Centrifugal impeller and ventilation device using same

Abstract

The invention relates to a centrifugal impeller and a ventilation device using the same. The centrifugal impeller comprises a central part, a connecting part and a plurality of blades surrounding the central part, wherein the connecting part extends outwards from the central part and is connected to the blades; the blade is bent from the radial inner side to the radial outer side, and a first included angle (alpha) formed by a first tangent line (L1) of the windward side of the blade on the radial outer side and a second tangent line (L2) of the windward side of the blade on the radial inner side is not smaller than 140 degrees and smaller than 180 degrees. Compared with a traditional straight blade scheme, the backward bent blade has larger air volume and higher efficiency, and the centrifugal impeller and the ventilation device can have better air inlet volume and efficiency.

Description

Technical Field

[0001] This invention relates to the field of ventilation, and more particularly to a centrifugal impeller and a ventilation device using such a centrifugal impeller. Background Technology

[0002] Ventilation systems are frequently used in kitchens, bathrooms, and offices. These systems typically consist of a volute, a motor, and a centrifugal impeller. Consumers desire higher efficiency and lower noise levels from these systems. The centrifugal impeller significantly impacts both efficiency and noise levels. Therefore, improvements to the centrifugal impeller are urgently needed to enhance efficiency and reduce noise. Summary of the Invention

[0003] One objective of this application is to improve the efficiency of centrifugal impellers.

[0004] To this end, the first aspect of the present invention provides a centrifugal impeller, including a central portion, a connecting portion, and a plurality of blades surrounding the central portion, wherein the connecting portion extends outward from the central portion and is connected to the plurality of blades; wherein the blades are curved from the radially inner side to the radially outer side, and a first included angle formed by a first tangent line of the windward surface of the blade at the radially outer side and a second tangent line of the windward surface of the blade at the radially inner side is not less than 140 degrees and less than 180 degrees.

[0005] In one embodiment of the present invention, the first included angle is not less than 150 degrees and less than 180 degrees.

[0006] In one embodiment of the present invention, the first included angle is not less than 160 degrees and less than 180 degrees.

[0007] In one embodiment of the present invention, the number of blades is not less than 23 and not more than 31.

[0008] In one embodiment of the present invention, the second included angle formed by the first tangent line on the windward side of the blade at the radial outer side and the third tangent line on the radial outer side of the centrifugal impeller at the radial outer side of the blade is not less than 95 degrees and does not exceed 145 degrees.

[0009] In one embodiment of the present invention, the second included angle is not less than 105 degrees and not more than 135 degrees.

[0010] In one embodiment of the present invention, the second included angle is not less than 115 degrees and not more than 125 degrees.

[0011] In one embodiment of the present invention, the third included angle formed by the second tangent on the windward side of the blade at the radially inner side and the first rotation radius at the radially inner side of the blade is not less than 50 degrees and does not exceed 80 degrees.

[0012] In one embodiment of the present invention, the third included angle is not less than 60 degrees and does not exceed 70 degrees.

[0013] In one embodiment of the present invention, the ratio of the inner diameter of the centrifugal impeller at the radial inner side of the blade to the maximum diameter of the centrifugal impeller at the radial outer side of the blade is not less than 0.55 and does not exceed 0.75.

[0014] In one embodiment of the present invention, the ratio of the inner diameter of the centrifugal impeller at the radial inner side of the blade to the maximum diameter of the centrifugal impeller at the radial outer side of the blade is not less than 0.60 and not more than 0.70.

[0015] In one embodiment of the present invention, the connecting part is a bottom cover, the inner end of the bottom cover is fixedly connected to the center part; the axial lower ends of the plurality of blades are fixedly connected to the bottom cover; the centrifugal impeller further includes a top cover, the top cover is a connecting ring, and the axial upper ends of the plurality of blades are fixedly connected to the connecting ring.

[0016] In one embodiment of the present invention, the upper axial end of the radially outer side of the blade extends further outward than the lower axial end, and the fourth included angle formed by the radially outer side of the blade and the axial direction in the projection of the longitudinal section of the centrifugal impeller is not less than 5 degrees and does not exceed 30 degrees.

[0017] In one embodiment of the present invention, the outer diameter of the bottom cover is smaller than the inner diameter of the connecting ring; the bottom cover, connecting ring, blade, center part, and connecting part are integrally formed as a one-piece unit.

[0018] In one embodiment of the present invention, the connecting ring includes a radially extending first ring body and an axially extending second ring body, the second ring body extending from the radially inner side of the first ring body and extending in a direction away from the bottom cover.

[0019] In one embodiment of the present invention, the outer diameter of the bottom cover is smaller than the inner diameter of the connecting ring; the lower axial end and the upper axial end of the radially outer side of the blade are respectively flush with the outer periphery of the bottom cover and the outer periphery of the connecting ring.

[0020] In one embodiment of the present invention, the fifth included angle formed by the first rotation radius on the radially inner side and the second rotation radius on the radially outer side of the windward surface of the blade is not less than 15 degrees and does not exceed 45 degrees.

[0021] In one embodiment of the present invention, the fifth included angle is not less than 25 degrees and does not exceed 35 degrees.

[0022] In one embodiment of the present invention, the radially inner side of the blade has an inwardly extending extension near the connecting portion, the extension being fixedly connected to the connecting portion.

[0023] Another objective of this application is to improve the efficiency of ventilation devices.

[0024] To this end, a second aspect of the present invention provides a ventilation device, including a volute and a motor installed in the volute, and further including a centrifugal impeller as described above, the centrifugal impeller being housed in the volute and being driven by the motor.

[0025] Compared with the traditional straight blade design, the backward-curved blade of the present invention has a larger air volume and higher efficiency, which enables the centrifugal impeller and ventilation device to have better air intake and efficiency. Attached Figure Description

[0026] To further reveal the specific technical content of this case, please first refer to the accompanying drawings, in which: Figure 1 and Figure 2 This is a three-dimensional schematic diagram of a centrifugal impeller provided in an embodiment of the present invention from different viewing angles; Figures 3 to 5 They are respectively Figure 1 The diagram shows the centrifugal impeller in top, bottom, and eye-level view. Figure 6 for Figure 3 A schematic diagram of the AA cross-section of the centrifugal impeller shown; Figure 7 for Figure 5 A schematic diagram of the BB cross-section of the centrifugal impeller shown; Figure 8 A perspective view of a ventilation device provided in another embodiment of the present invention; Figure 9 for Figure 8 The diagram shows the ventilation device after the front cover has been removed. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will now be described with reference to the accompanying drawings.

[0028] Please refer to Figure 1 and Figure 2 An embodiment of the present invention provides a centrifugal impeller 100 comprising a central portion 20, a connecting portion 30, and a plurality of blades 50 surrounding the central portion 20. The connecting portion 30 extends outward from the central portion 20, and the blades 50 are located on one side of the connecting portion 30 and connected to the connecting portion 30. In this embodiment, the number of blades 50 is 29; however, the present invention is not limited to this embodiment. Preferably, the number of blades is not less than 23 and not more than 31, which allows the centrifugal impeller 100 to have higher airflow and efficiency.

[0029] In this embodiment, the central portion 20 is provided with a connecting hole 22 for connecting to a drive device, such as a motor shaft. The connecting portion 30 serves as the bottom cover of the centrifugal impeller 100, and the center of the bottom cover is fixedly connected to the central portion 20. The axial lower end 54 of the blade 50 is fixedly connected to the bottom cover.

[0030] Preferably, the centrifugal impeller 100 further includes a top cover, which is a connecting ring 40. The axial upper end 52 of the blade 50 is fixedly connected to the connecting ring 40, and this structure enhances the stability of the blade 40. Further, the connecting ring 40 includes a radially extending first ring body 42 and an axially extending second ring body 44. The second ring body 44 extends radially inward from the first ring body 42 and extends in a direction away from the bottom cover. The axially extending second ring body 44 facilitates airflow guidance, further improving efficiency. The radially extending first ring body 42 increases the contact area with the blade 50, which helps to enhance the stability of the blade 50 and reduce noise.

[0031] When the centrifugal impeller 100 is working, external airflow enters the centrifugal impeller 100 axially and flows outward under the action of the blades 50. Therefore, the radially inner side 56 of the blades 50 can also be called the air inlet side, and the radially outer side 58 of the blades 50 can also be called the air outlet side. In this embodiment, an inwardly extending extension 57 is provided on the inner side of the axially lower end 54 of the blades 50. The extension 57 is mainly used to strengthen the fixed connection between the blades 50 and the connecting part 30. In this specification and claims, unless otherwise stated, it is not necessary to consider whether the blades 50 have extensions 57 when making relevant limitations based on the radially inner side 56; in other words, it cannot be considered that the extension 57 is not within the protection scope of this invention simply because the corresponding technical features of the extension 57 are different from the relevant limitations made based on the radially inner side 56.

[0032] Please refer to Figures 3 to 7 The blade 50 is curved from the radially inner side 56 to the radially outer side 58. Preferably, the blade 50 has a substantially uniform thickness, and the shape of its leeward side 53 is the same as that of the windward side 51. In this embodiment, the blade 50 extends axially as a whole, and its installation direction is substantially perpendicular to the base plate to facilitate demolding. In an alternative embodiment, the blade 50 forms a preset angle with the axial direction as a whole, for example, 1 to 5 degrees, that is, the installation direction is inclined at 1 to 5 degrees relative to the base plate to increase the smoothness of airflow and further reduce noise.

[0033] like Figure 7As shown, the first included angle α formed by the first tangent L1 of the windward surface 51 of the blade 50 at the radially outer side 58 and the second tangent L2 of the windward surface 51 of the blade 50 at the radially inner side 56 is not less than 140 degrees and less than 180 degrees. This shape of the blade 50 allows the centrifugal impeller 100 to have a larger air intake and higher efficiency. Preferably, the first included angle α is not less than 150 degrees; more preferably, the first included angle α is not less than 160 degrees. In a preferred embodiment, the first included angle α is not less than 166 degrees and less than 172 degrees. The first included angle α defines the degree of curvature of the blade 50 from the radially inner side 56 to the radially outer side 58 and defines the shape of the windward surface 51 of the blade 50. This type of blade has a larger windward surface area and higher static pressure, thereby having higher performance and efficiency.

[0034] As shown in Table 1 below, according to tests, under the same static pressure and air intake volume, compared with the traditional straight-blade impeller, the impeller provided by this invention has lower rotational speed, lower energy consumption, and lower noise. Table 1: Comparison between conventional impellers and the impeller of this invention As shown in Table 1, specifically, under the conditions of a static pressure of 0.1 inch water column (In.Wg.) and an airflow of 56 cubic inches per minute (CFM), the conventional impeller requires a rotation speed of 2520 revolutions per minute, consumes 43 watts of energy, and has a noise level of 4.0 sones (Sone@1m) at 1 meter of the impeller, with an average airflow of only 1.3 CFM / W per watt of power consumption; while the impeller of the present invention only requires a rotation speed of 2400 revolutions per minute, consumes only 18 watts of energy, and has a noise level of only 1.8 sones (Sone) at 1 meter of the impeller, with an average airflow of as high as 3.1 CFM / W per watt of power consumption.

[0035] In this claim and specification, the blade 50 with its center curved backward on the windward side 51 is referred to as a backward-curved blade. Compared to conventional straight blade designs, the backward-curved blade of this invention has a larger windward surface area, and it can concentrate airflow, resulting in higher static pressure, greater air volume, and higher efficiency. When the centrifugal impeller 100 employs 23 to 31 backward-curved blades, it achieves even better air intake and efficiency.

[0036] like Figure 3 and Figure 4As shown, the ratio of the inner diameter D1 of the centrifugal impeller 100 at the radially inner side 56 of the blade 50 to the maximum diameter D2 of the centrifugal impeller 100 at the radially outer side 58 of the blade 50 is not less than 0.55 and does not exceed 0.75. Preferably, the ratio of the inner diameter D1 to the maximum diameter D2 is not less than 0.60 and does not exceed 0.70. This ratio defines the size proportion of the blade 50 relative to the impeller, the installation position, etc. This definition, combined with the backward-curved blade 50 with the aforementioned first included angle α defined in this invention, makes it easier for the centrifugal impeller 100 to receive and exhaust air, giving the centrifugal impeller 100 a larger air intake volume and higher efficiency. As mentioned above, unless otherwise stated, in this specification and claims, when defining the inner diameter D1 based on the radially inner side 56, it is not necessary to consider whether the blade 50 has an extension 57; in other words, it cannot be considered that it is not within the protection scope of this invention simply because the inner diameter corresponding to the extension 57 is different from the inner diameter D1 defined in this invention based on the radially inner side 56.

[0037] like Figure 5 and Figure 6 As shown, the outer diameter D3 of the bottom cover is smaller than the inner diameter D4 of the connecting ring 40 to facilitate demolding during manufacturing. Preferably, the centrifugal impeller 100 is a one-piece integral unit, that is, the central part 20, the connecting part 30, the connecting ring 40, and the blades 50 are formed in one piece during manufacturing, so that the centrifugal impeller 100 is integrally formed as a single unit. Preferably, the lower axial end and the upper axial end of the radially outer side 58 of the blades 50 are flush with the outer periphery of the connecting part 30 and the outer periphery of the connecting ring 40, respectively.

[0038] Figure 7 yes Figure 5 The diagram shows a BB cross-section of the impeller. This cross-section view shows a portion of the radially outer side 58 of the blade 50, as well as the shape of the blade 50 after being truncated by the BB cross-section. Figure 7 As shown, the area on the outer side of blade 50 without a section fill line is part of the radially outer side 58 of blade 50, while the area on blade 50 with a section fill line indicates that blade 50 is truncated by section BB at that point. The centrifugal impeller 100 can rotate about its center of rotation O along the direction of rotation R0. (Reference) Figure 3 , Figures 5 to 7The second included angle β2 formed by the first tangent L1 of the windward surface 51 of the blade 50 at the radially outer side 58 and the third tangent L3 of the rotation direction R0 of the centrifugal impeller 100 at the radially outer side 58 of the blade 50 is not less than 95 degrees and not more than 145 degrees. This second included angle β2 defines the installation position or installation angle of the blade 50. This installation angle, combined with the backward-curved blade 50 with the aforementioned first included angle α as defined in this invention, makes it easier for the centrifugal impeller 100 to receive and exhaust air, giving the centrifugal impeller 100 a larger air intake and higher efficiency. The impeller obtained by combining this installation angle with the aforementioned first included angle α and the aforementioned range of the ratio of inner diameter D1 to maximum diameter D2 has a larger air intake and higher efficiency. Preferably, the second included angle β2 is not less than 105 degrees and not more than 135 degrees; more preferably, the second included angle β2 is not less than 115 degrees and not more than 125 degrees. In a preferred embodiment, the second included angle β2 is not less than 117 degrees and not more than 123 degrees.

[0039] like Figure 7 As shown, the third included angle β1 formed by the second tangent L2 of the windward surface 51 of the blade 50 at the radially inner side 56 and the first rotation radius R1 at the radially inner side 56 of the blade 50 is not less than 50 degrees and not more than 80 degrees. This third included angle β1 also defines the installation position or installation angle of the blade 50. This installation angle, combined with the backward-curved blade 50 with the aforementioned first included angle α as defined in this invention, makes it easier for the centrifugal impeller 100 to receive and exhaust air. This type of blade 50 gives the centrifugal impeller 100 a larger air intake volume and higher efficiency. The impeller obtained by defining the third included angle β1, combined with the aforementioned definition of the first included angle α and the second included angle β2, has a larger air intake volume and higher efficiency. Preferably, the third included angle β1 is not less than 60 degrees and not more than 70 degrees; more preferably, the third included angle β1 is not less than 57 degrees and not more than 63 degrees.

[0040] like Figure 5 and Figure 6As shown, the upper axial end of the radially outer side 58 of the blade 50 extends further outward than the lower axial end. The fourth included angle γ formed by the radially outer side 58 of the blade 50 and the axial direction in the projection of the longitudinal section of the centrifugal impeller 100 is not less than 5 degrees and does not exceed 30 degrees. This type of blade 50 has a larger dimension from the radially inner side 56 to the radially outer side 58 at the upper axial end, giving the blade 50 a larger windward area at the upper axial end, making it easier to receive and exhaust air, and giving the centrifugal impeller 100 a larger air intake volume and higher efficiency. Preferably, the fourth included angle γ is not less than 5 degrees and does not exceed 25 degrees. More preferably, the fourth included angle γ is not less than 20 degrees and does not exceed 24 degrees. Preferably, the radially inner side 56 of this type of blade 50 with the fourth included angle γ is substantially perpendicular to the base plate of the impeller, further ensuring that the blade 50 has a larger windward area at the upper axial end, making it easier to receive and exhaust air using the impeller 50.

[0041] like Figure 7 As shown, the fifth included angle Φ formed by the first rotation radius R1 at the radially inner side 56 and the second rotation radius R2 at the radially outer side 58 of the windward face 50 is not less than 15 degrees and does not exceed 45 degrees. This fifth included angle Φ defines the size ratio, installation position, or installation angle of the blade 50 relative to the impeller 50. This definition, combined with the backward-curved blade 50 with the aforementioned first included angle α as defined in this invention, enables the centrifugal impeller 100 to have a larger air intake and higher efficiency. Preferably, the fifth included angle Φ is not less than 20 degrees and does not exceed 40 degrees; more preferably, the fifth included angle Φ is not less than 20 degrees and does not exceed 36 degrees. The impeller obtained by defining the fifth included angle Φ, combined with defining the aforementioned first included angle α, second included angle β2 and third included angle β1, and defining the range of the ratio of the inner diameter D1 to the maximum diameter D2, has a larger air intake and higher efficiency.

[0042] The centrifugal impeller 100 provided by this invention can be used in ventilation devices. Please refer to... Figure 8 and Figure 9 Another embodiment of the present invention provides a ventilation device 200 including a volute 110, a motor 140 installed inside the volute, and the aforementioned centrifugal impeller 100. The volute 110 is provided with an air inlet duct 112 and an air outlet duct 114. The cover plate 120 of the ventilation device 200 is provided with a plurality of air inlets 122 communicating with the air inlet duct 112. The ventilation device 200 has an air outlet pipe 130 connected to the end of the air outlet duct 114, and a baffle 132 may be provided on the air outlet pipe 130. The centrifugal impeller 100 is fixedly sleeved onto the rotating shaft 142 of the motor 140, thereby being driven by the motor 140. The centrifugal impeller 100, located at the end of the air inlet duct 112, drives the gas to the air outlet duct 114.

[0043] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A centrifugal impeller, comprising a central portion, a connecting portion, and a plurality of blades surrounding the central portion, wherein the connecting portion extends outward from the central portion and connects to the plurality of blades; characterized in that, The blade is curved from the radial inner side to the radial outer side, and the first included angle (α) formed by the first tangent (L1) on the windward side of the blade at the radial outer side and the second tangent (L2) on the windward side of the blade at the radial inner side is not less than 140 degrees and less than 180 degrees.

2. The centrifugal impeller as described in claim 1, characterized in that: The first included angle (α) is not less than 150 degrees and less than 180 degrees; or The first included angle (α) is not less than 160 degrees and less than 180 degrees.

3. The centrifugal impeller as described in claim 1, characterized in that, The number of blades is not less than 23 and not more than 31.

4. The centrifugal impeller as described in claim 1, characterized in that, The second included angle (β2) formed by the first tangent (L1) on the windward side of the blade at the radial outer edge and the third tangent (L3) on the radial outer edge of the centrifugal impeller at the rotation direction of the centrifugal impeller at the radial outer edge of the blade is not less than 95 degrees and does not exceed 145 degrees.

5. The centrifugal impeller as described in claim 4, characterized in that: The second included angle (β2) is not less than 105 degrees and does not exceed 135 degrees; or The second included angle (β2) is not less than 115 degrees and does not exceed 125 degrees.

6. The centrifugal impeller as described in claim 1, characterized in that, The third included angle (β1) formed by the second tangent (L2) on the windward side of the blade and the first rotation radius (R1) on the radially inner side of the blade is not less than 50 degrees and does not exceed 80 degrees.

7. The centrifugal impeller as described in claim 6, characterized in that, The third included angle (β1) is not less than 60 degrees and does not exceed 70 degrees.

8. The centrifugal impeller as described in claim 1, characterized in that, The ratio of the inner diameter (D1) of the centrifugal impeller at the radial inner side of the blade to the maximum diameter (D2) of the centrifugal impeller at the radial outer side of the blade is not less than 0.55 and does not exceed 0.

75.

9. The centrifugal impeller as described in claim 1, characterized in that, The upper axial end of the radially outer side of the blade extends further outward than the lower axial end. The fourth included angle (γ) formed by the radially outer side of the blade and the axial direction in the projection of the longitudinal section of the centrifugal impeller is not less than 5 degrees and does not exceed 30 degrees.

10. The centrifugal impeller as claimed in claim 1, characterized in that, The connecting part is a bottom cover, and the inner end of the bottom cover is fixedly connected to the center part; the axial lower ends of the plurality of blades are fixedly connected to the bottom cover; the centrifugal impeller also includes a top cover, which is a connecting ring, and the axial upper ends of the plurality of blades are fixedly connected to the connecting ring; the outer diameter (D3) of the bottom cover is smaller than the inner diameter (D4) of the connecting ring; the bottom cover, connecting ring, blades, center part, and connecting part are integrally formed into a one-piece whole.

11. The centrifugal impeller as claimed in claim 1, characterized in that, The connecting part is a bottom cover, and the inner end of the bottom cover is fixedly connected to the center part; the axial lower ends of the plurality of blades are fixedly connected to the bottom cover; the centrifugal impeller also includes a top cover, which is a connecting ring, and the axial upper ends of the plurality of blades are fixedly connected to the connecting ring; the connecting ring includes a radially extending first ring body and an axially extending second ring body, the second ring body extending from the radially inner side of the first ring body and extending in a direction away from the bottom cover.

12. The centrifugal impeller as described in claim 10, characterized in that, The lower and upper ends of the radially outer side of the blade are flush with the outer periphery of the bottom cover and the outer periphery of the connecting ring, respectively.

13. The centrifugal impeller as described in claim 1, characterized in that, The fifth included angle (Φ) formed by the first rotation radius (R1) on the inner radial side and the second rotation radius (R2) on the outer radial side of the blade's windward surface is not less than 15 degrees and does not exceed 45 degrees.

14. The centrifugal impeller as claimed in claim 1, characterized in that, The blade has an inwardly extending extension on its radially inner side near the connecting portion, and the extension is fixedly connected to the connecting portion.

15. A ventilation device, comprising a volute and a motor mounted within the volute, characterized in that, It also includes a centrifugal impeller as described in any one of claims 1 to 14, the centrifugal impeller being housed within the volute and being driven by the motor.

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