CN114776614A

CN114776614A - Fan and cleaning equipment

Info

Publication number: CN114776614A
Application number: CN202210622079.6A
Authority: CN
Inventors: 蒋婷婷; 吕琢; 方佳旗; 马寅辉; 郑礼成; 吴迪
Original assignee: Guangdong Welling Motor Manufacturing Co Ltd
Current assignee: Guangdong Welling Motor Manufacturing Co Ltd
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2022-07-22

Abstract

The invention discloses a fan and a cleaning device with the fan, wherein the fan comprises: the motor comprises a shell, a stator assembly and a rotor assembly, wherein the stator assembly is arranged in the shell, 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; the diffuser comprises a first diffuser structure and a shell, wherein the first diffuser structure is arranged between the impeller and the casing, the shell comprises a diffuser part and an air guide part, the axial direction of the rotating shaft is followed, the end face of the impeller is far away from the shell, the distance L2 between the end face of the impeller and the end face of the first diffuser structure is far away from is larger than or equal to 1mm, and the distance L1 is smaller than or equal to three times that of the first diffuser structure. The fan and the diffuser meet a certain parameter relationship, and the air flow separation loss at the outlet of the diffuser can be reduced to a certain extent, so that the fluid noise in the fan is improved.

Description

Fan and cleaning equipment

Technical Field

The invention relates to the technical field of household appliances, in particular to a fan and cleaning equipment.

Background

In the related art, the fan used in the handheld cleaning equipment has the characteristics of small volume, high rotating speed and the like. The working process of the fan is as follows: the impeller is driven by the motor to rotate, the rotating impeller brings air into the fan from the inlet of the fan cover, and the air obtains larger kinetic energy under the action of the impeller, flows into the diffuser from the edge of the impeller along the radial direction of the impeller to be diffused and then flows out of the casing.

When airflow flows out of the impeller and enters the diffuser, the fluid impacts structures such as the diffuser and the casing, so that the kinetic energy loss of the fluid is large, and the separation loss of the fluid is easy to generate at the tail end of the outlet of the diffuser, so that the connection between the impeller and the diffuser, namely an interference area, and fluid noise is generated inside the diffuser.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a fan, which is provided with an air duct, wherein the air duct and a diffuser have a certain parameter relation, and the air duct can reduce the air flow separation loss at the outlet of the diffuser to a certain extent, so that the fluid noise in the fan is improved.

The invention also provides cleaning equipment with the fan.

According to the embodiment of the first aspect of the invention, the fan comprises:

the driving device comprises a shell, a stator assembly and a rotor assembly, wherein the stator assembly is arranged in the shell, the rotor assembly is rotationally connected with the stator assembly, the rotor assembly is provided with a rotating shaft, an impeller is fixedly arranged on the rotating shaft, and an impeller cover is provided with a fan cover;

the diffuser comprises a first diffusion structure and a shell, the first diffusion structure is arranged between the impeller and the casing, the shell comprises a diffusion part and a wind guide part, the diffusion part is arranged on the outer side of the first diffusion structure and forms a diffusion channel with the first diffusion structure, one end, far away from the impeller, of the shell is the wind guide part, the wind guide part surrounds the casing to form a wind channel, and along the axial direction of the rotating shaft, the distance L2 between the end face, far away from the impeller, of the shell and the end face, far away from the impeller, of the first diffusion structure is larger than or equal to 1mm, and the length L1 of the first diffusion structure is smaller than or equal to three times.

The fan provided by the embodiment of the invention at least has the following beneficial effects: the fan is provided with the diffuser, and wherein the diffuser is provided with first diffusion structure and shell, and the shell includes diffusion portion and wind-guiding portion, and diffusion portion sets up in the outside of first diffusion structure, and wind-guiding portion then forms the wind channel around the casing, has certain parameter relation between the wind channel of fan and the diffuser, can reduce the air flow separation loss at the diffuser exit to a certain extent to improve the inside fluid noise of fan.

According to some embodiments of the invention, the casing is provided with a fin, at least part of the fin is located in the air duct, and a distance L3 from one end of the fin far away from the impeller to one end of the first diffuser structure far away from the impeller is greater than L2 in the axial direction of the rotating shaft.

According to some embodiments of the invention, the diffuser is further provided with a second diffuser structure, the second diffuser structure is arranged in the air duct, and the length L4 of the second diffuser structure is smaller than L2 along the axial direction of the rotating shaft.

According to some embodiments of the invention, a distance L5 between an end face of the second diffuser structure far away from the impeller and an end face of the air outlet of the air duct along the axial direction of the rotating shaft is greater than or equal to 1 mm.

According to some embodiments of the invention, a protrusion is provided in the casing, the protrusion being provided with a positioning support surface for supporting the stator.

According to some embodiments of the invention, the locating support surface is an interference fit with an outer wall of the stator.

According to some embodiments of the present invention, in the axial direction of the rotating shaft, the distance from the end of the positioning support surface close to the impeller to the end of the primary diffuser structure far away from the impeller is m1, the casing is provided with a fin, at least part of the structure of the fin is located in the air duct, and the distance n1 from the end of the fin close to the impeller to the end of the primary diffuser structure far away from the impeller is less than or equal to m 1.

According to some embodiments of the invention, in the axial direction of the rotating shaft, the distance from one end of the positioning support surface far away from the impeller to one end of the primary diffuser structure far away from the impeller is m2, and the distance L3 from one end of the fin far away from the impeller to one end of the primary diffuser structure far away from the impeller is greater than or equal to m 2.

According to some embodiments of the invention, the first diffuser structure is circumferentially provided with a plurality of stationary vanes, the stationary vanes having a smaller thickness at an end closer to the impeller than at an end farther from the impeller.

According to some embodiments of the invention, the number of the stationary blades is 9 or more and 13 or less.

A cleaning device according to an embodiment of the second aspect of the invention comprises:

a wind turbine as in an embodiment of the first aspect of the invention.

The cleaning device provided by the embodiment of the invention has at least the following beneficial effects: the diffuser of fan is provided with first diffusion structure and shell, and the shell includes diffuser and wind-guiding portion, and first diffusion structure is located to diffuser cover, and wind-guiding portion then forms the wind channel around the casing, has certain parameter relation between diffuser and the wind-guiding portion, can reduce the air separation loss in diffuser exit to a certain extent to improve the inside fluid noise of fan, make cleaning equipment have good air supply effect and less noise.

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.

Drawings

The invention is further described with reference to the following figures and examples, in which:

FIG. 1 is a schematic view of a wind turbine provided in an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the blower of FIG. 1;

FIG. 3 is a schematic diagram of a housing according to an embodiment of the invention;

FIG. 4 is a cross-sectional view of the housing of FIG. 3;

FIG. 5 is a graph of the number of fins as a function of fan efficiency and winding temperature;

FIG. 6 is a noise spectrum graph of a fan;

FIG. 7 is an internal schematic view of the enclosure;

FIG. 8 is a schematic view showing the relationship between the lengths of the positioning support surfaces;

FIG. 9 is a schematic view of a fan configured with a second diffuser structure.

Reference numerals:

the fan comprises a driving device 100, a casing 110, a convex portion 111, a positioning support surface 112, a stator assembly 120, a rotor assembly 130, a rotating shaft 140, fins 150, a head end 151, a tail end 152, a diffuser 200, a casing 210, an air guide portion 211, a diffuser portion 212, a first diffuser structure 220, an air outlet 221, an air duct 230, an impeller 300, an air cover 400, an air cover opening 410, a contact portion 420 and a second diffuser structure 500.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to 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 illustrative only for the purpose of explaining the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If there is a description of first and second for the purpose of distinguishing technical features only, this is not to be understood as indicating or implying a relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.

In the description of the present invention, unless otherwise specifically limited, terms such as set, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention by combining the specific contents of the technical solutions.

At present, the handheld cleaning equipment is widely applied to the life of people and has good market prospect. The fan used by the cleaning equipment has the characteristics of small volume, high rotating speed and the like, and the rotating speed of the fan can reach between 6 ten thousand and 15 ten thousand rpm generally. The working process of the fan is as follows: the impeller is driven by the motor to rotate, the rotating impeller brings air into the fan from the inlet of the fan cover, and the air obtains larger kinetic energy under the action of the impeller, then flows into the diffuser from the edge of the impeller along the radial direction of the impeller to be diffused, and then flows out of the casing. When airflow flows out of the impeller and enters the diffuser, the fluid impacts structures such as the diffuser and the casing, so that the kinetic energy loss of the fluid is large, and the fluid is easy to generate separation loss at the tail end of the outlet of the diffuser, so that the connection between the impeller and the diffuser, namely an interference area, and fluid noise is generated inside the diffuser.

Aiming at the technical problems of the fans, the invention provides the fan, the structure of the fan is provided with an air channel, the air channel and the axial length of a diffuser have a certain parameter relation, and the air flow separation loss at the outlet of the diffuser can be reduced to a certain extent, so that the fluid noise is improved.

The fan provided by the embodiment of the invention is applied to cleaning equipment such as a dust collector, a floor washing machine and the like.

Referring to fig. 1 and 2, fig. 1 is a schematic view of a fan provided in an embodiment of the present invention, and fig. 2 is a cross-sectional view of the fan in fig. 1, where the fan provided in the embodiment of the present invention includes: the drive device 100, the diffuser 200, the impeller 300, and the fan cover 400. The diffuser 200 is disposed on the driving device 100, the impeller 300 is disposed above the diffuser 200 and connected to the driving device 100, that is, the diffuser 200 is disposed between the driving device 100 and the impeller 300, air accelerated by the impeller 300 flows into the diffuser 200, the fan housing 400 is covered on the impeller 300 and connected to the diffuser 200, such that an enclosed space is formed at the impeller 300, the top of the fan housing 400 is provided with a fan housing opening 410, and air flows into the fan housing 400 from the position of the fan housing opening 410, that is, the position of the impeller 300. Wherein, the working process of fan as follows: the driving device 100 drives the impeller 300 to rotate at a high speed, the impeller 300 drives air to rotate so that the air flow obtains kinetic energy inside the fan housing 400, and the air flow enters the diffuser 200 from the bottom of the impeller 300, wherein the position from the bottom of the impeller 300 to the air inlet at the top of the diffuser 200 is an interference area, the interference area easily generates air flow noise, the diffuser 200 needs to be arranged so that the air flow in the interference area can rapidly enter the diffuser 200 for diffusion, so as to reduce the air flow noise, specifically, the pressure energy of the air flow is increased and the air flow rate is accelerated under the action of the diffuser 200, the air flow passing through the diffusion flows out of the diffuser 200, and negative pressure is formed at the opening of the fan housing 400 so that the air continuously flows into the fan, thereby achieving the purpose of air supply.

The driving apparatus 100 includes a casing 110, a stator assembly 120, and a rotor assembly 130, and the rotor assembly 130 is provided with a rotating shaft 140. Casing 110 has the inner chamber, stator module 120 sets up in the inner chamber and is fixed in the inner chamber wall, rotor subassembly 130 and stator module 120 cooperation, specifically, the rotor subassembly rotates to be connected in stator module, rotor subassembly 130 rotates to be connected in stator module 120, pivot 140 sets up on rotor subassembly 130, the top of casing 110 is provided with the through-hole so that pivot 140 passes casing 110, pivot 140 is located casing 110 at the central axis position on the vertical direction, the axial direction of fan promptly represents the direction of pivot 140.

It should be noted that the diffuser 200 includes a first diffuser structure 220 and a housing 210. The first diffusion structure 220 is disposed on the top of the casing 110, i.e., above the casing 110 as shown in fig. 2, the first diffusion 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 diffusion structure 220. The casing 210 of the diffuser 200 is provided with a diffuser portion 212 and an air guide portion 211, and the diffuser portion 212 of the casing 210 is disposed outside the first diffuser structure 220 and forms a diffuser passage with the first diffuser structure 220. The casing 210 is provided with a wind guiding portion 211, a part of the casing 210 protruding out of the diffuser 212 is the wind guiding portion 211, the wind guiding portion 211 surrounds the casing 110 to form a wind channel 230, specifically, the wind guiding portion 211 is a part of one end of the casing 210 away from the impeller 300 protruding downwards out of the first diffuser structure 220, and the wind guiding portion 211 has an effect of guiding airflow to enable the airflow to flow out of the fan and to be stable in a forward direction. Compared with the disadvantages of the traditional fan, the fan provided by the embodiment of the invention is provided with the air channel 230 to stably guide the pressurized air flow, so that the air flow is more stable before flowing out of the fan, wherein the air flow comprises a more stable flow speed and a more stable flow direction, the separation loss at the position of the air flow outlet of the fan is effectively reduced, and the air supply efficiency is improved.

It should be noted that, in the axial direction of the rotating shaft 140, a 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 1mm, and is less than or equal to three times the length L1 of the first diffuser structure 220. Specifically, as shown in fig. 2, L1 is the length of the first diffuser structure 220 in the axial direction of the rotating shaft 140, and it is understood that L1 is also the length of the diffuser portion 212 of the casing 210 of the diffuser 200 in the axial direction of the rotating shaft 140, and L2 is the length of the air guiding portion 211 in the axial direction of the rotating shaft 140. It can be understood that, according to the verification of each platform scheme, the corresponding high-speed fan noise performs better when the L2 is greater than or equal to 1mm and less than or equal to three times the L1 along the axial direction of the rotating shaft 140.

It should be noted that the impeller 300 of the fan is disposed at one end of the rotating shaft 140, and the rotating shaft 140 of the driving device 100 drives the impeller 300 to rotate so as to drive the air to rotate, so that the air flow obtains kinetic energy. Specifically, the impeller 300 is disposed above the first diffuser structure 220, so that the airflow enters the diffuser 200 for diffusion after being accelerated by the impeller 300, that is, the first diffuser structure 220 is disposed between the impeller 300 and the casing 110. Impeller 300 covers and is provided with fan housing 400, and the bottom of fan housing 400 supports the shell 210 of diffuser 200, specifically, fan housing 400 is provided with abutting part 420 and abutting part 420 surrounds shell 210, that is, the inner wall of abutting part 420 supports shell 210, and abutting part 420 and shell 210 interference fit make the contact surface of fan housing 400 and shell 210 closely laminate, prevent that the air current from flowing out between fan housing 400 and shell 210. In other embodiments, the hood 400 is fixedly connected to the housing 210 of the diffuser 200. The fan housing 400 is arranged to form a cavity between the impeller 300 and the fan housing 400, so that the air is accelerated in the cavity to obtain kinetic energy, and an opening of the fan housing 400 is formed in the top of the fan housing 400, and the air flows into the fan from the opening of the fan housing 400.

Referring to fig. 3 and 4, the casing 110 is provided with a plurality of fins 150, and the plurality of fins 150 are circumferentially disposed at the outside of the casing 110. Because the fan can produce a large amount of heats in the course of the work, can influence the work efficiency of fan if the high temperature of fan, so it needs the key consideration when designing the fan structure to accelerate the heat dissipation of fan. The fins 150 function to increase the heat dissipation of the fan casing 110, and the principle is to increase the contact area of the fan casing 110 and the airflow, so that the airflow takes more heat away during the flowing process, and in particular, the fins 150 are arranged along the axial direction of the rotating shaft 140, when the airflow flows to the position of the fins 150 of the casing 110 after being diffused by the diffuser 200, the fins 150 increase the contact area between the airflow and the casing 110, so that the airflow can take more heat away in the flowing process, wherein, because the fins 150 are arranged along the axial direction of the rotating shaft 140, the fins 150 also have a guiding function to the air flow, after the air flow is diffused by the diffuser 200, the direction of movement upon entering the air duct 230 is spirally downward around the housing 110, when the air flow moves down to the position of the fin 150, the air flow collides against the fin 150 to change the moving direction, and the air flow moves down in the vertical direction under the guiding action of the fin 150. In other embodiments, the fins 150 may be designed in an arc shape, that is, the fins 150 are spirally disposed around the casing 110, so that when the design is performed, the air flow moving to the position of the fins 150 will continue to move in a spiral downward direction until flowing out of the fan.

It should be noted that, as shown in fig. 2, in the axial direction of the rotating shaft 140, a 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. Fins 150 have a leading end 151 and a trailing end 152, with leading end 151 at an upper portion and trailing end 152 at a lower portion, it being understood that leading end 151 is the end of fins 150 proximate impeller 300 and trailing end 152 is the end of fins 150 distal from impeller 300. The L3 is larger than the L2, that is, the tail end 152 of the fin 150 needs to be arranged outside the air guide part 211, so that the advantage of the arrangement is that when the airflow flows out of the air guide part 211, the airflow can be guided to flow stably through the fin 150, the separation loss at the position of the airflow outlet is further reduced, and the air supply efficiency of the fan is improved. It can be understood that when L3 is smaller than L2, that is, the fins 150 are completely disposed in the air duct 230, and the tail ends 152 of the fins 150 are located above the bottom of the air guiding portion 211, this arrangement has the disadvantage that the air flow is guided in the air duct 230 by the fins 150, and when flowing out of the air duct 230, because the casing 110 has no other guiding structure, separation loss is still easily formed at the air flow outlet.

It should be noted that the diffuser 200 is further provided with a second diffusion structure, the second diffusion structure may be a second-stage diffusion structure or a second-stage diffusion structure plus a third-stage diffusion structure, and the like, that is, the second diffusion structure may be a second-stage diffusion structure or a multi-stage diffusion structure including a second-stage diffusion structure and a third-stage diffusion structure. When the diffuser 200 is provided with the first diffuser structure 220 and the second diffuser structure, as shown in fig. 9, the second diffuser structure is disposed in the air duct 230 and located at an end of the first diffuser structure 220 away from the impeller 300, and a length L4 of the second diffuser structure is smaller than L2 along the axial direction of the rotating shaft 140. It can be understood that L4 is smaller than L2, which means that the second diffuser structure needs to be disposed inside the air duct 230, and a part of the air guiding portion 211 needs to protrude downward from the secondary diffuser structure, so that the advantage of this arrangement is that after the air flows are diffused by the first diffuser structure 220 and the second diffuser structure, the air flow can also pass through the air duct 230, so that the flow direction of the air flow is more stable.

When the diffuser is provided with the first diffuser structure 220 and the second diffuser structure, the fins 150 may be also provided at the casing 110, and the tail ends 152 of the fins 150 partially protrude from the air guiding portion 211 of the casing 210. When the airflow flows out of the air guide part 211, the airflow can be guided to stably flow through the fins 150, so that the separation loss at the position of the airflow outlet is further reduced, and the air supply efficiency of the fan is improved. It can be understood that the tail end 152 of the fin 150 is disposed below the bottom of the wind guiding portion 211, that is, a part of the fin 150 needs to be disposed outside the wind duct 230, which is favorable for the stable flow direction of the airflow at the outlet of the wind duct 230 and is not easy to generate separation loss.

It should be noted that, along the axial direction of the rotating shaft, a distance L5 from the end surface of the second diffusion structure far away from the impeller to the end surface of the air outlet of the air duct is greater than or equal to 1 mm. When L5 is greater than or equal to 1mm, 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 the relevant experiment, when L5 is more than or equal to 1mm, the air current can not flow to other directions immediately because the fan is provided with wind channel 230 when flowing out from the second diffusion structure, and the air current still can flow certain distance along wind channel 230, just can flow out the fan after the stability and the direction in wind channel 230 to reduce separation loss to a certain extent.

It should be noted that the second diffusion structure is not limited to the two-stage diffusion structure and the three-stage diffusion structure, and the second diffusion structure may also include a multi-stage diffusion structure, and when the second diffusion structure includes the multi-stage diffusion structure, the second diffusion structure is also applicable to the above relational expression, and details are not repeated here. It is understood that the diffuser 200 may be a vaned diffuser or a vaneless diffuser. The vaneless diffuser is generally composed of only two parallel smooth wall surfaces, and has the advantages of simple structure, low manufacturing cost, flat performance curve and wide stable working condition range. But the vaneless diffuser has a longer diameter and larger gas flow loss; the vane diffuser is formed by uniformly distributing a certain number of vanes along the circumference in a parallel and smooth wall surface of the vaneless diffuser, and the direction angle of a gas medium is basically kept unchanged when the gas medium flows in the vaneless diffuser. However, in the vane diffuser, the gas must flow in the vane direction, and therefore, the flow condition is good, the flow loss is small, and the efficiency is high.

Note that, when a vane diffuser is used, that is, when the first diffuser structure 220 uses a vane diffuser, the first diffuser structure 220 is provided with a hub and a plurality of stationary vanes. Specifically, a plurality of stationary blades are circumferentially provided at the hub, wherein the thickness of one end of the stationary blade close to the impeller 300 is smaller than the thickness of one end far from the impeller 300. The end of the stationary blade close to the impeller 300 is a leading edge, the end far away from the impeller 300 is a trailing edge, when the airflow flows in from the leading edge, the pressure of the airflow on the stationary blade is small, and after the airflow flows to the trailing edge, the pressure of the airflow on the stationary blade is increased.

Referring to fig. 5, in the embodiment of the present invention, when the number of the stationary blades is 9 or more and 13 or less, the noise performance of the fan is good, and according to the related test, the 9 to 13 stationary blades are provided to make the pitch between the stationary blades reach the pitch under the good working condition. As can be seen from the graph of fig. 5, when the number of fins 150 is set to be less than 9, the noise is gradually increased as the number of fins 150 is decreased, the noise is small and stable when the number of fins 150 is set to be 9 to 13, and the noise is increased again when the number of fins 150 is greater than 13. And the winding temperature of the fan is also related to the setting number of the fins 150, when the number of the fins 150 is less than 9, the winding temperature is gradually increased along with the reduction of the fins 150, when the number of the fins 150 is 9 to 13, the winding temperature is small and stable, and when the number of the fins 150 is more than 13, the winding temperature can rise.

Referring to fig. 6, a noise spectrum diagram of a fan is shown. The abscissa in the noise spectrum graph represents the frequency and the ordinate represents the amplitude at this frequency. In fig. 6, there are two curves, the thick line, i.e. the bottom curve, is the improved structure of the present application, and the thin line, i.e. the top curve, is the structure before improvement. It can be understood that the thick line is a variation curve of the sound pressure level corresponding to the frequency when L1, which satisfies that L2 is 1mm or more and three times or less, and the thin line is a variation curve of the sound pressure level corresponding to the frequency of the fan before the structural improvement. The sound pressure level is generally used to indicate the intensity of the sound signal, i.e. the pressure pulse. It can be seen from the figure that when the fan operating frequency is between 2KHz and 20KHz, the sound pressure level of the thick line is mostly lower than that of the thinner line, which means that when L2 is equal to or greater than 1mm and L1 is satisfied, the noise generated when the fan operating frequency is between 2KHz and 20KHz is low.

Referring to fig. 7 and 8, the inside of the casing 110 is provided with a protrusion 111, and the protrusion 111 is provided with a positioning support surface 112, and the positioning support surface 112 is used to support the stator 120. Specifically, the locating support surface 112 is an interference fit with the stator 120 of the drive assembly. It can be understood that, drive assembly can produce the heat in the course of the work, in time can improve the air supply efficiency of fan to drive assembly heat dissipation, location holding surface 112 and stator 120 interference fit and location holding surface 112 have certain width along circumference, can increase the area of contact of drive assembly internals and casing 110, thereby accelerate the heat transfer speed of stator 120 and casing 110, because casing 110 is through the forced heat dissipation of forced air cooling mode, take away the heat through the air current on casing 110 surface of flowing through promptly, consequently accelerate the heat transfer speed of stator 120 and casing 110 and can accelerate the inside heat dissipation of drive assembly, the temperature rise reduces more than 10 k.

It should be noted that, along 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 primary diffuser structure 220 away from the impeller 300 is m1, the casing 110 is provided with the fins 150, the fins 150 are at least partially located in the air duct 230, and the distance n1 from the end of the fins 150 close to the impeller 300 to the end of the primary diffuser structure 220 away from the impeller 300 is less than or equal to m 1. The distance from the end of the positioning support surface 112 far away from the impeller 300 to the end of the primary diffuser structure 220 far away from the impeller 300 is m2, and the distance L3 from the end of the fin 150 far away from the impeller 300 to the end of the first diffuser structure 220 far away from the impeller 300 is greater than or equal to m 2. Since the upper half of the casing 110 is narrower and the lower half is wider, when the above relationship is satisfied, the housing 210 of the diffuser 200 does not interfere with the casing 110 after installation, which is beneficial to installation of the fan and reserves a sufficient space for the air duct 230. Meanwhile, the air duct 230 has enough space for installing the fins 150 to satisfy the installation number of the fins 150. This arrangement is beneficial to improving the outlet split of the fan.

The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. The fan, its characterized in that includes:

the driving device comprises a machine shell, a stator assembly and a rotor assembly, wherein the stator assembly is arranged in the machine shell, the rotor assembly is rotationally connected with the stator assembly, the rotor assembly is provided with a rotating shaft, an impeller is fixedly arranged on the rotating shaft, and an impeller cover is provided with a fan cover;

the diffuser comprises a first diffusion structure and a shell, wherein the first diffusion structure is arranged between the impeller and the shell, the shell comprises a diffusion part and an air guide part, the diffusion part is arranged on the outer side of the first diffusion structure and forms a diffusion channel with the first diffusion structure, one end of the impeller, far away from the shell, is the air guide part, the air guide part surrounds the shell to form an air duct, the distance L2 between the end face of the impeller and the end face of the impeller, far away from the shell, along the axial direction of the rotating shaft is larger than or equal to 1mm, and the length L1 of the first diffusion structure is smaller than or equal to three times.

2. The fan of claim 1, wherein the housing is provided with fins, at least part of the fins are located in the air duct, and a distance L3 from an end of the fins far away from the impeller to an end of the first diffuser structure far away from the impeller is greater than L2 in the axial direction of the rotating shaft.

3. The fan as claimed in claim 1, wherein the diffuser further includes a second diffuser structure disposed in the duct, and a length L4 of the second diffuser structure is less than L2 along an axial direction of the rotating shaft.

4. The fan according to claim 3, wherein a distance L5 between an end surface of the second diffuser structure far from the impeller and an end surface of an air outlet of the air duct is greater than or equal to 1mm along an axial direction of the rotating shaft.

5. The fan of claim 1, wherein a protrusion is disposed in the housing, the protrusion providing a locating support surface for supporting the stator.

6. The fan of claim 5 wherein the locating support surface is an interference fit with an outer wall of the stator.

7. The fan set forth in claim 6 wherein the distance from the end of the positioning support surface near the impeller to the end of the primary diffuser structure far from the impeller is m1 in the axial direction of the shaft, the housing is provided with fins, at least part of the fins are located in the air duct, and the distance from the end of the fins near the impeller to the end of the primary diffuser structure far from the impeller is n1 which is less than or equal to m 1.

8. The fan as claimed in claim 7, wherein a distance from an end of the positioning support surface far away from the impeller to an end of the primary diffuser structure far away from the impeller in an axial direction of the rotation shaft is m2, and a distance L3 from the end of the fin far away from the impeller to the end of the primary diffuser structure far away from the impeller is equal to or greater than m 2.

9. The fan as recited in claim 1, wherein the first diffuser structure is circumferentially provided with a plurality of stationary vanes having a smaller thickness at an end proximate the impeller than at an end distal from the impeller.

10. The fan as claimed in claim 9, wherein the number of the stationary blades is 9 or more and 13 or less.

11. Cleaning apparatus, characterised in that it comprises a fan according to any of claims 1 to 10.