Fan and cleaning device

Abstract

The application discloses a fan and a cleaning device with the fan, wherein the fan comprises a casing, a stator assembly and a rotor assembly, the stator assembly is installed in the casing, the rotor assembly is rotationally connected with the stator assembly, the rotor assembly is provided with a rotating shaft, and an impeller is fixedly arranged on the rotating shaft; and the fan further comprises a diffuser, which comprises a first diffuser structure and a shell, the first diffuser structure is arranged between the impeller and the casing, and the shell comprises a diffuser part and a wind guide part; wherein, along the axial direction of the rotating shaft, the distance L2 from the end surface of the shell away from the impeller to the end surface of the first diffuser structure away from the impeller is greater than or equal to 1 mm and less than or equal to three times the length L1 of the first diffuser structure. The fan and the diffuser satisfy certain parameter relations, can reduce the airflow separation loss at the outlet of the diffuser to a certain extent, and thus improve the fluid noise in the fan.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of household appliances, in particular to a fan and a cleaning device. BACKGROUND

[0002] In the related art, the fan used in the handheld cleaning device has the characteristics of small size and high rotating speed. The working process of the fan is as follows: the impeller rotates under the drive of the motor, the rotating impeller brings air into the fan from the inlet of the shroud, the air obtains a large kinetic energy under the action of the impeller, and then flows into the diffuser for pressure expansion from the edge of the impeller, and then flows out through the casing.

[0003] When the airflow flows out of the impeller and enters the diffuser, the fluid impacts the diffuser and the casing and other structures, causing a large loss of kinetic energy of the fluid, and the fluid is prone to separation loss at the tail end of the outlet of the diffuser, thereby causing fluid noise at the connection between the impeller and the diffuser, i.e., the interference zone, and inside the diffuser. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a fan, which has a wind channel in the structure, and the wind channel has a certain parameter relationship with the diffuser, which can reduce the airflow separation loss at the outlet of the diffuser to a certain extent, thereby improving the fluid noise inside the fan.

[0005] The present application also proposes a cleaning device having the above-mentioned fan.

[0006] The fan according to the first aspect of the present application comprises:

[0007] The driving device comprises a casing, a stator assembly and a rotor assembly, the stator assembly is installed in the casing, the rotor assembly is rotationally connected with the stator assembly, the rotor assembly is provided with a rotating shaft, the rotating shaft is fixedly provided with an impeller, and the impeller is covered with a shroud;

[0008] The diffuser comprises a first diffuser structure and a housing, the first diffuser structure is arranged between the impeller and the casing, the housing comprises a diffuser part and a wind guide part, the diffuser part is arranged outside the first diffuser structure and forms a diffuser passage with the first diffuser structure, the end of the housing away from the impeller is the wind guide part, and the wind guide part surrounds the casing to form a wind channel, wherein, along the axial direction of the rotating shaft, the distance L2 from the end face of the housing away from the impeller to the end face of the first diffuser structure away from the impeller is greater than or equal to 1 mm and less than or equal to three times the length L1 of the first diffuser structure.

[0009] According to the fan of the embodiment of the present application, at least the following beneficial effects are achieved: the fan is provided with a diffuser, wherein the diffuser is provided with a first diffusing structure and a shell, the shell comprises a diffusing part and a wind guiding part, the diffusing part is arranged outside the first diffusing structure, the wind guiding part forms an air duct around the shell, and the air duct of the fan and the diffuser have a certain parameter relationship, which can reduce the airflow separation loss at the outlet of the diffuser to a certain extent, thereby improving the fluid noise in the fan.

[0010] According to some embodiments of the present application, the shell is provided with fins, at least part of the structure of the fins is located in the air duct, and the distance L3 between the end of the fins away from the impeller and the end of the first diffusing structure away from the impeller is greater than L2 along the axial direction of the rotating shaft.

[0011] According to some embodiments of the present application, the diffuser is further provided with a second diffusing structure, the second diffusing structure is arranged in the air duct, and the length L4 of the second diffusing structure is less than L2 along the axial direction of the rotating shaft.

[0012] According to some embodiments of the present application, the distance L5 between the end of the second diffusing structure away from the impeller and the end face of the air outlet of the air duct is greater than or equal to 1 mm along the axial direction of the rotating shaft.

[0013] According to some embodiments of the present application, a convex part is arranged in the shell, the convex part is provided with a positioning support surface, and the positioning support surface is used to support the stator.

[0014] According to some embodiments of the present application, the positioning support surface is in interference fit with the outer wall of the stator.

[0015] According to some embodiments of the present application, the distance between the end of the positioning support surface close to the impeller and the end of the first diffusing structure away from the impeller is m1 along the axial direction of the rotating shaft, the shell is provided with fins, at least part of the structure of the fins is located in the air duct, and the distance n1 between the end of the fins close to the impeller and the end of the first diffusing structure away from the impeller is less than or equal to m1.

[0016] According to some embodiments of the present application, the distance between the end of the positioning support surface away from the impeller and the end of the first diffusing structure away from the impeller is m2 along the axial direction of the rotating shaft, and the distance L3 between the end of the fins away from the impeller and the end of the first diffusing structure away from the impeller is greater than or equal to m2.

[0017] According to some embodiments of the present application, the first diffusing structure is circumferentially provided with a plurality of stationary vanes, and the thickness of the end of the stationary vanes close to the impeller is smaller than the thickness of the end of the stationary vanes away from the impeller.

[0018] According to some embodiments of the present invention, the number of stationary blades is greater than or equal to 9 and less than or equal to 13.

[0019] A cleaning device according to a second aspect embodiment of the present invention includes:

[0020] The fan as described in the first aspect embodiment of the present invention.

[0021] The cleaning equipment according to the embodiments of the present invention has at least the following beneficial effects: the diffuser of the fan is provided with a first diffuser structure and a housing, the housing includes a diffuser part and a guide part, the diffuser part is covered by the first diffuser structure, and the guide part forms an air duct around the housing. There is a certain parameter relationship between the diffuser part and the guide part, which can reduce the airflow separation loss at the diffuser outlet to a certain extent, thereby improving the fluid noise inside the fan, so that the cleaning equipment has a good air supply effect and low noise.

[0022] Additional aspects and advantages of the 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

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0024] Figure 1 A schematic diagram of a fan provided in an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A cross-sectional view of the fan in the middle;

[0026] Figure 3 This is a schematic diagram of the casing provided in an embodiment of the present invention;

[0027] Figure 4 for Figure 3 Cross-sectional view of the middle casing;

[0028] Figure 5 The graph shows the relationship between the number of fins, the fan's air delivery efficiency, and the winding temperature.

[0029] Figure 6 This is the noise spectrum diagram of the fan;

[0030] Figure 7 This is a schematic diagram of the internal structure of the casing;

[0031] Figure 8 This is a schematic diagram showing the length relationship of the positioning support surface;

[0032] Figure 9 This is a schematic diagram of a fan equipped with a second diffuser structure.

[0033] Figure label:

[0034] The driving device 100, the casing 110, the convex portion 111, the positioning support surface 112, the stator assembly 120, the rotor assembly 130, the rotating shaft 140, the fin 150, the head end 151, the tail end 152, the diffuser 200, the outer shell 210, the air guide portion 211, the diffuser portion 212, the first diffuser structure 220, the air outlet 221, the air duct 230, the impeller 300, the fan cover 400, the fan cover opening 410, the abutting portion 420, the second diffuser structure 500. DETAILED DESCRIPTION

[0035] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are for the purpose of explaining the present application only, and should not be construed as limiting the present application.

[0036] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application.

[0037] In the description of the present application, the meaning of several is one or more, and the meaning of multiple is more than two. Greater than, less than, more than, etc. are understood as not including the number, and above, below, etc. are understood as including the number. If it is described as first, second, 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 technical features indicated or the order of technical features indicated.

[0038] In the description of the present application, unless otherwise explicitly limited, the words such as setting, mounting, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0039] At present, the handheld cleaning equipment is widely used in people's life and has good market prospect. The fan used in the cleaning equipment has the characteristics of small size and high rotating speed, and the rotating speed can reach 60-150 thousand rpm. The working process of the fan is as follows: the impeller is rotated under the driving of the motor, the rotating impeller brings the air into the fan from the air inlet of the air baffle, the air obtains large kinetic energy under the action of the impeller, and then flows into the diffuser for pressure expansion along the radial direction of the impeller, and then flows out of the casing. When the airflow flows out of the impeller and enters the diffuser, the fluid impacts the diffuser and the casing and other structures, so that the kinetic energy of the fluid is greatly lost, and the fluid separation loss is easy to occur at the tail end of the outlet of the diffuser, so that the fluid noise is generated at the connecting part of the impeller and the diffuser, that is, the interference area and the inside of the diffuser.

[0040] In view of the technical problems of the fan, the fan provided by the application has a structure with an air duct, and the axial length of the air duct and the diffuser has a certain parameter relationship, which can reduce the airflow separation loss at the outlet of the diffuser to a certain extent, thereby improving the fluid noise.

[0041] The fan provided by the embodiment of the application is applied to the cleaning equipment such as the dust collector and the scrubber.

[0042] Referring to Figure 1 and Figure 2 , Figure 1 is a schematic view of the fan provided by the embodiment of the application, Figure 2 is Figure 1The cross-sectional view of the fan in the embodiment of the present application provides a fan, which comprises a driving device 100, a diffuser 200, an impeller 300 and a fan cover 400. The diffuser 200 is arranged on the driving device 100, the impeller 300 is arranged above the diffuser 200 and connected to the driving device 100, i.e. the diffuser 200 is arranged between the driving device 100 and the impeller 300. The air accelerated by the impeller 300 flows into the diffuser 200, the fan cover 400 is arranged on the impeller 300 and connected to the diffuser 200, so that a surrounding space is formed at the impeller 300. The top of the fan cover 400 is provided with a fan cover opening 410, and the air flows into the inside of the fan cover 400 from the position of the fan cover opening 410, i.e. the position of the impeller 300. The working process of the fan is as follows: the driving device 100 drives the impeller 300 to rotate at high speed, the impeller 300 drives the air to rotate, so that the airflow obtains kinetic energy in the inside of the fan cover 400. The airflow enters the diffuser 200 from the bottom of the impeller 300. The position from the bottom of the impeller 300 to the air inlet of the top of the diffuser 200 is an interference zone, which is prone to produce airflow noise. The diffuser 200 is arranged to make the airflow in the interference zone quickly enter the diffuser 200 for expansion, so as to reduce the airflow noise. Specifically, under the action of the diffuser 200, the pressure energy of the airflow increases and the flow rate of the airflow increases. The expanded airflow flows out of the diffuser 200, and the opening of the fan cover 400 forms a negative pressure, so that the air continuously flows into the fan, thereby achieving the purpose of air supply.

[0043] It should be noted that the driving device 100 comprises a shell 110, a stator assembly 120 and a rotor assembly 130. The rotor assembly 130 is provided with a rotating shaft 140. The shell 110 has an inner cavity, the stator assembly 120 is arranged in the inner cavity and fixed to the inner cavity wall, and the rotor assembly 130 cooperates with the stator assembly 120. Specifically, the rotor assembly is rotationally connected to the stator assembly, the rotor assembly 130 is rotationally connected to the stator assembly 120, the rotating shaft 140 is arranged on the rotor assembly 130, the top of the shell 110 is provided with a through hole to enable the rotating shaft 140 to pass through the shell 110, and the rotating shaft 140 is located at the central axis position of the shell 110 in the vertical direction. The axial direction of the fan represents the direction of the rotating shaft 140.

[0044] It should be noted that the diffuser 200 comprises a first diffuser structure 220 and an outer shell 210. The first diffuser structure 220 is arranged on the top of the shell 110, i.e. as shown in the figure, the first diffuser structure 220 is arranged on the top of the shell 110 and the rotating shaft 140 passes through the first diffuser structure 220. The outer shell 210 is arranged on the first diffuser structure 220, and the outer shell 210 is connected to the first diffuser structure 220. Figure 2The first diffuser structure 220 is connected to the casing 110 and can be fixed to the casing 110 by screws, and the rotating shaft 140 of the driving device 100 can pass through the first diffuser structure 220. The casing 210 of the diffuser 200 is provided with a diffuser part 212 and an air guide part 211. The diffuser part 212 of the casing 210 is arranged outside the first diffuser structure 220 and forms a diffuser passage with the first diffuser structure 220. The casing 210 is provided with the air guide part 211, and the part of the casing 210 protruding from the diffuser part 212 is the air guide part 211. The air guide part 211 forms an air duct 230 around the casing 110. Specifically, the air guide part 211 is the part of the casing 210 protruding downward from the first diffuser structure 220 at the end of the casing 210 away from the impeller 300. The air guide part 211 has the function of guiding the flow of air flow to make the air flow stable before flowing out of the fan. The conventional fan does not have the air duct 230. After the air flow is pressurized by the diffuser 200, it is directly discharged from the air outlet 221 of the diffuser 200. The air flow is easy to form separation loss at the air outlet 221, and is easy to form turbulence at the air outlet 221, which reduces the air supply efficiency of the fan. Compared with the conventional fan, the fan provided in the embodiment has the air duct 230 to guide and stabilize the pressurized air flow, so that the air flow becomes more stable before flowing out of the fan, including more stable flow rate and flow direction, which effectively reduces the separation loss at the air outlet position of the fan and improves the air supply efficiency.

[0045] It should be noted that, along the axis of the rotating shaft 140, the distance L2 from the end surface of the casing 210 away from the impeller 300 to the end surface of the first diffuser structure 220 away from the impeller 300 is greater than or equal to 1 mm and less than or equal to three times the length L1 of the first diffuser structure 220. Specifically, as shown in the figure, Figure 2 As shown, L1 is the length of the first diffuser structure 220 along the axis of the rotating shaft 140. It can be understood that L1 is also the length of the diffuser part 212 of the casing 210 of the diffuser 200 along the axis of the rotating shaft 140. L2 is the length of the air guide part 211 along the axis of the rotating shaft 140. It can be understood that, according to the verification of each platform scheme, along the axis of the rotating shaft 140, L2 is greater than or equal to 1 mm and less than or equal to three times L1, and the corresponding high-speed fan noise performs better.

[0046] It should be noted that the impeller 300 of the fan is arranged at one end of the rotating shaft 140, and the rotating shaft 140 of the driving device 100 drives the rotation of the impeller 300 to drive the air to rotate, so that the airflow obtains kinetic energy. Specifically, the impeller 300 is arranged above the first diffuser structure 220, so that the airflow enters the diffuser 200 for diffusing after being accelerated by the impeller 300, that is, the first diffuser structure 220 is arranged between the impeller 300 and the casing 110. The impeller 300 cover is provided with a fan cover 400, and the bottom of the fan cover 400 abuts against the outer shell 210 of the diffuser 200. Specifically, the fan cover 400 is provided with an abutting portion 420, and the abutting portion 420 surrounds the outer shell 210, that is, the inner wall of the abutting portion 420 abuts against the outer shell 210. The abutting portion 420 is in interference fit with the outer shell 210, so that the contact surface of the fan cover 400 and the outer shell 210 is tightly fitted, preventing the airflow from flowing out between the fan cover 400 and the outer shell 210. In other embodiments, the fan cover 400 is fixedly connected with the outer shell 210 of the diffuser 200. The arrangement of the fan cover 400 forms a cavity between the impeller 300 and the fan cover 400, which is conducive to the acceleration of the air in the cavity to obtain kinetic energy. The top of the fan cover 400 is provided with a fan cover 400 opening, and the air flows into the fan from the fan cover 400 opening.

[0047] Referring to Figure 3 and Figure 4 As shown in the drawings, the casing 110 is provided with a plurality of fins 150, and the plurality of fins 150 are circumferentially arranged on the outside of the casing 110. Since a large amount of heat will be generated during the operation of the fan, if the temperature of the fan is too high, it will affect the working efficiency of the fan, so accelerating the heat dissipation of the fan is an important consideration in designing the structure of the fan. The function of the fin 150 is to increase the heat dissipation of the casing 110 of the fan. Its principle is to increase the contact area between the casing 110 of the fan and the airflow, so that the airflow carries away more heat during the flow process. Specifically, the fin 150 is arranged along the axial direction of the rotating shaft 140, and after the airflow is diffused by the diffuser 200, it flows to the position of the fin 150 of the casing 110. The fin 150 increases the contact area between the airflow and the casing 110, so that the airflow can carry away more heat during the flow process. Since the fin 150 is arranged along the axial direction of the rotating shaft 140, the fin 150 also has a guiding effect on the airflow. After the airflow is diffused by the diffuser 200, the movement direction of the airflow when entering the air duct 230 is spirally downward around the casing 110. When the airflow moves downward to the position of the fin 150, the airflow will hit the fin 150 and change direction, and under the guiding action of the fin 150, the airflow moves downward in the vertical direction. In other embodiments, the fin 150 can be designed in an arc shape, that is, the fin 150 is spirally arranged around the casing 110. In this way, when the airflow moves to the position of the fin 150, it will continue to move in the downward spiral direction until it flows out of the fan.

[0048] It should be noted that, asFigure 2 As shown, along the axial direction of the rotation shaft 140, the distance L3 from the end of the fin 150 away from the impeller 300 to the end of the first diffuser structure 220 away from the impeller 300 is greater than L2. The fin 150 has a head end 151 and a tail end 152, the head end 151 is located at the upper part, and the tail end 152 is located at the lower part. It can be understood that the head end 151 is the end of the fin 150 close to the impeller 300, and the tail end 152 is the end of the fin 150 away from the impeller 300. L3 is greater than L2, that is, the tail end 152 of the fin 150 needs to be arranged outside the air guide part 211. The advantage of this arrangement is that when the airflow flows out of the air guide part 211, it can still continue to be guided by the fin 150 to a very stable flow direction, thereby further reducing the separation loss at the airflow outlet position and improving the air supply efficiency of the fan. It can be understood that when L3 is less than L2, that is, the fin 150 is completely arranged inside the air duct 230, and the tail end 152 of the fin 150 is located above the bottom of the air guide part 211. The disadvantage of this arrangement is that the airflow is guided by the fin 150 in the air duct 230, and when it flows out of the air duct 230, the casing 110 does not have other guiding structures, and separation loss is still likely to occur at the airflow outlet.

[0049] It should be noted that the diffuser 200 is also provided with a second diffuser structure. The second diffuser structure can be a two-stage diffuser structure or a two-stage diffuser structure plus a three-stage diffuser structure, etc. That is, the second diffuser structure can be a two-stage diffuser structure or a multi-stage diffuser structure including a two-stage diffuser structure and a three-stage diffuser structure, etc. When the diffuser 200 is provided with the first diffuser structure 220 and the second diffuser structure, as shown in Figure 9 As shown, the second diffuser structure is arranged inside the air duct 230 and located at the end of the first diffuser structure 220 away from the impeller 300. Along the axial direction of the rotation shaft 140, the length L4 of the second diffuser structure is less than L2. It can be understood that L4 is less than L2, that is, the second diffuser structure needs to be arranged inside the air duct 230, and a part of the air guide part 211 needs to protrude downward from the two-stage diffuser structure. The advantage of this arrangement is that after the airflow passes through the expansion of the first diffuser structure 220 and the second diffuser structure, it can still pass through the air duct 230 to make the flow direction of the airflow more stable.

[0050] It should be noted that when the diffuser is provided with the first diffuser structure 220 and the second diffuser structure, the fin 150 can also be arranged at the casing 110, and the tail end 152 of the fin 150 can partially protrude from the air guide portion 211 of the outer shell 210. When the airflow flows out of the air guide portion 211, it can also continue to be guided by the fin 150 to flow stably, thereby further reducing the separation loss at the outlet of the airflow and improving the air supply efficiency of the fan. It can be understood that the tail end 152 of the fin 150 is arranged below the bottom of the air guide portion 211, that is, a part of the fin 150 needs to be arranged outside the air duct 230. This arrangement is beneficial to the stable flow of the airflow at the outlet of the air duct 230 and is not prone to separation loss.

[0051] It should be noted that in the axial direction of the rotating shaft, the distance L5 from the end surface of the second diffuser structure to the outlet end surface of the air duct is greater than or equal to 1 mm. When L5 is greater than or equal to 1 mm, it means that the length of the air duct 230 in the axial direction of the rotating shaft is greater than 1 mm. According to relevant tests, when L5 is greater than or equal to 1 mm, the airflow flowing out of the second diffuser structure will not immediately flow in other directions due to the air duct 230 arranged in the fan, but will flow a certain distance along the air duct 230, and will flow out of the fan after being stabilized and guided by the air duct 230, thereby reducing the separation loss to a certain extent.

[0052] It should be noted that the second diffuser structure is not limited to two-stage and three-stage diffuser structures, and can also include multiple-stage diffuser structures. When multiple-stage diffuser structures are included, the above relationship is also applicable, and will not be described again here. It can be understood that the diffuser 200 can be a blade diffuser or a bladeless diffuser. The bladeless diffuser is usually composed of two parallel smooth walls, which has the advantages of simple structure, low cost, flat performance curve, and wide stable working condition range. However, the bladeless diffuser has a long diameter and large gas flow loss. The blade diffuser is composed of a certain number of blades distributed along the circumference in the parallel smooth walls of the bladeless diffuser. The direction angle of the gas medium remains basically unchanged when flowing in the bladeless diffuser. However, in the blade diffuser, the gas must flow according to the direction of the blades, so the flow condition is better, the flow loss is small, and the efficiency is high.

[0053] It should be noted that when a blade diffuser is used, that is, the first diffuser structure 220 uses a blade diffuser, the first diffuser structure 220 is provided with a hub and a plurality of stationary blades. Specifically, the plurality of stationary blades are circumferentially arranged on the hub, and the thickness of the stationary blade at one end close to the impeller 300 is smaller than the thickness of the stationary blade at the other end away from the impeller 300. The one end of the stationary blade close to the impeller 300 is the head edge, and the other end away from the impeller 300 is the tail edge. When the airflow flows into the head edge, the pressure of the gas on the stationary blade is small, and when the airflow flows to the tail edge, the pressure of the gas on the stationary blade increases.

[0054] Referring to Figure 5 As shown in the figure, in the embodiment of the application, the number of vanes of the static vane is greater than or equal to 9 and less than or equal to 13, and the noise of the fan performs better. According to relevant tests, the number of vanes of the static vane is set to 9 to 13, so that the spacing between the vanes can reach the spacing under the better working condition. Figure 5 As can be seen from the curve, when the number of fins 150 is set to be less than 9, the noise gradually increases with the decrease of the number of fins 150, when the number of fins 150 is set to be 9 to 13, the noise is small and stable, and when the number of fins 150 is greater than 13, the noise will increase again. And the winding temperature of the fan is also related to the number of fins 150, when the number of fins 150 is set to be less than 9, the winding temperature gradually increases with the decrease of the number of fins 150, when the number of fins 150 is set to be 9 to 13, the winding temperature is small and stable, and when the number of fins 150 is greater than 13, the winding temperature will rise again.

[0055] Referring to Figure 6 As shown in the figure, it is the noise spectrum diagram of the fan. The abscissa in the noise spectrum diagram represents the frequency, and the ordinate represents the amplitude at the frequency. Figure 6 There are two curves in the figure, the thick line, that is, the lower curve, is the structure improved in the application, and the thin line, that is, the upper curve, is the structure before improvement. It can be understood that the thick line is the change curve of the sound pressure level corresponding to the frequency when L2 is greater than or equal to 1 mm and less than or equal to three times of L1, and the thin line is the change curve of the sound pressure level corresponding to the frequency of the fan before structure improvement. Generally, sound pressure level is used to represent the strength of sound signal, that is, pressure pulse. As can be seen from the figure, when the working frequency of the fan is between 2KHz and 20KHz, the sound pressure level of the thick line is mostly smaller than that of the thin line, indicating that when L2 is greater than or equal to 1 mm and less than or equal to three times of L1, the noise generated when the working frequency of the fan is between 2KHz and 20KHz is small.

[0056] Referring to Figure 7 and Figure 8As shown, the inside of the casing 110 is provided with a convex part 111, which is provided with a positioning support surface 112 for supporting the stator 120. Specifically, the positioning support surface 112 is in interference fit with the stator 120 of the driving assembly. It can be understood that the driving assembly generates heat during operation, and timely heat dissipation of the driving assembly can improve the air supply efficiency of the fan. The positioning support surface 112 is in interference fit with the stator 120, and the positioning support surface 112 has a certain width in the circumferential direction, which can increase the contact area between the internal parts of the driving assembly and the casing 110, thereby accelerating the heat transfer speed between the stator 120 and the casing 110. Since the casing 110 is forced to dissipate heat by air cooling, i.e., heat is removed by air flow passing through the surface of the casing 110, therefore, accelerating the heat transfer speed between the stator 120 and the casing 110 can accelerate the heat dissipation inside the driving assembly, and the temperature rise is reduced by more than 10k.

[0057] It should be noted that, in the axial direction of the rotating shaft 140, the distance from the end of the positioning support surface 112 close to the impeller 300 to the end of the first diffuser structure 220 away from the impeller 300 is m1, the casing 110 is provided with a fin 150, and the fin 150 is at least partially located in the air duct 230. The distance from the end of the fin 150 close to the impeller 300 to the end of the first diffuser structure 220 away from the impeller 300 is n1, which is less than or equal to m1. The distance from the end of the positioning support surface 112 away from the impeller 300 to the end of the first diffuser structure 220 away from the impeller 300 is m2, and the distance L3 from the end of the fin 150 away from the impeller 300 to the end of the first diffuser structure 220 away from the impeller 300 is greater than or equal to m2. Since the upper half of the casing 110 is narrower and the lower half is wider, when the above relationship is satisfied, the shell 210 of the diffuser 200 will not interfere with the casing 110 after installation, which is conducive to the installation of the fan and reserves sufficient space for the air duct 230. At the same time, the air duct 230 has sufficient space to install the fin 150, which satisfies the installation quantity of the fin 150. Such arrangement is conducive to improving the outlet flow distribution of the fan.

[0058] The embodiments of the application are described in detail above in combination with the drawings, but the application 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 purpose of the application.

Claims

1. A fan, characterized in that, include: A drive unit includes a housing, a stator assembly, and a rotor assembly. The stator assembly is installed inside the housing, and the rotor assembly is rotatably connected to the stator assembly. The rotor assembly is provided with a rotating shaft, and an impeller is fixedly mounted on the rotating shaft. The impeller is covered with a fan shroud. A diffuser includes a first diffuser structure and a housing. The first diffuser structure is disposed between the impeller and the housing. The housing includes a diffuser section and a guide section. The diffuser section is disposed outside the first diffuser structure and forms a diffuser channel with the first diffuser structure. The end of the housing away from the impeller is the guide section. The guide section forms an air duct around the housing. Along the axial direction of the rotating shaft, the distance L2 from the end face of the housing away from the impeller to the end face of the first diffuser structure away from the impeller is greater than or equal to 1 mm and less than or equal to three times the length L1 of the first diffuser structure.

2. The fan according to claim 1, characterized in that, The housing is provided with fins, at least a portion of which is located in the air duct. Along the axial direction of the rotating shaft, the distance L3 from the end of the fin away from the impeller to the end of the first diffuser structure away from the impeller is greater than L2.

3. The fan according to claim 1, characterized in that, The diffuser is further provided with a second diffuser structure, which is disposed in the air duct along the axial direction of the rotating shaft, and the length L4 of the second diffuser structure is less than L2.

4. The fan according to claim 3, characterized in that, Along the axial direction of the rotating shaft, the distance L5 from the end face of the second diffuser structure away from the impeller to the outlet end face of the air duct is greater than or equal to 1 mm.

5. The fan according to claim 1, characterized in that, The housing has a protrusion, and the protrusion has a positioning support surface, which is used to support the stator.

6. The fan according to claim 5, characterized in that, The positioning support surface is interference-fitted with the outer wall of the stator.

7. The fan according to claim 6, characterized in that, Along the axial direction of the rotating shaft, the distance from the end of the positioning support surface near the impeller to the end of the first diffuser structure away from the impeller is m1. The housing is provided with fins, at least a portion of the fins are located in the air duct, and the distance n1 from the end of the fin near the impeller to the end of the first diffuser structure away from the impeller is less than or equal to m1.

8. The fan according to claim 7, characterized in that, Along the axial direction of the rotating shaft, the distance from the end of the positioning support surface away from the impeller to the end of the first diffuser structure away from the impeller is m2, and the distance L3 from the end of the fin away from the impeller to the end of the first diffuser structure away from the impeller is greater than or equal to m2.

9. The fan according to claim 1, characterized in that, The first diffuser structure is provided with a plurality of stationary blades in the circumferential direction, and the thickness of the end of the stationary blades near the impeller is smaller than the thickness of the end away from the impeller.

10. The fan according to claim 9, characterized in that, The number of stationary blades is greater than or equal to 9 and less than or equal to 13.

11. A cleaning device, characterized in that, Including the wind turbine as described in any one of claims 1 to 10.

Images