Diffusion structure, centrifugal fan and household appliance

Abstract

The utility model provides a diffusion structure, centrifugal fan and household electrical appliance equipment, the diffusion structure is used in the household electrical appliance equipment for adsorbing sundries, the diffusion structure comprises a fan shell, and a first-stage flow guide assembly and at least one second-stage flow guide assembly which are arranged in the fan shell in sequence along the flowing direction of airflow, the two-stage flow guide assembly comprises a base and a plurality of static guide vanes arranged on the circumferential surface of the base at intervals. The first-stage static guide vane and at least part of the fan shell are integrally formed, and the first-stage base and the second-stage base are arranged in a split mode. The second-stage static guide vane and the fan shell are arranged in a split mode, or the second-stage static guide vane and part of the fan shell are integrally formed. According to the diffusion structure, the centrifugal fan and the household appliance, the gap between the first-stage static guide vane and the fan shell is eliminated, the flow guide effect is improved, the airflow flowing characteristic of the outer edge of the first-stage static guide vane is improved, the overall efficiency of the centrifugal fan is improved, and the noise of the fan is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of household appliances, in particular to a pressure diffuser structure, a centrifugal fan and household appliances. Background Art

[0002] High-speed centrifugal fans are currently primarily used in cleaning appliances such as robot vacuums, vacuum cleaners, and floor scrubbers. Centrifugal fans use their high-speed rotation to create a high vacuum within the appliance's piping, thereby drawing in dirt and effectively cleaning the floor.

[0003] The structure of a centrifugal fan typically includes a hood, a fan housing, and a motor. The hood has a circular inlet at its entrance, housing a multi-blade centrifugal fan. This multi-blade centrifugal fan includes an impeller composed of multiple blades. The fan housing is connected to the hood and contains a multi-stage flow guide assembly. Each stage of the flow guide assembly includes a base and stationary guide vanes arranged around the base. The cavity between the multi-stage flow guide assembly and the fan housing forms a diffuser duct. The fan housing has an annular outlet below the diffuser duct. The multiple flow guide assemblies are mounted on the motor, and the motor's bearings pass through the multi-stage flow guide assembly to connect to the impeller. During operation, air enters through the circular inlet and initially flows axially, being drawn into the centrifugal fan. The high-speed rotating blades generate a rotating airflow, which then flows out radially. Guided by the hood, the airflow then enters the axial diffuser duct, ultimately flowing out axially under the action of the stationary guide vanes. The static guide vanes within the diffuser duct guide the airflow, converting its dynamic pressure into static pressure, reducing its velocity and ultimately discharging it through the annular outlet. Within the diffuser duct, the static guide vanes at each stage perform the dual functions of expanding pressure and reducing velocity. The shape, number, and number of static guide vanes have a decisive influence on the fan's efficiency and operating characteristics. The guide vanes at each stage, along with the fan casing, form the diffuser structure of the centrifugal fan.

[0004] This type of centrifugal fan has a different number of stationary guide vane stages depending on the actual operating point. For example, some fans have only one stage of guide vanes, some have two, and some even have three or more. Furthermore, air flows axially into the inlet and, driven by the high-speed rotation of the impeller, flows radially out into the diffuser. The high-speed airflow forms a spiral trajectory in the diffuser duct. Because the airflow has a radial velocity component, the airflow primarily flows along the outer side of the duct during the downward spiral.

[0005] In the prior art, the structural design of a centrifugal fan usually regards the first-stage stationary guide vane and its base as a separate component, and the fan casing and the second-stage stationary guide vane as a whole as another component. After assembly, there is a gap between the outer edge of the first-stage stationary guide vane and the fan casing. This gap is in the high-speed airflow area of the air duct, which can easily cause an airflow bypass effect, and then induce a strong vortex phenomenon in the edge area of the impeller. These vortices not only produce obvious aerodynamic noise, but also due to their interference with the mainstream airflow, may lead to an increase in local airflow resistance, and in severe cases may even hinder the smooth flow of airflow. Under long-term operation, the continuous impact and friction of the vortex will also accelerate the wear of the first-stage stationary guide vane material in the expansion zone, thereby affecting the performance of the entire centrifugal fan and gradually reducing its working efficiency. Utility Model Content

[0006] The technical problem to be solved by the present invention is to overcome the defects in the diffuser structure of the centrifugal fan in the prior art, in which there is a gap between the outer edge of the first-stage stationary guide vane and the fan casing, which generates aerodynamic noise and reduces the working efficiency of the centrifugal fan, and to provide a diffuser structure, a centrifugal fan and a household appliance.

[0007] The utility model solves the above technical problems through the following technical solutions:

[0008] A pressure diffuser structure is installed in a centrifugal fan of a household appliance for adsorbing debris. The pressure diffuser structure includes a fan housing and a primary guide assembly and at least one secondary guide assembly arranged in sequence within the fan housing along the flow direction of the airflow. The primary guide assembly includes a primary base and a plurality of primary stationary guide vanes arranged at intervals on the circumferential surface of the primary base. The secondary guide assembly includes a secondary base and a plurality of secondary stationary guide vanes arranged at intervals on the circumferential surface of the secondary base. The primary stationary guide vanes are integrally formed with at least a portion of the fan housing, and the primary base is separately provided from the secondary base. The secondary stationary guide vanes are separately provided from the fan housing, or the secondary stationary guide vanes are integrally formed with a portion of the fan housing.

[0009] In this solution, the pressure diffuser structure is formed integrally with the first-stage stationary guide vanes and at least part of the fan housing, thereby eliminating the gap between the two (the first-stage stationary guide vanes and the fan housing). All airflow in the pressure diffuser duct flows through the interval space between the first-stage stationary guide vanes, thereby improving the flow guidance effect; at the same time, the problems of airflow short-circuiting and eddy currents are avoided, and the rectification of the airflow outside the air duct is achieved, thereby weakening the flow separation phenomenon and pressure pulsation on the surface of the first-stage stationary guide vanes (pressure pulsation refers to the uneven application of airflow pressure on the stationary guide vanes, with a more concentrated or larger pressure at a certain position, and this pressure does not last long at a single time, and may show a certain periodicity), thereby improving the airflow characteristics of the outer edge of the first-stage stationary guide vanes, improving the overall efficiency of the centrifugal fan, and reducing the fan noise. The primary and secondary bases are separated to facilitate separate processing. This significantly reduces aerodynamic noise (because the pressure of the airflow at the primary guide assembly is greater than that at the secondary guide assembly, the reduction in aerodynamic noise at the primary guide assembly is more significant than that at the secondary guide assembly). This also reduces the manufacturing difficulty of the overall structure. Furthermore, different secondary guide assemblies can be replaced or the number of guide assemblies increased as needed for the desired flow guidance effect. The secondary stationary guide vanes can be separated from the fan housing for ease of manufacturing or replacement, or they can be integrally formed to further reduce fan noise.

[0010] Preferably, a step is provided on the outer circumference of the secondary base, and the primary base is sleeved on the outer circumference of the secondary base and clamped on the step; the outer circumference of the primary base and the outer circumference of the secondary base transition smoothly at the step.

[0011] In this solution, the outer peripheral surface of the first-level base and the outer peripheral surface of the second-level base transition smoothly at the above-mentioned step, avoiding the formation of uneven surfaces on the two-level base at the step, which causes flow separation and formation of airflow vortexes, thereby avoiding the generation of aerodynamic noise and not affecting the aerodynamic performance and working efficiency of the fan.

[0012] Preferably, the first-stage stationary guide vanes and at least a portion of the fan casing are integrally formed by injection molding or 3D printing.

[0013] In this solution, injection molding or 3D printing is used to achieve integrated molding of the first-stage stationary guide vanes and at least part of the fan housing, which is a simple process and easy to implement.

[0014] Preferably, when the secondary stationary guide vanes are separately provided from the fan casing, the circumferential edges of the secondary stationary guide vanes abut against the inner surface of the fan casing.

[0015] In this solution, the circumferential edge of the secondary stationary guide vane is pressed against the inner surface of the fan casing, so that the diffuser structure eliminates the gap between the secondary stationary guide vane and the fan casing at the secondary guide assembly, further improving the guide effect and reducing aerodynamic noise, which is beneficial to improving the overall efficiency of the centrifugal fan.

[0016] Preferably, when the secondary stationary guide vane is separately arranged from the fan casing, the fan casing is provided with an arc-shaped groove on the inner surface relative to the secondary stationary guide vane, the secondary stationary guide vane is clamped in the arc-shaped groove, and the circumferential contour surface of the secondary stationary guide vane is in contact with the arc-shaped groove.

[0017] In this solution, the circumferential contour surface of the secondary stationary guide vane is pressed against the arc-shaped groove of the above-mentioned structure, so that the two (the secondary stationary guide vane and the fan casing) are highly fitted together, eliminating the gap between the two. The airflow flowing through the secondary guide assembly flows through the interval space between the secondary stationary guide vanes, further improving the guide effect and reducing aerodynamic noise, thereby improving the overall working efficiency of the diffuser structure, and enabling the fan to operate in a more stable and efficient state.

[0018] Preferably, a sealing material is filled between the arc-shaped groove and the secondary stationary guide vane.

[0019] In this solution, the sealing between the secondary stationary guide vanes and the fan housing is further improved by filling sealing material between the arc-shaped groove and the secondary stationary guide vanes; even if there is a small gap between the secondary stationary guide vanes and the fan housing due to processing errors, it can be filled with the sealing material, thereby reliably ensuring a gap-free structure.

[0020] Preferably, the secondary stationary guide vanes and a portion of the fan housing are integrally formed by injection molding or 3D printing.

[0021] In this solution, injection molding or 3D printing is used to realize the integrated molding of the two-stage guide assembly and the fan housing, which is simple in process and easy to implement.

[0022] A centrifugal fan comprises a fan housing, a moving impeller arranged in the fan housing, and a motor. The centrifugal fan also comprises a diffuser structure as described above; the bearing of the motor passes through the diffuser structure and is connected to the moving impeller, and the fan housing is connected to the fan housing.

[0023] In this solution, the centrifugal fan eliminates the gap between the first-stage static guide vane and the fan casing through the above-mentioned pressure expansion structure, improves the guide effect, improves the airflow characteristics of the outer edge of the first-stage static guide vane, improves the overall efficiency of the centrifugal fan, and reduces the fan noise.

[0024] Preferably, the surfaces of the wind cover and the fan housing at the connection point transition smoothly.

[0025] In this solution, the wind hood and the fan housing are arranged to have a smooth transition at the connection point, avoiding the formation of uneven surfaces between the wind hood and the fan housing, which causes flow separation and forms air flow vortices, thereby generating aerodynamic noise and affecting the aerodynamic performance and working efficiency of the fan.

[0026] A household appliance comprises the centrifugal fan as described above.

[0027] In this solution, the household appliance eliminates the gap between the first-stage stationary guide vane and the fan housing through the above-mentioned centrifugal fan, improves the guide effect, improves the airflow characteristics of the outer edge of the first-stage stationary guide vane, improves the overall efficiency of the centrifugal fan, and reduces the fan noise.

[0028] The positive progressive effect of the present invention is that the pressure diffuser structure, centrifugal fan and household appliance eliminate the gap between the first-stage stationary guide vane and the fan housing, thereby improving the flow guidance effect, improving the airflow characteristics of the outer edge of the first-stage stationary guide vane, improving the overall efficiency of the centrifugal fan, and reducing the fan noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the three-dimensional structure of the diffuser structure of Example 1 of the present utility model.

[0030] Figure 2 for Figure 1 Schematic diagram of the half-section structure.

[0031] Figure 3 This is a schematic diagram of the three-dimensional structure of the centrifugal fan of Example 1 of the present utility model.

[0032] Figure 4 for Figure 3 Schematic diagram of the half-section structure.

[0033] Figure 5 This is a schematic diagram of the half-section structure of the diffuser structure of Example 2 of the present utility model.

[0034] Figure 6 This is a schematic diagram of the half-section structure of the centrifugal fan of Example 2 of the present utility model.

[0035] Description of reference numerals:

[0036] Centrifugal fan 1

[0037] Windshield 2

[0038] Impeller 3

[0039] Diffuser structure 4

[0040] First-level diversion component 5

[0041] First level base 51

[0042] First stage static guide vane 52

[0043] Secondary guide component 6

[0044] Secondary base 61

[0045] Step 611

[0046] Secondary stationary guide vane 62

[0047] Fan housing 7

[0048] Upper part 71 of the fan housing

[0049] The lower part 72 of the fan housing

[0050] Motor housing 8

[0051] Airflow direction A DETAILED DESCRIPTION

[0052] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0053] Example 1

[0054] This embodiment provides a pressure diffuser structure 4 installed in a centrifugal fan 1 of a household appliance for adsorbing debris. This type of household appliance can be a cleaning appliance such as a sweeping robot, a vacuum cleaner, and a floor scrubber.

[0055] The pressure diffuser structure 4 includes a fan housing 7 and a primary guide assembly 5 and at least one secondary guide assembly 6, which are sequentially arranged within the fan housing 7 along the flow direction A of the airflow. The primary guide assembly 5 includes a primary base 51 and a plurality of primary stationary guide vanes 52 spaced apart on the circumferential surface of the primary base 51. The secondary guide assembly 6 includes a secondary base 61 and a plurality of secondary stationary guide vanes 62 spaced apart on the circumferential surface of the secondary base 61. The primary stationary guide vanes 52 are integrally formed with at least a portion of the fan housing 7, while the primary base 51 and the secondary base 61 are separate. The secondary stationary guide vanes 62 are separate from the fan housing 7, i.e., the entire secondary guide assembly 6 is separate from both the primary guide assembly 5 and the fan housing 7.

[0056] Specifically, if Figure 1 and Figure 2As shown, in this embodiment, a plurality of first-stage stationary guide vanes 52 are arranged at the same inclination angle around the circumferential surface of the first-stage base 51. Guided by the plurality of first-stage stationary guide vanes 52, the airflow passes through the gaps between the first-stage stationary guide vanes 52, converting its dynamic pressure into static pressure and reducing the airflow velocity. Similarly, a plurality of second-stage stationary guide vanes 62 are arranged at the same inclination angle around the circumferential surface of the second-stage base 61, but the inclination angle of the second-stage stationary guide vanes 62 differs from that of the first-stage stationary guide vanes 52, resulting in a different flow direction. Under the guidance of the second-stage stationary guide vanes 62, the airflow velocity is further reduced, ultimately flowing out in an axial direction. The first-stage stationary guide vanes 52 are integrally formed with the fan housing 7, while the second-stage guide assembly 6 is provided separately from the first-stage guide assembly 5 and the fan housing 7. That is, the second-stage guide assembly 6 is not integrally formed with the first-stage guide assembly 5, nor is it integrally formed with the fan housing 7; the second-stage guide assembly 6 is an independent structural component.

[0057] In other embodiments, the number of flow guide assemblies can be increased based on the need for flow guidance effect or pressure expansion or speed reduction, and multiple secondary flow guide assemblies 6 or secondary or tertiary flow guide assemblies can be provided. In other embodiments, as needed, the primary static guide vanes 52 can also be integrally formed with a portion of the fan housing 7. For example, the fan housing 7 can be divided into upper and lower parts, with only the upper fan housing 7 and the primary static guide vanes 52 being formed, while the lower fan housing 7 can still be an independent structural component.

[0058] The pressure diffuser structure 4 is formed integrally with at least a portion of the fan housing 7 through the first-stage stationary guide vanes 52, thereby eliminating the gap between the two (the first-stage stationary guide vanes 52 and the fan housing 7). All airflow in the pressure diffuser duct flows through the interval space between the first-stage stationary guide vanes 52, thereby improving the flow guidance effect; at the same time, it avoids the problems of airflow short circuit and eddy current, realizes the rectification of the airflow outside the air duct, weakens the flow separation phenomenon and pressure pulsation on the surface of the first-stage stationary guide vanes 52 (pressure pulsation refers to the uneven application of airflow pressure on the stationary guide vanes, with a more concentrated or larger pressure at a certain position, and this pressure does not last long at a single time, and may show a certain periodicity), thereby improving the airflow characteristics at the outer edge of the first-stage stationary guide vanes 52, improving the overall efficiency of the centrifugal fan 1, and reducing the fan noise. The secondary guide component 6 is separated from the primary guide component 5 and the fan housing 7, that is, the two-stage guide components and the secondary guide component 6 and the fan housing 7 are processed separately, which is convenient for manufacturing or replacing the secondary guide components 6 with different inclination angles. While significantly reducing the aerodynamic noise (because the pressure of the airflow at the primary guide component 5 is greater than the pressure of the airflow at the secondary guide component 6, the reduction of aerodynamic noise at the primary guide component 5 is more significant than that at the secondary guide component 6), it also reduces the manufacturing difficulty of the overall structure. Different secondary guide components 6 can also be replaced or the number of guide components can be increased according to the needs of the guide effect.

[0059] Among them, such as Figure 2 As shown, the circumferential edge of the secondary stationary guide vane 62 abuts against the inner surface of the fan casing 7, so that the diffuser structure 4 eliminates the gap between the secondary stationary guide vane 62 and the fan casing 7 at the secondary guide assembly 6, further improving the guide effect and reducing aerodynamic noise, which is beneficial to improving the overall efficiency of the centrifugal fan 1.

[0060] The mating structure between the secondary stationary guide vanes 62 and the inner surface of the fan housing 7 can be implemented in a variety of ways, not limited to the aforementioned abutment method. For example, in other embodiments, the fan housing 7 may be provided with an arcuate groove (not shown) on its inner surface relative to the secondary stationary guide vanes 62. The secondary stationary guide vanes 62 are retained in the arcuate groove, with the circumferential contour of the secondary stationary guide vanes abutting against the arcuate groove. This creates a high degree of fit between the secondary stationary guide vanes 62 and the fan housing 7, eliminating any gaps between them. This further enhances the flow guidance effect, reduces aerodynamic noise, and improves the overall operating efficiency of the diffuser structure, enabling the fan to operate more smoothly and efficiently.

[0061] In addition, a sealing material can be filled between the arc-shaped groove and the secondary stationary guide vane 62 to further improve the sealing between the secondary stationary guide vane 62 and the fan housing 7; even if there is a small gap between the secondary stationary guide vane 62 and the fan housing 7 due to processing errors, it can be filled with the sealing material, thereby reliably ensuring a gap-free structure.

[0062] Among them, such as Figure 2 As shown, a step 611 is provided on the outer circumference of the secondary base 61, and the primary base 51 is sleeved on the outer circumference of the secondary base 61 and clamped on the step 611; the outer circumference of the primary base 51 and the outer circumference of the secondary base 61 smoothly transition at the step 611. That is, the outer diameter of the primary base 51 is equal to the outer diameter of the secondary base 61, and the primary base 51 is completely placed in the concave space formed by the step 611, so that when the primary base 51 transitions to the secondary base 61, the outer surfaces of the two bases are flush at this step 611 and do not protrude outward. When the airflow passes through this step 611, it will not generate local small vortices due to the uneven surface, thereby generating noise. It should be noted here that for the purpose of structural display, Figure 2 The first-level base 51 is not shown to be completely placed in the concave space of the step 611, but in fact, by adjusting the size of the first-level base 51 or the step 611, the first-level base 51 can be completely placed in the concave space at the step 611, so that the outer surfaces of the two bases are smoothly transitioned.

[0063] In such a structure, the outer peripheral surface of the first-level base 51 and the outer peripheral surface of the second-level base 61 smoothly transition at the above-mentioned step 611, avoiding the formation of uneven surfaces between the two-level bases at the step 611, resulting in flow separation and formation of airflow vortices, thereby avoiding the generation of aerodynamic noise and not affecting the aerodynamic performance and working efficiency of the fan.

[0064] The first-stage stationary guide vanes 52 and the fan housing 7 are integrally formed by injection molding or 3D printing. The use of injection molding or 3D printing technology to achieve integral molding is simple and easy to implement.

[0065] This embodiment also provides a centrifugal fan 1, such as Figure 3 and Figure 4 As shown, the centrifugal fan 1 includes a fan housing 2, a moving impeller 3 arranged in the fan housing 2, and a motor (not shown in the figure, the position of the motor is Figure 3 and Figure 4The centrifugal fan 1 comprises a plurality of components, each comprising a plurality of first-stage static guide vanes 52 and a plurality of second-stage static guide vanes 52. The components are positioned at the motor housing 8, and the diffuser structure 4 is described above. The motor bearing (not shown) passes through the diffuser structure 4 and connects to the impeller 3. The fan housing 2 is connected to the fan housing 7. The diffuser structure 4 eliminates the gap between the first-stage static guide vanes 52 and the fan housing 7, improving the flow guidance effect and the airflow characteristics at the outer edges of the first-stage static guide vanes 52. This improves the overall efficiency of the centrifugal fan 1 and reduces fan noise.

[0066] Among them, such as Figure 4 As shown, the surface of the air hood 2 and the fan housing 7 at the connection point has a smooth transition, which avoids the formation of uneven surfaces between the air hood 2 and the fan housing 7 and the occurrence of flow separation, the formation of air flow vortexes, and the generation of aerodynamic noise, which affects the aerodynamic performance and working efficiency of the fan.

[0067] Example 2

[0068] This embodiment provides another diffuser structure 4, such as Figure 5 As shown, the diffuser structure 4 of this embodiment is substantially the same as the diffuser structure 4 of Example 1, except that the fan casing 7 is divided into two parts, the first-stage stationary guide vanes 52 are integrally formed with the upper part 71 of the fan casing, and the second-stage stationary guide vanes 62 are integrally formed with the lower part 72 of the fan casing.

[0069] Some technical effects of the pressure diffuser structure 4 are the same as those of the pressure diffuser structure 4 of Example 1. By integrally forming the first-stage stationary guide vanes 52 and the upper part 71 of the fan housing, the gap between the two (the first-stage stationary guide vanes 52 and the fan housing 7) is eliminated, and all airflow in the pressure diffuser duct flows through the interval space between the first-stage stationary guide vanes 52, thereby improving the guide effect; at the same time, the problems of airflow short circuit and eddy current are avoided, and the rectification effect of the airflow outside the air duct is achieved, which weakens the flow separation phenomenon and pressure pulsation on the surface of the first-stage stationary guide vanes 52, thereby improving the airflow characteristics of the outer edge of the first-stage stationary guide vanes 52, improving the overall efficiency of the centrifugal fan 1, and reducing the fan noise.

[0070] Furthermore, the diffuser structure 4 of this embodiment is integrally formed with the lower portion 72 of the fan housing via the secondary static guide vanes 62. This eliminates the gap between the secondary static guide vanes 62 and the fan housing 7 at the secondary guide assembly 6, further enhancing the airflow guidance effect and reducing aerodynamic noise, thereby improving the overall efficiency of the centrifugal fan 1. Furthermore, by dividing the fan housing 7 into two parts, one integrally formed with the primary static guide vanes 52 and the other with the secondary static guide vanes 62, the manufacturing difficulty is reduced compared to the case where two-stage guide assemblies are integrally formed with the fan housing 7. Furthermore, different secondary guide assemblies 6 can be replaced or the number of guide assemblies can be increased, depending on the desired airflow guidance effect.

[0071] In this embodiment, the secondary stationary guide vanes 62 and the lower portion 72 of the fan housing can also be integrally formed by injection molding or 3D printing. In this way, the upper and lower portions of the fan housing 7 are both integrally formed structures, and both are integrally formed using injection molding or 3D printing, which is simple and easy to manufacture.

[0072] This embodiment also provides a centrifugal fan 1, such as Figure 6 As shown, the centrifugal fan 1 of this embodiment is substantially the same as the centrifugal fan 1 of Example 1, except that the pressure diffuser structure 4 is different, that is, the centrifugal fan 1 of this embodiment adopts the pressure diffuser structure 4 of this embodiment, and the pressure diffuser structure 4 of this embodiment is different from the pressure diffuser structure 4 of Example 1.

[0073] Like the centrifugal fan 1 of Example 1, the surface of the wind hood 2 and the fan housing 7 at the connection point has a smooth transition, which avoids the formation of uneven surfaces between the wind hood 2 and the fan housing 7 and the occurrence of flow separation, the formation of air flow vortices, and the generation of aerodynamic noise, which affects the aerodynamic performance and working efficiency of the fan.

[0074] Example 3

[0075] This embodiment provides a household appliance, which may be a cleaning appliance such as a robot vacuum, vacuum cleaner, or floor scrubber. The household appliance includes a centrifugal fan 1 as described in Example 1 or Example 2. By using the centrifugal fan 1 of Example 1 or Example 2, the household appliance eliminates the gap between the first-stage stationary guide vanes 52 and the fan housing 7, thereby enhancing the airflow guidance effect, improving the airflow characteristics at the outer edges of the first-stage stationary guide vanes 52, increasing the overall efficiency of the centrifugal fan 1, and reducing fan noise.

[0076] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of protection of the present invention.

Claims

1. A pressure diffuser structure, installed in a centrifugal fan of a household appliance for adsorbing debris, the pressure diffuser structure comprising a fan housing and a primary guide assembly and at least one secondary guide assembly disposed sequentially within the fan housing and along the flow direction of an airflow, the primary guide assembly comprising a primary base and a plurality of primary stationary guide vanes disposed at intervals on a circumferential surface of the primary base, and the secondary guide assembly comprising a secondary base and a plurality of secondary stationary guide vanes disposed at intervals on a circumferential surface of the secondary base; It is characterized by: The first-stage stationary guide vane is integrally formed with at least a portion of the fan housing, and the first-stage base and the second-stage base are separately provided; The secondary static guide vanes are separately provided from the fan housing, or the secondary static guide vanes are integrally formed with a portion of the fan housing.

2. The pressure diffuser structure according to claim 1, wherein: A step is provided on the outer circumference of the secondary base, and the primary base is sleeved on the outer circumference of the secondary base and clamped on the step; the outer circumference of the primary base and the outer circumference of the secondary base transition smoothly at the step.

3. The pressure diffuser structure according to claim 1, wherein: The first-stage stationary guide vanes and at least a portion of the fan housing are integrally formed by injection molding or 3D printing.

4. The pressure diffuser structure according to claim 1, wherein: When the secondary stationary guide vanes are separately provided from the fan housing, the circumferential edges of the secondary stationary guide vanes abut against the inner surface of the fan housing.

5. The pressure diffuser structure according to claim 1, wherein: When the secondary stationary guide vane is separately arranged from the fan casing, the fan casing is provided with an arc-shaped groove on the inner surface relative to the secondary stationary guide vane, the secondary stationary guide vane is clamped in the arc-shaped groove, and the circumferential contour surface of the secondary stationary guide vane is in contact with the arc-shaped groove.

6. The pressure diffuser structure according to claim 5, characterized in that: A sealing material is also filled between the arc-shaped groove and the secondary stationary guide vane.

7. The pressure diffuser structure according to claim 1, wherein: The secondary stationary guide vanes and a portion of the fan housing are integrally formed by injection molding or 3D printing.

8. A centrifugal fan comprising a fan housing, a moving impeller arranged in the fan housing, and a motor, wherein: The centrifugal fan further comprises a pressure diffuser structure according to any one of claims 1 to 7; The bearing of the motor passes through the diffuser structure and is connected to the impeller, and the wind cover is connected to the fan housing.

9. The centrifugal fan according to claim 8, wherein: The surfaces of the wind cover and the fan housing at the connection point are smoothly transitioned.

10. A household appliance, characterized in that: The household appliance includes the centrifugal fan according to claim 8 or 9.

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