Centrifugal fan and bladeless fan

Abstract

This utility model relates to the field of bladeless fan technology, specifically disclosing a centrifugal fan and a bladeless fan, including a volute with an air inlet and an air outlet. An impeller is installed inside the volute, and the impeller is connected to a drive component for driving the impeller to rotate. A semi-enclosed volute tongue structure is provided inside the volute near the air outlet, and a sound-absorbing chamber is formed within the volute tongue structure. A sound-absorbing component is installed in the sound-absorbing chamber. Multiple through holes are formed on the wall of the volute tongue structure near the impeller to make the volute tongue structure semi-enclosed. This allows the aerodynamic noise generated by the airflow and the mechanical noise generated by the impeller rotation to be efficiently concentrated and drawn into the sound-absorbing component through the through holes when the centrifugal fan of the bladeless fan is working, thereby improving the sound absorption and noise reduction effect and improving the user's sleep quality or user experience.

Description

Technical Field

[0001] This utility model relates to the field of bladeless fan technology, specifically to a centrifugal fan and a bladeless fan. Background Technology

[0002] Bladeless fans, also known as air multipliers, primarily work by using a centrifugal fan's impeller to draw in outside air, compress it, multiply the airflow, and then output it directionally through an outlet, producing a natural and continuous cool breeze. Because there are no rotating blades, they don't collect dust or injure children's fingers, making them safer to use compared to traditional fans. However, due to the high airflow velocity inside the centrifugal fan, aerodynamic noise is easily generated. Combined with the mechanical noise from the rotating impeller, bladeless fans can produce a relatively loud noise level during operation, potentially affecting the user's sleep quality or overall experience. Utility Model Content

[0003] The present invention aims to provide a centrifugal fan to solve the aforementioned technical problems.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows: a centrifugal fan, comprising a volute having an air inlet and an air outlet, an impeller installed inside the volute, a drive component connected to the impeller for driving the impeller to rotate, a semi-enclosed volute tongue structure provided inside the volute near the air outlet, a sound-absorbing chamber formed inside the volute tongue structure, a sound-absorbing component installed inside the sound-absorbing chamber, and multiple through holes opened on the wall of the volute tongue structure near the impeller so that the volute tongue structure is a semi-enclosed volute tongue structure.

[0005] Preferably, the volute includes a first volute and a second volute installed opposite to each other. A first enclosure wall and a second enclosure wall are respectively provided on opposite sides of the first volute and the second volute. An opening is formed on the side of the first enclosure wall and the second enclosure wall facing the impeller. A volute tongue baffle is fixedly installed between the openings of the first enclosure wall and the second enclosure wall. The first enclosure wall, the second enclosure wall, and the volute tongue baffle surround each other to form the volute tongue structure. Multiple through holes are provided on the volute tongue baffle.

[0006] Preferably, the sound-absorbing component is sound-absorbing cotton, which is squeezed against the inner wall of the sound-absorbing chamber to achieve a tight fit, and the sound-absorbing cotton is squeezed against the through hole to achieve a sealing fit; and / or a groove surface is formed on the inner wall of the volute baffle corresponding to the periphery of the through hole.

[0007] Preferably, the thickness of the sound-absorbing cotton is not less than 30mm, and the sound-absorbing cotton includes medium-density sound-absorbing cotton and high-density sound-absorbing cotton stacked together; and / or multiple through holes are arranged in a matrix, and the length e of the through holes is in the range of 10mm≤e≤100mm.

[0008] Preferably, the centrifugal fan is a forward-curved centrifugal fan, and the impeller includes at least two coaxially arranged circular frames and multiple blades connected between two adjacent circular frames. The multiple blades are arranged along the circumference of the circular frames and are curved and extended inward.

[0009] Preferably, there are three circular frames, namely the first, second and third circular frames. The blade located between the first and second circular frames is the first blade, and the blade located between the second and third circular frames is the second blade. The first blade and the second blade are arranged alternately.

[0010] Preferably, the concave surface of the blade is the windward side, and the convex surface of the blade is the leeward side. Both the windward and leeward sides are smooth curves when viewed from the side. The curvature of the curve on the windward side is less than that on the leeward side, so that the distance between two adjacent blades gradually decreases in the direction away from the center of the impeller.

[0011] Preferably, the width dimension t of the blade is in the range of 14.3mm≤t≤15.3mm; and / or the air inlet angle α at the leading edge of the windward side of the blade is in the range of 62°≤α≤64°, and the air outlet angle β at the trailing edge of the leeward side of the blade is in the range of 70°≤β≤74°; and / or the minimum distance d1 between two adjacent blades is in the range of 3.3mm≤d1≤4.3mm, and the maximum distance d2 between two adjacent blades is in the range of 7.1mm≤d2≤8.1mm.

[0012] Preferably, the length L of the volute is in the range of 185mm≤L≤200mm; the minimum distance d between the impeller and the volute tongue baffle is in the range of 6mm≤d≤9mm; and / or the radius R of the volute tongue baffle is in the range of 12mm≤R≤16mm; and / or the diameter D of the impeller is in the range of 130mm≤D≤140mm.

[0013] This utility model also provides a bladeless fan, including any of the centrifugal fans described above.

[0014] This utility model has the following beneficial effects:

[0015] (1) By setting a sound-absorbing chamber inside the volute structure at the point of maximum noise of the centrifugal fan and installing the sound-absorbing component inside the sound-absorbing chamber, the best sound absorption and noise reduction effect is achieved. The volute structure has a through hole on the wall near the impeller, while the other walls are a semi-enclosed structure composed of full enclosure. This allows the aerodynamic noise generated by the airflow and the mechanical noise generated by the impeller rotation to be efficiently concentrated and drawn into the sound-absorbing component through the through hole when the bladeless fan is working, thereby further improving the sound absorption and noise reduction effect and improving the user's sleep quality or user experience.

[0016] (2) Both the windward and leeward sides of the blades are smooth curves when viewed from the side. The curvature of the curve on the windward side is less than that on the leeward side, so that the distance between two adjacent blades gradually decreases in the direction away from the center of the impeller. The purpose is to use the principles of Bernoulli's equation and continuity equation in fluid mechanics to make the impeller have a greater airflow velocity at the air outlet, thereby improving the air outlet efficiency of the impeller. Attached Figure Description

[0017] Figure 1 This is a perspective view of an embodiment of the present invention.

[0018] Figure 2 This is a side view of an embodiment of the present invention.

[0019] Figure 3 This is an exploded view of an embodiment of the present invention.

[0020] Figure 4 This is a cross-sectional view from one perspective of an embodiment of the present invention.

[0021] Figure 5 This is a cross-sectional view from another perspective of an embodiment of the present invention.

[0022] Figure 6 This is an external view of the volute tongue baffle of an embodiment of this utility model.

[0023] Figure 7 This is an inner view of the volute tongue baffle according to an embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram of the impeller structure according to an embodiment of the present invention.

[0025] Figure 9 This is a transverse cross-sectional view of the impeller of an embodiment of this utility model.

[0026] Figure captions: 1. Volute, 11. First volute, 12. Second volute, 13. Air inlet, 14. Air outlet, 2. Impeller, 21. First circular frame, 22. Second circular frame, 23. Third circular frame, 24. First blade, 25. Second blade, 26. Windward side, 27. Leeward side, 3. Motor, 4. Volute tongue structure, 41. First enclosure, 42. Second enclosure, 43. Volute tongue baffle, 44. Sound absorption chamber, 45. Through hole, 46. Groove surface, 5. Sound absorption component. Detailed Implementation

[0027] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0028] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In addition, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] See Figure 1-9As shown, as an embodiment of this utility model, a centrifugal fan is provided, specifically a low-noise, high-efficiency forward-inclined centrifugal fan for installation in a bladeless fan. It includes a volute 1 with an air inlet 13 and an air outlet 14. An impeller 2 is installed inside the volute 1. The impeller 2 is connected to a drive component for driving the impeller 2 to rotate. The drive component is a motor 3. The motor 3 drives the impeller 2 to rotate, thereby generating airflow that is directionally output through the air outlet 14. A semi-enclosed volute tongue structure 4 is provided inside the volute 1 on the side near the air outlet 14. A sound-absorbing chamber 44 is formed inside the volute tongue structure 4. A sound-absorbing component 5 is installed inside the sound-absorbing chamber 44. Multiple through holes 45 are opened on the wall of the volute tongue structure 4 on the side near the impeller 2 so that the volute tongue structure 4 is a semi-enclosed volute tongue structure 4. Since the volute structure 4 is the noisiest point of the forward-inclined centrifugal fan, a sound-absorbing chamber 44 is placed at this location, and the sound-absorbing component 5 is installed inside the sound-absorbing chamber 44 to achieve the best sound absorption and noise reduction effect. The volute structure 4 has a through hole 45 on the wall near the impeller 2, while the other walls are a semi-enclosed structure composed of full enclosure. This allows the aerodynamic noise generated by the airflow and the mechanical noise generated by the rotation of the impeller 2 to be efficiently concentrated and drawn into the sound-absorbing component 5 through the through hole 45 when the bladeless fan is working, thereby further improving the sound absorption and noise reduction effect and improving the user's sleep quality or user experience.

[0031] In this embodiment, the volute 1 includes a first volute 11 and a second volute 12 mounted opposite to each other. A first enclosure 41 and a second enclosure 42 are respectively provided on opposite sides of the first volute 11 and the second volute 12. Openings are formed on the side of the first enclosure 41 and the second enclosure 42 facing the impeller 2. A volute tongue baffle 43 is fixedly installed between the openings of the first enclosure 41 and the second enclosure 42. The first enclosure 41, the second enclosure 42, and the volute tongue baffle 43 enclose each other to form the volute tongue structure 4. Multiple through holes 45 are provided on the volute tongue baffle 43. This structure facilitates the assembly of the volute 1 and the volute tongue structure 4, and also makes the installation and disassembly of the sound-absorbing component 5 more convenient and quick, facilitating replacement and maintenance. Furthermore, this structure of the volute 1 and the volute tongue structure 4 is more aerodynamic, resulting in lower air resistance and more efficient and stable airflow.

[0032] In this embodiment, the sound-absorbing component 5 is sound-absorbing cotton. The sound-absorbing cotton is squeezed against the inner wall of the sound-absorbing chamber 44 to achieve a tight fit, and the sound-absorbing cotton is squeezed against the through hole 45 to achieve a sealing fit, so that the sound-absorbing cotton has a better sound absorption and noise reduction effect. The inner wall of the volute tongue baffle 43 has a groove surface 46 corresponding to the periphery of the through hole 45, so that the sound-absorbing cotton and the inner wall of the volute tongue baffle 43 can achieve a tighter and more reliable squeeze fit, improving the assembly stability of the sound-absorbing cotton and the sound absorption and noise reduction effect.

[0033] Since the noise of the bladeless forward-curved centrifugal fan mainly includes aerodynamic noise generated by airflow and mechanical noise generated by the rotation of the impeller 2, with a noise frequency range between 20Hz and 1200Hz, in order to better absorb noise in this frequency range, the sound-absorbing cotton used in this embodiment has a thickness of not less than 30mm. The sound-absorbing cotton includes medium-density sound-absorbing cotton and high-density sound-absorbing cotton stacked together to improve the noise reduction effect. Multiple through holes 45 are arranged in a matrix, and the length e of the through holes 45 is in the range of 10mm≤e≤100mm to ensure the uniformity and effect of sound absorption and noise reduction. Of course, the shape of the through holes 45 can be regular or irregular, and the arrangement is not limited.

[0034] In this embodiment, the impeller 2 includes three coaxially arranged circular frames of the same diameter and multiple blades connected between two adjacent circular frames. The multiple blades are arranged along the circumference of the circular frames and extend inward in an arc shape. Specifically, the three circular frames are the first, second, and third circular frames 23. The blade located between the first circular frame 21 and the second circular frame 22 is the first blade 24, and the blade located between the second circular frame 22 and the third circular frame 23 is the second blade 25. The first blade 24 and the second blade 25 are arranged alternately, and the length of the second blade 25 is greater than the length of the first blade 24. There are 43 first blades and 43 second blades. This double-layer blade staggered structure of the impeller 2 is more aerodynamic, with less air resistance and more efficient and stable airflow. Of course, the number of first blades 24 and second blades 25 can also be other numbers, which is not limited here.

[0035] In this embodiment, the concave surface of the blade is the windward side 26, and the convex surface is the leeward side 27. Both the windward side 26 and the leeward side 27 are smooth curves in a side view. The curvature of the curve on the windward side 26 is less than that on the leeward side 27, causing the distance between adjacent blades to gradually decrease away from the center of the impeller 2. This is to utilize the principles of Bernoulli's equation and continuity equation in fluid mechanics to achieve a greater airflow velocity at the outlet 14 of the impeller 2, thereby improving the airflow efficiency of the impeller 2. Furthermore, the minimum distance d1 between adjacent blades ranges from 3.3mm ≤ d1 ≤ 4.3mm, and the maximum distance d2 between adjacent blades ranges from 7.1mm ≤ d2 ≤ 8.1mm. Specifically, the minimum distance d1 between adjacent blades is 3.8mm, and the maximum distance d2 between adjacent blades is 7.6mm.

[0036] In this embodiment, the blade width dimension t ranges from 14.3mm ≤ t ≤ 15.3mm, specifically 14.8mm; the inlet angle α at the leading edge of the windward side 26 of the blade ranges from 62° ≤ α ≤ 64°, and the outlet angle β at the trailing edge of the leeward side 27 of the blade ranges from 70° ≤ β ≤ 74°. Specifically, the inlet angle α at the leading edge of the windward side 26 of the blade is 64°, and the outlet angle β at the trailing edge of the leeward side 27 of the blade is 72°. The purpose of this angle design is to increase the curvature of the curves of the windward side 26 and the leeward side 27, thereby reducing the local turbulence formed between the volute structure 4 and the impeller 2 at the outlet 14 and improving the air outlet efficiency of the centrifugal fan.

[0037] In this embodiment, the length L of the volute 1 ranges from 185mm to 200mm, and the specific length L of the volute 1 is 192mm; the minimum distance d between the impeller 2 and the volute tongue baffle 43 ranges from 6mm to 9mm, and the specific distance d between the impeller 2 and the volute tongue baffle 43 is 7.5mm, thereby preventing airflow backflow and improving the air outlet efficiency of the impeller 2; the radius R of the volute tongue baffle 43 ranges from 12mm to 16mm, and the specific radius R of the volute tongue baffle 43 is 14mm; the diameter D of the impeller 2 ranges from 130mm to 140mm, and the specific diameter D of the impeller 2 is 135mm, further improving the air outlet efficiency of the impeller 2.

[0038] This utility model also provides a bladeless fan, including the centrifugal fan described in the above embodiments, with a centrifugal impeller 2 connected to a motor 3. Based on the national standard GB / T13380-2018, the airflow of the bladeless fan using this utility model was tested, and it was found that the airflow of the bladeless fan was 37.5 m³ / h when the drive motor 3 was at 1650 rpm. 3 / min. Under the same test conditions, the airflow Q at the highest setting of the existing bladeless fan was measured. max For Q max ≤34m³ / h. It can be seen that the maximum airflow of this bladeless fan is greater than that of several brands of bladeless fans currently on the market. By measuring the power P of the bladeless fan using this invention and existing bladeless fans at maximum airflow, the energy efficiency value η is calculated. Q max (P represents maximum air volume, and P represents power), the unit is m³ / s. 3 / min / W. The data is shown in Table 1. The energy efficiency of the bladeless fan using this invention is superior to that of existing bladeless fans.

[0039] Table 1

[0040]

[0041] According to GB / T 6882-2008, the A-weighted sound pressure level at one meter in front of the bladeless fan using this utility model was measured to be 46.5 dB(A) in a semi-anechoic chamber; and the A-weighted sound pressure level L at one meter in front of the bladeless fan of the prior art at its highest setting was also measured. Aeq The range is 47dB(A)≤L Aeq ≤49dB(A). It can be seen that the noise reduction performance of the bladeless fan of this invention is superior to that of existing bladeless fans, and its sound absorption and noise reduction effect is better.

[0042] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that any changes in form and detail made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims fall within the protection scope of the present invention.

Claims

1. A centrifugal fan, characterized in that: It includes a volute with an air inlet and an air outlet, an impeller installed inside the volute, a drive component connected to the impeller to drive its rotation, a semi-enclosed volute tongue structure provided inside the volute near the air outlet, a sound-absorbing chamber formed inside the volute tongue structure, a sound-absorbing component installed inside the sound-absorbing chamber, and multiple through holes opened on the wall of the volute tongue structure near the impeller to make the volute tongue structure a semi-enclosed volute tongue structure.

2. The centrifugal fan according to claim 1, characterized in that: The volute includes a first volute and a second volute installed opposite to each other. A first enclosure wall and a second enclosure wall are respectively provided on opposite sides of the first volute and the second volute. An opening is formed on the side of the first enclosure wall and the second enclosure wall facing the impeller. A volute tongue baffle is fixedly installed between the openings of the first enclosure wall and the second enclosure wall. The first enclosure wall, the second enclosure wall, and the volute tongue baffle are mutually enclosed to form the volute tongue structure. Multiple through holes are provided on the volute tongue baffle.

3. The centrifugal fan according to claim 2, characterized in that: The sound-absorbing component is sound-absorbing cotton, which is squeezed against the inner wall of the sound-absorbing chamber to achieve a tight fit, and the sound-absorbing cotton is squeezed against the through hole to achieve a sealing fit; and / or the inner wall of the volute baffle has a groove surface corresponding to the periphery of the through hole.

4. The centrifugal fan according to claim 3, characterized in that: The thickness of the sound-absorbing cotton is not less than 30mm. The sound-absorbing cotton includes medium-density sound-absorbing cotton and high-density sound-absorbing cotton stacked together; and / or multiple through holes arranged in a matrix, with the length e of the through holes ranging from 10mm to 100mm.

5. The centrifugal fan according to claim 1, characterized in that: The centrifugal fan is a forward-curved centrifugal fan. The impeller includes at least two coaxially arranged circular frames and multiple blades connected between two adjacent circular frames. The multiple blades are arranged along the circumference of the circular frames and are curved inwards.

6. The centrifugal fan according to claim 5, characterized in that: There are three circular frames, namely the first, second and third circular frames. The blade located between the first and second circular frames is the first blade, and the blade located between the second and third circular frames is the second blade. The first blade and the second blade are arranged alternately.

7. The centrifugal fan according to claim 5, characterized in that: The concave surface of the blade is the windward side, and the convex surface is the leeward side. Both the windward and leeward sides are smooth curves when viewed from the side. The curvature of the curve on the windward side is less than that on the leeward side, which causes the distance between two adjacent blades to gradually decrease in the direction away from the center of the impeller.

8. The centrifugal fan according to claim 7, characterized in that: The blade width dimension t ranges from 14.3mm ≤ t ≤ 15.3mm; and / or the air inlet angle α at the leading edge of the windward side of the blade ranges from 62° ≤ α ≤ 64°, and the air outlet angle β at the trailing edge of the leeward side of the blade ranges from 70° ≤ β ≤ 74°; and / or the minimum distance d1 between two adjacent blades ranges from 3.3mm ≤ d1 ≤ 4.3mm, and the maximum distance d2 between two adjacent blades ranges from 7.1mm ≤ d2 ≤ 8.1mm.

9. The centrifugal fan according to claim 2, characterized in that: The length L of the volute is in the range of 185mm≤L≤200mm; the minimum distance d between the impeller and the volute tongue baffle is in the range of 6mm≤d≤9mm; and / or the radius R of the volute tongue baffle is in the range of 12mm≤R≤16mm; and / or the diameter D of the impeller is in the range of 130mm≤D≤140mm.

10. A bladeless fan, characterized in that: The centrifugal fan includes any one of claims 1-9.

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