A centrifugal impeller, a fan and a cleaning machine having the fan

Abstract

The present invention relates to a centrifugal impeller, a fan and a cleaning machine with the fan, wherein the centrifugal impeller comprises a chassis; a cover plate arranged opposite to the chassis, the cover plate having an air inlet at a position adjacent to the center; a plurality of air guide blades arranged between the chassis and the cover plate at intervals along the circumferential direction and located at the periphery of the air inlet, an air guide channel is formed between two adjacent air guide blades, and the air guide channel is located downstream of the air inlet along the fluid flow path; the characteristic is that the outer peripheral edge of the chassis comprises at least two straight sections arranged at intervals along the circumferential direction, the two adjacent straight sections are connected by an arc section, and the arc section is bent in a direction away from the air inlet; or the outer peripheral edge of the chassis is a polygon with at least three straight sections. The airflow entering through the air inlet can decompose the noise peak after passing through the outer peripheral edge of the chassis, reduce the vortex, and make the non-steady-state vortex of the high-frequency noise peak gradually fall off, thereby suppressing the high-frequency noise.

Description

Technical Field

[0001] The invention belongs to the field of fans, and in particular relates to a centrifugal impeller, a fan and a cleaning machine with the fan. Background Art

[0002] The current floor cleaning machines with cleaning functions include vacuum cleaners and sweeping robots, which mainly adopt a brushing and sweeping method, using a fan to suck the debris on the ground into the storage box inside, thereby completing the function of floor cleaning. The current cleaning machine is provided with a motor, and the existence of the motor will generate noise.

[0003] For example, the Chinese utility model patent "A DC fan system", whose patent number is ZL201720204388.6 (authorization announcement number is CN206647283U), discloses a DC fan system, including a moving impeller, the moving impeller includes a chassis, blades centrifugally arranged on the chassis, and an upper plate covered on the blades, the upper plate is provided with an impeller air inlet, and an impeller air outlet is formed between the upper plate and the edge of the chassis; an air guide wheel, a front cover is provided on the outer side of the air guide wheel, a wind wheel air inlet is provided on the front cover, a receiving cavity for accommodating the moving impeller is formed between the air guide wheel and the front cover, the moving impeller is arranged in the receiving cavity, and a wind wheel air outlet is arranged at the bottom of the air guide wheel; a motor, the output shaft of the motor passes through the bottom of the air guide wheel and is connected to the moving impeller. When the impeller in the aforementioned fan rotates, the airflow enters through the air inlet and is forced to turn. The vortex will accumulate on the bottom plate of the impeller and fall off, thereby generating noise. If water is mixed in the airflow, the water will rotate in the impeller along with the vortex and will not be discharged smoothly.

[0004] Therefore, it is necessary to further improve the existing impeller. Summary of the invention

[0005] The first technical problem to be solved by the present invention is to provide a centrifugal impeller for suppressing high-frequency noise to achieve the purpose of noise reduction in view of the current status of the above-mentioned prior art.

[0006] The second technical problem to be solved by the present invention is to provide a centrifugal fan that can smoothly discharge the fluid.

[0007] The third technical problem to be solved by the present invention is to provide a wet and dry dual-purpose cleaning machine.

[0008] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a centrifugal impeller, comprising

[0009] Chassis;

[0010] A cover plate is arranged opposite to the chassis, and the cover plate has an air inlet near the center;

[0011] A plurality of air guide blades are arranged between the base plate and the cover plate at intervals along the circumferential direction and are located at the periphery of the air inlet, an air guide channel is formed between two adjacent air guide blades, and the air guide channel is located downstream of the air inlet along the fluid flow path;

[0012] It is characterized in that: the outer peripheral edge of the chassis includes at least two straight sections arranged at intervals along the circumferential direction, and two adjacent straight sections are connected by an arc section, and the arc section is bent away from the air inlet; or, the outer peripheral edge of the chassis is a polygon with at least 3 straight sections.

[0013] Preferably, the number of the straight segments is m, and the number of the arc segments is M, wherein m and M satisfy: 0.5M<m≤M. If m>M and m<0.5M, vortices will accumulate at the corners of the fan, generating eddy current noise.

[0014] Preferably, there are at least three straight sections, wherein two adjacent arc sections are respectively the first arc section and the second arc section, the radius of the first arc section is Ra, the radius of the second arc section is Rc, and the length of the straight section is L, wherein Ra, Rc and L satisfy: 0.2≤(Rc-Ra) / (L-Ra)≤0.8. When Ra, Rc and L do not satisfy the above range, large-order vorticity is likely to be generated, so that the fluctuation generated by the non-steady-state vortex shedding is greater than the steady-state pressure pulsation. Therefore, by adopting the above range, the fluid velocity distribution is uniform, it is not easy to generate large-order vorticity, and the noise is small.

[0015] Preferably, the profile equation of the first arc segment satisfies: Wherein, r is the radius of the inscribed circle of the straight segment, ψ is the wrap angle of the wind guide blade, β1 is the central angle of the first arc segment, and 10°≤β1≤60°.

[0016] Further preferably, the profile equation of the second arc segment satisfies: (x+rR c cosβ2) 2 +(y+R c cosβ2) 2 =R c 2 , where r is the radius of the inscribed circle of the straight segment, β2 is the central angle of the second arc segment, and 10°≤β2≤60°.

[0017] Preferably, there is one first arc segment, and the remaining arc segments are all second arc segments. In this way, the chassis adopts a mixed design of arc segments and straight segments, which can decompose the noise peak and gradually shed the unsteady vortex of the high-frequency noise peak, thereby suppressing the high-frequency noise.

[0018] In order to ensure the working capacity of the impeller with low noise, the height of the air guide blade (13) along the axial direction is Y, and the height Y, length L, radius Ra and Rc satisfy: min(Ra, L, Rc) / 12≤Y≤min(Ra, L, Rc) / 3. In this way, if the height of the air guide blade is too large, the dipole noise on the air guide blade will be too large; if the height of the air guide blade is too small, the working capacity of the impeller will be insufficient.

[0019] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a fan with the above-mentioned centrifugal impeller, characterized in that: it also includes a stator impeller and a motor, the chassis of the centrifugal impeller is installed on the output shaft of the motor, and the stator impeller includes an air outlet channel located on the periphery of the motor, and the air outlet channel is located downstream of the air guide channel along the fluid flow path.

[0020] Preferably, the fixed impeller includes a plurality of fixed blades spaced circumferentially, and the air outlet channel is formed between two adjacent fixed blades. Each fixed blade extends obliquely along a direction having an acute angle with the radial direction, so that the whole presents a clockwise or counterclockwise rotation direction in the circumferential direction. In this way, on the one hand, the fluid is guided to make the exhaust smoother. If there are water droplets at the air inlet, it is conducive to the rapid discharge of water droplets, avoiding the water droplets and the vortex airflow from falling off together and burning the motor; on the other hand, the non-steady vortex will gradually fall off, so that the fluctuations generated by the non-steady vortex shedding are much smaller than the steady-state pressure, thereby suppressing high-frequency noise.

[0021] In order to facilitate the installation of the motor, the stator impeller includes a mounting plate and an annular wall located outside the mounting plate, the stator blades are located between the mounting plate and the annular wall, and the mounting plate is provided with a through hole through which the output shaft of the power supply motor passes.

[0022] Preferably, the width of the stator blade along the radial direction is W, and the width W, radius Ra and Rc satisfy: 0.6 (Ra-Rc) ≤ Rd ≤ 1.2 (Ra-Rc). When the width of the stator blade is too large, such as greater than 1.2 (Ra-Rc), the airflow will cause vortices behind the stator blade, thereby increasing noise; when the width of the stator blade is too small, such as less than 0.6 (Ra-Rc), the airflow at the impeller outlet will be more turbulent, and the stator blade will not play a rectifying role.

[0023] Preferably, the number of the stator blades is P, and the numbers m, M and P satisfy: (mM) / P<1.

[0024] Preferably, a cover shell is provided on the outer side of the centrifugal impeller, the distance between the inner circumference of the cover shell and the outer circumference of the chassis is L1, the minimum distance between the chassis and the cover plate is L2, and the distance between the inner circumference of the cover shell and the outermost edge of the cover plate is L3, wherein L1>L2>L3.

[0025] The technical solution adopted by the present invention to solve the third technical problem mentioned above is: a cleaning machine with the above-mentioned fan, characterized in that it also includes a separation module for separating the mixture of water and dust, and the separation module is located upstream of the fan along the fluid flow path.

[0026] Compared with the prior art, the advantages of the present invention are that the outer peripheral edge of the chassis of the centrifugal impeller adopts a mixed design of arc segments and straight segments or a polygonal structure of all straight segments. The airflow entering through the air inlet can decompose the noise peak after passing through the outer peripheral edge of the chassis, reduce the vortex, and make the non-steady-state vortex of the high-frequency noise peak gradually fall off, thereby suppressing the high-frequency noise, and thus having a better noise reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the centrifugal impeller of Example 1;

[0028] Figure 2 for Figure 1 A cross-sectional view of

[0029] Figure 3 for Figure 1 Schematic diagram of the three-dimensional decomposition structure;

[0030] Figure 4 for Figure 3 A schematic diagram of a three-dimensional decomposition structure from another angle;

[0031] Figure 5 for Figure 1 Schematic diagram of the structure of the fixed impeller;

[0032] Figure 6 for Figure 5 A schematic diagram of the structure from another angle;

[0033] Figure 7 for Figure 1 A cross-sectional view of

[0034] Figure 8 for Figure 1 Schematic diagram of air flow velocity distribution at the mid-chassis;

[0035] Fig. 9 for Figure 1 Schematic diagram of turbulence distribution at the mid-chassis;

[0036] Fig.10for Figure 1 Schematic diagram of the unsteady vortex shedding at the stator blades of the stator impeller;

[0037] Fig.11 The noise diagram at the outer periphery of the chassis of the first embodiment and the second embodiment;

[0038] Fig.12 It is a partial structural schematic diagram of the cleaning machine of this embodiment;

[0039] Fig.13 It is a structural schematic diagram of the centrifugal impeller of the second embodiment;

[0040] Fig.14 for Fig.13 Schematic diagram of air flow velocity distribution at the mid-chassis;

[0041] Fig.15 for Fig.13 Schematic diagram of turbulence distribution at the mid-chassis;

[0042] Fig.16 It is a schematic diagram of the speed distribution at the chassis in the background technology;

[0043] Fig.17 Schematic diagram of turbulence distribution at the chassis in the background technology. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below with reference to the accompanying drawings.

[0045] Embodiment 1:

[0046] like Figures 1 to 12 Shown is a first preferred embodiment of the present invention.

[0047] The cleaning machine of this embodiment is a sweeper, which includes a fan, a cleaning module (not shown) for cleaning the ground, and a separation module 04 for separating a mixture of water and dust. The separation module 04 is located between the cleaning module and the fan along the fluid flow path. The separation module 04 includes a housing 4, an air inlet 400 of the housing 4 is connected to the outlet of the cleaning module, and an exhaust port of the separation module 04 is connected to the inlet of the fan. Under the action of the fan, a negative pressure is formed in the cleaning module and the separation module 04, so that dust, water and other garbage are sucked into the cleaning module through the suction port of the cleaning module, and then the gas separated by the separation module 04 is discharged. The cleaning module can use any brush head in the prior art, and the separation module can use a separation structure in the prior art, which will not be described in detail in this embodiment.

[0048] like Figure 3 and Figure 4As shown, the fan of this embodiment includes a centrifugal impeller 1, a fixed impeller 2, a motor 3 and a housing 15. The fan of this embodiment is arranged vertically, and the centrifugal impeller 1 and the fixed impeller 2 are arranged in sequence from bottom to top.

[0049] like Figure 1 and Figure 2 As shown, the centrifugal impeller 1 includes a base plate 11, a cover plate 12 and air guide blades 13. The cover plate 12 is disposed on and below the base plate 11, and the cover plate 12 has an air inlet 121 near the center. Figure 2 As shown, there are multiple air guide blades 13, which are arranged at intervals along the circumferential direction between the chassis 11 and the cover plate 12, and are located at the periphery of the air inlet 121, and are connected to the chassis 11 and the cover plate 12. An air guide channel 14 is formed between two adjacent air guide blades 13, and along the fluid flow path, the air guide channel 14 is located downstream of the air inlet 121.

[0050] like Figure 1 and Figure 4 As shown, the outer circumference of the chassis 11 includes at least two straight sections 111 arranged at intervals along the circumferential direction, and two adjacent straight sections 111 are connected by an arc section, and the arc section is bent in the direction away from the air inlet 121. The number of straight sections 111 is m, and the number of arc sections is M, wherein m and M satisfy: 0.5M<m≤M. In this embodiment, m=4, M=4, and the adjacent two arc sections in each arc section are respectively the first arc section 112 and the second arc section 113, and the other arc sections are all the second arc sections 113. Therefore, in this embodiment, there is one first arc section 112 and three second arc sections 113. The radius of the first arc section 112 is Ra, the radius of the second arc section 113 is Rc, and the length of the straight section 111 is L, and the aforementioned Ra, Rc and L satisfy: 0.2≤(Rc-Ra) / (L-Ra)≤0.8. The height of the air guide blade 13 along the axial direction is Y, and the height Y, length L, radius Ra and Rc satisfy: min(Ra, L, Rc) / 12≤Y≤min(Ra, L, Rc) / 3.

[0051] Reference Fig.16 and Fig.17 As shown, the air flow velocity distribution of the chassis in the background technology is uneven and the turbulent velocity is large, while Figure 7 As shown, the air flow velocity through the chassis of this embodiment is evenly distributed, and Figure 8 As shown in , the turbulent velocity is small when passing through the chassis. Figure 1 As shown, the profile equation of the first arc segment 112 satisfies:

[0052] Where r is the radius of the inscribed circle of the straight segment, ψ is the wrap angle of the wind guide blade, β1 is the center angle of the first arc segment, and 10°≤β1≤60°. The profile equation of the second arc segment 113 satisfies: (x+rR c cosβ2) 2 +(y+R c cosβ2) 2 =R c 2 , β2 is the center angle of the second arc segment, and 10°≤β2≤60°, and the aforementioned β1+β2=90°.

[0053] like Figure 3 As shown, the chassis 11 of the centrifugal impeller 1 is mounted on the output shaft 31 of the motor 3, and the fixed impeller 2 includes an air outlet channel 22 located at the periphery of the motor 3. Along the fluid flow path, the air outlet channel 22 is located downstream of the air guide channel 14. Specifically, as Figure 5 As shown, the stator impeller 2 includes a mounting plate 20 and an annular wall 23 located outside the mounting plate 20. A plurality of stator blades 21 are arranged circumferentially at intervals between the mounting plate 20 and the annular wall 23. The above-mentioned air outlet channel 22 is formed between two adjacent stator blades 21. Each stator blade 21 extends obliquely along a direction having an acute angle with the radial direction, so that the whole presents a clockwise or counterclockwise rotation direction in the circumferential direction. Fig.10 As shown, the non-steady-state vortex shedding effect at the stator blades is good.

[0054] like Figure 3 As shown, the width of the stator blade 21 along the radial direction is W, and the width W, radius Ra and Rc satisfy: 0.6(Ra-Rc)≤Rd≤1.2(Ra-Rc). The mounting plate 20 is provided with a through hole 201 through which the output shaft of the power supply machine 3 passes.

[0055] like Figure 7 As shown, the centrifugal impeller 1 is located in the housing 15. The housing 15 is provided with an inlet 151 connected to the air inlet 121 at a position corresponding to the air inlet 121. Figure 3 The distance between the inner periphery of the housing 15 and the outer periphery of the chassis 11 is L1, specifically, L1 is the distance between the inner periphery of the housing 15 and the straight line segment of the chassis 11, the minimum distance between the chassis 11 and the cover plate 12 is L2, and the distance between the inner periphery of the housing 15 and the outermost edge of the cover plate 12 is L3, wherein L1>L2>L3.

[0056] Depend on Fig.10It can be seen that the chassis of this embodiment can well resolve the large noise peak at 2800Hz, which is sensitive to human ears, into several small noise peaks in the 15000-20000Hz range, and move the noise peak at the sensitive part of human ears to the insensitive range of human ears. Therefore, the airflow entering through the air inlet 121 of the centrifugal impeller 1 can decompose the noise peak after passing through the outer peripheral edge of the chassis 11, reduce the vortex, and make the non-steady-state vortex of the high-frequency noise peak gradually fall off, thereby suppressing the high-frequency noise, and having a better noise reduction effect.

[0057] In the above embodiment, the number of wind guide blades is Q, the number of fixed blades is P, the least common multiple of the number m of the straight segments 111 and the number M of the arc segments is X, Q≠KX, T≠KX, (mM) / P<1. Wherein, K is a positive integer, specifically, in this embodiment, Q=11, P=10, m=4, M=4, X=4.

[0058] Embodiment 2:

[0059] like Figures 13 to 15 , which is the second preferred embodiment of the present invention. The difference between this embodiment and the above-mentioned embodiment 1 is that the structure of the outer periphery of the chassis 11 is different. Specifically, the outer periphery of the chassis 11 is a polygon with at least 3 straight sections 111. In this embodiment, there are 8 straight sections 111, and the outer periphery of the chassis 11 is an octagon. Fig.14 As shown, the air flow velocity through the chassis of this embodiment is evenly distributed, and Figure 8 As shown, the turbulent velocity passing through the chassis is relatively low. Moreover, the airflow entering through the air inlet 121 of the centrifugal impeller 1 can decompose the noise peak after passing through the outer periphery of the chassis 11, reduce the vortex, and make the non-steady vortex of the high-frequency noise peak gradually fall off, thereby suppressing the high-frequency noise, and thus having a better noise reduction effect.

Claims

1. A centrifugal impeller comprising Chassis (11); A cover plate (12) is arranged opposite to the base plate (11), and the cover plate (12) has an air inlet (121) near the center; A plurality of air guide blades (13) are arranged at intervals along the circumferential direction between the base plate (11) and the cover plate (12) and are located at the periphery of the air inlet (121); an air guide channel (14) is formed between two adjacent air guide blades (13); and along the fluid flow path, the air guide channel (14) is located downstream of the air inlet (121); Features: The outer circumference of the chassis (11) comprises at least two straight sections (111) arranged at intervals in the circumferential direction, two adjacent straight sections (111) are connected by an arc section, and the arc section is curved in a direction away from the air inlet (121); The number of the straight segments (111) is m, and the number of the arc segments is M, wherein m and M satisfy: 0.5M<m≤M; There are at least three straight sections (111), wherein two adjacent arc sections are respectively a first arc section (112) and a second arc section (113), the radius of the first arc section (112) is Ra, the radius of the second arc section (113) is Rc, and the length of the straight section (111) is L, wherein Ra, Rc and L satisfy: 0.2≤(Rc-Ra) / (L-Ra)≤0.

8.

2. The centrifugal impeller according to claim 1, characterized in that: The profile equation of the first arc segment (112) satisfies: Wherein, r is the radius of the inscribed circle of the straight segment, ψ is the wrap angle of the wind guide blade, β1 is the central angle of the first arc segment, and 10°≤β1≤60°.

3. The centrifugal impeller according to claim 1, characterized in that: The profile equation of the second arc segment (113) satisfies: (x+rR c cosβ2) 2 +(y+R c cosβ2) 2 =R c 2 , where r is the radius of the inscribed circle of the straight segment, β2 is the central angle of the second arc segment, and 10°≤β2≤60°.

4. The centrifugal impeller according to claim 3, characterized in that: There is only one first arc segment (112), and the remaining arc segments are all second arc segments (113).

5. The centrifugal impeller according to claim 1, characterized in that: The height of the wind guide blade (13) along the axial direction is Y, and the height Y, length L, radius Ra and Rc satisfy: min(Ra, L, Rc) / 12≤Y≤min(Ra, L, Rc) / 3.

6. A fan having a centrifugal impeller according to any one of claims 1 to 5, characterized in that: It also includes a stator impeller (2) and a motor (3), wherein the chassis (11) of the centrifugal impeller (1) is mounted on an output shaft (31) of the motor (3), and the stator impeller (2) includes an air outlet channel (22) located at the periphery of the motor (3), and along the fluid flow path, the air outlet channel (22) is located downstream of the air guide channel (14).

7. The fan according to claim 6, characterized in that: The stator impeller (2) comprises a plurality of stator blades (21) spaced apart in the circumferential direction, an air outlet channel (22) is formed between two adjacent stator blades (21), and each stator blade (21) extends in a direction having an acute angle with the radial direction, so that the whole presents a clockwise or counterclockwise rotation direction in the circumferential direction.

8. The fan according to claim 7, characterized in that: The stator impeller (2) comprises a mounting plate (20) and an annular wall (23) located on the periphery of the mounting plate (20); the stator blades (21) are located between the mounting plate (20) and the annular wall (23); and the mounting plate (20) is provided with a through hole (201) through which the output shaft of the power supply machine (3) passes.

9. The fan according to claim 7, characterized in that: The width of the stator blade (21) along the radial direction is W, and the width W, radius Ra and Rc satisfy: 0.6(Ra-Rc)≤Rd≤1.2(Ra-Rc).

10. The fan according to claim 7, characterized in that: The number of the stator blades is P, and the numbers m, M and P satisfy: (mM) / P<1.

11. The fan according to claim 6, characterized in that: A cover shell (15) is arranged on the outer side of the centrifugal impeller (1), the distance between the inner peripheral edge of the cover shell (15) and the outer peripheral edge of the base plate (11) is L1, the minimum distance between the base plate (11) and the cover plate (12) is L2, and the distance between the inner peripheral edge of the cover shell (15) and the outermost edge of the cover plate (12) is L3, wherein L1>L2>L3.

12. A cleaning machine having a blower according to any one of claims 6 to 11, characterized in that: It also includes a separation module (04) for separating a mixture of water and dust. Along the fluid flow path, the separation module (04) is located upstream of the fan.

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