122 of the arc-shaped structure.

[0062] Reference Figure 2As shown, it can be understood that the maximum outer diameter of the first impeller 200 is defined as D6, where D6 = D2. The minimum axial distance L1 between any two adjacent first impellers 200 and the maximum outer diameter D6 of the first impeller 200 satisfies: 1.27 ≤ D6 / L1 ≤ 1.87. Given that the maximum outer diameter D6 of the first impeller 200 is determined, if D6 / L1 < 1.27, the minimum axial distance between two adjacent first impellers 200 is too large, resulting in an excessively large axial dimension of the fan, increasing its volume and hindering installation. If D6 / L1 > 1.87, while the space between two adjacent first impellers 200 meets the requirements for installing the return valve 400, the minimum axial distance between two adjacent first impellers 200 is too small. This results in a large corner of the arc-shaped second inner wall 122, leading to high airflow resistance and significant airflow loss when the gas flows through the space between the second inner wall 122 and the outer peripheral wall of the return valve 400. Therefore, ensuring that 1.27≤D6 / L1≤1.87, for example, D6 / L1 values ​​of 1.27, 1.38, 1.59, or 1.87, can effectively reduce airflow loss, improve the operating efficiency and suction of the fan, optimize the axial dimensions of the fan, reduce its volume, and facilitate installation.

[0063] Similarly, for embodiments where there are at least two second impellers 600, the minimum axial spacing between any two adjacent second impellers 600 is defined as L2, and the maximum outer diameter of the second impeller 600 is defined as D7, where D7 = D2. The maximum outer diameter of the second impeller 600 D7 and the minimum axial spacing L2 between any two adjacent second impellers 600 satisfy: 1.27 ≤ D7 / L2 ≤ 1.87. For example, values ​​of D7 / L2 such as 1.27, 1.38, 1.59, or 1.87 can effectively reduce airflow loss, improve the operating efficiency and suction of the fan, optimize the axial dimensions of the fan, reduce its volume, and facilitate installation. Further details are omitted here.

[0064] Reference Figure 2 As shown, it can be understood that in the first impeller 200 and the second impeller 600, the impeller closer to the first air inlet 110 among any two adjacent impellers is defined as the upper-stage impeller, and the impeller closer to the first air outlet 130 is defined as the lower-stage impeller. The minimum inner diameter of the second air inlet 230 of the upper-stage impeller is defined as D4, and the minimum inner diameter of the second air inlet 230 of the lower-stage impeller is defined as D5. Generally, the outline of the second air inlet 230 in the cross-section perpendicular to the impeller axis is circular, and the inner diameter at any point of the second air inlet 230 is the minimum inner diameter. It is easy to understand that if the outline of the second air inlet 230 in the cross-section perpendicular to the impeller axis is not circular, the minimum inner diameter of the second air inlet 230 is the diameter of the minimum inscribed circle of the second air inlet 230.

[0065] Reference Figure 2As shown, it can be understood that the minimum inner diameter D4 of the second air inlet 230 of the upper stage impeller and the minimum inner diameter D5 of the second air inlet 230 of the lower stage impeller satisfy: 0.8 ≤ D5 / D4 < 1. That is, the minimum inner diameter of the second air inlets 230 of multiple impellers decreases from the first air inlet 110 along the cavity 120 towards the first air outlet 130. Therefore, as the gas pressure gradually increases, the minimum inner diameter of the second air inlet 230 through which the gas flows decreases, thereby reducing the risk of airflow turbulence caused by the diffusion of high-pressure gas due to excessive space, effectively reducing turbulence, and thus reducing airflow loss, effectively improving the operating efficiency and suction of the fan. At the same time, ensuring D5 / D4 ≥ 0.8 avoids the disadvantage of excessively small minimum inner diameter of the second air inlet 230 of the impeller closest to the first air inlet 110, which would lead to high airflow resistance, thereby reducing airflow loss. Therefore, making 0.8≤D5 / D4<1, for example, D5 / D4 values ​​of 0.8, 0.86, 0.9 or 0.98, can effectively reduce airflow loss and improve the operating efficiency and suction of the fan.

[0066] Reference Figure 2 As shown, it can be understood that the minimum axial width of the second outlet 240 of the upper-stage impeller is defined as W1, and the minimum axial width of the second outlet 240 of the next stage is defined as W2, satisfying 0.6≤W2 / W1≤0.9. Generally, the axial width of the second outlet 240 is equal everywhere, and the axial width at any point of the second outlet 240 is the minimum width. It is easy to understand that if the axial width of the second outlet 240 is not equal everywhere, the minimum axial width is used. Similarly, that is, the minimum width of the second outlet 240 of multiple impellers decreases from the first inlet 110 along the cavity 120 towards the first outlet 130. Therefore, as the gas pressure gradually increases, the minimum axial width of the second outlet 240 through which the gas flows decreases, thereby reducing the risk of airflow turbulence caused by the diffusion of high-pressure gas due to excessive space, effectively reducing turbulence, thus reducing airflow loss, and effectively improving the operating efficiency and suction of the fan. Meanwhile, ensuring W2 / W1 ≥ 0.6 avoids the drawback of excessively small axial minimum width of the second outlet 240 of the impeller closest to the first air inlet 110, which would lead to high airflow resistance and thus reduce airflow loss. Therefore, ensuring 0.6 ≤ W2 / W1 ≤ 0.9, for example, with W2 / W1 values ​​of 0.6, 0.75, 0.81, or 0.9, can effectively reduce airflow loss and improve the fan's operating efficiency and suction power.

[0067] The cleaning device of the second aspect of this utility model includes the fan of the first aspect of this utility model. The cleaning device can be a sweeping robot, a vacuum cleaner, etc. The cleaning device uses the suction generated by the fan to pick up dust, hair and other foreign objects to achieve the purpose of cleaning. Since the cleaning equipment adopts all the technical solutions of the fan in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0068] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A fan characterised in that, include: The housing is provided with a first air inlet, a cavity and a first air outlet connected in sequence; At least two impellers are rotatably mounted in the cavity, and the at least two impellers are arranged sequentially from the first air inlet to the first air outlet. The at least two impellers include a first impeller and a second impeller. A first drive component is connected to the first impeller and is used to drive the first impeller to rotate. The second drive assembly is connected to the second impeller and is used to drive the second impeller to rotate. In this configuration, any one of the second impellers is closer to the first air outlet than any one of the first impellers, and the rotational speed of the second impeller is greater than that of the first impeller.

2. The fan of claim 1, wherein: The housing includes a first outer shell, a volute, and a second outer shell. The volute connects the first outer shell and the second outer shell. The first outer shell has a first air inlet at one end away from the volute, and the second outer shell has a first air outlet at one end away from the volute. The first impeller is located inside the first outer shell, and the second impeller is located inside the second outer shell. The volute is used to guide gas from the first outer shell to the second outer shell.

3. The fan of claim 1, wherein: The number of blades of at least two of the impellers increases from the first air inlet to the first air outlet.

4. The fan of claim 3, wherein: The number of blades in any one of the impellers is N, which satisfies: 7≤N≤13.

5. The fan of claim 1, wherein: The number of first impellers is at least two, and the at least two first impellers are arranged sequentially from the first air inlet to the first air outlet. The fan also includes at least one return valve installed in the cavity. A return valve is provided between two adjacent first impellers. The return valve is used to guide the airflow between two adjacent first impellers. And / or, The number of the second impellers is at least two, and the at least two second impellers are arranged sequentially from the first air inlet to the first air outlet. The fan also includes at least one return valve installed in the cavity. One return valve is provided between two adjacent second impellers. The return valve is used to guide the airflow between two adjacent second impellers.

6. The fan of claim 5, wherein: The reflux device includes multiple guide vanes, which are arranged at intervals along the central axis of the reflux device. A guide channel is defined between two adjacent guide vanes, and the guide channel is used to guide gas through. The number of guide vanes in any reflux device is coprime to the number of blades in any impeller.

7. The fan of claim 5 or 6, wherein: The maximum outer diameter of the impeller is D2, and the maximum outer diameter of the reflux device is D3, satisfying: 1.05≤D3 / D2≤1.

2.

8. The fan according to claim 5, characterized in that: When the number of the first impellers is at least two, the minimum axial spacing between any two adjacent first impellers is L1; the maximum outer diameter of the first impeller is D6, satisfying: 1.27≤D6 / L1≤1.87; When the number of the second impellers is at least two, the minimum axial spacing between any two adjacent second impellers is L2; ​​the maximum outer diameter of the second impeller is D7, satisfying: 1.27≤D7 / L2≤1.

87.

9. The fan of claim 1, wherein: The housing includes a first inner wall located radially outside the impeller and arranged around the outer periphery of the impeller. The maximum inner diameter of the space surrounded by the first inner wall is D1, and the maximum outer diameter of the impeller is D2, satisfying: 1.25≤D1 / D2≤1.

43.

10. The fan of claim 1, wherein: The impeller is provided with a second air inlet and multiple second air outlets. The second air inlet is located at one axial end of the impeller, and the multiple second air outlets are located on the outer peripheral wall of the impeller and arranged at intervals along the circumference of the impeller. In any two adjacent impellers, the impeller closer to the first air inlet is the upper stage impeller, and the impeller closer to the first air outlet is the lower stage impeller. The minimum inner diameter of the second air inlet of the upper stage impeller is D4, and the minimum inner diameter of the second air inlet of the lower stage impeller is D5, satisfying: 0.8≤D5 / D4<1.

11. The fan according to claim 10, characterized in that: The width of the second air outlet of the upper stage impeller along the axial direction is W1, and the width of the second air outlet of the lower stage impeller along the axial direction is W2, satisfying: 0.6≤W2 / W1≤0.

9.

12. Cleaning apparatus, characterized in that Includes the wind turbine as described in any one of claims 1 to 11.

Images