Centrifugal fan blade, centrifugal fan and air outlet device

Abstract

The application discloses centrifugal fan blades, centrifugal fans and air outlet equipment, and relates to the technical field of fan blades.The centrifugal fan blade comprises a blade group, a wheel disc and a wind ring, the blades of the blade group are arranged at intervals around the axis of the wheel disc, the two ends of the blades are respectively a mounting end and a reinforcing end, the mounting end is connected to the wheel disc, the outer edge of the reinforcing end is connected to the wind ring, and an extension structure is further connected between the reinforcing end and the wind ring, and the size of the extension structure gradually increases from the reinforcing end to the wind ring.The extension structure is added at the connection between the end of the blade and the wind ring, the shape and size of the extension structure are bionically reinforced, the strength of the connection between the blade and the wind ring is effectively improved without affecting the air volume of the fan, and the strength and the operating speed of the centrifugal fan blade are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fan blades, in particular to a centrifugal fan blade, a centrifugal fan and an air outlet device. BACKGROUND

[0002] A multi-blade centrifugal fan is a kind of centrifugal fan, the impeller of which is a multi-blade fan blade, and the working principle of the multi-blade centrifugal fan is the same as that of a conventional centrifugal fan. However, the number of blades of the multi-blade centrifugal fan is generally larger than that of the conventional centrifugal fan. The multi-blade centrifugal fan has the characteristics of high pressure coefficient, large flow coefficient and low noise, and is widely used in air conditioning equipment and household electrical equipment for cooling and ventilation. According to the different materials of the fan blades, the multi-blade centrifugal fan blades can be divided into metal and non-metal blades. The metal fan blade has good strength and can operate at a high speed. However, the metal fan blade cannot be designed in a wing type, and thus has a relatively large noise. The non-metal fan blade can be designed in a wing type, has a small noise and less flow separation. However, the non-metal fan blade has poor strength and can operate at a relatively low speed.

[0003] During operation of the multi-blade centrifugal fan, the blades are subjected to a centrifugal force generated by the operation of the fan blade. At the same time, the high-speed rotating centrifugal fan blade accelerates and changes the flow direction of the gas, so that the blades are subjected to a relatively large impact force. The non-metal centrifugal fan blade has a relatively low strength and generally cannot withstand the impact force at a high speed. Therefore, metal fan blades are generally used in application scenarios with high requirements for the strength of the fan blades of the multi-blade centrifugal fan. However, the use of metal fan blades cannot guarantee excellent noise indicators. With the intensification of market competition, the metal fan blades with good strength cannot meet the noise requirements of users for products.

[0004] In order to improve the strength of the blades of the non-metal centrifugal fan blade, a conventional method is to design a wind ring at the outer edge of the blade in the air inlet section, and the end portion of the blade is connected to the wind ring. The stress is concentrated at this position, and the structure is weak. Therefore, the strength of the fan blade can only meet the requirements at a low speed. When the speed is relatively high, the connection position between the blade and the wind ring is prone to breakage, so that the speed range of the non-metal centrifugal fan blade is very limited.

[0005] Therefore, how to design a centrifugal fan blade with improved blade strength and reliability is a technical problem to be solved in the industry. SUMMARY

[0006] In order to solve the defect of low strength of the existing centrifugal fan blade, the present application provides a centrifugal fan blade, a centrifugal fan and an air outlet device. The centrifugal fan blade is provided with an extension structure at the connection position between the end portion of the blade and the wind ring. The extension structure is designed by biomimetic strengthening, so as to effectively solve the problems of weak structure and stress concentration at the contact position between the blade and the wind ring, and improve the strength and operating speed of the centrifugal fan blade.

[0007] The technical scheme adopted by the present application is that a centrifugal fan blade is designed, which comprises a blade set, a wheel disc and a wind ring, the blades of the blade set are arranged at intervals around the axis of the wheel disc, the two ends of the blade are respectively an installation end and a reinforcing end, the installation end is connected to the wheel disc, the outer edge of the reinforcing end is connected to the wind ring, and an extension structure is further connected between the reinforcing end and the wind ring, and the size of the extension structure gradually increases from the reinforcing end to the wind ring.

[0008] Preferably, the length between the reinforcing end and the installation end of the blade is l, the total length of the extension structure along the length direction of the blade is k, and the value range of k is 0.05*l-0.08*l.

[0009] Preferably, the extension structure is provided with a supporting surface in contact with the wind ring, the thickness of the middle position of the supporting surface along the radial direction of the wind ring is n, the lengths of the two sides of the supporting surface are respectively e and f, the values of n, e and f are the same, and the value range of n, e and f is 0.4*(d-c)-0.6*(d-c); wherein d is the outer edge radius of the wind ring, and c is the outer edge radius of the blade.

[0010] Preferably, the length between the reinforcing end and the installation end of the blade is l, the height of the wind ring along the axial direction is s, and the remaining length of the blade after removing the contact part with the wind ring is z, z=l-s.

[0011] Preferably, the cavity between the two adjacent blades forms a blade channel, the outer edge of the blade channel is an outlet, the width of the outlet near the wind ring is y, and the width of the outlet near the wheel disc is x; the two sides of the extension structure are provided with a wing part extending to the outlet, the overlapping part of the wing part and the outlet is a wind blocking area, the length of the wind blocking area is p, and the width of the wind blocking area is q.

[0012] Preferably, the outlet area of a single blade channel is 0.5*(x+y)*(l-s), the approximate value of the area of the wind blocking area is 0.5*p*q, and 0.5*p*q≤0.005*(x+y)*(l-s).

[0013] Preferably, the extension structure is provided with an outer surface connected between the blade and the wind ring, the contact position of the outer surface and the wind ring forms a first type line, the contact position of the outer surface and the blade forms a second type line, the length of the first type line is h, and the length of the second type line is g.

[0014] The cavity between the two adjacent blades forms a blade channel, the outer edge of the blade channel is an outlet, and the width of the outlet near the wind ring is y.

[0015] The value range of h is The value range of g is

[0016] Wherein, c is the outer edge radius of the blade, and m is the number of blades of the blade set.

[0017] Preferably, the extension structure is provided with an outer surface connected between the blade and the wind ring, the edge lines on both sides of the outer surface are respectively the third type line and the fourth type line, the third type line and the fourth type line are symmetrically distributed; the cavity between the adjacent two blades forms a blade channel, the outer edge of the blade channel is an outlet, the width of the outlet near the wind ring is y, the radius of the third type line and the fourth type line is b, the value range of b is 0.45×y-0.55×y.

[0018] In some embodiments, the centrifugal fan blade is a multi-wing centrifugal fan blade, and the reinforced end of each blade is provided with an extension structure.

[0019] In some embodiments, the centrifugal fan blade is made of non-metallic material.

[0020] The application further provides a centrifugal fan, which comprises a volute, the above-mentioned centrifugal fan blade installed in the volute, and a motor for driving the centrifugal fan blade to rotate, and the centrifugal fan can be a single-inlet centrifugal fan or a double-inlet centrifugal fan.

[0021] The application further provides an air outlet device with the above-mentioned centrifugal fan blade.

[0022] In some embodiments, the air outlet device is an air conditioning system.

[0023] Compared with the prior art, the application increases the extension structure at the connection between the end of the blade and the wind ring, and performs biomimetic strengthening design on the shape and size of the extension structure, so that the strength of the connection between the blade and the wind ring is effectively improved, and the strength and the operating speed of the centrifugal fan blade are improved without affecting the air volume of the fan. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application will be described in detail below in combination with embodiments and drawings, in which:

[0025] Figure 1 is a perspective view of the centrifugal fan blade of the application;

[0026] Figure 2 is Figure 1 is an enlarged view of the extension structure at A in FIG. 4;

[0027] Figure 3 is a sectional view of the connection between the blade and the wind ring of the application;

[0028] Figure 4 is a top view of the extension structure of the application;

[0029] Figure 5 is a size marking view of the outlet of the blade channel of the application;

[0030] Figure 6 is a front view of the extension structure of the application;

[0031] Figure 7 is a perspective view of a centrifugal fan according to the present application. DETAILED DESCRIPTION

[0032] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present patent and do not limit the present patent.

[0033] The extension structure design prolongs the centrifugal fan blade, for example, the multi-wing type centrifugal fan blade. After the wing type design of the blade of the multi-wing type centrifugal fan blade, the noise is small and the flow separation is less. However, the blade processing is difficult and the precision requirement is high. The metal fan blade cannot meet the processing conditions. Therefore, the application scene with high noise requirement for the multi-wing type centrifugal fan blade generally uses a non-metal fan blade. Although the connection position between the blade and the fan ring of the non-metal fan blade is relatively weak, the stress value can be obviously reduced by increasing the extension structure at the connection position, the highest operating speed of the centrifugal fan blade is improved, the strength of the non-metal centrifugal fan blade is ensured at a low noise level, the operating speed and reliability of the non-metal centrifugal fan blade are improved.

[0034] Specifically, as shown in Figure 1 , 2 The centrifugal fan blade 1 includes a blade group, a disc 14 and a fan ring 13. The blade group is located at the edge of the disc 14. The blade group is composed of a plurality of blades 11 with the same shape. The blades 11 of the blade group are arranged at intervals around the axis of the disc 14. The two ends of the blade 11 are a mounting end 111 and a reinforcing end 112, respectively. The mounting end 111 is connected to the disc 14. The outer edge of the reinforcing end 112 is connected to the fan ring 13. The reinforcing end 112 and the fan ring 13 are also connected to the extension structure 12. The size of the extension structure 12 gradually increases from the reinforcing end 112 to the fan ring 13. The strength of the connection position of the reinforcing end 112 and the fan ring 13 is improved by the extension structure 12, which prevents it from being broken due to high speed, thereby effectively increasing the operating speed of the non-metal centrifugal fan blade. It should be understood that in actual application, in order to better improve the strength of the centrifugal fan blade, the number of the extension structure 12 is consistent with the number of the blades m, that is, the reinforcing end 112 of each blade 11 is provided with an extension structure.

[0035] The shape of the extension structure 12 uses a bionic reinforcement design similar to the wing-like hard fin of a skate. The size and shape of the extension structure 12 will be described in detail below.

[0036] As shown in Figures 3 to 5As shown, the length between the reinforced end 112 of the blade 11 and the mounting end 111 is l, the total length of the extension structure 12 along the length direction of the blade is k, and k ranges from 0.05xl to 0.08xl. The extension structure 12 is provided with a supporting surface in contact with the wind ring 13, the thickness of the supporting surface at the middle position along the radial direction of the wind ring 13 is n, the thickness of the extension structure 12 gradually increases from the reinforced end 112 to the wind ring 13, the extension structure 12 is provided with an outer surface connected between the blade 11 and the wind ring 13, and the outer surface of the extension structure 12 is a bevel from the side of the extension structure 12. The lengths of the lines on both sides of the supporting surface are e and f respectively, and n, e and f have the same value, i.e. the thickness of the supporting surface at each position along the radial direction of the wind ring 13 is uniform, so as to ensure the force balance of the extension structure at each position during the rotation of the centrifugal fan blade 1 and improve the strength of the fan blade. The value range of n, e and f is 0.4×(d-c) to 0.6×(d-c), d is the outer radius of the wind ring, and c is the outer radius of the blade. The extension structure 12 in this range has the best force performance.

[0037] The length between the reinforced end 112 of the blade 11 and the mounting end 111 is l, the height of the wind ring 13 along the axial direction is s, and the remaining length of the blade 11 after removing the contact part with the wind ring 13 is z. Therefore, zl-s, i.e. the end surface of the reinforced end 112 is flush with the end surface of the wind ring 13, the connection area between the wind ring 13 and the blade 11 is large, the structural strength of the connection position is improved, and the appearance of the centrifugal fan blade 1 is not affected. The cavity between the adjacent two blades 11 forms a blade channel 15, the outer edge of the blade channel 15 is an outlet, the airflow in the blade channel 15 flows out from the outlet, the width of the outlet near the wind ring is y, the width of the outlet near the wheel disc is x, and the outlet area of a single blade channel 15 is 0.5×(x+y)×(l-s). The two sides of the extension structure 12 are provided with a wing part extending to the outlet, the wing part is designed to enable the extension structure to withstand greater impact force, and the connection between the blade 11 and the wind ring 13 is more reliable and has higher strength.

[0038] The extension structure 12 can be a circular arc, a straight line segment or a spline curve. Through simulation calculation, it is found that the extension structure 12 with different shapes has certain effect on increasing the strength of the fan blade. However, the wing part is located at the outlet of the blade channel 15, the overlapping part of the wing part and the outlet is a wind blocking area, the length of the wind blocking area is p, the width of the wind blocking area is q, and the approximate area of the wind blocking area is 0.5×p×q. The wind blocking area will hinder the airflow flowing out from the outlet to a certain extent, and therefore the area of the wind blocking area will have certain influence on the air volume. In order to increase the strength of the fan blade while ensuring the air volume of the fan blade, the value range of the approximate area of the wind blocking area is 0.5×p×q≤0.005×(x+y)×(l-s), which is the design principle of the wing part and can meet the requirements of strength and air volume at the same time.

[0039] As shown in FIG. 1, the centrifugal fan blade 1 comprises a blade 11 and a wind ring 13. Figure 6As shown, the contact position of the outer surface of the extension structure 12 with the wind ring 13 forms a first profile line 121, and the contact position of the outer surface of the extension structure 12 with the blade 11 forms a second profile line 123, the length of the first profile line 121 is h, the length of the second profile line 123 is g, the length h of the first profile line 121 is greater than the length g of the second profile line 123, and the value range of h is The value range of g is wherein c is the outer edge radius of the blade 11, and m is the number of blades of the blade set. Since the length g of the first profile line 121 and the length h of the second profile line 123 directly affect the outer surface area of the extension structure 12, and the part of the outer surface of the extension structure 12, i.e., the wing part, extends to the outlet, the size of the area of this part is directly related to the strength and air volume of the fan blade, and therefore it is necessary to limit the length g of the first profile line 121 and the length h of the second profile line 123 within an appropriate range to reduce the influence on the blade channel 15, ensure the air volume of the centrifugal fan blade, and at the same time play a role in improving the strength of the centrifugal fan blade.

[0040] The edge lines on both sides of the outer surface of the extension structure 12 are a third profile line 122 and a fourth profile line 124, and the third profile line 122 and the fourth profile line 124 are symmetrically distributed, the first profile line 121, the second profile line 123, the third profile line 122, and the fourth profile line 124 together enclose the outer surface of the extension structure 12, the shape of the third profile line 122 and the fourth profile line 124 determines the shape of the wing part of the extension structure 12, and further affects the area of the wind blocking area, and therefore the size thereof is directly related to the strength and air volume of the fan blade. In some embodiments, the third profile line 122 and the fourth profile line 124 are circular arcs, and the radius of the circular arc is b, and the value range of b is 0.45x y~0.55x y, so as to avoid that the area of the wing part is too large to affect the air outlet of the blade channel, or the area of the wing part is too small to play a role in improving the strength of the fan blade.

[0041] Taking a non-metallic multi-wing centrifugal fan blade as an example, the inventor obtains, through experimental statistics on the improved centrifugal fan blade, that compared with a conventional multi-wing centrifugal fan blade, the stress value at the contact position of the blade 11 with the wind ring 13 is reduced by 41.5% at the same speed, the highest operating speed of the centrifugal fan blade is increased by 30.5%, the stress value Max of the conventional centrifugal fan blade is 15.57 MPa, and the stress value Max of the bionic reinforced high-strength centrifugal fan blade is 9.114 MPa, and therefore the present application has a significant effect on improving the strength of the centrifugal fan blade.

[0042] As shown in the drawings, Figure 7As shown, the application also proposes a centrifugal fan, comprising: a volute 3, the above-mentioned centrifugal fan blade 1 installed in the volute 3, and a motor 2 driving the centrifugal fan blade 1 to rotate, the centrifugal fan blade 1 is connected with the motor 2 through bolts and is fixed to the volute 3 through bolts, together forming the whole centrifugal fan, which can be a single-inlet centrifugal fan or a double-inlet centrifugal fan, that is, the above-mentioned centrifugal fan blade 1 is not only applicable to a single-inlet centrifugal fan, but also applicable to a double-inlet centrifugal fan. When the centrifugal fan operates, air flows from the inlet into the centrifugal fan blade 1, then flows out from the blade channel 15 into the volute 3, and finally is sent out from the air outlet 31 of the volute 3.

[0043] The application aims at different impeller diameters, rotating speeds and air volume requirements of the centrifugal fan, and solves the problems of weak structure and stress concentration of the blade and the air ring contact position of the centrifugal fan blade by increasing the extension structure of the blade and the air ring contact position, and by carrying out biomimetic strengthening design on the shape and size of the extension structure without affecting the air volume of the fan, so that the strength of the blade and the air ring contact position can be effectively improved, and the operating rotating speed of the centrifugal fan blade can be increased.

[0044] The centrifugal fan blade of the application can also be used in air conditioning equipment, household electrical equipment and other air outlet equipment, for example, an air conditioning system with the above-mentioned centrifugal fan blade.

[0045] It should be noted that the terms used above are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that, when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0046] The relative arrangement, numerical expressions and values of the components and steps set forth in these embodiments do not limit the scope of the application, unless otherwise specified. At the same time, it should be understood that the sizes of the various parts shown in the drawings are not drawn in proportion to the actual proportions. The techniques, methods and devices known to those skilled in the relevant art can not be discussed in detail, but should be considered as part of the authorized specification, if appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0047] In the description of the present application, it should be understood that the orientation words "inner", "outer" refer to the inner and outer relative to the contour of each component itself, and for each component or some parts on the component, the end close to the center of the centrifugal fan blade is "inner", and the end away from the center of the centrifugal fan blade is "outer". In addition, it should be pointed out that the use of "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and if there is no further declaration, the above words have no special meaning, and therefore cannot be understood as a limitation on the protection scope of the present application.

[0048] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A centrifugal fan blade, comprising: Blade set, wheel disc and wind ring, blades of the blade set are arranged at intervals around the axis of the wheel disc, both ends of the blade are mounting end and reinforcing end respectively, the mounting end is connected to the wheel disc, the outer edge of the reinforcing end is connected to the wind ring; characterized in that, the reinforcing end and the wind ring are further connected with extension structure, the size of the extension structure gradually increases from the reinforcing end to the wind ring; The extension structure is provided with an outer surface connected between the blade and the wind ring, the edge lines on both sides of the outer surface are third generatrix and fourth generatrix respectively, the third generatrix and the fourth generatrix are symmetrically distributed; The cavity between the adjacent two blades forms a blade channel, the outer edge of the blade channel is an outlet, the width of the outlet near the wind ring is y, the radius of the third generatrix and the fourth generatrix is b, the value range of b is 0.45×y~0.55×y.

2. The centrifugal fan blade of claim 1, wherein, The length between the reinforcing end and the mounting end of the blade is l, the total length of the extension structure along the length direction of the blade is k, the value range of k is 0.05×l~0.08×l.

3. The centrifugal fan blade of claim 1, wherein, The extension structure is provided with a supporting surface in contact with the wind ring, the thickness of the supporting surface at the middle position along the radial direction of the wind ring is n, the lengths of the edge lines on both sides of the supporting surface are e and f respectively, the values of n, e and f are the same, and the value range of n, e and f is 0.4×(d-c)~0.6×(d-c); wherein, d is the outer edge radius of the wind ring, and c is the outer edge radius of the blade.

4. The centrifugal fan blade of claim 1, wherein, The length between the reinforcing end and the mounting end of the blade is l, the height of the wind ring along the axial direction is s, and the remaining length of the blade after removing the contact part with the wind ring is z, z=l-s.

5. The centrifugal fan blade of claim 4, wherein, The cavity between the adjacent two blades forms a blade channel, the outer edge of the blade channel is an outlet, the width of the outlet near the wind ring is y, the width of the outlet near the wheel disc is x; The two sides of the extension structure are provided with a wing part extending to the outlet, the overlapping part of the wing part and the outlet is a wind blocking area, the length of the wind blocking area is p, and the width of the wind blocking area is q; The outlet area of a single blade channel is 0.5×(x+y)×(l-s), and the approximate area of the wind blocking area is 0.5×p×q, 0.5×p×q≤0.005×(x+y)×(l-s).

6. The centrifugal fan blade of claim 1, wherein, The extension structure is provided with an outer surface connected between the blade and the wind ring, the contact position of the outer surface and the wind ring forms a first generatrix, the contact position of the outer surface and the blade forms a second generatrix, the length of the first generatrix is h, and the length of the second generatrix is g; The cavity between the adjacent two blades forms a blade channel, the outer edge of the blade channel is an outlet, the width of the outlet near the wind ring is y; h has a value in the range of g has a value in the range of Wherein, c is the outer edge radius of the blade, and m is the number of blades of the blade set.

7. The centrifugal fan blade of claim 1, wherein The centrifugal fan blade is a multi-wing type centrifugal fan blade, and the reinforcing end of each blade is provided with the extension structure.

8. The centrifugal fan blade according to any one of claims 1 to 7, characterized in that The centrifugal fan blade is made of non-metallic material.

9. A centrifugal fan comprising: A volute, a centrifugal fan blade installed in the volute, and a motor driving the centrifugal fan blade to rotate, characterized in that the centrifugal fan blade is the centrifugal fan blade according to any one of claims 1 to 8.

10. The centrifugal fan according to claim 9, characterized in that The centrifugal fan is a single-inlet centrifugal fan or a double-inlet centrifugal fan.

11. An air outlet device, characterized by The air outlet device has the centrifugal fan blade according to any one of claims 1 to 8.

12. The air outlet device according to claim 11, characterized in that, The air outlet device is an air conditioning system.

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