Impeller, centrifugal fan and cleaning equipment

Abstract

The utility model discloses an impeller, a centrifugal fan and cleaning equipment, and belongs to the technical field of fans. The impeller comprises a first end cover, a second end cover and a plurality of blades arranged between the first end cover and the second end cover, the second end cover is provided with an air inlet, the central axis of the impeller is located in the middle of the blades, and the central axis of the impeller is located in the middle of the air inlet. The blades are backward bending blades, and the backward bending angles alpha of the blades are between 58 degrees and 64 degrees; the ratio of the diameter d of the air inlet to the outer diameter D of the impeller ranges from 0.36 to 0.44, and the outer diameter D of the impeller ranges from 40 mm to 48 mm. According to the utility model, the impeller adopts the backward bending type blade, so that the energy consumption is lower, the efficiency is higher, and the fan can keep higher vacuum degree for a longer time; the rear bending angles of the blades are arranged between 58 degrees and 64 degrees, and the ratio range of the diameter of the air inlet to the diameter of the impeller is controlled between 0.36 and 0.44, so that the vacuum degree of the fan can be improved, and the cleaning capacity of the cleaning equipment can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fans, in particular to an impeller, a centrifugal fan and a cleaning device. Background Art

[0002] With the rapid development of technology, cleaning devices such as floor sweeping robots and dust collectors have been widely used. These cleaning devices generate negative pressure by using a fan, effectively sucking dust, fine particles, etc. on the ground or other areas into the dust collection device, thus realizing efficient and convenient cleaning work. These cleaning devices improve the efficiency and quality of cleaning work and also bring a comfortable and healthy living environment to people.

[0003] The negative pressure value of the fan is one of the important indicators of the cleaning ability of the cleaning device. It represents the magnitude of the suction force generated by the fan inside the cleaning device and has an important impact on the adsorption ability of the cleaning device to adsorb dust, debris and other sundries. Although the negative pressure value of the cleaning devices in the related technologies can meet the basic daily cleaning requirements, the vacuum degree of the fan is still limited, and the cleaning power of the cleaning device still needs to be improved. Summary of the Utility Model

[0004] The purpose of the embodiments of the utility model is to provide an impeller, a centrifugal fan and a cleaning device. By optimizing the design of the impeller, the vacuum degree of the fan can be improved, and the cleaning power of the cleaning device can be enhanced.

[0005] To achieve the above object, the utility model adopts the following technical solutions:

[0006] An impeller includes a first end cover, a second end cover and a plurality of blades disposed between the first end cover and the second end cover. The second end cover is provided with an air inlet, the central axis of the impeller is located among the plurality of blades, and the central axis of the impeller is located in the middle of the air inlet;

[0007] The blades are backward curved blades, and the backward bend angle α of the blades is between 58 degrees and 64 degrees;

[0008] The ratio of the diameter d of the air inlet to the outer diameter D of the impeller is between 0.36 and 0.44;

[0009] The outer diameter D of the impeller (10) is between 40 mm and 48 mm.

[0010] Optionally, the impeller has an air outlet, the air outlet is located between the first end cover, the second end cover and adjacent blades, and the ratio of the height h of the air outlet to the outer diameter D of the impeller is between 0.026 and 0.086.

[0011] Optionally, the number of blades provided between the first end cover and the second end cover is 9 to 11.

[0012] Optionally, the backward bend angle α of the blade is between 59 degrees and 63 degrees;

[0013] And / or, the ratio of the diameter d of the air inlet to the outer diameter D of the impeller is between 0.37 and 0.43;

[0014] And / or, the ratio of the height h of the air outlet to the outer diameter D of the impeller is between 0.036 and 0.076;

[0015] And / or, the diameter d of the air inlet is between 16.3 mm and 19.7 mm;

[0016] And / or, the outer diameter D of the impeller is 42.6 mm to 46.6 mm.

[0017] Optionally, the backward bend angle α of the blade is 59 degrees to 61 degrees;

[0018] And / or, the ratio of the diameter d of the air inlet to the outer diameter D of the impeller is between 0.393 and 0.413;

[0019] And / or, the ratio of the height h of the air outlet to the outer diameter D of the impeller is between 0.0465 and 0.0665;

[0020] And / or, the diameter d of the air inlet (101) is between 17 mm and 19 mm;

[0021] And / or, the outer diameter D of the impeller (10) is between 43.6 mm and 45.6 mm

[0022] And / or, the height h of the air outlet (102) is between 1.52 mm and 3.52 mm.

[0023] A centrifugal fan, comprising an impeller as described in the above solution, and further comprising a volute; the volute has an inner cavity, and the impeller is arranged in the inner cavity.

[0024] Optionally, a casing inlet and a casing outlet are provided on two adjacent sides of the volute, the casing inlet is communicated with the inner cavity, and the casing outlet is communicated with the inner cavity; the position of the casing inlet corresponds to the position of the air inlet of the impeller;

[0025] The inner cavity includes a main channel section and a diffuser section; in the main channel section, the minimum distance Tmin between the inner wall of the volute and the outer circumference of the impeller is between 5.27 mm and 7.13 mm; the maximum distance Tmax between the inner wall of the volute and the outer circumference of the impeller is between 7.48 mm and 10.12 mm;

[0026] The diffuser section has a divergence angle β, and the divergence angle β is between 8 degrees and 16 degrees;

[0027] The bevel angle of the housing outlet is γ, and the bevel angle γ is between 8 degrees and 20 degrees; the plane where the housing outlet is located is the first plane, the plane on the side of the diffuser section of the volute that is away from the central axis is the second plane, and the plane perpendicular to the second plane is the third plane. The included angle between the first plane and the third plane is the bevel angle γ.

[0028] Optionally, the Tmin is between 5.58 mm and 6.82 mm, and the Tmax is between 7.92 mm and 9.68 mm;

[0029] The diffuser section has a divergence angle β, and the divergence angle β is between 8.46 degrees and 9.68 degrees;

[0030] The bevel angle of the housing outlet is γ, and the bevel angle γ is between 13.5 degrees and 16.5 degrees.

[0031] Optionally, the Tmin is 6.2 mm, and the Tmax is 8.8 mm;

[0032] The diffuser section has a divergence angle β, and the divergence angle β is 9.4 degrees;

[0033] The bevel angle of the housing outlet is γ, and the bevel angle γ is 15 degrees;

[0034] The centrifugal fan further includes a motor, the output shaft of the motor is connected to the impeller, and the motor is used to drive the impeller to rotate; when the driving power of the motor is between 70 w and 80 w, the vacuum degree of the impeller is 15 kPa.

[0035] A cleaning device includes the centrifugal fan as described in the above solution.

[0036] The beneficial effects of the present utility model are as follows: In the impeller and the centrifugal fan, the impeller adopts backward-curved blades. The backward-curved blades have lower energy consumption and higher efficiency, which is beneficial for the fan to maintain a relatively high vacuum degree for a long time. The backward-curved angle of the blades is set between 58 degrees and 64 degrees, and the ratio range of the inlet diameter to the impeller diameter is controlled between 0.36 and 0.44, optimizing the impeller design and improving the vacuum degree of the fan. The cleaning power of the cleaning device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The following further describes the present utility model in detail according to the drawings and embodiments.

[0038] Figure 1 It is a schematic diagram of the overall structure of the impeller according to the embodiment of the present utility model;

[0039] Figure 2 It is a cross-sectional view of the impeller according to the embodiment of the present utility model;

[0040] Figure 3 is Figure 2 the enlarged view of part A in

[0041] Figure 4 It is a longitudinal sectional view of the impeller according to the embodiment of the present utility model;

[0042] Figure 5 It is one of the overall structural schematic diagrams of the centrifugal fan according to the embodiment of the present utility model (the power device is omitted in the figure);

[0043] Figure 6 It is the other overall structural schematic diagram of the centrifugal fan according to the embodiment of the present utility model (the power device is omitted in the figure);

[0044] Figure 7 It is one of the sectional views of the centrifugal fan according to the embodiment of the present utility model;

[0045] Figure 8 It is the side view of the centrifugal fan according to the embodiment of the present utility model;

[0046] Figure 9 It is the internal schematic diagram of the volute of the centrifugal fan according to the embodiment of the present utility model (part of the volute is omitted);

[0047] Figure 10 It is the difference between the structural design of the centrifugal fan according to the embodiment of the present utility model and the structural design of the traditional fan;

[0048] Figure 11 It is the difference in experimental data between the centrifugal fan according to the embodiment of the present utility model and the traditional fan.

[0049] In the figure: 10. impeller; 101. air inlet; 102. air outlet; 103. central axis; 11. first end cover; 12. second end cover; 121. outer edge part; 122. central part; 13. blade; 131. inner end of blade; 132. outer end of blade; 133. outer wall surface; 20. volute; 201. volute inlet; 202. volute outlet; 203. inner wall surface; 21. main channel section; 22. outer expansion section. Detailed implementation manners

[0050] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present utility model clearer, the technical solutions of the embodiments of the present utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model.

[0051] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected" and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0052] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0053] With the acceleration of the modern life rhythm and the increasing work pressure, cleaning devices such as floor sweeping robots, vacuum cleaners, and mite removers are widely used, liberating people from tedious daily cleaning work such as sweeping the floor. Taking the floor sweeping robot as an example, when the floor sweeping robot is cleaning, it generally uses a rolling brush and a side brush to rotate at high speed to sweep in the garbage, and then through the vacuum negative pressure generated by the blower, the dust and garbage on the surface are sucked into the machine to complete the cleaning work.

[0054] Currently, the intelligent level of cleaning devices is the focus that various manufacturers compete to pursue and innovate, such as improving the environmental detection and autonomous navigation planning capabilities of cleaning robots. However, for cleaning devices, the cleaning ability is the core ability. In related technologies, the performance of the blower of the cleaning device is limited, resulting in limited cleaning ability of the cleaning robot.

[0055] Cleaning devices such as floor sweeping robots generally use centrifugal fans. According to the principle of converting kinetic energy into potential energy, a centrifugal fan uses a high-speed rotating impeller to accelerate the gas, and then decelerates and changes the flow direction to convert kinetic energy into potential energy (pressure). In a single-stage centrifugal fan, the gas enters the impeller from the axial air inlet. When the gas flows through the impeller, under the action of centrifugal force, the gas is pushed out of the impeller through the radial air outlet and then enters the diffuser. In the diffuser, the gas changes the flow direction and the cross-sectional area of the pipeline increases, causing the air flow to decelerate. This deceleration converts kinetic energy into pressure energy. The increase in air flow pressure mainly occurs in the impeller and secondly in the diffusion process. A centrifugal fan is a type of centrifugal fan, mainly composed of a volute, an impeller, a motor, etc. The volute is an important diffuser component of the fan. The impeller is arranged inside the volute. When the gas enters the internal channel of the volute from the air outlet of the impeller, the flow rate of the gas gradually decreases, the dynamic pressure decreases while the static pressure increases, thus realizing the conversion of gas kinetic energy and the increase in pressure. The gas after being diffused by the volute is discharged from the outlet of the volute, completing the entire gas transportation process.

[0056] Currently, in cleaning devices such as floor sweeping robots, the maximum negative pressure value that the adopted fan can reach is generally only about 12 kPa, the vacuum degree is not high, the cleaning ability of the cleaning device is limited, and the ability to suck up garbage and sundries is limited.

[0057] To improve this problem, the present application provides an impeller, a centrifugal fan using the impeller, and a cleaning device using the centrifugal fan to increase the negative pressure degree of the fan, thereby enhancing the cleaning ability of the cleaning device.

[0058] In one embodiment, through the structural optimization and mutual matching of the impeller and the volute, the overall performance of the centrifugal fan is improved. It can achieve a vacuum degree (negative pressure value) of 15 kPa for the fan when the driving power of the motor is 70 w. Figure 11 provided relevant experimental data. Refer to Figure 10 、 Figure 11 Compared with three traditional fans, the negative pressure value of the vacuum degree fan of the present application is increased under the highest negative pressure condition, and the cleaning ability of the fan is improved.

[0059] Please refer to Figures 1 to 9 Below, the structure of the impeller 10 and the centrifugal fan will be described. The centrifugal fan includes an impeller 10, a volute 20, and a power device (not shown in the figure). The impeller 10 is arranged inside the volute 20, and the power device is used to drive the impeller 10 to rotate. The power device can be, but is not limited to, a motor, and can drive the impeller 10 to rotate by connecting the motor shaft to the first end cover 11.

[0060] Please continue to refer to Figure 1 、 Figure 4, the impeller 10 includes a first end cover 11, a second end cover 12, and a plurality of blades 13. The impeller 10 has a central axis 103, and the first end cover 11 and the second end cover 12 are spaced apart in the direction of the central axis 103. The plurality of blades 13 are disposed between the first end cover 11 and the second end cover 12. The impeller 10 is provided with an air inlet 101 and an air outlet 102, and the air inlet 101 is provided at the middle position of the second end cover 12. Refer to Figure 2 , the plurality of blades 13 are spaced apart around the central axis 103, and the air outlet 102 is located between the first end cover 11, the second end cover 12, and two adjacent blades 13. Refer to Figure 4 , Figure 9 , the central axis 103 is located in the middle of the plurality of blades 13, and moreover, the central axis 103 is located in the middle of the air inlet 101, and the central axis 103 passes through the air inlet 101.

[0061] The blades 13 of the impeller 10 adopt a backward-curved design. The bending direction of the backward-curved blades 13 is opposite to the rotation direction of the impeller 10. Taking Figure 2 as an example, the blade 13 is bent clockwise, and the impeller 10 is configured to rotate counterclockwise. In the figure, ω indicates the rotational angular velocity of the impeller 10. The backward-curved design of the blade 13 makes the adhesion of the fluid on the blade 13 better, reduces the flow loss, can obtain better fan efficiency, and takes into account both efficiency and negative pressure value.

[0062] Refer to Figure 3 , the backward-curved angle of the blade 13 is α, the diameter of the air inlet 101 of the impeller 10 is d, the height of the air outlet 102 of the impeller 10 is h, and the outer diameter of the impeller 10 is D.

[0063] Refer to Figure 2 , Figure 3 , the backward-curved angle α of the blade 13 is determined in the following manner: One end of the blade 13 close to the central axis 103 is the leading end of the blade, and the end far from the central axis 103 is the outer end 132 of the blade. The outer end 132 of the blade is flush with or close to the outer peripheral edge of the first end cover 11; the backward-curved angle of the blade 13 is determined by a first reference line and a second reference line. The first reference line passes through the central axis 103 of the impeller 10 and the outer end 132 of the blade. The second reference line is tangent to the area of the convex arc surface of the blade 13 close to the outer end 132. The included angle between the first reference line and the second reference line is the backward-curved angle.

[0064] Refer to Figure 4 , the diameter d of the air inlet 101 of the impeller 10 refers to the radial dimension of the air inlet 101. Continue to refer to Figure 4, the height h of the air outlet 102 of the impeller 10 refers to the axial dimension of the air outlet 102; optionally, the height of the air outlet 102 of the impeller 10 is the distance between the outer edge of the first end cover 11 and the outer edge of the second end cover 12. The outer diameter D of the impeller 10 refers to the dimension of the whole impeller 10 in the radial direction; optionally, the first end cover 11 and the second end cover 12 are coaxially arranged, the diameters of the first end cover 11 and the second end cover 12 are the same, and the outer diameter D of the impeller 10 is equal to the diameter of the end cover.

[0065] In this application, the backward bend angle α of the blade 13 is between 58 degrees and 64 degrees, that is, 58° ≤ α ≤ 64°. And, the ratio of the diameter d of the air inlet 101 to the outer diameter D of the impeller 10 is between 0.36 and 0.44, that is, 0.36 ≤ d / D ≤ 0.44. Through the design of the backward bend angle, combined with the design of the ratio of the diameter of the air inlet 101 to the diameter of the impeller 10, when the impeller 10 is applied to a blower, it is beneficial to improve the performance of the impeller 10, thereby improving the vacuum degree and negative pressure value of the blower, and enhancing the cleaning power of the cleaning equipment.

[0066] And, the outer diameter D of the impeller 10 is between 40 mm and 48 mm. Within this range of the outer diameter D of the impeller, through

[0067] Among them, 58° ≤ α ≤ 64°, the range of the backward bend angle α is reasonable, and on the basis of this range, the blower can have higher efficiency. The larger the backward bend angle, the higher the blower efficiency, and the greater the circumferential speed of the outer circle of the impeller 10 required to reach the same vacuum degree.

[0068] 0.36 ≤ d / D ≤ 0.44, the range of d / D is reasonable, which can avoid the diameter of the air inlet 101 being too large, so as to ensure that when reaching a higher vacuum degree, the blower consumes less power, which is beneficial to improving the blower efficiency. On the basis of this range, the larger d / D is, the greater the air volume of the blower is, which is beneficial to enhancing the dust suction ability of the cleaning equipment.

[0069] In one embodiment, the backward bend angle α of the blade 13 is between 59 degrees and 63 degrees.

[0070] Optionally, the backward bend angle α of the blade 13 is between 59 degrees and 61 degrees.

[0071] Optionally, the backward bend angle α of the blade 13 is 60 degrees.

[0072] In one embodiment, the ratio d / D of the diameter d of the air inlet 101 to the outer diameter D of the impeller 10 is between 0.37 and 0.43.

[0073] Optionally, the ratio d / D of the diameter d of the air inlet 101 to the outer diameter D of the impeller 10 is between 0.393 and 0.413.

[0074] Optionally, d / D is 0.403.

[0075] In one embodiment, the outer diameter D of the impeller 10 is between 41 mm and 46 mm.

[0076] Optionally, the diameter d of the air inlet 101 is 18 mm ± 1.7 mm, and the outer diameter D of the impeller 10 is 44.6 mm ± 2 mm. It should be noted that when describing "a certain value is a ± b" in this application, it means that the value is greater than or equal to a - b and less than or equal to a + b. It should be noted that in other embodiments, the values of d and D can also be in other ranges.

[0077] In one embodiment, in addition to optimizing the impeller 10 by means of the backward bend angle α of the blade 13 and the ratio of the diameter d of the air inlet 101 to the outer diameter D of the impeller 10, the impeller 10 is also controlled by the ratio of the height h of the air outlet 102 to the outer diameter D of the impeller 10. The height of the air outlet 102 of the impeller 10 affects both the air volume of the fan and the fan efficiency. The larger the ratio of h to D, the larger the air volume of the air outlet and the higher the efficiency, but the power consumed to reach the same vacuum degree increases. In this application, by controlling the ratio of d / D within a certain range, both the fan efficiency and the improvement of the vacuum degree are taken into account.

[0078] In this embodiment, the ratio h / D of the height h of the air outlet 102 to the outer diameter D of the impeller 10 is between 0.026 and 0.086, that is, 0.026 ≤ h / D ≤ 0.086.

[0079] Optionally, the ratio h / D of the height h of the air outlet 102 to the outer diameter D of the impeller 10 is between 0.036 and 0.076.

[0080] Optionally, the ratio h / D of the height h of the air outlet 102 to the outer diameter D of the impeller 10 is between 0.0465 and 0.0665.

[0081] Optionally, the ratio of the height h of the air outlet 102 to the outer diameter D of the impeller 10 is 0.0565.

[0082] In one embodiment, the number range of the blades 13 provided in the impeller 10 is 9 to 11. The reasonable number of blades 13 is crucial for the influence of the fan efficiency. The configuration of this embodiment can achieve a higher efficiency of the fan, so that the fan can reach a higher negative pressure degree under the same driving power and improve the cleaning power of the cleaning device.

[0083] In one embodiment, the diameter d of the air inlet 101 is between 17 mm and 19 mm.

[0084] In one embodiment, the outer diameter D of the impeller 10 is between 43.6 mm and 45.6 mm.

[0085] In one embodiment, the height h of the air outlet 102 is between 1.52 mm and 3.52 mm.

[0086] Optionally, the number of blades 13 provided in the wheel is 9, 10 or 11.

[0087] In one embodiment, the overall shape of the first end cover 11 is disc-shaped or approximately disc-shaped. The second end cover 12 includes a central portion 122 and an outer edge portion 121 surrounding the central portion 122. The outer edge portion 121 and the first end cover 11 are arranged at an axial interval, and the outer edge portion 121 and the first end cover 11 are parallel or approximately parallel to cooperate to define the air outlet 102, making the air outlet smoother. The central portion 122 is approximately trumpet-shaped, and the air inlet 101 is arranged in the central area of the central portion 122. The part of the central portion 122 where the air inlet 101 is provided is located on the side of the connection between the central portion 122 and the outer edge portion 121 that is away from the first end cover 11. The inner diameter of the central portion 122 gradually increases from the air inlet 101 to the side close to the first end cover 11, and the inner surface of the central portion 122 is a curved surface. It can be understood that the central portion 122 of the second end cover 12 near the air inlet side is approximately trumpet-shaped, and the curved surface on the inner side of the central portion 122 can more effectively guide the gas into the impeller 10, reduce the deflection and turbulence of the air flow when entering the impeller 10, improve the stability and uniformity of the air flow, reduce the air flow loss, and thus improve the overall efficiency and vacuum degree of the fan.

[0088] In one embodiment, one end of the blade 13 close to the central axis 103 is the inner end 131 of the blade, and the end away from the central axis 103 is the outer end 132 of the blade. The inner end 131 of the blade is located outside the area of the air inlet 101, and the outer end 132 of the blade extends to the area close to the outer edges of the first end cover 11 and the second end cover 12 to cooperate to define the air outlet 102. From the inner end 131 to the outer end 132 of the blade, the height of the blade 13 gradually decreases.

[0089] It should be noted that the descriptions of the shapes of the first end cover 11, the second end cover 12, and the blade 13 above are not the only limitations of this application.

[0090] Next, please continue to refer to Figures 5 to 9 to continue the description of the volute 20 in the centrifugal fan and the cooperation between the impeller 10 and the volute 20.

[0091] In one embodiment, the volute 20 is a volute 20 with a radial involute and an axial involute. That is, the shape of the inner wall surface 203 of the volute 20 is extended based on the radial involute and the axial involute, which helps the uniform distribution and stable flow of the air flow inside the volute 20, reduces eddy currents and energy losses, helps improve the static pressure recovery ability of the fan, and the enhancement of the static pressure recovery ability helps improve the air extraction ability of the fan. When the fan is operating, it can more effectively suck in, compress and transport the gas, thereby maintaining or increasing the vacuum degree.

[0092] The volute 20 has an inner cavity, and the impeller 10 is arranged in the inner cavity. The power device is omitted in the drawings and not shown; exemplarily, the power device is a motor, and the output shaft of the motor extends into the volute 20 through the shaft hole on the lower side of the volute 20 to be connected to the first end cover 11 of the impeller 10 so as to transmit torque to the impeller 10 and drive the impeller 10 to rotate.

[0093] The shell inlet 201 and the shell outlet 202 are arranged on adjacent sides, and both the shell inlet 201 and the shell outlet 202 are communicated with the inner cavity. Refer to Figure 5 , the position of the shell inlet 201 corresponds to the position of the air inlet 101 of the impeller 10. The shell inlet 201 is used to provide a clearance for the air inlet 101 of the impeller 10. The air flow enters the inside of the impeller 10 through the air inlet 101 of the impeller 10. When the impeller 10 rotates, the gas passes through the channels between adjacent two blades 13 and then is pushed out to the volute 20 through the air outlet 102 of the impeller 10. The inner cavity of the volute 20 has a main channel section 21 and an expansion section. The volute tongue of the volute 20 is arranged in the main channel section 21, and the shell outlet 202 is located at the end of the expansion section. The gas enters the main channel section 21 from the impeller 10, passes through the main channel section 21 and is sent to the expansion section, and finally is sent out from the shell outlet 202 of the volute 20.

[0094] In one embodiment, please refer to Figure 7 , in the volute 20, from the volute tongue to the outer expansion section 22 of the volute 20 and the shell outlet 202, the distance between the outer circumference of the impeller 10 and the inner wall of the volute 20 gradually increases.

[0095] Please continue to refer to Figure 7 , in the main channel section 21 of the volute 20, the distance between the inner wall of the volute 20 and the outer circumference of the impeller 10 is T. In the drawings, the inner wall of the volute 20 is the inner wall surface 203, and the outer circumference of the impeller 10 is the outer wall surface 133. The minimum distance Tmin between the inner wall of the volute 20 and the outer circumference of the impeller 10 is between 5.27 mm and 7.13 mm; the maximum distance Tmax between the inner wall of the volute 20 and the outer circumference of the impeller 10 is between 7.48 mm and 10.12 mm.

[0096] Exemplarily, as Figure 7As shown, both the third reference line L3 and the fourth reference line L4 pass through the central axis 103 of the impeller 10, and the third reference line L3 is perpendicular to the fourth reference line L4. The third reference line passes through or near the volute tongue. The distance between the intersection point of the outer wall surface 133 of the impeller 10 and the third reference line L3 and the intersection point of the inner wall surface 203 of the volute 20 and the third reference line L3 is Tmin; the fourth reference line is close to the expansion section, and the distance between the intersection point of the outer wall surface 133 of the impeller 10 and the fourth reference line L4 and the intersection point of the inner wall surface 203 of the volute 20 and the fourth reference line L4 is Tmax.

[0097] Among them, the minimum distance Tmin between the outer circumference of the impeller 10 and the inner wall of the volute 20 will have an important impact on the fan noise. When other parameters remain unchanged, the smaller Tmin is, the greater the fan noise will be. The maximum distance Tmax between the outer circumference of the impeller 10 and the inner wall of the volute 20 will affect the overall size of the whole machine and is limited by the overall size of the whole machine. In this embodiment, Tmin and Tmax are controlled within the foregoing ranges, taking into account the requirements of high efficiency, compactness, and low noise of the fan, and improving the practicability of the fan.

[0098] Optionally, the minimum distance Tmin between the inner wall of the volute 20 and the outer circumference of the impeller 10 is between 5.58 mm and 6.82 mm; the maximum distance Tmax between the inner wall of the volute 20 and the outer circumference of the impeller 10 is between 7.92 mm and 9.68 mm.

[0099] Optionally, the minimum distance Tmin between the inner wall of the volute and the outer circumference of the impeller 10 is 6.2 mm; the maximum distance Tmax between the inner wall of the volute 20 and the outer circumference of the impeller 10 is 8.8 mm.

[0100] In one embodiment, please refer to Figure 8 , the expansion section of the volute 20 is located behind the main channel section 21 and is used to further guide the air flow and reduce its flow velocity and increase the static pressure. The expansion section has an expansion angle β, and the expansion angle β is between 8 degrees and 16 degrees. Controlling the expansion angle within this range is beneficial to taking into account various requirements such as high efficiency, compactness, and high vacuum degree of the fan. It can be understood that in order to achieve the same expansion effect, the larger the expansion angle is, the larger the overall size of the volute 20 required will be.

[0101] It can be understood that referring to Figure 8 、 Figure 9 , the top plate of the volute 20 is the air inlet side, and the top plates of the volute 20 in the two regions of the main channel section 21 and the expansion section 22 are flush. The bottom plate of the volute 20 in the expansion section 22 is inclined downward relative to the bottom plate of the volute 20 in the main channel section 21. In this way, not only an expansion angle is provided to further guide the air flow and reduce its flow velocity and increase the static pressure, but also the overall structural shape of the volute 20 is more conducive to assembly and cooperation with other components.

[0102] Optionally, the expansion angle β is between 7.99 degrees and 10.81 degrees.

[0103] Optionally, the expansion angle β is between 8.46 degrees and 10.34 degrees.

[0104] Optionally, the expansion angle β is 9.4 degrees.

[0105] In one embodiment, refer to Figure 7 , the housing outlet 202 of the volute 20 is formed by chamfering. In other words, at the end of the outward expansion section 22 of the volute 20, the end of the outward expansion section 22 of the volute 20 is cut by an inclined plane, and the outlet after chamfering is used as the housing outlet 202. Please continue to refer to Figure 7 , the chamfering angle of the housing outlet 202 is γ, the plane where the housing outlet 202 is located is the first plane, the plane on the side of the expansion section of the volute 20 away from the central axis 103 is the second plane, and the plane perpendicular to the second plane is the third plane. The included angle between the first plane and the third plane is the chamfering angle γ.

[0106] Among them, the chamfering angle γ is between 8 degrees and 20 degrees. The chamfering method provides the housing outlet 202 of the volute 20 to increase the area of the outlet of the volute 20, further improving the static pressure recovery ability of the volute 20 and achieving the goal of improving the overall efficiency of the machine. Among them, the larger the chamfering angle, the larger the outlet area of the volute 20 and the better the expansion effect; if the chamfering angle is too large, the outlet section of the volute 20 will be shortened, which is not conducive to the rectification and uniform recovery of the air flow by the volute 20. Controlling the chamfering angle within the foregoing range is beneficial to improving the vacuum degree of the fan.

[0107] Optionally, the chamfering angle γ is between 12.75 degrees and 17.25 degrees.

[0108] Optionally, the chamfering angle γ is between 13.5 degrees and 16.5 degrees.

[0109] Optionally, the chamfering angle γ is 15 degrees.

[0110] In one embodiment, refer to Figure 10 , Figure 11 The configuration method of the impeller 10 and the volute 20 will be described:

[0111] The backward bending angle α of the blade 13 is 60.3 degrees. The ratio d / D of the diameter d of the air inlet 101 and the outer diameter D of the impeller 10 is 0.403, the diameter of the air inlet 101 is 18 mm, and the outer diameter D of the impeller 10 is 44.6 mm. The ratio h / D of the height h of the air outlet 102 and the outer diameter D of the impeller 10 is 0.0565. The number of blades 13 is 11 or 9. The minimum radial distance Tmin between the outer wall 133 of the impeller 10 and the inner wall 203 of the volute 20 is 6.2 mm, the maximum radial distance Tmax between the outer wall 133 of the impeller 10 and the inner wall 203 of the volute 20 is 8.8 mm, the expansion angle β of the volute 20 is 9.4 degrees, and the bevel angle γ of the volute 20 is 15 degrees.

[0112] In this embodiment, the design of parameters such as α, d / D, h / D, the number of blades 13, Tmin, Tmax, β, γ, etc. can optimize the performance of the impeller 10 and the volute 20. By optimizing the coordination of the impeller 10 and the volute 20, the vacuum degree of the fan can be improved and the cleaning power of the cleaning equipment can be enhanced.

[0113] In this embodiment, it is known through experiments that, when other parameters remain unchanged and the number of blades 13 is 11, the driving power of the motor is 78W ( Figure 11 (not shown), when the number of blades 13 is 9, the driving power of the motor is 70W when the fan reaches a vacuum degree of 15.5kPa.

[0114] In this embodiment, when the number of blades 13 is 9, the vacuum blower is tested. Figure 11 The test results are shown in Figure 1. When the input power is 70W and the speed is 72,500 rpm, the vacuum degree of the fan reaches 15.5kPa. When the fan is used in a sweeping robot or other cleaning equipment, it can effectively enhance the suction force to enhance the cleaning ability. It is suitable for some scenes with higher cleaning requirements, for example, when there is dust in many gaps, when it is necessary to adsorb dust mites on the surface and slightly deeper layers of the mattress, when the ground has a strong adsorption capacity for dust, when there are pets and babies at home, etc., the cleaning equipment using the fan of this embodiment can achieve deeper cleaning and adsorption, and the motor power and efficiency are appropriate.

[0115] The maximum negative pressure that the fan in the cleaning robot in the related art can generate is about 12kPa, and the cleaning power still needs to be improved. In this embodiment, through the optimized design and mutual matching of the impeller 10 and the volute 20, the motor drive power of the fan can be 70w±10w when the vacuum degree of the fan reaches 15kPa, thereby improving the cleaning ability of the cleaning robot and reducing the power consumption of the fan.

[0116] In the description of this article, it should be understood that the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0117] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0118] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0119] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. An impeller, characterized in that, It includes a first end cover (11), a second end cover (12), and a plurality of blades (13) disposed between the first end cover (11) and the second end cover (12). The second end cover (12) is provided with an air inlet (101). The central axis (103) of the impeller (10) is located in the middle of the plurality of blades (13), and the central axis (103) of the impeller (10) is located in the middle of the air inlet (101). The blade (13) is a backward-curved blade (13), and the backward-curved angle α of the blade (13) is between 58 degrees and 64 degrees. The ratio of the diameter d of the air inlet (101) to the outer diameter D of the impeller (10) is between 0.36 and 0.

44. The outer diameter D of the impeller (10) is between 40 mm and 48 mm.

2. The impeller according to claim 1, wherein The impeller (10) has an air outlet (102). The air outlet (102) is located between the first end cover (11), the second end cover (12), and adjacent blades (13). The ratio of the height h of the air outlet (102) to the outer diameter D of the impeller (10) is between 0.026 and 0.

086.

3. The impeller according to claim 2, wherein, The number of blades (13) disposed between the first end cover (11) and the second end cover (12) is 9 to 11.

4. The impeller according to claim 2, wherein, The backward-curved angle α of the blade (13) is between 59 degrees and 63 degrees. and / or, the ratio of the diameter d of the air inlet (101) to the outer diameter D of the impeller (10) is between 0.37 and 0.

43. and / or, the ratio of the height h of the air outlet (102) to the outer diameter D of the impeller (10) is between 0.036 and 0.

076. and / or, the diameter d of the air inlet (101) is between 16.3 mm and 19.7 mm. and / or, the outer diameter D of the impeller (10) is between 42.6 mm and 46.6 mm.

5. The impeller according to claim 2, characterized in that, The backward-curved angle α of the blade (13) is between 59 degrees and 61 degrees. and / or, the ratio of the diameter d of the air inlet (101) to the outer diameter D of the impeller (10) is between 0.393 and 0.

413. and / or, the ratio of the height h of the air outlet (102) to the outer diameter D of the impeller (10) is between 0.0465 and 0.0665. and / or, the diameter d of the air inlet (101) is between 17 mm and 19 mm. and / or, the outer diameter D of the impeller (10) is between 43.6 mm and 45.6 mm and / or, the height h of the air outlet (102) is between 1.52 mm and 3.52 mm.

6. A centrifugal fan, characterized in that, It includes the impeller (10) according to any one of claims 1-5, and further includes a volute (20); the volute (20) has an inner cavity, and the impeller (10) is disposed in the inner cavity.

7. The centrifugal fan according to claim 6, wherein, The adjacent two sides of the volute (20) are provided with a shell inlet (201) and a shell outlet (202). The shell inlet (201) is communicated with the inner cavity, and the shell outlet (202) is communicated with the inner cavity; the position of the shell inlet (201) corresponds to the position of the air inlet (101) of the impeller (10). The inner cavity comprises a main channel section (21) and an expansion section; in the main channel section (21), a minimum distance Tmin between an inner wall of the volute (20) and an outer circumference of the impeller (10) is between 5.27 mm and 7.13 mm; a maximum distance Tmax between an inner wall of the volute (20) and an outer circumference of the impeller (10) is between 7.48 mm and 10.12 mm; The expansion section has an expansion angle β, and the expansion angle β is between 8 degrees and 16 degrees; The bevel angle of the shell outlet (202) is γ, and the bevel angle γ is between 8 degrees and 20 degrees; the plane where the shell outlet (202) is located is a first plane, the plane on the side of the expansion section of the volute (20) away from the central axis (103) is a second plane, the plane perpendicular to the second plane is a third plane, and the angle between the first plane and the third plane is the bevel angle γ.

8. The centrifugal fan according to claim 7, characterized in that, The Tmin is between 5.58 mm and 6.82 mm, and the Tmax is between 7.92 mm and 9.68 mm; The expansion section has an expansion angle β, and the expansion angle β is between 8.46 degrees and 9.68 degrees; The shell outlet (202) has a bevel angle of γ, and the bevel angle γ is between 13.5 degrees and 16.5 degrees.

9. The centrifugal fan according to claim 7, wherein, The Tmin is 6.2 mm, and the Tmax is 8.8 mm; The expansion section has an expansion angle β, and the expansion angle β is 9.4 degrees; The shell outlet (202) has a bevel angle γ, and the bevel angle γ is 15 degrees; The centrifugal fan also includes a motor, the output shaft of which is connected to the impeller (10), and the motor is used to drive the impeller (10) to rotate; when the driving power of the motor is 70W to 80W, the vacuum degree of the impeller (10) is 15kPa.

10. A cleaning device, characterized in that, Comprising a centrifugal fan as described in any one of claims 6-9.

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