Multi-blade centrifugal fan and impeller thereof

Abstract

The application discloses a multi-wing centrifugal fan and an impeller thereof. The multi-wing centrifugal fan impeller comprises blades, a disc, a blade connecting ring and a reinforcing piece. The blade connecting ring is arranged opposite to the disc with an interval. Two ends of the blade are arranged on the disc and the blade connecting ring respectively. One side surface of the reinforcing piece is connected with the blade, and the other side surface of the adjacent reinforcing piece is connected with the blade connecting ring. The length of the reinforcing piece along the circumferential direction of the blade connecting ring decreases from the blade connecting ring to the disc. The reinforcing piece is arranged between the blade and the blade connecting ring, and the length of the reinforcing piece along the circumferential direction of the blade connecting ring decreases from the blade connecting ring to the disc. In this way, the connecting strength of the blade and the blade connecting ring is enhanced, the structural stability of the reinforcing piece is high, the stability of the reinforcing piece when supporting the blade and the blade connecting ring is improved, and the problem of stress concentration of the reinforcing piece is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fan technology, in particular to a multi-blade centrifugal fan and an impeller thereof. BACKGROUND

[0002] The multi-blade centrifugal fan has the characteristics of high pressure coefficient, large flow coefficient and low noise, and is widely used in cooling and ventilation of air conditioning equipment and household electrical equipment. According to the material of the fan blade, the fan blades in the impeller of the multi-blade centrifugal fan are divided into two types of metal and non-metal. Among them, the metal fan blade has high strength and can operate at high speed, but it cannot be designed with a wing type and has relatively large noise. The non-metal fan blade can be designed with a wing type, has small noise and less flow separation, but has low strength and can operate at low speed.

[0003] In order to solve the problem of low connection strength of the non-metal blade, at present, the bearing capacity of the non-metal blade and the structural strength of the impeller are mainly improved by setting a reinforcing part at the connection between the non-metal blade and the blade ring. However, under special working conditions or during durable use, the reinforcing part of the general structure is still subject to the limitation of its own structure, and the problem of reinforcing failure still exists, which leads to insufficient connection strength of the non-metal blade and affects the use effect of the fan. SUMMARY

[0004] Therefore, it is necessary to provide a multi-blade centrifugal fan and an impeller thereof, which have high connection strength of the blades in the impeller.

[0005] A multi-blade centrifugal fan impeller comprises blades, a disc, a blade connecting ring and a reinforcing part. The blade connecting ring is arranged in spaced relation with the disc. The two ends of the blade are arranged on the disc and the blade connecting ring, respectively. One side of the reinforcing part is connected with the blade, and the other side is connected with the blade connecting ring. The length of the reinforcing part along the circumferential direction of the blade connecting ring decreases from the blade connecting ring to the disc.

[0006] In the above multi-blade centrifugal fan impeller, the blade is connected with the blade connecting ring, and the reinforcing part is arranged between the blade and the blade connecting ring. One side of the reinforcing part is connected with the blade, and the other side is connected with the blade connecting ring. In this way, the reinforcing part can play a supporting role to enhance the connection strength of the blade and the blade connecting ring, and is conducive to improving the operating speed of the impeller. At the same time, since the length of the reinforcing part along the circumferential direction of the blade connecting ring decreases from the blade connecting ring to the disc, the stability of the structure of the reinforcing part is high, and the stability of the reinforcing part when supporting the blade and the blade connecting ring is improved. In addition, since the contact area between the reinforcing part and the blade connecting ring is large, the stress concentration problem of the reinforcing part is improved, and the connection strength between the blade and the blade connecting ring is further improved.

[0007] The technical solutions are further described as follows:

[0008] In one of the embodiments, the side of the reinforcing member connected with the blade is a first connecting surface, the side of the reinforcing member connected with the ring is a second connecting surface, the reinforcing member further has a first supporting surface, a second supporting surface and a third supporting surface, the first supporting surface and the third supporting surface are oppositely arranged along the circumferential direction of the ring, the first connecting surface and the second supporting surface are oppositely arranged along the radial direction of the ring, the second connecting surface is arranged adjacent to the first connecting surface, the first supporting surface, the second supporting surface and the third supporting surface respectively, and the length of the first connecting surface along the circumferential direction of the ring and the length of the second supporting surface along the circumferential direction of the ring both decrease from the ring to the disc.

[0009] In one of the embodiments, the number of the blades is multiple, and the multiple blades are arranged at intervals along the circumferential direction of the ring, the first supporting surface is a concave arc surface, and the arc radius of the arc surface is r, 0.45d≤r≤0.55d, wherein d is the interval between two adjacent blades.

[0010] In one of the embodiments, the length of the second connecting surface along the radial direction of the ring is w, 0.4(r o -r i )≤w≤0.6(r o -r i ), wherein r o is the outer radius of the ring, and r i is the inner radius of the ring.

[0011] In one of the embodiments, the opposite two sides of the second connecting surface are both first arc lines, wherein the bending directions of the two first arc lines are both towards the central axis of the ring, the arc lengths of the two first arc lines are equal and both are L1, 1.25[(2πr i / n)-d]≤L1≤1.5[(2πr i / n)-d], wherein n is the number of the blades.

[0012] In one of the embodiments, the edge line of the first connecting surface away from the ring is connected with the edge line of the second supporting surface away from the ring and forms a second arc line, and the second arc line is located on the blade, the center of the second arc line is coaxially arranged with the center of the first arc line, and the arc length of the second arc line is L2, 0.15[(2πr iL2 = 0.2[(2πr i L2 = 0.2[(2πr

[0013] In one embodiment, the plurality of reinforcing members are provided, and the number of the reinforcing members is equal to the number of the blades, and each of the reinforcing members is arranged at the connecting position of each of the blades and the blade connecting ring.

[0014] In one embodiment, the blade has a suction surface and a pressure surface, and the suction surface and the pressure surface are arranged opposite to each other along the circumferential direction of the wheel disc; the inlet angle of the blade is α, and 65°≤α≤85°; the outlet angle of the blade is β, and 10°≤β≤20°.

[0015] In one embodiment, if the outlet angle β≤15°, the first support surface is arranged in the same direction as the pressure surface; if the outlet angle β>15°, the first support surface is arranged in the same direction as the suction surface.

[0016] In one embodiment, along the radial direction of the wheel disc, one end of the blade close to the central axis of the wheel disc is an air inlet end, and the other end away from the central axis of the wheel disc is an air outlet end; the distance between the air inlet end and the central axis of the wheel disc is S1, and the distance between the air outlet end and the central axis of the wheel disc is S2.

[0017] S1 / S2≥0.86, the first support surface is arranged in the same direction as the pressure surface; or S1 / S2<0.86, the first support surface is arranged in the same direction as the suction surface.

[0018] In one embodiment, the plurality of reinforcing members are provided, and the number of the reinforcing members is twice the number of the blades, and each of the reinforcing members is arranged at the connecting position of each of the blades and the blade connecting ring, wherein the reinforcing members include two reinforcing members, and the two reinforcing members are arranged opposite to each other along the circumferential direction of the blade connecting ring.

[0019] In one embodiment, along the axial direction of the wheel disc, the height of the reinforcing member is h1, and 0.05H≤h1≤0.08H, wherein H is the height of the blade along the axial direction of the wheel disc.

[0020] The application further provides a multi-blade centrifugal fan, comprising the multi-blade centrifugal fan impeller as described above. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. They illustrate exemplary embodiments of the present application and, together with their description, serve to explain the application.

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0023] In addition, the drawings are not drawn in the ratio of 1:1, and the relative sizes of the various elements are only exemplarily drawn in the drawings, but not necessarily drawn in the true ratio. In the drawings:

[0024] Figure 1 Fig. 1 is a structural schematic diagram of a multi-blade centrifugal fan in an embodiment of the present application;

[0025] Figure 2 Fig. 2 is a structural schematic diagram of an impeller of the multi-blade centrifugal fan in the first embodiment;

[0026] Figure 3 Fig. 3 is a front view of a reinforcing member in the first embodiment; Figure 2

[0027] Figure 4 Fig. 4 is a sectional view of the reinforcing member in the first embodiment; Figure 2

[0028] Fig. 5 is a structural schematic diagram of an impeller of the multi-blade centrifugal fan in the second embodiment; Figure 5

[0029] Fig. 6 is a structural schematic diagram of a circle A in the second embodiment; Figure 6 Figure 5 Fig. 7 is a front view of a set of reinforcing members in the second embodiment;

[0030] Figure 7 Figure 5 Fig. 8 is a top view of the set of reinforcing members in the second embodiment;

[0031] Figure 8 Fig. 9 is a structural schematic diagram of a blade in the impeller of the multi-blade centrifugal fan. Figure 5

[0032] Figure 9 Fig. 10 is a structural schematic diagram of a blade in the impeller of the multi-blade centrifugal fan.

[0033] The elements in the drawings are marked as follows:

[0034] 10, multi-blade centrifugal fan; 110, impeller of the multi-blade centrifugal fan; 111, blade; 1111, air inlet end; 1112, air outlet end; 112, disc; 113, blade connecting ring; 114, reinforcing member; 1141, first connecting surface; 1142, second connecting surface; 1143, first supporting surface; 1144, second supporting surface; 1145, third supporting surface. DETAILED DESCRIPTION​​​​

[0035] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a lot of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many different ways other than those described herein, and one of ordinary skill in the art can make similar improvements without departing from the spirit of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0036] Referring to Figures 1 to 6 An embodiment of the present application provides a multi-blade centrifugal fan impeller 110, comprising: blades 111, a wheel disc 112, a blade connecting ring 113 and a reinforcing member 114. The blade connecting ring 113 is arranged opposite to the wheel disc 112. Two ends of the blade 111 are arranged on the wheel disc 112 and the blade connecting ring 113 respectively. One side surface of the reinforcing member 114 is connected with the blade 111, and the other adjacent side surface is connected with the blade connecting ring 113. The length of the reinforcing member 114 along the circumferential direction of the blade connecting ring 113 decreases from the blade connecting ring 113 to the wheel disc 112.

[0037] In the multi-blade centrifugal fan impeller 110 described above, the blade 111 is connected with the blade connecting ring 113, and the reinforcing member 114 is arranged between the blade 111 and the blade connecting ring 113. One side surface of the reinforcing member 114 is connected with the blade 111, and the other adjacent side surface is connected with the blade connecting ring 113. In this way, the reinforcing member 114 can play a supporting role to enhance the connection strength between the blade 111 and the blade connecting ring 113, which is beneficial to improving the operating speed of the impeller. At the same time, since the length of the reinforcing member 114 along the circumferential direction of the blade connecting ring 113 decreases from the blade connecting ring 113 to the wheel disc 112, the reinforcing member 114 has high structural stability, which can improve the stability of the reinforcing member 114 when supporting the blade 111 and the blade connecting ring 113. In addition, since the reinforcing member 114 has a large contact area with the blade connecting ring 113, the stress concentration problem of the reinforcing member 114 can be improved, thereby further improving the connection strength between the blade 111 and the blade connecting ring 113.

[0038] Referring to Figures 2 to 4 and Figures 6 to 8In an embodiment, the side of the reinforcing member 114 connected with the blade 111 is a first connecting surface 1141. The side of the reinforcing member 114 connected with the blade connecting ring 113 is a second connecting surface 1142. The reinforcing member 114 further has a first supporting surface 1143, a second supporting surface 1144, and a third supporting surface 1145. The first supporting surface 1143 and the third supporting surface 1145 are arranged opposite to each other along the circumferential direction of the blade connecting ring 113. The first connecting surface 1141 and the second supporting surface 1144 are arranged opposite to each other along the radial direction of the blade connecting ring 113. The second connecting surface 1142 is arranged adjacent to the first connecting surface 1141, the first supporting surface 1143, the second supporting surface 1144, and the third supporting surface 1145, respectively. The length of the first connecting surface 1141 along the circumferential direction of the blade connecting ring 113 and the length of the second supporting surface 1144 along the circumferential direction of the blade connecting ring 113 both decrease from the blade connecting ring 113 to the disc 112. In this way, the stability of the reinforcing member 114 itself is increased, and the stability of the support of the blade 111 and the blade connecting ring 113 is also improved.

[0039] The reinforcing member 114 is a pentahedron structure, and the cross-sectional area of the reinforcing member 114 decreases from the blade connecting ring 113 to the disc 112. In this way, the stability of the support of the reinforcing member 114 between the blade 111 and the blade connecting ring 113 is enhanced.

[0040] Please refer to Figure 2 and Figure 3 In an embodiment, the number of the blades 111 is multiple, and the multiple blades 111 are arranged at intervals along the circumferential direction of the blade connecting ring 113. The first supporting surface 1143 is a concave circular arc surface, and the radius of the circular arc surface is r. 0.45d≤r≤0.55d, where d is the distance between two adjacent blades 111. By limiting the radius of the circular arc surface as described above, the connection strength between the blade 111 and the blade connecting ring 113 is improved without affecting the use effect of the multi-wing centrifugal fan impeller 110. Specifically, an air duct is formed between two adjacent blades 111. If the radius of the circular arc surface is too large, the reinforcing member 114 will block the air duct, thereby affecting the air outlet effect and reducing the efficiency of the multi-wing centrifugal fan impeller 110. Therefore, the radius r of the circular arc surface is ≤0.55d. If the radius of the circular arc surface is too small, the strength of the reinforcing member 114 will be reduced, thereby failing to improve the connection strength between the blade 111 and the blade connecting ring 113. Therefore, the radius r of the circular arc surface is ≥0.45d.

[0041] In the present application, the arrangement of the reinforcing member 114 can be adjusted adaptively according to the use environment of the multi-wing centrifugal fan impeller 110. Specifically, in the first embodiment, as shown in Figure 2 and Figure 3As shown, the plurality of reinforcing members 114 are provided, and the number of reinforcing members 114 is equal to the number of blades 111. Each blade 111 is provided with a reinforcing member 114 at the connecting position of the blade 111 and the blade connecting ring 113. In this way, the entire multi-blade centrifugal fan impeller 110 has high structural strength, and the operating speed of the blade 111 can be improved, and the reliability is high.

[0042] Please refer to Figure 5 and Figure 9 In an embodiment, the blade 111 has a suction surface and a pressure surface, and the suction surface and the pressure surface are arranged opposite to each other along the circumferential direction of the wheel disc 112. The inlet angle of the blade 111 is α, and 65°≤α≤85°. The outlet angle of the blade 111 is β, and 10°≤β≤20°.

[0043] Specifically, as shown in Figure 9 , the suction surface and the pressure surface of the blade 111 are both circular arc surfaces, and along the circumferential direction of the wheel disc 112, the right side of the blade 111 is the pressure surface, and the left side of the blade 111 is the suction surface.

[0044] It should be noted that the inlet angle of the blade 111 in the embodiment refers to the included angle between the tangent of the circular arc inlet of the pressure surface and the tangent of the circular ring where the inlet end 1111 of the blade 111 is located. Please refer to Figure 9 for details. The outlet angle of the blade 111 in the embodiment refers to the included angle between the tangent of the circular arc outlet of the pressure surface and the tangent of the circular ring where the outlet end 1112 of the blade 111 is located. Please refer to Figure 9 for details.

[0045] It should be noted that the circular arc inlet of the pressure surface refers to the end portion of the pressure surface close to the central axis of the wheel disc 112 along the radial direction of the wheel disc 112, and the circular arc outlet of the pressure surface refers to the end portion of the pressure surface away from the central axis of the wheel disc 112 along the radial direction of the wheel disc 112.

[0046] In an embodiment, when each blade 111 is provided with a reinforcing member 114 at the connecting position of the blade 111 and the blade connecting ring 113, the orientation of the first supporting surface 1143 of the reinforcing member 114 can be determined according to the size of the outlet angle. Specifically, if the outlet angle β≤15°, the orientation of the first supporting surface 1143 is the same as the orientation of the pressure surface. Since the blade 111 has an outlet angle β≤15°, the area of the blade 111 that is weak in strength and is in contact with the blade connecting ring 113 is close to the pressure surface, and therefore, the strength of the area can be improved by setting the orientation of the first supporting surface 1143 to be the same as the orientation of the pressure surface.

[0047] Optionally, in other embodiments, if the outlet angle β is greater than 15°, the first support surface 1143 is oriented in the same direction as the suction surface. Since the area of the vane 111 that is weak in strength and is in contact with the vane connection ring 113 is close to the suction surface when the outlet angle β of the vane 111 is greater than 15°, the strength of the area can be improved by orienting the first support surface 1143 in the same direction as the suction surface.

[0048] Alternatively, the orientation of the first support surface 1143 can also be determined by other determination methods. For example, as shown in Figure 2 and Figure 9 the inlet end 1111 of the vane 111 is close to the central axis of the wheel disc 112, and the outlet end 1112 of the vane 111 is far away from the central axis of the wheel disc 112. The distance between the inlet end 1111 of the vane 111 and the central axis of the wheel disc 112 is S1, and the distance between the outlet end 1112 of the vane 111 and the central axis of the wheel disc 112 is S2. S1 / S2≥0.86, and the first support surface 1143 is oriented in the same direction as the pressure surface. Alternatively, S1 / S2<0.86, and the first support surface 1143 is oriented in the same direction as the suction surface.

[0049] In a second embodiment, as shown in Figures 5 to 8 the reinforcing member 114 is provided in multiple numbers, and the number of the reinforcing member 114 is twice the number of the vane 111. Each vane 111 is provided with a set of reinforcing members 114 at the connection position of the vane 111 and the vane connection ring 113. Each set of reinforcing members 114 includes two reinforcing members 114, and the two reinforcing members 114 in each set of reinforcing members 114 are connected in opposite directions along the circumferential direction of the vane connection ring 113. In other words, the two reinforcing members 114 in each set of reinforcing members 114 are connected to each other by the third support surface 1145 of the reinforcing member 114. Each vane 111 is provided with a set of reinforcing members 114 at the connection position of the vane 111 and the vane connection ring 113, which can further improve the connection strength of the vane 111 and the vane connection ring 113, so that the multi-wing centrifugal fan impeller 110 can adapt to a more severe working environment, and the applicability of the multi-wing centrifugal fan 10 is improved.

[0050] When each vane 111 is provided with a set of reinforcing members 114 at the connection position of the vane 111 and the vane connection ring 113, compared with the ordinary centrifugal multi-wing fan impeller without the reinforcing member 114, the stress value at the connection position of the vane 111 and the vane connection ring 113 is reduced by 41.5% at the same speed. In addition, through tests, under the premise of ensuring safety, the maximum operating speed of the multi-wing centrifugal fan impeller 110 provided with the reinforcing member 114 is increased by 30.5%.

[0051] In an embodiment, as shown in Figure 4 and Figure 8As shown, the length of the second connecting surface 1142 along the radial direction of the blade connecting ring 113 is w, 0.4(r o -r i )≤w≤0.6(r o -r i ) in the embodiment. In the formula, r o is the outer radius of the blade connecting ring 113, and r i is the inner radius of the blade connecting ring 113. If the length of the second connecting surface 1142 along the radial direction of the blade connecting ring 113 is too large, the volume and weight of the reinforcing body will be too large, which reduces the working efficiency of the multi-wing centrifugal fan impeller 110. If the length of the second connecting surface 1142 along the radial direction of the blade connecting ring 113 is too small, the supporting effect of the reinforcing member 114 will be poor, and the connecting strength between the blade 111 and the blade connecting ring 113 cannot be improved.

[0052] It should be noted that, in the embodiment, r o -r i is the ring thickness of the blade connecting ring 113.

[0053] It should be noted that, since the blade 111 is connected to the inner circle of the blade connecting ring 113, the distance S2 between the outflow end 1112 of the blade 111 and the central axis of the wheel disc 112 is the same as the value of the inner radius r i of the blade connecting ring 113.

[0054] In an embodiment, as shown in Figures 2 to 8 , the opposite two sides of the second connecting surface 1142 are both first arc lines. The bending directions of the two first arc lines are both towards the central axis of the blade connecting ring 113. The arc lengths of the two first arc lines are equal and are both L1, 1.25[(2πr i / n)-d]≤L1≤1.5[(2πr i / n)-d] in the embodiment. In the formula, n is the number of the blades 111. If the arc length of the first arc line is too large, the volume and weight of the reinforcing body will be too large, and the air duct will be blocked, which affects the air outlet effect and reduces the working efficiency of the multi-wing centrifugal fan impeller 110. If the arc length of the first arc line is too small, the supporting effect of the reinforcing member 114 will be poor, and the connecting strength between the blade 111 and the blade connecting ring 113 will be low.

[0055] Please refer to Figure 3 , Figure 7 and Figure 8In an embodiment, the edge line of the first connecting surface 1141 away from the blade connecting ring 113 is connected to the edge line of the second supporting surface 1144 away from the blade connecting ring 113 and forms a second arc line. The second arc line is located on the blade 111. The center of the second arc line is coaxially arranged with the center of the first arc line, and the arc length of the second arc line is L2, 0.15[(2πr i / n)-d]≤L2≤0.2[(2πr i / n)-d]. Similarly, if the arc length of the second arc line is too large, the volume and weight of the reinforcing body will be too large, and the air duct will be blocked, affecting the air outlet effect and reducing the working efficiency of the multi-wing centrifugal fan impeller 110. If the arc length of the second arc line is too small, the supporting effect of the reinforcing piece 114 will be poor, and the connection strength between the blade 111 and the blade connecting ring 113 will be low.

[0056] Please refer to Figure 4 In an embodiment, the height of the reinforcing piece 114 along the axial direction of the wheel disc 112 is h1, and 0.05H≤h1≤0.08H, where H is the height of the blade 111 in the axial direction of the wheel disc 112. If the height of the reinforcing piece 114 is too large, the volume and weight of the reinforcing body will be too large, reducing the working efficiency of the multi-wing centrifugal fan impeller 110. If the height of the reinforcing piece 114 is too small, the contact area between the reinforcing piece 114 and the blade 111 will be reduced, the supporting effect will be poor, and the connection strength between the blade 111 and the blade connecting ring 113 cannot be improved.

[0057] The application also provides a multi-wing centrifugal fan 10 comprising the multi-wing centrifugal fan impeller 110 as described above.

[0058] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include at least one of the features.

[0059] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0060] In the present application, unless specifically stated and limited otherwise, a first feature "on" or "under" a second feature can be directly contacting the first and second features, or indirectly contacting the first and second features through an intervening medium. Also, a first feature "over", "above" and "on top of" a second feature can be directly above or obliquely above the second feature, or simply mean that the first feature is horizontally higher than the second feature. A first feature "under", "below" and "underneath" a second feature can be directly below or obliquely below the second feature, or simply mean that the first feature is horizontally lower than the second feature.

[0061] It is to be understood that when an element as a preamble is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements can also be present. In the description of the present application, the terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms are used for the purpose of description only and are not intended to limit the present application to a particular embodiment.

[0062] The technical features of the above embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described, however, it is to be understood that any combination of the technical features is within the scope of the present application as long as the combination does not result in a contradiction.

[0063] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A multiple-bladed centrifugal fan impeller, characterized by The application relates to a blade, a disc, a blade connecting ring and a reinforcing piece, wherein the blade connecting ring is arranged in spaced relation with the disc, two ends of the blade are arranged on the disc and the blade connecting ring respectively, one side of the reinforcing piece is connected with the blade, the other side is connected with the blade connecting ring, and the length of the reinforcing piece along the circumferential direction of the blade connecting ring decreases from the blade connecting ring to the disc. The side of the reinforcing piece connected with the blade is a first connecting surface, the reinforcing piece further has a first supporting surface, a second supporting surface and a third supporting surface, the first supporting surface and the third supporting surface are arranged in opposite relation along the circumferential direction of the blade connecting ring, the first connecting surface and the second supporting surface are arranged in opposite relation along the radial direction of the blade connecting ring, the length of the first connecting surface along the circumferential direction of the blade connecting ring and the length of the second supporting surface along the circumferential direction of the blade connecting ring both decrease from the blade connecting ring to the disc. The blade has a suction surface and a pressure surface, and the suction surface and the pressure surface are arranged in opposite relation along the circumferential direction of the disc. Along the radial direction of the disc, one end of the blade close to the central axis of the disc is an air inlet end, and the other end away from the central axis of the disc is an air outlet end, the distance between the air inlet end and the central axis of the disc is S1, and the distance between the air outlet end and the central axis of the disc is S2. Wherein S1 / S2>=0.86, the orientation of the first supporting surface is the same as that of the pressure surface; or S1 / S2<0.86, the orientation of the first supporting surface is the same as that of the suction surface. The side of the reinforcing piece connected with the blade connecting ring is a second connecting surface, and the second connecting surface is arranged in adjacent relation with the first connecting surface, the first supporting surface, the second supporting surface and the third supporting surface respectively.

2. The multi-wing centrifugal fan impeller of claim 1, wherein The number of the blades is multiple, and the multiple blades are arranged in spaced relation along the circumferential direction of the blade connecting ring, the first supporting surface is a concave circular arc surface, and the circular arc radius of the circular arc surface is r, 0.45d<=r<=0.55d, wherein d is the distance between two adjacent blades.

3. The multi-wing centrifugal fan impeller of claim 2, wherein, The number of the reinforcing pieces is equal to that of the blades, and each blade is provided with one reinforcing piece at the connecting position of the blade and the blade connecting ring.

4. The multi-wing centrifugal fan impeller of claim 3, wherein, The length of the second connecting surface in the radial direction of the blade connecting ring is w, 0.4(r o -r i )≤w≤0.6(r o -r i ), wherein r o is the outer radius of the blade connecting ring, and r i is the inner radius of the blade connecting ring.

5. The multi-wing centrifugal fan impeller of claim 4, wherein, The first arc line is arranged on the second connecting surface, and the second arc line is arranged on the third connecting surface. i The first arc line is arranged on the second connecting surface, and the second arc line is arranged on the third connecting surface. i The first arc line is arranged on the second connecting surface, and the second arc line is arranged on the third connecting surface.

6. The multi-wing centrifugal fan impeller of claim 5, wherein, The edge line of the first connecting surface away from the blade connecting ring is connected with the edge line of the second supporting surface away from the blade connecting ring and forms a second arc line, and the second arc line is located on the blade, the center of the second arc line is coaxially arranged with the center of the first arc line, and the arc length of the second arc line is L2, 0.15[(2πr i / n)-d]≤L2≤0.2[(2πr i / n)-d].

7. The multi-wing centrifugal fan impeller of any of claims 3-6, wherein, The inlet angle of the blade is alpha, 65<=alpha<=85, and the outlet angle of the blade is beta, 10<=beta<=20.

8. The multi-wing centrifugal fan impeller of claim 7, wherein, If the outlet angle beta is less than or equal to 15 degrees, the orientation of the first supporting surface is the same as that of the pressure surface; if the outlet angle beta is greater than 15 degrees, the orientation of the first supporting surface is the same as that of the suction surface.

9. The multi-wing centrifugal fan impeller of claim 8, wherein, The number of the reinforcing pieces is twice that of the blades, and each blade is provided with a group of reinforcing pieces at the connecting position of the blade and the blade connecting ring, wherein the group of reinforcing pieces comprises two reinforcing pieces, and the two reinforcing pieces in the group are connected in opposite relation along the circumferential direction of the blade connecting ring.

10. The multi-bladed centrifugal fan impeller of any of claims 3-6, wherein, ​ 11. The multi-wing centrifugal fan impeller of any of claims 1-6, wherein, A height of the reinforcing member in the axial direction of the disk is h1, and 0.05H ≤ h1 ≤ 0.08H, where H is a height of the blade in the axial direction of the disk.

12. A multiple-bladed centrifugal fan characterized by A multi-blade centrifugal fan impeller comprising the impeller of any one of claims 1-11.

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